How Symmetry Influences the Dissociation of Protonated Cyclic Peptides

Protonated cyclic dipeptides undergo collision-induced dissociation, and this reaction mechanism strongly depends on the symmetry nature of residues. We review main dissociation for a series dipeptides, obtained through chemical dynamics simulations. The systems range from symmetrical cyclo-(glycyl-glycyl), with two possible protonation sites located peptide ring, to cyclo-(tyrosyl-prolyl), where ring is broken by dissimilar different Finally, cyclo-(phenylalanyl-histidyl) shows completely asymmetric situation, proton one dipeptide side chains, which explains peculiar fragmentation induced shuttling proton, whose efficiency dependent relative chirality