Dynamic Properties of Bacterial Adhesions

细菌粘附的动态特性

• 批准号: 6768774
• 负责人: EVGENI Veniaminovic SOKURENKO
• 金额: $ 57.72万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-15 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6768774
• 关键词: Enterobacteriaceae; Vibrio; X ray crystallography; adhesin; adhesions; atomic force microscopy; bacteria infection mechanism; fluorescence resonance energy transfer; gene mutation; ligands; mechanical stress; protein binding; protein structure function; receptor binding

DESCRIPTION (provided by the applicant): The main goal of the proposal is to develop a comprehensive structural picture of how mechanical force affects the functional state of microbial adhesions. Specific adhesive proteins enable bacteria to recognize ligands leading to the adhesion and colonization of various living hosts or environmental niches, and finally infection. A growing number of experimental observations indicate that mechanical forces generated by shear-flow of body fluids are modulating the affinity and selectivity of adhesins to their ligands. In order to test the extent to which mechanical forces may alter the structure and thus the functional states of adhesins, we propose to characterize the dynamic properties of the most common type of bacterial adhesin - FimH -that is a lectin-like adhesive subunit of type 1 (mannose-sensitive) fimbria of Enterobacteria and Vibrio. In the course of our preliminary studies we have identified distinct structural variants of the Escherichia coli FimH adhesin where shear-flow can induce their preferential binding to target cells, obviously by switching their specificity between the mono-mannoside and tri-mannoside receptors. To develop structural hypotheses how mechanical forces acting on the binding site may affect the tertiary structure of FimH, we have been and will be conducting steered molecular dynamics simulations in which tension is applied between the receptor-binding residues and the C-terminal end of the FimH lectin domain. Deriving a comprehensive understanding of the structure-function relationship of adhesins under static and dynamic conditions requires that molecular biology tools are employed in concert with X-ray crystallography and novel powerful nano-analytical tools to probe, characterize and simulate non-equilibrium protein structures as they relate to function.

描述（由申请人提供）：该提案的主要目的是制定全面的结构图，即机械力如何影响微生物粘连的功能状态。特定的粘合剂蛋白使细菌能够识别配体，从而导致各种宿主或环境壁ni的粘附和定植，最后感染。越来越多的实验观察结果表明，体液的剪切流产生的机械力正在调节粘附素对配体的亲和力和选择性。为了测试机械力可以改变结构并因此是粘附素的功能状态的程度，我们建议表征最常见的细菌粘附素类型的动态特性-FIMH -FIMH -AT是一种类型1型凝集素的粘合剂亚基（mannose敏感性）肠杆菌和纤维的粘膜。在初步研究的过程中，我们已经确定了大肠杆菌FIMH粘附蛋白的不同结构变异，其中剪切流可以通过在单甘露糖苷和三雄素糖苷受体之间切换其特异性来诱导它们与靶细胞的优先结合。为了发展结构假设，如何在结合位点上作用在结合位点上可能影响FIMH的三级结构，我们一直并将进行转向的分子动力学模拟，其中在受体结合残基和FIMH ltectin域的C末端之间应用张力。在静态和动态条件下，对粘附素的结构功能关系有全面的了解，要求分子生物学工具与X射线晶体学和新型强大的纳米分析工具一起使用，以探测，表征和模拟与功能相关的非平衡蛋白结构。