Morris S A, Bilezikian J P
Arch Biochem Biophys. 1985 Dec;243(2):678-89. doi: 10.1016/0003-9861(85)90546-6.
The mechanisms by which forskolin stimulates adenylate cyclase activity in turkey erythrocyte membranes and is influenced by manganese and Gpp(NH)p were studied. Forskolin-dependent adenylate cyclase activity in particulate turkey erythrocyte membranes is enhanced following preincubation of membranes with isoproterenol and GMP (cleared membranes). In contrast, solubilization of turkey erythrocyte membranes, previously cleared, renders them relatively refractory to forskolin but not to Gpp(NH)p. Whereas adenylate cyclase activity due to the simultaneous presence of forskolin and Mn2+ in particulate turkey erythrocyte membranes is additive, their copresence becomes synergistic after solubilization. The apparent Kact for forskolin activation of adenylate cyclase is not influenced by clearance or by the presence of Mn2+ in particulate turkey erythrocyte membranes. Following solubilization, the Vmax for forskolin-dependent adenylate cyclase activation determined in the presence of Mn2+ is also independent of clearance. Forskolin activation of turkey erythrocyte adenylate cyclase appears to be influenced at sites in addition to the catalytic unit.
研究了福斯高林刺激火鸡红细胞膜中腺苷酸环化酶活性的机制以及锰和Gpp(NH)p对其的影响。在用异丙肾上腺素和GMP预孵育膜（清除后的膜）后，颗粒状火鸡红细胞膜中依赖福斯高林的腺苷酸环化酶活性增强。相比之下，先前清除过的火鸡红细胞膜经溶解后，对福斯高林相对不敏感，但对Gpp(NH)p仍敏感。虽然在颗粒状火鸡红细胞膜中，福斯高林和Mn2+同时存在时腺苷酸环化酶活性是相加的，但溶解后它们的共同存在变得具有协同性。颗粒状火鸡红细胞膜中福斯高林激活腺苷酸环化酶的表观Kact不受清除或Mn2+存在的影响。溶解后，在Mn2+存在下测定的依赖福斯高林的腺苷酸环化酶激活的Vmax也与清除无关。火鸡红细胞腺苷酸环化酶的福斯高林激活似乎除了催化单元外还受其他位点的影响。
