Table 1

Masses of cysteine-containing tryptic peptides of Keap1 modified by reaction with Dex-mes and detected by matrix-assisted laser desorption ionization/time-of-flight mass spectrometry

  • Dex-mes labeled cysteine residues (C257, C273, C288, and C297) of Keap1 are located in the intervening region (IVR, between the BTB and double glycine or Kelch repeat domains) and close (C613) to the C-terminal domain. The identity of peptides 22–23 and 27–28 was confirmed by liquid chromatography tandem mass spectrometry coupled with electrospray ionization and fragmentation by collision-induced dissociation.