Carbonic anhydrase (CA) (CA)

Carbonic anhydrases (CAs) are a ubiquitous family of zinc-dependent metalloenzymes that catalyze the rapid interconversion of carbon dioxide and water into bicarbonate and a proton [StatPearls: NBK541032]. This fundamental reaction is essential for maintaining acid-base balance, regulating intracellular and extracellular pH, and facilitating CO2 transport in the blood [UniProt: P00915]. In humans, sixteen different isoforms have been identified, each with specific tissue distributions and physiological roles, ranging from the cytosolic CA II to the membrane-bound, hypoxia-induced CA IX [PubMed: 28235330]. These enzymes are involved in diverse processes including aqueous humor production in the eye, bone resorption, and renal electrolyte handling [PubMed: 15149195]. Clinically, CA inhibitors like acetazolamide are used to treat glaucoma by reducing intraocular pressure and to manage altitude sickness by inducing metabolic acidosis [StatPearls: NBK541032]. Furthermore, CA IX and XII are recognized as significant biomarkers and therapeutic targets in oncology due to their role in tumor acidification and survival under hypoxic conditions [PubMed: 32630694]. The primary mechanism of drug interaction involves the reversible binding of sulfonamide-based inhibitors to the catalytic zinc ion, effectively shutting down enzymatic activity [StatPearls: NBK541032]. Therapeutic challenges include managing systemic side effects like metabolic acidosis and ensuring isoform selectivity to minimize off-target effects [PubMed: 15149195].

Other names

Carbonate dehydrataseCarbonic dehydrataseCA family

Reversible inhibition of the enzyme's catalytic activity by binding to the zinc ion in the active site, preventing the hydration of carbon dioxide to bicarbonate and protons [StatPearls: NBK541032].