Study of DNA-Protein Cross-Links Formation between Lysozyme and Oxanine by Mass Spectrometry

摘要

The modifications of lysozyme by dOxo were observed at Lys13, Lys97, and Lys1 16 out of the six lysine residues as well as at Ser85 and Ser86 out of the ten serine residues, according to the nanoLC/NSI/MS/MS analysis of the tryptic digest. The dose-response curves constructed under the SRM mode revealed a dose-dependent relationship between the concentrations of dOxo and the extents of modification at specific sites in a semi-quantitative manner. Furthermore, the sites of modifications on lysozyme are in good agreement with the solvent accessibility of the residues. Reaction of Oxa-containing DNA with lysozyme revealed modification at Lys116, Ser85, and Ser86 residues.