title: Glutathione conjugation of microsome-mediated and synthetic aflatoxin B1-8,9-oxide by purified glutathione S-transferases from rats.
abstract: Glutathione (GSH) conjugation of microsome-mediated and synthetic aflatoxin B1 (AFB1)-epoxide and styrene oxide has been investigated with purified GSH S-transferases (GSTs) from rats. Both styrene oxide and AFB1-epoxide were conjugated preferentially by millimicrons GSTs 3-3, 3-4 and 4-4 as compared to alpha GSTs 1-1, 1-2 and 2-2. The highest catalytic activity with styrene oxide conjugation was associated with GST 4-4. The highest catalytic activity with microsome-mediated AFB1-epoxide conjugation was observed with GST 3-3 whereas with the synthetic AFB1-epoxide conjugation was seen with GST 4-4. The catalytic activity of pi GST 7-7 was intermediate to millimicrons and alpha GSTs. It is suggested that GST 3-3 may play an important role in inactivation of AFB1-epoxide generated in vivo in the rat.
authors.affiliation: Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA.
authors.forename: P
authors.initials: P
authors.lastname: Gopalan
authors.forename: D E
authors.initials: DE
authors.lastname: Jensen
authors.forename: P D
authors.initials: PD
authors.lastname: Lotlikar
mesh_terms: D016604:Aflatoxin B1 / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D003600:Cytosol / Q000201:enzymology; D004852:Epoxy Compounds / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D005982:Glutathione Transferase / Q000302:isolation & purification / Q000378:metabolism*; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D004852:Epoxy Compounds; D007527:Isoenzymes; C006426:aflatoxin B1-2,3-oxide; D016604:Aflatoxin B1; C013690:styrene oxide; D005982:Glutathione Transferase; D005978:Glutathione