NER: New Nanoscale Probes of Molecular Motors

国家纳米技术计划的主要目标之一是发展对纳米尺度生物结构和过程的基本理解，例如分子马达蛋白的力学。分子运动蛋白是将化学能直接转化为机械能的酶。这些蛋白质存在于大量的生物过程中，如平滑肌和骨骼肌的收缩、细胞分裂以及细胞内和细胞膜间的物质运输。最近运动蛋白生物物理学的实验进展使人们对单个运动分子的力学有了前所未有的了解。例如，研究发现，运动肌球蛋白分子会进行5nm的离散步进，并在大约5皮牛顿（pN）的力的作用下停止。尽管取得了这一进展，但电机研究的一个主要障碍是无法解决工作行程的动作，当电机的承载域向前移动时。PI建议使用一种新型光散射电机分析方法，以亚纳米分辨率在小至25纳秒的时间尺度上测量工作冲程的动力学。PI的方法还将提供对细胞和细胞运动的机械特性的深入了解。

NER:New Nanoscale Probes of Molecular MotorsOne of the major objectives of the National Nanotechnology Initiative is to develop a fundamental understanding of nanoscale biological structures and processes, such as the mechanics of molecular motor proteins. Molecular motor proteins are enzymes that convert chemical energy directly into mechanical work. These proteins are found in a vast array of biological processes, such as the contraction of smooth and skeletal muscle, cell division, and trafficking materials inside cells and across the cell membrane. Recent experimental advances in motor protein biophysics have resulted in unprecedented insight into the mechanics of single motor molecules. For instance, it was found that the molecular motor myosin makes discrete 5nm steps, and stalls when opposed by approximately 5 piconewtons (pN) of force.Despite this progress, a major obstacle in motor research has been theinability to resolve the action of the working stroke, when the load-bearing domain of the motor moves forward. The PI proposes to measure the dynamics of the working stroke with sub-nanometer resolution on timescales as small as 25 nanoseconds using a novel light-scattering motor assay. The PI's approach will also provide insight into the mechanical properties of cells and cell movement.