Figure 1
Carboxylic acid inhibitor-binding modes of CA. (a), (b), (c) Observed crystallographic data from PDB entries 3ks3, 8dj9 and 5eh8, respectively; (d), (e), (f) schematic models. (a, d) hCA II active site with ZBS, (b, e) direct inhibition in which the carboxylic acid displaces the ZBS and (c, f) indirect inhibition with the carboxylic acid hydrogen-bonded to the ZBS. (a), (b), (c) Zinc is depicted as a magenta sphere, water as a red sphere, the O atoms of the carboxylic acid moiety of the inhibitor are in red and the active-site histidine residues are labeled. (d), (e), (f) Zinc direct metal coordination is depicted as dashed lines, with hydrogen bonds as solid lines; the respective distances are labeled. |