title: An additional ionic bond suggested by molecular modelling of TEM-2 might induce a slight discrepancy between catalytic properties of TEM-1 and TEM-2 beta-lactamases.
abstract: The plasmid-mediated TEM-1 and TEM-2 beta-lactamases are the most commonly encountered among Gram-negative bacteria. They belong to molecular class A, and differ by one amino acid at position 39:TEM-1 have a glutamine and TEM-2 a lysine. Kinetic parameters (kcat and Km) and catalytic efficiency (kcat/Km) of TEM-1 and TEM-2 beta-lactamases are slightly, but significantly different. For all antibiotics except methicillin and cefazolin, the catalytic efficiency values of TEM-2 are clearly greater than that of TEM-1. Molecular modelling of TEM-2, when compared to that of TEM-1, showed an additional ionic bond between Lys-39 and Glu-281.
authors.affiliation: Muséum National Histoire Naturelle, CNRS URA 401, Paris, France.
authors.forename: E B
authors.initials: EB
authors.lastname: Chaïbi
authors.forename: S
authors.initials: S
authors.lastname: Farzaneh
authors.forename: J
authors.initials: J
authors.lastname: Péduzzi
authors.forename: M
authors.initials: M
authors.lastname: Barthélémy
authors.forename: R
authors.initials: R
authors.lastname: Labia
mesh_terms: D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D006090:Gram-Negative Bacteria / Q000201:enzymology / Q000235:genetics; D007700:Kinetics; D008958:Models, Molecular; D015394:Molecular Structure; D011487:Protein Conformation; D001618:beta-Lactamases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001618:beta-Lactamases; C034413:beta-lactamase TEM-1; C056342:beta-lactamase TEM-2