Use of designed peptides to study folding and binding

描述(由申请人提供)：拟议的研究旨在为蛋白质的构象偏好、蛋白质中配体结合位点的产生以及蛋白质表面的识别提供新的见解。这些研究应该产生具有广泛意义的基本理解，并产生在基础研究中有价值的工具，或许在生物医学应用中也是如此。拟议的计划有四个具体目标。(1)我们将继续对β-折叠二级结构稳定性的来源进行生产性检查。我们最近开发了一个在水中折叠的平行Beta折叠的模型系统，我们将使用这个系统来探索平行Beta折叠偏好的起源。此外，我们将使用我们最近开发的一种新技术，主干硫酯交换(BTE)，来回答关于反平行β-折叠稳定性的基本问题。(2)我们将使用BTE和更传统的方法来研究控制三级结构稳定性的因素。一些小的蛋白质或蛋白质片段被选为这些研究的平台。(3)利用合理设计和噬菌体展示技术，将小分子的结合位点设计成最小长度的三级折叠单元。以这种方式产生的多肽可能会导致蛋白质的荧光标记、蛋白质工程的变构模块或新的传感器或催化剂。(4)探索非自然寡聚单元对蛋白质表面的识别。这些实验中确定的原则应该支持针对特定蛋白质-蛋白质相互作用的拮抗剂的开发，这是基础生物学研究和人类医学的重要目标。

DESCRIPTION (provided by applicant): The proposed research is aimed at providing new insights on the conformational preferences of proteins, the generation of ligand-binding sites in proteins, and the recognition of protein surfaces. These studies should produce fundamental understanding of broad significance and generate tools that are valuable in basic research and, perhaps, in biomedical applications. The proposed program has four specific goals. (1) We will continue a productive examination of the sources of beta-sheet secondary structure stability. We have recently developed a model system for parallel beta-sheet that folds in water, and we will use this system to probe the origins of parallel beta-sheet folding preferences. In addition, we will use a new technique that we have recently developed, backbone thioester exchange (BTE), to answer fundamental questions regarding antiparallel beta-sheet stability. (2) We will use BTE and more traditional methods to examine factors that control tertiary structural stability. Several small proteins or protein fragments have been selected as platforms for these studies. (3) We will try to engineer binding sites for small molecules into minimum-length tertiary folding units, using both rational design and phage display. The peptides generated in this way might lead to fluorescent tags for proteins, allosteric modules for protein engineering or new sensors or catalysts. (4) We will explore the recognition of protein surfaces by unnatural oligomeric units. Principles identified in these experiments should support the development of antagonists for specific protein-protein interactions, an important goal in basic biological research and human medicine.