Stein P J, Halliday K R, Rasenick M M
J Biol Chem. 1985 Aug 5;260(16):9081-4.
In this report, we show that fluoride activates dark-adapted rod outer segment phosphodiesterase, and that this activation is mediated, in analogy with adenylate cyclase, through a GTP binding protein. The GTP binding protein is released from dark-adapted rod outer segment membranes by exposure to fluoride and subsequent centrifugation. The 39-kilodalton subunit of the GTP binding protein, released from the membrane by this procedure, exhibits altered susceptibility to limited trypsin proteolysis, identical to that seen when hydrolysis-resistant GTP analogs are bound to that subunit. Repeated exposure of dark-adapted rod outer segment membranes to fluoride and subsequent centrifugation results in maximal activation of the membrane-bound phosphodiesterase. Thus, activation of phosphodiesterase by fluoride in the dark appears similar to fluoride activation of adenylate cyclase.
在本报告中，我们表明氟化物可激活暗适应的视杆细胞外段磷酸二酯酶，并且这种激活类似于腺苷酸环化酶，是通过一种GTP结合蛋白介导的。通过暴露于氟化物并随后离心，可从暗适应的视杆细胞外段膜中释放出GTP结合蛋白。通过该程序从膜中释放的GTP结合蛋白的39千道尔顿亚基，对有限的胰蛋白酶消化表现出改变的敏感性，这与当抗水解的GTP类似物与该亚基结合时所观察到的情况相同。将暗适应的视杆细胞外段膜反复暴露于氟化物并随后离心，会导致膜结合的磷酸二酯酶最大程度地激活。因此，黑暗中氟化物对磷酸二酯酶的激活似乎类似于氟化物对腺苷酸环化酶的激活。
