Patent ID: 7153661

Claim:
A method for obtaining a protein that binds to a target ligand, the method comprising: (a) contacting the target ligand with a fibronectin type III (Fn3) polypeptide monobody binding protein comprising at least two Fn3 beta-strand domain sequences with a loop region sequence linked between each Fn3 beta-strand domain sequence, wherein at least one monobody loop region sequence varies as compared to the wild-type (SEQ ID NO:110, FIG. 2 ) loop region sequence by deletion of two to twelve amino acids in the loop region sequence, insertion of at least two to 25 amino acids, or replacement of at least two amino acids in the loop region sequence, and wherein the polypeptide monobody loop region comprises at least two amino acids and binds to the target ligand to form a binding protein:ligand complex, the contacting being carried out under conditions that allow binding protein:ligand complex formation; and (b) obtaining, from the complex, the binding protein that binds to the ligand.