Hepatocyte specific long lasting inhibition of protein N-glycosylation by D-galactosamine.
Biochim Biophys Acta
; 1036(2): 143-50, 1990 Nov 09.
Article
en En
| MEDLINE
| ID: mdl-2121278
ABSTRACT
The effect of D-galactosamine on protein N-glycosylation was studied in rat hepatocyte primary cultures for alpha 1-antitrypsin (three complex type oligosaccharide chains) and alpha 1-acid glycoprotein (six complex type oligosaccharide chains). D-Galactosamine at a concentration of 4 mM inhibited partially de novo N-glycosylation leading to the formation of alpha 1-antitrypsin lacking one to two and of alpha 1-acid glycoprotein lacking one to five of its carbohydrate side chains. In addition D-galactosamine interfered with oligosaccharide processing, leading to the formation of some carbohydrate side chains remaining in an endoglucosaminidase H sensitive, i.e., not completely processed, form. D-Galactosamine impaired the secretion of alpha 1-antitrypsin and of alpha 1-acid glycoprotein but did not inhibit the secretion of the unglycosylated albumin. The inhibitory effect of D-galactosamine on de novo glycosylation as well as on oligosaccharide processing lasted for at least 24 h after it had been removed from the cells. D-Galactosamine impaired the glycosylation of alpha 1-antitrypsin only in hepatocytes, but not in human monocytes. Furthermore, D-galactosamine did not impair the N- and O-glycosylation of interleukin-6 in human monocytes and in MRC 5 fibroblasts. The results indicate that the effect of D-galactosamine on protein glycosylation is restricted to D-galactosamine metabolizing hepatocytes and is not exerted by the drug itself but by its metabolites.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Orosomucoide
/
Alfa 1-Antitripsina
/
Galactosamina
/
Hígado
Límite:
Animals
/
Female
/
Humans
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
1990
Tipo del documento:
Article