New Mastoparan Peptides in the Venom of the Solitary Eumenine Wasp Eumenes micado

Abstract

Comprehensive LC-MS and MS/MS analysis of the crude venom extract from the solitary eumenine wasp Eumenes micado revealed the component profile of this venom mostly consisted of small peptides. The major peptide components, eumenine mastoparan-EM1 (EMP-EM1: LKLMGIVKKVLGAL-NH2) and eumenine mastoparan-EM2 (EMP-EM2: LKLLGIVKKVLGAI-NH2), were purified and characterized by the conventional method. The sequences of these new peptides are homologous to mastoparans, the mast cell degranulating peptides from social wasp venoms; they are 14 amino acid residues in length, rich in hydrophobic and basic amino acids, and C-terminal amidated. Accordingly, these new peptides can belong to mastoparan peptides (in other words, linear cationic α-helical peptides). Indeed, the CD spectra of these new peptides showed predominantly α-helix conformation in TFE and SDS. In biological evaluation, both peptides exhibited potent antibacterial activity, moderate degranulation activity from rat peritoneal mast cells, and significant leishmanicidal activity, while they showed virtually no hemolytic activity on human or mouse erythrocytes. These results indicated that EMP-EM peptides rather strongly associated with bacterial cell membranes rather than mammalian cell membranes.

Chemical and Biological Characteristics of Antimicrobial α-Helical Peptides Found in Solitary Wasp Venoms and Their Interactions with Model Membranes

“…However, they were found by transcriptomic analysis, and the biological activities were not investigated [27]. EMP-EM1 and EMP-EM2 from Eumenes micado are the most recently found mastoparan peptides, and highly homologous to EMP-AF [13]. They show antimicrobial and mast cell degranulating activities at similar extent as EMP-AF, but virtually no hemolytic activity.…”

“…Eumenine mastoparan-AF (EMP-AF) was the first antimicrobial peptide to be found in solitary wasp venoms in the year 2000 [8]. Since then, several other antimicrobial peptides have been found, mostly in solitary eumenine wasp venoms [9,10,11,12,13,14]. These peptides are only 10–15 amino acids in length, are rich in hydrophobic and basic amino acids with no disulfide bond, and can adopt an α-helical amphipathic secondary structure under appropriate conditions.…”

“…Besides the antimicrobial activity, they commonly show histamine-release from mast cells, as well as hemolytic and leishmanicidal activities. Physicochemical properties of these peptides, i.e., charge, hydrophobicity, and amphipathicity, have been investigated, and some of these properties were shown to be important to our understanding of the structure-function relationship and useful for the design of new sequences with improved biological properties [10,11,12,13,14,15]. The biological activities of these peptides may be due to the adoption of an amphipathic α-helical secondary structure that inserts into the lipids of biological membranes.…”

Wasp venom peptide, synoeca‐MP, from Synoeca surinama shows antimicrobial activity against human and animal pathogenic microorganisms

“…Therefore, tests were performed to evaluate the cytotoxicity of synoeca‐MP against a mice red blood cell concentrate. The hemolysis assay was chosen because it is one of the most used to evaluate the cytotoxicity of molecules with antimicrobial potential . The hemolytic action has an EC50 of 185 μM, which represents a dose 17 times higher than the highest dose used in the bacterial inhibition test (Figure F).…”

Mastoparan Dissipates Mitochondrial Transmembrane Potential in the Physiological (ADP-LIKE) Range

“…Mastoparan and its analogs displayed a broad-spectrum antimicrobial activity against bacteria and fungi and were highly potent against antibioticresistant bacteria [2]. The mastoparans are 14 amino acids in length with the C-terminus amidated and rich in hydrophobic and basic amino acids, which leads to amphipathic chemical character, adopting α-helical secondary structure under proper conditions [3]. Due to biological activities, showing histamine releasing from mast cells, antimicrobial and hemolytic activities, mastoparans have been developed for pharmacological research and for therapeutic use, in particular, as antimicrobial agents [4][5][6].…”