Purification and Characterization of Acidic Form of Glutathione S-Transferase in Human Fetal Livers: High Similarity to Placental Form

An acidic form of glutathione S-transferase (GST) was purified from human fetal livers by means of affinity chromatography and chromatofocusing. The major peak of the acidic form of GST was focused between pH 4.8 and 4.9. Judging by SDS-PAGE, the purified acidic GST was apparently homogeneous; the subunit molecular weight was estimated to be 23,000. The acidic GST catalyzed the conjugations of glutathione (GSH) with l-chloro-2,4-dinitro-benzene (CDNB) and ethacrynic acid (EA). The immunochemical properties of the purified acidic GST were indistinguishable from those of human placental GST-π. The N-terminal amino acid sequence of the acidic GST was identical with that of GST-π from human placenta. The level of expression of the acidic form of GST was clearly different between human adult and fetal livers as examined on the levels of mRNA and protein.