From Proteopediaproteopedia link
Crystal structure of the human carbonic anhydrase II in complex with N-hydroxy benzenesulfonamide
[CAH2_HUMAN] Defects in CA2 are the cause of osteopetrosis autosomal recessive type 3 (OPTB3) [MIM:259730]; also known as osteopetrosis with renal tubular acidosis, carbonic anhydrase II deficiency syndrome, Guibaud-Vainsel syndrome or marble brain disease. Osteopetrosis is a rare genetic disease characterized by abnormally dense bone, due to defective resorption of immature bone. The disorder occurs in two forms: a severe autosomal recessive form occurring in utero, infancy, or childhood, and a benign autosomal dominant form occurring in adolescence or adulthood. Autosomal recessive osteopetrosis is usually associated with normal or elevated amount of non-functional osteoclasts. OPTB3 is associated with renal tubular acidosis, cerebral calcification (marble brain disease) and in some cases with mental retardation.    
[CAH2_HUMAN] Essential for bone resorption and osteoclast differentiation (By similarity). Reversible hydration of carbon dioxide. Can hydrate cyanamide to urea. Involved in the regulation of fluid secretion into the anterior chamber of the eye. 
Publication Abstract from PubMed
N-substituted benzenesulfonamides, incorporating the N-amino-, N-hydroxy- and N-methoxy-moieties at the sulfonamide zinc binding group, have been investigated as CAIs by means of inhibition and structural studies, unraveling interesting aspects related to their inhibition mechanism.
Carbonic anhydrase inhibitors: X-ray crystallographic studies for the binding of N-substituted benzenesulfonamides to human isoform II.,Di Fiore A, Maresca A, Alterio V, Supuran CT, De Simone G Chem Commun (Camb). 2011 Nov 14;47(42):11636-8. Epub 2011 Sep 26. PMID:21952494
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.