TitleCharacterization and Identification of Dityrosine Cross-Linked Peptides Using Tandem Mass Spectrometry.
Publication TypeJournal Article
Year of Publication2017
AuthorsMukherjee S, Kapp EA, Lothian A, Roberts AM, Vasil'ev YV, Boughton BA, Barnham KJ, W Kok M, Hutton CA, Masters CL, Bush AI, Beckman JS, Dey SGhosh, Roberts BR
JournalAnal Chem
Date Published2017 06 06
KeywordsCross-Linking Reagents, Peptides, Tandem Mass Spectrometry, Tyrosine

The use of mass spectrometry coupled with chemical cross-linking of proteins has become a powerful tool for proteins structure and interactions studies. Unlike structural analysis of proteins using chemical reagents specific for lysine or cysteine residues, identification of gas-phase fragmentation patterns of endogenous dityrosine cross-linked peptides have not been investigated. Dityrosine cross-linking in proteins and peptides are clinical markers of oxidative stress, aging, and neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. In this study, we investigated and characterized the fragmentation pattern of a synthetically prepared dityrosine cross-linked dimer of Aβ(1-16) using ESI tandem mass spectrometry. We then detailed the fragmentation pattern of dityrosine cross-linked Aβ(1-16), using collision induced dissociation (CID), higher-energy collision induced dissociation (HCD), electron transfer dissociation (ETD), and electron capture dissociation (ECD). Application of these generic fragmentation rules of dityrosine cross-linked peptides allowed for the identification of dityrosine cross-links in peptides of Aβ and α-synuclein generated in vitro by enzymatic peroxidation. We report, for the first time, the dityrosine cross-linked residues in human hemoglobin and α-synuclein under oxidative conditions. Together these tools open up the potential for automated analysis of this naturally occurring post-translation modification in neurodegenerative diseases as well as other pathological conditions.

Alternate JournalAnal. Chem.
PubMed ID28453255