BLOCKAGE OF TOXIN-CELL INTERACTIONS BY OLIGOSACCHARIDES

这项提案的总体目标是了解 神经毒素与它们的靶细胞相互作用，并利用这一知识 开发有效的毒素-细胞相互作用的抑制剂。三 将对肉毒毒素(A、B和E)进行研究，以确定 用一种毒素(肉毒杆菌毒素A)所做的观察可能会有一般的 适用性。如果肉毒杆菌毒素的表现类似，比较 会对破伤风毒素做出哪些相似之处的判断 在这两类神经毒素之间。具体地说，对 肉毒毒素B和E与G1b神经节苷脂及其衍生物的结合 它将被执行。结果将与所获得的结果进行比较 肉毒杆菌毒素A和破伤风毒素。越来越多的证据表明 神经节苷脂可能不是这些细胞表面唯一的受体 神经毒素。在最近的研究中，我们发现肉毒杆菌毒素A， 它的重链和重链的羧基末端一半结合在一起 突触体蛋白。破伤风毒素也附着在突触体上 蛋白质，但它必须与GT1b预先孵育才能与 蛋白。这两种神经毒素所附着的蛋白质具有明显的 分子量约为77 kDa，是糖基化的。 提纯和鉴定近似kDa的实验设计 蛋白质会继续，而毒素附着的部位(S)会 将被确认为神经毒素中负责 结合，并在体外实验中设计鉴定功能 特定交互的各个方面。

The overall goal of this proposal is to understand how clostridial neurotoxins interact with their target cells and to use this knowledge to develop effective inhibitors of the toxin-cell interaction. Three botulinum toxins (A,B and E) will be studied to determine whether observations made with one toxin (botulinum toxin A) might have general applicability. If the botulinum toxins behave similarly, comparisons will be made to tetanus toxin to determine what similarities exist between the two classes of neurotoxins. Specifically, studies of the binding of botulinum toxins B and E to G1b gangliosides and derivatives thereof will be carried out. Results will be compared to those obtained for botulinum toxin A and tetanus toxin. Accumulating evidence suggests that gangliosides may not be the only cell surface receptor for these neurotoxins. In recent studies, we have found that botulinum toxin A, its heavy chain and the carboxy terminal half of the heavy chain bind to synaptosomal proteins. Tetanus toxin also adhered to synaptosomal proteins but it had to be preincubated with GT1b in order to bind to protein. The protein adhered to by both neurotoxins has an apparent molecular weight of approximately 77 kDa and is glycosylated. Experiments designed to purify and characterize the approximately kDa protein will be continued, and the site(s) adhered to by the toxin will be identified as will the portion of the neurotoxin responsible for the binding, and in in vitro experiments designed to identify the functional aspects of specific interactions.