Thermodynamics and Kinetics of a Binary Mechanical System: Mechanisms of Muscle Contraction.
Thermodynamics and Kinetics of a Binary Mechanical System: Mechanisms of Muscle Contraction.
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DOI：
10.1021/acs.langmuir.2c01622
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发表时间：
2022-12-27
期刊：
影响因子：
3.9
通讯作者：
Baker, Josh E.
中科院分区：
文献类型：
--
作者：
Baker, Josh E.
生物马达在生物学、物理学和化学的界面上发挥作用，并且仍然没有确定哪些学科的规则解释了这些马达如何工作。肌球蛋白马达是通过涉及由肌动蛋白结合诱导的开关样肌球蛋白结构变化（杠杆臂旋转）的机制催化ATP水解的酶，所述肌动蛋白结合产生肌动蛋白丝的小位移。在肌肉中，个体肌球蛋白马达被广泛认为是具有类似于肌肉的机械特性的分子机器。从这个角度出发，在这里，我表明，肌肉更接近类似于一个热发动机的机械性能，出现从热力学的肌球蛋白电机合奏。热力学对我们理解热机如何工作的变革性影响，引导了我们理解肌肉如何工作的平行变革。我认为最简单的可能模型的力量产生：一个二元力学系统。我开发的力学，能量学和动力学的这个系统，并表明，一个单一的绑定反应产生的力量时，肌肉被保持在一个固定的长度和执行工作时，肌肉被允许缩短。这产生了热力学结合途径的网络，其类似于肌肉的许多特征性机械和能量行为，包括肌肉力-速度关系、缩短肌肉的热输出、肌肉张力瞬变的四个阶段、自发振荡收缩和力再发展。类似于热力发动机的热力学（卡诺）循环，等温和绝热结合和分离反应为肌肉产生类似于心脏压力-容积环的热力学循环（即，心脏是如何工作的）。本文概述了如何使用热力学重新解释肌肉力学数据-这是一项持续的努力，将继续为肌肉和分子马达如何工作提供新的见解。
Biological motors function at the interface of biology, physics, and chemistry, and it remains unsettled what rules from which disciplines account for how these motors work. Myosin motors are enzymes that catalyze the hydrolysis of ATP through a mechanism involving a switch-like myosin structural change (a lever arm rotation) induced by actin binding that generates a small displacement of an actin filament. In muscle, individual myosin motors are widely assumed to function as molecular machines having mechanical properties that resemble those of muscle. In a fundamental departure from this perspective, here, I show that muscle more closely resembles a heat engine with mechanical properties that emerge from the thermodynamics of a myosin motor ensemble. The transformative impact of thermodynamics on our understanding of how a heat engine works guides a parallel transformation in our understanding of how muscle works. I consider the simplest possible model of force generation: a binary mechanical system. I develop the mechanics, energetics, and kinetics of this system and show that a single binding reaction generates force when muscle is held at a fixed length and performs work when muscle is allowed to shorten. This creates a network of thermodynamic binding pathways that resembles many of the characteristic mechanical and energetic behaviors of muscle including the muscle force–velocity relationship, heat output by shortening muscle, four phases of a muscle tension transient, spontaneous oscillatory contractions, and force redevelopment. Analogous to the thermodynamic (Carnot) cycle for a heat engine, isothermal and adiabatic binding and detachment reactions create a thermodynamic cycle for muscle that resembles cardiac pressure–volume loops (i.e., how the heart works). This paper provides an outline for how to re-interpret muscle mechanic data using thermodynamics – an ongoing effort that will continue providing novel insights into how muscle and molecular motors work.
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影响因子：
3.4
作者：
Baker, Josh E.
通讯作者：
Baker, Josh E.
影响因子：
3.4
作者：
Baker, JE;Brosseau, C;Warshaw, DM
通讯作者：
Warshaw, DM
影响因子：
64.8
作者：
FINER, JT;SIMMONS, RM;SPUDICH, JA
通讯作者：
SPUDICH, JA
DOI：
10.1073/pnas.95.6.2944
发表时间：
1998-03-17
影响因子：
11.1
作者：
Baker, JE;Brust-Mascher, I;Thomas, DD
通讯作者：
Thomas, DD
DOI：
10.1098/rspb.1938.0050
发表时间：
1938-10-01
期刊：
PROCEEDINGS OF THE ROYAL SOCIETY SERIES B-BIOLOGICAL SCIENCES
影响因子：
--
作者：
Hill, AV
通讯作者：
Hill, AV