唾液酸单体对兔红细胞膜钙调蛋白和脂质过氧化的影响  

Impacts of Sialic Acid Analogues on Calmodulin and Lipoperoxidationof Erythrocyte Membrane of Rabbits

作　　者：卢大用[1] 陈恩鸿[2] 曹静懿[1] 周建军 龚镥[1] 胥彬[2] 

机构地区：[1]上海大学生命科学学院,上海200436 [2]中国科学院上海药物研究所,上海200031

出　　处：《上海大学学报（自然科学版）》2001年第3期253-257,共5页Journal of Shanghai University:Natural Science Edition

基　　金：上海高等教育科学技术发展基金 ( 97A49)资助项目

摘　　要：唾液酸是自然界存在量最大的带负电的碳水化合物 ,母体结构为 9个碳原子组成的内环氨基糖 .为研究唾液酸单体与在生物大分子中的唾液酸的相关性 ,寻找唾液酸的新生物途径 ,作者使用纯唾液酸单体 5 -乙酰神经氨酸、5 -羟乙酰神经氨酸和唾液酸酶研究红细胞钙调蛋白和脂质过氧化作用 .结果表明这二个唾液酸单体能抑制兔红细胞中的钙调蛋白和促进兔红细胞的脂质过氧化 ,二个唾液酸单体生物活性呈现浓度效应相关性 .在等摩尔浓度下 ,5 -羟乙酰神经氨酸的作用较 5 -乙酰神经氨酸强 2～ 4倍 .相应地 ,用唾液酸酶降解兔红细胞膜上的唾液酸大分子到单体也使抑制钙调蛋白活性 .因此 ,作者认为唾液酸单体在机体中也有生物活性 ,它们从生物大分子中游离下来能改变生物活性 .唾液酸 5 (N)位置可能与其生物活性相关 .Sialic acids are a series of 9 carbon amino sugars and most abundant among negative charged carbohydrates in nature. In order to investigate correlation between free sialic acids monosaccharides and sialic acid connected to large molecules, and novel biological pathways of sialic acids, pure sialic acid analogues (5 acetylneuraminic acid, 5AcNeu and N glycolylneuraminic acid, NeuGc) and a neuraminidase were applied to study the calmodulin and lipoperoxidation action on rabbit erythrocytes. It has been shown that these two single forms of sialic acids can suppress calmodulin activity as well as activate lipoperoxidation on the erythrocyte membrane of rabbits. These two activities are proportional to sialic acid concentrations. In addition, the effect of NeuGc is almost 2~4 fold higher than that of 5 AcNeu on both biopathways in equivalent concentrations. Accordingly, calmodulin activity is partly blocked when sialic acids in large molecules are cleavaged to single forms by a neuraminidase from erythrocyte membrane of rabbit. Thus we conclude that single form of sialic acids may have altered bioactivities from sialic acids in macromolecules and have their own biological activities. 5(N) position may be one of critical sites for the bioactivity of sialic acids.

关 键 词：唾液酸 钙调蛋白 脂质过氧化 肿瘤 唾液酸酶 兔红细胞 生物活性 

分 类 号：Q532.5[生物学—生物化学]