Patent ID: 7544477
Filing Date: 2009-06-09
Classification: C07K,C12N,G01N

Abstract:
1. A polypeptide consisting essentially of: a circularly permutated TEM-1 β-lactamase protein, joined at the original amino and carboxy termini, having an N-terminal portion with a new C-terminus and a C-terminal portion with a new N-terminus, a first interactor domain, and a second interactor domain; wherein the first interactor domain is fused through the new N-terminus of the C-terminal portion, and the second interactor domain is fused through the new C-terminus of the N-terminal portion; and wherein the new N-terminus and the new C-terminus are located within a solvent exposed loop between amino acid residues Thr 195 and Ala 202 (residues 170-177 of SEQ ID NO:2); and wherein the first interactor domain is selected from the group consisting of an antibody, an antigen, a first monomer of a hetero-dimerizing helix, a second monomer of a hetero-dimerizing helix, a receptor, a member of an expressed sequence library, and a member of a constrained peptide library; and wherein the second interactor domain is selected from the group consisting of an antibody, an antigen, a first monomer of a hetero-dimerizing helix, a second monomer of a hetero-dimerizing helix, a receptor, a member of an expressed sequence library, and a member of a constrained peptide library; wherein the circularly permutated TEM-1 β-lactamase protein is functionally reconstituted only upon binding of said first interactor domain to said second interactor domain, optionally through a ligand.