Molecular mechanics of mutant cardiac myosin

突变型心肌肌球蛋白的分子力学

基本信息

批准号：
7393140
负责人：
JEFFREY R MOORE
金额：
$ 32.5万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-04-01 至 2009-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7393140
关键词：
ATP phosphohydrolase Accounting Actins Actomyosin Address Affect Affinity American Attenuated Behavior Binding Binding Sites Biological Assay Cardiac Cardiac Myosins Complex Contractile Proteins Defect Dependence Development Diffusion Disease EF Hand Motifs Elasticity Familial Hypertrophic Cardiomyopathy Fiber Fibrosis Filament Generations Goals Head Heart Heart Hypertrophy Heart failure Human Hypertrophy In Vitro Isometric Exercise Kinetics Knowledge Lasers Lead Length Light Localized Measurement Measures Mechanics Methods Microfilaments Molecular Monitor Motion Movement Muscle Cells Muscle Contraction Muscle Fibers Mutation Myocardium Myosin ATPase Myosin Heavy Chains Myosin Regulatory Light Chains Neck Nucleic Acid Regulatory Sequences Output Patients Performance Phenotype Phosphorylation Phosphorylation Site Preparation Process Production Property Proteins Protocols documentation Range Rate Reporting Research Personnel Serine Skin Sudden Death System Techniques Testing Therapeutic Thick Filament Thin Filament Thinking Time Transgenic Mice Ventricular Myosins Vertebral column Work base cell motility disease phenotype in vivo innovative technologies molecular mechanics mutant novel optical traps programs research study single molecule sudden cardiac death

项目摘要

DESCRIPTION (provided by applicant): Familial hypertrophic cardiomyopathy (FHC) is a disease characterized by cardiac hypertrophy, myofibrillar disarray and sudden death. FHC results from autosomal dominant mutations in sarcomeric proteins. The goal of this proposal is to provide a molecular basis for FHC in patients with mutations in the myosin regulatory light chain (RLC). These studies are a necessary precursor to development of therapeutic protocols that will attenuate the effects of heart failure. The mutations are localized near the phosphorylatable serine, the EF hand, and the MHC binding regions of the RLC molecule and, since the RLC binding region of myosin is thought to undergo large conformational changes that drive muscle contraction, we will address fundamental aspects of RLC function and the molecular basis of myosin motion generation. Our approach will utilize laser-trapbased in vitro force and motility assays to assess the effects of RLC mutations on: 1) unloaded shortening velocity, 2) isometric force, 3) Ca++ sensitivity and 4) power production from mutant myosin ensembles. Any alterations in ensemble behavior will be further pursued at the single myosin molecule level to determine if they result from altered mechanical properties or from changes in the rates ofactomyosin kinetic transitions. Our approach measures the mechanical properties of isolated contractile proteins. Since the method is free from the ambiguities arising from mechanical experiments using skinned fiber and whole heart preparations (e. g.: myocyte disarray, fibrosis, and diffusion limitations), it is the purest way to determine the direct effects of the FHC mutations on actomyosin force and power generation. Knowledge of how the RLC mutations affect myosin's inherent function will allow the degree of alteration to higher functional units, such as the cardiac muscle fiber, or the heart itself to be correlated with a primary contractile defect.