Takanashi K, Watanabe K, Yoshizawa I
Hokkaido Institute of Pharmaceutical Sciences, Japan.
Biol Pharm Bull. 1993 Mar;16(3):217-9. doi: 10.1248/bpb.16.217.
When estradiol 17-sulfate (ES) was incubated with human placental microsomes under an NADPH-generating system, 2- and 4-hydroxyestradiol 17-sulfates (2- and 4-OH-ES) formed as the main products. By kinetic experiments, the apparent Km values of 44.0 and 360 microM and apparent Vmax values of 236 and 140 pmol/mg protein/10 min were obtained for the 2- and 4-hydroxylation, respectively. The results indicate that human placental microsomes have fairly high 2- and 4-hydroxylase activities toward ES. This paper describes the formation of 2- and 4-OH-ES and speculates on their physiological role during pregnancy.
在NADPH生成系统下，将硫酸雌二醇17 - 硫酸盐（ES）与人胎盘微粒体一起温育时，主要生成2 - 羟基雌二醇17 - 硫酸盐和4 - 羟基雌二醇17 - 硫酸盐（2 - 和4 - OH - ES）。通过动力学实验，2 - 羟化和4 - 羟化的表观Km值分别为44.0和360微摩尔，表观Vmax值分别为236和140皮摩尔/毫克蛋白质/10分钟。结果表明，人胎盘微粒体对ES具有相当高的2 - 羟化酶和4 - 羟化酶活性。本文描述了2 - 和4 - OH - ES的形成，并推测了它们在孕期的生理作用。
