Carbonic anhydrase inhibitors: The β-carbonic anhydrase from Helicobacter pylori is a new target for sulfonamide and sulfamate inhibitors

DNA clones for the β-class carbonic anhydrase (CA, EC 4.2.1.1) of Helicobactor pylori (hpβCA) were obtained. A recombinant hpβCA protein lacking the N-terminal 15-amino acid residues was produced and purified, representing a catalytically efficient CA. hpβCA was strongly inhibited (KIs in the range of 24–45 nM) by many sulfonamides/sulfamates, among which acetazolamide, ethoxzolamide, topiramate, and sulpiride, all clinically used drugs. The dual inhibition of α- and/or β-class CAs of H. pylori might represent a useful alternative for the management of gastritis/gastric ulcers, as well as gastric cancer. This is also the first study showing that a bacterial β-CA can be a drug target.