The major isozyme of rat cardiac glutathione transferases. Its correspondence to hepatic transferase X.

1. A major isozyme of rat heart glutathione transferase was purified to homogeneity by Sephadex G-200 gel filtration, ammonium sulfate precipitation, CM-cellulose chromatography and affinity chromatography on S-hexylglutathione-linked Sepharose 6B. 2. The purified isozyme was a dimer with an apparent relative molecular mass of 50000 composed of two Yb-size subunits (Mr= 26 500). The isozyme is immunologically related to rat liver glutathione transferase X and 3–3, especially closely to transferase X, and no immunological cross-reactivity with subunits 1 and 2 of hepatic glutathione transferases was observed. The isoelectric point (pI = 6.9) of the isozyme was identical with and the substrat…