Universal fibronectin type III binding-domain libraries
Fibronectin Type III (FN3) polypeptide libraries are described, along with their use in identifying fibronectin-type binding peptides having high binding affinities, e.g., greater than 300 nM, for VEGFR2 or Axl proteins.
1. A VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) binding peptide having a K d dissociation constant equal to or greater than 300 nM and having a sequence selected from SEQ ID NOS: 223-331.
2. The VEGFR2 binding peptide of claim 1 , which has a sequence selected from the group consisting of SEQ ID NOS: 273, 226, 295, 275, 270, 274, 229, 227, 223 and 248.
3. The VEGFR2 binding peptide of claim 2 , wherein the dissociation constant K d is equal to or greater than 50 nM.
4. The VEGFR2 binding peptide of claim 3 , wherein the dissociation constant K d is equal to or greater than 5 nM.
5. The VEGFR2 binding peptide of claim 2 , which has the sequence selected from the group consisting of SEQ ID NOS: 273, 226, 295, 275, and 270.
6. The VEGFR2 binding peptide of claim 5 , wherein the peptide has the sequence SEQ ID NOS: 273.