Harnessing snake venom cardiotoxins for antimicrobial peptide discovery

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  Harnessing snake venom cardiotoxins for antimicrobial peptide discovery Abstract Snake venoms are a rich source of bioactive molecules with considerable potential for drug discovery. Cardiotoxins (CTXs) from cobras ( Naja spp.) are membrane-active venom proteins and promising templates for antimicrobial peptide development. Here, we combined two computational toxin-mining strategies to identify antimicrobial peptide candidates from CTXs. First, AMPA-guided sequence mining was used to detect encrypted antimicrobial regions within CTX sequences. Second, sequence alignment and consensus-sequence analysis were employed to generate peptides from a conserved CTX scaffold. Candidate peptides were prioritised using multiple machine learning- and deep learning-based antimicrobial peptide prediction tools, resulting in fourteen CTX-inspired peptides, including two modified derivatives of CTX-p5. Antimicrobial screening showed limited activity across the peptide panel, with CTX-p5 exhibiti...

Declining freshwater habitats in Greenland may shift diets of the ubiquitous wolf spider Pardosa glacialis

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Declining freshwater habitats in Greenland may shift diets of the ubiquitous wolf spider Pardosa glacialis


Abstract

Freshwater habitats in Arctic landscapes provide essential food resources to predaceous terrestrial fauna. However, climate change threatens the continuation of aquatic resources as increased temperatures prompt widespread drying. We investigated how declines in surface waters in the Arctic may have implications for the diets of the wolf spider Pardosa glacialis (Araneae: Lycosidae), an abundant top predator in western Greenland known to consume both aquatic and terrestrial prey. We estimated the abundance of ground-dwelling prey taxa near and far from shallow ponds to compare resource availability for P. glacialis. We also measured the stable isotopes ratios of carbon and nitrogen of potential prey taxa and used linear mixing models to estimate the relative proportions of aquatic and terrestrial prey in the diets of P. glacialis collected near ponds versus drier, upland locations. Overall, near ponds there was a 3.7 times greater abundance of ground-dwelling organisms compared to locations far from ponds. Near ponds, depleted δ13C values of P. glacialis compared to the upland locations were explained by the consumption of aquatic insects, which were relatively depleted in 13C compared to terrestrial ground-dwelling and canopy taxa. Our linear mixing model indicated that the mean relative contribution of aquatic taxa to the diets of P. glacialis at pond locations was ~ 23% versus ~ 0% at upland locations, though these results were accompanied by significant uncertainty. Our results emphasize the importance of Arctic ponds in providing habitat to potential prey of terrestrial predators. We highlight how climate change, and the continued disappearance of aquatic habitats, could disrupt critical linkages between aquatic insects and terrestrial predators.

Bliska, H.M., DeSiervo, M.H., Virginia, R.A. et al. Declining freshwater habitats in Greenland may shift diets of the ubiquitous wolf spider Pardosa glacialis. Polar Biol (2024). https://doi.org/10.1007/s00300-024-03259-4