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

• 批准号: 8049287
• 负责人: Danica Galonic Fujimori
• 金额: $ 19.05万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8049287
• 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

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.

我得了B。2000年获得塞尔维亚和黑山贝尔格莱德大学化学理学学士，2000年获得博士学位。 D. 2005年5月在伊利诺伊大学厄巴纳-香槟分校的有机化学。毕业期间 研究中，我已经开发了新的方法，化学选择性碳水化合物肽连接下， 大卫教授的共同指导。杜松子酒和Wilfred A.唐克的货车。目前我是达蒙·鲁尼恩 癌症研究基金会博士后研究员在克里斯托弗T。沃尔什在 哈佛医学院。HMS和沃尔什教授提供了一个出色的研究环境， 致力于博士后研究员的成功。 我的博士后研究集中在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， 重建的卤代活性的乙酰胺系统。在这项研究中，我们证明了三重 介导载体蛋白系连的L-亮氨酸底物的未活化甲基的氯化 通过两个非血红素Fell卤化酶BarB1和BarB2的串联作用。我正在调查 非活性炭中心卤化的机理方面，通过研究预稳定 态动力学参数以及金属中心在催化过程中的EPR和穆斯堡尔谱研究。 该项目的目标是甲基钴胺素自由基SAM酶的机理描述 其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的碳-碳键的形成。甲基化事件将在 氨基香豆素类抗生素中5-甲基吡咯-2-羧酸药效团的产生背景 在β内酰胺抗生素硫霉素的生物合成中，羟乙基侧链是主要的。 更好地了解参与抗生素生物合成的酶可以导致新的抗生素的开发。 通过组合生物合成的抗生素变体。这一点尤其重要，因为 细菌对常用抗生素产生耐药性。