BIOPHYSICAL CHEMICAL STUDIES OF MUSCLE PROTEINS

我们计划继续进行目前的物理化学研究， 脊椎动物骨骼力产生的分子机制 肌肉. 在这些研究中，我们希望测试螺旋线圈模型 提出了在肌肉中产生力，并比较结果 根据经典的旋转十字架， 桥接机制 红外线碘光离解激光器 将用于加热纤维（约5摄氏度）低于1 μ sec和瞬态熔化之间的耦合（S-2 区域）僵硬的交叉桥梁和紧张局势的发展将 详细调查。 实验将在 离子条件下，S-2元素的严格桥是 通过与粗丝骨架结合而稳定， 在那里它们在不同的温度下从主链上释放出来 温度和肌节长度。 动力学常数和 力瞬变的振幅将与 活化纤维在各种环境条件下， 这两个国家试图证明存在或 缺乏可以区分 这两个机制。 我们还计划继续调查 在粗丝内的杆段的交联 甘油硬化纤维的核心，试图解耦力 在跨桥的S-2和S-1区域中产生。 的 特异性针对人肝癌细胞S-2区的多克隆抗体的作用 肌球蛋白对甘油化纤维收缩力的作用也受到抑制。 study. 这些实验，就像交联研究一样， 旨在确定是否调节S-2结合的一个 循环桥接到粗灯丝表面具有直接影响 关于武力生成 这些研究的长期目标是 了解肌肉收缩的过程， 水平 对这一过程的理解具有广泛的医学意义。 影响

We plan to continue current physico-chemical studies on the molecular mechanism of force-generation in vertebrate skeletal muscle. In these studies, we hope to test the helix-coil model proposed for force-generation in muscle and compare the results with those expected according to the classical rotating cross- bridge mechanism. An infrared, iodine photodissociation laser will be used to heat fibers (approximately 5 degrees C) under 1 mu sec and the coupling between transient melting in (the S-2 region of) rigor cross-bridges and the development of tension will be investigated in detail. Experiments will be carried out under ionic conditions where the S-2 elements of rigor bridges are stabilized by association with the thick filament backbone and where they are released from the backbone at various temperatures and sarcomere lengths. The kinetic constants and amplitudes of the force transients will be compared to those of activated fibers under a variety of environmental conditions in these two states in an attempt to demonstrate the presence or absence of common features which could distinguish between the two mechanisms. We also plan to continue our investigations of cross-linking of the rod segments within the thick filament core of glycerinated rigor fibers in an attempt to decouple force generation in the S-2 and S-1 regions of the cross-bridges. The effect of polyclonal antibodies specific to the S-2 region of myosin on contractile force in glycerinated fibers is also under study. These experiments, like the cross-linking studies, are designed to determine whether modulation of S-2 binding of a cycling bridge to the thick filament surface has a direct effect on force-generation. The long range goal of these studies is to understand the process of muscle contraction at a fundamental level. An understanding of this process has wide-ranging medical implications.