A PROTEIN INHIBITOR OF HEPATIC DRUG-METABOLIZING-ENZYMES FROM EHRLICHASCITES-CELLS

Hepatic drug metabolizing enzymes were significantly decreased in Ehrl ich ascites tumour-bearing mice. A protein inhibitor of hepatic drug m etabolizing enzymes was isolated from Ehrlich ascites cells and purifi ed. This involved ammonium sulphate fractionation (60-80%), DEAE, phos phocellulose, Sephadex G-100 and hydroxyapatite column chromatography. Purification attained was 800-fold. The inhibitory protein was effect ive in decreasing all the components of hepatic mixed-function-oxidase system and drug metabolizing enzymes both in vivo and in vitro. This novel inhibitor may have potential applications in chemical carcinogen esis. (C) 1997 Elsevier Science Ireland Ltd.