Takahara H, Matsuda K
J Biochem. 1977 Jun;81(6):1587-94. doi: 10.1093/oxfordjournals.jbchem.a131617.
A soluble enzyme preparation (20,000 X g supernatant fraction), prepared from the mycelia of wild-type Neurospora crassa, was capable of transferring [14C]glucose from UDP-[14C]glucose into both trichloroacetic acid (TCA)-soluble and TCA-insoluble macromolecule products in the absence of added primer. These reactions did not require either high concentrations of salts or any other chemical reagents. Two labeled products were formed; one was a glycogen-like polysaccharide and the other was a glycoprotein with glucosyl chains bound to protein through an acid-labile bond. After mild treatment of the glucoprotein with acid, the product liberated from the protein behaved as a mixture of malto-oligosaccharides and alpha-1,4-glucan with branches. The carbohydrate moiety of the glucoprotein seemed to be released upon prolonged incubation with the enzyme preparation. The glucan thus liberated from the glucoprotein may serve as a primer for the glycogen synthase. The results obtained are therefore suggestive of the existence of a glucoproteic intermediate in the initiation of glycogen biosynthesis.
从野生型粗糙脉孢菌的菌丝体制备的一种可溶性酶制剂（20,000×g 上清液组分），在没有添加引物的情况下，能够将 UDP-[14C]葡萄糖中的[14C]葡萄糖转移到三氯乙酸（TCA）可溶性和 TCA 不溶性大分子产物中。这些反应既不需要高浓度的盐，也不需要任何其他化学试剂。形成了两种标记产物；一种是类糖原多糖，另一种是糖蛋白，其糖基链通过酸不稳定键与蛋白质结合。用酸对糖蛋白进行温和处理后，从蛋白质中释放出的产物表现为麦芽寡糖和带有分支的α-1,4-葡聚糖的混合物。糖蛋白的碳水化合物部分在与酶制剂长时间孵育后似乎会被释放出来。由此从糖蛋白中释放出的葡聚糖可以作为糖原合酶的引物。因此，所获得的结果表明在糖原生物合成起始过程中存在糖蛋白中间体。
