1lxg: Difference between revisions
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==Solution structure of alpha-cobratoxin complexed with a cognate peptide (structure ensemble)== | ==Solution structure of alpha-cobratoxin complexed with a cognate peptide (structure ensemble)== | ||
<StructureSection load='1lxg' size='340' side='right' caption='[[1lxg]], [[NMR_Ensembles_of_Models | 10 NMR models]]' scene=''> | <StructureSection load='1lxg' size='340' side='right'caption='[[1lxg]], [[NMR_Ensembles_of_Models | 10 NMR models]]' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1lxg]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Naja_kaouthia Naja kaouthia] and [http://en.wikipedia.org/wiki/Pacific_electric_ray Pacific electric ray]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LXG OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1LXG FirstGlance]. <br> | <table><tr><td colspan='2'>[[1lxg]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Naja_kaouthia Naja kaouthia] and [http://en.wikipedia.org/wiki/Pacific_electric_ray Pacific electric ray]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LXG OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1LXG FirstGlance]. <br> | ||
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__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: Large Structures]] | |||
[[Category: Naja kaouthia]] | [[Category: Naja kaouthia]] | ||
[[Category: Pacific electric ray]] | [[Category: Pacific electric ray]] |
Revision as of 15:09, 13 November 2019
Solution structure of alpha-cobratoxin complexed with a cognate peptide (structure ensemble)Solution structure of alpha-cobratoxin complexed with a cognate peptide (structure ensemble)
Structural highlights
Function[NXL1_NAJKA] The monomeric form binds with high affinity to muscular, Torpedo (muscle-type), and neuronal alpha-7 nicotinic acetylcholine receptors (nAChR). Has no effect on alpha-3/beta-2 nAChR. Causes paralysis by preventing acetylcholine binding to the nAChR. Does not show any blockade of the nicotine-evoked release of dopamine and does not affect ACh release. In mice lung cancer, causes reduction of tumor growth.[1] [2] [3] [4] [5] [6] [7] [8] [9] The homodimeric form binds with low affinity to Torpedo (muscle-type) and alpha-7 nAChRs, whereas it acquires the capacity to block alpha-3/beta-2 nAChRs.[10] [11] [12] [13] [14] [15] [16] [17] [18] [ACHA_TORCA] After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe alpha18-mer peptide, spanning residues 181-198 of the Torpedo nicotinic acetylcholine receptor alpha1 subunit, contains key binding determinants for agonists and competitive antagonists. To investigate whether the alpha18-mer can bind other alpha-neurotoxins besides alpha-bungarotoxin, we designed a two-dimensional (1)H-(15)N heteronuclear single quantum correlation experiment to screen four related neurotoxins for their binding ability to the peptide. Of the four toxins tested (erabutoxin a, erabutoxin b, LSIII, and alpha-cobratoxin), only alpha-cobratoxin binds the alpha18-mer to form a 1:1 complex. The NMR solution structure of the alpha-cobratoxin.alpha18-mer complex was determined with a backbone root mean square deviation of 1.46 A. In the structure, alpha-cobratoxin contacts the alpha18-mer at the tips of loop I and II and through C-terminal cationic residues. The contact zone derived from the intermolecular nuclear Overhauser effects is in agreement with recent biochemical data. Furthermore, the structural models support the involvement of cation-pi interactions in stabilizing the complex. In addition, the binding screen results suggest that C-terminal cationic residues of alpha-bungarotoxin and alpha-cobratoxin contribute significantly to binding of the alpha18-mer. Finally, we present a structural model for nicotinic acetylcholine receptor-alpha-cobratoxin interaction by superimposing the alpha-cobratoxin.alpha18-mer complex onto the crystal structure of the acetylcholine-binding protein (Protein Data Bank code ). NMR-based binding screen and structural analysis of the complex formed between alpha-cobratoxin and an 18-mer cognate peptide derived from the alpha 1 subunit of the nicotinic acetylcholine receptor from Torpedo californica.,Zeng H, Hawrot E J Biol Chem. 2002 Oct 4;277(40):37439-45. Epub 2002 Jul 19. PMID:12133834[19] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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