Leclerc G, Goulard C, Prigent Y, Bodo B, Wróblewski H, Rebuffat S
Laboratoire de Chimie des Substances Naturelles, ESA 8041 CNRS, GDR 790 CNRS, IFR 63 CNRS-INSERM, Muséum National d'Histoire Naturelle, 63 Rue Buffon, 75231 Paris, France.
J Nat Prod. 2001 Feb;64(2):164-70. doi: 10.1021/np000240s.
Longibrachins are members of the class of natural Aib-containing peptides designated as peptaibols. Six longibrachins, LGA I-IV and LGB II and III, were purified from a Trichoderma longibrachiatum strain by a procedure employing several chromatography steps including reversed-phase HPLC. The amino acid sequence determination was based on a combination of liquid secondary ion mass spectrometry (LSIMS) and two-dimensional 1H and 13C NMR spectroscopy. Longibrachins are 20-residue peptaibols with a C-terminal phenylalaninol and either neutral (LGA; Gln18) or acidic (LGB; Glu18) character. Longibrachins LGB II and III have novel sequences. Both longibrachins LGA and LGB show significant bactericidal activity against mycoplasmas (Acholeplasma, Mycoplasma, and Spiroplasma), with minimal inhibitory concentrations in the range 1.56-12.5 microM (3-25 micrograms/mL), and also perturb the permeability of membrane bilayers. Longibrachin LGA IV is the most potent of the presently known 18-20-residue peptaibols. The antimicrobial and membrane-perturbing properties of longibrachins, which are described here for the first time, were shown to be correlated.
