Structure-function characterization and optimization of a plant-derived antibacterial peptide.

Détails

ID Serval
serval:BIB_84A7DD08EC24
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Structure-function characterization and optimization of a plant-derived antibacterial peptide.
Périodique
Antimicrobial Agents and Chemotherapy
Auteur(s)
Suarez M., Haenni M., Canarelli S., Fisch F., Chodanowski P., Servis C., Michielin O., Freitag R., Moreillon P., Mermod N.
ISSN
0066-4804[print], 0066-4804[linking]
Statut éditorial
Publié
Date de publication
2005
Volume
49
Numéro
9
Pages
3847-3857
Langue
anglais
Notes
Publication types: In Vitro ; Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Résumé
Crushed seeds of the Moringa oleifera tree have been used traditionally as natural flocculants to clarify drinking water. We previously showed that one of the seed peptides mediates both the sedimentation of suspended particles such as bacterial cells and a direct bactericidal activity, raising the possibility that the two activities might be related. In this study, the conformational modeling of the peptide was coupled to a functional analysis of synthetic derivatives. This indicated that partly overlapping structural determinants mediate the sedimentation and antibacterial activities. Sedimentation requires a positively charged, glutamine-rich portion of the peptide that aggregates bacterial cells. The bactericidal activity was localized to a sequence prone to form a helix-loop-helix structural motif. Amino acid substitution showed that the bactericidal activity requires hydrophobic proline residues within the protruding loop. Vital dye staining indicated that treatment with peptides containing this motif results in bacterial membrane damage. Assembly of multiple copies of this structural motif into a branched peptide enhanced antibacterial activity, since low concentrations effectively kill bacteria such as Pseudomonas aeruginosa and Streptococcus pyogenes without displaying a toxic effect on human red blood cells. This study thus identifies a synthetic peptide with potent antibacterial activity against specific human pathogens. It also suggests partly distinct molecular mechanisms for each activity. Sedimentation may result from coupled flocculation and coagulation effects, while the bactericidal activity would require bacterial membrane destabilization by a hydrophobic loop.
Mots-clé
Amino Acid Sequence, Anti-Bacterial Agents/chemistry, Anti-Bacterial Agents/pharmacology, Bacteria/drug effects, Cell Membrane/drug effects, Culture Media, Escherichia coli/drug effects, Fungi/drug effects, Hemolysis/drug effects, Humans, Mass Spectrometry, Microbial Sensitivity Tests, Microscopy, Confocal, Models, Structural, Molecular Sequence Data, Moringa/chemistry, Peptides/chemistry, Peptides/pharmacology, Protein Conformation, Protein Structure, Tertiary, Seeds/chemistry, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Structure-Activity Relationship
Pubmed
Web of science
Open Access
Oui
Création de la notice
28/01/2008 11:22
Dernière modification de la notice
20/08/2019 14:44
Données d'usage