Modification of Cysteine Residue in Peptides by a Fluorescent Reagent for Complete Sequence Analyses Using Post-Source Decay Method in Matix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

摘要

In the sequence analyses of antigen peptides from nucleoprotein in influencza virus,it was very difficult to obtain the sufficient numbers of product ions using the post-source decay (PSD)method in MALDI-TOF-MS.Fluorescent modification of the thiol group of the cysteine residue in the target peptides using 5-iodoacetamide fluorescein was introduced for the PSD measurement.The fluorescently-labeled peptides gave sufficient product ions for complete sequence analyses in the PSD spectrum,which leads to the complete sequence analyses of the peptides with cysteine residue.