title: Overexpression system and biochemical profile of CTX-M-3 extended-spectrum beta-lactamase expressed in Escherichia coli.
abstract: An efficient over-expression system was developed for CTX-M-3 extended-spectrum-beta-lactamase. The recombinant enzyme was purified from 1 l of culture to yield 22 mg of pure enzyme. The N-terminal amino acid sequence was determined to be NH2-QTADVQ... Determination of kinetic parameters with the purified CTX-M-3 revealed efficient hydrolysis of penicillins and cephalosporins, while ceftazidime and aztreonam were very poor substrates. Clavulanic acid, sulbactam and especially tazobactam inhibited the CTX-M-3 enzyme.
authors.affiliation: Dipartimento di Scienze e Tecnologie Biomediche, Università di L'Aquila, Cattedra di Biochimica Clinica e Biologia Molecolare Clinica, Loc. Coppito, I-67100 L'Aquila, Italy.
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Perilli
authors.forename: Daniela
authors.initials: D
authors.lastname: Ettorre
authors.forename: Bernardetta
authors.initials: B
authors.lastname: Segatore
authors.forename: Bibiana
authors.initials: B
authors.lastname: Caporale
authors.forename: Francesca
authors.initials: F
authors.lastname: De Santis
authors.forename: Giorgio
authors.initials: G
authors.lastname: Pochetti
authors.forename: Gioconda
authors.initials: G
authors.lastname: Brigante
authors.forename: Fernando
authors.initials: F
authors.lastname: Mazza
authors.forename: Marìa M
authors.initials: MM
authors.lastname: Tavìo
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Amicosante
mesh_terms: D001709:Biotechnology / Q000379:methods; D002439:Cefotaxime / Q000378:metabolism; D016971:Citrobacter freundii / Q000201:enzymology / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D007700:Kinetics; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D015854:Up-Regulation; D001618:beta-Lactamases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D047090:beta-Lactams / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D047090:beta-Lactams; C417271:beta-lactamase CTX-M-3; D001618:beta-Lactamases; D002439:Cefotaxime