Effects of transition metal ion coordination on the collision‐induced dissociation of polyalanines

One of the challenges for sequencing peptides by MS‐MS is the interpretation of complex fragment ion patterns. Many approaches have been explored seeking to produce fragmentation patterns that are more predictable and thus easier to interpret. One of these involves the formation of a gas‐phase adduct of peptide with a metal ion which acts to preferentially activate certain fragmentation pathways. In this month's Special Feature, Prof. Carolyn Cassady and co‐workers at the University of Alabama (Tuscaloosa, AL) examine the fragmentation patterns produced from first‐row transition metal adducts of some model peptides with the goal of gaining insight into the gas‐phase chemistry of transition metal‐cationized peptides and to increase the understanding of how specific transition metal ions affect dissociation of the peptide backbone.