Selective detection and identification of phosphopeptides by dansyl MS/MS/MS fragmentation.
Protein phosphorylation regulates many cellular processes and pathways, such as cell cycle progression, signal transduction cascades and gene expression. Selective detection of phosphopeptides from proteolytic digests is a challenging and highly relevant task in many proteomics applications. Often phosphopeptides are present in small amounts and need selective isolation or enrichment before identification. Here we report a novel approach to label selectively phospho-Ser/-Thr residues by exploiting the features of a novel linear ion trap mass spectrometer. Using dansyl labelling and MS3 fragmentation, we developed a method useful for the large-scale proteomic profiling of phosphorylation sites. The new residues in the sequence were stable and easily identifiable under general conditions for tandem mass spectrometric sequencing.
Amoresano
Angela
A
Department of Organic Chemistry and Biochemistry, Federico II University of Naples, Naples, Italy. angamor@unina.it
Monti
Gianluca
G
Cirulli
Claudia
C
Marino
Gennaro
G
D002364:Caseins / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003543:Cysteamine / Q000737:chemistry; D003619:Dansyl Compounds / Q000032:analysis*; D006031:Glycosylation; D006868:Hydrolysis; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D010748:Phosphopeptides / Q000032:analysis*; D010766:Phosphorylation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000737:chemistry
D002364:Caseins; D003619:Dansyl Compounds; D007202:Indicators and Reagents; D010748:Phosphopeptides; D003543:Cysteamine; D014357:Trypsin