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Updated: Jun 23, 2026

Laser-free Hydroxyl Radical Protein Footprinting to Perform Higher Order Structural Analysis of Proteins
Published on: June 4, 2021
Analysis of hydroxyl radical-induced oxidation process of glucagon by reversed-phase HPLC and ESI-MS/MS
Hideaki Ichiba1, Tomoko Ogawa, Takehiko Yajima
1Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan.
Abstract:
Structural modification of a polypeptide hormone, glucagon, by a hydroxyl radical in vitro was investigated by reversed-phase high-performance liquid chromatography (RP-HPLC), and the oxidized site of glucagon was detected by electrospray ionization tandem mass spectrometry (ESI-MS/MS). It was shown that (27)methionine (Met) was oxidized to (27)Met sulfoxide by hydroxyl radical, and the production rate of (27)Met sulfoxide was faster than that by hydrogen peroxide. In addition, production of (27)Met sulfoxide enantiomer was confirmed by RP-HPLC analysis. cAMP production in a HepG2 cell induced by (27)Met sulfoxide glucagon was reduced to approximately 75% as compared with that induced by the native form of glucagon.

