[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 fructose-based sugar sulphamate RWJ-37497, a potent analogue of the widely used anti-epileptic drug topiramate, possesses anti-convulsant and carbonic anhydrase-inhibitory activities. We have studied the binding interactions of RWJ-37497 in the active site of human carbonic anhydrase II by X-ray crystallography. The atomic positions of the enzyme inhibitor complex were refined at a resolution of 2.1 A (1 A=0.1 nm) to the final crystallographic R and R(free) values of 0.18 and 0.23, respectively. The inhibitor co-ordinates to the active-site zinc ion through its oxygen atom and the ionized nitrogen atom of the sulphamate group by replacing the metal-bound water molecules, although the sulphamoyl oxygen atom provides a rather lengthy co-ordination. The 4,5-cyclic sulphate group is positioned in a hydrophobic pocket of the active site, making contacts with the residues Phe-131, Leu-198, Pro-201 and Pro-202. Since the ligand was found to be intact, concerns about RWJ-37947 irreversibly alkylating the enzyme through its 4,5-cyclic sulphate group were dispelled.
Crystal structure of human carbonic anhydrase II complexed with an anti-convulsant sugar sulphamate.,Recacha R, Costanzo MJ, Maryanoff BE, Chattopadhyay D Biochem J. 2002 Feb 1;361(Pt 3):437-41. PMID:11802772
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
↑ Recacha R, Costanzo MJ, Maryanoff BE, Chattopadhyay D. Crystal structure of human carbonic anhydrase II complexed with an anti-convulsant sugar sulphamate. Biochem J. 2002 Feb 1;361(Pt 3):437-41. PMID:11802772