Kamio M, Arima N, Tsudo M, Imada K, Ohkuma M, Uchiyama T
First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.
Biochem Biophys Res Commun. 1992 May 15;184(3):1288-92. doi: 10.1016/s0006-291x(05)80022-1.
It is known that the affinity cross-linking study of the human high-affinity Interleukin 2 (IL-2) receptor reveals triplet bands consisting of 70 kDa alpha chain(Tac)-IL-2 and the 90/80 kDa doublet. We found the cell lines lacking the lower band of the doublet in spite of the expression of both alpha and beta chains. No IL-2 binding was detectable in the presence of anti-Tac antibody in these cells. Immunoprecipitation from the cell extract of [125 I] IL-2-cross-linked T cells with anti-beta chain polyclonal IgG detected the upper band, but not lower band of the doublet. These data suggest that the lower band of the doublet represents an unknown IL-2-binding protein (p65) distinct from the beta chain and this molecule may be involved in the intermediate-affinity IL-2 binding together with the beta chain.
已知人类高亲和力白细胞介素2（IL-2）受体的亲和交联研究揭示了由70 kDaα链（Tac）-IL-2和90/80 kDa双峰组成的三重带。我们发现尽管α链和β链都有表达，但细胞系中双峰的较低条带缺失。在这些细胞中，存在抗Tac抗体时未检测到IL-2结合。用抗β链多克隆IgG从[125I]IL-2交联的T细胞的细胞提取物中进行免疫沉淀，检测到双峰的上部条带，但未检测到下部条带。这些数据表明，双峰的下部条带代表一种不同于β链的未知IL-2结合蛋白（p65），并且该分子可能与β链一起参与中等亲和力的IL-2结合。
