Journal article

Selective identification and quantitative analysis of methionine containing peptides by charge derivatization and tandem mass spectrometry

GE Reid, KD Roberts, RJ Simpson, RAJ O'Hair

Journal of the American Society for Mass Spectrometry | AMER CHEMICAL SOC | Published : 2005


To enable the development of a tandem mass spectrometry (MS/MS) based methodology for selective protein identification and differential quantitative analysis, a novel derivatization strategy is proposed, based on the formation of a "fixed-charge" sulfonium ion on the side-chain of a methionine amino acid residue contained within a protein or peptide of interest. The gas-phase fragmentation behavior of these side chain fixed charge sulfonium ion containing peptides is observed to result in exclusive loss of the derivatized side chain and the formation of a single characteristic product ion, independently of charge state or amino acid composition. Thus, fixed charge containing peptide ions may..

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