Premium
Lysozyme oxidation by singlet molecular oxygen: Peptide characterization using [ 18 O]‐labeling oxygen and nLC‐MS/MS
Author(s) -
Marques Emerson Finco,
Medeiros Marisa H.G.,
Di Mascio Paolo
Publication year - 2017
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.3983
Subject(s) - chemistry , lysozyme , mass spectrometry , histidine , biomolecule , electrospray ionization , singlet oxygen , chromatography , peptide , amino acid , tryptophan , oxygen , organic chemistry , biochemistry
Singlet molecular oxygen ( 1 O 2 ) is generated in biological systems and reacts with different biomolecules. Proteins are a major target for 1 O 2 , and His, Tyr, Met, Cys, and Trp are oxidized at physiological pH. In the present study, the modification of lysozyme protein by 1 O 2 was investigated using mass spectrometry approaches. The experimental findings showed methionine, histidine, and tryptophan oxidation. The experiments were achieved using [ 18 O]‐labeled 1 O 2 released from thermolabile endoperoxides in association with nano‐scale liquid chromatography coupled to electrospray ionization mass spectrometry. The structural characterization by nLC‐MS/MS of the amino acids in the tryptic peptides of the proteins showed addition of [ 18 O]‐labeling atoms in different amino acids.