Variant activin IIB receptor
The present invention provides variant activin IIB soluble receptor polypeptides and proteins capable of binding and inhibiting the activities of activin A, myostatin, or GDF-11. The present invention also provides polynucleotides, vectors and host cells capable of producing the variant polypeptides and proteins. Compositions and methods for treating muscle-wasting and other diseases and disorders are also provided.
1. An isolated protein comprising a variant activin IIB receptor (vActRIIB) polypeptide wherein the polypeptide is selected from the group consisting of:
(a) a polypeptide comprising the amino acid sequence set forth in SEQ ID NO: 18, wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E;
(b) a polypeptide comprising the amino acid sequence set forth in amino acids 19 through 134 of SEQ ID NO: 18, wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E;
(c) a polypeptide comprising the amino acid sequence set forth in amino acids 23 through 134 of SEQ ID NO: 18, wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E;
(d) a polypeptide comprising the amino acid sequence set forth in amino acids 25 through 134 of SEQ ID NO: 18, wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E; and
(e) a polypeptide having at least 95% identity to any one of (a) through (d), wherein the polypeptide comprises an amino acid substitution at the position corresponding to position 28 of SEQ ID NO:18, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E, and wherein the polypeptide is capable of binding myostatin, activin A, or GDF-11.
2. The protein of claim 1 , wherein the substitution at position 28 of the vActRIIB polypeptide is selected from the group of amino acids consisting of A, W and Y for E.
3. The protein of claim 1 , wherein the substitution at position 28 of the vActRIIB polypeptide is W for E.
4. The protein of claim 1 , wherein the isolated protein further comprises the sequence set forth in SEQ ID NO:79.
5. The pharmaceutical composition of claim 1 , wherein the isolated protein further comprises the sequence set forth in SEQ ID NO:80.
6. The protein of claim 1 , wherein the polypeptide sequence has at least 95% identity to the amino acid sequence set forth at amino acids 25 through 134 of SEQ ID NO: 18, and wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E, and wherein the polypeptide is capable of binding myostatin, activin A, or GDF-11.
7. The protein of claim 1 , wherein the polypeptide sequence has at least 95% identity to the amino acid sequence set forth at amino acids 25 through 134 of SEQ ID NO: 18, wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is W for E, and wherein the isolated protein further comprises an Fc domain linked to vActRIIB polypeptide via a linker.
8. The protein of claim 1 , wherein the polypeptide sequence has at least 99% identity to the amino acid sequence set forth at amino acids 25 through 134 of SEQ ID NO: 18, wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is W for E, and wherein the isolated protein further comprises a human Fc domain (SEQ ID NO:80) linked to vActRIIB polypeptide via a peptide linker (SEQ ID NO:79).
9. A homodimer comprising the protein of claim 8 .
10. A pharmaceutical composition comprising the homodimer of claim 9 and an excipient.
11. A pharmaceutical composition comprising the protein of claim 8 and an excipient.
12. The isolated protein of claim 1 , wherein the polypeptide is fused to at least one heterologous polypeptide.
13. A dimer comprising the protein of claim 1 .
14. The dimer of claim 13 , wherein the dimer is a homodimer.
15. A pharmaceutical composition comprising the dimer of claim 14 and an excipient.
16. A pharmaceutical composition comprising the dimer of claim 13 and an excipient.
17. A pharmaceutical composition comprising the protein of claim 1 and an excipient.
18. The protein of claim 1 , wherein the polypeptide sequence has at least 97% identity to the amino acid sequence set forth at amino acids 25 through 134 of SEQ ID NO: 18, and wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E, and wherein the polypeptide is capable of binding myostatin, activin A, or GDF-11.
19. The protein of claim 1 , wherein the polypeptide sequence has at least 98% identity to the amino acid sequence set forth at amino acids 25 through 134 of SEQ ID NO: 18, and wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E, and wherein the polypeptide is capable of binding myostatin, activin A, or GDF-11.
20. The protein of claim 1 , wherein the polypeptide sequence has at least 99% identity to the amino acid sequence set forth at amino acids 25 through 134 of SEQ ID NO: 18, and wherein the polypeptide comprises an amino acid substitution at position 28, wherein the substitution at position 28 is A, W, Y, F, Q, V, I, L, M, K, or H for E, and wherein the polypeptide is capable of binding myostatin, activin A, or GDF-11v.