Leijten L, Wilce P A, Davidson M, Banks M, Martin L
Biochem J. 1987 Jan 1;241(1):279-84. doi: 10.1042/bj2410279.
The regulation of 3-hydroxy-3-methylglutaryl-CoA reductase was studied in mouse uterine epithelium. The enzyme was rapidly inactivated during incubation with ATP/Mg2+ in vitro, and could be re-activated by incubation with partially purified rat liver phosphoprotein phosphatase. Enzyme activity was rapidly inhibited by mevalonate injection in vivo to approx. 30% of control. The percentage of total enzyme active in vivo was measured by inclusion of NaF in the isolation buffers. The percentage of enzyme active in vivo 18 h after stimulation by oestrogens remained at approx. 25% after inhibition of activity by mevalonate injection, cholesterol feeding or progesterone pretreatment. However, 9 h after oestrogen stimulation, cholesterol feeding inhibited enzyme activity to 57% of control, 94% of which was in the active form. We conclude that, although all components for a reversible phosphorylative regulation of 3-hydroxy-3-methylglutaryl-CoA reductase activity are present in uterine epithelial cells, a role in the rapid changes in epithelial enzyme activity has not been demonstrated.
对小鼠子宫上皮中3-羟基-3-甲基戊二酰辅酶A还原酶的调节进行了研究。该酶在体外与ATP/Mg2+孵育期间迅速失活，并且通过与部分纯化的大鼠肝脏磷蛋白磷酸酶孵育可重新激活。在体内，甲羟戊酸注射可使酶活性迅速受到抑制，降至对照的约30%。通过在分离缓冲液中加入氟化钠来测量体内总活性酶的百分比。在用甲羟戊酸注射、胆固醇喂养或孕酮预处理抑制活性后，雌激素刺激18小时后体内活性酶的百分比仍保持在约25%。然而，在雌激素刺激9小时后，胆固醇喂养将酶活性抑制至对照的57%，其中94%为活性形式。我们得出结论，虽然子宫上皮细胞中存在对3-羟基-3-甲基戊二酰辅酶A还原酶活性进行可逆磷酸化调节的所有成分，但尚未证明其在上皮酶活性快速变化中的作用。
