title: Binding properties of a peptide derived from beta-lactamase inhibitory protein.
abstract: To overcome the antibiotic resistance mechanism mediated by beta-lactamases, small-molecule beta-lactamase inhibitors, such as clavulanic acid, have been used. This approach, however, has applied selective pressure for mutations that result in beta-lactamases no longer sensitive to beta-lactamase inhibitors. On the basis of the structure of beta-lactamase inhibitor protein (BLIP), novel peptide inhibitors of beta-lactamase have been constructed. BLIP is a 165-amino-acid protein that is a potent inhibitor of TEM-1 beta-lactamase (K(i) = 0.3 nM). The cocrystal structure of TEM-1 beta-lactamase and BLIP indicates that residues 46 to 51 of BLIP make critical interactions with the active site of TEM-1 beta-lactamase. A peptide containing this six-residue region of BLIP was found to retain sufficient binding energy to interact with TEM-1 beta-lactamase. Inhibition assays with the BLIP peptide reveal that, in addition to inhibiting TEM-1 beta-lactamase, the peptide also inhibits a class A beta-lactamase and a class C beta-lactamase that are not inhibited by BLIP. The crystal structures of class A and C beta-lactamases and two penicillin-binding proteins (PBPs) reveal that the enzymes have similar three-dimensional structures in the vicinity of the active site. This similarity suggests that the BLIP peptide inhibitor may have a broad range of activity that can be used to develop novel small-molecule inhibitors of various classes of beta-lactamases and PBPs.
authors.affiliation: Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas 77030-3498, USA.
authors.forename: G W
authors.initials: GW
authors.lastname: Rudgers
authors.forename: W
authors.initials: W
authors.lastname: Huang
authors.forename: T
authors.initials: T
authors.lastname: Palzkill
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D003001:Cloning, Molecular; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial / Q000235:genetics; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D013058:Mass Spectrometry; D008958:Models, Molecular; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism* / Q000494:pharmacology; D011485:Protein Binding; D014961:X-Ray Diffraction; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D010455:Peptides; D065093:beta-Lactamase Inhibitors; C065596:beta-lactamase-inhibitor protein, Streptomyces; D001618:beta-Lactamases