title: Biochemical characterisation of the CTX-M-14 beta-lactamase.
abstract: Cefotaxime-resistant Escherichia coli TUM1121 was isolated from an abscess of an 83-year-old patient. The CTX-M-14 gene was located on a 70 kb plasmid. The enzyme was purified and its activity was analysed. CTX-M-14 was poorly active against ceftazidime and aztreonam. Aztreonam behaved as a competitive inhibitor. Among the tested suicide substrates for class A beta-lactamases, sulbactam was a rather good substrate. Tazobactam and clavulanic acid behaved as inactivators. The interactions between clavulanic acid and CTX-M-14 were characterised by progressive inactivation of the beta-lactamase. Carbapenems such as imipenem, meropenem or doripenem did not behave as inactivators of CTX-M-14, however very small k(cat) values were observed. This result shows that CTX-M-14 is able to hydrolyse carbapenems.
authors.affiliation: Centre for Protein Engineering, University of Liège, B6 Institute of Chemistry, Sart Tilman, B4000 Liège, Belgium. yoishii@med.toho-u.ac.jp
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ishii
authors.forename: Moreno
authors.initials: M
authors.lastname: Galleni
authors.forename: Ling
authors.initials: L
authors.lastname: Ma
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Frère
authors.forename: Keizo
authors.initials: K
authors.lastname: Yamaguchi
mesh_terms: D003001:Cloning, Molecular; D007700:Kinetics; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: C456080:beta-lactamase CTX-M-14; D001618:beta-Lactamases