Single Molecule Mechanical Studies of Actomyosin

描述(由申请人提供)：本计划的长期目标是 用单分子力学和荧光方法研究分子间的相互作用 将三磷酸腺苷产生的能量转化为机械功的一种机制 分子马达蛋白、肌动蛋白和肌球蛋白。单分子机械 与传统的肌肉测量相比，肌肉测量具有优势。 纤维在作用力、工作行程和单个纤维相互作用的动力学 带有肌动蛋白的跨桥可以直接测量。更好地理解 收缩机制是了解和理解 改善在病理条件下发生的变化，由 收缩功能有缺陷。肌球蛋白基因突变与家族性 肥厚性心肌病，这是导致心血管死亡的主要原因 年龄在40岁以下，最常见的先天性聋盲原因是 人类。该提案的具体目标是：1)确定机械设备 利用一系列三磷酸腺苷类似物改变桥梁的性能 (2)利用长寿命弱结合的机理 肌球蛋白中间体用于表征强电前中风状态；(3) 单分子机械法和荧光法相结合测定 产品投放与强制生产之间的时间关系。

Description (provided by applicant): The long term goals of this proposal are to use single molecule mechanical and fluorescence methods to study the mechanism by which the energy from ATP is converted to mechanical work by the molecular motor proteins, actin and myosin. Single molecule mechanical measurements have the advantage over traditional measurements with muscle fibers in that force, working stoke and kinetics of the interaction of a single cross-bridge with actin can be measured directly. A better understanding of the mechanism of contraction is an important step towards understanding and ameliorating the changes that occur in pathological conditions, resulting from defective contractility. Mutations in myosin are responsible for familial hypertropic cardiomyopathy, which is a major cause of cardiovascular death at ages under 40 and for the most common cause of congenital deaf-blind-ness in humans. Specific aims of the proposal are to: 1) determine the mechanical properties of cross-bridges by utilizing a series of ATP analogues that alter the rates of the hydrolysis mechanism; (2) utilize long-lived weakly-bound acto-myosin intermediates to characterize the prepower-stoke states; (3) combine single molecule mechanical and fluorescence methods to determine the temporal relationship between product release and force production.