2k91
From Proteopedia
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| - | + | ==Enhancing the activity of insulin by stereospecific unfolding== | |
| - | === | + | <StructureSection load='2k91' size='340' side='right' caption='[[2k91]], [[NMR_Ensembles_of_Models | 20 NMR models]]' scene=''> |
| - | + | == Structural highlights == | |
| + | <table><tr><td colspan='2'>[[2k91]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2K91 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2K91 FirstGlance]. <br> | ||
| + | </td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2k91 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2k91 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2k91 RCSB], [http://www.ebi.ac.uk/pdbsum/2k91 PDBsum]</span></td></tr> | ||
| + | </table> | ||
| + | == Disease == | ||
| + | [[http://www.uniprot.org/uniprot/INS_HUMAN INS_HUMAN]] Defects in INS are the cause of familial hyperproinsulinemia (FHPRI) [MIM:[http://omim.org/entry/176730 176730]].<ref>PMID:3470784</ref> <ref>PMID:2196279</ref> <ref>PMID:4019786</ref> <ref>PMID:1601997</ref> Defects in INS are a cause of diabetes mellitus insulin-dependent type 2 (IDDM2) [MIM:[http://omim.org/entry/125852 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.<ref>PMID:18192540</ref> Defects in INS are a cause of diabetes mellitus permanent neonatal (PNDM) [MIM:[http://omim.org/entry/606176 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.<ref>PMID:17855560</ref> <ref>PMID:18162506</ref> Defects in INS are a cause of maturity-onset diabetes of the young type 10 (MODY10) [MIM:[http://omim.org/entry/613370 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.<ref>PMID:18192540</ref> <ref>PMID:18162506</ref> <ref>PMID:20226046</ref> | ||
| + | == Function == | ||
| + | [[http://www.uniprot.org/uniprot/INS_HUMAN 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. | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | A central tenet of molecular biology holds that the function of a protein is mediated by its structure. An inactive ground-state conformation may nonetheless be enjoined by the interplay of competing biological constraints. A model is provided by insulin, well characterized at atomic resolution by x-ray crystallography. Here, we demonstrate that the activity of the hormone is enhanced by stereospecific unfolding of a conserved structural element. A bifunctional beta-strand mediates both self-assembly (within beta-cell storage vesicles) and receptor binding (in the bloodstream). This strand is anchored by an invariant side chain (Phe(B24)); its substitution by Ala leads to an unstable but native-like analog of low activity. Substitution by d-Ala is equally destabilizing, and yet the protein diastereomer exhibits enhanced activity with segmental unfolding of the beta-strand. Corresponding photoactivable derivatives (containing l- or d-para-azido-Phe) cross-link to the insulin receptor with higher d-specific efficiency. Aberrant exposure of hydrophobic surfaces in the analogs is associated with accelerated fibrillation, a form of aggregation-coupled misfolding associated with cellular toxicity. Conservation of Phe(B24), enforced by its dual role in native self-assembly and induced fit, thus highlights the implicit role of misfolding as an evolutionary constraint. Whereas classical crystal structures of insulin depict its storage form, signaling requires engagement of a detachable arm at an extended receptor interface. Because this active conformation resembles an amyloidogenic intermediate, we envisage that induced fit and self-assembly represent complementary molecular adaptations to potential proteotoxicity. The cryptic threat of misfolding poses a universal constraint in the evolution of polypeptide sequences. | ||
| - | + | Enhancing the activity of a protein by stereospecific unfolding: conformational life cycle of insulin and its evolutionary origins.,Hua QX, Xu B, Huang K, Hu SQ, Nakagawa S, Jia W, Wang S, Whittaker J, Katsoyannis PG, Weiss MA J Biol Chem. 2009 May 22;284(21):14586-96. Epub 2009 Mar 25. PMID:19321436<ref>PMID:19321436</ref> | |
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| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
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==See Also== | ==See Also== | ||
*[[Molecular Playground/Insulin|Molecular Playground/Insulin]] | *[[Molecular Playground/Insulin|Molecular Playground/Insulin]] | ||
| - | + | == References == | |
| - | == | + | <references/> |
| - | + | __TOC__ | |
| + | </StructureSection> | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
| - | [[Category: Hu, S Q | + | [[Category: Hu, S Q]] |
| - | [[Category: Hua, Q X | + | [[Category: Hua, Q X]] |
| - | [[Category: Huang, K | + | [[Category: Huang, K]] |
| - | [[Category: Jia, W H | + | [[Category: Jia, W H]] |
| - | [[Category: Katsoyannis, P G | + | [[Category: Katsoyannis, P G]] |
| - | [[Category: Nakarawa, S | + | [[Category: Nakarawa, S]] |
| - | [[Category: Philips, N F.P | + | [[Category: Philips, N F.P]] |
| - | [[Category: Weiss, M A | + | [[Category: Weiss, M A]] |
| - | [[Category: Wittaker, J | + | [[Category: Wittaker, J]] |
| - | [[Category: Wittaker, L | + | [[Category: Wittaker, L]] |
| - | [[Category: Xu, B | + | [[Category: Xu, B]] |
[[Category: Carbohydrate metabolism]] | [[Category: Carbohydrate metabolism]] | ||
[[Category: Cleavage on pair of basic residue]] | [[Category: Cleavage on pair of basic residue]] | ||
Revision as of 12:55, 18 December 2014
Enhancing the activity of insulin by stereospecific unfolding
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Categories: Homo sapiens | Hu, S Q | Hua, Q X | Huang, K | Jia, W H | Katsoyannis, P G | Nakarawa, S | Philips, N F.P | Weiss, M A | Wittaker, J | Wittaker, L | Xu, B | Carbohydrate metabolism | Cleavage on pair of basic residue | Diabetes mellitus | Disease mutation | Glucose metabolism | Hormone | Insulin | Mutant | Secreted
