Fluorescent modification for peptide sequencing by postsource decay-matrix assisted laser desorption/ionization-mass spectrometry.
The sequential analysis of a peptide of CDYEGRLI, relating to the nucleic proteins in influenza virus, was performed by the postsource decay (PSD) fragmentation method using matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). The sequence of the peptide was difficult to analyze by MALDI-MS since the PSD fragment ions of the peptide were almost never observed and were not amenable to complete sequence interpretation. The peptide was modified by 4(5)-(iodoacetamide) fluorescent reagent to improve the sensitivity of the MALDI-PSD fragment spectrum. In the spectrum of the fluorescent modified peptide, almost all sequential b-series fragment ions were observed clearly, which was sufficient for complete sequence interpretation. The results indicate the advantage of fluorescent modification for the total sequencing of the peptides by MALDI-MS.
Nakagawa
M
M
National Institute of Bioscience and Human Technology, AIST, Tsukuba, Ibaraki, Japan.
Yamagaki
T
T
Nakanishi
H
H
D005452:Fluoresceins; D005453:Fluorescence; D009975:Orthomyxoviridae / Q000737:chemistry*; D010455:Peptides / Q000032:analysis*; D020539:Sequence Analysis, Protein; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D014764:Viral Proteins / Q000032:analysis*
D005452:Fluoresceins; D010455:Peptides; D014764:Viral Proteins; C015296:5-iodoacetamidofluorescein