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Glycoprotein Biosynthesis in Peripheral Nervous System Myelin: Effect of Tunicamycin
Author(s) -
Smith Marion Edmonds,
Sternberger Nancy H.
Publication year - 1982
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1982.tb05346.x
Subject(s) - tunicamycin , glycoprotein , myelin , biosynthesis , peripheral nervous system , nervous system , peripheral , central nervous system , microbiology and biotechnology , neuroscience , biology , chemistry , biochemistry , medicine , endoplasmic reticulum , enzyme , unfolded protein response
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 3 H‐labeled fucose, mannose, or glucosamine inhibited the uptake of radioactivity into myelin proteins including some high‐molecular‐weight proteins, P 0 , 23K protein, and 19K protein by amounts ranging from 42 to 79%. Uptake of 14 Camino 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 P 0 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 3 H amino acids in the presence of tunicamycin. The new protein, which cross‐reacts with P 0 antiserum, was tentatively identified as a nonglycosylated P 0 protein that appears to be almost as well incorporated as P 0 into the subcellular fraction containing myelin. At this time it is not possible to determine whether the unglycosylated P 0 is actually assembled into a site and configuration like that of P 0 .