Decastel M, Haentjens G, Aubery M, Goussault Y
Laboratoire de Biologie et Pathologie moléculaires des Glycoprotéines, C.N.R.S.-U.A. n. 71, I.N.S.E.R.M. U. n. 180, U.E.R. Biomédicale des Saints-Pères, Paris.
C R Acad Sci III. 1988;307(4):165-70.
The binding to and toxicity of ricin on Zajdela hepatoma ascites cells were studied. The kinetic analysis of [125I]-ricin binding to hepatoma cells indicated that maximal specific binding was reached within 30 min. at 4 degrees C and 60 min. at 25 degrees C and that toxin binding to hepatoma cells was saturable. When the binding data were plotted according to the method of Scatchard, curvilinear graphs were obtained suggesting that hepatoma cells have both high and low affinity receptors for ricin. The number of high and low affinity receptors was identical at 4 and 25 degrees C, i.e., 8 x 10(5) and 1.2 x 10(7) sites per cell respectively. However, the capacity of hepatoma cells to bind ricin is stronger at 4 degrees C than at 25 degrees C. The toxic activity of ricin was totally abolished in the presence of lactose suggesting that ricin binding to cells occurs through binding sites containing galactosyl residues.
研究了蓖麻毒素对Zajdela肝癌腹水细胞的结合作用和毒性。[125I] -蓖麻毒素与肝癌细胞结合的动力学分析表明，在4℃下30分钟内、25℃下60分钟内达到最大特异性结合，且毒素与肝癌细胞的结合是可饱和的。当按照Scatchard法绘制结合数据时，得到曲线图形，表明肝癌细胞对蓖麻毒素具有高亲和力和低亲和力受体。在4℃和25℃时，高亲和力和低亲和力受体的数量相同，即分别为每个细胞8×10⁵个位点和1.2×10⁷个位点。然而，肝癌细胞在4℃下结合蓖麻毒素的能力比在25℃下更强。在乳糖存在的情况下，蓖麻毒素的毒性活性完全丧失，这表明蓖麻毒素与细胞的结合是通过含有半乳糖基残基的结合位点发生的。
