title: Ultrastructural localization of penicillin-binding sites in Staphylococcus aureus using penicillin G-BSA-gold.
abstract: Penicillin G (PcG) conjugated to bovine serum albumin (BSA) was found to retain antibacterial activity against Staphylococcus aureus as judged by growth inhibition and by ultrastructural analyses of the PcG-BSA-treated bacterium. Using the PcG-BSA conjugated to colloidal gold, binding sites of PcG were localized in S. aureus with electron microscopy using a postembedding labeling technique. To our surprise, labeling was observed both on the cell wall and in the cytoplasm of S. aureus. A part of the labeling observed may be attributed to penicillin-binding proteins (PBPs) or their precursors. Also there may be other molecules which bind with PcG in the cell wall and cytoplasm of S. aureus.
authors.affiliation: Laboratory of Electron Microscopy, Kyoto Prefectural University of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Morioka
authors.forename: M
authors.initials: M
authors.lastname: Tachibana
mesh_terms: D001426:Bacterial Proteins; D001665:Binding Sites; D002352:Carrier Proteins / Q000302:isolation & purification*; D004305:Dose-Response Relationship, Drug; D006046:Gold; D006602:Hexosyltransferases; D006651:Histocytochemistry; D008854:Microscopy, Electron; D002267:Muramoylpentapeptide Carboxypeptidase / Q000302:isolation & purification*; D010400:Penicillin G / Q000031:analogs & derivatives / Q000378:metabolism*; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D012710:Serum Albumin, Bovine; D013194:Staining and Labeling; D013211:Staphylococcus aureus / Q000648:ultrastructure*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D012710:Serum Albumin, Bovine; D006046:Gold; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D010400:Penicillin G