凝集素亲和层析分析血清GGT寡糖链结构

目的用凝集素亲和层析法,探讨血清GGT在各种肝病时其寡糖链的变化,寻找出肝癌特异性GGT寡糖链结构,为进一步建立简易、特异的小柱亲和层析法分离肝癌特异性GGT奠定基础.方法以唾液酸酶水解GGT糖链末端的唾液酸,再用DSA和ConA亲和层析柱对各种肝病患者血清GGT进行洗脱,结合两种凝集素结合糖链的特性,分析其糖链结构.结果血清经唾液酸酶水解,再用两种凝集素亲和层析后,发现肝病患者GGT糖链结构均有所变化.N糖链天线数肝癌＞良性肝病＞正常人,糖链末端唾液酸量肝癌＞良性肝病＞正常人.肝癌病人出现和DSA强结合组分,该组分不被ConA结合.结论肝癌病人血清GGT可出现和DSA强结合的三天线或四天线N糖链,可利用这一特点建立检测肝癌特异性GGT的凝集素亲和小柱层析法.

The Oligosaccharide Chain Structure of GGT in Serum Was Analyzed With Lectin Affinity Chromatography

Aim In order to look for the especial oligosaccharide chain structure of GGT for Hepatocellular carcinoma,we observed the variation of the oligosaccharide chain of GGT in the sera from patients with different liver diseases by lectin affinity chromatography.Methods The sera were directly hydrolyzed with neuraminidase to remove the terminal sialic acid residues on the sugar chains of GGT and eluted with DSA and ConA affinity chromatography column,the sugar chain structure of GGT was analyzed.Results The sugar chain structure of GGT from patients with different liver diseases had changes.The sequence of terminal sialic acid on sugar chains and of antennary amounts of N-linked sugar chain were following:hepatocellular carcinoma>liver diseases>normal human.Conclusion We observed the fraction that combines strongly to DSA for hepatocellular carcinoma,corresponding to tri- and tetraantennary N-linked sugar chain.Lectin affinity chromatography method can be established to analyze the especial sugar chain structure only existing in Hepatocellular carcinoma below.