摘要
目的 研究小鼠肝细胞膜载脂蛋白 (apo) C 受体与 apo C 、C 、C 及 E的结合特性。方法 用受体的放射性配基结合分析法 (RBA )观察血浆脂蛋白 (VL DL、L DL及 HDL )以及纯化的 apo C 、C 、C 及 E与小鼠肝细胞膜 apo C 受体结合的活性。结果 apo C 受体与 1 2 5I- apo C 的结合能被非标记 apo C 、C 、C 、E及 VL DL抑制 ,其中 apo C 、C 、C 及 VL DL抑制曲线相似 ,以 apo C 的抑制作用最强 ,apo C 次之 ,apo C 最弱 ,apo E与 apo C 受体亦有一定结合 ;而含 apo B10 0的 L DL以及含 apo A 及 apo A 的 HDL和人血清白蛋白则对结合无影响。结论 小鼠肝细胞膜上存在 apo C 受体 ,除能特异结合 apo C 及 VL DL外 ,亦能在一定程度上与apo C 、C 及 E结合。
Objective To observe the effect of unlabeled apoCⅠ,CⅡ,CⅢand E on the binding of 125I-labeled apoCⅢ to mouse liver plasma membranes. Methods Human purified apoCⅢ was labeled with 125I by Chloramine-T method. Mouse liver plasma membrane was prepared by Rays method and the binding activity of apoCⅢ receptor on the liver plasma membranes was measured by the radioligand binding assay of receptors (RBA) developed by this laboratory. Results The apoCⅢ receptors on the mouse liver plasma membrane bound to 125I-labeled human apoCⅢ in a saturable way with Kd 3.31×10 -7mol/L, Bmax was 1.54μg/mg membrane protein. Unlabeled apoCⅠ, CⅡ, CⅢ, E and VLDL could effectively inhibit the binding of 125I-apoCⅢ to the apoCⅢ receptor. The inhibition curve of apoCⅠ, CⅡ and VLDL was similar to that of apoCⅢ. LDL, HDL and human serum albumin could not inhibit the binding of 125I-apoCⅢ to mouse liver plasma membranes. Conclusion The results suggest that apoCⅢ receptors exist on liver plasma membranes and the receptors can not only specifically bind to apoCⅢ but also bind to apoCⅠ, CⅡand E in some degree.
出处
《华西医科大学学报》
CAS
CSCD
北大核心
2002年第3期343-346,共4页
Journal of West China University of Medical Sciences
基金
国家自然科学基金资助 (批准号 39870 2 98)
