Interaction of Acylated and Substituted Antimicrobial Peptide Analogs with Phospholipid–Polydiacetylene Vesicles. Correlation with their Biological Properties

Abstract

A series of peptide analogs based on region 6-22 of Plantaricin 149 sequence were synthesized. The interaction between these analogs and phospholipid-polydiacetylene vesicles was investigated to evaluate the ability of the bioassay to detect differences in the interaction of the peptides with dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylcholine vesicles, associated with amino acid substitution and N-terminal conjugation of the sequences with short fatty acids (8 and 12 carbon atoms). Fatty acid conjugation of peptides with low antimicrobial activity resulted in lipopeptides with improved activity against strains of Staphylococcus aureus and Listeria monocytogenes. The length of the fatty acid determined the bacterial specificity, and the conjugation with n-octanoic acid yielded the most active analog (C8-CT) against Staphylococcus aureus strain (MIC: 1.0 μm) while the conjugation with n-dodecanoic acid (C12-CT) was optimal for Listeria monocytogenes strain (MIC: 2.0 μm). In contrast, the substitution of Phe by Trp had an unfavorable effect on the antimicrobial activity. Hemolysis tests and membrane interaction studies with dipalmitoylphosphatidylcholine-polydiacetylene vesicles showed that lipopeptides interact to a greater extent with both biological and biomimetic membranes. Also, a good correlation was found between antimicrobial activity against Staphylococcus aureus strain and % colorimetric response values with dipalmitoylphosphatidylglycerol-polydiacetylene vesicles.

Biological and structural effects of the conjugation of an antimicrobial decapeptide with saturated, unsaturated, methoxylated and branched fatty acids

“…Spectra deconvolution indicated α‐helix contributions of 70–90% for the majority of the lipopeptides, while 4‐OMe‐C10:0‐A2 and C14:0‐A2 showed lower contributions of α‐helix (60% and 55%, respectively). These results agree with previous studies, indicating that Pln149a and lipopeptides of CT analog adopt α‐helical structure in the presence of DPPG vesicles .…”

“…This suggests an optimal fatty acid chain length for Listeria between C12 and C16. These results are consistent with those previously found for CT analogs of Pln149a (region 6-22) against L. monocytogenes, which state that conjugation with dodecanoic acid was much more effective than with octanoic acid (4 and 16 μM, respectively) [46].…”

“…Peptides covering region 6–22 of Pln 149a (named CT) were also synthesized and studied. We also found that the CT analog retains antimicrobial activity against the Gram (+) bacteria S. aureus and L. monocytogenes and the conjugation with octanoic and dodecanoic acids improved the CT inhibitory activity .…”

Synthetic surfactin analogues have improved anti-PEDV properties

“…Hemolysis is commonly used to assess the biosafety of lipopeptides [18,19]. As shown in Fig 3, SLPs have a range hemolytic activities.…”

Citral nanocontainers applied to guava fruits (Psidium Guajava L.) in postharvesting

“…Among these treatments is the application of maturation retardants such as citral (C10H16O). [11][12] This retardant is also beneficial due to its antimicrobial [13] and antifungal effects [14][15] as well as acting as an inhibitor for the biosynthesis of ethylene, [16] a transcendental metabolite in the fruit ripening process. [17][18].…”