The effects of FEL irradiation against a phosphorylated peptide and the infrared spectrographic identification method for a phosphate group

Phosphorylation and dephosphorylation, which are the most remarkable post-translational modifications, are considered to be important chemical reactions that control the activation of proteins. First, we examine the phosphorylation analysis method by measuring the infrared absorption peak of the phosphate group that is observed at about 1070 cm−1 (9.4 μm) with Fourier Transform–Infrared Spectrometer (FT–IR). Next, we attempt to control the quantity of phosphorylation, that is to say an action like dephosphorylation without enzyme reactions, by irradiating 9.4 μm-Free Electron Laser (9.4 μm-FEL). FEL irradiation has an effect of some kind on the organization of infrared absorption of a phosphate group. We would now like to go on to develop this photochemical reaction like dephosphorylation by examining under several conditions and in detail.