Purification and characterization of beta-galactosidase from rat epididymal fluid.

ABSTRACT

Beta-galactosidase from rat epididymal fluid was purified by a combination of chromatographic techniques and precipitation with ammonium sulphate. Specific activity of the enzyme in the final precipitate was 18 times greater than in the original fluid, and it was practically free of N-acetyl-beta-D-glucosaminidase. A single major band was seen when the precipitate was analysed by sodium dodecylsulphate polyacrylamide gelectrophoresis (SDS-PAGE). The activity of the purified enzyme has an optimum at pH 4.5, and the temperature optimum is around 45 degrees C. The activity was inhibited by p-chloromercuribenzoic acid and ions such as Cd(II), Co(II), Cu(II) and Ag(I). Lactose does not appear to be a substrate for this enzyme.