NMR studies of collagen model peptides and their interactions with collagen recep

描述（由申请人提供）：胶原蛋白是细胞外基质中最丰富的蛋白质之一，在人体中提供结构完整性，并负责与细胞和其他基质分子的多重相互作用。许多常见疾病，如关节炎、糖尿病和癌症都涉及到胶原蛋白的异常调节或反应性，某些胶原基因疾病会导致结缔组织疾病或主动脉瘤。本提案的目的是发展对胶原配体与其受体相互作用的机制理解，并了解成骨不全症（OI）的分子基础，成骨不全症是一种导致骨质脆性的遗传疾病。我们建议使用基于核磁共振结合计算，生物物理方法和体外功能分析的综合方法来提供独特的结构和动态洞察这些问题。该提案的具体目标包括：1)表征整合素I结构域与胶原蛋白之间相互作用的结构和动力学；2)确定Gly突变导致胶原疾病的序列依赖性和分子机制：OI表型的预测；3)表征基质金属蛋白酶（MMPs）和整合素i结构域受体的相互作用，这些受体具有在结合区域或附近含有不完美（GXY）n序列的三螺旋基序。为了实现这些目标，我们将开发一些新的方法，旨在1)实现更好的胶原模型肽的结构和动态表征；这些是长各向异性分子，难以通过标准协议和集成来表征

DESCRIPTION (provided by applicant): Collagen, one of the most abundant proteins of the extracellular matrix, provides structural integrity in the human body and is responsible for multiple interactions with cells and other matrix molecules. Many common diseases, such as arthritis, diabetes, and cancer involve abnormal regulation or reactivity of collagen and certain collagen genetic diseases result in connective tissue disease or aortic aneurism. The objective of this proposal is to develop a mechanistic understanding of the interactions of the collagen ligand with its receptors and to understand the molecular basis of Osteogenesis Imperfecta (OI), a genetic disease that results in brittle bones. We propose to use an integrated approach based on NMR in conjunction with computational, biophysical methods, and in vitro functional assays to provide unique structural and dynamic insight these questions. The specific aims of the proposal include 1) characterizing the structure and dynamics of the interactions between the integrin I domain and collagen; 2) defining the sequence dependence and molecular mechanism of Gly mutations leading to collagen diseases: prediction of OI phenotype and 3) characterizing interactions of matrix metalloproteinases (MMPs) and integrin I-domain receptors with triple helical motifs that contain imperfect (GXY)n sequences at, or near, the binding regions. In order to achieve these aims we will develop some novel methodology designed to 1) achieve better structural and dynamic characterization of the collagen model peptides; these are long anisotropic molecules that are difficult to characterize by standard protocols and integration of NMR and MD simulations will provide a new approach for investigation of these unusual systems. 2) Using statistical approaches, develop consensus sequence patterns that define lethal and nonlethal phenotypes in OI; these will be used to begin to establish predictions of phenotype based on sequence and conformational fluctuations. The biomedical importance of collagen has led to increasing interest in the structural and biological role of this protein makin the collagen triple helix an extremely important target for probing sequence-structure-function relationships and for understanding the molecular basis of collagen/receptor biological interactions. Characterizing the collagen triple helix conformation and dynamics alone, and in combination with its binding partners, will help understand its role in disease and ligand recognition, and aid in drug discovery programs.