CAREER: Rational design of non-heme iron halogenases

氟、氯、溴和碘是高活性元素，称为卤素。将卤素连接到其他分子（卤化）是一个重要的化学反应。然而，将卤素化学连接到特定原子上是困难的，不精确的，并且通常表现出低产率。在化学，生物工程，环境和运输系统（CBET）部门的细胞和生物化学工程（CBE）计划以及化学部门（CHE）的生命过程化学（CLP）计划的支持下，该项目代表了使用旨在将卤素添加到分子中的酶来克服这些问题的尝试。一种能够以高度特异性将氯和溴天然地添加到分子中的酶将被重新设计为也添加氟。将通过辅导和指导加强参与该项目的学生和博士后的科学沟通技能。少数民族学生的参与将旨在激发他们的科学好奇心。SyrB 2是一种非血红素铁卤化酶，使用环境友好的氧气、α-酮戊二酸和氯化物/溴化物作为起始材料，催化氨基酸苏氨酸的化学选择性和区域选择性氯化/溴化。通过合理调节酶的一级配位圈和二级配位圈以及蛋白质间的相互作用，可以拓宽酶的反应范围和底物混杂性。目标1集中于开发配体活化剂，其将反应范围扩大到包括双氢吡喃。目标2设计了一种卤代羟铁中间体的氢键相互作用，使其底物与其他氨基酸的混杂性扩大。目的3设计诱饵肽，消除SyrB 2对其蛋白伴侣的依赖性，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、功能和机制知识，并为可持续合成化学过程中铁依赖酶的合理和计算设计建立框架。该奖项反映了NSF的法定使命，并通过使用基金会的智力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.