Effect of purified rat and hamster hepatic glutathione S-transferases on the microsome mediated binding of aflatoxin B1 to DNA.
Rat and hamster liver cytosolic glutathione (GSH) S-transferases purified by GSH-affinity chromatography have been examined for their effects on the microsome mediated binding of aflatoxin B1 (AFB1) to DNA and on the conjugation of AFB1-2,3-epoxide with GSH. Like previous studies with cytosolic preparations (Raj et al. (1984) Carcinogenesis 5, 879), our present study with purified GSH S-transferases showed 2-3-fold more inhibitory activity of AFB1-DNA binding with hamster than that with the rat. Concomitant with the inhibition of AFB1-DNA binding, increase in AFB1-GSH conjugation occurred. Subunit compositions of GSH S-transferases indicate preponderance of Yb and Ya subunits in the hamster and rat, respectively. The role of GSH S-transferases in modulating AFB1-DNA binding and AFB1 induced hepatocarcinogenesis is discussed.
D016604:Aflatoxin B1; D000348:Aflatoxins / Q000378:metabolism*; D000818:Animals; D001711:Biotransformation; D006224:Cricetinae; D003600:Cytosol / Q000201:enzymology; D004247:DNA / Q000378:metabolism*; D004852:Epoxy Compounds; D005978:Glutathione / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism*; D051381:Rats
D000348:Aflatoxins; D004852:Epoxy Compounds; D004247:DNA; D016604:Aflatoxin B1; D005982:Glutathione Transferase; D005978:Glutathione