The Antimicrobial Domains of Wheat Puroindolines Are Cell-Penetrating Peptides with Possible Intracellular Mechanisms of Action
| Autor: | Joe Panozzo, Enzo A. Palombo, Mrinal Bhave, Rebecca L. Alfred |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
DNA
Bacterial Cell Membrane Permeability Indoles Saccharomyces cerevisiae Antimicrobial peptides Molecular Sequence Data Intracellular Space lcsh:Medicine Peptide Cell-Penetrating Peptides Microbial Sensitivity Tests Cell membrane chemistry.chemical_compound Anti-Infective Agents medicine Escherichia coli Propidium iodide Amino Acid Sequence lcsh:Science Triticum chemistry.chemical_classification Multidisciplinary biology lcsh:R Haemolysis biology.organism_classification Membrane medicine.anatomical_structure chemistry Biochemistry lcsh:Q Intracellular Research Article |
| Zdroj: | PLoS ONE PLoS ONE, Vol 8, Iss 10, p e75488 (2013) |
| ISSN: | 1932-6203 |
| Popis: | The puroindoline proteins (PINA and PINB) of wheat display lipid-binding properties which affect the grain texture, a critical parameter for wheat quality. Interestingly, the same proteins also display antibacterial and antifungal properties, attributed mainly to their Tryptophan-rich domain (TRD). Synthetic peptides based on this domain also display selectivity towards bacterial and fungal cells and do not cause haemolysis of mammalian cells. However, the mechanisms of these activities are unclear, thus limiting our understanding of the in vivo roles of PINs and development of novel applications. This study investigated the mechanisms of antimicrobial activities of synthetic peptides based on the TRD of the PINA and PINB proteins. Calcein dye leakage tests and transmission electron microscopy showed that the peptides PuroA, Pina-M and Pina-W→F selectively permeabilised the large unilamellar vesicles (LUVs) made with negatively charged phospholipids mimicking bacterial membranes, but were ineffective against LUVs made with zwitterionic phospholipids mimicking eukaryotic membranes. Propidium iodide fluorescence tests of yeast (Saccharomyces cerevisiae) cells showed the peptides were able to cause loss of membrane integrity, PuroA and Pina-M being more efficient. Scanning electron micrographs of PINA-based peptide treated yeast cells showed the formation of pits or pores in cell membranes and release of cellular contents. Gel retardation assays indicated the peptides were able to bind to DNA in vitro, and the induction of filamental growth of E. coli cells indicated in vivo inhibition of DNA synthesis. Together, the results strongly suggest that the PIN-based peptides exert their antimicrobial effects by pore formation in the cell membrane, likely by a carpet-like mechanism, followed by intracellular mechanisms of activity. |
| Databáze: | OpenAIRE |
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