Studies on the heterogeneity of mammalian β-glucuronidases

1. 1. Gel electrophoresis showed that the liver of rabbit (Oryctolegus cuniculus), and probably of rat (Rattus norvegicus), contains molecular size variants of β-glucuronidase corresponding to those of mouse (Mus musculus) tiflaes (described by Swank & Paigen, 1973). 2. 2. Experiments on charge characteristics, immunological relationships, interconversion and subcellular distribution of the enzyme forms in rabbit liver provided no evidence for the inclusion in the larger molecular size forms of an accessory polypeptide very different from the subunit of the smaller tetrameric forms. 3. 3. Extracts of microsomal and lysosomal fractions from rabbit liver differed only quantitatively in their complements of β-glucuronidase forms.