Purification and properties of the hepatic glutathione S-transferases of the Atlantic salmon (Salmo salar).

Salmon from salt water have three classes of soluble hepatic glutathione S-transferases which can be separated from cytosol by affinity chromatography and chromatofocusing. The classes have different substrate specificities and kinetic properties. All the enzymes are dimeric proteins. There are immunologically distinct subunits of Mrs 22.4, 23.0 and 24.0 kDa. Fish killed in August have enzymes with different apparent isoelectric points and subunit compositions than fish killed in February. The glutathione S-transferase activity of fresh-water salmon is similar to that of February salt-water fish except that the former binds less avidly to S-hexylglutathione-Sepharose 6B.