The effect of zinc ions on the activity of metallo-beta-lactamases of Bacteroides fragilis.
The zinc supplement required to achieve the maximum activity of metallo-beta-lactamases from 12 Bacteroides fragilis isolates was investigated. Changes in absorbance of imipenem in a spectrophotometric assay with crude cell extracts were performed in the presence and absence of various concentrations of zinc sulphate. The greatest degree of imipenem hydrolysis was seen with the addition of between 50 and 500 microM zinc sulphate, and the degree of stimulation of enzyme activity in the strains tested varied six-fold. Increasing the zinc sulphate concentration resulted in inhibition of hydrolysis with extracts of low enzymic activity. These findings indicate the importance of determining the optimal zinc concentration for each strain tested in kinetic studies of metallo-beta-lactamases.
Edwards
R
R
Division of Microbiology, University Hospital, Queen's Medical Centre, Nottingham.
Hashmi
P S
PS
Greenwood
D
D
D001441:Bacteroides fragilis / Q000187:drug effects / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D006868:Hydrolysis; D015378:Imipenem / Q000378:metabolism*; D019287:Zinc Sulfate / Q000494:pharmacology*; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism*
D065093:beta-Lactamase Inhibitors; D015378:Imipenem; D019287:Zinc Sulfate; D001618:beta-Lactamases