213 nm Ultraviolet Photodissociation on Peptide Anions: Radical-Directed Fragmentation Patterns

Abstract : Characterization of acidic peptides and proteins is greatly hindered due to lack of suitable analytical techniques. Here we present the implementation of 213 nm ultraviolet photodissociation (UVPD) in high-resolution quadrupole-Orbitrap mass spectrometer in negative polarity for peptide anions. Radical-driven backbone fragmentation provides 22 distinctive fragment ion types, achieving the complete sequence coverage for all reported peptides. Hydrogen-deficient radical anion not only promotes the cleavage of C-alpha-C bond but also stimulates the breaking of N-C-alpha and C-N bonds. Radical-directed loss of small molecules and specific side chain of amino acids are detected in these experiments. Radical containing side chain of amino acids (Tyr, Ser, Thr, and Asp) may possibly support the N-C-alpha backbone fragmentation. Proline comprising peptides exhibit the unusual fragment ions similar to reported earlier. Interestingly, basic amino acids such as Arg and Lys also stimulated the formation of abundant b and y ions of the related peptide anions. Loss of hydrogen atom from the charge-reduced radical anion and fragment ions are rationalized by time-dependent density functional theory (TDDFT) calculation, locating the potential energy surface (PES) of pi pi* and repulsive pi sigma* excited states of a model amide system.
Liste complète des métadonnées

Contributor : Agnès Bussy <>
Submitted on : Thursday, August 25, 2016 - 1:43:15 PM
Last modification on : Thursday, March 15, 2018 - 10:30:28 AM

Links full text




Mohammad A Halim, Marion Girod, Luke Macaleese, Jérôme Lemoine, Rodolphe Antoine, et al.. 213 nm Ultraviolet Photodissociation on Peptide Anions: Radical-Directed Fragmentation Patterns. Journal of The American Society for Mass Spectrometry, Springer Verlag (Germany), 2016, 27 (3), pp.474-486. ⟨10.1007/s13361-015-1297-5⟩. ⟨hal-01356287⟩



Record views