Figure 4.

Matrix-assisted laser desorption ionization time-of-flight mass spectra of extracts of media in which the following strains were grown: (a) S. cinnamoneus cinnamoneus DSM 40005 (cinnamycin); (b) S. lividans/pOJ436; (c) S. lividans/pIJ10109 (cinnamycin); (d) S. lividans/pIJ10119 (duramycin B); (e) S. lividans/pIJ10121 (duramycin). The lantibiotic predicted to be made by the strain is given in parentheses. The masses shown are 1 Da in excess of actual masses because of the addition of a proton during ionization. Masses quoted elsewhere have been rounded up and the mass of the extra proton has been subtracted. The larger peaks to the right of the peak for duramycin B in d correspond to masses predicted for the unmodified duramycin B propeptide and its oxidized form.