Characterization of toad liver glutathione transferase

The major form of glutathione transferase from the toad liver previously de signed as Bufo bufo liver GST-7.6 (A. Aceto, B. Dragani, T. Bucciarelli, P. Sacchetta, F. Martini, S. Angelucci, F. Amicarelli, M. Miranda and C. Di I lio, Biochem. J. 289 (1993) 417-422) has been characterized. According to i ts partial amino acid sequence, the toad enzyme may be included in the pi c lass GST and named bbGST P2-2. However, bbGST P2-2 appears to be immunologi cally, structurally and kinetically distinct from any other members of pi f amily, including bbGST P1-1, suggesting that it may constitute a subset of pi class GST. The data support the hypothesis that the transition from aqua tic to terrestrial life causes a switch of the GST amphibian pattern promot ing the expression of a GST form (bbGST P2-2) able to counteract, with high er efficiency, the toxic effects of reactive metabolites of oxidative metab olism and those of hydrophobic xenobiotics. (C) 1999 Elsevier Science B.V. All rights reserved.