Characterization of Botulinum Toxin Subtypes - Computational Modeling

该项目将采用LLNL开发的同源建模和蛋白质分析算法（ Protein Pipeline）来预测和分析每种肉毒杆菌神经毒素（BoNT）亚型的结构， 项目1中确定的蛋白质序列。序列结构比对将使用 各种算法，模型的主干将使用我们的AS 2 TS建模包创建。 BoNT/A和BoNT/B全毒素和结构域的已知晶体结构将用作模板。 末端区域和环的构建、氨基酸插入和缺失以及模板模型 将使用LGA程序进行结构比较。预测亚型的集合 将其结构与已知的毒素晶体结构进行比较，以鉴定那些最常见的亚型。 可能表现出功能差异，这些信息将用于识别哪些BoNT变体 在项目3的结构确定中，应将其具体化并加以继承。各亚型毒素 蛋白质序列也将对包含所有已知蛋白质序列的数据库使用我们的 蛋白质管道，以确定那些肽序列（签名），没有发现在任何其他蛋白质和 都是亚型独有的签名和突变将被映射到预测的结构上， 检查以鉴定那些亚型特异性肽特征，其足够可接近以用作 其他关键合作者开发BoNT亚型特异性抗体的表位。

This project will employ homology modeling and protein analysis algorithms developed at LLNL (the Protein Pipeline) to predict and analyze the structures of each botulinum neurotoxin (BoNT) subtype using the sequences of the proteins determined in Project 1. Sequence-structure alignments will be generated using a variety of algorithms, and the backbone of the model will be created using our AS2TS modeling package. The known crystal structures of the BoNT/A and BoNT/B holotoxins and domains will be used as templates. The construction of the terminal regions and loops, ammo acid insertions and deletions, and template-model structure comparisons will be performed using the LGA program. The collection of predicted subtype structures will be compared with the known toxin crystal structures to identify those subtypes that are most likely to exhibit functional differences, and this information will be used to identify which BoNT variants should be crystallized and carried forward for structure determination in Project 3. Each subtype toxin protein sequence will also be blasted against a database containing all known protein sequences using our Protein Pipeline to identify those peptide sequences (signatures) that are not found in any other protein and are unique to the subtype. The signatures and mutations will be mapped onto the predicted structures and examined to identify those subtype-specific peptide signatures that are sufficiently accessible to be used as epitopes for the development of BoNT subtype-specific antibodies by other key collaborators.