An enzymic method for the trace iodination of immunoglobulins and other proteins.
An enzymic method for the trace iodination of immunoglobulins and other proteins.
复制标题
一种用于免疫球蛋白和其他蛋白质痕量碘化的酶法。
作者：
J. Marchalonis
1. 本发明描述了一种用乳过氧化物酶、过氧化氢和碘化物组成的体系对免疫球蛋白和其它血清蛋白进行微量碘化的方法。2. γ免疫球蛋白被标记为特定的放射性为5微克/马克杯。通过电泳和密度梯度超离心分析，无载流子[(125)I]碘化物没有变性的迹象。3. 胰蛋白酶水解与肽；用这种方法对一个完全特征化的放射性碘化肽进行了映射，结果表明[(125)I]碘化物与酪氨酸基残基结合。4. 通过这种方法，蛋白质对碘的易感性不同。例如，在相同条件下，人γ免疫球蛋白比人α(2)巨球蛋白更易碘化。5. 乳酸过氧化物酶比辣根过氧化物酶更容易催化蛋白质的碘化。
1. A method is described for the trace iodination of immunoglobulins and other serum proteins by a system consisting of lactoperoxidase, hydrogen peroxide and iodide. 2. gammaG immunoglobulin that had been labelled to a specific radioactivity of 5muc/mug. by use of carrier-free [(125)I]iodide gave no evidence of denaturation when analysed by electrophoresis and density-gradient ultracentrifugation. 3. Tryptic hydrolysis and peptide ;mapping' of a completely characterized peptide radioiodinated by this method showed that the [(125)I]iodide was bound to tyrosyl residues. 4. Proteins differ in their susceptibility to iodination by this method. Human gammaG immunoglobulin, for example, is iodinated more than ten times as readily as is human alpha(2)-macroglobulin under the same conditions. 5. Lactoperoxidase catalyses the iodination of proteins much more readily than does horseradish peroxidase.