Shlykov S G, Slinchenko N N, Kurskiĭ M D
Ukr Biokhim Zh (1978). 1987 Jan-Feb;59(1):82-6.
Adenylate cyclase of plasma membranes from the nonpregnant rabbit myometrium shows the maximum activity at pH 7.7-7.9, is characterized by apparent Km for ATP amounting to 0.38 +/- 0.09 mM, V--125 +/- 34.4 pmol min/mg protein, is activated at most by 15-20 mM Mg2+ and F-. Adenylate cyclase of plasma membranes from the pregnant rabbit myometrium is characterized by apparent Km for ATP amounting to 0.74 +/- 0.06 mM, V--77.3 +/- 6.0 pmol/min/mg protein, is activated at most by 5-10 mM Mg2+ and 10-15 mM F-; the pH optimum for the adenylate cyclase in this functional state is 7.3. Adenylate cyclase in the state of labour is characterized by apparent Km for ATP amounting to 0.46 +/- 0.11 mM, V--34.8 +/- 4.6 pmol/min/mg protein, is activated at most by 10-15 mM Mg2+ and F-, shows the same activity at pH 7.3-8.5. Adenylate cyclase of myometrium in three investigated states is activated by 2 mM EGTA; 10(-7) M Ca2+ decreases activation caused by EGTA; higher concentrations of Ca2+ decrease the basal activity of the enzyme.
未孕兔子宫肌层质膜的腺苷酸环化酶在pH 7.7 - 7.9时活性最高，其对ATP的表观Km值为0.38±0.09 mM，V为125±34.4 pmol·min/mg蛋白，最多被15 - 20 mM Mg2+和F-激活。孕兔子宫肌层质膜的腺苷酸环化酶对ATP的表观Km值为0.74±0.06 mM，V为77.3±6.0 pmol/min/mg蛋白，最多被5 - 10 mM Mg2+和10 - 15 mM F-激活；在此功能状态下，腺苷酸环化酶的最适pH为7.3。分娩时的腺苷酸环化酶对ATP的表观Km值为0.46±0.11 mM，V为34.8±4.6 pmol/min/mg蛋白，最多被10 - 15 mM Mg2+和F-激活，在pH 7.3 - 8.5时活性相同。所研究的三种状态下子宫肌层的腺苷酸环化酶均可被2 mM EGTA激活；10(-7) M Ca2+可降低EGTA引起的激活作用；较高浓度的Ca2+会降低该酶的基础活性。
