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- | [[Image:1q4v.gif|left|200px]] | + | {{Seed}} |
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| {{STRUCTURE_1q4v| PDB=1q4v | SCENE= }} | | {{STRUCTURE_1q4v| PDB=1q4v | SCENE= }} |
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- | '''CRYSTAL STRUCTURE OF ALLO-ILEA2-INSULIN, AN INACTIVE CHIRAL ANALOGUE: IMPLICATIONS FOR THE MECHANISM OF RECEPTOR'''
| + | ===CRYSTAL STRUCTURE OF ALLO-ILEA2-INSULIN, AN INACTIVE CHIRAL ANALOGUE: IMPLICATIONS FOR THE MECHANISM OF RECEPTOR=== |
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- | ==Overview==
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- | The crystal structure of an inactive chiral analogue of insulin containing nonstandard substitution allo-Ile(A2) is described at 2.0 A resolution. In native insulin, the invariant Ile(A2) side chain anchors the N-terminal alpha-helix of the A-chain to the hydrophobic core. The structure of the variant protein was determined by molecular replacement as a T(3)R(3) zinc hexamer. Whereas respective T- and R-state main-chain structures are similar to those of native insulin (main-chain root-mean-square deviations (RMSD) of 0.45 and 0.54 A, respectively), differences in core packing are observed near the variant side chain. The R-state core resembles that of the native R-state with a local inversion of A2 orientation (core side chain RMSD 0.75 A excluding A2); in the T-state, allo-Ile(A2) exhibits an altered conformation in association with the reorganization of the surrounding side chains (RMSD 0.98 A). Surprisingly, the core of the R-state is similar to that observed in solution nuclear magnetic resonance (NMR) studies of an engineered T-like monomer containing the same chiral substitution (allo-Ile(A2)-DKP-insulin; Xu, B., Hua, Q. X., Nakagawa, S. H., Jia, W., Chu, Y. C., Katsoyannis, P. G., and Weiss, M. A. (2002) J. Mol. Biol. 316, 435-441). Simulation of NOESY spectra based on crystallographic protomers enables the analysis of similarities and differences in solution. The different responses of the T- and R-state cores to chiral perturbation illustrates both their intrinsic plasticity and constraints imposed by hexamer assembly. Although variant T- and R-protomers retain nativelike protein surfaces, the receptor-binding activity of allo-Ile(A2)-insulin is low (2% relative to native insulin). This seeming paradox suggests that insulin undergoes a change in conformation to expose Ile(A2) at the hormone-receptor interface.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_14596591}}, adds the Publication Abstract to the page |
| + | (as it appears on PubMed at http://www.pubmed.gov), where 14596591 is the PubMed ID number. |
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| + | {{ABSTRACT_PUBMED_14596591}} |
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| ==About this Structure== | | ==About this Structure== |
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| [[Category: Insulin receptor]] | | [[Category: Insulin receptor]] |
| [[Category: Protein unfolding]] | | [[Category: Protein unfolding]] |
- | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 05:52:06 2008'' | + | |
| + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 14:25:21 2008'' |
Revision as of 11:25, 29 July 2008
Template:STRUCTURE 1q4v
CRYSTAL STRUCTURE OF ALLO-ILEA2-INSULIN, AN INACTIVE CHIRAL ANALOGUE: IMPLICATIONS FOR THE MECHANISM OF RECEPTOR
Template:ABSTRACT PUBMED 14596591
About this Structure
1Q4V is a Single protein structure. This structure supersedes the now removed PDB entries and 1lw8. Full crystallographic information is available from OCA.
Reference
Crystal structure of allo-Ile(A2)-insulin, an inactive chiral analogue: implications for the mechanism of receptor binding., Wan ZL, Xu B, Chu YC, Katsoyannis PG, Weiss MA, Biochemistry. 2003 Nov 11;42(44):12770-83. PMID:14596591
Page seeded by OCA on Tue Jul 29 14:25:21 2008