COOPERATIVE EFFECTS OF SMOOTH MUSCLE REGULATION

平滑肌调节的协同作用

基本信息

批准号：
6571148
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
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-12-01 至 2002-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6571148
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

项目摘要

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、原肌球蛋白、钙结合蛋白和肌球蛋白参与平滑肌的协同激活和松弛过程收缩。具体来说，我们的目标是：1）理解之间的区别与横纹肌相比，平滑肌的激活特性原肌球蛋白之间的端到端相互作用沿着细丝； 2)确定肌动球蛋白ATPase中的步骤受磷酸化影响的循环； 3）解释“latch”状态平滑肌，使肌肉可以长时间保持力量低磷酸化程度时没有大量 ATP 使用； 4）确定是否钙结合蛋白在平滑肌中的功能与肌钙蛋白类似。横纹肌并探索其他成分在调节中的作用过程。使用的方法包括 ATP 酶活性测量，荧光探针的动力学和平衡滴定蛋白质成分。从平滑肌中分离出原肌球蛋白亚型将使用突变的原肌球蛋白。根据获得的信息这些研究平滑肌调节的基本机制将是更好地理解，以便可以了解几种平滑肌异常特点。