Multiomics profiling of toxins in the venom of the Amazonian spider Acanthoscurria juruenicola

Acanthoscurria juruenicola is an Amazonian spider described for the first time almost a century ago. However, little is known about their venom composition. Here, we present a multiomics characterization of A. juruenicola venom by a combination of transcriptomics, proteomics, and peptidomics approaches. Transcriptomics of female venom glands resulted in 93,979 unique assembled mRNA transcript encoding proteins. A total of 92 proteins were identified in the venom by mass spectrometry, including 14 mature cysteine-rich peptides (CRPs). Quantitative analysis showed that CRPs, cysteine-rich secretory proteins, metalloproteases, carbonic anhydrases, and hyaluronidase comprise >90% of the venom proteome. Relative quantification of venom toxins was performed by DIA and DDA, revealing converging profiles of female and male specimens by both methods. Biochemical assays confirmed the presence of active hyaluronidases, phospholipases, and proteases in the venom. Moreover, the venom promoted in vivo paralytic activities in crickets, consistent with the high concentration of CRPs. Overall, we report a comprehensive analysis of the arsenal of toxins of A. juruenicola and highlight their potential biotechnological and pharmacological applications. Mass spectrometry data were deposited to the ProteomeXchange Consortium via the PRIDE repository with the dataset identifier PXD013149 and via the MassIVE repository with the dataset identifier MSV000087777.

Presence of a neprilysin on Avicularia juruensis (Mygalomorphae: Theraphosidae) venom

Spiders are the most successful and diversified group of venomous animals. Currently, there are more than 49,000 species distributed almost all over the world. This broad distribution suggests that they have efficient strategies to improve their survival; one of them is the production of highly elaborate venoms, which are a heterogeneous mixture of molecules like inorganic salts, peptides, proteins, and enzymes. Considering this, this study aimed to analyze the venom of the spider Avicularia juruensis (Mygalomorphae: Theraphosidae) searching for proteolytic enzymes. Using zymography, electrophoresis, transcriptomics and proteomics approaches we identified one neprilysin able to degrade casein, that we named “Ajur_Neprilysin”. Neprilysins are metalloendopeptidases whose presence has already been described in animal venoms, however, its function has not yet been elucidated. Our results showed for the first time one non-bacterial neprilysin which can cleave casein and suggest that its role in envenomation is to degrade the extracellular matrix, facilitating the access of other toxins to their targets, as well as digestive fluids. Moreover, this discovery contributes to increasing the knowledge about little-studied species, since the Ajur_Neprilysin is the second neprilysin found in the venom from a mygalomorph spider.

Mercury and methylmercury content, fatty acids profile, and proximate composition of consumed fish in Cananéia, São Paulo, Brazil

Fifty three individuals of four most commonly consumed fish species by the Cananéia city population, in São Paulo, Brazil, were analyzedto determine total mercury (Total Hg) and methylmercury (MeHg) levels, as well as, proximate composition and fatty acid profile. Themuscle of three carnivorous species Centropomus parallelus (Fat snook), Macrodon ancylodon (King weakfish) and Micropogonias furnieri(Whitemouth croaker), and one planktivorous species Mugil platanus (Mullet) were analyzed. MeHg and Total Hg determinations wereperformed by Cold Vapour Atomic Absorption Spectrometry (CV AAS). Fatty acid profile was determined by gas chromatography (GC) whilst AOAC methods were used for proximate analysis. The total Hg results (interval) in wet weight basis were: Whitemouth croaker(114–442 μg kg-1), Fat snook (15-178 μg kg-1), King weakfi sh (12-100 μg kg-1) and Mullet (<10–25 μg kg-1), and none of the fish species exceeded the Brazilian legislation limits. MeHg values were below FAO/WHO (2007) recommendations. In nutritional terms, the resultsfor proximate composition for all four fish species proved to be an excellent protein source with very low lipid content as was expected. Fatty acids of all fish species were adequate. Total polyunsaturated fatty acid contents varied from 21.9% (Micropogonias furnieri) to26.4% (Mugil platanus). For the n-3 family, Macrodon ancylodon presented the highest value (20.9%) and Micropogonias furnieri thelowest one (15.8%). Mugil platanus (Mullet) species also showed good levels for all parameters analyzed and very low concentrations of contaminants, indicating it as a good nutritional choice in terms of risks and benefits.

Moléculas biologicamente ativas da hemolinfa de pupas de Lonomia obliqua

Os insetos formam um grupo grande e diverso de animais. Eles vivem em quase todos os ecossistemas do planeta e essa ampla distribuição tem estimulado a pesquisa por moléculas bioativas entre eles. Vários estudos têm sido realizados demonstrando a presença de substâncias farmacologicamente ativas na hemolinfa dos insetos. A Lonomia obliqua é um inseto de importância médica, pois na sua fase larval possui cerdas urticantes com toxina que causa efeitos hemorrágicos. O veneno da Lonomia é bastante estudado, sendo que muitos dos seus componentes foram isolados e caracterizados. Na hemolinfa da L. obliqua já foram identificadas algumas moléculas como a lonofibrase, que tem ação fibrinogenolítica, e uma proteína de alto peso molecular que estimula a produção de proteínas recombinantes...