Binding of beta-lactam antibiotics to penicillin-binding proteins of Staphylococcus aureus and Streptococcus faecalis: relation to antibacterial activity.
The binding of 14 structurally diverse beta-lactam antibiotics to penicillin-binding proteins of Staphylococcus aureus and Streptococcus faecalis was studied, and the results were examined in the context of the antibacterial activity of the compounds. Penicillin-binding proteins 1 (molecular weight, 87,000) and 3 (molecular weight, 75,000) of S. aureus and penicillin-binding proteins 1 (molecular weight, 105,000) and 3 (molecular weight, 79,000) of S. faecalis bound beta-lactam antibiotics at concentrations comparable to minimum inhibitory concentrations and might therefore be essential. The low affinity of S. faecalis penicillin-binding proteins, relative to that of S. aureus penicillin-binding proteins, toward most beta-lactam antibiotics is probably responsible for the resistance of the former organism to most of these compounds.
D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000378:metabolism*; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000378:metabolism*; D010458:Peptidyl Transferases; D011485:Protein Binding; D013211:Staphylococcus aureus / Q000378:metabolism*; D047090:beta-Lactams / Q000378:metabolism / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D047090:beta-Lactams; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase