Structural Thermodynamics of Human Apolipoprotein C-1

超出空间 但前提是。 这个项目的长期目标是详细确定分子的能量结构和功能 可交换载脂蛋白和脂蛋白的关系，从而提供了对分子的洞察 脂蛋白在动脉粥样硬化及其他脂蛋白相关疾病发病中的作用机制 疾病。可交换载脂蛋白是调节脂质的脂蛋白的可溶蛋白质组分 和胆固醇的运输和代谢，并在动脉粥样硬化的发病机制中发挥关键作用， 冠心病、中风等人类重大疾病。结构稳定性和成分 脂蛋白的可变性对其功能是必不可少的，必须详细了解才能 阐明脂蛋白在正常和疾病状态下作用的分子机制。拟议中的工作 通过对能量、结构和脂质结合功能的详细研究来解决这一长期目标 两个小的人类血浆载脂蛋白，apoC-1和apoA-2。ApoC-1推迟清除潜在的 通过抑制载脂蛋白E介导的低密度脂蛋白摄取富含甘油三酯的动脉粥样硬化颗粒 受体相关途径。载脂蛋白C-1激活卵磷脂：胆固醇酰基转移酶的能力可能 解释主要LCAT缺乏者的血浆胆固醇酯正常水平 激活剂，载脂蛋白A-1。载脂蛋白A-2从高密度脂蛋白(HDL)中取代载脂蛋白A-1的能力会影响 高密度脂蛋白的抗动脉粥样硬化作用。脱脂和脂结合人体的能量和结构分析 将进行apoA-2、apoC-1和一系列针对关键结构区域的apoC-1突变体 通过使用远紫外圆二色谱和近紫外圆二色谱和荧光光谱的组合，电子 显微镜、差示扫描量热法和x射线衍射法。这种分析将确定，在 单个氨基酸的水平，载脂蛋白C-1的关键结构元素对其折叠、稳定性和 脂类结合特性；确定脂蛋白稳定性的关键决定因素及其与脂蛋白动力学的关系 载脂蛋白在脂蛋白代谢过程中的脂蛋白转移；结晶载脂蛋白C-1和 分析其晶体结构，可能为研究载脂蛋白的功能构象提供模型。这个 这些结果将为理解脂蛋白的分子机制提供能量和结构基础 在正常和患病状态下的动作。

EXCEED THE SPACE PROVIDED. The long-term objective of this project is to determine in molecular detail the energetic-structure-function relationship in exchangeable apolipoproteins and lipoproteins, thereby providing an insight into molecular mechanisms of lipoprotein action in the pathogenesis of atherosclerosis and other Upoprotein-related diseases. Exchangeable apolipoproteins are soluble protein components of lipoproteins that mediate lipid and cholesterol transport and metabolism and play crucial roles in the pathogenesis of atherosclerosis, coronary heart disease, stroke and other major human disorders. Structural stability and compositional variability of lipoproteins are essential for their functions, and have to be understood in detail in order to elucidate molecular mechanisms of lipoprotein action in normal and in diseased states. The proposed work addresses this long-term goal through detailed studies of the energetics, structure and lipid binding function of two small human plasma apolipoproteins, apoC-1 and apoA-2. ApoC-1 delays the clearance of potentially atherogenic triglyceride-rich particles by inhibiting their uptake via the apoE-mediated low-density lipoprotein receptor-related pathway. The ability of apoC-1 to activate lecitin:cholesterol acyltransferase (LCAT) may account for normal plasma levels of cholesterol esters in subjects with deficiency of the major LCAT activator, apoA-1. ApoA-2 ability to displace apoA-1 from high-density lipoproteins (HDL) affects the antiatherogenic functions of HDL. Energetic and structural analyses of lipid-free and lipid-bound human apoA-2, apoC-1 and a series of apoC-1 mutants targeted towards key structural regions will be carried out by using a combination of far- and near-UV circular dichroism and fluorescence spectroscopy, electron microscopy, differential scanning calorimetry, and x-ray diffraction methods. Such analysis will determine, at the level of individual amino acids, the roles of key structural elements in apoC-1 for its folding, stability and lipid binding properties; identify critical determinants for the Lp stability and their relation to the kinetics of apolipoprotein transfer among lipoproteins in the course of lipoprotein metabolism; crystallize apoC-1 and analyze its crystal structure that may provide a model for a functional apolipoprotein conformation. The results will provide the energetic and structural basis for understanding molecular mechanisms of lipoprotein action in normal and diseased states.