标题： 研究细菌细胞色素导线OmcS中的电子电导率区域 显示英文标题

标题： Investigating electron conductivity regimes in the bacterial cytochrome wire OmcS

摘要： 厌氧细菌\textit{硫还原地杆菌}产生细胞外、电子导电的细胞色素聚合物丝，这些丝在微米长度尺度上具有导电性。 来自冷冻电子显微镜数据的结构模型显示，OmcS 丝沿着蛋白质丝轴形成一个血红素的线性链，这被认为是支持其电子特性的结构基础。 OmcS 丝中血红素的几何排列在许多多血红素 c 型细胞色素和其他最近发现的微生物细胞色素丝中是保守的。 然而，这种血红素分子排列如何支持电子通过蛋白质和超分子血红素丝传输的机制尚不清楚。 在此，我们研究了 OmcS 中的位点能量、血红素间耦合以及长程电子导电性。 我们提出了一种方法，直接从 Kohn-Sham 密度泛函理论提取电荷载流子位点信息，而无需使用投影方案。 我们表明，位点和耦合能量对血红素几何结构和周围静电环境的变化非常敏感，这与直觉预期一致。 这些参数作为包含退相干修正的量子电荷载流子模型的输入，我们据此预测了一个与其他有机基电子材料相当的扩散系数。 基于这些模拟，我们提出动态无序，特别是由于扰动的血红素振动，使载流子能够克服静态无序引起的陷阱以及\textit{通过}的小频率依赖性波动。 这些研究提供了关于微生物细胞色素丝中长程电子导电性的分子和电子决定因素的见解，并突出了仿生、血红素基导电材料的设计原则。 显示英文摘要

摘要： The anaerobic bacterium \textit{Geobacter sulfurreducens} produces extracellular, electronically conductive cytochrome polymer wires that are conductive over micron length scales. Structure models from cryo-electron microscopy data show OmcS wires form a linear chain of hemes along the protein wire axis, which is proposed as the structural basis supporting their electronic properties. The geometric arrangement of heme along OmcS wires is conserved in many multiheme c-type cytochromes and other recently discovered microbial cytochrome wires. However, the mechanism by which this arrangement of heme molecules support electron transport through proteins and supramolecular heme wires is unclear. Here, we investigate the site energies, inter-heme coupling, and long-range electronic conductivity within OmcS. We introduce an approach to extract charge carrier site information directly from Kohn-Sham density functional theory, without employing projector schemes. We show that site and coupling energies are highly sensitive to changes in inter-heme geometry and the surrounding electrostatic environment, as intuitively expected. These parameters serve as inputs for a quantum charge carrier model that includes decoherence corrections with which we predict a diffusion coefficient comparable with other organic-based electronic materials. Based on these simulations, we propose that dynamic disorder, particularly due to perturbative inter-heme vibrations allow the carrier to overcome trapping due to the presence of static disorder \textit{via} small frequency-dependent fluctuations. These studies provide insights into molecular and electronic determinants of long-range electronic conductivity in microbial cytochrome wires and highlight design principles for bioinspired, heme-based conductive materials.