Mouse kidney trehalase: purification and properties

Abstract

Trehalase (E.C.3.2.1.28) was isolated from mouse kidney and purified to homogeneity. The enzyme was solubilized with n-octanol and activated by freezing and thawing before precipitation with ammonium sulfate. A 1700-fold purification was achieved by chromatography on DEAE-cellulose, SP-Sephadex, followed by gel filtration on Sephadex G-200. Only a single form of enzyme activity was shown throughout the fractionation as confirmed by gel electrophoresis of the final preparation. The enzyme was specific for trehalose and its estimated molecular weight by filtration on Sephadex G-200 was 73,000. The Km for trehalose was shown to be 2.67 x 10(-3)M and the optimum pH was in the range of 5.5-5.6. We have also shown that the optimum temperature of the enzyme is 60 degrees C, but in the absence of substrate, thermal inactivation occurred at 55 degrees C.