SEQUENCE LISTING <110> Biogen MA Inc. <120> NOVEL HYBRID ACTRIIB LIGAND TRAP PROTEINS FOR TREATING MUSCLE WASTING AND BONE DISEASE <130> 2790-202CO <140> NC2019/0005115 <141> 2019-05-20 <150> 62/410,595 <151> 2016-10-20 <150> PCT/US2017/057351 <151> 2017-10-19 <160> 118 <170> PatentIn version 3.5 <210> 1 <211> 110 <212> PRT <213> Homo sapiens <400> 1 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 2 <211> 110 <212> PRT <213> Homo sapiens <400> 2 Glu Thr Gln Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Lys Phe Ser Tyr Phe Pro Glu Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 3 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 3 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 4 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 4 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 5 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 5 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 6 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 6 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 7 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 7 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 8 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 8 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 9 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 9 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 10 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 10 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Glu Lys Lys Asp Ser Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 11 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 11 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 12 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 12 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 13 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 13 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 14 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 14 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 15 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 15 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 16 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 16 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 17 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 17 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 18 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 18 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 19 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 19 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 20 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 20 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 21 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 21 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 22 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 22 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 23 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 23 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Phe Ala Thr Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 24 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 24 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 25 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 25 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 26 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 26 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 27 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 27 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 28 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 28 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Lys Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 29 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 29 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 30 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 30 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 31 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 31 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 32 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 32 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 33 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 33 Glu Thr Arg Glu Cys Ile Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 34 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 34 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Leu 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 35 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 35 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 36 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 36 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 37 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 37 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 38 <211> 330 <212> PRT <213> Homo sapiens <400> 38 Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Ser Ser Lys 1 5 10 15 Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu Val Lys Asp Tyr 20 25 30 Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu Thr Ser 35 40 45 Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu Tyr Ser 50 55 60 Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser Leu Gly Thr Gln Thr 65 70 75 80 Tyr Ile Cys Asn Val Asn His Lys Pro Ser Asn Thr Lys Val Asp Lys 85 90 95 Lys Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys Pro Pro Cys 100 105 110 Pro Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro 115 120 125 Lys Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys 130 135 140 Val Val Val Asp Val Ser His Glu Asp Pro Glu Val Lys Phe Asn Trp 145 150 155 160 Tyr Val Asp Gly Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu 165 170 175 Glu Gln Tyr Asn Ser Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu 180 185 190 His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn 195 200 205 Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly 210 215 220 Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Asp Glu 225 230 235 240 Leu Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr 245 250 255 Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn 260 265 270 Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser Phe Phe 275 280 285 Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gln Gln Gly Asn 290 295 300 Val Phe Ser Cys Ser Val Met His Glu Ala Leu His Asn His Tyr Thr 305 310 315 320 Gln Lys Ser Leu Ser Leu Ser Pro Gly Lys 325 330 <210> 39 <211> 208 <212> PRT <213> Homo sapiens <400> 39 Val Phe Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu Met Ile Ser Arg 1 5 10 15 Thr Pro Glu Val Thr Cys Val Val Val Asp Val Ser His Glu Asp Pro 20 25 30 Glu Val Lys Phe Asn Trp Tyr Val Asp Gly Val Glu Val His Asn Ala 35 40 45 Lys Thr Lys Pro Arg Glu Glu Gln Tyr Asn Ser Thr Tyr Arg Val Val 50 55 60 Ser Val Leu Thr Val Leu His Gln Asp Trp Leu Asn Gly Lys Glu Tyr 65 70 75 80 Lys Cys Lys Val Ser Asn Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr 85 90 95 Ile Ser Lys Ala Lys Gly Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu 100 105 110 Pro Pro Ser Arg Asp Glu Leu Thr Lys Asn Gln Val Ser Leu Thr Cys 115 120 125 Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser 130 135 140 Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp 145 150 155 160 Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser 165 170 175 Arg Trp Gln Gln Gly Asn Val Phe Ser Cys Ser Val Met His Glu Ala 180 185 190 Leu His Asn His Tyr Thr Gln Lys Ser Leu Ser Leu Ser Pro Gly Lys 195 200 205 <210> 40 <211> 326 <212> PRT <213> Homo sapiens <400> 40 Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Cys Ser Arg 1 5 10 15 Ser Thr Ser Glu Ser Thr Ala Ala Leu Gly Cys Leu Val Lys Asp Tyr 20 25 30 Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu Thr Ser 35 40 45 Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu Tyr Ser 50 55 60 Leu Ser Ser Val Val Thr Val Pro Ser Ser Asn Phe Gly Thr Gln Thr 65 70 75 80 Tyr Thr Cys Asn Val Asp His Lys Pro Ser Asn Thr Lys Val Asp Lys 85 90 95 Thr Val Glu Arg Lys Cys Cys Val Glu Cys Pro Pro Cys Pro Ala Pro 100 105 110 Pro Val Ala Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys Asp 115 120 125 Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val Asp 130 135 140 Val Ser His Glu Asp Pro Glu Val Gln Phe Asn Trp Tyr Val Asp Gly 145 150 155 160 Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln Phe Asn 165 170 175 Ser Thr Phe Arg Val Val Ser Val Leu Thr Val Val His Gln Asp Trp 180 185 190 Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Gly Leu Pro 195 200 205 Ala Pro Ile Glu Lys Thr Ile Ser Lys Thr Lys Gly Gln Pro Arg Glu 210 215 220 Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Glu Glu Met Thr Lys Asn 225 230 235 240 Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile 245 250 255 Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr 260 265 270 Thr Pro Pro Met Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys 275 280 285 Leu Thr Val Asp Lys Ser Arg Trp Gln Gln Gly Asn Val Phe Ser Cys 290 295 300 Ser Val Met His Glu Ala Leu His Asn His Tyr Thr Gln Lys Ser Leu 305 310 315 320 Ser Leu Ser Pro Gly Lys 325 <210> 41 <211> 207 <212> PRT <213> Homo sapiens <400> 41 Val Phe Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu Met Ile Ser Arg 1 5 10 15 Thr Pro Glu Val Thr Cys Val Val Val Asp Val Ser His Glu Asp Pro 20 25 30 Glu Val Gln Phe Asn Trp Tyr Val Asp Gly Val Glu Val His Asn Ala 35 40 45 Lys Thr Lys Pro Arg Glu Glu Gln Phe Asn Ser Thr Phe Arg Val Val 50 55 60 Ser Val Leu Thr Val Val His Gln Asp Trp Leu Asn Gly Lys Glu Tyr 65 70 75 80 Lys Cys Lys Val Ser Asn Lys Gly Leu Pro Ala Pro Ile Glu Lys Thr 85 90 95 Ile Ser Lys Thr Lys Gly Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu 100 105 110 Pro Pro Ser Arg Glu Glu Met Thr Lys Asn Gln Val Ser Leu Thr Cys 115 120 125 Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser 130 135 140 Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro Met Leu Asp 145 150 155 160 Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser 165 170 175 Arg Trp Gln Gln Gly Asn Val Phe Cys Ser Val Met His Glu Ala Leu 180 185 190 His Asn His Tyr Thr Gln Lys Ser Leu Ser Leu Ser Pro Gly Lys 195 200 205 <210> 42 <211> 327 <212> PRT <213> Homo sapiens <400> 42 Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Cys Ser Arg 1 5 10 15 Ser Thr Ser Glu Ser Thr Ala Ala Leu Gly Cys Leu Val Lys Asp Tyr 20 25 30 Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu Thr Ser 35 40 45 Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu Tyr Ser 50 55 60 Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser Leu Gly Thr Lys Thr 65 70 75 80 Tyr Thr Cys Asn Val Asp His Lys Pro Ser Asn Thr Lys Val Asp Lys 85 90 95 Arg Val Glu Ser Lys Tyr Gly Pro Pro Cys Pro Ser Cys Pro Ala Pro 100 105 110 Glu Phe Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys 115 120 125 Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val 130 135 140 Asp Val Ser Gln Glu Asp Pro Glu Val Gln Phe Asn Trp Tyr Val Asp 145 150 155 160 Gly Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln Phe 165 170 175 Asn Ser Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu His Gln Asp 180 185 190 Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Gly Leu 195 200 205 Pro Ser Ser Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly Gln Pro Arg 210 215 220 Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Gln Glu Glu Met Thr Lys 225 230 235 240 Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp 245 250 255 Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys 260 265 270 Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser 275 280 285 Arg Leu Thr Val Asp Lys Ser Arg Trp Gln Glu Gly Asn Val Phe Ser 290 295 300 Cys Ser Val Met His Glu Ala Leu His Asn His Tyr Thr Gln Lys Ser 305 310 315 320 Leu Ser Leu Ser Leu Gly Lys 325 <210> 43 <211> 217 <212> PRT <213> Homo sapiens <400> 43 Ala Pro Glu Phe Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro Lys 1 5 10 15 Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val 20 25 30 Val Val Asp Val Ser Gln Glu Asp Pro Glu Val Gln Phe Asn Trp Tyr 35 40 45 Val Asp Gly Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu 50 55 60 Gln Phe Asn Ser Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu His 65 70 75 80 Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys 85 90 95 Gly Leu Pro Ser Ser Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly Gln 100 105 110 Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Gln Glu Glu Met 115 120 125 Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro 130 135 140 Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn 145 150 155 160 Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser Phe Phe Leu 165 170 175 Tyr Ser Arg Leu Thr Val Asp Lys Ser Arg Trp Gln Glu Gly Asn Val 180 185 190 Phe Ser Cys Ser Val Met His Glu Ala Leu His Asn His Tyr Thr Gln 195 200 205 Lys Ser Leu Ser Leu Ser Leu Gly Lys 210 215 <210> 44 <211> 5 <212> PRT <213> Artificial <220> <223> Peptide linker <400> 44 Gly Gly Gly Gly Ser 1 5 <210> 45 <211> 512 <212> PRT <213> Homo sapiens <400> 45 Met Thr Ala Pro Trp Val Ala Leu Ala Leu Leu Trp Gly Ser Leu Cys 1 5 10 15 Ala Gly Ser Gly Arg Gly Glu Ala Glu Thr Arg Glu Cys Ile Tyr Tyr 20 25 30 Asn Ala Asn Trp Glu Leu Glu Arg Thr Asn Gln Ser Gly Leu Glu Arg 35 40 45 Cys Glu Gly Glu Gln Asp Lys Arg Leu His Cys Tyr Ala Ser Trp Arg 50 55 60 Asn Ser Ser Gly Thr Ile Glu Leu Val Lys Lys Gly Cys Trp Leu Asp 65 70 75 80 Asp Phe Asn Cys Tyr Asp Arg Gln Glu Cys Val Ala Thr Glu Glu Asn 85 90 95 Pro Gln Val Tyr Phe Cys Cys Cys Glu Gly Asn Phe Cys Asn Glu Arg 100 105 110 Phe Thr His Leu Pro Glu Ala Gly Gly Pro Glu Val Thr Tyr Glu Pro 115 120 125 Pro Pro Thr Ala Pro Thr Leu Leu Thr Val Leu Ala Tyr Ser Leu Leu 130 135 140 Pro Ile Gly Gly Leu Ser Leu Ile Val Leu Leu Ala Phe Trp Met Tyr 145 150 155 160 Arg His Arg Lys Pro Pro Tyr Gly His Val Asp Ile His Glu Asp Pro 165 170 175 Gly Pro Pro Pro Pro Ser Pro Leu Val Gly Leu Lys Pro Leu Gln Leu 180 185 190 Leu Glu Ile Lys Ala Arg Gly Arg Phe Gly Cys Val Trp Lys Ala Gln 195 200 205 Leu Met Asn Asp Phe Val Ala Val Lys Ile Phe Pro Leu Gln Asp Lys 210 215 220 Gln Ser Trp Gln Ser Glu Arg Glu Ile Phe Ser Thr Pro Gly Met Lys 225 230 235 240 His Glu Asn Leu Leu Gln Phe Ile Ala Ala Glu Lys Arg Gly Ser Asn 245 250 255 Leu Glu Val Glu Leu Trp Leu Ile Thr Ala Phe His Asp Lys Gly Ser 260 265 270 Leu Thr Asp Tyr Leu Lys Gly Asn Ile Ile Thr Trp Asn Glu Leu Cys 275 280 285 His Val Ala Glu Thr Met Ser Arg Gly Leu Ser Tyr Leu His Glu Asp 290 295 300 Val Pro Trp Cys Arg Gly Glu Gly His Lys Pro Ser Ile Ala His Arg 305 310 315 320 Asp Phe Lys Ser Lys Asn Val Leu Leu Lys Ser Asp Leu Thr Ala Val 325 330 335 Leu Ala Asp Phe Gly Leu Ala Val Arg Phe Glu Pro Gly Lys Pro Pro 340 345 350 Gly Asp Thr His Gly Gln Val Gly Thr Arg Arg Tyr Met Ala Pro Glu 355 360 365 Val Leu Glu Gly Ala Ile Asn Phe Gln Arg Asp Ala Phe Leu Arg Ile 370 375 380 Asp Met Tyr Ala Met Gly Leu Val Leu Trp Glu Leu Val Ser Arg Cys 385 390 395 400 Lys Ala Ala Asp Gly Pro Val Asp Glu Tyr Met Leu Pro Phe Glu Glu 405 410 415 Glu Ile Gly Gln His Pro Ser Leu Glu Glu Leu Gln Glu Val Val Val 420 425 430 His Lys Lys Met Arg Pro Thr Ile Lys Asp His Trp Leu Lys His Pro 435 440 445 Gly Leu Ala Gln Leu Cys Val Thr Ile Glu Glu Cys Trp Asp His Asp 450 455 460 Ala Glu Ala Arg Leu Ser Ala Gly Cys Val Glu Glu Arg Val Ser Leu 465 470 475 480 Ile Arg Arg Ser Val Asn Gly Thr Thr Ser Asp Cys Leu Val Ser Leu 485 490 495 Val Thr Ser Val Thr Asn Val Asp Leu Pro Pro Lys Glu Ser Ser Ile 500 505 510 <210> 46 <211> 116 <212> PRT <213> Homo sapiens <400> 46 Ser Gly Arg Gly Glu Ala Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala 1 5 10 15 Asn Trp Glu Leu Glu Arg Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu 20 25 30 Gly Glu Gln Asp Lys Arg Leu His Cys Tyr Ala Ser Trp Arg Asn Ser 35 40 45 Ser Gly Thr Ile Glu Leu Val Lys Lys Gly Cys Trp Leu Asp Asp Phe 50 55 60 Asn Cys Tyr Asp Arg Gln Glu Cys Val Ala Thr Glu Glu Asn Pro Gln 65 70 75 80 Val Tyr Phe Cys Cys Cys Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr 85 90 95 His Leu Pro Glu Ala Gly Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro 100 105 110 Thr Ala Pro Thr 115 <210> 47 <211> 513 <212> PRT <213> Homo sapiens <400> 47 Met Gly Ala Ala Thr Lys Leu Ala Phe Ala Val Phe Leu Ile Ser Cys 1 5 10 15 Ser Ser Gly Ala Ile Leu Gly Arg Ser Glu Thr Gln Glu Cys Ile Tyr 20 25 30 Tyr Asn Ala Asn Trp Glu Lys Asp Lys Thr Asn Arg Ser Gly Ile Glu 35 40 45 Pro Cys Tyr Gly Asp Lys Asp Lys Arg Arg His Cys Phe Ala Thr Trp 50 55 60 Lys Asn Ile Ser Gly Ser Ile Glu Ile Val Lys Gln Gly Cys Trp Leu 65 70 75 80 Asp Asp Ile Asn Cys Tyr Asp Arg Asn Asp Cys Ile Glu Lys Lys Asp 85 90 95 Ser Pro Glu Val Phe Phe Cys Cys Cys Glu Gly Asn Met Cys Asn Glu 100 105 110 Arg Phe Phe Tyr Phe Pro Glu Met Glu Val Thr Gln Pro Thr Ser Asn 115 120 125 Pro Val Thr Pro Lys Pro Pro Leu Phe Asn Thr Leu Leu Tyr Ser Leu 130 135 140 Val Pro Ile Met Gly Ile Ala Val Ile Val Leu Phe Ser Phe Trp Met 145 150 155 160 Tyr Arg His His Lys Leu Ala Tyr Pro Pro Val Leu Val Pro Thr Gln 165 170 175 Asp Pro Gly Pro Pro Pro Pro Ser Pro Leu Met Gly Leu Lys Pro Leu 180 185 190 Gln Leu Leu Glu Ile Lys Ala Arg Gly Arg Phe Gly Cys Val Trp Lys 195 200 205 Ala Gln Leu Leu Asn Glu Tyr Val Ala Val Lys Ile Phe Pro Ile Gln 210 215 220 Asp Lys Gln Ser Trp Gln Asn Glu Tyr Glu Ile Tyr Ser Leu Pro Gly 225 230 235 240 Met Lys His Asp Asn Ile Leu Gln Phe Ile Gly Ala Glu Lys Arg Gly 245 250 255 Thr Ser Ile Asp Val Asp Leu Trp Leu Ile Thr Ala Phe His Glu Lys 260 265 270 Gly Ser Leu Thr Asp Phe Leu Lys Ala Asn Val Val Ser Trp Asn Glu 275 280 285 Leu Cys His Ile Ala Gln Thr Met Ala Arg Gly Leu Ala Tyr Leu His 290 295 300 Glu Asp Ile Pro Gly Leu Lys Asp Gly His Lys Pro Ala Ile Ser His 305 310 315 320 Arg Asp Ile Lys Ser Lys Asn Val Leu Leu Lys Asn Asn Leu Thr Ala 325 330 335 Cys Ile Ala Asp Phe Gly Leu Ala Leu Lys Phe Glu Ala Gly Lys Ser 340 345 350 Ala Gly Asp Thr His Gly Gln Val Gly Thr Arg Arg Tyr Met Ala Pro 355 360 365 Glu Val Leu Glu Gly Ala Ile Asn Phe Gln Arg Asp Ala Phe Leu Arg 370 375 380 Ile Asp Met Tyr Ala Met Gly Leu Val Leu Trp Glu Leu Ala Ser Arg 385 390 395 400 Cys Thr Ala Ser Asp Gly Pro Val Asp Glu Tyr Met Leu Pro Phe Glu 405 410 415 Glu Glu Ile Gly Gln His Pro Ser Leu Glu Asp Met Gln Glu Val Val 420 425 430 Val His Lys Lys Lys Arg Pro Val Leu Arg Glu Cys Trp Gln Lys His 435 440 445 Ser Gly Met Ala Met Leu Cys Glu Thr Ile Glu Glu Cys Trp Asp His 450 455 460 Asp Ala Glu Ala Arg Leu Ser Ala Gly Cys Val Glu Glu Arg Ile Ile 465 470 475 480 Gln Met Gln Lys Leu Thr Asn Ile Ile Thr Thr Glu Asp Ile Val Thr 485 490 495 Val Val Thr Met Val Thr Asn Val Asp Phe Pro Pro Lys Glu Ser Ser 500 505 510 Leu <210> 48 <211> 116 <212> PRT <213> Homo sapiens <400> 48 Ala Ile Leu Gly Arg Ser Glu Thr Gln Glu Cys Leu Phe Phe Asn Ala 1 5 10 15 Asn Trp Glu Lys Asp Arg Thr Asn Gln Thr Gly Val Glu Pro Cys Tyr 20 25 30 Gly Asp Lys Asp Lys Arg Arg His Cys Phe Ala Thr Trp Lys Asn Ile 35 40 45 Ser Gly Ser Ile Glu Ile Val Lys Gln Gly Cys Trp Leu Asp Asp Ile 50 55 60 Asn Cys Tyr Asp Arg Thr Asp Cys Val Glu Lys Lys Asp Ser Pro Glu 65 70 75 80 Val Tyr Phe Cys Cys Cys Glu Gly Asn Met Cys Asn Glu Lys Phe Ser 85 90 95 Tyr Phe Pro Glu Met Glu Val Thr Gln Pro Thr Ser Asn Pro Val Thr 100 105 110 Pro Lys Pro Pro 115 <210> 49 <211> 18 <212> PRT <213> Artificial <220> <223> ActRIIB signal peptide <400> 49 Met Thr Ala Pro Trp Val Ala Leu Ala Leu Leu Trp Gly Ser Leu Cys 1 5 10 15 Ala Gly <210> 50 <211> 22 <212> PRT <213> Artificial <220> <223> Immunoglobulin light chain signal peptide <400> 50 Met Asp Met Arg Val Pro Ala Gln Leu Leu Gly Leu Leu Leu Leu Trp 1 5 10 15 Leu Arg Gly Ala Arg Cys 20 <210> 51 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 51 Glu Thr Gln Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 52 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 52 Glu Thr Gln Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Val Glu Pro Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 53 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 53 Glu Thr Arg Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Val Glu Pro Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 54 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 54 Glu Thr Gln Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Val Glu Pro Cys Tyr Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 55 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 55 Glu Thr Arg Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 56 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 56 Glu Thr Arg Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 57 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 57 Glu Thr Arg Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 58 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 58 Glu Thr Arg Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 59 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 59 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 60 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 60 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 61 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 61 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 62 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 62 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 63 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 63 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 64 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 64 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 65 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 65 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 66 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 66 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 67 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 67 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 68 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 68 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 69 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 69 Glu Thr Gln Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 70 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 70 Glu Thr Arg Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 71 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 71 Glu Thr Arg Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Val Glu Pro Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 72 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 72 Glu Thr Arg Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Ser Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 73 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 73 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 74 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 74 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 75 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 75 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 76 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 76 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 77 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 77 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 78 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 78 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 79 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 79 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 80 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 80 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Glu Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 81 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 81 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 82 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 82 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Glu Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 83 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 83 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 84 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 84 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 85 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 85 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 86 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 86 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 87 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 87 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 88 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 88 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 89 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 89 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 90 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 90 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 91 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 91 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Glu Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 92 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 92 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Lys Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 93 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 93 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 94 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 94 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Asp Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 95 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 95 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Ser Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 96 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 96 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 97 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 97 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Lys Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Glu Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 98 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 98 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Lys Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Lys Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 99 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 99 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 100 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 100 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Lys Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Lys Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 101 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 101 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Lys Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Glu Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 102 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 102 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Lys Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 103 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 103 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 104 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 104 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Gln Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 105 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 105 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 106 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 106 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Ala Thr Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 107 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 107 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Lys Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 108 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 108 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Lys Glu Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 109 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 109 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 110 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 110 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 111 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 111 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Ser Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 112 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 112 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 113 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 113 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 114 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 114 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Glu Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 115 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 115 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Glu Gly Asp Gln Asp Lys Arg 20 25 30 Leu His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Ile 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Phe Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Lys Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Lys Phe Ser Tyr Phe Pro Gln Met Glu 85 90 95 Val Thr Gln Pro Thr Ser Asn Pro Val Thr Pro Lys Pro Pro 100 105 110 <210> 116 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 116 Glu Thr Gln Glu Cys Leu Phe Phe Asn Ala Asn Trp Glu Lys Asp Arg 1 5 10 15 Thr Asn Gln Thr Gly Val Glu Pro Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Phe Ala Thr Trp Lys Asn Ile Ser Gly Ser Ile Glu Ile 35 40 45 Val Lys Gln Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Thr 50 55 60 Asp Cys Val Glu Lys Lys Asp Ser Pro Glu Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Met Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 117 <211> 110 <212> PRT <213> Artificial <220> <223> Hybrid Human ActRIIB ECD <400> 117 Glu Thr Arg Glu Cys Ile Tyr Tyr Asn Ala Asn Trp Glu Leu Glu Arg 1 5 10 15 Thr Asn Gln Ser Gly Leu Glu Arg Cys Tyr Gly Asp Lys Asp Lys Arg 20 25 30 Arg His Cys Tyr Ala Ser Trp Arg Asn Ser Ser Gly Thr Ile Glu Leu 35 40 45 Val Lys Lys Gly Cys Trp Leu Asp Asp Ile Asn Cys Tyr Asp Arg Gln 50 55 60 Glu Cys Val Ala Thr Lys Glu Asn Pro Gln Val Tyr Phe Cys Cys Cys 65 70 75 80 Glu Gly Asn Phe Cys Asn Glu Arg Phe Thr His Leu Pro Glu Ala Gly 85 90 95 Gly Pro Glu Val Thr Tyr Glu Pro Pro Pro Thr Ala Pro Thr 100 105 110 <210> 118 <211> 12 <212> PRT <213> Artificial <220> <223> Peptide linker <400> 118 Glu Ser Lys Tyr Gly Pro Pro Cys Pro Pro Cys Pro 1 5 10