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Membrane structure and interactions of a short Lycotoxin I analogue
Author(s) -
Adão R.,
Seixas R.,
Gomes P.,
Pessoa J. Costa,
Bastos M.
Publication year - 2008
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/psc.993
Subject(s) - isothermal titration calorimetry , isothermal microcalorimetry , peptide , chemistry , membrane , liposome , biochemistry , biophysics , biology , physics , quantum mechanics , enthalpy
Lycotoxin I and Lycotoxin II are natural anti‐microbial peptides that were identified in the venom of the Wolf Spider Lycosa carolinensis . These peptides were found to be potent growth inhibitors for bacteria ( Escherichia coli ) and yeast ( Candida glabrata ) at micromolar concentrations. Recently, shortened analogues of LycoI and LycoII have been reported to have decreased haemolytic effects. A shorter Lyco‐I analogue studied, LycoI 1–15 (H‐IWLTALKFLGKHAAK‐NH 2 ), was active only above 10 µ M , but was also the least haemolytic. On the basis of these findings, we became interested in obtaining a deeper insight into the membrane activity of LycoI 1–15, as this peptide may represent the first major step for the future development of selective, i.e. non‐haemolytic, Lycotoxin‐based antibiotics. The interaction of this peptide with liposomes of different composition was studied by microcalorimetry [differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC)] and CD. The results obtained from the calorimetric and spectroscopic techniques were jointly discussed in an attempt to further understand the interaction of this peptide with model membranes. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.