New predatory interaction of Trichonephila clavipes (Araneae: Nephilidae) on Fidicinini (Hemiptera: Cicadidae) in a forest fragment of the Neotropical region

Posted by
  New predatory interaction of Trichonephila clavipes (Araneae: Nephilidae) on Fidicinini (Hemiptera: Cicadidae) in a forest fragment of the Neotropical region Abstract Trichonephila clavipes (Araneae: Nephilidae) is an orb web-building spider whose diet is primarily based on flying insects. This note aims to report the first predatory interaction of T. clavipes on a cicada of the genus Fidicina (Hemiptera: Cicadidae) in a fragment of the Atlantic Forest in Brazil. The predation event was observed (ad libitum) in the Benjamin Maranhão Botanical Garden situated in the Mata do Buraquinho Wildlife Refuge, northeastern Brazil. A specimen of Fidicina sp. was found freshly dead and trapped in the web of T. clavipes. The nephilid was observed moving slowly between the ventral and dorsal regions of the Fidicina sp. without weaving a web around the cicadid. Then, T. clavipes was observed perched on the left side of the Fidicina sp., with its pedipalps and chelicerae manipulating the thorax ...

Isolation, Synthesis, and Pharmacological Characterization of a Short-Structured Peptide from the Venom of Phidippus Audax that Affects Potassium Currents

Posted by

 

Isolation, Synthesis, and Pharmacological Characterization of a Short-Structured Peptide from the Venom of Phidippus Audax that Affects Potassium Currents

Abstract

Purpose

Little is known about the venom of Salticidae spiders, so here, we look for venom peptides of the most cosmopolitan spider, Phidippus audax.

Methods

The isolation, chemical synthesis, and pharmacological characterization of a short peptide from the venom of the spider Phidippus audax (Araneae: Salticidae) was performed by HPLC chromatography, solid-phase peptide synthesis, and electrophysiology on rat dorsal root ganglia neurons, respectively.

Results

The unveiled peptide (Paudax1) consists of 22 residues and contains a single disulfide bridge. Paudax1 has paralytic activity against Acheta domesticus. It was synthesized in two N-terminal forms, Phi-Ala and Phi-Trp. . The pharmacology of both homologous peptides was evaluated in primary cultures of rat dorsal root ganglia neurons. Microperfusion of Phi-Ala [10 µM] (n = 6) resulted in a 17 ± 5% inhibition of the maximum amplitude of the outward current (p < 0.05) and a non-significant decrease of 22 ± 7% (p > 0.05) in the current amplitude at the end of the voltage pulse (IKend). Additionally, Phi-Ala did not affect the current inactivation time course (τinact). Meanwhile, the peptide Phi-Trp [10 µM] (n = 6) induced a 37 ± 3.6% inhibition (p ≤ 0.01) of the maximum amplitude of the outward current and a 44 ± 5% inhibition (p ≤ 0.01) in IKend, with no change in τinact.

Conclusion

Although both peptides, Phi-Ala and Phi-Trp, displayed insecticidal paralytic activity, they exhibited relatively low efficiency as blockers of the outward current at the concentrations used, and did not affect the inward currents. Phi-Trp and Phi-Ala are worth investigating to explore their therapeutic potential.

Salceda, E., Arenas, I., Olamendi-Portugal, T. et al. Isolation, Synthesis, and Pharmacological Characterization of a Short-Structured Peptide from the Venom of Phidippus Audax that Affects Potassium Currents. Int J Pept Res Ther 32, 15 (2026). https://doi.org/10.1007/s10989-025-10792-1