Characterization of two mu class glutathione S-transferases from guinea pig lens

Glutathione S-transferase (GST) plays an important role in the detoxifications of foreign electrophiles. Two GSTs of class mu from guinea pig lens were purified with Sephacryl S-100 gelfiltration, S-Hexyl glutathione Agarose affinity and Q-Sepharose anion exchange chromatographies. These GSTs (GST-A and B) showed similar relative molecular masses of 22.9 and 22.5 kDa, respectively. Two protein bands which crossreacted with anti GSTYb1 (GST 3-3) were detected in lens cytosolic crude extract on Western blotting and they showed Mrs corresponding to the purified enzymes. These GSTs showed a strong resistance against H2O2, 1,2-naphthoquinone and superoxide anion consistent with the other GSTs in class mu from animal tissues.