Chirality-Induced Spin Selectivity in Biology:The Role of Spin-Polarized Electron Current in Biological Electron Transport & Redox Enzymatic Activity

电荷传递是生物系统中的一个基本过程，它是细胞活动和代谢的基础。参与这个项目的研究旨在扩大我们对电子作为电荷载体的理解，它是如何在导体非常差的生物材料中远距离传输的，而不是家庭或工业电线。它还专注于一种特定的酶过程，在这种过程中，酶加速了生物分子被氧化或还原的过程中涉及的化学反应，即失去或获得电子，这是细胞功能的基本步骤。在这项计划中，电子在生物分子中的传输是通过一种基于先进的多肽合成和蛋白质工程的协同理论-实验工作以及单分子水平上的电流测量来研究的。这项研究与我们对生物和细胞功能的理解有关。此外，它还促进了我们对生物系统中普遍存在的右手和左手分子中电子传输的基本方面的了解。这项研究在传感和分子量子信息领域也具有重要意义。博士后研究员将通过与国际合作者的互动接受交叉培训。该项目将通过提供传感器和诊断平台的基本知识，在学术界和工业界之间建立联系。这个项目将研究手性多肽基质中产生的电子自旋极化在生物学中两个非常有效的氧化还原过程中的作用：(1)长程电子传递和(2)氧化还原酶反应，两者都由氧化还原辅因子介导。这两个目标将通过首先研究通过定制螺旋肽的电流的自旋极化机制来实现，这些螺旋肽构成了围绕氧化还原辅因子的手性基质的主要构建块。其次，评估上述螺旋诱导的自旋极化对氧化还原细胞色素模型电子传输效率的影响。第三，评价其对氧化还原反应速度的影响。这项研究将在单肽/蛋白质水平上进行，使用一种独特的方法，将先进的单分子电导表征与多肽合成和蛋白质工程相结合。单肽/蛋白质法测量分子电导是在电化学扫描隧道显微镜的精确控制的纳米级电极-电极间隙中进行的，它允许在生理条件下操作。这种生物物理方法集成了整个单分子装置的电子电导的原子计算模型，包括分子和接触。这一美英合作项目得到了美国国家科学基金会和英国生物技术和生物科学研究理事会的支持，其中NSF资助美国的研究人员，BBSRC资助英国的合作伙伴。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Charge transport is a fundamental process in biological systems, it underlies cell activity and metabolism. The research involved in this project aims to expand our understanding about how electrons, the charge carriers, travel long distances in biological materials that are very poor conductors, as opposed to home or industrial electrical wires. It also focuses on a specific kind of enzymatic process where enzymes accelerate the chemical reactions involved in processes where biomolecules are oxidized or reduced, that is lose or gain electrons, a fundamental step in cell functionality. In this project, electron transport in biomolecules is studied through a synergistic theory-experimental effort which relies on advanced peptide synthesis and protein engineering and the measurement of currents at the single-molecule level. This research is relevant for our understanding of biological and cell function. Also, it advances our knowledge regarding fundamental aspects of electron transport in right-handed and left-handed molecules, which are pervasive in biological system. The investigation can also be of importance in the areas of sensing and molecular quantum information. A postdoctoral fellow will be receive cross-training by interactions with international collaborators. This project will create a link between academia and industry by delivering fundamental knowledge for sensor and diagnostic platforms. This project will study the role the electron spin-polarization generated in a chiral peptide matrix has on two remarkably efficient redox-based processes in biology; (1) the long-range electron transport and (2) the redox enzymatic reactions, both mediated by redox cofactors. These two aims will be achieved by first investigating the spin-polarization mechanisms of the electric current flowing through bespoke helical peptides, which constitute the main building blocks of the chiral matrix surrounding redox cofactors. Second, evaluating the impact of the above helix-induced spin-polarization in the electron transport efficiency of a model redox cytochrome. And third, evaluating its impact in the reaction rate of a redox enzymatic processes. The study will be carried out at the single peptide/protein level of resolution using a unique approach that combines advanced single-molecule conductance characterization with peptide synthesis and protein engineering. The single-peptide/protein method to measure molecular conductance is carried out in a precisely controlled nanoscale electrode-electrode gap of an electrochemical scanning tunnelling microscope, which allows operation in physiological conditions. This biophysical approach integrates an atomistic computational modelling of electron conductance of the entire single-molecule device, including both the molecules and the contacts. This collaborative US/UK project is supported by the US National Science Foundation and the UK Biotechnology and Biological Sciences Research Council where NSF funds the US investigator and BBSRC funds the UK partner.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.