title: Effect of beta-lactam antibiotics on in vitro peptidoglycan cross-linking by a particulate fraction from Escherichia coli K-12 and Bacillus megaterium KM.
abstract: The binding constants of several beta-lactam antibiotics towards penicillin-binding components in Escherichia coli K-12 (Spratt, Eur. J. Biochem. 72:341-352, 1977) and the antibiotic concentrations required to inhibit the peptidoglycan transpeptidase of E. coli 50% were compared. Penicillin-binding component 1B may have been the transpeptidase working in vitro. The structure-activity relationships of beta-lactam antibiotics and the mechanisms of action in E. coli and Bacillus megaterium are discussed.
mesh_terms: D001410:Bacillus megaterium / Q000187:drug effects / Q000378:metabolism*; D002511:Cephalosporins / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D010406:Penicillins / Q000494:pharmacology*; D010457:Peptidoglycan / Q000096:biosynthesis*; D010458:Peptidyl Transferases / Q000037:antagonists & inhibitors; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism
chemical_list: D002511:Cephalosporins; D010406:Penicillins; D010457:Peptidoglycan; D010458:Peptidyl Transferases