Estrone-and dehydroepiandrosterone-sulfatase activities in human female epidermis

Estrone (E1)-sulfatase and dehydroepiandrosterone (DHEA)-sulfatase activities were studied in human female epidermis. Skin specimens were obtained by abdominal or plantar biopsies. The apparent Michaelis-Menten constants for E1 and DHEA sulfatase were 35.2 μM and 8.7 μM, respectively. A substrate inhibition was only observed for DHEA sulfatase. Both sulfatases had an elevated temperature optimum (65°C). The effect of inorganic salts was also tested. In normal epidermis, E1-sulfatase activity was constantly higher than DHEA-sulfatase activity, but no correlation between these activities was observed. On the other hand, E1-and DHEA-sulfatase activities were lower in plantar than in abdominal epidermis. In plantar epidermis of palmoplantar keratoderma, large variations in E1-sulfatase activity, but no significant variation in DHEA-sulfatase activity, were obseved. In human epidermis, the findings were consistent with the existence of two different sulfatases: E1 sulfatase and DHEA sulfatase. It would also appear that sulfatase activities are not linked to the abnormal shedding of plantar stratum corneum in palmoplantar keratoderma.