Miyazaki H, Beppu M, Terao T, Osawa T
Gan. 1980 Dec;71(6):766-74.
As a model experiment for the preparation of cancer chemotherapeutic agents, a disulfide-linked conjugate of rabbit anti-mouse IgG (RaMIgG) and ricin A-cahin was synthesized. Activated sulfhydryl groups were first introduced into RaMIgG and then the modified RaMIgG was reacted with ricin A-chain. The fraction containing the conjugate was obtained from the reaction mixture by gel filtration through Sephadex G-150 and was characterized by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis and double immunodiffusion in agar. The inhibitory activity of A-chain against protein synthesis in a cell-free system and the binding activity of RaMIgG to mouse B lymphocytes were both fully retained. The purified conjugate selectively inhibited protein synthesis in mouse B lymphocytes possessing cell surface Ig, but not that in thymocytes. The cytotoxicity was inhibited by adding mouse IgG and an excess amount of RaMIgG to the cell culture. The effects of unlinked RaMIgG and A-chain on the cytotoxicity were negligible even when the two were used as a mixture.
作为制备癌症化疗药物的模型实验，合成了兔抗小鼠IgG（RaMIgG）与蓖麻毒蛋白A链通过二硫键连接的偶联物。首先将活化的巯基引入RaMIgG，然后使修饰后的RaMIgG与蓖麻毒蛋白A链反应。通过Sephadex G - 150凝胶过滤从反应混合物中获得含有偶联物的组分，并通过十二烷基硫酸钠 - 聚丙烯酰胺圆盘凝胶电泳和琼脂双向免疫扩散进行表征。A链在无细胞系统中对蛋白质合成的抑制活性以及RaMIgG与小鼠B淋巴细胞的结合活性均得以完全保留。纯化的偶联物选择性地抑制具有细胞表面Ig的小鼠B淋巴细胞中的蛋白质合成，但不抑制胸腺细胞中的蛋白质合成。通过向细胞培养物中加入小鼠IgG和过量的RaMIgG可抑制细胞毒性。即使将未连接的RaMIgG和A链混合使用，它们对细胞毒性的影响也可忽略不计。
