Dipole moments of scorpion toxins direct the interaction towards small- or large-conductance Ca2+-activated K+ channels
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Ca2+-activated K+ channels consist of a large family of membrane proteins, among which two groups have been characterized by electrophysiological criteria, the small conductance (SK) and the large conductance (BK) Ca2+-activated K+ channels. Scorpion toxins that block K+ channels exhibit a common three-dimensional structure constituted of a short α-helix connected by disulfide bonds to a β-sheet. The leiurotoxin I (LTX1) related toxins interact specifically with the SK channel via basic residues of their α-helix, while the charybdotoxin (ChTX) family recognizes the BK channel with basic residues of their β-sheet. In an attempt to better understand the structure-activity relationships of these toxins and the characteristics of the electrostatic interactions with the receptor site, we investigated the electrostatic potential supported by natural toxins and a synthetic analogue to find out if it may help in understanding the molecular mechanisms involved in this peptide-protein interaction.
KeywordsElectrostatic interactions Iberiotoxin K+ channel blockers Leiurotoxin Peptide-receptor interaction Scorpion toxins
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- 1.Hille, B., Ionic Channels of Excitable Membranes, Sinauer, Sutherland, MA, U.S.A., 1992, 2nd ed.Google Scholar
- 4.Martin-Eauclaire, M.-F. and Couraud, F., Handbook of Neurotoxicology, Dyer, New York, NY, U.S.A., 1995, pp. 683.Google Scholar
- 18.Roussel, A. and Cambillau, C., In Silicon Graphics Geometry Partner Directory, Silicon Graphics, Mountain View, CA, U.S.A., 1989, p. 77.Google Scholar
- 19.Brünger, A.T., X-PLOR v3.1 Manual, Yale University, New Haven, CT, U.S.A., 1992.Google Scholar