Patent ID: 8258265

Claim:
A fibronectin monobody polypeptide comprising a first fibronectin type III (Fn3) monobody fragment having at least two to five Fn3 beta-strand domains in the Fn3 wild-type arrangement with a loop region linked between each beta-strand domain, and at least one additional complementary fibronectin monobody fragment comprising at least two to five Fn3 beta strand domains in the Fn3 wild-type arrangement with a loop region linked between each beta-strand domain, wherein the loop regions correspond to wild-type Fn3 loop regions, or comprise an AB, BC, CD, DE, or FG loop region sequence that is randomized or varies from a corresponding wild-type Fn3 loop region by deletion of one to all except one amino acid in the loop region, insertion of one to 25 amino acids, and/or replacement of at least one amino acid in the loop region.