Modulation of Metalloprotein Activities through Fine-tuning Reduction Potentials

在化学部生命过程化学(CLP)项目的支持下，伊利诺伊大学香槟分校的Yi Lu博士计划通过微调还原电位来调节金属蛋白的活性。在这一过程中，这项研究将有助于从根本上理解如何调整还原电位并将其与功能性质相关联。许多化学和生物过程涉及氧化还原反应，其效率在很大程度上由还原电位决定。在自然界中，每一种金属蛋白都覆盖了其功能所需的一定还原潜力范围。对影响不同金属蛋白在整个生理还原潜力范围内还原潜力的共同因素的系统理解仍然难以捉摸。为了解决这一限制，Lu团队计划改造天青蛋白来改变铜位置的还原电位，以解决调节还原电位如何调节酶功能的问题，这一知识将适用于许多生物和化学系统。陆博士将通过为本科生和研究生课程开发包含多学科研究成果的讲座和实验模块，将研究与教育相结合。国际和平研究所将通过外展活动，从STEM(科学、技术、工程和数学)中任职人数较少的群体中招募学生参与研究，并创建和维护一种多样化、公平和包容性的文化，使应征人员在学习和研究中茁壮成长。该项目建立在Lu博士的实验室之前的成功基础上，该实验室成功地调整了天青素中第一类铜中心的还原潜力，以最大限度地减少对主配位球的扰动，使其跨越2V生理E：范围。它着重于工程二次配位球相互作用，包括氢键(H键)和疏水性来调节金属蛋白的活性，包括(1)工程天青中铜中心的S-亚硝化反应和非血红素铁中心的逐步亚硝化，(2)小漆酶中T1铜中心的氧还原活性，以及(3)改变天青中Fe-S簇合物的还原电位。对这些目标的追求有望导致对如何调整金属蛋白的还原潜力以及如何将金属蛋白的功能扩展到电子转移之外的更深层次的见解。这一新知识可以作为设计具有可预测还原潜力的金属蛋白质和金属络合物的坚实基础，这些金属蛋白和金属络合物可用于太阳能转换、燃料电池和小分子激活等应用。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。

With the support of the Chemistry of Life Processes (CLP) Program in the Chemistry Division, Dr. Yi Lu from the University of Illinois at Urbana-Champaign plans to modulate metalloprotein activities through fine-tuning reduction potentials. In the process, the research will contribute to the fundamental understanding of how to tune reduction potentials and correlate it with functional properties. Many chemical and biological processes involve redox reactions, whose efficiency is largely defined by reduction potentials. In Nature, each metalloprotein covers a certain reduction potential range required for its function. A systematic understanding of common factors that affect the reduction potential of different metalloproteins across the entire range of physiological reduction potentials remains elusive. To address this limitation, the Lu group plans to engineer the protein azurin to vary the reduction potential of the copper site to address the question of how tuning reduction potentials can modulate enzymatic functions, knowledge that would be applicable to many biological and chemical systems. Dr. Lu will integrate research with education through developing lecture and lab modules for undergraduate and graduate courses that incorporate multidisciplinary research results. The PI will focus on recruiting students from groups underrepresented in STEM (science, technology, engineering and mathematics) to participate in the research through outreach activities and on creating and maintaining a diverse, equitable, and inclusive culture to allow the recruits to thrive in learning and research. This project builds on the previous success in Dr. Lu’s lab in tuning the reduction potential of the type 1 copper center in azurin to span a 2 V physiological Eº´ range with minimal perturbation of the primary coordination sphere. It focuses on the engineering secondary coordination sphere interactions, including hydrogen bonding (H-bonding) and hydrophobicity to modulate metalloprotein activities, including (1) the S-nitrosylation reactivity of a Cu site and stepwise nitrosylation of a nonheme Fe site in an engineered azurin, (2) the oxygen reduction activity of the T1Cu center in a small laccase, and (3) changing the reduction potential of an Fe-S cluster incorporated into azurin. The pursuit of these objectives is expected to result in deeper insights into how reduction potentials of metalloproteins can be tuned and how the functions of metalloproteins can be expanded beyond electron transfer. The new knowledge could serve as a strong basis for the design of metalloproteins and metal complexes with predictable reduction potentials that can be used in applications such as solar energy conversion, fuel cells, and small molecule activation.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.