View source for 1sf1

==NMR STRUCTURE OF HUMAN INSULIN under Amyloidogenic Condition, 15 STRUCTURES==
<StructureSection load='1sf1' size='340' side='right' caption='[[1sf1]], [[NMR_Ensembles_of_Models | 15 NMR models]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1sf1]] 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=1SF1 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1SF1 FirstGlance]. <br>
</td></tr><tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2hiu|2hiu]]</td></tr>
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">INS ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens])</td></tr>
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1sf1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1sf1 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1sf1 RCSB], [http://www.ebi.ac.uk/pdbsum/1sf1 PDBsum]</span></td></tr>
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== 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. 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/sf/1sf1_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Insulin undergoes aggregation-coupled misfolding to form a cross-beta assembly. Such fibrillation has long complicated its manufacture and use in the therapy of diabetes mellitus. Of interest as a model for disease-associated amyloids, insulin fibrillation is proposed to occur via partial unfolding of a monomeric intermediate. Here, we describe the solution structure of human insulin under amyloidogenic conditions (pH 2.4 and 60 degrees C). Use of an enhanced sensitivity cryogenic probe at high magnetic field avoids onset of fibrillation during spectral acquisition. A novel partial fold is observed in which the N-terminal segments of the A- and B-chains detach from the core. Unfolding of the N-terminal alpha-helix of the A-chain exposes a hydrophobic surface formed by native-like packing of the remaining alpha-helices. The C-terminal segment of the B-chain, although not well ordered, remains tethered to this partial helical core. We propose that detachment of N-terminal segments makes possible aberrant protein-protein interactions in an amyloidogenic nucleus. Non-cooperative unfolding of the N-terminal A-chain alpha-helix resembles that observed in models of proinsulin folding intermediates and foreshadows the extensive alpha --&gt; beta transition characteristic of mature fibrils.

Mechanism of insulin fibrillation: the structure of insulin under amyloidogenic conditions resembles a protein-folding intermediate.,Hua QX, Weiss MA J Biol Chem. 2004 May 14;279(20):21449-60. Epub 2004 Feb 26. PMID:14988398<ref>PMID:14988398</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Molecular Playground/Insulin|Molecular Playground/Insulin]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Hua, Q X.]]
[[Category: Weiss, M A.]]
[[Category: Hormone]]
[[Category: Hormone-growth factor complex]]
[[Category: Human insulin]]