Comparison of carbohydrate structures of serum alpha-fetoprotein by sequential glycosidase digestion and lectin affinity electrophoresis
Comparison of carbohydrate structures of serum alpha-fetoprotein by sequential glycosidase digestion and lectin affinity electrophoresis
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DOI：
10.1016/0009-8981(96)06369-3
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发表时间：
1996-10-15
影响因子：
5
通讯作者：
Matsuura, S
中科院分区：
文献类型：
--
作者：
Shimizu, K;Katoh, H;Matsuura, S
血清甲胎蛋白（AFP）是一种糖蛋白，其糖链被认为在恶性肿瘤中显示结构变化。本文对35例良恶性疾病患者血清甲胎蛋白（AFP）糖结构的微观异质性进行了研究。直接、广泛和依次用唾液酸酶、β-半乳糖苷酶和β-N-乙酰己糖胺酶消化血清。消化前后，血清进行了检查，通过凝集素亲和电泳，使用八种凝集素。通过凝集素反应谱和糖苷酶消化的影响，阐明了AFP糖结构与肝脏疾病之间的关系。在良性和恶性肝病患者中，94%以上的AFP糖结构为双触角复合型寡糖。肝癌早期AFP糖结构的变化显示α 1-6岩藻糖加入到还原性末端N-乙酰氨基葡萄糖和单唾液酸化AFP中。在晚期肝细胞癌和产生AFP的肝外恶性肿瘤中，AFP碳水化合物结构的特征在于进一步添加β 1-4 N-乙酰葡糖胺以及半乳糖和N-乙酰葡糖胺残基的异质性。连续糖苷酶消化和凝集素亲和电泳可用于分析血清糖蛋白的糖结构。
Serum alpha-fetoprotein (AFP) is a glycoprotein of which the sugar chain is considered to show structural changes with malignancies. Microheterogeneity of the serum AFP carbohydrate structure was studied in samples from 35 patients with benign and malignant diseases. Sera were digested directly, extensively, and sequentially with sialidase, beta-galactosidase and beta-N-acetylhexosaminidase. Before and after digestion, sera were examined by means of lectin affinity electrophoresis using eight lectins. Relationships between AFP carbohydrate structures and liver diseases were elucidated by the lectin-reactive profiles and the effect of glycosidase digestion. More than 94% of the AFP carbohydrate structures found in patients with benign and malignant liver diseases were biantennary complex-type oligosaccharides. Changes in the AFP carbohydrate structures al the early stage of hepatocellular carcinoma revealed the addition of alpha 1-6 fucose to the reducing terminal N-acetylglucosamine and monosialylated AFPs. In both advanced hepatocellular carcinoma and AFP producing extrahepatic malignancies, AFP carbohydrate structures were characterized as the further addition of beta 1-4 N-acetylglucosamine and heterogeneity in the galactose and N-acetylglucosamine residues. Sequential glycosidase digestion and lectin affinity electrophoresis is useful for analysing the carbohydrate structures of serum glycoprotein.