Stimulation of epoxide carboxylase activity by commercially obtained CoM. Assays were performed in duplicate in sealed 9-ml vials containing purified components (5 μg of component I, 250 μg of component II, 40 μg of component III, and 25 μg of component IV) in 50 mM Tris⋅HCl (pH 8.2). □, assays containing as-isolated component I; ○, assays containing component I preincubated with epoxypropane followed by gel filtration chromatography.