低密度脂蛋白是把胆固醇运输到肝脏合成胆酸一种重要的脂蛋白。低密度脂蛋白结构的研究对弄清动脉硬化发病机理有着非常重要的意义。用硫酸铵分离法快速分离鸡蛋黄中各种蛋白成分,用Sephadex G-200柱层析分离、纯化获得纯度很高的低密度脂蛋白,对其进行SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)检测,结果显示低密度脂蛋白主要包含5种脱辅基蛋白。激光拉曼和红外光谱测定,检测出低密度脂蛋白中对称CH2以及不对称CH2的伸缩振动。红外光谱还检测到脂蛋白肽键中C=O伸缩振动、脂链中P=O的伸缩振动和磷脂中胆碱聚集体的N+(CH3)3的不对称振动。两种光谱分析为研究低密度脂蛋白的结构提供了有效信息。
During the experiment,diversified proteins were separated from hen egg yolk by ammonium sulphate rapid fractionation,and pure LDL was obtained after filtrating through Sephadex G-200 chromatography.After the qualitative detection of SDS-PAGE,the authors discovered that LDL consists of five major apoprotein.The Raman and infrared spectrum showed CH2 asymmetric stretching and symmetric stretching mode.However,the authors found C=O stretching vibrations of protein peptide bonds and N+(CH3)3 asymmetric stretching vibration from the choline group in phospholipids.Laser Raman and infrared spectrum analysis of LDL provided useful information for studying their structure.