Purification and properties of hamster liver ligandins, glutathione S-transferases.

Glutathione S-transferases have been purified to homogeneity from Chinese hamster liver. Three enzyme forms were separated and designated Forms I, II, and III in order of their elution from carboxymethylcellulose columns. The forms exhibit close physical similarities to glutathione S-transferases B (ligandin) of rat liver and epsilon of humam liver. However, enzyme kinetic analysis indicates that the hamster enzymes exhibit similar Km values but higher Vmax values towards common substrates compared with the rat and human forms. These differences, which explain the increased enzymic activities of hamster glutathione S-transferases in vivo and in vitro, appear to be related to slight differences in the peptide composition of hamster liver glutathione S-transferases compared to the rat and human enzymes.