Light chain of tetanus toxin intracellularly inhibits acetylcholine release at neuro‐neuronal synapses, and its internalization is mediated by heavy chain
1989; Wiley; Volume: 253; Issue: 1-2 Linguagem: Inglês
10.1016/0014-5793(89)80926-3
ISSN1873-3468
AutoresSumiko Mochida, Bernard Poulain, Ulrich Weller, E. Habermann, L Tauc,
Tópico(s)Neuroscience and Neuropharmacology Research
ResumoThe ability of the two‐chain form of tetanus toxin (TeTx), its constituent light (LC) or heavy (HC) chains, and papain fragment to block evoked acetylcholine (ACh) release in the buccal ganglia of Aplysia californica was studied electrophysiologically. Extracellularly applied, TeTx or its B fragment (consisting of LC and β 2 , the amino‐terminal portion of HC) blocked ACh release, whereas LC, HC, or the β 2 fragment did not affect it. Toxicity was restored when LC was bath applied together with HC or the β 2 fragment. When injected into the presynaptic neuron, TeTx, the B fragment or LC, but not HC, induced inhibition of ACh release. These results indicate that the blockade of ACh release by TeTx is mimicked by intracellular action of LC, the internalization of which is mediated by the HC via its amino‐terminal moiety.
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