CAREER: Rational design of non-heme iron halogenases

氟、氯、溴和碘是高活性元素，称为卤素。卤素与其他分子的结合（卤化）是一种重要的化学反应。然而，用化学方法将卤素连接到一个特定的原子上是困难的、不精确的，而且产率往往很低。在化学、生物工程、环境和运输系统学部（CBET）的细胞与生物化学工程（CBE）项目和化学学部（CHE）的生命过程化学（CLP）项目的支持下，该项目代表了利用酶向分子中添加卤素来克服这些问题的尝试。一种酶可以自然地将氯和溴添加到具有高特异性的分子中，这种酶将被重新设计以添加氟。通过辅导和指导，加强参与项目的学生和博士后的科学沟通能力。少数族裔学生的参与旨在激发他们对科学的好奇心。syb2是一种非血红素铁卤化酶，以环境友好的氧、α -酮戊二酸和氯/溴为起始原料，催化氨基酸苏氨酸的化学和区域选择性氯化/溴化。通过合理调节酶的一级配位和二级配位以及蛋白-蛋白相互作用，可以扩大酶的反应范围和底物混杂性。目标1的重点是开发配体激活剂，扩大反应范围，包括氟化。目的2设计与卤羟基铁中间体的氢键相互作用，将其底物混杂性扩展到其他氨基酸。目的3设计诱饵肽，消除syb2对其蛋白伙伴的依赖性，以传递底物并触发催化。该项目将推进非血红素铁酶的结构、功能和机理知识，并为可持续合成化学过程中铁依赖性酶的合理和计算设计建立框架。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。

Fluorine, chlorine, bromine, and iodine are highly reactive elements called halogens. Attaching halogens to other molecules (halogenation) is an important chemical reaction. However, attaching halogens to a specific atom chemically is difficult, imprecise, and often exhibits low yields. With the support from the Cellular and Biochemistry Engineering (CBE) Program in the Division of Chemical, Bioengineering, Environmental and Transport Systems (CBET) and the Chemistry of Life Processes (CLP) Program in the Division of Chemistry (CHE), this project represents an attempt to overcome these problems using enzymes designed to add halogens to molecules. An enzyme that naturally adds chlorine and bromine to molecules with high specificity will be redesigned to add fluorine as well. The scientific communication skills of students and post docs engaged in the project will be strengthened through coaching and instruction. The participation of underrepresented minority students will be designed to stimulate their scientific curiosity.SyrB2 is a non-heme iron halogenase that catalyzes chemo- and regio-selective chlorination/bromination of amino acid threonine using environmentally-friendly oxygen, alpha-ketoglutarate, and chloride/bromide as starting materials. Its reaction scope and substrate promiscuity will be broadened by rationally modulating the enzyme’s primary and secondary coordination sphere as well as protein-protein interactions. Objective 1 focuses on developing ligand activators that expand the reaction scope to include fluorination. Objective 2 designs hydrogen-bond interactions to a halohydroxoferric intermediate that expands its substrate promiscuity to other amino acids. Objective 3 engineers decoy peptides that eliminate the dependency of SyrB2 on its protein partner for delivering the substrate and triggering catalysis. The project will advance structural, functional, and mechanistic knowledge of non-heme iron enzymes and establish the framework for the rational and computational design of iron-dependent enzymes for sustainable synthetic chemical processes.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.