Presentation of a homobifunctional azo-reagent for protein structure analysis by collision-induced dissociative chemical cross-linking: Proof-of-principle

- Azo-containing compound used as a CID-labile reagent for chemical cross-linking (XL).
- CID of peptide-azo-peptide ions yields N2 loss and open shell peptide product ions.
- ESI-MSn of interpeptide and intrapeptide XL demonstrates proof-of-principle.
- The distonic nature of peptide radical cations is proved by ion-molecule reactions.