NER: New Nanoscale Probes of Molecular Motors

NER：分子马达的新纳米探针国家纳米技术倡议的主要目标之一是发展纳米生物结构和过程的基本理解，如分子马达蛋白质的力学。分子马达蛋白是将化学能直接转化为机械功的酶。 这些蛋白质存在于大量的生物过程中，例如平滑肌和骨骼肌的收缩、细胞分裂以及细胞内和细胞膜上的物质运输。 最近在马达蛋白生物物理学的实验进展，导致了前所未有的洞察力的机制，单马达分子。例如，人们发现分子马达肌球蛋白会产生5纳米的离散步进，当受到大约5微微牛顿（pN）的力时会停止运动。尽管有了这些进展，但马达研究的一个主要障碍是无法解决工作冲程的作用，即马达的承载域向前运动。 PI提议使用新型光散射运动测定法在小至25纳秒的时间尺度上以亚纳米分辨率测量工作行程的动力学。 PI的方法还将提供对细胞和细胞运动的机械特性的洞察。

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.