Ishikawa Y, Charalambous P, Matsumura F
Pesticide Research Center, Michigan State University, East Lansing 48824.
Biochem Pharmacol. 1989 Aug 1;38(15):2449-57. doi: 10.1016/0006-2952(89)90088-9.
The effects of pyrethroids and DDT on the alpha-subunit protein of the rat brain sodium channel were studied by using both native and exogenously added cAMP-dependent protein kinases. For this purpose, the sodium channel was partially purified, using the method of Hartshorne and Catterall [J Biol Chem 259: 1667-1675, 1984], and 32P-phosphorylated using [gamma-32P]ATP and exogenously added catalytic subunit of cAMP-dependent protein kinase. By comparing the phosphorylation patterns of the isolated sodium channel to those of the partially purified or unpurified (i.e. intact synaptosomes) preparations, it was concluded that the alpha-subunit of the voltage-sensitive sodium channel protein is the only phosphorylatable protein present at the 260 kD molecular weight range on the sodium dodecyl sulfate-polyacrylamide gel electrophoretogram. Phosphorylation of the alpha-subunit was induced by depolarization, and this process was inhibited by 10(-6) to 10(-10) M 1R-deltamethrin, but not by 1S-deltamethrin, the latter being an inactive enantiomer of the former. DDT produced a similar effect, but only at a higher concentration range. By using lysed synaptosomal membranes, it was possible to study the direct effects of these compounds on the alpha-subunit, which were similar to those produced by depolarization of intact synaptosomes.
运用天然的和外源性添加的环磷酸腺苷（cAMP）依赖性蛋白激酶，研究了拟除虫菊酯和滴滴涕对大鼠脑钠通道α亚基蛋白的影响。为此，采用Hartshorne和Catterall [《生物化学杂志》259: 1667 - 1675, 1984]的方法对钠通道进行部分纯化，并用[γ - 32P]ATP和外源性添加的cAMP依赖性蛋白激酶催化亚基进行32P磷酸化。通过将分离的钠通道的磷酸化模式与部分纯化或未纯化（即完整突触体）制剂的磷酸化模式进行比较，得出结论：电压敏感性钠通道蛋白的α亚基是十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳图谱上分子量在260 kD范围内唯一可磷酸化的蛋白。α亚基的磷酸化由去极化诱导，此过程受到10(-6)至10(-10) M的1R - 溴氰菊酯抑制，但不受1S - 溴氰菊酯抑制，后者是前者的无活性对映体。滴滴涕产生类似效果，但仅在较高浓度范围内。通过使用裂解的突触体膜，有可能研究这些化合物对α亚基的直接影响，这些影响与完整突触体去极化所产生的影响相似。
