Deeper Understanding of Factors that Fine-tune Redox Potentials of Metalloproteins

凭借这一奖项，化学学部生命过程化学项目资助伊利诺伊大学厄巴纳-香槟分校（UIUC）的Yi Lu博士研究微调含金属蛋白质（金属蛋白）能量的因素。许多化学和生物过程都涉及电子从一个分子转移到另一个分子的反应。众所周知，大自然利用金属蛋白来控制这些电子转移，使它们发生在特定的分子对中。本研究合成了生物金属蛋白的模拟物，用于非常特殊的电子转移。这些金属蛋白也用于太阳能转换和燃料电池的催化过程中。这些研究项目将研究生和本科生培养成下一代科学家。从多个领域获得的知识和技能为学生解决科学和社会面临的难题做好了准备。彝族包括来自不同人口结构的学生。通过开发讲座和实验室模块，将项目的多学科研究成果整合到研究生和本科生课程中，UIUC的校园基础设施得到加强。该项目旨在加强对微调金属蛋白氧化还原电位（Eº´）的因素的定量理解，并将所获得的知识应用于设计具有调节功能特性的系统。许多研究已经确定了哪些因素对调整Eº´很重要。关于这些特性如何定量地对Eºo调优做出贡献的信息要少得多。为了实现这一目标，在金属的一级和二级配位球中都设计了非天然氨基酸，以隔离一个因子（例如位阻）和另一个因子（例如电子）。在这种方法中，Eº`调优变得更加可预测和定量。此前，易教授的实验室证明，1型铜蓝蛋白的调谐足以跨越整个2伏的生理范围。为了进一步了解铜氧还毒素，利用环导向诱变将1型铜中心整合到ephrin-B2（一种不含氧化还原中心的蛋白质）中。通过突变的氧化还原调谐和二次配位效应控制了紫铜蓝蛋白催化的可逆硫-亚硝基化反应。评估项目是否成功的标准是：a)通过天然和非天然氨基酸掺入实现的Eº´范围；b)突变导致的Eº´的可预测性；c)可逆NO结合的控制程度。

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Yi Lu from the University of Illinois at Urbana-Champaign (UIUC) to investigate the factors that fine-tune the energies of metal-containing proteins (metalloproteins). Many chemical and biological processes involve reactions where electrons are transferred from one molecule to another. Nature is known to use metalloproteins to control these electron transfers so that they occur within specific pairs of molecules. This research synthesizes mimics of biological metalloproteins that have use in very specific electron transfers. These metalloproteins are also used in catalytic processes involved in solar energy conversion and fuel cells. The research projects educate graduate and undergraduate students as the next generation of scientists. The knowledge and skills acquired from multiple fields are preparing students to tackle difficult problems facing science and society. The Yi group includes students from diverse demographics. The UIUC campus infrastructure is enhanced by developing lecture and lab modules to integrate the multidisciplinary research results of the project into graduate and undergraduate courses.This project seeks an enhanced quantitative understanding of the factors that fine-tune metalloprotein redox potentials (Eº´) and applies the knowledge gained to design systems with modulated functional properties. Many studies have identified which factors are important for tuning the Eº´. Much less information is available on how these features quantitatively contribute to Eº´ tuning. To achieve this goal, unnatural amino acids are engineered in both primary and secondary coordination spheres of the metal to isolate one factor (e.g., steric) from another (e.g., electronic). In this approach, Eº´ tuning becomes more predictable and quantitative. Previously, Professor Yi's lab demonstrated that tuning of a type 1 copper azurin is sufficient to span the entire 2 volt physiological range. In order to advance knowledge beyond cupredoxins, loop-directed mutagenesis is used to incorporate a type 1 copper center into ephrin-B2, a protein that does not contain a redox center. Redox tuning and secondary coordination effects through mutations are used to control reversible Sulfur-nitrosylation catalyzed by a red copper azurin. The success of the project is assessed by a) the range of Eº´ achieved through natural and unnatural amino acid incorporation; b) the predictability of Eº´ resulting from mutations; and c) the degree of control achieved in reversible NO binding.