Serine, threonine of post-translational modification analysis for labeling agent

Pyrazolone derivatives glycoproteins and / or glycopeptides is analyte, isoxazolones derivatives, hydantoin derivatives, rhodanine derivatives, heated with a basic solution under conditions with maleimide derivatives, cutting the post-translational modification group, and label and analyze by, it is possible to analyze the post-translational modification of serine and / or threonine residues.