CHEMOMECHANICS OF FAST AND SLOW SKELETAL MUSCLE CELLS

快和慢骨骼肌细胞的化学力学

• 批准号: 3154578
• 负责人: Martin J Kushmerick
• 金额: $ 11.92万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-06-01 至 1986-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3154578
• 关键词: adenosinetriphosphatase; bioenergetics; electrofocusing; enzyme substrate; gel electrophoresis; muscle cells; muscle contraction; muscle metabolism; myofibrils; phosphorylation; striated muscles

These experiments focus on the mechanical properties and ATPase activities of single striated muscle cells in order to study the regulation and chemomechanical properties of actomyosin interactions in a 3-dimensional intact, force-generating system. The first hypothesis to be tested is that phosphorylation of the 18-20 k dalton light chains, the so-called P-light chains or regulatory light chains, provides a mechanism for modulating actomyosin kinetics and so a mechanism to regulate velocity of shortening and ATPase activity when the system is activated by Ca++. The first set of experiments is designed to test hypotheses generated from our recent work on the role that myosin light phosphorylation plays in mammalian muscle energetics and mechanics wherein the postulated regulation has an apparent physiological role. The second hypothesis is that changes in the substrate (MgATP) or product (ADP and Pi) concentrations and their ratios change actomyosin chemical and mechanical kinetics in ways that test crossbridge models. The second set of experiments thus explores the details of crossbridge kinetics and is designed to generate information that allows a connection to be made between the biochemical properties of contractile proteins and muscle physiology. Detailed kinetic mechanisms for any phosphorylation effects found will also be examined by these methods. Rabbit fast skeletal muscle fibers (psoas) and slow skeletal muscle fibers (soleus) will be used in order to determine the generality or specificity of the results obtained and to define qualitative and quantitative differences that may occur among these two fundamental types of skeletal muscle fibers.

这些实验主要集中在机械性能和ATP酶活性 单个横纹肌细胞，以研究调节和 肌动球蛋白相互作用的化学机械性质 完整的力量生成系统 第一个要检验的假设是， 18-20 k道尔顿轻链的磷酸化，即所谓的P-轻链 链或调节轻链，提供了一种调节 肌动球蛋白动力学等调节缩短速度的机制 Ca ~（++）激活时，ATP酶活性升高。 第一组 实验的目的是测试从我们最近的工作产生的假设 肌球蛋白轻磷酸化在哺乳动物肌肉中的作用 能量学和力学，其中假设的调节具有明显的 生理作用。 第二个假设是基质的变化 （MgATP）或产物（ADP和Pi）浓度及其比值变化 肌动球蛋白化学和机械动力学的方式，测试横桥 模型 因此，第二组实验探索了 交叉桥动力学，并被设计为生成信息， 在收缩的生物化学特性之间建立联系 蛋白质和肌肉生理学。 详细的动力学机制， 还将通过这些方法检查所发现的磷酸化作用。 兔快骨骼肌纤维（腰大肌）和慢骨骼肌纤维 （soleus）将用于确定一般性或特异性 并确定定性和定量 这两种基本类型的骨骼之间可能存在的差异 肌肉纤维