Hidden diversity in plain sight: four new species of Nemesia (Araneae: Mygalomorphae) from the Córdoba Province of Spain

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  Hidden diversity in plain sight: four new species of Nemesia (Araneae: Mygalomorphae) from the Córdoba Province of Spain Abstract A taxonomic revision of the species of Nemesia Audouin, 1826, distributed in the vicinity of Córdoba City, southern Spain, is presented. Four new species are described: Nemesia morana sp. nov. (female), N. kodama sp. nov. (male and female), N. rosae sp. nov. (male and female), and N. tamajoni sp. nov. (male and female). These species are distinguished by distinct morphological characters, including the shape of the spermathecae, palpal bulbs, and spinnerets, as well as by burrow architecture. Fieldwork was conducted across two of the three major habitat types in the region—the humid, forested mountains of Sierra Morena and the croplands and riparian forests of the Guadalquivir Valley—while the third, the “campiña”, which is mainly composed of agricultural landscapes, remains poorly explored. Sampling methods included pitfall trapping and the direct e...

Inhibition of proteolytic activity of Bothrops alternatus venom by two small molecules and docking analysis against a snake venom metalloproteinase

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Inhibition of proteolytic activity of Bothrops alternatus venom by two small molecules and docking analysis against a snake venom metalloproteinase

Abstract

The only effective treatment against snakebites is the administration of antivenom. Snake venom metalloproteinases (SVMPs) play a key role in the pathogenesis of envenomation. In this work, the ability of two molecules to inhibit the proteolytic activity of Bothrops alternatus venom and its PIII SVMP (baltergin) was studied: a dye (alizarin red S: Az) and a vitamin (L-ascorbic acid: AA). Neutralization of hemorrhage and docking analysis were also carried out. The inhibition of the proteolytic activity, showed the IC50 for Az (3.6 mM) was 52 times lower than for AA (188.2 mM). Az was not only able to inhibit casein degradation but also a milk protein compatible with beta-lactoglobulin, meanwhile AA was only capable of inhibit the degradation of casein. Both molecules were able to completely inhibit the action of baltergin on casein degradation. It was also observed that the antioxidant activity of Az increased, while the activity of AA decreased after exposition to visible radiation. As a result, Az induced an increase in its proteolytic inhibitory potential, although no significant changes were observed with AA. A partial neutralization of hemorrhage was observed, representing 46% of inhibition, only for Az at a venom:molecule ratio (m:m) of 1:4. It was demonstrated that Az interacts with PIII SVMPs through more bonds than with AA, which makes it fit better in the vicinity of the catalytic site. Natural (or synthetic) dyes open up a new range of possibilities for exploring alternatives for the complementary treatment of snakebites.
Echeverría, S. M., Blanco, G. C., Pereira, M. D. C. G., Maruñak, S. L., Ferreras, J. M., & Gay, C. C. (2025). Inhibition of proteolytic activity of Bothrops alternatus venom by two small molecules and docking analysis against a snake venom metalloproteinase. Biochimie. https://doi.org/10.1016/j.biochi.2025.08.009