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的一个基本过程，它是细胞活动和代谢的基础。这个项目涉及的研究旨在扩大我们对电子（电荷载体）如何在生物材料中长距离传播的理解，而生物材料是非常差的导体，而不是家用或工业电线。它还关注一种特殊的酶促过程，其中酶加速生物分子氧化或还原过程中的化学反应，即失去或获得电子，这是细胞功能的基本步骤。在这个项目中，电子在生物分子中的传递是通过协同理论和实验的努力来研究的，它依赖于先进的肽合成和蛋白质工程以及单分子水平上的电流测量。这项研究与我们对生物学和细胞功能的理解有关。此外，它还提高了我们对生物系统中普遍存在的左手和右手分子中电子传递的基本方面的认识。这项研究在传感和分子量子信息领域也具有重要意义。博士后将通过与国际合作伙伴的互动进行交叉培训。该项目将通过为传感器和诊断平台提供基础知识，在学术界和工业界之间建立联系。本项目将研究手性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)远程电子传递和(2)氧化还原酶反应，均由氧化还原辅助因子介导。这两个目标将通过首先研究流过定制螺旋肽的电流的自旋极化机制来实现，螺旋肽构成了围绕氧化还原辅助因子的手性基质的主要组成部分。其次，评估上述螺旋诱导的自旋极化对模型氧化还原细胞色素电子传递效率的影响。第三，评价其对氧化还原酶过程反应速率的影响。该研究将在单肽/蛋白质的分辨率水平上进行，使用一种独特的方法，将先进的单分子电导表征与肽合成和蛋白质工程相结合。单肽/蛋白测量分子电导的方法是在电化学扫描隧道显微镜精确控制的纳米级电极-电极间隙中进行的，可以在生理条件下操作。这种生物物理方法集成了整个单分子器件的电子电导的原子计算模型，包括分子和接触。这项英美合作项目由美国国家科学基金会和英国生物技术和生物科学研究委员会资助，其中美国国家科学基金会资助美国研究者，英国生物科学研究委员会资助英国合作伙伴。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.