【摘要】 用硫酸右旋糖酐沉淀法结合角头密度梯度超离心法,从混合人血清中提取出极低密度脂蛋白（VLDL）和高密度脂蛋白（HDL）。脱脂后用层析聚焦分离纯化其中的apoA-Ⅰ和apoC-Ⅲ,均呈现一条带,其分子量分别为28 183和9440 Dalton。等电点聚焦电泳鉴定apoA-Ⅰ有8种多态型。其主要多态型的等电点为5.66～5.87。apoC-Ⅲ的三种异构蛋白apoC-Ⅲ₀、C-Ⅲ₁和C-Ⅲ₂的等电点分别为5.06、4.88和4.72。层析聚焦方法简便,分离效果好,速度快,对于HDL和VLDL中主要载脂蛋白的分离、纯化有一定的应用价值。更多还原

【Abstract】 Human very low density lipoprotein （VLDL） and high density lipoprotein （HDL） were isolated and purified by a process of combined dextran sulfate precipitation and density gradient ultracentrifugation.Chromatofocusing, which separates protein based on differences in isoelectric point,was used to separate apolipoprotein A-Ⅰ （apoA-Ⅰ） and apolipoprotein C-Ⅲ from human HDL and VLDL,respectively. Discontinuous SDS-polyacrylamide gel electrophoresis （SDS-PAGE） and analytical isoelectric focusing （IEF） were used to study the purity of different fractions.Both purified apoA-Ⅰ and apoC-Ⅲ showed single bands on SDS-PAGE at molecular weights of 28183 and 9400 Daltons,respectively. As determined by IEF in the presence of 8 mol/L urea,apoA-Ⅰ had eight isoforms with pⅠ of 5.66—5.87.The pⅠ’s of the three isoproteins of apoC-Ⅲ （C-Ⅲ₀,C-Ⅲ₁ and C-Ⅲ₂） were 5.06,4.88 and 4.72,respectively Chromatofocusing,a new simple technique combining the high resolving power of IEF with the high capacity of ionexchange column chromatography,is extremely valuable for large-scale purification of the major apolipoproteins of VLDL and HDL.更多还原