68Zn isotope exchange experiments reveal an unusual kinetic lability of the metal ions in the di-zinc form of IMP-1 metallo-beta-lactamase.
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.
Siemann
Stefan
S
Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario P3E 2C6, Canada. ssiemann@laurentian.ca
Badiei
Hamid R
HR
Karanassios
Vassili
V
Viswanatha
Thammaiah
T
Dmitrienko
Gary I
GI
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
D002412:Cations; D015033:Zinc Isotopes; D002104:Cadmium; C409201:beta-lactamase IMP-1; D001618:beta-Lactamases; D015032:Zinc