<p>An evidence describes the source of an annotation, e.g. an experiment that has been published in the scientific literature, an orthologous protein, a record from another database, etc.</p>
A sulfonamide derivative of the antihelmintic drug thiabendazole was prepared and investigated for inhibition of the zinc enzyme carbonic anhydrase CA (EC 126.96.36.199). Mammalian isoforms CA I-XIV and the nematode enzyme of Caenorhabditis elegans CAH-4b were included in this study. Thiabendazole-5-sulfonamide was a very effective inhibitor of CAH-4b and CA IX (K(I)s of 6.4-9.5nm) and also inhibited effectively isozymes CA I, II, IV-VII, and XII, with K(I)s in the range of 17.8-73.2nM. The high resolution X-ray crystal structure of its adduct with isozyme II evidenced the structural elements responsible for this potent inhibitory activity.