HIGH DENSITY LIPOPROTEIN STRUCTURE-FUNCTION CORRELATIONS

本研究的最终目的是阐明结构-功能 人类高密度脂蛋白（HDL）的关系，因为它们与 这种脂蛋白的胆固醇转运作用及其保护作用 对心血管疾病的影响。 该项目的具体目标 是准备合成的，化学定义的各种类型的模型， HDL（盘状新生HDL和不同的球形HDL亚类） 尺寸），并详细调查的结构和稳定性， 这些重构颗粒中的HDL主要载脂蛋白（apo A-I）， 以及表面和核心脂质组分的物理性质。 这些合成HDL颗粒的结构信息将被 与其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。 HDL的胆固醇受体作用将是 通过检查转移和平衡的动力学进一步研究 放射性标记的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HDL，具有明确的化学和物理性质。 这些研究将采用各种生物物理和生物化学方法， 包括圆二色性、荧光光谱、电子 显微镜，分析超离心，差示扫描 量热法，梯度凝胶电泳，色谱法，和 免疫技术。

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.