Comparison of Verona Integron-Borne Metallo-β-Lactamase (VIM) Variants Reveals Differences in Stability and Inhibition Profiles
Antimicrobial Agents and Chemotherapy March 2016 V.60 N.3 P.1377-1384
Anne Makena, Azer Ö. Düzgün, Jürgen Brem, Michael A. McDonough, Anna M. Rydzik, Martine I. Abboud, Ayşegül Saral, Ayşegül Ç. Çiçek, Cemal Sandalli, and Christopher J. Schofield
aChemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
bDepartment of Genetics and Bioengineering, Gümüşhane University, Gümüşhane, Turkey
cDepartment of Biology, Coruh University, Artvin, Turkey
dDepartment of Medical Microbiology, Recep Tayyip Erdoğan University, Rize, Turkey
eDepartment of Biology, Recep Tayyip Erdoğan University, Rize, Turkey
Metallo-β-lactamases (MBLs) are of increasing clinical significance; the development of clinically useful MBL inhibitors is challenged by the rapid evolution of variant MBLs.
The Verona integron-borne metallo-β-lactamase (VIM) enzymes are among the most widely distributed MBLs, with >40 VIM variants having been reported. We report on the crystallographic analysis of VIM-5 and comparison of biochemical and biophysical properties of VIM-1, VIM-2, VIM-4, VIM-5, and VIM-38.
Recombinant VIM variants were produced and purified, and their secondary structure and thermal stabilities were investigated by circular dichroism analyses. Steady-state kinetic analyses with a representative panel of β-lactam substrates were carried out to compare the catalytic efficiencies of the VIM variants.
Furthermore, a set of metalloenzyme inhibitors were screened to compare their effects on the different VIM variants. The results reveal only small variations in the kinetic parameters of the VIM variants but substantial differences in their thermal stabilities and inhibition profiles.
Overall, these results support the proposal that protein stability may be a factor in MBL evolution and highlight the importance of screening MBL variants during inhibitor development programs.