Surface-Induced Dissociation of Multiply-Protonated Peptides.

We report here surface-induced dissociation spectra of three multiply-charged peptides doubly-protonated angiotensin I, doubly-protonated renin substrate, and triply-protonated mellitin. For comparison, the collision- activated dissociation spectra of renin substrate and mellitin are also presented. The spectra show that surface-induced dissociation provides structural information on multiply-charged peptides at sample concentrations compatible with electrospray ionization. For angiotensin I, renin substrate, and mellitin, surface collisions 100-165 eV favor a limited number of fragmentation pathways, which are the same as those favored in collision activated dissociation experiments.