Oxidation of feric-cytochrome c by N,N′-bis(2-hydroperoxy-2-methoxyethyl)-1,4,5,8-naphthalene tetracarboxylic diimide, NP III -: Site specific modification of cytochrome c

When the synthetic hydroxyl radical generator, N,N'-bis (2-Hydroperoxy-2-methoxyethyl)-1,4,5,8-naphthalene-tetracarboxylic diimide, NP III, was photoirradiated in the presence of ferric-cytochrome c (Fe3+), the fragmentation peak corresponding to the specific oxidative modification at the histidine site of cytochrome c was observed in the Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectroscopy (MALDI-TOF) measurement.. Without photoirradiation, no such protein oxidation was observed in the experimental conditions employed. This result suggests the possible usage of NP-III as an oxidative protein-modifying reagent.