CA2

CA2 is one of several (at least 7) isozymes of carbonic anhydrase. Carbonic anhydrase catalyzes the reversible hydration of carbon dioxide (1). It plays a role in osteoclast resorptive activity by acidification. The acid secretion process is initiated by CA2, which favors carbon dioxide hydration and converts it to bicarbonate. CA2 is also involved in proximal renal tubular bicarbonate reclamation and distal renal tubular acidification (2). Defects in CA2 are associated with osteopetrosis and renal tubular acidosis (1).