Characterization of Botulinum Toxin Subtypes - Computational Modeling

该项目将使用LLNL(The LLNL)开发的同源建模和蛋白质分析算法 蛋白质管道)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 各种算法和模型的主干将使用我们的AS2TS建模包来创建。 已知的BONT/A和BONT/B全毒素和结构域的晶体结构将被用作模板。 末端区域和环、氨基酸插入和缺失以及模板模型的构建 将使用LGA程序执行结构比较。预测子类型集合 结构将与已知的毒素晶体结构进行比较，以确定最主要的亚型 可能表现出功能差异，这些信息将被用来识别哪些BONT变体 应结晶并在项目3中继续进行结构测定。每一亚型毒素 蛋白质序列也将在包含所有已知蛋白质序列的数据库中使用我们的 蛋白质管道以识别那些在任何其他蛋白质中没有发现的肽序列(签名)和 对子类型来说是唯一的。签名和突变将被映射到预测结构上，并且 检查以确定那些亚型特异性多肽签名，这些签名足够容易获得，可以用作 其他主要合作者开发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.