PURIFICATION, CHARACTERIZATION, AND EXPRESSION OF RAT EPIDIDYMAL BETA-D-GALACTOSIDASE

The purpose of the present study is to purify, kinetically characteriz e and measure the amount of soluble acid beta-D-galactosidase (EC 3.2. 1.23) in different anatomical regions (caput, corpus, and cauda) of th e adult rat epididymis. Based upon SDS-PAGE analysis, the subunit mole cular mass of the caput and cauda enzyme is similar to 85,000 daltons while the corpus enzyme is similar to 50,000 daltons. The apparent K-m and V-max values are 67, 24, and 59 mu M and 5.0, 1.88, and 6.3 mu M/ min./-mg protein for the enzyme purified from the caput, corpus, and c auda regions of the epididymis, respectively. However, no regional dif ferences in the amount of soluble enzyme protein are observed. These d ata demonstrates regional differences in the activity of epididymal ac id beta-D-galactosidase and suggest that the observed regional differe nces in enzyme activity may be due to posttranslational modifications.