Studies on the relationship of hepatic anion-binding proteins and sulfobromophthalein-glutathione conjugation in normal and phenobarbital-treated rats

The enzyme activity which conjugates sulfobromophthalein with glutathione was separated from rat liver supernate by Sephadex G-75 gel filtration, and assayed by two different methods; paper electrophoresis and spectrophotometry. The enzyme activity was found mainly in the second protein fraction, and less than 5% of the activity in the first or third protein fractions. In vitro mixtures of sulfobromophthalein, ³H]glutathione and rat liver supernate showed that the major part of ³H]glutathione was detected in the first and second protein fractions, and the remainder in the third protein fraction. Phenobarbital treatment caused an increase of the enzyme activity, sulfobromophthalein and ³H]glutathione, in the second protein fraction.