Irvine R F, Brown K D, Berridge M J
Biochem J. 1984 Aug 15;222(1):269-72. doi: 10.1042/bj2220269.
Swiss-mouse 3T3 cells permeabilized with saponin were used to study the specificity of the inositol trisphosphate-induced release of 45Ca2+ from their intracellular stores. Inositol 1,4,5-trisphosphate was the most potent compound studied (dose giving half-maximal effect 0.3 microM). 45Ca2+ was also released by inositol 2,4,5-trisphosphate, glycerophosphoinositol 4,5-bisphosphate and inositol 4,5-bisphosphate, with doses giving half-maximal effect of respectively 1.6 microM, 1.6 microM and 20 microM, but not by inositol 1,4-bisphosphate (50 microM). These data suggest that the trans-vicinal phosphates on the 4- and 5-positions are essential for the Ca2+-mobilizing effect of inositol trisphosphate, and that in addition there is a requirement for a phosphate group on the opposite side of the molecule, with a preference for the 1-position.
用皂角苷通透处理的瑞士小鼠3T3细胞用于研究肌醇三磷酸诱导细胞内储存的45Ca2+释放的特异性。肌醇1,4,5-三磷酸是所研究的最有效的化合物(产生半数最大效应的剂量为0.3微摩尔)。肌醇2,4,5-三磷酸、甘油磷酸肌醇4,5-二磷酸和肌醇4,5-二磷酸也能释放45Ca2+,产生半数最大效应的剂量分别为1.6微摩尔、1.6微摩尔和20微摩尔,但肌醇1,4-二磷酸(50微摩尔)不能。这些数据表明,4位和5位上的反式邻位磷酸对于肌醇三磷酸的钙动员效应至关重要,此外,分子另一侧还需要一个磷酸基团,优先在1位。