STRUCTURE FUNCTION STUDIES OF MUSCLE AND HEART

肌肉和心脏的结构功能研究

• 批准号: 3156643
• 负责人: JAGDISH GULATI
• 金额: $ 22.35万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-18 至 1996-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3156643
• 关键词: calcium binding protein; cardiotonic agents; chemical chain length; computer simulation; genetic manipulation; hamsters; heart contraction; heart failure; heart pharmacology; laboratory rabbit; molecular biology; muscle tension; myocardium disorder; protein structure function; sarcomeres; striated muscles; troponin; western blottings

The broad aim of this research is to establish the molecular basis of skeletal and cardiac muscle assembly and function in the normal tissue and in heart failure. The major present goals are (1) to use molecular genetics to study the length dependency of cardiac muscle (Starling's law of the heart) by defining the amino acid residues responsible for the length sensing mechanism. Specific manipulations of the structure of TnC will be correlated with alterations in the cardiac and skeletal length-tension curves. (2) We propose to investigate the basis of cooperativity in the Ca2+-switching processes of the thin filaments in cardiac muscle. Also, by examining the interactions of force modifying compounds, such as TFP as well as cardiotonic agents, with the Ca-binding proteins and their genetic variants, we will examine whether the hydrophobic residues of TnC participate in setting the cooperativity level in the Ca-force relations in muscle. In addition we will study the specific role of the central helix in TnC and calmodulin in the switching mechanisms. In particular, we propose to determine whether the central linker between the N- and C-terminal lobes is essential to function. Further, by combining the mutation studies with computer simulations, we will examine whether the bending of the central helix that could cause compaction of the molecule, is essential for the molecular dynamics related to ligand binding, and also whether the highly conserved arginine residues are implicated in this function. (3) We also propose to characterize the properties of cofactor-B. Cofactor-B, discovered in this lab, is a protein essential for reconstitution of extracted fibers. Our goals are to purify, clone, mutate, determine isoformic diversity, and study the expression of cofactor-B in normal tissue as well as during the development of cardiomyopathy of the Syrian hamster. A major hypothesis is suggested that cofactor-B controls the link between the weak and strong cross-bridge states.

本研究的主要目标是建立以下分子基础： 正常组织中的骨骼肌和心肌的组装和功能 和心力衰竭。 目前的主要目标是（1）利用分子 遗传学研究心肌的长度依赖性（斯塔林定律 心脏）通过定义负责的氨基酸残基 长度传感机制。 TnC 结构的具体操作 与心脏和骨骼的变化有关 长度-张力曲线。 (2) 我们建议调查的依据 细丝 Ca2+ 转换过程中的协同作用 心肌。 此外，通过检查力修改的相互作用 化合物，如 TFP 以及强心剂，与 Ca 结合 蛋白质及其遗传变异体，我们将检查是否 TnC 的疏水残基参与设定协同性 肌肉中钙力关系的水平。 此外，我们还将研究 TnC 和钙调蛋白中央螺旋在转换中的特殊作用 机制。 我们特别建议确定中央是否 N 端叶和 C 端叶之间的连接子对于功能至关重要。 此外，通过将突变研究与计算机模拟相结合，我们 将检查中央螺旋的弯曲是否会导致 分子的压缩对于分子动力学至关重要 与配体结合有关，以及是否高度保守的精氨酸 该功能涉及残基。 (3) 我们还建议 表征辅因子-B 的特性。 辅因子-B，发现于 该实验室是提取纤维重建所必需的蛋白质。 我们的目标是纯化、克隆、突变、确定同种型多样性， 并研究辅因子-B 在正常组织中以及在 叙利亚仓鼠心肌病的发展。 一个专业 假设辅因子 B 控制着 弱和强跨桥状态。