The structural basis for cholesterol esterification in human plasma

人血浆中胆固醇酯化的结构基础

• 批准号: 10450679
• 负责人: W Sean Davidson
• 金额: $ 48.66万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10450679
• 关键词: Address; Apolipoprotein A-I; Apolipoprotein A-II; Apolipoprotein E; Apolipoproteins; Apolipoproteins B; Attenuated; Binding; Binding Sites; Biological Assay; Blood Circulation; Brain; Cardiovascular Diseases; Chemicals; Cholesterol; Cholesterol Esters; Complex; Cryoelectron Microscopy; Crystallization; Deposition; Disease; Docking; Electron Microscopy; Epitopes; Equilibrium; Esterification; Face; Fatty Acids; Fatty acid glycerol esters; Fluorescence; Genetic; Genetic Diseases; High Density Lipoproteins; Human; Image; Individual; Inflammatory; Kidney Failure; Knowledge; Laboratories; Lecithin; Lipids; Lipoproteins; Location; Low-Density Lipoproteins; Mass Spectrum Analysis; Mediating; Metabolism; Molecular; Molecular Conformation; Mutagenesis; Nucleosome Core Particle; Organ; Participant; Peptides; Phospholipase; Plasma; Play; Production; Proteins; Reaction; Recombinants; Registries; Roentgen Rays; Role; Running; Scientist; Series; Site; Site-Directed Mutagenesis; Structural Models; Structure; Surface; Surface Plasmon Resonance; System; Testing; Therapeutic; Transferase; Translating; Triglycerides; Very low density lipoprotein; Work; cofactor; crosslink; design; experimental study; fish eye disease; interest; novel; particle; rational design; tool

Lecithin:cholesterol acyl transferase (LCAT) catalyzes the esterification of a fatty acid to cholesterol and is responsible for the majority of cholesteryl ester (CE) in the human circulation. Its activity is dramatically enhanced by cofactor apolipoproteins such as apolipoprotein (apo)A-I in HDL and apoE in LDL/VLDL and brain lipoproteins. While this cofactor relationship has been known for decades, our understanding of how apolipoproteins activate LCAT remains limited. Our preliminary work has shown that LCAT interacts with two mirror image docking sites within apoA-I that are composed of helix 4 in one apoA-I molecule and helix 6 of the opposing molecule. When this registry is disrupted, LCAT can still bind HDL but no longer catalyzes CE formation. We hypothesize that these docking sites orient LCAT with respect to the lipid faces of HDL particles and may form a conduit by which the particle core is accessed for deposition of CE. Additionally, we suspect that these sites direct the cholesterol substrate to the site of LCAT interaction via specific recognition sequences. We also believe that apoA-II, another highly abundant HDL apolipoprotein, disrupts this interaction to reduce LCAT activity. Leveraging new experimental tools developed in our laboratory, we will; 1) define the molecular mechanism for apoA-I activation of LCAT and the role of these interaction sites, 2) determine how apoA-II attenuates the LCAT reaction and 3) define the mechanism behind apoE stimulation of LCAT. This work will answer nearly 50 year old questions about how apolipoproteins enhance LCAT’s ability mediate plasma cholesterol esterification. In addition, we will translate this knowledge into the design of novel bi-helical peptides that may form a basis for treating individuals with genetic partial deficiencies of LCAT activity such as Fish Eye Disease (FED).

卵磷脂：胆固醇酰基转移酶（LCAT）催化脂肪酸的酯化为 胆固醇并负责人类的大多数胆汁胆固醇（CE） 循环。辅助因子载脂蛋白（例如 HDL中的载脂蛋白（APO）A-I和LDL/VLDL和脑脂蛋白中的APOE。同时 数十年来，辅助因子的关系已经闻名，我们对载脂蛋白的理解 激活LCAT仍然有限。我们的初步工作表明LCAT与两个相互作用 ApoA-I中由螺旋4组成的镜像图像对接位点一个apoA-i分子 和相对分子的螺旋6。当该注册表中断时，LCAT仍然可以绑定HDL 但不再催化CE的形成。我们假设这些对接站点的Orient LCAT 关于HDL颗粒的脂质面，可能形成一个导管 核心将访问CE的沉积。此外，我们怀疑这些站点指导 胆固醇底物通过特定的识别序列与LCAT相互作用的位点。我们 还认为，另一个高度丰富的HDL载脂蛋白Apoa-II破坏了这一点 相互作用以减少LCAT活性。利用我们开发的新实验工具 实验室，我们将； 1）定义了LCAT和APOA-I激活的分子机制 这些相互作用位点的作用，2）确定apoA-II如何减弱LCAT反应和3） 定义LCAT刺激的机制。这项工作将近50年 关于载脂蛋白如何增强LCAT的能力介导等离子胆固醇的旧问题 酯化。此外，我们将把这些知识转化为新型双螺旋的设计 可能构成患有LCAT遗传局部缺陷个体的基础的肽 诸如鱼眼病（FED）之类的活动。