title: Low-stringency selection of TEM1 for BLIP shows interface plasticity and selection for faster binders.
abstract: Protein-protein interactions occur via well-defined interfaces on the protein surface. Whereas the location of homologous interfaces is conserved, their composition varies, suggesting that multiple solutions may support high-affinity binding. In this study, we examined the plasticity of the interface of TEM1 β-lactamase with its protein inhibitor BLIP by low-stringency selection of a random TEM1 library using yeast surface display. Our results show that most interfacial residues could be mutated without a loss in binding affinity, protein stability, or enzymatic activity, suggesting plasticity in the interface composition supporting high-affinity binding. Interestingly, many of the selected mutations promoted faster association. Further selection for faster binders was achieved by drastically decreasing the library-ligand incubation time to 30 s. Preequilibrium selection as suggested here is a novel methodology for specifically selecting faster-associating protein complexes.
authors.affiliation: Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Ruth
authors.initials: R
authors.lastname: Cohen-Khait
authors.affiliation: Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel gideon.schreiber@weizmann.ac.il.
authors.forename: Gideon
authors.initials: G
authors.lastname: Schreiber
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D015723:Gene Library; D009154:Mutation; D011485:Protein Binding; D011487:Protein Conformation; D025941:Protein Interaction Mapping; D017422:Sequence Analysis, DNA; D020798:Two-Hybrid System Techniques; D065093:beta-Lactamase Inhibitors / Q000737:chemistry*; D001618:beta-Lactamases / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases
keywords: association rate; in vitro evolution; interface plasticity; protein–protein interaction