Binding molecules for human factor VIII and factor VIII-like proteins
It is an object of the present invention to provide novel binding molecules for factor VIII and factor VIII-like proteins. Preferred binding molecules of the present invention exhibit not only distinct characteristics for binding of the target factor VIII polypeptides but also specific and desirable characteristics for release (elution) of the target polypeptides. Especially preferred binding molecules according to the invention are short polypeptide sequences, characterized by a stable loop structure.
1. A polypeptide comprising the amino acid sequence X 1 -X 2 -Cys-Ser-Trp-X 3 -X 4 -Pro-Cys-X 5 -X 6 (SEQ ID NO: 55), wherein:
X 1 is Arg or Phe;
X 2 is Leu or Gly;
X 3 is Phe;
X 4 is Ser or Phe;
X 5 is Ser or Pro; and
X 6 is Ala or Phe,
such that the polypeptide binds factor VIII.
2. The polypeptide of claim 1 , wherein X 1 is Arg, X 2 is Leu, X 4 is Ser, X 5 is Ser and X 6 is Ala.
3. The polypeptide of claim 1 , wherein a terminal amino acid residue comprises a chemical modification.
4. The polypeptide of claim 3 , wherein the carboxyl terminus comprises a chemical modification.
5. The polypeptide of claim 4 , wherein the chemical modification comprises a hydrazide functional group.
6. The polypeptide of claim 3 , wherein the amino terminus has a chemical modification.
7. The polypeptide of claim 6 , wherein the chemical modification is an acetylation.
8. A composition comprising a polypeptide comprising the amino acid sequence X 1 -X 2 -Cys-Ser-Trp-X 3 -X 4 -Pro-Cys-X 5 -X 6 (SEQ ID NO: 55), wherein:
X 1 is Arg or Phe;
X 2 is Leu or Gly;
X 3 is Phe;
X 4 is Ser or Phe;
X 5 is Ser or Pro; and
X 6 is Ala or Phe,
and wherein the polypeptide can bind factor VIII and the polypeptide is attached to a solid support matrix.
9. The composition of claim 8 wherein the polypeptide is attached to the solid support matrix via a covalent or non-covalent linkage.
10. The composition of claim 9 , wherein the solid support matrix is selected from the group consisting of: sepharose, agarose and cellulose.
11. A recombinant bacteriophage expressing exogenous DNA encoding a polypeptide, the polypeptide comprising the amino acid sequence X 1 -X 2 -Cys-Ser-Trp-X 3 -X 4 -Pro-Cys-X 5 -X 6 (SEQ ID NO: 55), wherein:
X 1 is Arg or Phe;
X 2 is Leu or Gly;
X 3 is Phe;
X 4 is Ser or Phe;
X 5 is Ser or Pro; and
X 6 is Ala or Phe;
such that the polypeptide binds factor VIII.
12. The recombinant bacteriophage of claim 11 , wherein X 1 is Arg, X 2 is Leu, X 4 is Ser, X 5 is Ser and X 6 is Ala.