The tetracyclic lantibiotic actagardine. 1H-NMR and 13C-NMR assignments and revised primary structure.
The primary structure of the peptide lantibiotic actagardine was determined in (2H3)acetonitrile/H2O by homonuclear two- and three-dimensional NMR spectroscopy as well as 2D 1H(13C) correlation spectra at natural abundance. Actagardine was found to be a tetracyclic 19-residue peptide containing one lanthionine and three overlapping beta-methyllanthionine bridges. Sequential resonance assignment and location of the four thioether rings was accomplished by 2D NOESY, 3D NOESY-TOCSY and gradient-enhanced 1H(13C)-HMBC spectra. The C-terminal thioether bridge was shown to be oxidized to a sulfoxide. The NMR data were additionally confirmed by mass spectrometry and Edman degradation after chemical modification, which allowed sequencing of lanthionine and beta-methyllanthionine residues. Our studies clearly show, that the structure of actagardine as previously published by Kettenring et al. (1990) J. Antibiot. 43, 1082-1088 is not correct.
Zimmermann
N
N
Institut für Organische Chemie, Universität Tübingen, Germany.
Metzger
J W
JW
Jung
G
G
D000409:Alanine / Q000031:analogs & derivatives / Q000737:chemistry; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001430:Bacteriocins; D002247:Carbon Isotopes; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D010455:Peptides; D011522:Protons; D013440:Sulfides
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D002247:Carbon Isotopes; D010455:Peptides; D011522:Protons; D013440:Sulfides; C005080:beta-methyllanthionine; C012993:gardimycin; C001520:lanthionine; D000409:Alanine