Protein C or activated protein C-like molecules
View Patent ↗The present invention relates to novel conjugates between polypeptide variants of protein C and a non-polypeptide moiety, such as PEG or sugar moieties. In particular, the present invention provides novel protein C conjugates having an increased resistance to inactivation by e.g. human plasma and α 1 -antitrypsin. Consequently, such conjugates have an increased in vivo half-life. Preferred examples include protein C conjugates, wherein at least one additional in vivo N-glycosylation site has been introduced. The conjugates of the invention are useful for treating a variety of diseases, including septic shock.
1. A variant of a parent human protein C polypeptide, the variant comprising a sequence which
(a) differs from the parent human protein C polypeptide sequence SEQ ID NO:4 in 1 to 15 amino acid residues, and
(b) wherein the Asp residue at position 214 is substituted by an amino acid residue having a polar side chain or by an amino acid residue having an opposite charge to Asp,
wherein the variant in activated form exhibits an amidolytic activity.
2. The variant of claim 1 , wherein the activated form exhibits at least 10% of the amidolytic activity of human activated protein C (APC) when tested in the APC Amidolytic Assay.
3. The variant of claim 1 in activated form.
4. The variant of claim 1 , wherein the amino acid residue having a polar side chain is selected from the group consisting of Sew, Thr, Cys, Tyr, Asn and Gln.
5. The variant of claim 4 , comprising the substitution D214N or D214Q.
6. The variant of claim 1 , wherein the amino acid residue having an opposite charge to Asp is selected from the group consisting of Lys and Arg.
7. The variant of claim 6 , comprising the substitution D214K.
8. The variant of claim 1 , wherein the variant in activated form exhibits about 5–75% of the anticoagulant activity of human APC when tested in the APC Clotting Assay.
9. The variant of claim 1 , wherein the variant in activated form exhibits an increased resistance towards inactivation by alpha-1-antitrypsin as compared to human APC.
10. The variant of claim 1 , wherein the variant in activated form exhibits an increased resistance towards inactivation by human plasma as compared to human APC.
11. The variant of claim 1 , wherein rite variant in activated form has an increased functional in vivo half-life or an increased serum half-life as compared to human APC.
12. The variant of claim 1 , wherein the sequence of the variant differs from the parent human protein C polypeptide sequence in 1 to 10 amino acid residues.
13. The variant of claim 1 , which is in vivo glycosylated.
14. The variant of claim 1 , further comprising a substitution in position 251.
15. The variant of claim 14 , comprising the substitution K251D or K251N.
16. A pharmaceutical composition comprising the variant of claim 1 and at least one pharmaceutically acceptable carder or excipient.