Interferon β variants and conjugates
The invention relates to a conjugate exhibiting interferon β (IFNB) activity and comprising at least one first non-polypeptide moiety covalently attached to an IFNB polypeptide, the amino acid sequence of which differs from that of wildtype human IFNB in at least one introduced and at least one removed amino acid residue comprising an attachment group for said first non-polypeptide moiety. The first non-polypeptide moiety is e.g. a polymer molecule or a sugar moiety. The conjugate finds particular use in therapy. The invention also relates to a glycosylated variant of a parent IFNB polypeptide comprising at least one in vivo glycosylation site, wherein an amino acid residue of said parent polypeptide located close to said glycosylation site has been modified to obtain the variant polypeptide having an increased glycosylation as compared to the glycosylation of the parent polypeptide.
1. An interferon β polypeptide variant exhibiting interferon β activity, comprising a variant sequence which differs from the wild-type human interferon β sequence SEQ ID NO:2 in no more than 8 amino acid residues, the variant sequence comprising (a) at least one introduced N-glycosylation site comprising two amino acid substitutions relative to SEQ ID NO:2 selected from the group consisting of Q49N+Q51T/S and F111N+R113T/S, and (b) an amino acid substitution at position −1 relative to at least one of the introduced N-glycosylation site(s).
2. The variant according to claim 1 , further comprising at least one naturally occurring N-glycosylation site.
3. The variant according to claim 1 , wherein the variant comprises at least two introduced N-glycosylation sites.
4. The variant according to claim 3 , wherein the at least two introduced N-glycosylation sites comprise substitutions Q49N+Q51T/S and F111N+R113T/S.
5. The variant according to claim 4 , wherein the amino acid substitution at position −1 relative to the introduced N-glycosylation site comprising substitutions Q49N+Q51T/S is selected from the group consisting of Q48F, Q48V, Q48W, and Q48Y and the amino acid substitution at position −1 relative to die introduced N-glycosylation site comprising substitutions F111N+R113T/S is selected from the group consisting of D110F, D110V, D110W, and D110Y.
6. The variant according to claim 5 , further comprising the amino acid substitution C17S.
7. The variant according to claim 1 , further comprising at least one non-polypeptide moiety covalently attached to the variant.
8. The variant according to claim 7 , comprising at least one sugar moiety and at least one polymer molecule.
9. The variant according to claim 8 , wherein a least one of the polymer molecule(s) is covalently attached to a lysine residue of the variant.
10. The variant according to claim 8 , wherein at least one of the polymer molecule(s) is covalently attached to the N-terminus of the variant.
11. The variant according to claim 8 , wherein the polymer molecule comprises a linear polyethylene glycol or a branched polyethylene glycol.
12. A composition comprising the variant of claim 1 or 7 and a diluent, carrier, or excipient.
13. The composition of claim 12 , wherein the diluent, carrier or excipient is a pharmaceutically acceptable diluent, carrier, or excipient.
14. The variant according to claim 1 , wherein the at least one introduced N-glycosylation site comprises substitutions Q49N+Q51T/S relative to SEQ ID NO:2.
15. The variant according to claim 14 , wherein the amino acid substitution at position −1 relative to the at least one introduced N-glycosylation site comprising substitutions Q49N+Q51T/S is selected from the group consisting of Q48F, Q48V, Q48W, and Q48Y.
16. The variant according to claim 1 , wherein the at least one introduced N-glycosylarion site comprises substitutions F111N+R113T/S relative to SEQ ID NO:2.
17. The variant according to claim 16 , wherein the amino acid substitution at position −1 relative to the at least one introduced N-glycosylation site comprising substitutions F111N+R113T/S is selected from the group consisting of D110F, D110V, D110W, and D110Y.
18. The variant according to claim 17 , wherein the amino acid substitution at position −1 relative to the at least one introduced N-glycosylation site comprising substitutions F111N+R113T/S is D110F.
19. The variant according to claim 1 , further comprising the amino acid substitution C17S.