Characterization of a human class-Theta glutathione S-transferase with activity towards 1-menaphthyl sulphate.
A purification scheme is described for a glutathione S-transferase (GST) from human liver that catalyses the conjugation of 1-menaphthyl sulphate (MS) with GSH; the method devised results in an approx. 500-fold increase in specific activity towards MS. The human enzyme which metabolizes MS is a homodimer comprising subunits of M(r) 25,100, and immunochemical experiments have shown it to be a member of the class-Theta GSTs. Automated Edman degradation of this enzyme has confirmed that it is a Theta-class GST bu the amino acid sequence obtained differs from that of GST theta described previously [Meyer, Coles, Pemble, Gilmore, Fraser & Ketterer (1991) Biochem. J. 274, 409-414]. We have therefore designated the enzyme that catalyses the conjugation of MS with GSH GST T2-2* (in the absence of complete amino acid sequence data, the T1 and T2 subunits are provisionally designated T1* and T2*); the evidence which indicates that GST theta (which should possibly now be called GST T1-1*) and GST T2-2* represent distinct isoenzymes is discussed.
Hussey
A J
AJ
University Department of Clinical Biochemistry, Royal Infirmary, Edinburgh, Scotland, U.K.
Hayes
J D
JD
D000595:Amino Acid Sequence; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007120:Immunochemistry; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D009281:Naphthalenes / Q000378:metabolism*; D010449:Peptide Mapping; D012689:Sequence Homology, Nucleic Acid
D009281:Naphthalenes; D005982:Glutathione Transferase; C008348:1-menaphthyl sulfate