Rubenstein B, Rubinstein D
J Lipid Res. 1972 May;13(3):317-24.
An exchange of phospholipids and certain peptides among various classes of rat serum lipoproteins has been demonstrated and its nature has been investigated. [(32)P]-Phospholipid from isolated VLDL, prepared in vivo, was transferred to HDL, and to a much lesser extent to LDL, in vivo and in vitro. This difference between HDL and LDL can be abolished by ultracentrifugation of the serum at d 1.21. Unlabeled VLDL acquired [(32)P]phospholipid from HDL of serum. Phospholipid associated with the alpha-lipoprotein component of VLDL exchanged more readily than that associated with the beta-lipoprotein component of VLDL. Generally, the phospholipid species exchange in proportion to their distribution in the lipoproteins. Radioactivity from (3)H-labeled protein of VLDL was transferred to HDL while HDL (3)H-labeled protein in serum was transferred to VLDL during a 20-min incubation. LDL was not involved in the transfer of protein. Protein associated with the alpha-lipoprotein component of VLDL exchanged more readily than that associated with beta-lipoprotein component. Analysis of tritiated apoproteins of VLDL and HDL by polyacrylamide gel electrophoresis revealed that three of the six peptide bands of apo-VLDL exchanged between VLDL and HDL. The data raise the possibility that intact subunits of the VLDL and HDL are being exchanged.
已证实大鼠血清各类脂蛋白之间存在磷脂和某些肽的交换，并对其性质进行了研究。体内制备的分离极低密度脂蛋白（VLDL）中的[（32）P]磷脂，在体内和体外都转移到了高密度脂蛋白（HDL），并在较小程度上转移到了低密度脂蛋白（LDL）。血清在密度1.21下超速离心可消除HDL和LDL之间的这种差异。未标记的VLDL从血清HDL中获得了[（32）P]磷脂。与VLDL的α脂蛋白成分相关的磷脂比与VLDL的β脂蛋白成分相关的磷脂更容易交换。一般来说，磷脂种类的交换与其在脂蛋白中的分布成比例。在20分钟的孵育过程中，VLDL的（3）H标记蛋白的放射性转移到了HDL，而血清中HDL的（3）H标记蛋白转移到了VLDL。LDL不参与蛋白质的转移。与VLDL的α脂蛋白成分相关的蛋白质比与β脂蛋白成分相关的蛋白质更容易交换。通过聚丙烯酰胺凝胶电泳对VLDL和HDL的氚标记载脂蛋白进行分析，发现apo-VLDL的六个肽带中的三个在VLDL和HDL之间发生了交换。这些数据增加了VLDL和HDL完整亚基正在交换的可能性。
