1g2g
From Proteopedia
(New page: 200px<br /><applet load="1g2g" size="450" color="white" frame="true" align="right" spinBox="true" caption="1g2g" /> '''MINIMAL CONFORMATION OF THE ALPHA-CONOTOXIN ...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1g2g.gif|left|200px]]<br /><applet load="1g2g" size=" | + | [[Image:1g2g.gif|left|200px]]<br /><applet load="1g2g" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1g2g" /> | caption="1g2g" /> | ||
'''MINIMAL CONFORMATION OF THE ALPHA-CONOTOXIN IMI FOR THE ALPHA7 NEURONAL NICOTINIC ACETYLCHOLINE RECEPTOR RECOGNITION'''<br /> | '''MINIMAL CONFORMATION OF THE ALPHA-CONOTOXIN IMI FOR THE ALPHA7 NEURONAL NICOTINIC ACETYLCHOLINE RECEPTOR RECOGNITION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The alpha-ImI conotoxin, a selective potent inhibitor of the mammalian | + | The alpha-ImI conotoxin, a selective potent inhibitor of the mammalian neuronal alpha7 nicotinic acetylcholine receptor (n-AchR), was shown by point mutation or by L-alanine scanning to display two regions essential for bioactivity: the active site Asp5-Pro6-Arg7 in the first loop and Trp10 in the second loop. The deletion of the Cys3,Cys12 disulfide bond in the alpha-ImI scaffold, e.g. peptide II, had no effect on its binding affinity. CD spectra, NMR studies and structure calculations were carried out on the wild type alpha-ImI, the weakest analog (R7A) and peptide II (equipotent to alpha-ImI) in order to point out the conformational differences between these compounds. Then, an attempt to correlate the conformational data and the affinity results was proposed. CD and NMR data were identical for the R7A analog and alpha-ImI, revealing the crucial functional role of the Arg7 side chain. On the other hand, the scaffold of the first loop in peptide II was shown by NMR to represent the minimal conformation for the optimal interaction of the toxin with the neuronal alpha7 n-AchR. Last, the beta-turn forming property of the 6th residue (Pro) in the active site of the alpha-ImI can be correlated with its affinity. |
==About this Structure== | ==About this Structure== | ||
| - | 1G2G is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1G2G is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G2G OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Jegou-Matheron, C.]] | [[Category: Jegou-Matheron, C.]] | ||
[[Category: Lamthanh, H.]] | [[Category: Lamthanh, H.]] | ||
| - | [[Category: Lancelin, J | + | [[Category: Lancelin, J M.]] |
[[Category: Menez, A.]] | [[Category: Menez, A.]] | ||
[[Category: Servent, D.]] | [[Category: Servent, D.]] | ||
| Line 21: | Line 21: | ||
[[Category: alpha-helix]] | [[Category: alpha-helix]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:45:19 2008'' |
Revision as of 10:45, 21 February 2008
|
MINIMAL CONFORMATION OF THE ALPHA-CONOTOXIN IMI FOR THE ALPHA7 NEURONAL NICOTINIC ACETYLCHOLINE RECEPTOR RECOGNITION
Overview
The alpha-ImI conotoxin, a selective potent inhibitor of the mammalian neuronal alpha7 nicotinic acetylcholine receptor (n-AchR), was shown by point mutation or by L-alanine scanning to display two regions essential for bioactivity: the active site Asp5-Pro6-Arg7 in the first loop and Trp10 in the second loop. The deletion of the Cys3,Cys12 disulfide bond in the alpha-ImI scaffold, e.g. peptide II, had no effect on its binding affinity. CD spectra, NMR studies and structure calculations were carried out on the wild type alpha-ImI, the weakest analog (R7A) and peptide II (equipotent to alpha-ImI) in order to point out the conformational differences between these compounds. Then, an attempt to correlate the conformational data and the affinity results was proposed. CD and NMR data were identical for the R7A analog and alpha-ImI, revealing the crucial functional role of the Arg7 side chain. On the other hand, the scaffold of the first loop in peptide II was shown by NMR to represent the minimal conformation for the optimal interaction of the toxin with the neuronal alpha7 n-AchR. Last, the beta-turn forming property of the 6th residue (Pro) in the active site of the alpha-ImI can be correlated with its affinity.
About this Structure
1G2G is a Single protein structure of sequence from [1] with as ligand. Full crystallographic information is available from OCA.
Reference
Minimal conformation of the alpha-conotoxin ImI for the alpha7 neuronal nicotinic acetylcholine receptor recognition: correlated CD, NMR and binding studies., Lamthanh H, Jegou-Matheron C, Servent D, Menez A, Lancelin JM, FEBS Lett. 1999 Jul 9;454(3):293-8. PMID:10431825
Page seeded by OCA on Thu Feb 21 12:45:19 2008
