Antimicrobial Activity and Toxicity of Analogs of Wasp Venom EMP Peptides. Potential Influence of Oxidized Methionine

The antibiotic and toxic properties for four synthetic analogs of eumenine mastoparan peptides (EMP) have been tested. These properties were compared to two natural peptides found in the venom of solitary wasps <i>Anterhynchium flavomarginatum micado</i> (natural peptide EMP-AF) and <...

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Bibliographic Details
Main Authors: Roberto de la Salud Bea, Lily J. North, Sakura Horiuchi, Elaine R. Frawley, Qian Shen
Format: Article
Language:English
Published: MDPI AG 2021-10-01
Series:Antibiotics
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Online Access:https://www.mdpi.com/2079-6382/10/10/1208
Description
Summary:The antibiotic and toxic properties for four synthetic analogs of eumenine mastoparan peptides (EMP) have been tested. These properties were compared to two natural peptides found in the venom of solitary wasps <i>Anterhynchium flavomarginatum micado</i> (natural peptide EMP-AF) and <i>Eumenes rubrofemoratus</i> (natural peptide EMP-ER), respectively. Only EMP-AF-OR showed concentration-dependent growth inhibition against all bacterial species tested. Gram positive species had MIC values of 10 μg/mL for <i>B. subtilis</i> and 25 μg/mL for <i>S. aureus.</i> Gram negative species had MIC values of 25 μg/mL for <i>E. coli</i> and 200 μg/mL for <i>P. aeruginosa</i>. Of the other tested peptides, EMP-ER-D2K2 also showed activity and inhibited growth of <i>Bacillus subtilis</i> in a concentration-dependent manner at 200 μg/mL. Peptide EMP-ER-OR reduced the final density of <i>Escherichia coli</i> and <i>B. subtilis</i> cultures but did not impact their growth kinetics. Peptides EMP-AF-OR, EMP-ER-OR, and EMP-ER-D2K2 showed limited antifungal activity against <i>Candida albicans</i> or <i>Histoplasma capsulatum</i>. The hemolytic activity of the analogs were moderated though reports of the natural peptides, especially EMP-AF-OR, already showed low toxicity against erythrocytes. These results are discussed in the context of the potential influence of oxidized methionine on EMP activity.
ISSN:2079-6382