Glycosylation of human leukocyte interferon: effects of tunicamycin.
Antiviral activity of interferon secreted by human leukocytes into the culture fluid in the presence of tunicamycin (1-2 microgram/ml) was significantly decreased, by 50-60 percent, in comparison to that produced in the absence of the antibiotic. No loss in antiviral activity occurred when tunicamycin was added to already harvested interferon preparations. Some physico-chemical and biological properties of human leukocyte interferon synthesized in the presence of tunicamycin (HL-IFT) were apparently altered by comparison with those of control preparations of human leukocyte interferon (HL-IF): HF-IFT had only one molecular weight component of 16,000 daltons in contrast to the two components of HL-IF of 16,000 and 21,000 daltons. HL-IFT also had a higher apparent hydrophobicity and was less efficiently neutralized by an antibody raised against HL-IF. However, some other properties remained unchanged: isoelectric point, pI about 6; affinity for immobilized polyriboinosinic acid and a spectrum of cross-species antiviral activity. These data support the notion that the major component of HL-IF (70%, 16,000 daltons) is apparently nonglycosylated whereas the minor component (30%, 21,000 daltons) is glycosylated via saccharide-lipid intermediates.
D000941:Antigens; D055598:Chemical Phenomena; D002621:Chemistry; D003847:Deoxyglucose / Q000494:pharmacology; D005944:Glucosamine / Q000031:analogs & derivatives*; D006801:Humans; D007372:Interferons / Q000032:analysis / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D007526:Isoelectric Point; D008970:Molecular Weight; D011069:Poly I / Q000378:metabolism; D012685:Sepharose; D014415:Tunicamycin / Q000494:pharmacology*
D000941:Antigens; D014415:Tunicamycin; D011069:Poly I; D007372:Interferons; D012685:Sepharose; D003847:Deoxyglucose; D005944:Glucosamine