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| | {{STRUCTURE_1lqi| PDB=1lqi | SCENE= }} | | {{STRUCTURE_1lqi| PDB=1lqi | SCENE= }} |
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| - | '''INSECTICIDAL ALPHA SCORPION TOXIN ISOLATED FROM THE VENOM OF SCORPION LEIURUS QUINQUESTRIATUS HEBRAEUS, NMR, 29 STRUCTURES'''
| + | ===INSECTICIDAL ALPHA SCORPION TOXIN ISOLATED FROM THE VENOM OF SCORPION LEIURUS QUINQUESTRIATUS HEBRAEUS, NMR, 29 STRUCTURES=== |
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| - | ==Overview==
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| - | The solution structure of a recombinant active alpha-neurotoxin from Leiurus quinquestriatus hebraeus, Lqh(alpha)IT, was determined by proton two-dimensional nuclear magnetic resonance spectroscopy (2D NMR). This toxin is the most insecticidal among scorpion alpha-neurotoxins and, therefore, serves as a model for clarifying the structural basis for their biological activity and selective toxicity. A set of 29 structures was generated without constraint violations exceeding 0.4 A. These structures had root mean square deviations of 0.49 and 1.00 A with respect to the average structure for backbone atoms and all heavy atoms, respectively. Similarly to other scorpion toxins, the structure of Lqh(alpha)IT consists of an alpha-helix, a three-strand antiparallel beta-sheet, three type I tight turns, a five-residue turn, and a hydrophobic patch that includes tyrosine and tryptophan rings in a "herringbone" arrangement. Positive phi angles were found for Ala50 and Asn11, suggesting their proximity to functionally important regions of the molecule. The sample exhibited conformational heterogeneity over a wide range of experimental conditions, and two conformations were observed for the majority of protein residues. The ratio between these conformations was temperature-dependent, and the rate of their interconversions was estimated to be on the order of 1-5 s(-1) at 308 K. The conformation of the polypeptide backbone of Lqh(alpha)IT is very similar to that of the most active antimammalian scorpion alpha-toxin, AaHII, from Androctonus australis Hector (60% amino acid sequence homology). Yet, several important differences were observed at the 5-residue turn comprising residues Lys8-Cys12, the C-terminal segment, and the mutual disposition of these two regions. 2D NMR studies of the R64H mutant, which is 3 times more toxic than the unmodified Lqh(alpha)IT, demonstrated the importance of the spatial orientation of the last residue side chain for toxicity of Lqh(alpha)IT. | + | The line below this paragraph, {{ABSTRACT_PUBMED_9054546}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 9054546 is the PubMed ID number. |
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| | + | {{ABSTRACT_PUBMED_9054546}} |
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| | ==About this Structure== | | ==About this Structure== |
| - | 1LQI is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Leiurus_quinquestriatus_hebraeus Leiurus quinquestriatus hebraeus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LQI OCA]. | + | 1LQI is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Leiurus_quinquestriatus_hebraeus Leiurus quinquestriatus hebraeus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LQI OCA]. |
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| | ==Reference== | | ==Reference== |
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| | [[Category: Signal]] | | [[Category: Signal]] |
| | [[Category: Sodium channel inhibitor]] | | [[Category: Sodium channel inhibitor]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 00:10:55 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jul 2 21:47:59 2008'' |
Revision as of 18:48, 2 July 2008
Template:STRUCTURE 1lqi
INSECTICIDAL ALPHA SCORPION TOXIN ISOLATED FROM THE VENOM OF SCORPION LEIURUS QUINQUESTRIATUS HEBRAEUS, NMR, 29 STRUCTURES
Template:ABSTRACT PUBMED 9054546
About this Structure
1LQI is a Single protein structure of sequence from Leiurus quinquestriatus hebraeus. Full experimental information is available from OCA.
Reference
Solution structures of a highly insecticidal recombinant scorpion alpha-toxin and a mutant with increased activity., Tugarinov V, Kustanovich I, Zilberberg N, Gurevitz M, Anglister J, Biochemistry. 1997 Mar 4;36(9):2414-24. PMID:9054546
Page seeded by OCA on Wed Jul 2 21:47:59 2008
