人甲胎蛋白异质体肽链和寡糖成分差异与肝癌诊断的关系

Relationship of Human AFP Variant Peptide and Carbohydrate Difference and Clinical Diagnosis of Primary Hepatocellular Carcinoma

采用小扁豆凝集素(LCA)亲和层析法将甲胎蛋白(AFP)分为结合型和非结合型两部分,并分析了人胎儿和原发性肝细胞癌(PHC)患者血清AFP异质体的电泳性质、氨基酸和寡糖成分。发现这两种不同来源的AFP虽同属胎肝型,但电泳性质、氨基酸和寡糖成分仍有差异。PHC血清小扁豆凝集素结合型AFP异质体(AFP-R-LCA)糖链结构中具有岩藻糖残基(α-L-Fuc),这一结构特征的识别,在临床为良性肝病和PHC的鉴别提供理论依据。

AFP from fetal serum and serum of patients with primary hepatic cancer were purified by affinity chromatography. Then, the lentil lectin-reactive and nonreactive variants of these purified glycoproteins were prepared by affinity chromatography with immobilized lectin. Glycopeptides and oligosaccharides were prepared from variants by protease treatment and hydrazinolysis, respectively, and subjected to carbohydrate and amino acid analysis. A small difference in the carbohydrate compositions of each variant was observed. Analysis of chemical compositions of AFP variants is useful for the differential diagnosis between benign liver diseases and primary hepatic cancer.