Breen K C, Potratz A, Georgopoulou N, Sandhoff K
Department of Pharmacology and Clinical Pharmacology, University of Dundee, Ninewells Hospital Medical School, Dundee, Scotland, UK.
Glycoconj J. 1998 Feb;15(2):199-202. doi: 10.1023/a:1006980608983.
In order to examine the effects of altered protein sialylation on neural cell function, B104 rat neuroblastoma cells were stably transfected with the cDNA coding for alpha2,6(N) sialyltransferase (ST(6)N). Lectin blot analysis of the clones demonstrated an increase in staining of the Sambucus nigra lectin, which detects alpha2,6 linked sialic acid, in parallel with enzyme activity. There was a concomitant decrease in staining by the Maackia amurensis lectin which labels alpha2,3-linked sialic acid, indicating that the individual sialyltransferase enzymes may compete for penultimate galactose acceptor sites. While there was an initial increase in protein-bound sialic acid in parallel with enzyme activity, the sialylation of the cells was demonstrated to be saturable. There was an inverse relationship between cell adhesion to a fibronectin substrate and ST(6)N activity suggesting that the negatively charged sugar acts to modulate cell-substrate interaction. These cells will provide an ideal model system with which to further investigate the effect of altered sialic acid on neural cell function.
为了研究蛋白质唾液酸化改变对神经细胞功能的影响，用编码α2,6(N)唾液酸转移酶（ST(6)N）的cDNA对B104大鼠神经母细胞瘤细胞进行稳定转染。对克隆进行凝集素印迹分析表明，检测α2,6连接唾液酸的黑接骨木凝集素染色增加，且与酶活性平行。同时，标记α2,3连接唾液酸的山嵛菜凝集素染色减少，表明单个唾液酸转移酶可能竞争倒数第二个半乳糖受体位点。虽然蛋白质结合唾液酸最初与酶活性平行增加，但细胞的唾液酸化被证明是可饱和的。细胞与纤连蛋白底物的黏附与ST(6)N活性呈负相关，表明带负电荷的糖可调节细胞与底物的相互作用。这些细胞将为进一步研究唾液酸改变对神经细胞功能的影响提供理想的模型系统。
