Proline-rich Sequences and Polyproline II Helix Formation

本项目的目的是确定富含脯氨酸的左手聚脯氨酸II（PPII）螺旋是如何形成的。 PPII螺旋在蛋白质中是常见的，并且通常在包括信号转导、细胞运动、转录和免疫应答的关键过程中发挥重要作用。 PPII螺旋参与两种结构作用（例如，如胶原蛋白所采用的）和分子识别（例如，由SH 3结构域介导的蛋白质-蛋白质相互作用）。 通常认为，许多富含脯氨酸的序列区（PRR）采用这种确认。 这个项目的目标是确定PPII螺旋的物理基础。 这将通过使用已知形成PPII螺旋的基于聚（脯氨酸）的宿主肽的系统性主客体实验来实现。 将采用实验和计算相结合的方法。 圆二色谱将用于测量主客体肽的平均PPII螺旋含量，以确定单个残基和残基对PPII螺旋形成的贡献。 高分辨率核磁共振光谱和分子动力学计算机模拟将被用来研究原子水平的相互作用，导致有利于或不利于PPII螺旋的形成。 从所有这些实验中获得的数据将结合起来，形成一个全面的原子级图片的PPII螺旋形成的PRR的。 该项目的结果将适用于从信号传导到转录再到细胞运动等众多关键生理过程的研究。 该项目奠定了必要的基础，为未来的研究蛋白质-蛋白质相互作用涉及PPII螺旋形成的PRR的。

The aim of this project is to determine how proline-rich left-handed polyproline II (PPII) helices form. PPII helices are common in proteins and often play vital roles in critical processes including signal transduction, cell motility, transcription and immune response. PPII helices are involved in both structural roles (e.g., as adopted by collagen) and molecular recognition (e.g., protein-protein interactions mediated by SH3 domains). It is commonly assumed that many proline-rich regions of sequence (PRR's) adopt this confirmation. The goal of this project is to determine the physical basis for PPII helices. This will be achieved via systematic host-guest experiments using a poly(proline)-based host peptide known to form a PPII helix. A combination of experimental and computational methods will be employed. Circular dichroism will be used to measure average PPII helical content of host-guest peptides in order to determine contributions of both individual residues and pairs of residues to the formation of PPII helices. High resolution nuclear magnetic resonance spectroscopy, and molecular dynamics computer simulations will be used to examine the atomic-level interactions that lead to the favoring or disfavoring PPII helix formation. The data obtained from all of these experiments will be combined to form a comprehensive atomic-level picture of PPII helix formation by PRR's. The results of this project will be applicable to studies of a multitude of critical physiological processes ranging from signal transduction to transcription to cell motility. This project lays essential groundwork for future studies of protein-protein interactions involving PPII helices formed by PRR's.