Muscle Protein Biophysics Via Atomic Force Microscopy

在与NIAMS研究人员的持续合作中，原子力显微镜（AFM）和相关的生物工程和物理科学方法正在应用于研究与生理和病理相关的肌肉生物物理学。我们研究了钙调素（一种肌肉和大脑中的Ca2+感应蛋白）和AdhE（一种多亚基酶，具有乙醛-辅酶a脱氢酶、醇脱氢酶和丙酮酸甲酸裂解酶（PFL）失活酶的功能）的结构和力响应特性。我们使用先进的AFM成像和力测量技术，仔细研究了相关固定基质的效果。更广泛地说，我们正在研究大型肌肉蛋白的弹性行为，如titin （3-4 MDa的大量肽链）和nebulin （600-900kDa）。本文综述了利用原子力显微镜（AFM）、激光光阱（LOT）和相关单分子技术对titin生物物理性质的研究进展。系统的AFM测量和大量的数据解释工作都集中在了解titin分子PEVK基元的弹性上，它具有维持骨骼和心肌组织和力反应的关键功能。对星云蛋白的平行研究也在进行中。

In a continuing collaboration with NIAMS researchers, atomic force microscopy (AFM) and related bioengineering and physical science methods are being applied to investigate muscle biophysics in relation to physiology and pathologies. We studied the structure and force response properties of Calmodulin, a Ca2+-sensing protein in muscle and brain, and AdhE, a multi-subunit enzyme with functions: acetaldehyde-CoA dehydrogenase, alcohol dehydrogenase, and pyruvate formate lyase (PFL) deactivase. We used advanced AFM imaging and force measurement techniques and carefully studied the effect of the associated immobilization substrate. More extensively, we are working on elastic behaviour of the large muscle proteins such as titin (a massive peptide chain of 3-4 MDa) and nebulin (600-900kDa). We published a comprehensive review of titin research employing AFM, laser optical trap (LOT), and related single molecule technologies, and the resulting understanding on titin biophysical properties. Systematic AFM measurements with extensive data interpretation effort are being focused on understanding the elasticity of the PEVK motif of titin molecule, which has crucial functions of maintaining skeletal and cardiac muscle organization and force responses. Parallel investigations on the nebulin protein are also progressing.