鲫鱼籽唾液酸糖蛋白的N-糖链结构及生物活性

N-Glycan structure and bioactivity of sialoglycoprotein from crucian carp eggs

鲫鱼是常规食用淡水鱼,其鱼籽含有大量唾液酸化糖蛋白。对鲫鱼籽糖蛋白进行纯化,研究其N-糖链结构和生物活性。结果发现:鲫鱼籽糖蛋白分子量主要分布在19.7×10^4、2.7×10^4和2.2×10^4左右。利用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)解析主要糖蛋白上N-糖链,发现其N-糖链结构主要为双天线型或三天线型分叉结构,末端唾液酸结合在半乳糖或N-乙酰氨基-半乳糖上。生物活性分析表明,鲫鱼籽糖蛋白具有阻止磷酸钙沉淀能力和一定清除DPPH自由基能力,对HaCat细胞具有促生长能力,并具有较强的促凝血活性。

Crucian carp(Carassius auratus)is a common freshwater fish in Chinese kitchen,and crucian carp egg contains a lot of sialoglycoproteins(CcSGP).In this work,the purification of SGP from crucian carp eggs,N-glycan structure and biological activity of CcSGP are investigated.Results show that CcSGP are rich in sialic acid,and the molecular weight distribution includes glycoprotein of 19.7×10^4,2.7×10^4 and 2.2×10^4.N-glycans analysis of CcSGP by MALDI-TOF mass spectrometry indicates that most of the N-glycan structure consists of double-antenna or tri-antenna structure,and the terminal sialic acid is bound to galactose or N-acetylgalactosamine.Bioactivity analysis indicates that CcSGP has the ability to prevent calcium phosphate precipitation and certain free radicals scavenging capacity of DPPH.Also,CcSGP has growth-promoting ability for HaCat cells and distinct procoagulant activity.