[Sulfonation modification-assisted enrichment and identification of histidine-containing peptides by strong cation exchange chromatography and mass spectrometry].
By the sulfonation at the N-terminal of peptides, the charge state of histidine-containing peptides is different from that of other peptides in pH < 3.0 solution. Based on this difference, a new method was developed to isolate and identify sulfonated histidine-containing peptides from tryptic digest of proteins by strong cation exchange (SCX) chromatography and matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF MS/MS). Using the standard proteins containing histidines as the model, the methodology was evaluated. The results show that sulfonated histidine-containing peptides were efficiently enriched by SCX, and the N-terminal sulfonation of the peptides simplifies the interpretation of the acquired mass spectra and facilitates the sequencing of histidine-containing peptides by producing consecutive and predominant ions in positive mode MS2 spectra, which is thought to be the result of the charge neutralization of b ions by the N-terminal sulfonic acid group. The discrimination of b ions and y ions can greatly enhance the confidence in peptide and subsequent protein identification. It is feasible to isolate and enrich the histidine-containing peptides by using this method which has the potential applications in proteomics.
Cao
Dong
D
Beijing Institute of Technology, Beijing 100081, China.
Zhou
Chunxi
C
Zhang
Yangjun
Y
Han
Chunguang
C
Deng
Yulin
Y
Qian
Xiaohong
X
D002411:Cation Exchange Resins / Q000737:chemistry*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D006639:Histidine / Q000032:analysis / Q000737:chemistry*; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013450:Sulfones / Q000737:chemistry
D002411:Cation Exchange Resins; D010446:Peptide Fragments; D011506:Proteins; D013450:Sulfones; D006639:Histidine