MALDI-TOF and MALDI-TOF/TOF analysis of the N-terminal peptides of LprF. A. MS analysis of AspN-digested peptides of LprF purified from M. bovis BCG parental strain. Filled triangle, diacylglycerol (C16/C19) + N-acyl (C16) modified and glycosylated N-terminal peptide, open triangle, diacylglycerol (C16/C19) + N-acyl (C19) modified and glycosylated N-terminal peptide B. MS/MS analysis of the N-terminal peptide of LprF from M. bovis BCG parental strain. Eliminated fragments of LprF modifications are shown in the upper part of the spectrum. ➀ Tuberculostearinamide + Didehydroalanine, ➁ Diacylthioglyceryl (C16/C19), ➂ Hexose. C. Schematic drawing of the modified +1 cysteine with the cleavage sites of each identified m/z signal.