4iwz | pdb_00004iwz
structure of hCAII in complex with an acetazolamide derivative
Structural highlights
Disease[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.[1] [2] [3] [4] [5] Function[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.[6] [7] Publication Abstract from PubMedThe high resolution crystal structure of 5-(2-thienylacetamido)-1,3,4-thiadiazole-2-sulfonamide complexed to human (h) carbonic anhydrase (CA, EC 4.2.1.1) isoform hCA II is reported. The compound binds in a similar manner with acetazolamide when the sulfamoyl-thiadiazolyl-acetamido fragment of the two compounds is considered, but the thienyl tail was positioned in the subpocket 2, rarely observed by other investigated CA inhibitors. This positioning allows interaction with amino acid residues (such as Asn67, Ile91, Gln92 and Val121 which are variable in other isoforms of medicinal chemistry interest, such as hCA I, IX and XII. Indeed, the investigated sulfonamide was a medium potency hCA I and II inhibitor but was highly effective as a hCA IX and XII inhibitor. This different behavior with respect to acetazolamide (a promiscuous inhibitor of all these isoforms) has been explained by resolving the crystal structure, and may be used to design more isoform-selective compounds. Effect of incorporating a thiophene tail in the scaffold of acetazolamide on the inhibition of human carbonic anhydrase isoforms I, II, IX and XII.,Biswas S, McKenna R, Supuran CT Bioorg Med Chem Lett. 2013 Oct 15;23(20):5646-9. doi: 10.1016/j.bmcl.2013.08.019., Epub 2013 Aug 13. PMID:23993330[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||||||
