神经肽类激素的混合碘标记方法

125 I LABELLING OF MULTIPLE PEPTIDE HORMONES

介绍一种快速的混合碘标记肽类激素的方法，供放射免疫测定研究鱼类神经肽激素的生殖生理过程。四种神经肽激素可同时被１２５Ｉ标记，选用不同的极性溶液逐一从一种反相极性色层柱（ＳＥＰ－ＰＡＫＣ１８）上分离。利用这种混合碘标记法，不论在肽的产率、比活度或免疫活性方面，均不亚于用单个肽标记法取得的结果。

Four peptide hormones, namely mammalian gonadotropin releasing hormone (GnRH) prohormone fragment (5-16), chicken GnRH Ⅱ, salmon GnRH and neuropeptide Y are concurrently radiolabelled with 125 I in a single iodination reaction. Iodinated peptides are separated by reverse phase liquid chromatography using the SEP PAK C 18 cartridge with stepwise gradients of acetonitrile/trifluoroacetic acid as mobile phase. The quantitative yield and quality of the iodinated peptides generated in this multiple peptides iodination procedure are tested with respect to their application as a tracer in specific radioimmunoassays. The results show that the total yield of radiolabelling, the specific activity and the immunospecificity of the 125 I peptides generated in this procedure are comparable to those of the radiolabelled peptides obtained by separate iodination reactions.