Peptides complexed to cydodextrin fragment rather than dissociate when subjected to blackbody infrared radiation

Blackbody infrared radiation dissociation is used to probe the fragmentation behavior of peptide-cyclodextrin complexes. Complexes formed by combining bradykinin (and some of its analogues) with permethylated β-cyclodextrin undergo peptide fragmentation father than complex dissociation under these conditions. Activation energies and preexponential factors are obtained from Arrhenius plots constructed over a temperature range (between 323 and 440 K). The fragmentation behavior of the peptides does not differ considerably when the sites of inclusions are removed from the peptide. Molecular dynamics simulations are pa formed to better understand the experimental observations.