Nishiki T, Tokuyama Y, Kamata Y, Nemoto Y, Yoshida A, Sato K, Sekiguchi M, Takahashi M, Kozaki S
Department of Veterinary Science, College of Agriculture, University of Osaka Prefecture, Japan.
FEBS Lett. 1996 Jan 15;378(3):253-7. doi: 10.1016/0014-5793(95)01471-3.
125I-labeled botulinum type B neurotoxin was shown to bind specifically to recombinant rat synaptotagmins I and II. Binding required reconstitution of the recombinant proteins with gangliosides GT1b/GD1a. Scatchard plot analyses revealed a single class of binding site with dissociation constants of 0.23 and 2.3 nM for synaptotagmin II and synaptotagmin I, respectively, values very similar to those of the high- (0.4 nM) and low-affinity (4.1 nM) binding sites in synaptosomes. The high-affinity binding of neurotoxin to synaptosomes was specifically inhibited by a monoclonal antibody recognizing with the amino-terminal region of synaptotagmin II. These results suggest that this region of synaptotagmin II participates in the formation of the high-affinity toxin binding site by associating with specific gangliosides.
已证明125I标记的B型肉毒杆菌神经毒素能特异性结合重组大鼠突触结合蛋白I和II。结合需要重组蛋白与神经节苷脂GT1b/GD1a重构。Scatchard图分析显示存在一类结合位点，突触结合蛋白II和解突触结合蛋白I的解离常数分别为0.23和2.3 nM，这些值与突触体中高亲和力（0.4 nM）和低亲和力（4.1 nM）结合位点的值非常相似。识别突触结合蛋白II氨基末端区域的单克隆抗体可特异性抑制神经毒素与突触体的高亲和力结合。这些结果表明，突触结合蛋白II的该区域通过与特定神经节苷脂结合参与高亲和力毒素结合位点的形成。
