Use of Tetraethylthiuram Disulfide to Discriminate between Alternative Respiration and Lipoxygenase

Abstract
Mitochondria from axes of Glycine max (L.) Merr. cv. Chippewa 64 seedlings purified on discontinuous Percoll gradients exhibited classical cyanide-resistant respiration. These mitochondria possessed lipoxygenase activity, as determined by O2 uptake in the presence of 0.8 mM linoleic acid. This activity is inhibited by most known inhibitors of alternative respiration (i.e., hydroxamates and propyl gallate). Tetraethylthiuram disulfide (disulfiram) at 50 .mu.M inhibited cyanide-resistant succinate oxidation by 90%; concentrations as high as 100 .mu.M had no effect on lipoxygenase activity. Use of tetraethylthiuram disulfide allows discrimination between alternative respiration and lipoxygenase activity in mitochondria.