Mackenzie I L, Donaldson R M, Schilling R F
J Clin Invest. 1969 Mar;48(3):516-24. doi: 10.1172/JCI106009.
Human intrinsic factor (IF) saturated with (60)Co-labeled cyanocobalamin ((60)CoB(12)) was purified and then iodinated with (125)I to yield (125)I-labeled IF-(60)CoB(12) preparations of high specific activity. Sephadex G200 and DEAE-cellulose chromatography of the iodinated IF-(60)CoB(12) complex showed coincidence of the major (125)I and the (60)Co radioactivity peaks. During starch-gel electrophoresis (60)Co radioactivity from noniodinated and iodinated complexes migrated to the same extent while (125)I radioactivity from the iodinated complex migrated slightly further anodally than did the (60)Co radioactivity. After the iodinated complex was mixed with antibody to the IF-B(12) complex (antibody II) the (125)I and (60)Co radioactivity were: (a) precipitated in similar amounts by antiglobulin serum. (b) eluted coincidentally in the 19S region on Sephadex G200, and (c) excluded to the same extent from starch gel during electrophoresis. After equilibrium exchange of IF "blocking" antibody (antibody I) for (60)Co-vitamin B(12) on (125)I-labeled IF. (125)I radioactivity from the IF-antibody I complex: (a) was precipitated by antiglobulin serum, (b) was eluated in the 19S region on Sephadex G200 gel filtration, and (c) migrated slowly towards the anode on starch-gel electrophoresis. Urinary excretion of (60)Co radioactivity in pernicious anemia patients after oral administration of (60)Co-vitamin B(12) bound to freshly prepared (125)I-labeled IF was similar to that obtained with noniodinated intrinsic factor. These results show that iodination of IF-(60)CoB(12) complex does not markedly alter the chromatographic, electrophoretic, antigenic, or absorption-promoting properties of IF.
将与（60）钴标记的氰钴胺（（60）CoB12）饱和的人内因子（IF）纯化，然后用（125）I进行碘化，以产生高比活性的（125）I标记的IF - （60）CoB12制剂。对碘化的IF - （60）CoB12复合物进行葡聚糖G200和DEAE - 纤维素色谱分析，结果显示主要的（125）I和（60）Co放射性峰重合。在淀粉凝胶电泳过程中，未碘化和碘化复合物的（60）Co放射性迁移程度相同，而碘化复合物的（125）I放射性比（60）Co放射性在阳极方向上迁移得稍远一些。将碘化复合物与IF - B12复合物抗体（抗体II）混合后，（125）I和（60）Co放射性：（a）被抗球蛋白血清以相似的量沉淀；（b）在葡聚糖G200上于19S区域同时洗脱；（c）在电泳过程中从淀粉凝胶中被排除的程度相同。在（125）I标记的IF上用IF“封闭”抗体（抗体I）与（60）Co - 维生素B12进行平衡交换后，IF - 抗体I复合物的（125）I放射性：（a）被抗球蛋白血清沉淀；（b）在葡聚糖G200凝胶过滤中于19S区域洗脱；（c）在淀粉凝胶电泳中缓慢向阳极迁移。恶性贫血患者口服与新制备的（125）I标记的IF结合的（60）Co - 维生素B12后，（60）Co放射性的尿排泄量与未碘化内因子的情况相似。这些结果表明，IF - （60）CoB12复合物的碘化不会显著改变IF的色谱、电泳、抗原或促进吸收的特性。
