2zpp
Neutron crystal structure of cubic insulin at pD9Neutron crystal structure of cubic insulin at pD9
Structural highlights
FunctionINS_PIG Insulin decreases blood glucose concentration. It increases cell permeability to monosaccharides, amino acids and fatty acids. It accelerates glycolysis, the pentose phosphate cycle, and glycogen synthesis in liver. Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedInsulin is stored in pancreatic beta-cell as hexameric form with Zn2+ ions, while the hormonally active form is monomer. The hexamer requires the coordination of Zn2+ ions to the HisB10. In order to reveal the mechanism of the hexamerization of insulin, we investigated the Zn2+ free insulin at pD6.6 and pD9 by neutron crystallographic analyses. HisB10 is doubly protonated not only at pD6.6 but also at pD9, indicating an abnormal pK(a) of this histidine. It is suggested that HisB10 acts on a strong cation capture and contributes to the high stability of the hexameric form in pancreas. An abnormal pK(a) value of internal histidine of the insulin molecule revealed by neutron crystallographic analysis.,Ishikawa T, Chatake T, Morimoto Y, Maeda M, Kurihara K, Tanaka I, Niimura N Biochem Biophys Res Commun. 2008 Nov 7;376(1):32-5. Epub 2008 Aug 24. PMID:18725203[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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