Structure of Peptides that Inhibit Pertussis Toxin-Receptor Binding

Spangler博士建议研究细菌毒素识别受体配体的分子基础，表征毒素受体结合部位的氨基酸残基和结构构象，并用构象受限的多肽模拟受体与毒素的相互作用。这一目标将部分通过计算机辅助分子模拟和最近被证明抑制百日咳毒素与受体类似物结合的特定多肽片段的实验结合研究来实现。为了启动这项研究并促进该项目的分子动力学部分，将需要这些多肽的三维结构信息，以及多肽结合特性的实验测定。拟议的初步研究将包括：(A)用计算方法预测多肽结构(B)用核磁共振方法求解多肽结构(C)用计算机模拟多肽与受体类似物的相互作用(D)实验验证多肽与受体类似物结合的能力，并阻止完整毒素的长距离结合目的是探索蛋白质-配体的相互作用，为理解和操纵分子识别在结合功能和蛋白质折叠方面提供合理的基础。所开发的技术和信息对于预测受体结构以辅助药物、除草剂或杀虫剂的设计；在疫苗设计中的抗原；或新的分子，如催化抗体和基于蛋白质的新的分子电子器件，可以通过蛋白质工程开发，为催化或电子转移提供模板方面具有价值。

Dr. Spangler proposes to study the molecular basis for recognition of receptor ligands by bacterial toxins, characterizing the amino acid residues and structural conformation of the toxin's receptor- binding site and modeling the receptor-toxin interaction with conformationally restrained peptides. This goal will be accomplished in part by a combination of computer-assisted molecular modeling and experimental binding studies of specific peptide fragments recently shown to inhibit pertussis toxin binding to receptor analogs. To initiate this study and facilitate the molecular dynamics portion of the project, three-dimensional structural information for these peptides will be required, coupled with an experimental determination of the binding characteristics of the peptides. The proposed preliminary study will consist of: (a) peptide structure prediction by computational methods (b) peptide structure solution by NMR methods (c) computer modeling of peptide interaction with receptor analogs (d) experimental verification of the ability of the peptides to bind receptor analogs and to block the binding of the intact toxin %%% The long range goal is to explore protein-ligand interactions and provide a rational basis for understanding and manipulating molecular recognition in both binding functions and protein folding. The techniques and information developed are of value in prediction of receptor structures to aid design of drugs, herbicides or pesticides; antigens in vaccine design; or novel molecules, such as catalytic antibodies and new molecular electronic devices based on proteins, that can be developed by protein engineering to provide a template for catalysis or electron transfer.