Isolation of gamma-glutamyl transpeptidase from human primary hepatoma and comparison of its kinetic and catalytic properties with the enzyme from normal adult and fetal liver.
gamma-Glutamyl transpeptidase (gamma-GT) from human primary hepatoma was solubilised and purified 290-fold with 25% recovery. The kinetic and catalytic properties were compared with those purified from human fetal and normal adult liver. Hepatoma gamma-GT did not differ from the fetal and adult liver gamma-GT in its pH optima for transpeptidation and auto-transfer reaction, heat stability, Km for the two substrates and inhibition by L-serine + borate. Enzyme from the three sources behaved in a similar manner towards various cations, sulphhydryl reagents, amino acid dipeptides. Adult liver enzyme showed a 4 time higher Ki value for anthglutin than hepatoma and fetal liver. The hepatoma gamma-GT could not be differentiated from that of adult and fetal liver by concanavalin-A Sepharose 4B column chromatography. The tissue concentration of gamma-GT was 3 to 13 times higher in hepatoma and fetal liver than in adult liver.
D000328:Adult; D000375:Aging; D006528:Carcinoma, Hepatocellular / Q000201:enzymology*; D004355:Drug Stability; D005260:Female; D005971:Glutamates / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008099:Liver / Q000196:embryology / Q000201:enzymology*; D008113:Liver Neoplasms / Q000201:enzymology*; D011247:Pregnancy; D005723:gamma-Glutamyltransferase / Q000302:isolation & purification / Q000378:metabolism*
D005971:Glutamates; D005723:gamma-Glutamyltransferase; C018830:anthglutin