Estrone β-glucosidase activity in human placenta

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Abstract
The 105,000 g supernatant from human placental homogenates, prepared in the presence of sodium taurocholate and Cutscum, contained .beta.-glucosidase activity towards estrone glucoside and towards 4-methylumbelliferyl glucoside (4-MU-glucoside) and glucocerebroside. After partial purification, the estrone glucosidase was active only after the addition of negatively charged phospholipid, whereas the other .beta.-glucosidases did not exhibit this requirement. The estrone glucosidase was separated from the 4-MU-glucosidase by chromatography on Sephadex G-200 with 0.1% sodium taurocholate in the eluting buffer. The estrone glucosidase was mainly contained in material with an isoelectric point of 4.7, while the 4-MU-glucosidase was distributed in fractions with pI values of 4.7 and 6.2-6.4. The partially purified estrone glucosidase had a pH optimum of 5.8, as distinct from that of 6.4 found for the 4-MU-glucosidase, and differed markedly from the 4-MU-glucosidase in its response to treatment with heat, sulfhydryl reagents and detergents. Its sensitivity to changes in pH differed from those reported for glucocerebrosidase.