Cuppoletti J, Goldinger J, Kang B, Jo I, Berenski C, Jung C Y
J Biol Chem. 1985 Dec 15;260(29):15714-7.
The in situ state of assembly of the human erythrocyte anion carrier (band 3) has been investigated by applying target size analysis on the radiation-induced inactivation of anion flux and degradation of polypeptide band 3. Irradiation with a high energy electron beam resulted in inactivation of carrier-mediated anion flux in intact cells, in inside-out vesicles devoid of cytoskeletal and cytoplasmic proteins, and in inside-out vesicles whose band 3 protein has been partially proteolyzed, with little change in leak pathway. The inactivation showed a single exponential function of radiation dose from which the target size of the anion carrier was estimated to be 210,000, 220,000, and 98,000 daltons in intact cells, in the inside-out vesicles, and in the vesicles after a limited proteolysis, respectively. Irradiation also resulted in degradation of the band 3 of the inside-out vesicles, as detected on sodium dodecyl sulfate-gel electrophoresis, with a dose dependence characteristic of a target size of 220,000 daltons. It is suggested that the human erythrocyte anion carrier exists in situ as a dimer of band 3.
通过对辐射诱导的阴离子通量失活和多肽带3降解进行靶标大小分析，研究了人类红细胞阴离子载体（带3）的原位组装状态。用高能电子束辐照完整细胞、不含细胞骨架和细胞质蛋白的内翻囊泡以及带3蛋白已被部分蛋白酶解的内翻囊泡，导致载体介导的阴离子通量失活，而渗漏途径变化不大。失活呈现出辐射剂量的单指数函数，据此估计完整细胞、内翻囊泡以及有限蛋白酶解后的囊泡中阴离子载体的靶标大小分别为210,000、220,000和98,000道尔顿。如在十二烷基硫酸钠凝胶电泳上检测到的那样，辐照还导致内翻囊泡的带3降解，其剂量依赖性特征表明靶标大小为220,000道尔顿。提示人类红细胞阴离子载体原位以带3的二聚体形式存在。
