Dataset Information

Peptide-Stabilized Emulsions and Gels from an Arginine-Rich Surfactant-like Peptide with Antimicrobial Activity.

ABSTRACT: The preparation of hydrogels and stable emulsions is important in the formulation of many functional nanostructured soft materials. We investigate the multifunctional self-assembly and bioactivity properties of a novel surfactant-like peptide (SLP) that shows antimicrobial activity, is able to form hydrogels without pH adjustment, and is able to stabilize oil-in-water emulsions. Furthermore, we demonstrate on-demand de-emulsification in response to the protease enzyme elastase. We show that SLP (Ala)9-Arg (A9R) forms ?-sheet fibers above a critical aggregation concentration and that water-in-oil emulsions are stabilized by a coating of ?-sheet fibers around the emulsion droplets. Furthermore, we demonstrate enzyme-responsive de-emulsification, which has potential in the development of responsive release systems. The peptide shows selective antimicrobial activity against Gram-negative pathogens including Pseudomonas aeruginosa, which causes serious infections. Our results highlight the utility of SLPs in the stabilization of oil/water emulsions and the potential for these to be used to formulate antimicrobial peptide emulsions which are additionally responsive to protease. The peptide A9R has pronounced antibacterial activity against clinically challenging pathogens, and its ability to form ?-sheet fibers plays a key role in its diverse structural properties, ranging from hydrogel formation to emulsion stabilization.

SUBMITTER: Castelletto V

PROVIDER: S-EPMC7005944 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Peptide-Stabilized Emulsions and Gels from an Arginine-Rich Surfactant-like Peptide with Antimicrobial Activity.

Castelletto Valeria V Edwards-Gayle Charlotte J C CJC Hamley Ian W IW Barrett Glyn G Seitsonen Jani J Ruokolainen Janne J

ACS applied materials & interfaces 20190301 10

The preparation of hydrogels and stable emulsions is important in the formulation of many functional nanostructured soft materials. We investigate the multifunctional self-assembly and bioactivity properties of a novel surfactant-like peptide (SLP) that shows antimicrobial activity, is able to form hydrogels without pH adjustment, and is able to stabilize oil-in-water emulsions. Furthermore, we demonstrate on-demand de-emulsification in response to the protease enzyme elastase. We show that SLP ...[more]

PMID: 30785266

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Project description:Antimicrobial activity of many AMPs can be improved by lysine-to-arginine substitution due to a more favourable interaction of arginine guanidinium moiety with bacterial membranes. In a previous work, the structural and functional characterization of an amphipathic antimicrobial peptide named RiLK1, including lysine and arginine as the positively charged amino acids in its sequence, was reported. Specifically, RiLK1 retained its β-sheet structure under a wide range of environmental conditions (temperature, pH, and ionic strength), and exhibited bactericidal activity against Gram-positive and Gram-negative bacteria and fungal pathogens with no evidence of toxicity on mammalian cells. To further elucidate the influence of a lysine-to-arginine replacement on RiLK1 conformational properties, antimicrobial activity and peptide-liposome interaction, a new RiLK1-derivative, named RiLK3, in which the lysine is replaced with an arginine residue, was projected and characterised in comparison with its parental compound. The results evidenced that lysine-to-arginine mutation not only did not assure an improvement in the antimicrobial potency of RiLK1 in terms of bactericidal, virucidal and fungicidal activities, but rather it was completely abolished against the hepatitis A virus. Therefore, RiLK1 exhibited a wide range of antimicrobial activity like other cationic peptides, although the exact mechanisms of action are not completely understood. Moreover, tryptophan fluorescence measurements confirmed that RiLK3 bound to negatively charged lipid vesicles with an affinity lower than that of RiLK1, although no substantial differences from the structural and self-assembled point of view were evidenced. Therefore, our findings imply that antimicrobial efficacy and selectivity are affected by several complex and interrelated factors related to substitution of lysine with arginine, such as their relative proportion and position. In this context, this study could provide a better rationalisation for the optimization of antimicrobial peptide sequences, paving the way for the development of novel AMPs with broad applications.

Dataset Information

Peptide-Stabilized Emulsions and Gels from an Arginine-Rich Surfactant-like Peptide with Antimicrobial Activity.

Publications

Peptide-Stabilized Emulsions and Gels from an Arginine-Rich Surfactant-like Peptide with Antimicrobial Activity.

Similar Datasets

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