Figure 4.
Representative online collisionally activated dissociation (CAD) of multipass integral membrane proteins. (a) Mass spectra of the voltage-dependent anion-selective channel protein 1 (VDAC) with fragmentation map. The protein was identified with 11 b ions and 28 y ions and with a mass accuracy of 1.3 ppm. Acetylation was localized to the N-terminus. (b) Mass spectra and fragmentation map of ADP/ATP translocase identified with 14 b ions and 32 y ions and with a mass accuracy of 1.8 ppm. One acetylation was localized to the N-terminus and the other one localized to residues 94–106. 3D protein structures were generated from the Swiss-Prot repository.56