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Singlet oxygen‐induced protein aggregation: Lysozyme crosslink formation and nLC‐MS/MS characterization
Author(s) -
Marques Emerson Finco,
Medeiros Marisa H.G.,
Di Mascio Paolo
Publication year - 2019
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.4448
Subject(s) - chemistry , lysozyme , singlet oxygen , tryptophan , mass spectrometry , electrospray ionization , lysine , covalent bond , histidine , chromatography , thermolabile , amino acid , photochemistry , oxygen , organic chemistry , biochemistry , enzyme
Singlet molecular oxygen ( 1 O 2 ) has been associated with a number of physiological processes. Despite the recognized importance of 1 O 2 ‐mediated protein modifications, little is known about the role of this oxidant in crosslink formation and protein aggregation. Thus, using lysozyme as a model, the present study sought to investigate the involvement of 1 O 2 in crosslink formation. Lysozyme was photochemically oxidized in the presence of rose bengal or chemically oxidized using [ 18 O]‐labeled 1 O 2 released from thermolabile endoperoxides. It was concluded that both 1 O 2 generating systems induce lysozyme crosslinking and aggregation. Using SDS‐PAGE and nano‐scale liquid chromatography coupled to electrospray ionization mass spectrometry, the results clearly demonstrated that 1 O 2 is directly involved in the formation of covalent crosslinks involving the amino acids histidine, lysine, and tryptophan.