STUDIES ON THE RECEPTOR FOR NEUROTOXIN FROM BLACK WIDOW SPIDER VENOM. I. CHARACTERISATION OF MEMBRANE-BOUND AND SOLUBILIZED RECEPTOR STATES FROM BOVINE BRAIN

A. G. PETRENKO, O. G. SHAMOTIENKO, I. N. SURKOVA, V. A. KOVALENKO, E. V. GRISHIN

M. M. Shemyakin Institute of Bioorganic Chemistry, Academy of Sciences of the USSR, Moscow

Abstract: Iodine-125 labelled α-latrotoxin from the venom of Central Asia black widow spider Latrodectus mactans tredecimguttatus binds specifically to the bovine brain membrane receptor producing a stable slowly dissociating complex with K_d=1.6^-10°M and B_max=0.5 pmol/mg protein. Treatment of the complex with alkaline high-salt buffer induces reversible dissociation of the bound toxin. The antitoxin polyclonal antibody does not increase the dissociation rate of the bound toxin. Wheat germ lectin as well as concanavalin A inhibits the toxin binding to the membrane receptor. The receptor is solubilized with ionic and non-ionic detergents, and methods of latrotoxin binding assay are developed. The solubilized receptor is shown to retain high affinity to toxin, its binding activity being stable but critically dependent on the presence of calcium ions. Chromatographic properties of the receptor suggest its glycoprotein nature.

Russian Journal of Bioorganic Chemistry 1990, 16 (2):149-157

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