Smith M E, Sternberger N H
J Neurochem. 1982 Apr;38(4):1044-9. doi: 10.1111/j.1471-4159.1982.tb05346.x.
The effect of an inhibitor of N-glycosylation of glycoproteins, tunicamycin, on synthesis of PNS myelin proteins was investigated in vitro by using chopped sciatic nerves or spinal roots of 21-day-old Wistar rats. Tunicamycin when incubated with these nerves in the presence of 3H-labeled fucose, mannose, or glucosamine inhibited the uptake of radioactivity into myelin proteins including some high-molecular-weight proteins, P0, 23K protein, and 19K protein by amounts ranging from 42 to 79%. Uptake of 14C amino acid mixture was inhibited much less by tunicamycin, but a new radioactive protein peak appeared when the protein mixtures had been separated by electrophoresis on polyacrylamide gels in the presence of sodium dodecyl sulfate. This protein ran directly in front of the P0 peak, did not correspond to any bands stained by Fast green, and was not labeled by fucose. This peak appeared in increasing larger proportions with progressive time of incubation of nerves with 3H amino acids in the presence of tunicamycin. The new protein, which cross-reacts with P0 antiserum, was tentatively identified as a nonglycosylated P0 protein that appears to be almost as well incorporated as P0 into the subcellular fraction containing myelin. At this time it is not possible to determine whether the unglycosylated P0 is actually assembled into a site and configuration like that of P0.
通过使用21日龄Wistar大鼠的坐骨神经切段或脊神经根，在体外研究了糖蛋白N - 糖基化抑制剂衣霉素对周围神经髓鞘蛋白合成的影响。当衣霉素与这些神经在3H标记的岩藻糖、甘露糖或葡糖胺存在下孵育时，它对放射性掺入髓鞘蛋白（包括一些高分子量蛋白、P0、23K蛋白和19K蛋白）的抑制量在42%至79%之间。衣霉素对14C氨基酸混合物的摄取抑制作用要小得多，但当蛋白质混合物在十二烷基硫酸钠存在下通过聚丙烯酰胺凝胶电泳分离时，出现了一个新的放射性蛋白峰。该蛋白直接在P0峰之前迁移，与固绿染色的任何条带都不对应，并且未被岩藻糖标记。随着神经在衣霉素存在下与3H氨基酸孵育时间的延长，这个峰出现的比例越来越大。这种与P0抗血清发生交叉反应的新蛋白被初步鉴定为一种非糖基化的P0蛋白，它似乎几乎与P0一样好地掺入到含有髓鞘的亚细胞组分中。目前还无法确定未糖基化的P0是否真的组装成了与P0相同的位点和构型。
