Comparative study of the sugar chains of gamma-glutamyltranspeptidases purified from human hepatocellular carcinoma and from human liver.

The sugar chains of gamma-glutamyltranspeptidases, purified from human hepatoma and from normal human liver, were released quantitatively as oligosaccharides by hydrazinolysis. Comparative study of their structures revealed that the following structural alterations are induced by hepatocyte carcinogenesis: 1) high mannose type sugar chains are detected in the hepatoma enzyme but not in the normal liver enzyme; 2) abnormal biantennary sugar chains containing C-2,4 outer chain branches newly appeared; 3) the total amounts of tri- and tetraantennary sugar chains containing C-2,6 outer chain branches increased up to three times.