Evidence that glutathione S-transferases B1B1 and B2B2 are the products of separate genes and that their expression in human liver is subject to inter-individual variation. Molecular relationships between the B1 and B2 subunits and other Alpha class glutathione S-transferases
- 1 December 1989
- journal article
- research article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 264 (2), 437-445
- https://doi.org/10.1042/bj2640437
Abstract
The Alpha class glutathione S-transferases (GSTs) in human liver are composed of polypeptides of Mr 25900. These enzymes are dimeric, and two immunochemically distinct subunits, B1 and B2, have been described that combine to form GSTs B1B1, B1B2 and B2B2 [Stockman, Beckett and Hayes (1985) Biochem. J. 227, 457-465]. Gradient affinity elution from GSH-Sepharose has been used to resolve the three Alpha class GSTs, and this method has been applied to demonstrate marked inter-individual differences in the hepatic content of GSTs B1B1, B1B2 and B2B2. The B1 and B2 subunits can be resolved by reverse-phase h.p.l.c., and their elution positions suggest that they are equivalent to the .alpha.x and .alpha.y h.p.l.c. peaks described by Ketterer and his colleagues [Ostlund Farrants, Meyer, Coles, Southan, Aitken, Johnson and Ketterer (1987) Biochem. J. 245, 423-428]. The B1 and B2 subunits have now been cleaved with CNBr and the fragments subjected to automated amino acid sequence analysis. The sequence data show that B1 and B2 subunits do not arise from post-translational modification, as had been previously believed for the hepatic Alpha class GSTs, but are instead the products of separate genes; B1 and B2 subunits were found to contain different amino acid residues at positions 88, 110, 111, 112, 116, 124 and 127. The relationship between the B1 and B2 subunits and the clones GTH1 and GTH2 cDNA sequences [Rhoads, Zarlengo and Tu (1987) Biochem. Biophs. Res. Commun. 145, 474-481] is discussed.This publication has 32 references indexed in Scilit:
- Electrophoretic and immunological analysis of human glutathione S‐transferase isozymesAnnals of Human Genetics, 1987
- The basic glutathione S-transferases from human livers are products of separate genesBiochemical and Biophysical Research Communications, 1987
- Subunit Heterogeneity of Cationic Human Hepatic Glutathione S-TransferasesPharmacology, 1987
- Human liver glutathione S-transferases: Complete primary sequence of an Ha subunit cDNABiochemical and Biophysical Research Communications, 1986
- Variations in the glutathione S-transferase subunits expressed in human liversBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1986
- Purification and subunit-structural and immunological characterization of five glutathione S-transferases in human liver, and the acidic form as a hepatic tumor markerBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1986
- The human glutathione S‐transferases: studies on the tissue distribution and genetic variation of the GST1, GST2 and GST3 isozymesAnnals of Human Genetics, 1984
- Structural and functional studies of ligandin, a major renal organic anion-binding protein.JCI Insight, 1975
- Ligandin: a Hepatic Protein which Binds Steroids, Bilirubin, Carcinogens and a Number of Exogenous Organic AnionsNature, 1971
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970