Marsal J, Ruiz-Montasell B, Blasi J, Moreira J E, Contreras D, Sugimori M, Llinás R
Universitat de Barcelona, Laboratori de Neurobiologia Cellular i Molecular, Departament de Biologia Cellular i Anatomia Patològica, Facultat de Medicina, Hospital de Bellvitge, Barcelona, Spain.
Proc Natl Acad Sci U S A. 1997 Dec 23;94(26):14871-6. doi: 10.1073/pnas.94.26.14871.
Electrophysiological, morphological, and biochemical approaches were combined to study the effect of the presynaptic injection of the light chain of botulinum toxin C1 into the squid giant synapse. Presynaptic injection was accompanied by synaptic block that occurred progressively as the toxin filled the presynaptic terminal. Neither the presynaptic action potential nor the Ca2+ currents in the presynaptic terminal were affected by the toxin. Biochemical analysis of syntaxin moiety in squid indicates that the light chain of botulinum toxin C1 lyses syntaxin in vitro, suggesting that this was the mechanism responsible for synaptic block. Ultrastructure of the injected synapses demonstrates an enormous increase in the number of presynaptic vesicles, suggesting that the release rather than the docking of vesicles is affected by biochemical lysing of the syntaxin molecule.
采用电生理学、形态学和生物化学方法相结合，研究了将肉毒杆菌毒素C1轻链突触前注射到枪乌贼巨大突触中的效应。突触前注射伴随着突触阻滞，随着毒素填充突触前终末，这种阻滞逐渐发生。毒素对突触前动作电位和突触前终末的Ca2+电流均无影响。对枪乌贼中Syntaxin部分的生化分析表明，肉毒杆菌毒素C1轻链在体外裂解Syntaxin，提示这是导致突触阻滞的机制。注射突触的超微结构显示突触前囊泡数量大幅增加，提示囊泡的释放而非对接受Syntaxin分子生化裂解的影响。
