兔肝LDL受体对LDL的结合特性研究

BINDING CHARACTERISTICS OF RABBIT LIVER LDL RECEPTOR

为了研究兔低密度脂蛋白（ＬＤＬ）受体的生化特性，从家兔肝细胞膜分离得到ＬＤＬ受体，用酶联免疫受体分析技术检测ＬＤＬ与制备物的结合活性，通过Ａ４９０－ＬＤＬ定量转换标准曲线对制备物结合的ＬＤＬ进行定量。实验表明兔肝受体制备物对ＬＤＬ具有特异性结合的活性；与ＬＤＬ的结合在２ｈ内达到最大值；随着ＬＤＬ浓度的增加，与受体制备物结合的量也逐渐增加，当ＬＤＬ浓度达到５０μｇ／ｍｌ时结合反应趋向饱和。饱和曲线分析表明：制备物特异性结合ＬＤＬ的Ｋｄ值为５．９μｇ／ｍｌ，最大结合容量为２２２ｎｇ／ｍｇ蛋白质。

A rabbit liver LDL receptor was prepared to study its binding features. The binding activity was measured with the enzyme-linked immunoreceptor assay. This preparation was shown to have specific binding activity with LDL. The binding activity reached its maximum within 2 hours.Its binding activity with the increase of LDL concentration and became saturated when the later was 50μg/ml.Receptor specific Kd and maximum binding capacity calculated with Scatchard plot were 5.9 μg/ml and 222 ng/mg protein,respectively.