Gogstad G, Helgeland L
Biochim Biophys Acta. 1978 Apr 20;508(3):551-64. doi: 10.1016/0005-2736(78)90099-8.
To study the transport of secretory glycoproteins in the endoplasmic reticulum of rat liver, the distribution of nascent glycoproteins in the membrane and luminal fraction of rough and smooth microsomes has been examined after a short-time incorporation of radioactive glucosamine in vivo. 50--60% of the radioactivity was associated with the membranes of rough and smooth microsomes, whereas about 10% of the serum albumin was found in the same fractions. The relative amount of radioactivity in the membranes was the same whether the luminal content of the microsomal vesicles was released by sonication, French press, Triton X-100, Brij 35 or sodium deoxycholate. The distribution of labeled glycoproteins between the membrane and luminal fraction of rough and smooth microsomes did not change during the time interval of 15--120 min after administration of the isotope. The similarity of the labeling patterns obtained after sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis indicated that the same set of glycoproteins were located in the lumen and the membrane of rough and smooth microsomes. A specific precipitation of nascent glycoproteins from both the membrane and luminal fractions of rough and smooth microsomes were obtained with rabbit antiserum against rat serum. The nascent glycoproteins associated with the membranes were not released by high ionic strength or treatment with mercaptoethanol. A slow exchange between [14C]glucosamine-labeled glycoproteins in the lumen and membrane fraction was, however, found.
为研究大鼠肝脏内质网中分泌性糖蛋白的转运，在体内短期掺入放射性葡糖胺后，检测了粗面和滑面微粒体膜及腔部分新生糖蛋白的分布。50% - 60%的放射性与粗面和滑面微粒体的膜相关，而在相同部分中发现约10%的血清白蛋白。无论通过超声处理、法国压榨机、Triton X - 100、Brij 35还是脱氧胆酸钠释放微粒体小泡的腔内容物，膜中放射性的相对量都是相同的。在给予同位素后的15 - 120分钟时间间隔内，粗面和滑面微粒体膜与腔部分之间标记糖蛋白的分布没有变化。十二烷基硫酸钠（SDS）-聚丙烯酰胺凝胶电泳后获得的标记模式相似，表明相同的一组糖蛋白位于粗面和滑面微粒体的腔和膜中。用抗大鼠血清的兔抗血清可从粗面和滑面微粒体的膜及腔部分特异性沉淀新生糖蛋白。与膜相关的新生糖蛋白不会因高离子强度或用巯基乙醇处理而释放。然而，发现腔和膜部分中[14C]葡糖胺标记的糖蛋白之间存在缓慢交换。
