Streptomyces K15 DD-peptidase-catalysed reactions with suicide beta-lactam carbonyl donors

• Published in: Biochemical journal 1986-04, Vol.235 (1), p.177-182
• Main Authors: Leyh-Bouille, M, Nguyen-Distèche, M, Pirlot, S, Veithen, A, Bourguignon, C, Ghuysen, J M
• Format: Article
• Language: English
• Subjects: Acylation; Anti-Bacterial Agents - metabolism; benzylpenicillin; beta -lactam antibiotics; Biochemistry, biophysics & molecular biology; Biochimie, biophysique & biologie moléculaire; Carboxypeptidases - metabolism; cefoxitin; Cefoxitin - metabolism; Kinetics; Life sciences; Microbiologie; Microbiology; Muramoylpentapeptide Carboxypeptidase - metabolism; Oligopeptides - metabolism; Penicillin G - metabolism; peptidase; Sciences du vivant; Streptomyces; Streptomyces - enzymology; Structure-Activity Relationship; Substrate Specificity
• ISSN: 0264-6021; 1470-8728; 1470-8728
• DOI: 10.1042/bj2350177

The values of the kinetic parameters that govern the interactions between the Streptomyces K15 DD-peptidase and beta-lactam compounds were determined by measuring the inactivating effect that these compounds exert on the transpeptidase activity of the enzyme and, in the case of [14C]benzylpenicillin and [14C]cefoxitin, by measuring the amounts of acyl-enzyme formed during the reaction. K15 DD-peptidase binds benzylpenicillin or cefoxitin at a molar ratio of 1:1. Benzylpenicilloate is the major product released during breakdown of the acyl-enzyme formed with benzylpenicillin. Benzylpenicillin is not a better acylating agent than the amide Ac2-L-Lys-D-Ala-D-Ala and ester Ac2-L-Lys-D-Ala-D-lactatecarbonyl-donor substrates. beta-Lactam compounds possessing a methoxy group on the alpha-face of the molecule show high inactivating potency.