Bovine erythrocyte glutathione S-transferase: purification, inhibition, and complex formation.
Glutathione S-transferase has been purified from bovine erythrocytes by affinity chromatography. The enzyme has an isoelectric point of 7.2, behaves as a 48-kDa protein composed of two identical subunits, and has an N-terminal sequence of PPYTIVYFPVQGR?EAMRMLL. This sequence, the amino acid composition, and the kinetic parameters suggest that the enzyme belongs to the pi-class of transferases. Hemins, porphyrins, and fatty acids form complexes with the enzyme and serve as effective inhibitors. Treatment of the transferase with N-ethylmaleimide, 3-amino-1,2,4-triazole, diethyl pyrocarbonate, or 2,3-butanedione inhibits transferase activity without altering tetrapyrrole binding. The role of the complexation and inhibition of glutathione S-transferase in erythroid metabolism has yet to be elucidated.
Xu
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Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-0606.
Hultquist
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D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004912:Erythrocytes / Q000201:enzymology*; D005227:Fatty Acids / Q000378:metabolism; D005982:Glutathione Transferase / Q000037:antagonists & inhibitors / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification*; D006427:Hemin / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D011166:Porphyrins / Q000378:metabolism; D011485:Protein Binding
D005227:Fatty Acids; D011166:Porphyrins; D006427:Hemin; D005982:Glutathione Transferase