Modified vitamin K. dependent polypeptides
The invention provides vitamin K-dependent polypeptides with enhanced membrane binding affinity. These polypeptides can be used to modulate clot formation in mammals. Methods of modulating clot formation in mammals are also described.
1. An isolated nucleic acid comprising a nucleic acid sequence encoding a vitamin K-dependent polypeptide that increases clot formation comprising a modified GLA domain that enhances membrane binding affinity of said polypeptide relative to a corresponding native vitamin K-dependent polypeptide, wherein said modified GLA domain comprises the sequence of SEQ ID NO: 3 or SEQ ID NO: 4 with two to five amino acid substitutions, which include a glutamine residue substituted at amino acid position 10 and an amino acid substitution at one or more amino acid positions selected from positions 28, 32, 33, 34.
2. A vector comprising the nucleic acid of claim 1 .
3. A host cell comprising the vector of claim 2 .
4. An isolated nucleic acid comprising a nucleic acid sequence encoding a mutant Factor VII or VIIa polypeptide that increases clot formation, wherein said polypeptide comprises a modified GLA domain that enhances membrane binding affinity of said polypeptide relative to a corresponding native Factor VII or Factor VIIa polypeptide, said modified GLA domain comprising two to five amino acid substitutions, which include a glutamine residue substituted at amino acid position 10 and an amino acid substitution at one or more amino acid positions selected from positions 28, 32, 33, and 34 of SEQ ID NO:3 or SEQ ID NO:4.
5. A vector comprising a nucleic acid of claim 4 .
6. A host cell comprising the vector of claim 5 .
7. A method for producing a vitamin K-dependent polypeptide comprising a modified GLA domain that enhances membrane binding affinity of said polypeptide relative to a corresponding native vitamin K-dependent polypeptide, wherein said modified GLA domain comprises the sequence of SEQ ID NO: 3 or SEQ ID NO: 4 with two to five amino acid substitutions, which include a glutamine residue substituted at amino acid position 10 and an amino acid substitution at one or more amino acid positions selected from positions 28, 32, 33, and 34 of SEQ ID NO: 3 or SEQ ID NO: 4, the method comprising (a) culturing a host cell of claim 3 under conditions which permit expression of the polypeptide, and (b) recovering the polypeptide.