Pless D D, Lennarz W J
J Biol Chem. 1975 Sep 10;250(17):7014-9.
Endogenous proteins of cell-free preparations of hen oviduct labeled from GDP-[14C]Man or from [Man-14C]oligosaccharide-lipid have been compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Under the conditions tested, a polypeptide chain of molecular weight about 25,000 was the principle acceptor for the oligosaccharide moiety of exogenous [Man-14C]oligosaccharide-lipid. The product labeled by [Man-14C]oligosaccharide-lipid appeared identical with one of three glycoproteins formed when GDP-[14C]Man was incubated with a crude membrane fraction. These three proteins (apparent molecular weight of 75,000, 55,000, and 25,000) accounted for nearly two-thirds of the [14C]mannose-labeled glycoprotein products using GDP-[14C]Man and either the crude membrane fraction or a total oviduct homogenate. Thus, all of the mannose acceptor proteins present in the oviduct homogenate appear to be membrane-bound. Analyses of the [Man-14C]glycoproteins labeled from GDP-[14C]Man in membrane fractions from hen kidney, liver, brain, and oviduct indicated that a labeled polypeptide of apparent molecular weight 25,000 was the only major protein product common to the four preparations.
通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳，对从GDP-[14C]甘露糖或[甘露糖-14C]寡糖脂标记的母鸡输卵管无细胞制剂中的内源性蛋白质进行了比较。在所测试的条件下，分子量约为25,000的多肽链是外源性[甘露糖-14C]寡糖脂寡糖部分的主要受体。用[甘露糖-14C]寡糖脂标记的产物与GDP-[14C]甘露糖与粗膜部分孵育时形成的三种糖蛋白之一相同。这三种蛋白质（表观分子量分别为75,000、55,000和25,000）占使用GDP-[14C]甘露糖以及粗膜部分或整个输卵管匀浆的[14C]甘露糖标记糖蛋白产物的近三分之二。因此，输卵管匀浆中存在的所有甘露糖受体蛋白似乎都是膜结合的。对来自母鸡肾脏、肝脏、大脑和输卵管的膜部分中从GDP-[14C]甘露糖标记的[甘露糖-14C]糖蛋白的分析表明，表观分子量为25,000的标记多肽是这四种制剂共有的唯一主要蛋白质产物。
