Anion inhibition studies of the α-carbonic anhydrase from the pathogenic bacterium Vibrio cholerae

Bioorg Med Chem Lett. 2013 Mar 15;23(6):1636-8. doi: 10.1016/j.bmcl.2013.01.084. Epub 2013 Jan 29.


An α-carbonic anhydrase (CA, EC has been recently cloned and characterized in the human pathogenic bacterium Vibrio cholerae, denominated VchCA (Del Prete et al. J. Med. Chem.2012, 55, 10742). This enzyme shows a good catalytic activity for the CO2 hydration reaction, comparable to that of the human (h) isoform hCA I. Many inorganic anions and several small molecules were investigated as VchCA inhibitors. Inorganic anions such as cyanate, cyanide, hydrogen sulfide, hydrogen sulfite, and trithiocarbonate were effective VchCA inhibitors with inhibition constants in the range of 33-88μM. Other effective inhibitors were diethyldithiocarbamate, sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid, with KIs of 7-43μM. Halides (bromide, iodide), bicarbonate and carbonate were much less effective VchCA inhibitors, with KIs in the range of 4.64-28.0mM. The resistance of VchCA to bicarbonate inhibition may represent an evolutionary adaptation of this enzyme to living in an environment rich in this ion, such as the gastrointestinal tract, as bicarbonate is a virulence enhancer of this bacterium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anions / chemistry*
  • Anions / metabolism
  • Carbon Dioxide / metabolism
  • Carbonic Anhydrase Inhibitors / chemistry*
  • Carbonic Anhydrase Inhibitors / metabolism
  • Carbonic Anhydrases / chemistry*
  • Carbonic Anhydrases / metabolism
  • Humans
  • Protein Binding
  • Protein Isoforms / chemistry
  • Protein Isoforms / metabolism
  • Vibrio cholerae / enzymology*


  • Anions
  • Carbonic Anhydrase Inhibitors
  • Protein Isoforms
  • Carbon Dioxide
  • Carbonic Anhydrases