METHOD OF QUANTIFYING OXIDIZED PROTEIN, LABELING REAGENTS FOR QUANTIFYING OXIDIZED PROTEIN AND LABELING REAGENT KIT FOR QUANTIFYING OXIDIZED PROTEIN

摘要

An oxidized protein, which has been denatured by oxidation, is labeled with labeling reagents and quantified by mass spectrometry. In this process, a first labeling reagent, which is capable of reacting with the oxidized protein, and a second labeling reagent, which has the same chemical structure as the first labeling reagent and in which at least a part of the constituting atoms is substituted by an isotope of the atom concerned, are employed as the labeling agents. The oxidized protein labeled with the first labeling reagent and the oxidized protein labeled with the second labeling reagent are mixed together at various mixing ratios and subjected to mass spectrometry. As the labeling reagents, use is made of, for example, 2,4-dinitrophenylhydrazine and 2,4-dinitrophenylhydrazine in which a carbon atom in the phenyl group has been substituted by a stable isotope (<SUP>13</SUP>C).