Separation and properties of beta-galactosidase, beta-glucosidase, beta-glucuronidase and N-acetyl-beta-glucosaminidase from rat kidney.

1. The activities of beta-galactosidase, beta-glucosidase, beta-glucuronidase and N-acetyl-beta-glucosaminidase from rat kidney have been compared when 4-methylumbelliferyl glycosides are used as substrates. 2. Separation by gel electrophoresis at pH7.0 indicated slow- and fast-moving components of rat-kidney beta-galactosidase. 3. The fast-moving component is also associated with the total beta-glucosidase activity and inhibition experiments indicate that a single enzyme species is responsible for both activities. 4. DEAE-cellulose chromatography and filtration on Sephadex gels suggests that the beta-glucosidase component is a small acidic molecule, of molecular weight approx. 40000-50000, with optimum pH5.5-6.0 for beta-galactosidase and beta-glucosidase activities. 5. The major beta-galactosidase component has low electrophoretic mobility, a calculated molecular weight of 80000 and optimum pH3.7.