Unraveling the dynamics that enable unusual heme enzyme reactivity

摘要 酶是至关重要的生物催化剂，可以加速所有领域的挑战性反应 生命虽然结构生物学方法在过去世纪的发展使得 这些迷人的系统的可视化，我们对动态过程的理解， 由于它们发生的时间尺度，促进酶反应性仍然是有限的。的 我的研究小组的首要目标是开发和应用时间分辨方法， 可视化这些过程，以阐明含金属酶的机制， 对人类健康和医学的贡献。血红素依赖性酶由于它们的特性而受到特别关注。 在有氧代谢中的作用，包括信号传导、抗生素生物合成和免疫 反应尽管具有相似的结构基序和催化中间体， 酶能够催化超出其原型的广泛反应。 羟基化结果。本项目旨在研究其结构特征和动力学 这种非典型的反应行为，使从二氧化硝化和超越。在 特别是，我们计划重新利用能够暂停营业额的生化工具，如 底物/辅因子类似物和定点诱变，以及应用最先进技术， 我的团队目前正在开发的解决方法， 通过X射线晶体学和光谱学方法的组合来制备中间体。 尽管应用于本文中的特定系统，但所提出的方法可在本文中具有实用性。 更广泛地研究血红素酶，以及其他金属酶。同样， 结果有可能影响生物催化和下游发展， 癌症和传染病治疗的生物技术和疗法。

ABSTRACT Enzymes are crucial biological catalysts that expedite challenging reactions across all domains of life. While the development of structural biology methods over the past century has enabled visualization of these fascinating systems, our understanding of the dynamic processes that facilitate enzyme reactivity remains limited due to the timescales on which they occur. The overarching goal in my research group is to develop and apply time-resolved methods capable of visualizing these processes to elucidate the mechanisms of metal-containing enzymes important for human health and medicine. Heme-dependent enzymes are of particular interest due to their role in aerobic metabolism ranging from signal transduction, antibiotic biosynthesis and immune response. Despite sharing similar structural motifs and catalytic intermediates, heme-dependent enzymes are capable of catalyzing a wide range of reactions beyond their archetypal hydroxylation outcomes. This project aims to investigate the structural features and dynamic behavior that enables this atypical reactivity from dioxygenation to nitration and beyond. In particular, we plan to repurpose biochemical tools capable of pausing turnover, such as substrate/cofactor analogs and site-directed mutagenesis, as well as apply state-of-the-art time- resolved methods that my group is currently developing, to visualize short-lived catalytic intermediates via a combination of X-ray crystallographic and spectroscopic approaches. Although applied to specific systems herein, the proposed methodologies may have utility in the study of heme-enzymes more broadly, as well as other metalloenzymes. Likewise, the anticipated results have the potential to impact both biocatalysis and the downstream development of biotechnologies and therapeutics in the treatment of cancers and infectious diseases.