Plasma very low density lipoproteins contain a single molecule of apolipoprotein B.
Plasma very low density lipoproteins contain a single molecule of apolipoprotein B.
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发表时间：
1988-11
影响因子：
6.5
通讯作者：
John Elovson;J. Chatterton;G. Bell;V. N. Schumaker;Michael A. Reuben;D. L. Puppione;J. Reeve;Nancy L. Young
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文献类型：
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作者：
John Elovson;J. Chatterton;G. Bell;V. N. Schumaker;Michael A. Reuben;D. L. Puppione;J. Reeve;Nancy L. Young
大鼠和人类极低密度脂蛋白（VLDL）的分级分区ultracentraggation，产生明确定义的馏分与狭窄的沉降极限。在两种密度下用分析超离心法测定各个级分的沉降系数，并对结果进行分析，以获得每个级分中颗粒的浮力密度和分子量。对于大鼠脂蛋白，测定各组分的甘油三酯、胆固醇、磷脂和蛋白质的重量浓度，并采用放射免疫测定法测定其载脂蛋白B的摩尔浓度。对于人脂蛋白，相应的值取自Patsch等人（Patsch，W.，J. R. Patsch，G. M. Kostner，S. Sailer和H.布劳恩斯泰纳。1978.人极低密度脂蛋白亚组分的区带超离心分离。J.Biol.Chem.253：4911 - 4915）。根据这些数据，计算每个级分的apoB肽的数量与脂蛋白颗粒的数量的比率。对于所有VLDL组分，该比率接近1，对于大鼠和人VLDL，颗粒直径分别为约40至80 mm和30至50 mm。大多数大鼠VLDL含有B-48而不是B-100作为它们的（单个）apo B肽。基于这些数据，我们提出，只有一个拷贝的B-48所需的VLDL组装在大鼠肝脏中，除非新生的肝VLDL含有额外的apo B肽，从血浆VLDL颗粒均匀丢失时，他们进行了分析。
Rat and human very low density lipoproteins (VLDL) were fractionated by zonal ultracentrifugation, yielding sharply defined fractions with narrow sedimentation limits. Sedimentation coefficients for the individual fractions were determined at two densities with the analytical ultracentrifuge, and the results were analyzed to yield buoyant densities and molecular weights for the particles in each fraction. For the rat lipoproteins, the weight concentrations of triglycerides, cholesterol, phospholipid, and protein were determined for each fraction, and their molar concentrations of apolipoprotein B were measured with a radioimmunoassay. For the human lipoproteins the corresponding values were taken from Patsch et al. (Patsch, W., J. R. Patsch, G. M. Kostner, S. Sailer, and H. Braunsteiner. 1978. Isolation of subfractions of human very low density lipoproteins by zonal ultracentrifugation. J. Biol. Chem. 253:4911-4915). From these data, a ratio of the number of apoB peptides to the number of lipoprotein particles was calculated for each fraction. This ratio was close to 1 for all VLDL fractions, ranging in particle diameter from about 40 to 80 mm and 30 to 50 mm, respectively, for rat and human VLDL. The majority rat VLDL contain B-48 rather than B-100 as their (single) apoB peptide. Based on these data, we proposed that only a single copy of B-48 is required for VLDL assembly in rat liver, unless nascent hepatic VLDL contain additional apoB peptides which are uniformly lost from the plasma VLDL particles when they are analyzed.