Radical-Initiated Photodissociation at Tryptophan Residues within Intact Proteins in the Gas Phase.

ABSTRACT: Controlling selective fragmentation at particular residues in the gas phase could greatly improve our ability to characterize intact proteins by mass spectrometry and reveal proteoforms crucial to human biology. However, the chemical homogeneity and size of proteins frustrates characterization because fragmentation inevitably leads to thousands of product ions and highly complex spectra that resist complete interpretation. Herein, we report a method for the selective, photochemical cleavage of whole proteins in the gas phase via the photolysis of alpha-peptidyl radicals. The activation process results in predictable and selective dissociation of the peptide bond N-terminal to the initiating radical. Alpha peptidyl radicals are readily introduced in a residue specific manner via the nitrosa

SUBMITTER: He L 

PROVIDER: S-EPMC12653345 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature