| Popis: |
Trehalose-hydrolyzing enzymes from particulate and cytosolic components of the thoracic musculature of Periplaneta americana were isolated and purified to homogeneity. The molecular weights of the respective enzymes were determined by SDS-polyacrylamide gel electrophoresis and Sephadex G-150 column chromatography and estimated to be 80,000 Da for the cytosolic enzyme whereas the solubilized enzyme of particulate origin has a molecular weight of approx. 110,000 Da. The cytosolic enzyme hydrolyzes a number of α-glycosides in addition to trehalose and, therefore, may be classified as a general α-glucosidase whereas the particulate enzyme exhibits stringent specificity for trehalose. Chemical modification of the particulate trehalase has revealed involvement of carboxyl and imidazole functions in the catalytic mechanism. Of various compounds tested, castanospermine was the most potent inhibitor of the enzyme. |
