摘要
维生素A类化合物对糖蛋白N-连接型糖链(简称N-糖链)结构的影响,近年来在研究其作用机制中颇受重视。本文研究视黄酸(RA)对大鼠皮肤上皮基底培养细胞表面膜糖蛋白糖链结构作用,发现RA促进N-糖链合成,使~3H-甘露糖掺入糖链量增加43.5％,RA可改变N-糖链的类型,促进复杂型N-糖链合成,表现为增加三、四天线复杂型N-糖链合成而不是二天线;RA还使含分叉性GIeNAc和核心Fuc的百分比上升。本文还用细胞电泳方法研究膜表面唾液酸相对量,发现RA可引起唾液酸含量下降。结果提示RA对N-糖链结构的影响,是其多种生物学作用的可能途径之一。
We studied the effect of RA on the structure of N-linked oligosaccharides of surface glycoproteins isolated from cultured keratinocytes. The results show that RA can stimulate the synthesis of N-linked oligosaccharides with 43.5 % of 3H-man-nose incorporation into N-linked oligosaccharides ;RA alters the type ratio of N-linked oligosaccharides with the increase of complex type percentage, for which only the tri- and tetra-antennary will response but not the biantennary ;RA makes the complex type contain more bisecting GlcNAc and core fucose. The relative amount of sialic acid on cell surface has been declined due to the RA action as demonstrated by cell electrophoresis.These results suggest that the effect of RA on N-linked oligosaccharides might be one of the mechanism for its biological function.
