[Solubilization of beta-bungarotoxin-binding protein from rat diaphragm and inhibition of its binding by some other presynaptic neurotoxins].
The mechanism of the transmitter release-blocking action of beta-bungarotoxin at neuromuscular junctions is probably related to the binding of the toxin to a presynaptic voltage-dependent K+ channel. In this paper we report the solubilization of beta-bungarotoxin-binding protein from rat diaphragm membrane preparations with Triton X-100. The specific binding activities of the detergent extracts are 200-400 fmol/mg of protein, and the yields are about 50%-70%. The binding of 125I-beta-bungarotoxin to the extracts could be completely inhibited by dendrotoxin, with an IC50 of about 8 x 10(-8) mol.L. Another beta-neurotoxin, beta-agkistrodotoxin, however, could not inhibit the 125I-beta-bungarotoxin binding at all. This indicates that the acting sites of beta-agkistrodotoxin on the presynaptic membranes are different from those of beta-bungarotoxin.
Shen
G G
GG
Shanghai Institute of Physiology, Chinese Academy of Sciences.
Zhuo
X L
XL
Zhang
X M
XM
Xu
K
K
D000818:Animals; D001665:Binding Sites; D002038:Bungarotoxins / Q000302:isolation & purification* / Q000378:metabolism; D002352:Carrier Proteins / Q000302:isolation & purification* / Q000378:metabolism; D003435:Crotalid Venoms / Q000494:pharmacology; D003964:Diaphragm / Q000378:metabolism; D004546:Elapid Venoms / Q000494:pharmacology; D009469:Neuromuscular Junction; D009498:Neurotoxins / Q000494:pharmacology; D011092:Polyethylene Glycols; D017729:Presynaptic Terminals; D051381:Rats; D017207:Rats, Sprague-Dawley
D002038:Bungarotoxins; D002352:Carrier Proteins; D003435:Crotalid Venoms; D004546:Elapid Venoms; D009498:Neurotoxins; C041451:beta-bungarotoxin binding protein, rat; D011092:Polyethylene Glycols; C020273:dendrotoxin; C070121:beta-agkistrodotoxin