PROXIMITY RELATIONSHIPS AMONG MUSCLE PROTEINS

本项目的长期目标是阐明 1)骨骼肌收缩过程中的能量转换，2） 通过钙离子调节骨骼肌收缩。 由于这两 这些过程是正常肌肉组织功能的基础， 这项工作可能有助于深入了解病理性肌肉的本质， 条件 这一目标将通过确定空间 四种主要收缩蛋白质之间的关系：肌球蛋白，肌动蛋白， 原肌球蛋白和肌钙蛋白。 此外，这些空间关系 随着肌肉的功能状态（放松、激活或处于 严格性）将被检查。 由此获得的信息将用于 重建肌肉收缩过程中发生的分子事件， 其规定。 主要地，将使用两种技术来确定空间 关系：激发能转移，光化学 交联 原肌球蛋白和三个 肌钙蛋白的亚基将由激发能量转移决定 测量. 同时，界面处的氨基酸残基 将使用光交联和肽识别蛋白质之间的 分析技术。 将使用从这些研究中获得的信息 构建肌钙蛋白原肌球蛋白的三维模型 复杂. 以类似的方式，原肌球蛋白， 肌动蛋白和肌球蛋白将被确定，和之间的相互作用界面 这些蛋白质被鉴定出来。 这将产生关于 肌球蛋白、肌动蛋白、原肌球蛋白复合物中的原肌球蛋白和接触区 肌球蛋白和肌动蛋白之间的联系

The long-term objective of this project is to elucidate the mechanisms for 1) transduction of energy during contraction of skeletal muscle, 2) the regulation of skeletal muscle contraction by calcium ions. Since these two processes are fundamental to the functioning of normal muscle tissue, this work may provide insight into the nature of pathological muscle conditions. This objective will be achieved by determining the spatial relationships among the four major contractile proteins: myosin, actin, tropomyosin and troponin. Furthermore, how these spatial relationships change with the functional state of muscle (relaxed, activated, or in rigor) will be examined. Information so derived will be used to reconstruct the molecular events that occur during muscle contraction and its regulation. Principally, two techniques will be used to determine spatial relationships: excitation energy transfer, and photochemical crosslinking. The distances between sites in tropomyosin and in the three subunits of troponin will be determined by excitation energy transfer measurements. Simultaneously, amino acid residues at the interfaces between the proteins will be identified using photocrosslinking and peptide analysis techniques. Information derived from these studies will be used to construct a three-dimensional model for the troponin.tropomyosin complex. In a similar fashion, distances between sites in tropomyosin, actin and myosin will be determined, and the interaction interfaces between these proteins identified. This will yield information on the location of tropomyosin in the myosin.actin.tropomyosin complex, and the contact region between myosin and actin.