title: Kinetic and spectroscopic characterization of native and metal-substituted beta-lactamase from Aeromonas hydrophila AE036.
abstract: Two metal ion binding sites are conserved in metallo-beta-lactamase from Aeromonas hydrophila. The ligands of a first zinc ion bound with picomolar dissociation constant were identified by EXAFS spectroscopy as one Cys, two His and one additional N/O donor. Sulfur-to-metal charge transfer bands are observed for all mono- and di-metal species substituted with Cu(II) or Co(II) due to ligation of the single conserved cysteine residue. Binding of a second metal ion results in non-competitive inhibition which might be explained by an alternative kinetic mechanism. A possible partition of metal ions between the two binding sites is discussed.
authors.affiliation: Fachrichtung 12.4 Biochemie, Universität des Saarlandes, D-66041, Saarbrücken, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Hernandez Valladares
authors.forename: M
authors.initials: M
authors.lastname: Kiefer
authors.forename: U
authors.initials: U
authors.lastname: Heinz
authors.forename: R P
authors.initials: RP
authors.lastname: Soto
authors.forename: W
authors.initials: W
authors.lastname: Meyer-Klaucke
authors.forename: H F
authors.initials: HF
authors.lastname: Nolting
authors.forename: M
authors.initials: M
authors.lastname: Zeppezauer
authors.forename: M
authors.initials: M
authors.lastname: Galleni
authors.forename: J M
authors.initials: JM
authors.lastname: Frère
authors.forename: G M
authors.initials: GM
authors.lastname: Rossolini
authors.forename: G
authors.initials: G
authors.lastname: Amicosante
authors.forename: H W
authors.initials: HW
authors.lastname: Adolph
mesh_terms: D016980:Aeromonas hydrophila / Q000201:enzymology* / Q000235:genetics; D001665:Binding Sites; D003035:Cobalt / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D015378:Imipenem / Q000737:chemistry; D007700:Kinetics; D013057:Spectrum Analysis; D015032:Zinc / Q000737:chemistry; D001618:beta-Lactamases / Q000737:chemistry*
chemical_list: D003035:Cobalt; D015378:Imipenem; D003300:Copper; D001618:beta-Lactamases; D015032:Zinc