A facile and dynamic assay for the detection of peptide aggregation

Peptide Amphiphilic-Based Supramolecular Structures with Anti-HIV-1 Activity

In a previous work, we defined a novel HIV-1 fusion inhibitor peptide (E1P47) with a broad spectrum of activity against viruses from different clades, subtypes, and tropisms. With the aim to enhance its efficacy, in the present work we address the design and synthesis of several peptide amphiphiles (PAs) based on the E1P47 peptide sequence to target the lipid rafts of the cell membrane where the cell-cell fusion process takes place. We report the synthesis of novel PAs having a hydrophobic moiety covalently attached to the peptide sequence through a hydrophilic spacer of polyethylene glycol. Characterization of self-assembly in condensed phase and aqueous solution as well as their interaction with model membranes was analyzed by several biophysical methods. Our results demonstrated that the length of the spacer of polyethylene glycol, the position of the peptide conjugation as well as the type of the hydrophobic residue determine the antiviral activity of the construct. Peptide amphiphiles with one alkyl tail either in C-terminus (C-PAmonoalkyl) or in N-terminus (N-PAmonoalkyl) showed the highest anti-HIV-1 activities in the cellular model of TZM-bl cells or in a preclinical model of the human mucosal tissue explants.

Short lipopeptides specifically inhibit the growth of Propionibacterium acnes with a dual antibacterial and anti-inflammatory action

BACKGROUND AND PURPOSE

Propionibacterium acnes is a Gram-positive bacterium associated with the skin disorder acne. In this study, as fatty acids are considered to be important in the life habitat of P. acnes, we tested our lipopeptide library in an attempt to create potent P. acnes-specific antimicrobial agents.

EXPERIMENTAL APPROACH

The antimicrobial activity of various lipopeptides was determined by measuring their minimal inhibitory concentration (MIC). Lipids from P. acnes were used to explore their mode of action. RAW264.7 cells stimulated with LPS and P. acnes respectively were used to measure their anti-inflammatory activity. Mice ears injected with P. acnes were used to assess the antimicrobial and anti-inflammatory effects of the peptides tested in vivo.

KEY RESULTS

The most potent candidate, C16-KWKW, was observed to be more active against P. acnes than against other non-targeted bacterial strains, such as Streptococcus mutans, Staphylococcus aureus, and Escherichia coli. The mode of action of C16-KWKW was observed to be through interference with the integrity of the bacterial membrane, thereby impairing membrane permeability and causing leakage of inner contents of bacterial cells. Furthermore, C16-KWKW inhibited the expression of pro-inflammatory cytokines, such as IL-1β, TNF-α, and inducible NOS stimulated by both LPS and P. acnes, thus showing potential anti-inflammatory activity, which was further verified in the in vivo animal studies.

CONCLUSIONS AND IMPLICATIONS

C16-KWKW is a lipopeptide displaying both anti-P. acnes and anti-inflammatory effects in vitro and in vivo and shows potential as a treatment for acne vulgaris induced by P. acnes.

Short lipopeptides specifically inhibit the growth of Propionibacterium acnes with dual antibacterial and anti-inflammatory action

BACKGROUND AND PURPOSE

Propionibacterium acnes (P. acnes) is a Gram-positive bacterium associated with the skin disorder acne. In this study, we determined the importance of fatty acids in the life habitat of P. acnes; we tested our lipopeptide library in an attempt to create potent P. acnes-specific antimicrobial agents.

EXPERIMENTAL APPROACH

Antimicrobial activity was determined by the minimal inhibitory concentration (MIC). Lipids from P. acnes were used to explore the mode of action. RAW264.7 cells respectively stimulated with LPS and P. acnes were used to measure the anti-inflammatory activity. Mice ears injected with P. acnes were used to assess the antimicrobial and anti-inflammatory effects of the peptides tested in vivo.

KEY RESULTS

The most potent candidate, C16-KWKW, was observed to be more active against P. acnes, with an MIC of 2 μg·ml^-1 , than against other non-targeted bacterial strains, such as Streptococcus mutans, Staphylococcus aureus, and Escherichia coli. The mode of action of C16-KWKW was observed to be through interference with the integrity of bacterial membrane, thereby impairing membrane permeability and causing leakage of the inner contents of bacterial cells. In addition, C16-KWKW inhibited the expression of pro-inflammatory cytokines, such as IL-1β, TNF-α, and inducible NOS, stimulated by both LPS and P. acnes, thus showing potential anti-inflammatory activity, which was further assessed in animal studies in vivo.

CONCLUSIONS AND IMPLICATIONS

C16-KWKW is a lipopeptide displaying both anti-P. acnes and anti-inflammatory effects in vitro and in vivo, and exhibits potential as a treatment for acne vulgaris induced by P. acnes.