Shattering During Surface-Induced Dissociation: An Examination of Peptide Size and Structure

We present the results of direct dynamics simulations of surface-induced dissociation for A_nK, KA_n (n = 1, 3, and 5), AcA₇K, and AcKA₇ for collisions with a fluorinated self-assembled monolayer surface. Our focus is on elucidating shattering fragmentation events, which takes place in coincidence with the collision event and frequently occurs in a charge remote fashion. Shattering events typically generate a large number of fragmentation products, and hence, are not easily understood through chemical intuition. Our simulations show distinct differences between the A_nK/AcA₇K and KA_n/AcKA₇ series of peptides, with the former being more reactive, while the latter is more selective regarding the type of bond that will break. In addition, we examine the possible backbone rearrangements seen as well as sidechain fragmentation.