|
Modification of Serine/Threonine residues on peptides by phosphorylation or
addition of a single O-linked N-acetylglucosamine (O-GlcNAc) plays an important
role in cell regulation. In many instances, the sites of O-GlcNAcylation or
phosphorylation are localized to the same, or neighboring residues on the
peptide. Both modifications are extremely dynamic and labile, making them
difficult to analyze by traditional mass spectrometry fragmentation techniques
such as Collisionally Induced Dissociation (CID). In conventional CID
experiments, modifications such as these are often lost prior to fragmentation
of the peptide backbone, preventing localization of the site of modification,
although the type of modification is often identified. This makes direct
identification of sites of O-linked glycosylation almost impossible without
employing chemical derivatization techniques.
A new fragmentation technique, Electron Transfer Dissociation, or ETD,
preserves labile PTMs, enabling both PTM identification and site localization.
Learn how to utilize ETD on a linear ion trap mass spectrometer for the
detection and localization of neighboring phosphorylated and O-GlcNacylated
sites on peptides. |
0 Items 