Structure and Interactions of Gas Vesicles by SSNMR

通过 SSNMR 观察气体囊泡的结构和相互作用

• 批准号: 6601244
• 负责人: JUDITH HERZFELD
• 金额: $ 30.12万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2008-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6601244
• 关键词: Archaea; Halobacteriaceae; acidity /alkalinity; bacterial proteins; carbon; cell component structure /function; chemical models; gas; intermolecular interaction; membrane proteins; molecular biology; nitrogen; nuclear magnetic resonance spectroscopy; protein structure function; protonation; species difference; stable isotope; vesicle /vacuole

DESCRIPTION (provided by applicant): Despite great interest in their remarkable properties, and the considerable range of expertise brought to bear by several groups over many years, only the most general features of the structure of gas vesicles are known. However, recent developments now poise solid state NMR to provide numerous unique probes of the atomic details of the structure of the 7kDa monomer, gvpA, and its assembly into rigid, amyloid-like shells. Preliminary 13C and 15N spectra of uniformly labeled vesicles indicate that a combination of several isotope labeling strategies and an array of multidimensional correlation experiments should allow the full assignment of resonances and the determination of both intra-monomer and inter-monomer structural constraints. Ultimately, this information will allow the complete structure of the gas vesicle shell to be determined. Work will be carried out simultaneously on gas vesicles from the archae Halobacterium salinarum and the cyanobacterium Anabaena flos-aquaea. The parallel efforts will be synergistic because of the strong core homology between the gvpA's of the two species and the different isotope labeling strategies available in the two organisms. The parallel efforts will also be complimentary because of differences in overall vesicle morphology associated with differences in the N- and C-terminal domains of the two gvpA sequences. The role of electrostatics will be explored by identifying the cation displacements and protonation changes that induce vesicle collapse with decreasing pH. The response to salt will also be interesting since H. salinarum is a halophile and A. flos-aquaea is adapted to sweet water. Discovered structural details will shed light on the molecular basis of the morphology and rigidity of the vesicles, the prevention of water condensation within these gas permeable organelles, and the controlled assembly and disassembly of these amyloid-like aggregates.

描述（由申请人提供）：尽管对其出色的特性非常感兴趣，并且多年来由几个小组带来了相当多的专业知识，但仅知道气囊结构的最一般特征。但是，最近的发展现在可以使固态NMR保持众多独特的探针，以了解7KDA单体，GVPA的结构及其组装的原子细节，并将其组装成刚性的淀粉样蛋白样壳。均匀标记囊泡的初步13C和15N光谱表明，几种同位素标记策略和一系列多维相关实验的组合应允许共振的全部分配以及内部内部学者和内部经济体结构约束的确定。最终，此信息将允许确定气囊壳的完整结构。将同时对来自盐酸盐和蓝细菌Anabaena flos-aquaea的气囊泡同时进行。平行的努力将是协同作用的，因为这两个物种的GVPA与两个生物中可用的不同同位素标记策略之间具有强大的核心同源性。由于与两个GVPA序列的N-和C末端结构域的差异相关的总体囊泡形态差异，因此平行的努力也将是免费的。通过识别阳离子位移和质子化的变化，可以探索静电的作用，从而诱导囊泡塌陷随pH的降低。由于盐盐是卤素的，并且对盐的反应也将很有趣，并且A. flos-aquaea适用于甜水。发现的结构细节将阐明囊泡形态和刚性的分子基础，预防这些气体可渗透细胞器内的水冷凝，以及这些淀粉样蛋白样聚集体的受控组装和拆卸。