STRUCTURAL STUDIES ON ENZYMES INVOLVED IN SIALIC ACID TRANSFERASE, SULFUR ASSIMI

唾液酸转移酶硫阿西米的结构研究

基本信息

批准号：
8170091
负责人：
ANDREW J FISHER
金额：
$ 0.27万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-05-01 至 2011-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8170091
关键词：
Architecture Assimilations Bacterial Infections Bilin Biliverdine Biological Process Carbohydrates Cell physiology Computer Retrieval of Information on Scientific Projects Database Data Electron Spin Resonance Spectroscopy Electrons Enzymes Ferredoxin Funding Glycoconjugates Goals Grant Hour Inorganic Sulfates Institution Life Light Malignant Neoplasms Molecular Molecular Structure Oligosaccharides Organism Oxidoreductase Pathway interactions Photoreceptors Phycobiliproteins Phytochrome Plants Play Polysaccharides Process Regulation Research Research Personnel Resources Role Sialic Acids Sialyltransferases Source Sulfur System Therapeutic Time Transferase United States National Institutes of Health Unspecified or Sulfate Ion Sulfates chromophore enzyme mechanism enzyme structure inhibitor/antagonist mutant photosynthetic bacteria phycobilin response

项目摘要

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. 1) One system is involved in sialyltransferases, or enzymes that add sialic acid onto acceptor carbohydrates. Sialyltransferases are key enzymes that catalyze the synthesis of sialic acid-containing oligosaccharides, polysaccharides, and glycoconjugates that play pivotal roles in many physiologically and pathologically critical processes in both prokaryotic and eukaryotic organisms. Despite their important biological functions, little is known about the molecular architecture and catalytic mechanism of these enzymes. Our long-term goals of this project are to elucidate the molecular structure and catalytic mechanism of STs and to develop ST inhibitors as potent therapeutics that can be used to treat cancers and pathogenic bacterial infections. 2) Another cellular pathway the lab is investigating is in sulfur assimilation and the sulfate activation pathway. The lab has determined a number of enzyme structures in this pathway from diverse organisms using data collected at SSRL. This proposal will focus on better understanding the structural requirements for regulation of the first two enzymes in the pathway as well as subsequent enzymes involved in the synthesis of sulfur containing biomolecules. 3) Finally, a new project the lab has initiated recently is investigating the structural features on plant and photosynthetic bacteria enzymes involved in chromophore synthesis. In particular, synthesis of phytochromes that regulate many cellular processes in response to light. PcyA, a representative ferredoxin-dependent bilin reductase is responsible for the formation of phycocyanobilin (PCB), the precursor of the chromophores of the photoreceptor phytochrome and a number of phycobiliproteins. This PcyA enzyme reduces biliverdin by four electrons, and proceeds through two radical intermediates, which have been confirmed by EPR spectroscopy. We have generated mutants that extend the life time of these radicals to many hours. Radical enzyme has been formed in the crystal and confirmed by EPR.

该子项目是利用该技术的众多研究子项目之一资源由 NIH/NCRR 资助的中心拨款提供。子项目及研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金，因此可以在其他 CRISP 条目中表示。列出的机构是对于中心来说，它不一定是研究者的机构。 1) 一个系统涉及唾液酸转移酶，或将唾液酸添加到受体碳水化合物上的酶。唾液酸转移酶是催化含唾液酸的寡糖、多糖和复合糖合成的关键酶，在原核和真核生物的许多生理和病理关键过程中发挥着关键作用。尽管它们具有重要的生物学功能，但人们对这些酶的分子结构和催化机制知之甚少。我们该项目的长期目标是阐明 ST 的分子结构和催化机制，并开发 ST 抑制剂作为可用于治疗癌症和致病细菌感染的有效疗法。 2) 实验室正在研究的另一个细胞途径是硫同化和硫酸盐活化途径。该实验室利用 SSRL 收集的数据，确定了来自不同生物体的该途径中的许多酶结构。该提案将侧重于更好地了解该途径中前两种酶以及参与含硫生物分子合成的后续酶的调节结构要求。 3）最后，实验室最近启动的一个新项目正在研究参与发色团合成的植物和光合细菌酶的结构特征。特别是光敏色素的合成，调节许多细胞对光的反应过程。 PcyA 是一种代表性的铁氧还蛋白依赖性胆碱还原酶，负责形成藻蓝蛋白 (PCB)、光感受器光敏色素和许多藻胆蛋白的发色团的前体。这种 PcyA 酶将胆绿素还原为四个电子，并通过两个自由基中间体进行反应，这一点已被 EPR 光谱证实。我们已经产生了突变体，可以将这些自由基的寿命延长到几个小时。晶体中已形成自由基酶，并经 EPR 证实。