COOPERATIVE EFFECTS OF SMOOTH MUSCLE REGULATION

这个项目的长期目标是了解这对夫妇 平滑肌细丝蛋白组分之间的相互作用， 肌动蛋白、原肌球蛋白、钙调素和肌球蛋白参与 平滑肌的协同激活和松弛过程 收缩。具体地说，我们的目标是：1)了解 平滑肌与横纹肌的激活特性比较 原肌球蛋白与原肌球蛋白之间的端到端相互作用 2)测定肌动球蛋白ATPase的步骤 受磷酸化影响的循环；3)解释“闩锁”状态 指平滑的肌肉，借此肌肉可以长时间保持力量 在低程度磷酸化的情况下不使用太多的ATP；4)确定 钙蛋白在平滑肌中的作用类似于肌钙蛋白。 并探讨其他成分在调节中的作用 进程。要使用的方法包括ATPase活性测量， 荧光探针的动力学和平衡滴定 蛋白质成分。原肌球蛋白异构体的分离自平滑肌和 将使用突变的原肌球蛋白。使用从以下地址获得的信息 这些研究将是平滑肌调节的基本机制 更好地理解，几个平滑肌异常可以 特色化的。

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.