title: Epidermin: sequencing of a heterodetic tetracyclic 21-peptide amide antibiotic.
abstract: Epidermin is a large peptide antibiotic, which is synthesized in the ribosome via a precursor protein, followed by enzymatic modifications. It was isolated from the culture filtrate of Staphylococcus epidermidis Tü 3298 by adsorption on Amberlite XAD-8. The basic heneicosapeptide amide was chromatographed on Sephadex LH-20 and purified to homogeneity via multiplicative counter-current distributions in one acidic and one neutral system. Tryptic digestion gave the soluble N-terminal fragment epidermin-(1-13)-peptide (P1) and the insoluble C-terminal fragment 2-oxobutyryl-epidermin-(15-21)-peptide amide (P2), each possessing two sulfide ring systems. The heterodetic rings consisted of meso-lanthionine and (2S,3S, 6R)-3-methyllanthionine (P1), meso-lanthionine and C-terminally the new amino acid S-(2-aminovinyl)-D-cysteine (P2). The complex sequence was elucidated via a combination of desulfurization with Raney nickel, enzymatic and acidolytic degradations, gas-phase sequencing, fast-atom bombardment and field-desorption mass spectrometry and NMR spectroscopy.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000302:isolation & purification; D001430:Bacteriocins; D002021:Buffers; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D006868:Hydrolysis; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000032:analysis; D010455:Peptides; D010456:Peptides, Cyclic / Q000302:isolation & purification; D013057:Spectrum Analysis; D014357:Trypsin
chemical_list: D000596:Amino Acids; D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D002021:Buffers; D010446:Peptide Fragments; D010455:Peptides; D010456:Peptides, Cyclic; C050558:epidermin; D014357:Trypsin