Structural and functional studies of lecithin:cholesterol acyltransferase

卵磷脂：胆固醇酰基转移酶的结构和功能研究

基本信息

批准号：
9269074
负责人：
Kelly A Manthei
金额：
$ 5.92万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9269074
关键词：
Active Sites Alveolar Macrophages Apolipoprotein A-I Binding Binding Sites Biochemical Biological Response Modifier Therapy Cardiovascular Diseases Catalysis Catalytic Domain Cholesterol Clinical Clinical Research Collaborations Complex Corneal Opacity Coronary heart disease Cryoelectron Microscopy Crystallization DNA Sequence Alteration Data Deficiency Diseases Disease Elements Enzyme Activation Enzymes Event Eye diseases Fishes Goals Heart Diseases Hereditary Disease High Density Lipoprotein Cholesterol High Density Lipoproteins Homologous Gene Lipoprotein (a)Liver Mediating Modeling Molecular Mutate Mutation Phosphatidylcholine-Sterol O-Acyltransferase Phospholipase A2 Positioning Attribute Process Protein Region Proteins Recombinants Reporting Resolution Role Site Sphingosine Structure Testing Therapeutic Transport Process Variant X-Ray Crystallography analog design enzyme replacement therapy familial cholesteryl ester deficiency high risk improved lecithin cholesterol acyltransferase deficiency mutant particle peptidomimetics public health relevance reverse cholesterol transport small molecule therapeutic target tool

项目摘要

DESCRIPTION (provided by applicant): Lecithin:cholesterol acyltransferase (LCAT) esterifies cholesterol in high density lipoprotein (HDL), which promotes HDL maturation in reverse cholesterol transport, the process by which cholesterol is moved from arterial plaques to the liver. Mutations in LCAT cause two genetic diseases, both of which are characterized by low HDL-cholesterol (HDL-C) levels. Furthermore, clinical studies have shown that low HDL-C is associated with high risk for coronary heart disease (CHD). Consequently, administration of recombinant LCAT and LCAT activating compounds are being investigated as treatments to increase HDL in both CHD and LCAT genetic disease. However, improvement of these therapeutics is limited due to a lack of structural information on LCAT. The objective of this proposal is to determine the molecular basis for LCAT activation and the structural elements required for cholesterol recognition through the use of X-ray crystallography and cryo-electron microscopy in parallel with functional studies. The first aim will focus on functional characterization of a new crystal form of LCAT wherein a retractable lid that seems to block the active site. Interestingly, the lid interacts with residues on the catalytic core of LCAT known to be important for activation by apolipoprotein A-I (ApoA-I), the major protein component of HDL particles, suggesting that ApoA-I binding may displace the lid to stimulate LCAT activity. In the second aim, I will investigate the molecular basis for LCAT acyl acceptor selectivity and for activation by a small molecule activator through combined crystallographic and biochemical studies. LCAT crystal structures will be determined in complex with acceptor analogs and/or small molecule activators, and residues in the active site that differ between LCAT and a closely related enzyme will be mutated to test whether substrate selectivity can be exchanged. Overall, these studies are expected to pave the way for the design of more potent small molecule activators as well as more catalytically efficient LCAT for use in enzyme replacement therapy for the treatment of CHD and/or genetic disease.

描述（通过应用程序证明）：卵磷脂：胆固醇ACHLTRASSFRESTRASE（LCAT）在高密度脂蛋白（HDL）Motes HDL Materse中酯化胆固醇的胆固醇在反向胆固醇中，胆固醇从动脉滴虫转移到了liver的过程中。 DL-C的水平与冠心病的高风险相关。 LCAT上的结构掺入。 LCAT盖子的新晶体形式的表征似乎阻塞了活性位点。，表明ApoA-I结合可能会刺激LCAT的行为，并通过晶体学和生物化学研究结合使用激活剂。密切相关的酶将使底物是否可以交换底物。这些研究预计将为设计更有效的小分子以及更多的Catale Caticule caticule Efficille lcat铺平遗传疾病。