一种新的糖化低密度脂蛋白受体酶联免疫测定法

A NEW ENZYME IMMUNOASSAY OF RECEPTORS FOR GLYCATED LOW-DENSITY LIPOPROTEINS

人低密度脂蛋白（ＬＤＬ）的羧基先肼化再用辣根过氧化物酶（ＨＲＰ）标记后，与固定于细胞培养板的人胚肺成纤维细胞（ＨＬＦ）进行受体结合反应。结果表明：酶标ＬＤＬ与ＨＬＦ受体特异结合量呈可饱和性，求得ＬＤＬ的最大高亲和结合为１０８ｎｇ／ｍｇ细胞蛋白，表面解离常数为４．７μｇ／ｍｌ；未标记ＬＤＬ可竟争酶标ＬＤＬ与ＨＬＦ的受体特异结合。该法不受ＬＤＬ非酶糖化与否的影响，是测定正常及糖化ＬＤＬ受体特异结合的一种较理想的方法。

he carboxyl radical of human low-density lipoprotein (LDL)was hydrizyded and con-jugated with horseradish peroxidase(HRP-LDL).The HRP-LDL was bound to the LDL re-ceptors in cultured human lung fibroblasts(HLF).The results showed the binding of HRP-LDL to its receptors in HLF was saturated,and the receptor specific and maximum bindingcapicity for the surface binding of the HRP-LDL to its receptors in HLF were 108 ng/mg ofcell protein and 4.7μg/ml.The unlabelled LDL can inhibit competitively the specific bindingof HRP-LDL to its receptors in HLF The assay,which is not affected by nonenzymatic gly-cosylation of LDL,is an ideal assay measuring the specific binding of the normal and glycat-ed LDL in cultured cells.