Enyedi P, Williams G H
Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.
J Biol Chem. 1988 Jun 15;263(17):7940-2.
Bovine adrenal cortical microsomes possess high (Kd = 3.68 +/- 1.02 X 10(-9) M) and lower (Kd = 9.20 +/- 1.71 X 10(-8) M) affinity binding sites for inositol 1,3,4,5-tetrakisphosphate. The binding to these sites is rapid, saturable (reaches equilibrium by 15 min at 0 degrees C), and reversible. Competition studies with other inositol phosphate analogs indicate that the high affinity binding sites are clearly distinct from the inositol 1,4,5-trisphosphate receptors which are, however, responsible for a fraction of the lower affinity binding. The characteristics of the inositol 1,3,4,5-tetrakisphosphate binding sites described are compatible with their possible receptor function.
牛肾上腺皮质微粒体对肌醇1,3,4,5 - 四磷酸具有高亲和力（Kd = 3.68 +/- 1.02 X 10(-9) M）和低亲和力（Kd = 9.20 +/- 1.71 X 10(-8) M）结合位点。与这些位点的结合迅速、可饱和（在0摄氏度下15分钟达到平衡）且可逆。与其他肌醇磷酸类似物的竞争研究表明，高亲和力结合位点与肌醇1,4,5 - 三磷酸受体明显不同，然而，肌醇1,4,5 - 三磷酸受体负责部分低亲和力结合。所描述的肌醇1,3,4,5 - 四磷酸结合位点的特征与其可能的受体功能相符。
