Glutathione S-transferases from rainbow trout liver and freshly isolated hepatocytes: purification and characterization

Glutathione S-transferases (GST) form an important family of biotransformat ion enzymes catalyzing the conjugation of glutathione to a great variety of xenobiotic compounds. The objective of this study was to compare the diffe rent characteristics of GST from freshly isolated rainbow trout hepatocytes with those corresponding to the total liver of the same fish, in order to establish the similarities. GST was purified by affinity chromatography and enzymatic activity was determined towards two substrates, 1-chloro-2,4-din itrobenzene (CDNB) and ethacrynic acid (ETHA). The different isoenzymes wer e determined by HPLC associated with SDS-PAGE. Slight differences between t he samples were obtained when the results corresponding to the enzyme activ ity were compared. HPLC results showed that all GST isoforms present in the total liver samples were represented in the isolated cells too, correspond ing to isoforms with molecular masses of approximately 25.5 and 23.0 kDa. ( C) 2001 EIsevier Science Inc. All rights reserved.