Nishinaka T, Yasunari C, Abe A, Nanjo H, Terada T, Nishihara T, Mizoguchi T
Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Osaka University, Japan.
Curr Eye Res. 1993 Apr;12(4):333-40. doi: 10.3109/02713689308999457.
Two glutathione S-transferase (GST) isozymes, GST-rl1 and GST-rl2, were purified from rabbit lenses and their properties were compared with those of other animals. GST-rl1 and GST-rl2 are dimeric enzymes whose subunit sizes are 24,000 and 21,500, respectively. The substrate specificities and inhibitor sensitivities of GST-rl1 and GST-rl2 are different from each other and from those of the isozymes from other animals. GST-rl1 immunologically crossreacted with the antibody against class mu GST (rat GST Yb1-Yb1), and GST-rl2 crossreacted with the antibody against class pi GST (rat GST Yp-Yp). N-Terminal amino acid sequences of GST-rl1 and GST-rl2 have great homology with other class mu and class pi enzymes, and thus indicate that they belong to class mu and class pi, respectively. Class pi GST-rl2 is inactivated by 1,2-naphthoquinone, an oxidized metabolite of naphthalene, but class mu GST-rl1 is insensitive to it. These results are similar to those of class pi pig lens GST and class mu bovine lens GST. Thus, the expression pattern of GST isozymes in lens varies with animal species, and may relate to their variation in sensitivity to oxidative stress.
