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)以及相关的生物工程和物理科学方法正被应用于研究与生理学和病理学有关的肌肉生物物理学。我们研究了肌肉和脑中钙离子敏感蛋白钙调蛋白和具有乙醛辅酶A脱氢酶、乙醇脱氢酶和丙酮酸甲酸裂解酶(PFL)失活功能的多亚单位酶ADE的结构和力响应特性。我们使用了先进的AFM成像和测力技术，并仔细研究了相关的固定底物的效果。更广泛地说，我们正在研究大型肌肉蛋白的弹性行为，如肌蛋白(一种由3-4个丙二醛组成的巨型多肽链)和星云蛋白(600-900 kDa)。我们发表了一篇关于利用原子力显微镜、激光光阱(LOT)和相关的单分子技术来研究Titin的综合综述，以及由此产生的对Titin生物物理性质的理解。系统的AFM测量和广泛的数据解释工作正专注于了解Titin分子的PEVK基序的弹性，该基序具有维持骨骼肌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取得进展。

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.