Substructure and Communication in Myosin and Actin

肌球蛋白和肌动蛋白的亚结构和通讯

• 批准号: 9206739
• 负责人: Emil Reisler
• 金额: $ 48.5万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 1996-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9206739&HistoricalAwards=false
• 关键词: Substructure; Communication; Myosin; Actin

The contraction of skeletal, cardiac, and smooth muscles requires cyclic interactions between the two main muscle proteins, myosin and actin. The essential steps in these interactions include the activation of the myosin ATPase activity by actin and, according to prevalent views, conformational changes on one or both of these proteins. A major goal of the proposed research is to clarify the molecular basis of these events. To achieve aim, actin sites necessary for the activation of the myosin ATPase activity and the motility of actin filaments will be mapped. The experimental materials to be used in the mapping of functional sites on actin will include peptide antibodies, actin mutants, and modified actins. These materials will be used in the in vitro motility assays, and in biochemical and biophysical assays of actomyosin interactions. In another part of this program, the structural determinants of the essential steps in actomyosin interactions will be clarified by comparing the properties of monomeric and polymeric complexes of actin and myosin. Peptides, protein fragments, cross- linked protein complexes, peptide antibodies, and actin mutants will be used in this project. The role of specific sites on actin in actomyosin interactions will be assessed via chemical modifications, proteolytic digestions, fluorescence and light scattering measurements, and other measurements carried out on these materials. Additional insight into actomyosin interactions will be obtained by clarifying the mechanism of G-actin polymerization by myosin. %%% The proposed studies should lead to the elucidation of the basic mechanism of actomyosin interactions and thus, a better understanding of how the muscle functions and how chemical energy is transduced into work in biological systems.

骨骼肌、心肌和平滑肌的收缩需要 两种主要肌肉蛋白肌球蛋白 和肌动蛋白。 这些交互中的基本步骤包括 肌动蛋白激活肌球蛋白ATP酶活性，根据 流行的观点，构象变化对一个或两个这些 proteins. 拟议研究的一个主要目标是澄清 这些事件的分子基础。 为了达到目的，肌动蛋白位点 激活肌球蛋白ATP酶活性所必需的， 将绘制肌动蛋白丝的运动性。 实验 用于肌动蛋白功能位点定位的材料 将包括肽抗体、肌动蛋白突变体和修饰的 肌动蛋白 这些材料将用于体外运动 用于肌动球蛋白的生物化学和生物物理学测定 交互. 在这个项目的另一部分， 肌动球蛋白相互作用的基本步骤的决定因素将 通过比较单体和聚合物的性质来澄清 肌动蛋白和肌球蛋白的复合物。 肽，蛋白质片段，交叉- 连接的蛋白质复合物、肽抗体和肌动蛋白突变体 将用于该项目。 肌动蛋白上特定位点的作用 在肌动球蛋白的相互作用将通过化学 修饰，蛋白水解酶，荧光和光 散射测量和其他测量进行 这些材料。 对肌动球蛋白相互作用的进一步了解 通过阐明G-肌动蛋白的作用机制， 肌球蛋白聚合。 %%% 拟议的研究应导致阐明基本的 肌动球蛋白相互作用的机制，因此， 了解肌肉的功能和化学能量 被转化为生物系统中的工作。