Patent ID: 7063943

Claim:
A method of producing a specific binding pair member, which method comprises: expressing in recombinant host cells a library of nucleic acid sequences encoding a genetically diverse population of polypeptides, which library of nucleic acid sequences is provided by mutating nucleic acid encoding a specific binding pair member which comprises an enzyme or fragment thereof wherein said enzyme or fragment thereof is a non-immunoglobulin protein, which enzyme or fragment thereof is able to bind a ligand of said enzyme, has enzymatic activity when displayed at the surface of filamentous bacteriophage particles, as measured in an enzymatic assay, and is at least 100 amino acids, wherein said polypeptides encoded by the library are displayed at the surface of filamentous bacteriophage particles, and wherein genetic material of each filamentous bacteriophage particle displaying a polypeptide includes nucleic acid encoding the polypeptide displayed on that particle.