title: Interaction of beta-lactam antibiotics with penicillin-binding proteins from Bacillus megaterium.
abstract: The binding properties of 25 beta-lactam antibiotics to Bacillus megaterium membranes have been studied. The affinities of the antibiotics for the penicillin-binding proteins (PBPs) are also reported. We found that PBP 4 has the highest affinity for nearly all the antibiotics studied whereas PBP 5 has the lowest affinity. Both PBP 4 and PBP 5 appear to be dispensable for the maintenance of bacterial growth and survival and appear to be DD-carboxypeptidases. Only the beta-lactam cefmetazol bound preferentially to PBP 5 and has been used to study the inhibition of DD-carboxypeptidase. Comparative studies with beta-lactam that simultaneously result in (a) binding to PBPs 1 and 3, (b) inhibition of cell growth and (c) lysis, stressed the importance of PBPs 1 and 3 for cell growth and survival.
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology; D001410:Bacillus megaterium / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D011485:Protein Binding; D047090:beta-Lactams / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D047090:beta-Lactams; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase