Structural biology of biotin-dependent carboxylases

生物素依赖性羧化酶的结构生物学

基本信息

批准号：
8008942
负责人：
VIVIEN YEE
金额：
$ 6.2万
依托单位：
CASE WESTERN RESERVE 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：
2010-01-15 至 2010-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8008942
关键词：
Acidity Active Sites Address Affect Amino Acid Substitution Amino Acids Animal Welfare Bacteria Bibliography Binding Biochemical Biological Models Biotin Carbon Dioxide Carboxyltransferases Catabolism Catalysis Catalytic Domain Cobalt Complex Country Critiques Crystallization Data Decarboxylation Dependence Disease Environment Environmental Impact Enzymes Equipment Fatty Acids Genes Gluconeogenesis Human IACUC Image In Vitro International Ions Label Lead Ligand Binding Ligands Metabolic Metabolic Diseases Metabolic Pathway Methods Methylmalonyl-CoA carboxyltransferase Missense Mutation Monitor Multienzyme Complexes Mutation N1&apos -carboxybiotin Nature Outcome Oxaloacetates Patients Play Population Preparation Principal Investigator Propionic Acids Proteins Protons Publishing Pyruvate Pyruvates Raman Spectrum Analysis Reaction Relative (related person)Research Research Design Research Ethics Committees Resolution Resources Role Sampling Shapes Site-Directed Mutagenesis Spectrum Analysis Staining method Stains Stretching Structure Techniques Testing Vertebrates Yeasts abstracting biotin 2 carbon dioxide transport carboxylation cofactor deprotonation design developmental disease enolate enzyme deficiency expiration human subject inhibitor/antagonist ketotic hyperglycinemia lactic acidemia methylmalonyl-CoA decarboxylase novel oxidation particle programs propionyl-coenzyme A protein folding research study response structural biology tiglyl-coenzyme A tool

项目摘要

Biotin-dependent carboxylases use a covalently attached biotin cofactor to transport carbon dioxide as carboxybiotin. Four human biotin-dependent carboxylases have been identified, and play central roles in metabolic pathways such as oxidation of odd-chain fatty acids, catabolism of branched amino acids, fatty acid synthesis, and gluconeogenesis. The bacterial transcarboxylase enzyme has long served as a model system for the human biotindependent carboxylases. This proposal focuses on structure-function studies of transcarboxylase and on two human enzymes, propionyl coenzyme A carboxylase and methylcrotonoyl coenzyme A carboxylase. The broad objective is to provide structural information for these enzymes in order to better understand their assembly as multi-enzyme complexes and their mechanisms of catalytic activity. The specific aims are to: 1. To probe the chemistry and mechanism of the transcarboxylase active sites with structural studies of the isolated 12S and 5S subunits. Crystals of the isolated subunits bound to substrate, product, or cofactor will be studied by X-ray crystallography and Raman crystallography. Site- directed mutagenesis will be used to probe the importance of residues highlighted by structural studies. 2. To probe the molecular architecture of the intact transcarboxylase multienzyme complex by X-ray crystallography and electron microscopy. 3. To investigate the crystal structure of human propionyl coenzyme A carboxylase and to model the possible structural consequences of deficiency mutations in the metabolic disorder propionic acidemia. 4. To investigate the crystal structure of the human methylcrotonyl coenzyme A carboxylase beta subunit and to model the possible structural consequences of deficiency patients with the metabolic disorder 3-methylcrotonylglycinuria. Relevance: Biotin-dependent enzymes are important in human metabolism. Mutations which alter their genes are found in patients with metabolic and developmental disorders. Investigating the structures of these enzymes will aid understanding of how these proteins assemble and function, and help explain how mutations may cause disease.

生物素依赖性羧酸酶使用共价附着的生物素辅因子将二氧化碳作为羧酸氧化碳。四个人类生物素依赖性羧化酶已经被鉴定出来，并在代谢途径中起着核心作用，例如奇数链脂肪酸的氧化，分支氨基酸的分解代谢，脂肪酸合成和糖生成。细菌转羧化酶长期以来一直是人类生物独立羧化酶的模型系统。该建议的重点是转羧酸酶和两个人类酶的结构功能研究。羧化酶。广泛的目标是为这些酶提供结构信息，以便更好地理解它们作为多酶复合物及其催化活性机制。具体目的是：1。探测转羧酸酶的化学和机理具有分离的12s和5s亚基的结构研究的活性位点。 X射线晶体学和拉曼晶体学研究将研究与底物，产物或辅因子结合的分离亚基的晶体。定位的诱变将用于探测结构研究突出显示残基的重要性。 2。通过X射线晶体学和电子显微镜探测完整的转羧酸酶多酶复合物的分子结构。 3。研究人丙酶A羧化酶的晶体结构，并模拟代谢疾病丙酸血症缺乏突变的可能结构后果。 4。研究晶体结构人类甲基杂菌辅酶A羧化酶β亚基，并模拟代谢疾病3-甲基氯尼氏糖尿病的缺乏症患者的可能结构后果。相关性：依赖生物素的酶在人类代谢中很重要。改变其基因的突变是在代谢和发育障碍患者中发现的。研究这些酶的结构将有助于理解这些蛋白质如何组装和起作用，并有助于解释突变如何引起疾病。