Gottlieb C, Skinner A M, Kornfeld S
Proc Natl Acad Sci U S A. 1974 Apr;71(4):1078-82. doi: 10.1073/pnas.71.4.1078.
Ricin, a galactose-binding lectin with potent cytotoxic activity, was used to select a clone of Chinese hamster ovary cells with altered plant lectin-binding properties. The clone (15B) is 80-fold less sensitive to the toxic action of ricin than the parent line. In the absence of ricin, it grows both in monolayer and suspension culture with a normal generation time. Plating efficiency, however, is significantly reduced. Relative to the parent cells, its binding of the Ricinus communis lectins, Phaseolus vulgaris erythroagglutinating phytohemagglutinin, Abrus precatorius phytohemagglutinin, and soybean phytohemagglutinin is less than 7%, while binding of lentil phytohemagglutinin, wheat-germ agglutinin, and mushroom phytohemagglutinin is 17%, 40%, and 109%, respectively. In contrast, its concanavalin A binding is increased by 70%. Consistent with these alterations, crude membrane preparations of the 15B cells were found to contain the same sugars as the parent-cell membranes but in different proportions. The 15B membranes have 28% less sialic acid, 38% less N-acetylglucosamine, 49% less galactose, the same amount of N-acetylgalactosamine, and 53% more mannose than the membranes of the parent cells.
蓖麻毒素是一种具有强大细胞毒性活性的半乳糖结合凝集素，被用于筛选具有改变的植物凝集素结合特性的中国仓鼠卵巢细胞克隆。该克隆（15B）对蓖麻毒素的毒性作用的敏感性比亲本细胞系低80倍。在没有蓖麻毒素的情况下，它在单层培养和悬浮培养中均能正常生长，世代时间正常。然而，其平板接种效率显著降低。相对于亲本细胞，它对蓖麻蓖麻凝集素、菜豆红细胞凝集植物血凝素、相思子植物血凝素和大豆植物血凝素的结合率不到7%，而对扁豆植物血凝素、麦胚凝集素和蘑菇植物血凝素的结合率分别为17%、40%和109%。相比之下，其刀豆球蛋白A结合率增加了70%。与这些变化一致，发现15B细胞的粗膜制剂与亲本细胞膜含有相同的糖类，但比例不同。15B细胞膜的唾液酸含量比亲本细胞膜少28%，N-乙酰葡糖胺少38%，半乳糖少49%，N-乙酰半乳糖胺含量相同，甘露糖比亲本细胞膜多53%。
