LIPOPROTEIN STRUCTURE AND APOPROTEIN CONFORMATION

该项目的主要目标是提供详细的结构， 分子组织的构象和动态信息， 血浆脂蛋白中脂质和载脂蛋白的相互作用 （主要是HDL和LDL） 研究重点是高分辨率结构 研究特定的载脂蛋白和脂蛋白， 最先进的结构生物学方法 探索的主要领域 关注：a.完整脂蛋白（HDL， 低密度脂蛋白），重点是脱辅基蛋白的分子构象 脂蛋白表面，和B.详细的分子构象和 载脂蛋白（AI和B）的结构。 载脂蛋白研究 AI将采用多种方法来识别 序列中重要的结构和功能元件。 合成 肽将用于模拟这些区域。 详细的分子 构象和热力学稳定性将通过建模，X- 射线晶体学、2D NMR、CD和量热法。 此外 天然脱辅基蛋白的详细分子结构将通过 X射线晶体学 载脂蛋白B的研究将集中在结构域 蛋白质的折叠以及蛋白质的构象和功能 子域。 蛋白酶切割和分子生物学方法将是 用于获得代表这些结构的apoB序列片段， 域. 天然LDL的结构研究，通过冷冻电子显微镜 将重点关注apoB的组织和结构定位， 和LDL颗粒上的功能结构域， 纳米金标记。 对脱辅基蛋白的详细分子认识 构象和结构对于进一步理解 脂蛋白的结构和功能 从这份报告中获得的信息 该项目将导致对分子的更好理解 HDL和LDL的组织和相互作用。 更重要的是， 提供基本的背景资料，以了解 生理和代谢过程，如脂蛋白细胞表面 相互作用，脂蛋白相互转化和催化剂在一个真正的 分子水平。

The major objectives of this project are to provide detailed structural, conformational and dynamic information on the molecular organization and interactions of lipids and apoproteins in the plasma lipoproteins (primarily HDL and LDL). Studies focus on high resolution structural investigations of specific apoproteins and lipoproteins using state-of- the-art methodologies of structural biology. The primary areas explored concern: a. the three dimensional structure of intact lipoproteins (HDL, LDL) with emphasis on the molecular conformation of the apoproteins of the lipoprotein surface, and b. the detailed molecular conformation and structure of the apolipoproteins (AI and B). Studies of apolipoproteins AI will employ a combination of methodologies for the identification of important structural and functional elements in the sequence. Synthetic peptides will be used to model these regions. The detailed molecular conformation and thermodynamic stability will be studied by modelling, X- ray crystallography, 2D NMR, CD, and calorimetry. In addition the detailed molecular structure of the native apoproteins will be studied by X-ray crystallography. Studies of apoprotein B will focus on the domain folding of the protein and the conformation and function of the subdomains. Protease cleavage and molecular biology approaches will be used to obtain segments of the apoB sequence representing these structural domains. Structural studies of native LDL, by cryo electron microscopy will focus on the organization of apoB and the localization of structural and functional domains on the LDL particle using a combination of immuno- nanogold labelling. A detailed molecular understanding of apoprotein conformation and structure is vital to further progress in understanding lipoprotein structure and function. The information derived in this project will result in an improved understanding of the molecular organization and interactions in HDL and LDL. More importantly, they will provide basic background information essential to understanding physiological and metabolic processes such as lipoprotein cell surface interactions, lipoprotein interconversion and catabolism at a truly molecular level.