Costa B, Giusti L, Martini C, Lucacchini A
Istituto Policattedra di Discipline Biologiche, Universita di Pisa, Italy.
Neurochem Int. 1996 Dec;29(6):623-7. doi: 10.1016/s0197-0186(96)00060-5.
The modification of [3H]nitrendipine binding sites in rabbit brain membranes with 2,3-butanedione and diethylpyrocarbonate was investigated. 2,3-Butanedione, an arginine-specific reagent, causes a dose- and time-dependent decrease in the number of [3H]nitrendipine binding sites without altering its dissociation constant. Scatchard analysis of the binding data shows that 50 mM 2,3-butanedione decreases the binding capacity of [3H]nitrendipine from a control value of 71 +/- 6 fmol/mg of protein to 40 +/- 3 fmol/mg of protein. Complete and selective protection against inactivation is provided by nifedipine. No decrease of [3H]nitrendipine binding occurs when membranes are pretreated with selective histidine reagent diethylpyrocarbonate. The results indicate that arginine but not histidine residue in L-type calcium channel domain in critical for [3H]nitrendipine binding.
研究了用2,3-丁二酮和焦碳酸二乙酯对兔脑膜中[3H]尼群地平结合位点的修饰作用。2,3-丁二酮是一种精氨酸特异性试剂，可导致[3H]尼群地平结合位点数量呈剂量和时间依赖性减少，而不改变其解离常数。对结合数据进行Scatchard分析表明，50 mM 2,3-丁二酮可使[3H]尼群地平的结合能力从对照值71±6 fmol/mg蛋白质降至40±3 fmol/mg蛋白质。硝苯地平可提供完全且选择性的失活保护。用选择性组氨酸试剂焦碳酸二乙酯预处理膜时，[3H]尼群地平结合无减少。结果表明，L型钙通道结构域中的精氨酸残基而非组氨酸残基对[3H]尼群地平结合至关重要。
