Functionalization of unactivated sp2-hybridized carbon atoms

未活化的 sp2 杂化碳原子的官能化

• 批准号: 8880248
• 负责人: JOSEPH M BOLLINGER
• 金额: $ 37.46万
• 依托单位: PENNSYLVANIA STATE UNIVERSITY, THE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-02 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8880248
• 关键词: Adenosine; Aerobic Bacteria; Anabolism; Anti-Bacterial Agents; Antibiotics; Aromatic Amino Acids; Biochemical Reaction; Biological Factors; Carbon; Characteristics; Chemicals; Cleaved cell; Cobalamin; Complex; Deuterium; Dioxygenases; Dissociation; Enzymes; Ethnic group; Event; Family; Goals; Heme; Homocysteine; Homocystine; Hydrogen; Hydrogen Bonding; Hydroxylation; Insulin-Dependent Diabetes Mellitus; Iron; Isotopes; Kinetics; Lysine; Mediating; Methane; Methane hydroxylase; Methods; Methylation; Methyltransferase; Mixed Function Oxygenases; Modification; Mole the mammal; Mononuclear; Nature; Oxidants; Oxygenases; Particulate; Pharmaceutical Preparations; Process; Proteins; Pterins; Reaction; Reducing Agents; Risk Factors; Role; S-Adenosylmethionine; Scheme; Specific qualifier value; Therapeutic; Thiostrepton; Tracer; Transfer RNA; Transition Elements; Tryptophan; Xanthines; abstracting; alpha ketoglutarate; base; cobamamide; cofactor; design; enzyme mechanism; inhibitor/antagonist; lipoate; quinaldic acid

DESCRIPTION (provided by applicant): Nature has evolved a variety of strategies to cleave unactivated carbon-hydrogen bonds in order to functionalize inert carbon centers. These reactions invariably employ metallocofactors to create powerful oxidants that can abstract hydrogen atoms from the carbon centers to be functionalized, generating carbon-centered radicals. In all well-established enzyme mechanisms involving H• abstraction, the cleaved C-H bonds are sp3-hybridized, and the associated homolytic bond-dissociation energies (BDEs) are less than (or equal to) the 104 kcal/mol characteristic of methane. Recently, a growing number of reactions have been identified that imply functionalization of carbon centers that are sp2-hybridized with cleavage of bonds that have BDEs of greater than 105 kcal/mol. This project aims to characterize three such enzymatic reactions involving methylation, methylthiolation, and hydroxylation of sp2-hybridized carbon centers. The first two reactions are catalyzed by enzymes belonging to the radical-SAM superfamily, while the third is catalyzed by an enzyme in the Fe(II)- and α-ketoglutarate-dependent oxygenase family. The results of these studies should significantly expand our understanding of Nature's strategies for functionalization of unactivated sp2-hybridized carbon centers and reveal details of reaction mechanisms that may prove practically useful in design of therapeutic inhibitors of these processes.

描述（由申请人提供）：大自然已经发展出多种策略来裂解未活化的碳-氢键，以使惰性碳中心功能化。这些反应总是利用金属辅因子来产生强大的氧化剂，可以从碳中心提取氢原子进行功能化，产生以碳为中心的自由基。在所有涉及 H• 提取的成熟酶机制中，裂解的 C-H 键都是 sp3 杂化的，相关的均裂键解离能 (BDE) 小于（或等于）甲烷的 104 kcal/mol 特征值。最近，越来越多的反应已被确定，这些反应意味着 sp2 杂化的碳中心的官能化，以及 BDE 大于 105 kcal/mol 的键的断裂。该项目旨在表征涉及 sp2 杂化碳中心的甲基化、甲硫基化和羟基化的三种此类酶反应。前两个反应由属于自由基 SAM 超家族的酶催化，而第三个反应由 Fe(II) 和 α-酮戊二酸依赖性加氧酶家族的酶催化。这些研究的结果将显着扩展我们对 Nature 未活化 sp2 杂化碳中心功能化策略的理解，并揭示反应机制的细节，这些细节可能在设计这些过程的治疗性抑制剂时实际有用。

项目成果

Trifluoroselenomethionine: A New Unnatural Amino Acid.

• DOI: 10.1002/cbic.201600266
• 发表时间: 2016-09-15
• 期刊: Chembiochem : a European journal of chemical biology
• 作者: Block E;Booker SJ;Flores-Penalba S;George GN;Gundala S;Landgraf BJ;Liu J;Lodge SN;Pushie MJ;Rozovsky S;Vattekkatte A;Yaghi R;Zeng H
• 通讯作者: Zeng H

Transformations of the FeS Clusters of the Methylthiotransferases MiaB and RimO, Detected by Direct Electrochemistry.

• DOI: 10.1021/acs.biochem.6b00670
• 发表时间: 2016-10-04
• 期刊: Biochemistry
• 影响因子: 2.9
• 作者: Maiocco SJ;Arcinas AJ;Landgraf BJ;Lee KH;Booker SJ;Elliott SJ
• 通讯作者: Elliott SJ