Effect of Sodium Dodecyl Sulfate on D -Glucose-isomerizing Enzyme from Bacillus coagulans , Strain HN-68

Crystalline D-glucose-isomerizing enzyme from Bacillus coagulans, strain NH–68 has been shown to consist of subunits by the method of electrophoresis on sodium dodecyl sulfate (SDS) polyacrylamide gels. The dissociation behavior of the enzyme has been characterized. The enzyme dissociates into inactive subunits by the preincubation with 0.05% SDS in the presence of 5 × 10−3M MnCl2 or CoCl2, but not in the absence of these metal salts. In 8 м urea, however, the enzyme does not dissociate into subunits and the activity is completely recovered by dilution of the urea. Metal salts, such as MnCl2 and CoCl2, also do not affect activity in the presence of urea.