Figure 7: MALDI QIT ToF MS/MS spectrum of the ion signal at m/z 1240.01 (c.f Figure 6A). The determined partial amino acid sequence is depicted and was assigned to an RA33 peptide comprising amino acids 85–95. The mass spectrometric fragment ions from the Y" type ion series and the B type ion series are indicated. Loss of ammonia and loss of water, respectively, is indicated. DHB was used as a matrix.