Studies on beta-galactosidase from Candida pseudotropicalis III- Purification and some properties of the pure enzyme

ABSTRACT

Beta-galactosidase from Candida pseudotropicalis was partially purified by fractional precipitation with ammonium sulfate. Purification was achieved by sephadex G-75 and the cellulose DE-52 column chromatography, the purification fold was 5.2, 20.6 and 104.2, respectively. The purity of enzyme was checked on polyacrylamide gel Disc electrophoresis. The properties of the purified enzyme have been studied. The Km and V max were 4 x 10-5 M and 27 x 106 M/min-1, respectively. The maximum enzyme activity was obtained in 0.2 M potassium phosphate buffer at pH 7.0 and incubation temperature 30C for 25 minutes. The effect of temperature, pH on enzyme stability and activity was studied. The enzyme was strongly activated by Mg+2, while as Mn+2, Ca+2, Na+2 and Zn+2 had an activating effect at low concentrations and Cu+2 showed complete inhibition