Learning About Protein Unfolded States From Heterodimeric Fragment Complementation

从异二聚体片段互补中了解蛋白质未折叠状态

• 批准号: 0118252
• 负责人: Maria Luisa Tasayco
• 金额: $ 33万
• 依托单位: CUNY City College
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0118252&HistoricalAwards=false
• 关键词: Learning; About; Protein; Unfolded; States

This is a study of a family of complementary fragments from oxidized E. coli thioredoxin (Trx) and their heterodimeric reassemblies around different interfaces. The values of estimated buried surface from DSC studies of intrinsically unstructured protein fragments will be correlated with NMR studies of conformational preferences and rigidity of the backbone at the residue level. This project combines three areas of expertise (protein fragment complementation, calorimetry of proteins, and NMR analysis of structure and dynamics of proteins) and centers on two main hypotheses: (1) Isolated Trx fragments which comprise the regions of the native 2 and 4 strands have substantial nonlocal interactions between them, while remaining intrinsically unstructured. (2) The differences in delta G of folding/binding among the different heterodimeric reassemblies are mainly due to differences in the degree of folding and rigidity in the isolated fragments. In order to test these hypotheses, the delta G of folding/binding and low-resolution structural characterization of the initial and final states for a family of complementary fragments will be determined. High sensitivity DSC studies of selected isolated fragments and heterodimeric reassemblies will be undertaken, and NMR studies of the structures of the initial and final states of selected complementary fragments will be done to study the dynamics of such a selected pair in both states. The long-term objective of these studies is to characterize the conformational space of the unfolded state of proteins and understand protein-protein interactions covering a range of affinities and degree of folding associated with binding through a synergistic interaction between experimenation and theory.

这是对来自氧化的大肠杆菌硫氧还蛋白（TRX）及其异二聚体重新组合不同界面周围的一个互补片段家族的研究。 来自内在非结构化蛋白质片段的DSC研究中估计的埋入表面的值将与残基水平上骨架构象偏好和刚性刚度的NMR研究相关。该项目结合了三个专业知识（蛋白质片段互补，蛋白质的量热法以及蛋白质结构和动力学的NMR分析），并以两个主要假设为中心：（1）构成天然2和4链区域的孤立TRX片段它们之间存在实质性的非局部相互作用，同时保持本质上的非结构化。 （2）不同异二聚体重新组件之间折叠/结合的折叠/结合的差异主要是由于孤立片段中折叠程度和刚性程度的差异。 为了检验这些假设，将确定互补片段家族的初始状态和最终状态的折叠/结合和低分辨率结构表征的三角洲。 将进行对选定的孤立片段和异二聚体重新组合的高灵敏度DSC研究，并将完成对所选互补片段的初始和最终状态结构的NMR研究，以研究两种状态下这种选定对的动态。这些研究的长期目的是表征蛋白质未折叠状态的构象空间，并了解蛋白质 - 蛋白质相互作用，涵盖了通过实验和理论之间的协同相互作用而与结合相关的一系列亲和力和折叠程度。