Transformation of leukotriene A4 methyl ester to leukotriene C4 monomethyl ester by cytosolic rat glutathione transferases

Abstract

Six major basic cytosolic glutathione transferases from rat liver catalyzed the conversion of leukotriene A₄ methyl ester to the corresponding leukotriene C₄ monomethyl ester. Glutathione transferasc 4‐4, the most active among these enzymes, had a V _maxof 615 nmol · min⁻¹ · mg protein⁻¹ at 30°C in the presence of 5 mM glutathione. It was followed in efficiency by transferase 3–4 which had a V _max of 160 nmol · min⁻¹ · mg⁻¹ under the same conditions. Transferases 1‐1, 1‐2, 2‐2 and 3‐3 had at least 30 times lower V _max values than transferase 4‐4.