Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
In order to investigate the conformational properties of the precursor proteins of lanthionine-containing bacteriocins we synthesized the leader peptides of the pre-lantibiotics of gallidermin, epidermin, Pep5, nisin, subtilin, the C-terminal 30-mer segment of pre-cinnamycin, propeptide segments of Pep5 and gallidermin and the complete pre-gallidermin, which consists of 52 residues. The peptides were synthesized in a step-by-step synthesis by the Fmoc/tBu strategy using an optimized procedure for the synthesis of large peptides. All peptides were analyzed by HPLC and characterized by electrospray mass spectrometry and amino acid analysis. Circular dichroism spectra exhibited strong α-helical Cotton effects even at a low concentration of trifluoroethanol for all N-terminal leader peptides. Comparative investigations of the C-terminal propeptide segments led to a model of the conformation of the prepeptides of Pep5 and gallidermin in aqueous and lipophilic environments. In addition, circular dichroism investigations on the synthetic precursor protein of gallidermin and the isolated natural pre-Pep5 were performed.
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