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Silver adducts of four-branched histidine rich peptides exhibit synergistic antifungal activity.
- Source :
-
Biochemical and biophysical research communications [Biochem Biophys Res Commun] 2016 Sep 02; Vol. 477 (4), pp. 957-962. Date of Electronic Publication: 2016 Jul 04. - Publication Year :
- 2016
-
Abstract
- Previously, a four branched histidine-lysine rich peptide, H3K4b, was shown to demonstrate selective antifungal activity with minimal antibacterial activity. Due to the potential breakdown from proteases, H3K4b was further evaluated in the current study by varying the D- and l-amino acid content in its branches. Whereas analogues of H3K4b that selectively replaced l-amino acids (H3k4b, h3K4b) had improved antifungal activity, the all d-amino acid analogue, h3k4b, had reduced activity, suggesting that partial breakdown of the peptide may be necessary. Moreover, because histidines form coordination bonds with the silver ion, we examined whether silver adducts can be formed with these branched histidine-lysine peptides, which may improve antifungal activity. For Candida albicans, the silver adduct of h3K4b or H3k4b reduced the MIC compared to peptide and silver ions alone by 4- and 5-fold, respectively. For Aspergillus fumigatus, the silver adducts showed even greater enhancement of activity. Although the silver adducts of H3k4b or h3K4b showed synergistic activity, the silver adduct with the all l-amino acid H3K4b surprisingly showed the greatest synergistic and growth inhibition of A. fumigatus: the silver adduct of H3K4b reduced the MIC compared to the peptide and silver ions alone by 30- and 26-fold, respectively. Consistent with these antifungal efficacy results, marked increases in free oxygen radicals were produced with the H3K4b and silver combination. These studies suggest that there is a balance between stability and breakdown for optimal antifungal activity of the peptide alone and for the peptide-silver adduct.<br /> (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Subjects :
- Antifungal Agents chemical synthesis
Apoptosis drug effects
Cell Survival drug effects
Dose-Response Relationship, Drug
Drug Design
Drug Synergism
Histidine chemistry
Peptides chemistry
Silver chemistry
Antifungal Agents administration & dosage
Aspergillus fumigatus cytology
Aspergillus fumigatus drug effects
Histidine administration & dosage
Peptides administration & dosage
Silver administration & dosage
Subjects
Details
- Language :
- English
- ISSN :
- 1090-2104
- Volume :
- 477
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Biochemical and biophysical research communications
- Publication Type :
- Academic Journal
- Accession number :
- 27387239
- Full Text :
- https://doi.org/10.1016/j.bbrc.2016.07.008