[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.
The sulfamide analogue of the antiepileptic drug topiramate is a 210 times less potent inhibitor of isozyme II of the zinc enzyme carbonic anhydrase (CA, EC 126.96.36.199) compared to topiramate but effectively inhibits isozymes CA VA, VB, VII, XIII, and XIV (KI in the range of 21-35 nM). Its weak binding to CA II is due to a clash between one methyl group of the inhibitor and Ala65 and may be exploited for the drug design of compounds with lower affinity for this ubiquitous isozyme, as Ala65 is unique to CA II. As shown by X-ray crystallography, the sulfamide analogue binds to CA II with the deprotonated sulfamide moiety coordinated to Zn(II) and with the organic scaffold making an extended network of hydrogen bonds with Thr199, Gln92, His94, Asn62, and Thr200. Its binding to this isozyme is more similar to that of topiramate and quite different from that of the topiramate cyclic sulfate analogue RWJ-37947.
Carbonic anhydrase inhibitors: clash with Ala65 as a means for designing inhibitors with low affinity for the ubiquitous isozyme II, exemplified by the crystal structure of the topiramate sulfamide analogue.,Winum JY, Temperini C, El Cheikh K, Innocenti A, Vullo D, Ciattini S, Montero JL, Scozzafava A, Supuran CT J Med Chem. 2006 Nov 30;49(24):7024-31. PMID:17125255
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Venta PJ, Welty RJ, Johnson TM, Sly WS, Tashian RE. Carbonic anhydrase II deficiency syndrome in a Belgian family is caused by a point mutation at an invariant histidine residue (107 His----Tyr): complete structure of the normal human CA II gene. Am J Hum Genet. 1991 Nov;49(5):1082-90. PMID:1928091
↑ Roth DE, Venta PJ, Tashian RE, Sly WS. Molecular basis of human carbonic anhydrase II deficiency. Proc Natl Acad Sci U S A. 1992 Mar 1;89(5):1804-8. PMID:1542674
↑ Soda H, Yukizane S, Yoshida I, Koga Y, Aramaki S, Kato H. A point mutation in exon 3 (His 107-->Tyr) in two unrelated Japanese patients with carbonic anhydrase II deficiency with central nervous system involvement. Hum Genet. 1996 Apr;97(4):435-7. PMID:8834238
↑ Shah GN, Bonapace G, Hu PY, Strisciuglio P, Sly WS. Carbonic anhydrase II deficiency syndrome (osteopetrosis with renal tubular acidosis and brain calcification): novel mutations in CA2 identified by direct sequencing expand the opportunity for genotype-phenotype correlation. Hum Mutat. 2004 Sep;24(3):272. PMID:15300855 doi:10.1002/humu.9266
↑ Briganti F, Mangani S, Scozzafava A, Vernaglione G, Supuran CT. Carbonic anhydrase catalyzes cyanamide hydration to urea: is it mimicking the physiological reaction? J Biol Inorg Chem. 1999 Oct;4(5):528-36. PMID:10550681
↑ Kim CY, Whittington DA, Chang JS, Liao J, May JA, Christianson DW. Structural aspects of isozyme selectivity in the binding of inhibitors to carbonic anhydrases II and IV. J Med Chem. 2002 Feb 14;45(4):888-93. PMID:11831900
↑ Winum JY, Temperini C, El Cheikh K, Innocenti A, Vullo D, Ciattini S, Montero JL, Scozzafava A, Supuran CT. Carbonic anhydrase inhibitors: clash with Ala65 as a means for designing inhibitors with low affinity for the ubiquitous isozyme II, exemplified by the crystal structure of the topiramate sulfamide analogue. J Med Chem. 2006 Nov 30;49(24):7024-31. PMID:17125255 doi:10.1021/jm060807n