Binding and endocytosis of monoterbium transferrin by K562 cells  

作　　者：ZHAO Chungui1, YANG Binsheng1,2, ZHANG Wei3, BAI Haijing2 & LIU Wen2 1. Institute of Biological Technology, Shanxi University, Taiyuan 030006, China 2. Institute of Molecular Science, Shanxi University, Taiyuan 030006, China 3. Chinese Institute of Radiation Protection, Taiyuan 030006, China Correspondence should be addressed to Yang Binsheng (e-mail: [e-mail]) 

出　　处：《Chinese Science Bulletin》2003年第2期127-130,共4页

基　　金：This work was supported by the National Natural Science Foundation of China (Grant No. 20071022) and the Natural Science Foundation of Shanxi Province (Grant No. 991013).

摘　　要：Using isotopic labeling of human serumapotransferrin, the binding and the endocytosis of monoter-bium transferrin (TbC-apotransferrin, TbC-apotransferrin-FeN) by K562 cells, a human leukemic cell line, have beeninvestigated. There are about (8.58±2.41)×105 binding sites per cell surface at 0℃. The association constant for TbC-apotransferrin binding is 4.1×107 mol-1·L, for TbC-apotransferrin-FeN 2.7×107 mol-1·L at 0℃. At pH 7.4, upon warming cells to 37℃, endocytosis starts. The rate constantsfor the endocytosis are about 0.97 min-1 and 0.31 min-1 and the endocytosis ratio reaches 56% and 80% for TbC-apotransferrin and TbC-apotransferrin-FeN, respectively.Using isotopic labeling of human serumapotransferrin, the binding and the endocytosis of monoter-bium transferrin (TbC-apotransferrin, TbC-apotransferrin-FeN) by K562 cells, a human leukemic cell line, have beeninvestigated. There are about (8.58±2.41)×105 binding sites per cell surface at 0℃. The association constant for TbC-apotransferrin binding is 4.1×107 mol-1·L, for TbC-apotransferrin-FeN 2.7×107 mol-1·L at 0℃. At pH 7.4, upon warming cells to 37℃, endocytosis starts. The rate constantsfor the endocytosis are about 0.97 min-1 and 0.31 min-1 and the endocytosis ratio reaches 56% and 80% for TbC-apotransferrin and TbC-apotransferrin-FeN, respectively.

关 键 词：K562细胞 转铁蛋白 铽离子 结合 内噬作用 碘125标记 

分 类 号：R733.7[医药卫生—肿瘤]