Catabolic properties of aglycofibrinogen synthesized by tunicamycin-treated human hepatoma (HepG2) cells and rabbit hepatocytes.
Human hepatoma cell (HepG2) or rabbit hepatocyte monolayers were incubated with [35S]methionine in presence or absence of tunicamycin, a potent inhibitor of asparagine-linked glycosylation. The 35S-labeled nonglycosylated and control fibrinogens purified from the media were used to evaluate the influence of the oligosaccharide on the catabolic properties of this glycoprotein. Plasmin, pronase, cathepsin D or cathepsin B each degraded the nonglycosylated and control fibrinogens similarly, as evidenced by the release of trichloroacetic acid-soluble radioactivity and by SDS-polyacrylamide gel electrophoresis and autoradiography of plasmic digests. Nonglycosylated and control fibrin clots also showed no differences in susceptibility to plasmic digestion. The two forms of fibrinogen demonstrated the same plasma half-life in rabbits. These data indicate that the oligosaccharide does not influence the proteolytic stability or the in vivo plasma survival of fibrinogen, and suggest that other biochemical determinants may influence the catabolic properties of this molecule.
D000818:Animals; D001777:Blood Coagulation; D006528:Carcinoma, Hepatocellular / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D008099:Liver / Q000378:metabolism*; D008113:Liver Neoplasms; D008715:Methionine / Q000378:metabolism; D009844:Oligosaccharides / Q000502:physiology; D011817:Rabbits; D014415:Tunicamycin / Q000494:pharmacology*
D009844:Oligosaccharides; D014415:Tunicamycin; D005340:Fibrinogen; D008715:Methionine