Jokinen M, Ulmanen I, Andersson L C, Kääriäinen L, Gahmberg C G
Eur J Biochem. 1981 Feb;114(2):393-7. doi: 10.1111/j.1432-1033.1981.tb05159.x.
The human erythroid cell line, K562, synthesizes the major red cell sialoglycoprotein, glycophorin A. We have isolated an mRNA fraction which codes for glycophorin A from K562 cells and studied the synthesis of the sialoglycoprotein in a rabbit reticulocyte cell-free system. In the absence of membranes a precursor form of glycophorin A was synthesized. This was identified using specific anti-(glycophorin A) serum. The apparent molecular weight of the carbohydrate-free precursor of glycophorin A was 19 500. This exceeds the molecular weight of the glycophorin A apoprotein by approximately 5000. In the presence of membranes from dog pancreas, the synthesized glycophorin A precursor was N-glycosylated and probably also O-glycosylated. The oligosaccharide chains remained incomplete and the glycoprotein synthesized in vitro corresponded to the glycosylated precursor of glycophorin A obtained in intact cells.
人红系细胞系K562能合成主要的红细胞唾液酸糖蛋白血型糖蛋白A。我们从K562细胞中分离出编码血型糖蛋白A的mRNA组分，并在兔网织红细胞无细胞体系中研究了该唾液酸糖蛋白的合成。在无膜的情况下，合成了血型糖蛋白A的前体形式。使用特异性抗（血型糖蛋白A）血清对其进行了鉴定。血型糖蛋白A无糖基化前体的表观分子量为19500。这比血型糖蛋白A载脂蛋白的分子量大约超出5000。在存在狗胰腺膜的情况下，合成的血型糖蛋白A前体进行了N-糖基化，可能也进行了O-糖基化。寡糖链仍不完整，体外合成的糖蛋白与完整细胞中获得的血型糖蛋白A的糖基化前体相对应。
