Department of Applied Physics, School of Science, Xi'an University of Technology, Xi'an, Shaan Xi 710048, China.
Department of Physics and NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117542, Singapore.
Biochim Biophys Acta Bioenerg. 2021 Apr 1;1862(4):148369. doi: 10.1016/j.bbabio.2021.148369. Epub 2021 Jan 14.
FF ATP synthase is a ~100% efficient molecular machine for energy conversion in biology, and holds great lessons for man-made energy technology and nanotechnology. In light of formidable biocomplexity of the FF machinery, its modeling from pure physical principles remains difficult and rare. Here we construct a thermodynamic model of FF from experimentally accessible quantities plus a single entropy production that generally has vanishingly small values (<1k). Based on the physical inputs, this model captures FF performance observed over an exhaustively wide range of proton-motive force and nucleotide concentrations. The model predicts a distinct 1/8kT slope for ATP synthesis rate versus proton-motive force, which is verified by experimental data and represents a profound thermodynamic marking of this amazingly efficient machine operating near a universal limit of the 2nd law of thermodynamics. The model further predicts two symmetries of heat productions, which are testable by available experimental techniques and offer quantitative constraints on FF's possible mechanisms behind its ~100% efficiency.
FF ATP 合酶是生物学中能量转换的一种100%高效的分子机器，为人工能源技术和纳米技术提供了重要的启示。鉴于 FF 机械装置复杂的生物特性，从纯物理原理对其进行建模仍然具有一定难度，且较为少见。在此，我们基于可从实验中获取的数量以及一个通常具有极小值（<1k）的单一熵产生量，构建了一个 FF 的热力学模型。基于物理输入，该模型可捕捉到在极其广泛的质子动力势和核苷酸浓度范围内观察到的 FF 性能。该模型预测了 ATP 合成速率与质子动力势之间具有独特的 1/8kT 斜率，这一预测得到了实验数据的验证，并且代表了这种令人惊叹的高效机器在接近热力学第二定律的普遍极限下运行的深刻的热力学标志。该模型进一步预测了热产生的两个对称性，这些对称性可以通过现有的实验技术进行检验，并为 FF 达到100%效率的可能机制提供了定量约束。
