Gokce A, Nakamura R M, Tubis M, Wolf W
Int J Nucl Med Biol. 1982;9(2):85-95. doi: 10.1016/0047-0740(82)90034-1.
A method has been developed to achieve rapid and reproducible complexation of indium to transferrin at pH 7.4. The system consists of nitrilotriacetic acid (NTA) as the intermediate carrier ligand, whose function is to allow the 113m In ion, in a solution in Tris buffer, pH 7.4, to be transferred rapidly to the specific binding sites on transferrin. Just as in the case of iron, this complexation requires the presence of a synergistic ion such as bicarbonate. The present system can be used to allow the binding of 113mIn to transferrin when coupled to an antibody. This method has been tested by studying the conjugation of an antibody, the IgG fraction of goat anti-rabbit-IgG, with either transferrin or desferoxamine, using glutaraldehyde as the coupling agent. Optimization in terms of total protein concentration and glutaraldehyde levels lead to products where the specific metal binding capacity of the transferrin moiety remains unchanged, and where the antibody retains 70% of its antigenic activity. The present system can be considered an extension of the ELISA techniques and can be used to determine, by a terminal 113mIn labeling technique, the level of specific binding of an antibody to its antigen.
已开发出一种方法，可在pH 7.4条件下实现铟与转铁蛋白的快速且可重复的络合。该体系由次氮基三乙酸（NTA）作为中间载体配体组成，其作用是使处于pH 7.4的Tris缓冲液溶液中的113mIn离子快速转移至转铁蛋白上的特异性结合位点。正如铁的情况一样，这种络合需要协同离子如碳酸氢盐的存在。当与抗体偶联时，本体系可用于使113mIn与转铁蛋白结合。通过研究抗体（山羊抗兔IgG的IgG组分）与转铁蛋白或去铁胺的偶联，以戊二醛作为偶联剂，对该方法进行了测试。在总蛋白浓度和戊二醛水平方面进行优化后，得到的产物中转铁蛋白部分的特异性金属结合能力保持不变，且抗体保留其70%的抗原活性。本体系可被视为酶联免疫吸附测定（ELISA）技术的扩展，并且可通过末端113mIn标记技术用于确定抗体与其抗原的特异性结合水平。
