NMR STUDIES OF TRIPLE HELICAL PEPTIDES

描述：(摘自摘要)：本提案的长期目标 正在开发核磁共振技术来探测胶原样三元组的折叠 螺旋多肽，并使用所得到的结构和动力学信息 了解突变引起的胶原折叠疾病的基础 在三股螺旋结构中。用另一种氨基酸取代单一的甘氨酸 酸破坏胶原蛋白序列中的特征(Gly-X-Y)重复序列 三股螺旋结构并导致结缔组织疾病。有缺陷的折叠有 与疾病的病因学和折叠的性质有关 缺陷仍有待界定。一张详细的结构和运动图像 三螺旋的折叠路径将用核磁共振结构得到， 动力学和折叠实验。天然三聚体的平衡核磁共振研究 形式和展开的单体形式和动力学核磁共振实验，包括真实的 长寿命瞬变的时间折叠实验和表征 中级(S)，将提供折叠的详细视图 机制。天然序列折叠的序列依赖性检验 三螺旋将作为研究Gly/X突变如何导致 不正常的折叠。推测当地的氨基酸序列 围绕突变位点和被取代残基的身份是 决定三螺旋“错误折叠”的因素。核磁共振实验将是 应用于为序列特征建模而设计的类胶原肽 在突变部位发现，以确定折叠缺陷在 替换点和偏远位置。这些基于核磁共振的研究可能为 了解甘氨酸取代可导致 病理后果，并可能有助于阐明 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.