title: 68Zn isotope exchange experiments reveal an unusual kinetic lability of the metal ions in the di-zinc form of IMP-1 metallo-beta-lactamase.
abstract: The apparently paradoxical behaviour of facile exchange (kinetic lability) of tightly bound (thermodynamic stability) zinc ions in the enzyme IMP-1 metallo-beta-lactamase with Zn-68 and cadmium ions, as indicated by in-torch vaporization inductively-coupled plasma mass spectrometry (ITV-ICP-MS) and electrospray-ionization mass spectrometry (ESI-MS), is consistent with the involvement of a third metal ion in promoting Lewis acid/base type exchange processes.
authors.affiliation: Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario P3E 2C6, Canada. ssiemann@laurentian.ca
authors.forename: Stefan
authors.initials: S
authors.lastname: Siemann
authors.forename: Hamid R
authors.initials: HR
authors.lastname: Badiei
authors.forename: Vassili
authors.initials: V
authors.lastname: Karanassios
authors.forename: Thammaiah
authors.initials: T
authors.lastname: Viswanatha
authors.forename: Gary I
authors.initials: GI
authors.lastname: Dmitrienko
mesh_terms: D002104:Cadmium / Q000737:chemistry* / Q000378:metabolism; D002412:Cations; D007700:Kinetics; D021241:Spectrometry, Mass, Electrospray Ionization; D015032:Zinc / Q000737:chemistry* / Q000378:metabolism; D015033:Zinc Isotopes / Q000737:chemistry* / Q000378:metabolism; D001618:beta-Lactamases / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002412:Cations; D015033:Zinc Isotopes; D002104:Cadmium; C409201:beta-lactamase IMP-1; D001618:beta-Lactamases; D015032:Zinc