摘要
凝集素是一种能同复合糖中不同糖基序列特异性相结合的糖结合蛋白质。本文在研究二乙基亚硝胺诱发肝癌中碱性磷酸酶(ALP)活力和同工酶的基础上,利用四种固相凝集素柱组成的序列亲和层析,配合外切糖苷酶β-N-酰氨基葡萄糖苷酶,研究了诱发肝癌ALP糖链中“Bisecting”GlcNAc残基的变化。研究结果表明:(1)大鼠诱发肝癌ALP的活性较正常肝脏明显增高,其性质和正常肝脏ALP基本相同,两者均属于组织非特异性ALP,提示大鼠肝癌发生过程中没有同工酶谱的变化。(2)大鼠诱发肝癌ALP糖链的“Bisecting”GlcNAc残基含量较正常鼠肝明显增加。
Lectins are sugar-binding proteins that can bind specifically to definite sugar sequence in oligosaccharides or glycopeptides. In the present study, using serial lectin affinity chromatography combined with exo-glycosidases, we studied the difference in 'bisecting' GlcNAa residue of alkaline phosphatases (ALP) from normal rat liver and rat hepatoma induced by diethylnitrosamine. In order to verify the structural changes of sugar chain were caused by the changes of ALP type or the changes of sugar chain in the same type of ALP isozyme, the electrophoretic profiles and some Characteristics of ALP isozyme pattern in normal rat liver and induced rat hepatoma were compared.The results showed that ( 1 ) the activity of ALP in induced rat hepatoma was markly increased and its characteristics were identical with that of normal rat liver. Both were tissue unspecific ALP, which suggested that there was no ALP isozyme change in rat hepatoma; (2) the amount of 'bisectingn GlcNAc residues on induced rat hepatoma ALP was obviously increased.
关键词
肝癌
碱性磷酸酶
凝集素
Alkaline phosphatase, Lectin, “Bisecting” GlcNAc
