Sun G Y, Huang H M, Kelleher J A, Stubbs E B, Sun A Y
Sinclair Comparative Medicine Research Farm and Department of Biochemistry, University of Missouri, Columbia, MO 65203, U.S.A.
Neurochem Int. 1988;12(1):69-77. doi: 10.1016/0197-0186(88)90150-7.
Subjecting brain homogenates to differential speed and sucrose density gradient centrifugation resulted in the isolation of a membrane fraction from the post-mitochondrial supernatant with properties and marker enzyme profiles typical of plasma membranes. This membrane fraction is compared with the microsomes and the synaptic plasma membranes isolated from synaptosomes. Like the synaptic plasma membranes, membranes obtained from the post-mitochondrial supernatant were enriched five-fold in 5?-nucleotidase activity. However, the latter membranes were lower in (Na(+), K(+))-ATPase activity and higher in NADPH-cytochrome C reductase activity as compared to the synaptic plasma membranes. The post-mitochondrial plasma membranes were also different from the microsomes in their respective marker enzyme activities. Electron microscopic examination indicated largely membranous vesicles for both plasma membrane fractions with little contamination by myelin, mitochondra and intact synaptosomes. The phospholipid and acyl group profiles of the two plasma membrane fractions were surprisingly similar, but they were different from the characteristic profiles of myelin and mitochondria. It is concluded that plasma membranes isolated from the post-mitochondrial supernatant fraction are derived largely from neuronal and glial soma and are thus designated the somal plasma membrane fraction.
将脑匀浆进行差速离心和蔗糖密度梯度离心，从线粒体后上清液中分离出一种膜组分，其具有质膜典型的特性和标志酶谱。将该膜组分与从突触体中分离出的微粒体和突触质膜进行比较。与突触质膜一样，从线粒体后上清液中获得的膜在5'-核苷酸酶活性方面富集了五倍。然而，与突触质膜相比，后者的膜在（钠，钾）-ATP酶活性方面较低，而在NADPH-细胞色素C还原酶活性方面较高。线粒体后质膜在各自的标志酶活性方面也与微粒体不同。电子显微镜检查表明，两种质膜组分主要是膜性囊泡，几乎没有髓磷脂、线粒体和完整突触体的污染。两种质膜组分的磷脂和酰基谱惊人地相似，但与髓磷脂和线粒体的特征谱不同。得出的结论是，从线粒体后上清液组分中分离出的质膜主要来源于神经元和神经胶质细胞体，因此被称为体细胞质膜组分。
