Choi Y S, Lee M S, Rosenspire A J
Mol Immunol. 1983 Dec;20(12):1249-57. doi: 10.1016/0161-5890(83)90153-0.
Antigen-binding receptor (ABR) molecules have been selectively radiolabeled and isolated from immunized chicken spleen cells. The specific radiolabeling of the receptors has been accomplished by utilizing a novel technique employing lactoperoxidase (LPO) covalently linked to antigen (Ag) for which human gammaglobulin was used. The cell surface ABRs were first bound to the Ag-LPO conjugates through specific recognition sites on the Ag portion of the conjugates. The bound LPO portions were then allowed to catalyze the radioiodination of the ABRs. After radiolabeling, cells were solubilized with detergents. ABRs still bound to Ag-LPO conjugates were directly isolated from the lysates via immunoaffinity chromatography utilizing an immunoaffinity reagent directed toward the antigen portion of the ABR-Ag-LPO complex. The radioactive materials isolated in this way were then analyzed via SDS-PAGE under reducing conditions. It appears that as expected, most of the specifically-labeled and isolated materials were immunoglobulin (Ig). Both the membrane-bound form of the heavy chain (mol. wt 77 K) as well as the secreted form (mol. wt 67 K) were detected, along with the light chain (mol. wt 25 K). An additional polypeptide of mol. wt 55 K was also selectively labeled and isolated along with the Ig. This may be a molecule closely associated with the membrane immunoglobulin on B-cell surface.
抗原结合受体（ABR）分子已从免疫鸡脾细胞中被选择性地放射性标记并分离出来。受体的特异性放射性标记是通过一种新技术实现的，该技术利用与抗原（Ag）共价连接的乳过氧化物酶（LPO），其中使用了人丙种球蛋白作为抗原。细胞表面的ABR首先通过共轭物Ag部分上的特异性识别位点与Ag-LPO共轭物结合。然后让结合的LPO部分催化ABR的放射性碘化。放射性标记后，用去污剂溶解细胞。仍与Ag-LPO共轭物结合的ABR通过免疫亲和色谱法直接从裂解物中分离出来，该免疫亲和色谱法使用针对ABR-Ag-LPO复合物抗原部分的免疫亲和试剂。然后在还原条件下通过SDS-PAGE分析以这种方式分离的放射性物质。正如预期的那样，似乎大多数特异性标记和分离的物质都是免疫球蛋白（Ig）。检测到了重链的膜结合形式（分子量77K）以及分泌形式（分子量67K），还有轻链（分子量25K）。一种分子量为55K的额外多肽也与Ig一起被选择性地标记和分离出来。这可能是一种与B细胞表面膜免疫球蛋白密切相关的分子。
