title: SGTx1, a Kv channel gating-modifier toxin, binds to the interfacial region of lipid bilayers.
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.
authors.forename: Chze Ling
authors.initials: CL
authors.lastname: Wee
authors.forename: Daniele
authors.initials: D
authors.lastname: Bemporad
authors.forename: Zara A
authors.initials: ZA
authors.lastname: Sands
authors.forename: David
authors.initials: D
authors.lastname: Gavaghan
authors.forename: Mark S P
authors.initials: MS
authors.lastname: Sansom
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D008958:Models, Molecular; D010713:Phosphatidylcholines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D024642:Potassium Channels, Voltage-Gated / Q000187:drug effects* / Q000378:metabolism*; D011487:Protein Conformation; D013111:Spider Venoms / Q000378:metabolism / Q000494:pharmacology*; D055672:Static Electricity; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D008055:Lipids; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D024642:Potassium Channels, Voltage-Gated; C400227:SGTx1 toxin; D013111:Spider Venoms; D014867:Water; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol; C028694:1-palmitoyl-2-oleoylphosphatidylcholine