title: R164H and V240H replacements by site-directed mutagenesis of TEM-149 extended-spectrum β-lactamase: kinetic analysis of TEM-149H240 and TEM-149H164-H240 laboratory mutants.
abstract: Two laboratory mutant forms, TEM-149(H240) and TEM-149(H164-H240), of the TEM-149 extended-spectrum β-lactamase enzyme were constructed by site-directed mutagenesis. TEM-149(H240) and TEM-149(H164-H240) were similar in kinetic behavior, except with respect to benzylpenicillin and ceftazidime. Molecular modeling of the two mutant enzymes demonstrated the role of histidine at position 240 in the reduction of the affinity of the enzyme for ceftazidime.
authors.affiliation: Dipartimento di Scienze Cliniche Applicate e Biotecnologiche, Università degli Studi dell'Aquila, L'Aquila, Italy. perilli@univaq.it
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Perilli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Celenza
authors.forename: Paola Sandra
authors.initials: PS
authors.lastname: Mercuri
authors.forename: Moreno
authors.initials: M
authors.lastname: Galleni
authors.forename: Cristina
authors.initials: C
authors.lastname: Pellegrini
authors.forename: Bernardetta
authors.initials: B
authors.lastname: Segatore
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Amicosante
mesh_terms: D019943:Amino Acid Substitution; D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology; D055162:Biocatalysis; D002442:Ceftazidime / Q000378:metabolism* / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D021902:Enterobacter aerogenes / Q000187:drug effects / Q000201:enzymology; D004926:Escherichia coli / Q000187:drug effects; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D016297:Mutagenesis, Site-Directed; D010400:Penicillin G / Q000378:metabolism* / Q000494:pharmacology; D012706:Serratia marcescens / Q000187:drug effects / Q000201:enzymology; D001618:beta-Lactamases / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D002442:Ceftazidime; D001618:beta-Lactamases; D010400:Penicillin G