Bolton A E, Lee-Own V, McLean R K, Challand G S
Clin Chem. 1979 Oct;25(10):1826-30.
We compared three different methods for radioiodination of human spleen ferritin. Tracers prepared by direct oxidative iodination with use of Chloramine T or 1,3,4,6-tetrachloro-3 alpha, 6 alpha-diphenylglycoluril (Iodogen) were structurally altered by the labeling procedure, as was made apparent by gel filtration and electrophoresis on polyacrylamide gel. Tracers prepared by conjugation to radioiodinated N-succinimidyl-6-(4-hydroxyphenyl)propionate retained their structural integrity, as assessed by physicochemical methods. Such tracers bound more than 90% in antibody excess, yielded self-displacement curves parallel to unlabeled ferritin standards, and retained their immunoreactivity for nine weeks. By contrast, immunological activity and stability of tracers prepared by the oxidative methods were less satisfactory. Tracers prepared by using lodogen were unsuitable for use in the ferritin radioimmunoassay because of shallow standard-inhibition curves and poor binding in the absence of added standard. Thus, we found the conjugation procedure to be the most suitable of the three methods for preparation of spleen-ferritin tracers.
我们比较了三种对人脾铁蛋白进行放射性碘化的不同方法。通过使用氯胺T或1,3,4,6 - 四氯 - 3α,6α - 二苯基甘脲（碘甘脲）进行直接氧化碘化制备的示踪剂，在标记过程中其结构发生了改变，这在凝胶过滤和聚丙烯酰胺凝胶电泳中表现明显。通过与放射性碘化的N - 琥珀酰亚胺基 - 6 - （4 - 羟基苯基）丙酸共轭制备的示踪剂，经物理化学方法评估，保持了其结构完整性。这类示踪剂在抗体过量时结合率超过90%，产生的自置换曲线与未标记的铁蛋白标准品平行，并且在九周内保持其免疫反应性。相比之下，通过氧化方法制备的示踪剂的免疫活性和稳定性则不太令人满意。使用碘甘脲制备的示踪剂由于标准抑制曲线较浅且在不添加标准品时结合不佳，不适用于铁蛋白放射免疫测定。因此，我们发现共轭法是三种制备脾铁蛋白示踪剂的方法中最合适的。
