Methylation in Antibiotic Biosynthesis: Methylcobalamin-Radical SAM Enzymes

抗生素生物合成中的甲基化：甲钴胺-自由基 SAM 酶

基本信息

批准号：
7653870
负责人：
Danica Galonic Fujimori
金额：
$ 24.9万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-06-01 至 2011-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7653870
关键词：
Anabolism Antibiotics Binding Bioinformatics Carbohydrates Carbon Carrier Proteins Catalysis Cations Chemistry Cobalamin Commit Coumarins Damon Runyon Cancer Research Foundation Development Dissociation Environment Enzymatic Biochemistry Enzymes Event Generations Goals Hydrogen Illinois In Vitro Investigation Iron Joints Kinetics Laboratories Lead Leucine Ligation Logic Mediating Metals Methionine Methods Methylation Methyltransferase Monobactams Nature Organic Chemistry Peptides Positioning Attribute Postdoctoral Fellow Proline Pyrroles Reaction Research Scheme Side Sulfur System Techniques Thienamycins Universities Variant Yugoslavia abstracting alpha benzopyrone bacterial resistance barbamide carboxylate chlorination clorobiocin combinatorial coumermycins falls halogenation inhibitor/antagonist medical schools member methyl group novel overexpression pharmacophore prevent professor reconstitution success

项目摘要

I have obtained B. Sc. in chemistry from University of Belgrade, Serbia and Montenegro, in 2000, and Ph. D. in organic chemistry from University of Illinois at Urbana-Champaign in May 2005. During graduate studies, I have developed new methods for the chemoselective carbohydrate-peptide ligations under the joint guidance of Professors David Y. Gin and Wilfred A. van der Donk. Currently, I am a Damon Runyon Cancer Research Foundation postdoctoral fellow in the laboratory of Professor Christopher T. Walsh at Harvard Medical School. HMS and Professor Walsh are providing an outstanding research environment and are committed to the success of the postdoctoral fellows. My postdoctoral research is focused on the characterization of a recently discovered class of nonheme Fe (II) halogenases, capable of carrying out halogenation of unactivated carbon centers. Thus far, we have reconstituted halogenation activity in the barbamide system. In this study, we demonstrated that the triple chlorination of the unactivated methyl group of the carrier-protein tethered L-leucine substrate is mediated by the tandem action of two nonheme Fell halogenases, BarB1 and BarB2. I am currently investigating mechanistic aspects of halogenation of unactivated carbon centers through the investigation of pre-steady state kinetic parameters and EPR and Mossbauer investigation of metal center during the catalysis. The objective of the proposed project is mechanistic description of methylcobalamin-radical SAM enzymes that carry out methylations of sp2 carbon centers in antibiotic biosynthesis. Our goal is to understand the logic that nature uses to channel methylcobalamin, iron-sulfur clusters and deoxyadenosyl radicals to perform this novel carbon-carbon bond formation in enzymology. The methylation event will be studied in the context of generation of the 5-methylpyrrole-2-carboxylate pharmacophore in aminocoumarin antibiotic biosynthesis, and hydroxyethyl side chain in the biosynthesis of beta lactam antibiotic thienamycin. Better understanding of enzymes involved in the antibiotic biosynthesis can lead to the development of new antibiotic variants through combinatorial biosynthesis. This is especially important because of the development of bacterial resistance to commonly used antibiotics.

我已获得理学学士学位。 2000年获得塞尔维亚和黑山贝尔格莱德大学化学博士学位，2017年获得塞尔维亚和黑山贝尔格莱德大学化学博士学位。 2005 年 5 月获得伊利诺伊大学厄巴纳-香槟分校有机化学博士学位。研究中，我开发了化学选择性碳水化合物-肽连接的新方法 David Y. Gin 和 Wilfred A. van der Donk 教授的共同指导。目前，我是达蒙·鲁尼恩癌症研究基金会 Christopher T. Walsh 教授实验室的博士后研究员哈佛医学院。 HMS 和 Walsh 教授提供了出色的研究环境和致力于博士后研究员的成功。我的博士后研究重点是最近发现的一类非血红素铁的表征 (II)卤化酶，能够进行未活性碳中心的卤化。到目前为止，我们已经重建巴巴酰胺系统中的卤化活性。在这项研究中，我们证明了三重介导载体蛋白束缚的 L-亮氨酸底物的未活化甲基的氯化通过两种非血红素 Fell 卤化酶 BarB1 和 BarB2 的串联作用。我目前正在调查通过预稳态研究非活性炭中心卤化的机理催化过程中金属中心的状态动力学参数以及 EPR 和 Mossbauer 研究。拟议项目的目标是甲基钴胺素自由基 SAM 酶的机理描述在抗生素生物合成中进行 sp2 碳中心的甲基化。我们的目标是了解大自然用来引导甲钴胺、铁硫簇和脱氧腺苷自由基的逻辑在酶学中进行这种新型碳-碳键的形成。甲基化事件将在氨基香豆素抗生素中 5-甲基吡咯-2-羧酸酯药效团的产生背景 β-内酰胺抗生素硫霉素生物合成中的生物合成和羟乙基侧链。更好地了解抗生素生物合成中涉及的酶可以导致新药物的开发通过组合生物合成产生抗生素变体。这一点尤其重要，因为细菌对常用抗生素产生耐药性。