Selective enzymatic hydrolysis of nerve terminal phospholipids by beta-bungarotoxin: biochemical and morphological studies.
beta-Bungarotoxin, a presynaptic protein neurotoxin isolated from the venom of the snake Bungarus multicinctus, modifies release of neurotransmitter at the neuromuscular junction. The toxin has a potent phospholipase activity toward both natural membranes and phospholipid liposomes. Studies of ionic requirements and selective chemical modification demonstrate that beta-bungarotoxin can only modify synaptic transmission under conditions in which the phospholipase is active. Morphological studies on frog cutaneous pectoris neuromuscular junctions incubated with beta-toxin and horseradish peroxidase-conjugated beta-toxin support the hypothesis that beta-toxin specifically interacts with presynaptic plasma membranes and selectively hydrolyzes nerve terminal phospholipids.
D000818:Animals; D001001:Anura; D002038:Bungarotoxins / Q000494:pharmacology*; D005071:Evoked Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects*; D010743:Phospholipids / Q000378:metabolism*; D013570:Synaptic Membranes / Q000187:drug effects / Q000648:ultrastructure; D013997:Time Factors
D002038:Bungarotoxins; D010743:Phospholipids