Figure 2.
(a) Isolation spectrum of the [ac-AAA+AK+H]+ complex ions. The MS/MS spectra of [ac-AAA+AK+H]+ obtained by (b) CID and (c) 157 nm irradiation are shown. Product ions from the [AK+H]+ and [ac-AAA+H]+ are highlighted in red and blue, respectively. # indicates the loss of water. (d) The CID Spectrum of the water-loss product (M#) in spectrum c. Peaks are assigned according to the peptide sequence; ac-AAAAK. Within experimental uncertainty, this spectrum is indistinguishable from CID spectra obtained for ESI generated [ac-AAAAK+H]+, where the precursor ac-AAAAK peptide (here, used as a standard) was produced by solid-phase synthesis.
