Carbonic anhydrases (CAs) are a large family of zinc metalloenzymes that catalyze the reversible hydration of carbon dioxide. They participate in a variety of biological processes, including respiration, calcification, acid-base balance, bone resorption, and the formation of aqueous humor, cerebrospinal fluid, saliva, and gastric acid. They show extensive diversity in tissue distribution and in their subcellular localization. CA XI is likely a secreted protein, however, radical changes at active site residues completely conserved in CA isozymes with catalytic activity, make it unlikely that it has carbonic anhydrase activity. It shares properties in common with two other acatalytic CA isoforms, CA VIII and CA X. CA XI is most abundantly expressed in brain, and may play a general role in the central nervous system.
^Lovejoy DA, Hewett-Emmett D, Porter CA, Cepoi D, Sheffield A, Vale WW, Tashian RE (Feb 1999). "Evolutionarily conserved, "acatalytic" carbonic anhydrase-related protein XI contains a sequence motif present in the neuropeptide sauvagine: the human CA-RP XI gene (CA11) is embedded between the secretor gene cluster and the DBP gene at 19q13.3". Genomics54 (3): 484–93. doi:10.1006/geno.1998.5585. PMID9878252.Check date values in: |year= / |date= mismatch (help)
Bellingham J, Gregory-Evans K, Gregory-Evans CY (1998). "Sequence and tissue expression of a novel human carbonic anhydrase-related protein, CARP-2, mapping to chromosome 19q13.3". Biochem. Biophys. Res. Commun.253 (2): 364–7. doi:10.1006/bbrc.1998.9449. PMID9878543.
Fujikawa-Adachi K, Nishimori I, Taguchi T, Yuri K, Onishi S (1999). "cDNA sequence, mRNA expression, and chromosomal localization of human carbonic anhydrase-related protein, CA-RP XI". Biochim. Biophys. Acta1431 (2): 518–24. doi:10.1016/S0167-4838(99)00067-9. PMID10350627.
Okamoto N, Fujikawa-Adachi K, Nishimori I, Taniuchi K, Onishi S (2001). "cDNA sequence of human carbonic anhydrase-related protein, CA-RP X: mRNA expressions of CA-RP X and XI in human brain". Biochim. Biophys. Acta1518 (3): 311–6. doi:10.1016/s0167-4781(01)00193-2. PMID11311946.
Taniuchi K, Nishimori I, Takeuchi T, Fujikawa-Adachi K, Ohtsuki Y, Onishi S (2002). "Developmental expression of carbonic anhydrase-related proteins VIII, X, and XI in the human brain". Neuroscience112 (1): 93–9. doi:10.1016/S0306-4522(02)00066-0. PMID12044474.