A phosphohistidine proteomics strategy based on elucidation of a unique gas-phase phosphopeptide fragmentation mechanism.

ABSTRACT: Protein histidine phosphorylation is increasingly recognized as a critical posttranslational modification (PTM) in central metabolism and cell signaling. Still, the detection of phosphohistidine (pHis) in the proteome has remained difficult due to the scarcity of tools to enrich and identify this labile PTM. To address this, we report the first global proteomic analysis of pHis proteins, combining selective immunoenrichment of pHis peptides and a bioinformatic strategy based on mechanistic insight into pHis peptide gas-phase fragmentation during LC-MS/MS. We show that collision-induced dissociation (CID) of pHis peptides produces prominent characteristic neutral losses of 98, 80, and 116 Da. Using isotopic labeling studies, we also demonstrate that the 98 Da neutral loss occurs via gas-pha

SUBMITTER: Oslund RC 

PROVIDER: S-EPMC4183637 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature