title: Identification of two penicillin-binding multienzyme complexes in Haemophilus influenzae.
abstract: Dansyl-labeled penicillin, reversed-phase chromatography, and peptide mapping have been used to detect, separate, and study penicillin-binding proteins (PBPs) and PBP multienzyme complexes of H. influenzae. The cross-linking of proteins in the multienzyme complex was accomplished with the aid of cyanogen, a salt-bridge specific cross-linking agent. The chromatographic profile of the PBPs clearly showed a dramatic change in the number and identity of peaks after treatment of the bacterial cells with cyanogen. The disappearance of all seven peaks corresponding to the PBPs was accompanied by the emergence of two new peaks with molecular weights between 400 kDa and 600 kDa. The results hint at the existence of two penicillin-binding multienzyme complexes, each containing subunits that interact via salt-bridges. Chromatographic active site peptide mapping of PBPs and PBP complexes was used to determine the identity of PBPs involved in each complex. It is postulated that one multienzyme complex containing PBP 2 may be involved in cell elongation while the other complex containing PBP 3 may be responsible for cell division.
authors.affiliation: Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, 45221, USA.
authors.forename: A
authors.initials: A
authors.lastname: Alaedini
authors.forename: R A
authors.initials: RA
authors.lastname: Day
mesh_terms: D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000302:isolation & purification* / Q000378:metabolism; D005456:Fluorescent Dyes; D006193:Haemophilus influenzae / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D006602:Hexosyltransferases; D008970:Molecular Weight; D009097:Multienzyme Complexes / Q000302:isolation & purification* / Q000378:metabolism; D002267:Muramoylpentapeptide Carboxypeptidase / Q000302:isolation & purification* / Q000378:metabolism; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism; D046915:Penicillin-Binding Proteins; D010449:Peptide Mapping; D010453:Peptide Synthases / Q000378:metabolism; D010458:Peptidyl Transferases
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D005456:Fluorescent Dyes; D009097:Multienzyme Complexes; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D009238:N-Acetylmuramoyl-L-alanine Amidase; D010453:Peptide Synthases; C021814:murein synthetase