1cph

CONFORMATIONAL CHANGES IN CUBIC INSULIN CRYSTALS IN THE PH RANGE 7-11

spinqualitylabelsall models 1cph, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1cph is a 2 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: DCE, NA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function INS_BOVIN 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 PubMed To determine the effect of variations in the charge distribution on the conformation of a protein molecule, we have solved the structures of bovine cubic insulin over a pH range from 7 to 11 in 0.1 M and 1 M sodium salt solutions. The x-ray data were collected beyond 2-A resolution and the R factors for the refined models ranged from 0.16 to 0.20. Whereas the positions of most protein and well-ordered solvent atoms are conserved, about 30% of residues alter their predominant conformation as the pH is changed. Conformational switching of A5 Gln and B10 His correlates with the pH dependence of monovalent cation binding to insulin in cubic crystals. Shifts in the relative positions of the A chain NH2-terminal and B chain COOH-terminal groups are probably due to titration of the A1 alpha-amino group. Two alternative positions of B25 Phe and A21 Asn observed in cubic insulin at pH 11 are similar to those found in two independent molecules of the 2Zn insulin dimer at pH 6.4. The conformational changes of the insulin amino acids appear to be only loosely coupled at distant protein sites. Shifts in the equilibrium between distinct conformational substates as the charge distribution on the protein is altered are analogous to the electrostatically triggered movements that occur in many functional protein reactions. Conformational changes in cubic insulin crystals in the pH range 7-11.,Gursky O, Badger J, Li Y, Caspar DL Biophys J. 1992 Nov;63(5):1210-20. PMID:1477273 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Insulin 3D Structures

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