Nanomechanical studies of cells and biomolecules

摘要 我们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的一些问题。我们的成像方法 提供了探测化学、机械和电气特性的新功能， 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 结构生物学可受益于生理相关条件下的直接成像 其中像原子力显微镜（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/蛋白质复合物的动力学， 膜蛋白质与埃尺度分辨率。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级模式， 数学关系。这些模式的存在不是由当前预测的 细胞力学的定量模型。我们开发了一个新的模型，不仅解释了我们的 研究结果，但也提出了新的可测试的预测，我们随后证实。这些 分子和细胞研究塑造了我们实验室目前的研究目标。上 在生物分子成像方面，我们未来五年的目标是发展我们的技术， 在生理相关条件下实现生物分子动力学成像， 尺度分辨率目前，这种高分辨率的数据主要来自于有效的方法， 冷冻或结晶样品，这会妨碍生物分子动力学的观察。对 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。我们相信，出现差异并非由于技术问题， 各种方法，但由于关于细胞接触力学的基本假设， 就是一个概念问题。解决这一差异可以帮助更好地预测细胞力学 生理环境中的行为。我们也有兴趣调查机电 细胞膜中的耦合，并已经建立了一个独特的适合的实验装置， 探测细胞膜中的机电耦合。我们的动机是我们最近 强耦合效应和耦合对离子门控的潜在影响的观察 通道和膜细胞器的形态。总的来说，我们研究的愿景 该计划是由纳米级机械相互作用在生物学中的重要作用，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.