ANTIBODIES AGAINST RAT-BRAIN VESICLE-ASSOCIATED MEMBRANE-PROTEIN (SYNAPTOBREVIN) PREVENT INHIBITION OF ACETYLCHOLINE-RELEASE BY TETANUS TOXIN OR BOTULINUM NEUROTOXIN TYPE-B

Tetanus and botulinum B neurotoxins are zinc endopeptidases that cleav e vesicle-associated membrane protein (VAMP or synaptobrevin) at a sin gle peptide bond. To test the possibility that in vivo also the toxin- induced blockade of neurotransmission is due to cleavage of VAMP, rat brain VAMP-specific antibodies were raised in rabbits. IgGs purified f rom one antiserum, which bind specifically to rat brain VAMP, also spe cifically recognize proteins from Aplysia californica in immunoblottin g. When injected into neurons in the buccal ganglion of Aplysia, these IgGs did not affect the release of acetylcholine but effectively prev ented the inhibitory action of both toxins on neurotransmitter release , thus indicating that the block of neurotransmission by these neuroto xins is consequent to the cleavage of VAMP or specific interaction wit h VAMP.