Electrophoretic studies of serum gamma-glutamyl transferase from patients with hepatoma

Activities and isoenzyme patterns of gamma-glutamyl transferase (GGT) were studied in serum samples from fifteen Bantu males suffering from primary hepatoma; the results were compared with those obtained from normal samples. Enzyme activities were significantly higher in hepatoma patients than in controls. Results with Cellogel electrophoresis and the fluorescent substrate gamma-L-glutamine-7-amido-4-methylcoumarin were reproducible; two major bands of activity were observed in normal serum and three bands in hepatoma serum. The additional band seen in hepatoma serum was also detected in serum from patients with certain other disorders. With polyacrylamide gel electrophoresis using either gamma-L-glutamyl-alpha-naphthylamide or gamma-L-glutamyl-p-nitroanilide as substrates, results were inconsistent and difficult to interpret since there was a lack of specificity for GGT.