Identification of biotinylated lysine residues in the photoprotein aequorin by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry peptide mapping after lysine-specific endopeptidase digestion.
A method for identifying modified lysine residues in a protein, using lysine-specific endopeptidase treatment followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) peptide mapping, is described. As a model protein, the photoprotein aequorin was chosen and the N-hydroxysuccinimide ester of biotin was employed to chemically modify the lysine residues. After digestion with lysine-specific endopeptidase, the biotinylated residues of an amino terminus and five potential lysine residues were identified by MALDI-TOF-MS without any other separation procedure.
Inouye
Satoshi
S
Yokohama Research Center, Chisso Corp., 5-1 Okawa, Kanazawa-ku, Japan. sinouye@chisso.co.jp
Nakamura
Mitsuhiro
M
D000331:Aequorin / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D001710:Biotin / Q000737:chemistry; D010450:Endopeptidases / Q000737:chemistry* / Q000378:metabolism; D008239:Lysine / Q000032:analysis* / Q000737:chemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010449:Peptide Mapping; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D010446:Peptide Fragments; D000331:Aequorin; D001710:Biotin; D010450:Endopeptidases; C044574:lysine-C peptidase; D008239:Lysine