ALTERATION OF ASPARAGINE-LINKED GLYCOSYLATION IN SERUM TRANSFERRIN OFPATIENTS WITH HEPATOCELLULAR-CARCINOMA

The asparagine-linked sugar chains in serum transferrin purified from patients with hepatocellular carcinoma (n = 13). healthy individuals ( n = 5) and patients with liver cirrhosis (n = 6) were compared. Sugar chains released with N-glycanase from desialylated and pepsin-digested transferrin were derivatized by reductive pyridylamination, Analysis of the sugar chains by high performance liquid chromatography in combi nation with exoglycosidase digestion revealed an increase of a bianten nary complex-type sugar chain with a fucosylated trimannosyl core; bet a1-2Manalpha1-6(Galbeta1-4GlcNAcbeta1-2Mana1-3) Manbeta1-4GlcNAcbeta1- 4(Fucalpha1-6)GlcNAc in 7 of 13 cancer patients and an increase of a s ugar chain with a fucosylated trimannosyl core and bisecting N-acetylg lucosamine: Galbeta1-4GlcNAc-beta1-2Manalpha1-6(GlcNAcbeta1-4) eta1-2M analpha1-3)Manbeta1-4GlcNAcbeta1-4(Fucalpha 1-6)GlcNAc in one of the 1 3 cancer patients. Further, the fucosylated alteration of the sugar ch ain was detected also in alpha1-antitrypsin, hemopexin, alpha1-acid gl ycoprotein and alpha2-HS glycoprotein from one of the patients with in creased fucosylated transferrin.