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...

Temperature-induced changes in lipids and fatty acids in spiders

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Temperature-induced changes in lipids and fatty acids in spiders

Abstract

Temperature variations significantly impact the development, reproduction, and physiological functioning of organisms, particularly in ectothermic species, where physiological adaptations are crucial to maintain metabolic processes under changing thermal conditions. Alterations in lipid composition play a key role in preventing the malfunction of lipid systems when exposed to extreme temperatures. We analysed the lipid and fatty acid composition of two key organs, the midgut diverticula and muscle, of the spider Polybetes pythagoricus, following a 20-day acclimatization to 1, 4, 25, and 35°C. In adult muscle acclimatized to low temperatures, we observed an increase in phosphatidylcholine and cholesterol, with a corresponding decrease in phosphatidylethanolamine. In juvenile midgut diverticula, triacylglycerol levels decreased at the highest temperature, while phosphatidylcholine increased in muscle at low temperatures. Regarding fatty acids, lower temperatures generally led to an increase in unsaturated fatty acids (16:1 and 18:1) and a decrease in saturated fatty acids (17:0 and 20:0). We conclude that thermal acclimatization in P. pythagoricus induces previously undescribed changes in lipid and fatty acid composition. These variations are diverse and, in some cases, organ-specific or dependent on developmental stage.

Gabriel Molina, Aldana Laino, Luciano Peralta, Carlos Fernando Garcia "Temperature-induced changes in lipids and fatty acids in spiders," Arachnology, 20(5), 709-716, (8 July 2026)