Regulation and Catalysis of Human Insulin Degrading Enzyme

人胰岛素降解酶的调控与催化

• 批准号: 7898366
• 负责人: WEI-JEN TANG
• 金额: $ 24.02万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-31 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7898366
• 关键词: Address; Affinity; Alanine; Alzheimer' s Disease; Amyloid; Animals; Atrial Natriuretic Factor; B-insulin; Binding; Biochemical; Brain; C-terminal; Catalysis; Catalytic Domain; Cell Culture Techniques; Cell Line; Cells; Cerebrum; Charge; Complex; Crystallization; Culture Media; Cultured Cells; Cysteine; Data; Development; Diabetes Mellitus; Dimerization; Disulfides; Drug Delivery Systems; Effectiveness; Encapsulated; Engineering; Enzyme Gene; Enzyme Inhibitor Drugs; Enzyme Inhibitors; Enzymes; Failure; Family; Florida; Frequencies; Future; Genetic; Glucagon; Human; In Vitro; Insulin; Insulinase; Ions; Kinetics; Knowledge; Lead; Metalloproteases; Modeling; Molecular; Molecular Conformation; Mus; Mutation; Neuroblastoma; Neurons; Non-Insulin-Dependent Diabetes Mellitus; Peptide Hydrolases; Peptides; Point Mutation; Process; Property; Proteins; Proteolysis; Recombinants; Reducing Agents; Regulation; Research Personnel; Resolution; Rodent; Role; Scanning; Structural Models; Structure; Subfamily lentivirinae; Testing; Therapeutic; Transfection; Universities; Work; Zinc; base; design; dimer; disulfide bond; enzyme activity; enzyme structure; enzyme substrate; enzyme substrate complex; hydroxamate; improved; inhibitor/antagonist; insight; islet amyloid polypeptide; loss of function mutation; mouse model; mutant; novel; overexpression; oxidation; peptidomimetics; preference; prevent; programs; protein structure; research study; success; therapeutic target; tool; tris(2-carboxyethyl)phosphine

Metalloprotease is the most abundant within the five protease classes in humans. Insulin degrading enzyme (IDE) is a zinc-metalloprotease that is involved in the clearance of insulin and amyloid (3 (A3), two key proteins for the development of diabetes and Alzheimer's disease, respectively. Accumulating genetic evidence strongly suggests that IDE is a potential drug target for type 2 diabetes and Alzheimer's disease. In order to develop tools to explore the therapeutic potential of IDE, we have recently solved the x-ray crystal structures of human IDE in complex with insulin B chain, Ap, amylin, and glucagon at 2.1-2.6A resolution. Our structures reveal a novel mechanism for substrate recognition and control of catalysis of IDE. Specifically, we found that IDE consists of two 56kDa functional N- and C-terminal domains (IDE-N and IDE- C, respectively) and they form an enclosed cage just large enough to encapsulate small peptides such as insulin. The extensive contacts between IDE-N and IDE-C keep the degradation chamber of IDE inaccessible to substrates. IDE stays in this closed conformation normally and the repositioning of IDE domains is the key control step in allowing substrate access to the catalytic chamber. The enclosed substrate undergoes conformational changes to interact with two discrete regions of IDE for its degradation. In this application, we propose to better understand this intriguing regulation. We will perform mutagenic analysis to begin to address the opening process as well as determine the structures of two key steps for the catalytic cycle of IDE, substrate-free IDE closed and open conformations. We will also obtain the structural basis in how IDE recognizes disulfide-bond containing IDE substrates and high affinity peptidomimetic hydroxamates that can potently inactivate IDE activity. Furthermore, we propose to construct hyperactive IDE mutants and test their ability to degrade Ap in cultured neuronal cells. Success of these aims will not only broaden our knowledge in how proteases recognize their substrates and control their proteolytic activity but also provide valuable information in the future design of IDE-based therapeutics.

金属蛋白酶是人体五类蛋白酶中含量最多的。胰岛素降解酶