Clinical characteristics and long-term disabilities in children following Bothrops atrox envenomation in Manaus, western Brazilian Amazon

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  Image Credit: By Darío De la Fuente - https://www.inaturalist.org/photos/113840233, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=129474300 Clinical characteristics and long-term disabilities in children following Bothrops atrox envenomation in Manaus, western Brazilian Amazon Abstract Background:   In the Brazilian Amazon, most snakebites are caused by Bothrops atrox . Although pediatric cases are less frequent, children are more vulnerable to severe complications and long-term disabilities. This study aims to describe the clinical profile of B. atrox envenomation in children treated at a tertiary hospital in Manaus, in Western Brazilian Amazon, and to characterize the resulting long-term musculoskeletal impairments in a subgroup of these patients. Methods:   We retrospectively analyzed sociodemographic and clinical data from patients up to 12 years and 11 months of age treated between January 2010 and December 2023. A total of 258 children who were ...

Spider peptides from Brachypelma smithi with slightly different amino acids at their C-terminal loops exert different insecticidal activities

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Spider peptides from Brachypelma smithi with slightly different amino acids at their C-terminal loops exert different insecticidal activities

Abstract

The insecticidal molecules of spiders persistently evolve to ensure rapid paralysis of their prey, and the best molecules are transmitted to their progeny. Here, we cloned two insecticidal peptides, Bs2 and Bs3, from the venom glands of the theraphosid Brachypelma smithi. Bs2 and Bs3 are 90.2% identical, but they exhibit interesting structural differences at their C-termini, including a connecting disulfide bond (residues Cys15-Cys36 for Bs2 and Cys15-Cys30 for Bs3). The genomic origin of Bs2 and Bs3 may be a cause for gene duplication events. Moreover, Bs2 differs in two residues from Tal1 (95.1% identical), an insecticidal peptide, from the tarantula Tliltocatl albopilosus. Likewise, Bs3 is similar to Asp3a from Aphonopelma sp., a peptide that targets mammalian Cav (voltage-dependent Ca2 + channel), but it has not been tested in insects. Bs2 and Bs3 were cloned and recombinantly expressed in bacterial cells, and their paralytic effects were tested on three species of insects. The insecticidal peptide rBs2 with the connecting loop Cys15-Cys36 was significantly more insecticidal than that of rBs3 when affecting Galleria mellonella larvae (Lepidoptera). Yet, the insecticidal peptide rBs3 with the connecting loop Cys15-Cys30 was significantly more insecticidal than that of rBs2 when affecting Acheta domesticus nymph crickets (Orthoptera), and Gromphadorhina portentosa cockroaches (Blattodea). rBs2 and rBs3 structural models show a low-structured C-terminal in rBs3, which correlates with a more flexible amino acid sequence of such C-terminal from residues Tyr30 to Leu42. Since insecticidal spider peptides are constantly evolving for prey capture, they are valuable ion channel antagonists for understanding insect cell receptors, and they are also promising leads for insect control.

Clement, H., Corrales-García, L., Carpanta, V. et al. Spider peptides from Brachypelma smithi with slightly different amino acids at their C-terminal loops exert different insecticidal activities. Amino Acids (2026). https://doi.org/10.1007/s00726-026-03521-5