NMR STUDIES OF TRIPLE HELICAL PEPTIDES

描述：（改编自摘要）：本提案的长期目标 是开发核磁共振技术来探测胶原样三联体的折叠， 螺旋肽，并使用由此产生的结构和动力学信息 了解突变引起的胶原蛋白折叠疾病的基础 在三螺旋结构中。单个Gly被另一个氨基取代 酸破坏胶原蛋白序列中的特征性（Gly-X-Y）重复序列 三螺旋结构并导致结缔组织疾病。折叠缺陷 与疾病的病因和折叠的性质有关 缺陷尚待确定。详细的结构和动力学图片的 三螺旋的折叠路径将通过NMR结构获得， 动力学和折叠实验。天然三聚体的平衡NMR研究 形式和未折叠的单体形式和动力学NMR实验，包括真实的 长寿命瞬态的时间折叠实验和特性 中间，将被组合以提供折叠的详细视图， 机制检查天然蛋白质折叠的序列依赖性 三螺旋将作为研究Gly/X突变如何导致 异常褶皱据推测，局部氨基酸序列 突变位点周围的氨基酸序列和取代的残基的身份是 三螺旋“错误折叠”的决定因素。核磁共振实验将是 应用于设计用于模拟序列特征的胶原蛋白样肽 在突变位点发现，以确定折叠缺陷的性质， 取代位点和远程位置。这些基于NMR的研究可能会为 了解Gly取代可能导致 病理后果，并可能揭示之间的关系， 折叠机制和临床表型。

DESCRIPTION: (adapted from abstract): The long term objectives of this proposal are to develop NMR techniques to probe the folding of collagen-like triple helical peptides, and to use the resulting structural and dynamical information to understand the basis for collagen folding diseases that arise from mutations in the triple helix motif. The substitution of a single Gly by another amino acid breaks the characteristic (Gly-X-Y) repeat in the sequence of the collagen triple helix and results in connective tissue disease. Defective folding has been implicated in the etiology of the disease and the nature of the folding defect remains to be defined. A detailed structural and kinetic picture of the folding pathway of the triple helix will be obtained with NMR structure, dynamics and folding experiments. Equilibrium NMR studies of the native trimer form and the unfolded monomer form and kinetic NMR experiments, including real time folding experiments and characterization of a long lived transient intermediate(s), will be combined to provide a detailed view of the folding mechanism. Examination of the sequence dependence of folding of the native triple helix will serve as a basis for studying how Gly/X mutations result in abnormal folding. It is hypothesized that the local amino acid sequence surrounding the mutation site and the identity of the substituted residue are determining factors in "misfolding" of the triple helix. NMR experiments will be applied to collagen-like peptides that are designed to model the sequence features found at mutation sites in order to define the nature of the folding defect at the substitution site and at remote positions. These NMR-based studies may pave the way to an understanding of the mechanism by which a Gly substitution can lead to pathological consequences and may shed light on the relationship between folding mechanisms and clinical phenotype.