Carbonic Anhydrase I/II Dehydrates Bicarbonate Authored: May, B, 2011-08-07 Carbonic anhydrase I (CA1, Khalifah 1971, Pesando 1975, Simonsson et al. 1982, Ren & Lindskog 1992) and carbonic anhydrase II (CA2, Tibell et al. 1984, Jones & Shaw 1983, Ghannam et al. 1986) hydrate carbon dioxide (CO2) to yield bicarbonate (HCO3-) and a proton (H+). During the reaction a hydroxyl group bound by the zinc ion (Zn2+) attacks the CO2 molecule in the active site to directly form HCO3- (reviewed in Lindskog 1997). The HCO3- is displaced by water, which is then deprotonated by a histidine residue to recreate the Zn2+:hydroxyl group. Depending on the concentrations of reactants the reaction is reversible. EC Number: 4.2.1.1 Edited: May, B, 2011-08-07 Pubmed1554744 Pubmed234739 Pubmed3080418 Pubmed4994926 Pubmed6407977 Pubmed6433979 Pubmed6819139 Pubmed9336012 Reactome Database ID Release 431475436 Reactome, http://www.reactome.org ReactomeREACT_120912 Reviewed: Jassal, B, 2012-04-27