HIGH DENSITY LIPOPROTEIN STRUCTURE-FUNCTION CORRELATIONS

本研究的最终目的是阐明其结构和功能 人类高密度脂蛋白之间的关系，因为它们与 该脂蛋白的胆固醇转运作用及其保护作用 对心血管疾病的防治作用。这个项目的具体目标是 是准备各种类型的合成的、化学定义的模型 高密度脂蛋白(盘状新生高密度脂蛋白，和球形高密度脂蛋白不同的子类 大小)，并详细研究其结构和稳定性 这些重组颗粒中的主要载脂蛋白(apo A-I)，如 以及表面和核心类脂成分的物理性质。 关于这些合成的高密度脂蛋白颗粒的结构信息将是 与它们作为卵磷脂胆固醇底物的活性相关 酰基转移酶及其作为胆固醇受体的有效性 和磷脂。高密度脂蛋白的胆固醇受体作用将是 通过考察转移和平衡的动力学进一步研究 放射性标记胆固醇在供体颗粒之间的分布(非常低， 低密度脂蛋白和红细胞膜)和各种 重组高密度脂蛋白，具有明确的化学和物理特性。 这些研究将使用不同的生物物理和生化方法， 包括圆二色谱、荧光光谱、电子 显微镜、分析性超速离心法、差示扫描法 量热法、梯度凝胶电泳法、层析法和 免疫学技术。

The ultimate goal of this research is to elucidate the structure-function relationships in human high density lipoproteins (HDL), as they relate to the cholesterol transport role of this lipoprotein and to its protective effect against cardiovascular disease. The specific aims of this project are to prepare synthetic, chemically defined models of the various types of HDL (discoidal nascent HDL, and spherical HDL subclasses of different sizes) and to investigate in detail the structure and stability of the major apolipoprotein of HDL (apo A-I) in these reconstituted particles, as well as the physical properties of the surface and core lipid components. The structural information on these synthetic HDL particles will then be correlated with their activity as substrates for lecithin cholesterol acyltransferase and with their effectiveness as acceptors for cholesterol and phospholipids. The cholesterol acceptor role of HDL will be investigated further by examining the kinetics of transfer and equilibrium distribution of radiolabeled cholesterol between donor particles (very low, low density lipoproteins, and erythrocyte membranes) and various recombinant HDL, with defined chemical and physical properties. These studies will employ diverse biophysical and biochemical methods, including circular dichroism, fluorescence spectroscopy, electron microscopy, analytical ultracentrifugation, differential scanning calorimetry, gradient gel electrophoresis, chromatographic methods, and immunological techniques.