Exploration of the binding mode of indanesulfonamides as selective inhibitors of human carbonic anhydrase type VII by targeting Lys91

Convulsions are common neurological disorders in clinical medicine and are triggered by several mechanisms. The enhancement of neuronal excitability can be related, among other factors, to GABAergic depolarization. Carbonic anhydrase (CA)VII contributes to this electrophysiological behavior by providing bicarbonate anion, which can mediate current through channels coupled to GABA_A receptors. Among the cytosolic CAs, the mechanism of action and inhibition of CA VII is less understood. We present herein the pharmacological evaluation of both enantiomers of an indanesulfonamide compound substituted by a pentafluorophenyl moiety against CA VII and five other human CA isoforms to evaluate their selectivity. The investigated compounds are powerful inhibitors of hCA VII, with K_i values in the range of 1.7-3.3 nm, but their selectivity needs to be improved. A molecular modeling study was conducted to rationalize the structure-activity relationships and provide useful insight into the future design of selective hCA VII inhibitors.