Identification of radiation-induced cross-linking between thymine and tryptophan by electrospray ionization-mass spectrometry.
Upon exposure to ionizing radiation, DNA undergoes a variety of modifications including the production of a covalent bond between the nucleobase thymine and aromatic amino acids. In this work, electrospray ionization-mass spectrometry(ESI-MS) was used to identify the gamma radiation-induced covalent cross-linking of model peptides (sequence YPPW and pYPPW) with the nucleobase thymine. Tandem electrospray ionization-mass spectrometry (ESI-MSn) was employed to investigate the cross-linking sites. The results showed that irrespective of whether tyrosine was phosphorylated or not, the nucleobase thymine was cross-linked with the tryptophan residue. Possible cross-linking mechanisms are proposed by investigating the related mass peaks.
Shi
Wei-Qun
WQ
Key Laboratory of Bioorganic Phosphorous Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China.
Hu
Jia
J
Zhao
Wei
W
Su
Xiao-Yang
XY
Cai
Hui
H
Zhao
Yu-Fen
YF
Li
Yan-Mei
YM
D003432:Cross-Linking Reagents; D007202:Indicators and Reagents; D019000:Phosphotyrosine / Q000737:chemistry / Q000528:radiation effects; D021241:Spectrometry, Mass, Electrospray Ionization; D013941:Thymine / Q000737:chemistry* / Q000528:radiation effects*; D014364:Tryptophan / Q000737:chemistry* / Q000528:radiation effects*
D003432:Cross-Linking Reagents; D007202:Indicators and Reagents; D019000:Phosphotyrosine; D014364:Tryptophan; D013941:Thymine