COOPERATIVE EFFECTS OF SMOOTH MUSCLE REGULATION

平滑肌调节的协同作用

• 批准号: 6434899
• 负责人: SHERWIN LEHRER
• 金额: $ 27.63万
• 依托单位: BOSTON BIOMEDICAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6434899
• 关键词: actins; adenosinetriphosphatase; animal tissue; caldesmon; chemical binding; chemical kinetics; conformation; enzyme activity; microfilaments; muscle contraction; myosins; phosphorylation; protein sequence; protein structure function; smooth muscle; striated muscles; tropomyosin; ultracentrifugation

The broad long-term objective of this project is to understand the couple interactions among the smooth muscle thin filament protein components, actin, tropomyosin, caldesmon and myosin that are involved in the cooperative activation and relaxation processes of smooth muscle contraction. Specifically, we aim to: 1) understand the difference between the activating properties of smooth muscle compared to striated muscle tropomyosin in terms of the end-to-end interactions between tropomyosins along the thin filament; 2) determine the steps in the actomyosin ATPase cycle that are affected by phosphorylation; 3) explain the "latch" state of smooth muscle, whereby the muscle can maintain force over long times without much ATP usage at low degrees of phosphorylation; 4) Determine if caldesmon functions in smooth muscle in an analogous manner to troponin in striated muscle and explore the role of other components in the regulation process. The methods to be used include ATPase activity measurements, kinetics and equilibrium titrations with fluorescence probes on the protein components. Tropomyosin isoforms isolated from smooth muscle and mutated tropomyosins will be used. With the information obtained from these studies the basic mechanisms of smooth muscle regulation will be better understood so that the several smooth muscle abnormalities can be characterized.

该项目的广泛长期目标是了解这对夫妇 平滑肌细丝蛋白成分之间的相互作用， 肌动蛋白，tropomyosin，caldesmon和肌球蛋白参与 平滑肌的合作激活和放松过程 收缩。具体来说，我们的目的是：1）了解 与横纹肌相比，平滑肌的激活特性 tropomyosin就tropomyosin之间的端到端相互作用而言 沿着细丝； 2）确定肌动蛋白ATPase的步骤 受磷酸化影响的循环； 3）解释“闩锁”状态 平滑肌，肌肉可以长期保持力 在低磷酸化的低度下没有太多的ATP使用； 4）确定是否 Caldesmon以平滑肌功能以类似的方式与肌钙蛋白相似 横纹肌肉并探索其他组件在调节中的作用 过程。要使用的方法包括ATPase活性测量， 动力学和平衡滴定在荧光探针上 蛋白质成分。从平滑肌和 将使用突变的肌动蛋白。从中获得的信息 这些研究的平滑肌调节基本机制将是 更好地理解，以便几种平滑肌异常 特征。