View source for 1ioh


==INSULIN MUTANT A8 HIS,(B1, B10, B16, B27)GLU, DES-B30, NMR, 26 STRUCTURES==
<StructureSection load='1ioh' size='340' side='right'caption='[[1ioh]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ioh]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IOH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1IOH FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 26 models</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1ioh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ioh OCA], [https://pdbe.org/1ioh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ioh RCSB], [https://www.ebi.ac.uk/pdbsum/1ioh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ioh ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/INS_HUMAN INS_HUMAN] Defects in INS are the cause of familial hyperproinsulinemia (FHPRI) [MIM:[https://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:[https://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:[https://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:[https://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 ==
[https://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.
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== Publication Abstract from PubMed ==
Studies of naturally occuring and chemically modified insulins have established that the NH2-terminal helix of the A-chain is important in conferring affinity in insulin-receptor interactions. Nevertheless, the three-dimensional structural basis for these observations has not previously been studied in detail. To correlate structure and function in this region of the molecule, we have used the solution structure of an engineered monomer (GluB1, GluB10, GluB16, GluB27, desB30)-insulin (4E insulin) as a template for design of A-chain mutants associated with enhanced or greatly diminished affinity for the insulin receptor. In the context of 4E insulin, the employed mutants, i.e. ThrA8--&gt;His and ValA3--&gt;Gly, result in species with 143% and 0.1% biological activity, respectively, relative to human insulin. The high-resolution NMR studies reveal two well-defined structures each resembling the template. However, significant structural differences are evident notably in residues A2-A8 and their immediate environment. In comparison with the template structure, the A8His mutation enhances the helical character of residues A2-A8. This structural change leads to additional exposure of a hydrophobic patch mainly consisting of species invariant residues. In contrast, the A3Gly mutation leads to stretching and disruption of the A2-A8 helix and changes both the dimensions and the access to the hydrophobic patch exposed in the more active insulins. We conclude that the mutations induce small, yet decisive structural changes that either mediate or inhibit the subtle conformational adjustments involved in the presentation of this part of the insulin pharmacophore to the receptor.

The relationship between insulin bioactivity and structure in the NH2-terminal A-chain helix.,Olsen HB, Ludvigsen S, Kaarsholm NC J Mol Biol. 1998 Nov 27;284(2):477-88. PMID:9813131<ref>PMID:9813131</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1ioh" style="background-color:#fffaf0;"></div>

==See Also==
*[[Insulin 3D Structures|Insulin 3D Structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Kaarsholm NC]]
[[Category: Ludvigsen S]]
[[Category: Olsen HB]]