STRUCTURE AND LIPID BINDING OF HUMAN APOLIPOPROTEIN

人载脂蛋白A-IV是一种新发现的血浆糖蛋白。 起源于肠道，具有几种独特和不同寻常的特性。虽然 其代谢功能目前尚不清楚，初步研究表明 它可能在肠道对脂质的吸收中起重要作用 富含甘油三酯的颗粒与高密度脂蛋白的血管内相互作用。 这项工作的目的是检查结构特征 人载脂蛋白A-IV体外脂结合特性的研究 它的生物行为。 载脂蛋白A-IV的结构和构象将通过荧光检测 以及各种实验条件下的CD光谱分析。脂类 利用Well体外研究载脂蛋白A-IV的缔合特性 磷脂-甘油三酯乳剂(Trp)AS的表征颗粒 乳酸菌模型。影响载脂蛋白A-IV亲和力的因素 这些粒子将被确定。其他纯化血浆的影响 载脂蛋白A-IV和色氨酸相互作用的载脂蛋白将被检测 研究载脂蛋白A-IV从表面移位的机制 这些粒子中。最后，探讨了影响载脂蛋白亲和力的因素。 人类高密度脂蛋白的A-IV将在体外进行检测，关于增加 载脂蛋白A-IV与某些人异常脂蛋白的亲和力 疾病。 这些拟议的研究的意义在于，它们将开发出新的 对此的结构和生物物理性质的认识很差 研究了载脂蛋白。这项调查的长期目标是 肠道载脂蛋白在调节血管紧张素转换酶活性中的作用 脂蛋白代谢，并在动脉粥样硬化的过程中。

Human apolipoprotein A-IV is a newly described plasma glycoprotein of intestinal origin, with several distinct and unusual properties. Although its metabolic function is unknown at present, preliminary studies indicate that it may play an important role in the intestinal absorption of lipids and the intravascular interaction of trigly-ceride-rich particles and HDL. It is the purpose of this work to examine the structural characteristics and in vitro lipid binding properties of human apo A-IV to gain insight into its biologic behavior. The structure and conformation of apo A-IV will be examined by fluorescence and CD spectropscopy under a variety of experimental conditions. The lipid associating properties of apo A-IV will be studied in vitro using well characterized particles of a phospholipid-triglyceride emulsion (TRP) as model chylomicrons. Factors which influence the affinity of apo A-IV for these particles will be determined. The influence of other purified plasma apoproteins on the interaction of apo A-IV and TRP will be examined to investigate the mechanism by which apo A-IV is displaced from the surface of these particles. Finally, the factors influencing the affinity of apo A-IV for human HDL will be examined in vitro, with regard for the increased affinity of apo A-IV for the abnormal lipoproteins found in certain human diseases. The significance of these proposed studies is that they will develop new knowledge of the structural and biophysical properties of this poorly studied apoprotein. The long range goal of this investigation is the elucidation of the role of intestinal apoproteins in the modulation of lipoprotein metabolism, and in the process of artherosclerosis.