Isoenzymes of glutathione transferase in rat kidney cytosol

Abstract

Glutathione transferases from rat kidney cytosol were purified about 40-fold by chromatography on S-hexylglutathione linked to epoxy-activated Sepharose 6B. Further purification by fast protein liquid chromatography with chromatofocusing in the pH interval 10.6-7.6 resolved five major peaks of activity with 1-chloro-2,4-dinitrobenzene as the second substrate. Four of the peaks were identified with rat liver transferases 1-1, 1-2, 2-2 and 4-4 respectively. The criteria used for identification included physical properties, reactions with specific antibodies, substrate specificities and sensitivities to several inhibitors. The fourth major peak is a 'new' form of transferase, which has not been found in rat liver. This isoenzyme, glutathione transferase 7-7, has a lower apparent subunit Mr than any of the transferases isolated from rat liver cytosol, and does not react with antibodies raised against the liver enzymes. Glutathione transferases 3-3 and 3-4, which are abundant in liver, were only present in very small amounts. In a separate chromatofocusing separation in a lower pH interval, an additional peak was eluted at pH 6.3. This isoenzyme is characterized by its high activity with ethacrynic acid.

Sex Differences in the Subunits of Glutathione-S-Transferase Isoenzyme from Rat and Human Kidney

“…while the acidic forms of human GSTs show specificity for ethacrynic acid [12,13]. This specificity resembles that observed by Guthenberg et al [ 14] for an acidic transferase isolated from rat kidney. Antibodies raised against an isoenzyme of one group do not cross-react with enzymes of other groups bands at 25.3, 22 and 29 kD did not react with any of these antibodies.…”

Purification and properties of glutathione transferase from Issatchenkia orientalis

“…Especially in mammals, many tissue-specific (11,12,16) and species-specific (2,3,9,20) GST isoenzymes have been purified, and their properties and functions in cells have been studied extensively. GST activities have also been found in plants (10) and insects (8), and they are related to resistance to herbicides and insecticides.…”

Selective expression of glutathione transferase isoenzymes in chemically induced preneoplastic rat heptocyte nodules

“…The most characteristic properties of this isoenzyme are low apparent subunit M,, relatively high activity with ethacrynic acid, and a positive precipitin reaction with antibodies raised against human placenta1 transferase r. An isoenzyme which by all available criteria appears identical with the non-typical hepatic glutathione transferase in the nodules has been purified from lung, kidney and placenta [ 18,19,23]. This enzyme has been named rat glutathione transferase 7-7 [ 181 or transferase P (241.…”

“…It was recently found in our laboratory (C. Guthenberg et al, unpublished) that antibodies raised against human glutathione transferase 7r from placenta cross-react with rat glutathione transferase 7-7 isolated from rat kidney or lung [ 18,191. By using these antibodies, significant levels of immunoprecipitable material in the nodule cytosol fraction were demonstrated, whereas normal liver did not contain detectable amounts.…”