The effects of ionic and non-ionic detergents on Escerichia coli ?-galactosidase activity

The effects of several ionic and non-ionic detergents on ?-Galactosidase activity at 30°C have been evaluated. The detergent concentrations tested were in the ranges that are already used in most assays to permeablise and reveal proteins from most tissues. The results obtained indicate that the anionic detergent SDS at all concentrations inhibited ?-Galactosidase activity, whereas non-ionic detergents, Triton-X 100 and Tween 20 have no effects on the enzyme activity. The electrophoretic analysis of SDS-exposed enzyme shows two bands corresponding to 170 kD and 116 kD, only the former being active.