Mass spectra were recorded in positive ion reflector mode on an Applied Biosystems 4700 MALDI mass spectrometer. The instrument was calibrated before each run using the 4700 Calibration Mix 1 (Applied Biosystems), and in addition, individual MS spectra were internally calibrated using tryptic autolytic peaks (if present). MSMS analysis was calibrated on the fragmentation of Glu-fibrinopeptide. For MSMS analysis, the top five most intense, non-tryptic precursors were selected for fragmentation by collision-induced dissociation. Neither base-line subtraction nor smoothing was applied to recorded spectra.