β-d-Glucosidases and related enzymic activities in pig kidney

Abstract

1. The β-glucosidase activity of pig kidney is located in the unsedimentable fraction of the cell and is not associated with the lysosomes. 2. The enzyme is active towards β-d-glucosides, β-d-galactosides, β-d-xylosides and α-l-arabinosides. 3. These activities could not be separated by gel electrophoresis, gel filtration or DEAE-cellulose chromatography. 4. Response to inhibitors, heat-denaturation and competitive substrates suggests that a single active site is responsible for all four activities. 5. Two forms of the enzyme were found to occur either separately or together in kidneys of pigs from several different breeds. 6. Electro-focusing experiments show these to have a small difference in isoelectric point (4·9 and 5·1), and gel filtration gives an approximate molecular weight of 50000 for both forms. 7. The characteristics of these two enzymes are compared.