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1aiy

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1aiy, 10 NMR models ()
Ligands: ,
Resources: FirstGlance, OCA, RCSB, PDBsum
Coordinates: save as pdb, mmCIF, xml


Contents

R6 HUMAN INSULIN HEXAMER (SYMMETRIC), NMR, 10 STRUCTURES

Publication Abstract from PubMed

The three-dimensional solution structure of the phenol-stabilized 36 kDa R6 insulin hexamer was determined by NMR spectroscopy and restrained molecular dynamics. The hexamer structures were derived using a stepwise procedure. Initially, 60 monomers were obtained by distance geometry from 665 NOE-derived distance restraints and three disulfide bridges. Subsequently, the hexamer structures were calculated by simulated annealing, using 30 hexamers constructed from the best 36 monomer structures as the starting models. The NMR data show that the aromatic ring of residue Phe(B25) can take two different orientations in the solution hexamer: one in which it points inward (molecule 1, about 90%) and one in which it points outward from the surface of the monomer (molecule 2, about 10%). Therefore, two hexamer structures were calculated: a symmetric hexamer consisting of six molecule 1 monomers and a nonsymmetric hexamer consisting of five molecule 1 monomers and one molecule 2 monomer. For each of the six monomers, the restraints used in the calculations of the hexamer structures include, in addition to the intramonomeric restraints, 25 NOEs between insulin and phenol, 23 NOEs and two hydrogen bonds across the dimer interface, nine NOEs across the trimer interface, and five intramonomeric or two intermonomeric NOEs, respectively, specifying the different orientations of the Phe(B25) ring. The coordination of the two Zn atoms was defined by eight distance restraints. Thus, a total of 4394 and 4391 distance restraints, respectively, were used in the two hexamer calculations. The NOE restraints were classified in an iterative process as intra- or intermonomeric on the basis of their consistency or inconsistency with the structure of the monomer. The assignment of the dimer- and trimer-specific NOEs was made using the crystal structure of the R6 hexamer as the starting model. For both solution hexamers, the average backbone rms deviation is 0.81 A, if the less well-defined N- and C-terminal residues are excluded. The corresponding rms deviations for all heavy atoms are 1.17 and 1.19 A for the nonsymmetric and symmetric hexamer, respectively. The overall solution structure of the R6 insulin hexamer is compact, rigid, and symmetric and resembles the corresponding crystal structure. However, the extension of the B-chain alpha-helix, which characterizes the R state, is shorter in the solution structure than in the crystal structure. Also, the study shows that the orientation of the Phe(B25) ring has no effect on the structure of the rest of the molecule, within the uncertainty of the structure determination. The importance of these findings for the current model for the insulin-receptor interaction is discussed.

Solution structures of the R6 human insulin hexamer,., Chang X, Jorgensen AM, Bardrum P, Led JJ, Biochemistry. 1997 Aug 5;36(31):9409-22. PMID:9235985

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Disease

[INS_HUMAN] Defects in INS are the cause of familial hyperproinsulinemia (FHPRI) [MIM:176730].[1][2][3][4] Defects in INS are a cause of diabetes mellitus insulin-dependent type 2 (IDDM2) [MIM:125852]. IDDM2 is a multifactorial disorder of glucose homeostasis that is characterized by susceptibility to ketoacidosis in the absence of insulin therapy. Clinical fetaures are polydipsia, polyphagia and polyuria which result from hyperglycemia-induced osmotic diuresis and secondary thirst. These derangements result in long-term complications that affect the eyes, kidneys, nerves, and blood vessels.[5] Defects in INS are a cause of diabetes mellitus permanent neonatal (PNDM) [MIM:606176]. PNDM is a rare form of diabetes distinct from childhood-onset autoimmune diabetes mellitus type 1. It is characterized by insulin-requiring hyperglycemia that is diagnosed within the first months of life. Permanent neonatal diabetes requires lifelong therapy.[6][7] Defects in INS are a cause of maturity-onset diabetes of the young type 10 (MODY10) [MIM:613370]. MODY10 is a form of diabetes that is characterized by an autosomal dominant mode of inheritance, onset in childhood or early adulthood (usually before 25 years of age), a primary defect in insulin secretion and frequent insulin-independence at the beginning of the disease.[8][9][10]

Function

[INS_HUMAN] 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.

About this Structure

1aiy is a 12 chain structure with sequence from Homo sapiens. Full experimental information is available from OCA.

See Also

Reference

  • Chang X, Jorgensen AM, Bardrum P, Led JJ. Solution structures of the R6 human insulin hexamer,. Biochemistry. 1997 Aug 5;36(31):9409-22. PMID:9235985 doi:10.1021/bi9631069
  1. Chan SJ, Seino S, Gruppuso PA, Schwartz R, Steiner DF. A mutation in the B chain coding region is associated with impaired proinsulin conversion in a family with hyperproinsulinemia. Proc Natl Acad Sci U S A. 1987 Apr;84(8):2194-7. PMID:3470784
  2. Barbetti F, Raben N, Kadowaki T, Cama A, Accili D, Gabbay KH, Merenich JA, Taylor SI, Roth J. Two unrelated patients with familial hyperproinsulinemia due to a mutation substituting histidine for arginine at position 65 in the proinsulin molecule: identification of the mutation by direct sequencing of genomic deoxyribonucleic acid amplified by polymerase chain reaction. J Clin Endocrinol Metab. 1990 Jul;71(1):164-9. PMID:2196279
  3. Shibasaki Y, Kawakami T, Kanazawa Y, Akanuma Y, Takaku F. Posttranslational cleavage of proinsulin is blocked by a point mutation in familial hyperproinsulinemia. J Clin Invest. 1985 Jul;76(1):378-80. PMID:4019786 doi:http://dx.doi.org/10.1172/JCI111973
  4. Yano H, Kitano N, Morimoto M, Polonsky KS, Imura H, Seino Y. A novel point mutation in the human insulin gene giving rise to hyperproinsulinemia (proinsulin Kyoto). J Clin Invest. 1992 Jun;89(6):1902-7. PMID:1601997 doi:http://dx.doi.org/10.1172/JCI115795
  5. Molven A, Ringdal M, Nordbo AM, Raeder H, Stoy J, Lipkind GM, Steiner DF, Philipson LH, Bergmann I, Aarskog D, Undlien DE, Joner G, Sovik O, Bell GI, Njolstad PR. Mutations in the insulin gene can cause MODY and autoantibody-negative type 1 diabetes. Diabetes. 2008 Apr;57(4):1131-5. doi: 10.2337/db07-1467. Epub 2008 Jan 11. PMID:18192540 doi:10.2337/db07-1467
  6. Stoy J, Edghill EL, Flanagan SE, Ye H, Paz VP, Pluzhnikov A, Below JE, Hayes MG, Cox NJ, Lipkind GM, Lipton RB, Greeley SA, Patch AM, Ellard S, Steiner DF, Hattersley AT, Philipson LH, Bell GI. Insulin gene mutations as a cause of permanent neonatal diabetes. Proc Natl Acad Sci U S A. 2007 Sep 18;104(38):15040-4. Epub 2007 Sep 12. PMID:17855560 doi:10.1073/pnas.0707291104
  7. Edghill EL, Flanagan SE, Patch AM, Boustred C, Parrish A, Shields B, Shepherd MH, Hussain K, Kapoor RR, Malecki M, MacDonald MJ, Stoy J, Steiner DF, Philipson LH, Bell GI, Hattersley AT, Ellard S. Insulin mutation screening in 1,044 patients with diabetes: mutations in the INS gene are a common cause of neonatal diabetes but a rare cause of diabetes diagnosed in childhood or adulthood. Diabetes. 2008 Apr;57(4):1034-42. Epub 2007 Dec 27. PMID:18162506 doi:10.2337/db07-1405
  8. Molven A, Ringdal M, Nordbo AM, Raeder H, Stoy J, Lipkind GM, Steiner DF, Philipson LH, Bergmann I, Aarskog D, Undlien DE, Joner G, Sovik O, Bell GI, Njolstad PR. Mutations in the insulin gene can cause MODY and autoantibody-negative type 1 diabetes. Diabetes. 2008 Apr;57(4):1131-5. doi: 10.2337/db07-1467. Epub 2008 Jan 11. PMID:18192540 doi:10.2337/db07-1467
  9. Edghill EL, Flanagan SE, Patch AM, Boustred C, Parrish A, Shields B, Shepherd MH, Hussain K, Kapoor RR, Malecki M, MacDonald MJ, Stoy J, Steiner DF, Philipson LH, Bell GI, Hattersley AT, Ellard S. Insulin mutation screening in 1,044 patients with diabetes: mutations in the INS gene are a common cause of neonatal diabetes but a rare cause of diabetes diagnosed in childhood or adulthood. Diabetes. 2008 Apr;57(4):1034-42. Epub 2007 Dec 27. PMID:18162506 doi:10.2337/db07-1405
  10. Boesgaard TW, Pruhova S, Andersson EA, Cinek O, Obermannova B, Lauenborg J, Damm P, Bergholdt R, Pociot F, Pisinger C, Barbetti F, Lebl J, Pedersen O, Hansen T. Further evidence that mutations in INS can be a rare cause of Maturity-Onset Diabetes of the Young (MODY). BMC Med Genet. 2010 Mar 12;11:42. doi: 10.1186/1471-2350-11-42. PMID:20226046 doi:10.1186/1471-2350-11-42

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