Energetics and dynamics of dissociation of deprotonated peptides: Fragmentation of angiotensin analogs

► We examined energy and entropy effects in dissociation of deprotonated peptides using surface-induced dissociation combined with RRKM modeling. ► Relative stability of peptides towards fragmentation is very different for protonated and deprotonated species. ► Fragmentation of acidic peptides is associated with very low threshold energy and tight transition state. ► Charge-remote fragmentation is observed for low-energy pathways of the basic RVYIHPF peptide. ► Backbone fragmentation is characterized by fairly high energy barrier.