1qs3
From Proteopedia
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[[Image:1qs3.jpg|left|200px]] | [[Image:1qs3.jpg|left|200px]] | ||
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| - | + | {{STRUCTURE_1qs3| PDB=1qs3 | SCENE= }} | |
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'''NMR SOLUTION CONFORMATION OF AN ANTITOXIC ANALOG OF ALPHA-CONOTOXIN GI''' | '''NMR SOLUTION CONFORMATION OF AN ANTITOXIC ANALOG OF ALPHA-CONOTOXIN GI''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1QS3 is a [[Single protein]] structure | + | 1QS3 is a [[Single protein]] structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QS3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Han, K H.]] | [[Category: Han, K H.]] | ||
[[Category: Mok, K H.]] | [[Category: Mok, K H.]] | ||
| - | [[Category: | + | [[Category: Antitoxic analog]] |
| - | [[Category: | + | [[Category: Conotoxin]] |
| - | [[Category: | + | [[Category: Nicotinic acetylcholine receptor]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 06:38:30 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 03:38, 3 May 2008
NMR SOLUTION CONFORMATION OF AN ANTITOXIC ANALOG OF ALPHA-CONOTOXIN GI
Overview
The three-dimensional solution conformation of an 11-residue antitoxic analogue of alpha-conotoxin GI, des-Glu1-[Cys3Ala]-des-Cys13-conotoxin GI (CANPACGRHYS-NH(2), designated "GI-15" henceforth), has been determined using two-dimensional (1)H NMR spectroscopy. The disulfide loop region (1C-6C) and the C-terminal tail (8R-11S) are connected by a flexible hinge formed near 7G, and the pairwise backbone rmsds for the former and the latter are 0.58 and 0.65 A, respectively. Superpositioning GI-15 with the structure of alpha-conotoxin GI shows that the two share an essentially identical fold in the common first disulfide loop region (1C-6C). However, the absence of the second disulfide loop in GI-15 results in segmental motion of the C-terminal half, causing the key receptor subtype selectivity residue 8R (Arg9 in alpha-conotoxin GI) to lose its native spatial orientation. The combined features of structural equivalence in the disulfide loop and a mobile C-terminal tail appear to be responsible for the activity of GI-15 as a competitive antagonist against native toxin. Electrostatic surface potential comparisons of the first disulfide region of GI-15 with other alpha-conotoxins or receptor-bound states of acetylcholine and d-tubocurarine show a common protruding surface that may serve as the minimal binding determinant for the neuromuscular acetylcholine receptor alpha 1-subunit. On the basis of the original "Conus toxin macrosite model" [Olivera, B. M., Rivier, J., Scott, J. K., Hillyard, D. R., and Cruz, L. J. (1991) J. Biol. Chem. 266, 1923-1936], we propose a revised binding model which incorporates these results.
About this Structure
1QS3 is a Single protein structure. Full crystallographic information is available from OCA.
Reference
NMR solution conformation of an antitoxic analogue of alpha-conotoxin GI: identification of a common nicotinic acetylcholine receptor alpha 1-subunit binding surface for small ligands and alpha-conotoxins., Mok KH, Han KH, Biochemistry. 1999 Sep 14;38(37):11895-904. PMID:10508392 Page seeded by OCA on Sat May 3 06:38:30 2008
