论文标题
生物自由能转导是平均场传输理论的致命弱点
Biological free energy transduction is an Achilles heel of mean-field transport theory
论文作者
论文摘要
纳米级生物运输的研究通常使用平均场近似值，仅当系统处于平衡状态并且网络中不同位点上粒子之间没有相互作用时，该研究仅是确切的。我们探讨了这种近似值的局限性，以描述酶功能和生物传输网络的各种粒子运输。我们的重点是三个生物能网络：线性电子转移链（如细菌纳米线中发现），一个氧化还原耦合的质子泵（如呼吸的复杂IV中），以及一个接近可逆的电子分支网络（如呼吸III和其他最近发现的结构和其他发现的结构）。远离平衡和典型的位点相互作用，我们发现平均场近似值充分描述了线性传输链。然而，平均场近似失败了灾难性地描述能量转换系统，例如在氧化还原耦合质子泵和可逆的电子分叉反应中。平均场近似未能捕获防止滑倒事件并产生有效的能量转导所需的基本相关性。
Studies of nanoscale biological transport often use a mean-field approximation that is exact only when the system is at equilibrium and there are no interactions between particles on different sites in the network. We explore the limitations of this approximation to describe many-particle transport in the context of enzyme function and biological transport networks. Our focus is on three bioenergetic networks: a linear electron transfer chain (as found in bacterial nanowires), a redox-coupled proton pump (as in complex IV of respiration), and a near reversible electron bifurcation network (as in complex III of respiration and other recently discovered structures). Away from equilibrium and with typical site-site interactions, we find that the mean-field approximation adequately describes linear transport chains. However, the mean-field approximation fails catastrophically to describe energy-transducing systems, as in the redox coupled proton pump and reversible electron bifurcation reactions. The mean-field approximation fails to capture the essential correlations that are needed to prevent slippage events and to produce efficient energy transduction.
