Bioactivity Profiling of In Silico Predicted Linear Toxins from the Ants Myrmica rubra and Myrmica ruginodis

Abstract

The venoms of ants (Formicidae) are a promising source of novel bioactive molecules with potential for clinical and agricultural applications. However, despite the rich diversity of ant species, only a fraction of this vast resource has been thoroughly examined in bioprospecting programs. Previous studies focusing on the venom of Central European ants (subfamily Myrmicinae) identified a number of short linear decapeptides and nonapeptides resembling antimicrobial peptides (AMPs). Here, we describe the in silico approach and bioactivity profiling of 10 novel AMP-like peptides from the fellow Central European myrmicine ants Myrmica rubra and Myrmica ruginodis. Using the sequences of known ant venom peptides as queries, we screened the venom gland transcriptomes of both species. We found transcripts of nine novel decapeptides and one novel nonapeptide. The corresponding peptides were synthesized for bioactivity profiling in a broad panel of assays consisting of tests for cytotoxicity as well as antiviral, insecticidal, and antimicrobial activity. U-MYRTX-Mrug5a showed moderately potent antimicrobial effects against several bacteria, including clinically relevant pathogens such as Listeria monocytogenes and Staphylococcus epidermidis, but high concentrations showed negligible cytotoxicity. U-MYRTX-Mrug5a is, therefore, a probable lead for the development of novel peptide-based antibiotics.

Engineering a wolf spider A-family toxin towards increased antimicrobial activity but low toxicity

“…A broader screen for antibacterial activity was carried out using a panel of seven bacterial strains as described previously [29]: Listeria monocytogenes (DSM 20600), Micrococcus luteus (DSM 20030), two Pseudomonas aeruginosa strains (DSM 1117 and DSM 50071), Staphylococcus aureus (DSM 2569), Staphylococcus epidermidis (DSM 28319) and Escherichia coli (DSM 102053). We seeded multiple 96-multiwell plates and exposed the panel to 200 μmol/L of each peptide in 100 μL medium, followed by OD 600 measurements in triplicate using a BioTek Eon microplate reader 18 h after peptide exposure.…”

“…The efficacy of AMPs, including their membranolytic activity, is mainly dependent on their charge and hydrophobicity, which can be modified by amino acid substitutions [26]. The replacement of single amino acids can generate new AMP-like peptides in this seemingly unlimited sequence space [27,28], but rational design based on the bioinformatic prediction of antimicrobial potential may provide a more effective strategy [29]. Here we harnessed our current knowledge on the properties of short linear peptides based on information provided by databases and prediction tools to enhance the antimicrobial potential of known AMPs [15][16][17]30].…”

Comparative venom analysis between melanistic and normally-colored phenotypes of the common adder (Vipera berus)

“…no. G7570) as previously reported (Hurka et al, 2022). The venoms were redissolved in cultivation medium and added to final concentrations of 1.56, 3.125, 6.25, 12.5 and 25 µg/ml.…”