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Structural requirements for antimicrobial versus chemoattractant activities for dermaseptin S9
Constance Auvynet1, Chahrazade El Amri, Claire Lacombe
1UPMC Université de Paris 06, CNRS FRE 2852, Peptidome de la Peau des Amphibiens, Paris Cedex 5, France.
The FEBS Journal
|July 19, 2008
Summary
Dermaseptin S9 (Drs S9), a frog-derived peptide, forms amyloid-like structures that modulate its antimicrobial and immune cell-attracting activities. These properties are linked to its unique beta-sheet aggregation, influencing its biological functions.
Area of Science:
- Biochemistry
- Molecular Biology
- Immunology
Background:
- Dermaseptin S9 (Drs S9) is a unique antimicrobial peptide from frog skin with a hydrophobic core and cationic termini.
- Previous research indicated Drs S9 adopts an alpha-helical structure in TFE/water but aggregates in aqueous solutions.
Purpose of the Study:
- To investigate the structural properties of Drs S9 in aqueous environments and on lipid bilayers.
- To elucidate the relationship between Drs S9's structure, aggregation, and its antimicrobial and chemotactic activities.
Main Methods:
- Circular dichroism (CD) spectroscopy
- Fourier-transform infrared (FTIR) spectroscopy
- Attenuated total reflectance FTIR (ATR-FTIR)
- Surface plasmon resonance (SPR)
- Electron microscopy (EM)
- Congo red staining
Main Results:
- Drs S9 forms stable, ordered beta-sheet aggregates in aqueous buffers and on phospholipid vesicles.
- These aggregates self-assemble into amyloid-like fibrils through spherical intermediates.
- Drs S9 induces directional migration of neutrophils, T lymphocytes, and monocytes.
- Antimicrobial activity is associated with spherical oligomers, while chemotactic activity is linked to soluble forms.
Conclusions:
- Drs S9 exhibits amyloid-like aggregation behavior in aqueous and membrane-bound states.
- The peptide's antimicrobial and immunomodulatory functions are modulated by its aggregation state and amyloidogenic properties.
- Drs S9's activities occur at concentrations comparable to known amyloidogenic peptides, suggesting a role for aggregation in its biological effects.
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