HETEROBIFUNCTIONAL CROSSLINKERS: EFFECT ON THIN FILAMENT

钙离子对脊椎动物横纹肌收缩的调节 近年来一直是一个相当感兴趣的话题。这个 初始结构、生化和结构信息 关于细丝导致了立体的发展 原肌球蛋白物理作用模式的阻断理论。 原肌球蛋白相对于肌动蛋白运动的证据 肌肉的钙激活在X射线中是有良好基础的 衍射，电子显微镜重建，以及在一些 生化和生物物理探头研究。然而，一开始 随着Bremel和Weber的发现增强了 调节细丝，其他一些研究表明 钙离子的实际作用涉及到激活的钙离子的动力学。 ATPase反应以及肌球蛋白的性质，可能是 通过酶促的磷酸化轻链 分子的活性区域。这一日益复杂的 调节机制规定原肌球蛋白在 监管过程需要更深入地研究。 建议调查一些相对的使用情况 新型异型双功能交联剂的研究 它们对重组薄层调控能力的影响 细丝。将尝试使原肌球蛋白和 肌动蛋白使用这些试剂试图使肌动蛋白在较少的 比以前用General完成的更严格的方式 交联剂，如丙醛。结果是 原肌球蛋白与肌动蛋白的分子内交联 还将研究细丝的重组，作为一种 为了自己的利益和控制权。在这项初步研究中， 肌球蛋白ATPase活性的变化与超沉淀 将会被检查。一组初选的结果 并进行了调查研究。

The regulation of vertebrate striated muscle contraction by Ca++ has been a topic of considerable interest in recent years. The initial structural biochemical and structural information concerning the thin filament led to the development of the steric blocking theory for the physical mode of action of tropomyosin. The evidence for the movement of tropomyosin relative to actin on Ca++ activation of muscle is well grounded in x-ray diffraction, electron microscopic reconstructions, and in some biochemical and biophysical probe studies. However beginning with Bremel and Weber's discovery of potentiation of the regulated thin filament, a number of other studies indicate that the actual effects of Ca++ involve the kinetics of the activated ATPase reaction as well as the properties of myosin, probably through the phosporylatable light chain of the enzymatically active regions of the molecule. This increasing complexity of the regulation mechanism mandates that the role of tropomyosin in the regulatory process be more intensively studied. It is proposed to investigate the use of a number of relatively newly developed heterobifunctional crosslinking reagents to study their effects on the regulatory ability of reconstituted thin filaments. Attempts will be made to crosslink tropomyosin and actin using these reagents to try to immobilize actin in a less stringent way than has been accomplished before with general crosslinking reagents such as gluteraldehyde. The results of intramolecular crosslinking of tropomyosin and actin before reconstitution of the thin filament will also be studied, both as a control and for its own interest. In this preliminary study the alterations in the activated myosin ATPase and superpercipitation will be examined. The results of one set of preliminary investigations is presented.