Purification and characterization of P-52 (glutathione S-transferase-P or 7-7) from normal liver and putative preneoplastic liver nodules

Cancer Res. 1988 May 15;48(10):2805-12.

Abstract

A previous study from our laboratory (L.C. Eriksson et al., Biochem. Biophys. Res. Commun., 117: 740-745, 1983) revealed that a cytosolic polypeptide of approximate Mr 21,000 (designated P-21) was markedly elevated in amount in hepatocyte nodules induced by six different regimens. The molecular weight of this polypeptide, subsequently revised to approximately 26,000, was redesignated P-26 and was identified (T.H. Rushmore et al., Biochem. Biophys. Res. Commun., 143: 98-103, 1987) as a subunit of a placental form of glutathione S-transferase (K. Sato et al., Gann 75: 199-202, 1984), also named glutathione S-transferase 7-7 (H. Jensson et al., FEBS Lett., 187: 115-120, 1985). We describe here a convenient method for purifying relatively large amounts of P-26 from hepatocyte nodules involving the sequential use of affinity chromatography on S-hexyl glutathione-Sepharose 4B, CM-Sephadex, and DEAE-Sephacel. Evidence is presented that P-26 exists as a dimer of approximate Mr 52,000 (P-52). Analyses by two-dimensional electrophoresis have indicated that the subunits of Mr 26,000 may consist of five separate charged isomers. Investigations using appropriate antisera and analysis by amino acid sequencing have provided additional confirmation that P-52 is probably identical to rat placental glutathione S-transferase. Antibodies to P-52 are proving to be useful as a marker of new cell populations that appear regularly during hepatocarcinogenesis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chromatography, High Pressure Liquid
  • Electrophoresis, Polyacrylamide Gel
  • Glutathione Transferase / analysis
  • Glutathione Transferase / immunology
  • Glutathione Transferase / isolation & purification*
  • Liver / enzymology*
  • Liver Neoplasms, Experimental / enzymology*
  • Male
  • Molecular Sequence Data
  • Molecular Weight
  • Placenta / enzymology
  • Precancerous Conditions / enzymology*
  • Rats

Substances

  • Glutathione Transferase