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.
Department of Organic Chemistry and Biochemistry, Federico II University of Naples, Naples, Italy. angamor@unina.it
Angela
A
Amoresano
Gianluca
G
Monti
Claudia
C
Cirulli
Gennaro
G
Marino
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