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: 6742443
• 负责人: JUDITH HERZFELD
• 金额: $ 30.22万
• 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/6742443
• 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）：尽管对它们的显着特性有很大的兴趣，并且多年来几个小组带来了相当大的专业知识范围，但只知道气泡结构的最一般特征。然而，最近的发展现在使固态NMR平衡，以提供7 kDa单体gvpA结构的原子细节及其组装成刚性淀粉样蛋白壳的许多独特探针。初步的13 C和15 N光谱的均匀标记的囊泡表明，几种同位素标记策略和多维相关性实验的阵列的组合应允许共振的充分分配和确定的单体内和单体间的结构约束。最终，这些信息将允许确定气泡壳的完整结构。将同时对古盐杆菌和蓝藻水华鱼腥藻的气泡进行研究。由于两个物种的gvpA之间的强核心同源性和两种生物体中可用的不同同位素标记策略，平行的努力将是协同的。平行的努力也将是互补的，因为与两个gvpA序列的N-和C-末端结构域的差异相关的总体囊泡形态的差异。静电的作用将探讨通过识别阳离子位移和质子化的变化，诱导囊泡崩溃与pH值下降。盐的响应也将是有趣的，因为H。salinarum是嗜盐菌，A. flos-aquaea适应于甜的水。发现的结构细节将揭示囊泡的形态和刚性的分子基础，防止这些透气性细胞器内的水冷凝，以及这些淀粉样聚集体的受控组装和拆卸。