Nanomechanical studies of cells and biomolecules

摘要 本实验室的研究主要集中在力基机械的发展上。 生物分子和细胞成像的方法，并利用这些能力来研究 生物分子动力学和细胞力学中的若干问题。我们的成像方法 在探测化学、机械和电气特性方面提供新功能 从分子到细胞的生物系统。在生物分子成像中，我们关注的问题是 结构生物学可以在生理相关的条件下从直接成像中受益 像原子力显微镜(AFM)这样的机械方法具有优势。我们 目前正在开发一种基于AFM的方法来成像RNA/蛋白质复合体的动力学和 具有埃尺度分辨率的膜蛋白。在细胞力学研究中，我们最近 开发了一种细胞硬度成像方法，提供了前所未有的空间分辨率， 这有助于揭示细胞硬度的纳米模式，这是由Precision描述的 数学关系式。这些模式的存在并没有被当前的 细胞力学的定量模型。我们开发了一种新的模型，不仅解释了我们的 但也做出了新的可检验的预测，我们随后证实了这些预测。这些 分子和细胞研究决定了我们实验室目前的研究目标。论 在生物分子成像方面，我们未来五年的目标是将我们的技术发展到 利用Angstrom实现生理相关条件下的生物分子动力学成像 比例分辨率。目前，这样的高分辨率数据主要来自有效的方法 冷冻或结晶的样品，这阻碍了对生物分子动力学的观察。在……上面 在细胞力学方面，我们未来五年的目标包括进一步发展我们的细胞 机械模型，以解决不同测量结果之间的巨大差异 研究人员使用的方法。我们认为，差异不是由于技术问题造成的 各种方法，但由于对细胞接触机制的潜在假设， 这是一个概念性的问题。解决这一差异有助于更好地预测细胞力学 生理环境中的行为。我们还对研究机电产品感兴趣 并已经建立了一种独特适合的实验装置来 细胞膜中的机电耦合探针。我们的动力来自我们最近的 强耦合效应和耦合对离子选通的势效应的观测 通道和膜性细胞器的形态。总体而言，我们的研究愿景 计划是由纳米级机械相互作用在生物学中的重要作用制定的，我们 发展生物物理模型和实验能力以实现我们的愿景。

Abstract The research in our laboratory is centered on the development of force-based mechanical approaches to biomolecular and cellular imaging, and leveraging these capabilities to study a number of questions in biomolecular dynamics and cells mechanics. Our approach to imaging offers new capabilities in probing chemical, mechanical and electrical characteristics of biological systems from molecules to cells. In biomolecular imaging, we focus on problems in structural biology that can benefit from direct imaging in physiologically relevant conditions where mechanical approaches like atomic force microscopy (AFM) have advantages. We currently develop an AFM-based method to image dynamics of RNA/protein complexes and membrane proteins with Angstrom scale resolution. In cell mechanical studies, we recently developed a cell stiffness imaging method that provided unprecedented spatial resolution, which helped reveal nanoscale patterns in cell stiffness that are described by precise mathematical relationships. Existence of these patterns are not predicted by the current quantitative models of cell mechanics. We developed a new model that not only explained our findings, but also made new testable predictions that we subsequently confirmed. These molecular and cellular studies shape the current research goals in our laboratory. On the biomolecular imaging front, our goal for the next five years is to develop our technology to achieve imaging of biomolecular dynamics in physiologically relevant conditions with Angstrom- scale resolution. Currently, such high-resolution data is mainly coming from methods that work with frozen or crystallized samples, which prevent observations of biomolecular dynamics. On the cell mechanics front, our goals for the next five years include further developing our cell mechanical model to address a large discrepancy between results measured by different methods used by researchers. We believe the discrepancy is not due to technical problems of various methods, but rater due to underlying assumptions about contact mechanics of cells, that is, a conceptual issue. Addressing this discrepancy can help better predict cell mechanical behavior in physiological contexts. We are also interested in investigating electromechanical coupling in cell membranes and have already built a uniquely suited experimental setup to probe electromechanical coupling in cell membranes. We are motivated by our recent observations of strong coupling effects and potential effects of coupling on gating of ion channels and the morphology of membranous organelles. Overall, the vision of our research program is set by the important roles of nanoscale mechanical interactions in biology, and we develop biophysical models and experimental capabilities to realize our vision.