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, J.M.
(1999) FEBS Lett 454: 293-298
- PubMed: 10431825
- DOI: https://doi.org/10.1016/s0014-5793(99)00831-5
- Primary Citation of Related Structures:
- PubMed Abstract:
- A Nicotinic Acetylcholine Receptor Ligand of Unique Specificity, alpha-Conotoxin ImI
McIntosh, J.M., Yoshikami, D., Mahe, E., Nielsen, D.B., Rivier, J.E., Gray, W.R., Olivera, B.M.
(1994) J Biol Chem 269: 16733
- Functional Determinants by which Snake and Cone Snail Toxins Block the alpha 7 Neuronal Nicotinic Acetylcholine Receptors
Servent, D., Lamthanh, H., Antil, S., Bertrand, D., Corringer, P.J., Changeux, J.P., Menez, A.
(1998) J Physiol (Paris) 92: 107
- Identification of Residues in the Neuronal alpha7 Acetylcholine Receptor that Confer Selectivity for Conotoxin ImI
Quiram, P.A., Sine, S.M.
(1998) J Biol Chem 273: 11001
- NMR Spatial Structure of alpha-Conotoxin ImI Reveals a Common Scaffold in Snail and Snake Toxins Recognizing Neuronal Nicotinic Acetylcholine Receptors
Maslennikov, I.V., Shenkarev, Z.O., Zhmak, M.N., Ivanov, V.T., Methfessel, C., Tsetlin, V.I., Arseniev, A.S.
(1999) FEBS Lett 444: 275
- NMR Solution Structure of alpha-Conotoxin ImI and Comparison to other Conotoxins Specific for Neuronal Nicotinic Acetylcholine Receptors
Rogers, J.P., Luginbuhl, P., Shen, G.S., McCabe, R.T., Stevens, R.C., Wemmer, D.E.
(1999) Biochemistry 38: 3874
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 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.
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