1. SGTx1, a Kv Channel Gating-Modifier Toxin, Binds to the Interfacial Region of Lipid Bilayers
- Author
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Daniele Bemporad, Mark S.P. Sansom, Chze Ling Wee, Zara A. Sands, and David J. Gavaghan
- Subjects
Models, Molecular ,Time Factors ,Biophysical Letters ,Protein Conformation ,Lipid Bilayers ,Static Electricity ,Biophysics ,Analytical chemistry ,Spider Venoms ,Model lipid bilayer ,010402 general chemistry ,01 natural sciences ,03 medical and health sciences ,Orientations of Proteins in Membranes database ,Membrane fluidity ,Animals ,Lipid bilayer phase behavior ,Lipid bilayer ,030304 developmental biology ,0303 health sciences ,Chemistry ,Bilayer ,Cell Membrane ,Lipid bilayer fusion ,Water ,Biological membrane ,Phosphatidylglycerols ,Lipids ,0104 chemical sciences ,Potassium Channels, Voltage-Gated ,Phosphatidylcholines ,lipids (amino acids, peptides, and proteins) - Abstract
SGTx1 is a gating-modifier toxin that has been shown to inhibit the voltage-gated potassium channel Kv2.1. SGTx1 is thought to bind to the S3b-S4a region of the voltage-sensor, and is believed to alter the energetics of gating. Gating-modifier toxins such as SGTx1 are of interest as they can be used to probe the structure and dynamics of their target channels. Although there are experimental data for SGTx1, its interaction with lipid bilayer membranes remains to be characterized. We performed atomistic and coarse-grained molecular dynamics simulations to study the interaction of SGTx1 with a POPC and a 3:1 POPE/POPG lipid bilayer membrane. We reveal the preferential partitioning of SGTx1 into the water/membrane interface of the bilayer. We also show that electrostatic interactions between the charged residues of SGTx1 and the lipid headgroups play an important role in stabilizing SGTx1 in a bilayer environment. © 2007 by the Biophysical Society.
- Published
- 2006