The geometry of the ionic chànnel lumen formed by alpha-latroinsectotoxin from black widow spider venom in the bilayer lipid membranes.
The dependence of single channel conductance formed by alpha-latroinsectotoxin (alpha-LIT) from black widow spider venom in the planar phospholipid membrane on the hydrodynamic radii of different nonelectrolytes allowed to determine the geometry of alpha-LIT water lumen. It was found that the cis- and trans-entrances of alpha-LIT channel had the same effective radii of 0.55-0.58 nm. Relatively small conductance of alpha-LIT channel (23.5+3.7 pS) in a symmetrical membrane bathing solution of 100 mM KCl (pH 7.4) may result from the constriction inside the channel with apparent radius of 0.37 nm located 32.5% of channel length away from the cis-entrance.
Shatursky
Oleg Ya
OY
Department of Neurochemistry, Palladin Institute of Biochemistry, Leontovich Str, 9, 01601, Kiev, Ukraine. olegshatursky@biochem.kiev.ua
Volkova
Tatyana M
TM
Himmelreich
Nina H
NH
Grishin
Eugene V
EV
D000818:Animals; D001740:Black Widow Spider; D007473:Ion Channels / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology; D008051:Lipid Bilayers / Q000737:chemistry*; D008564:Membrane Potentials; D013111:Spider Venoms / Q000494:pharmacology*
D007473:Ion Channels; D008051:Lipid Bilayers; D013111:Spider Venoms; C074805:latroinsectotoxin; C038599:black widow spider venom