Superactivity and phase-sensitivity of potato acid phosphatase entrapped in reverse micelles

Potato acid phosphatase, AcPase (E.C. 3.1.3.2) was entrapped in reverse micelles of cationic surfactant cetyltrimethylammonium bromide (CTAB) in isooctane and chloroform (1:1). The activity was studied at different values of Wo = ([water]/[surfactant]). AcPase exhibited superactivity in the reverse micellar system. At very low Wo value, activity was found to be less than that of in buffer and further increase in Wo value enhanced the activity thousand fold. At Wo = 50, the activity was enhanced more than twenty fold. The effect of second surfactant, TritonX-100, on superactivity was studied. There was a slight decrease in overall activity, when 3.33 mM TritonX-100 was added to the above reverse micellar system.