Figure 7. Mass spectrometry analysis after in-solution digestion of the protein BmrA.

The purified protein BmrA (10 µM) was digested using trypsin in the solution containing 0.05% DDM, 50 mM NaCl, 50 mM Tris/HCl pH 8, 10% glycerol and 5 mM beta-mercaptoethanol. The mixture was investigated by mass spectrometry in ESI or APPI under dopant assisted conditions using toluene and 9 eV photons. The precursor ion m/z 1198.75 corresponding to the first transmembrane domain is labelled with a black arrow.