Nonaromatic Sulfonamide Group as an Ideal Anchor for Potent Human Carbonic Anhydrase Inhibitors: Role of Hydrogen-Bonding Networks in Ligand Binding and Drug Design

X-ray crystal structures of the adducts of human carbonic anhydrase (hCA) isozyme II with derivatives incorporating a sulfamide or sulfamic acid moiety are reported. The absence of a C-SO(2)NH(2) bond in the first type of compound can be exploited for the design of more potent and selective CA inhibitors. This study also explains why sulfate is a several-orders-of-magnitude weaker CA inhibitor compared to derivatives incorporating sulfonamide/sulfamide moieties.