Variants of RANKL protein
The present invention relates to novel, soluble, recombinant RANKL (Receptor Activator of Nuclear Factor—κB Ligand) variant proteins which may be expressed solubly in E. coli , variants that have substantially reduced binding to OPG, variants that act as RANKL antagonists, and methods for generating the same.
1. A variant RANKL protein comprising an amino acid modification at C0221S and I247E and at least one further amino acid modification selected from the group consisting of: R223M, R223E, R223Q, H225T, H225N, H225E, H225R, E226Q, E226D, E226R, Q237T, Q237K, Q237E, E269R, E269T, E269Q and E269K in SEQ ID NO:1 when numbered as amino acids 68-317 corresponding to the numbering of the full-length wild-type human RANKL sequence.
2. A variant RANKL protein according to claim 1 , wherein said variant RANKL protein further comprises at least one set of amino acid modifications selected from the group consisting of:
a) one of H225T, H225N, H225E, or H225R and one of E269R, E269T, E269Q or E269K; or
b) one of H225T, H225N, H225E, or H225R and one of E226Q, E226D, or E226R.
3. A variant RANKL protein according to claim 1 , wherein said variant RANKL protein comprises amino acid modifications at C221S and I247E and at least one further set of amino acid modifications selected from the group consisting of: a) H225E and E269K, or b) H225R and E269K.
4. A variant RANKL protein according to claim 1 , wherein said variant RANKL protein comprises amino acid modifications at C221S and I247E and at least one further amino acid modification selected from the group consisting of: R223Q, E226R, Q237K, E269T, and E269Q.
5. A variant RANKL protein according to claim 1 , wherein said variant RANKL protein further comprises at least one amino acid modification selected from the group consisting of: a) R223M, R223E, or R230Q; b) Q237T, Q237K, or Q237E; c) H225T, H225N, H225E, or H225R; d) E269R, E269T, E269Q or E269K, and e) E226Q, E226D, or E226R.
6. A variant RANKL protein according to claim 5 , wherein said variant RANKL protein further comprises amino acid modifications at one of H225T, H225N, H225E, or H225R and one of E269R, E269T, E269Q or E269K.
7. A variant RANKL protein according to claim 5 , wherein said variant RANKL protein comprises amino acid modifications at C221S and I247E and at least one further set of amino acid modification at H225R and E269K.
8. A variant RANKL protein according to claim 1 , wherein said variant RANKL protein further comprises at least one modification selected from the group consisting of: H225T, H225N, H225E, H225R, E226Q, E226D, E226R, E269R, E269T, E269Q and E269K.
9. A variant RANKL protein according to claim 8 , wherein said variant RANKL protein comprises amino acid modifications at C221S and I247E and at least one further amino acid modification or set of amino acid modifications selected from the group consisting of: H225T, H225N, H225E, H225R, E226Q, E269R, E269K, (H225E and E269K), and (H225R and E269K).
10. A variant RANKL protein according to claim 1 , wherein said variant RANKL protein comprises amino acid modifications C221S and I247E and at least one further amino acid modification selected from the group consisting of: R223M, R223E, H225T, H225N, H225E, H225R, E226Q, E226D, Q237K, Q237E, E269R, E269T, E269Q, and E269K.
11. A variant RANKL protein according to claim 1 , wherein said variant RANKL protein comprises amino acid modifications C221S and I247E and at least one further amino acid modification selected from the group consisting of: R223M, R223E, R223Q, E226R, Q237K, E269T, and E269Q.
12. A variant RANKL protein according to claim 1 , wherein said variant protein is chemically modified.
13. A variant RANKL protein according to claim 12 , wherein said chemical modification is selected from the group consisting of: PEGylation and glycosylation.
14. A pharmaceutical composition comprising a variant RANKL protein according to claim 1 and a pharmaceutical carrier.