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

Abstract

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.

Keywords:

• Avicularia juruensis
• spider
• venom
• neprilysin
• casein
• metalloendopeptidase

Acknowledgements

We would like to thank MSc Thiago de Jesus Oliveira for his help in the maintenance of the bioterium where the spiders used in this study were kept. Mariana Salgado Loureiro de Caldas Morone and Ismael Feitosa Lima for their support in the transcriptomic and mass spectrometry analysis, respectively, and PhD Daniela Cajado de Oliveira Souza Carvalho for helping to correct the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001, as well as by the Research Support Foundation of the State of São Paulo [FAPESP/CeTICS - grant No. 2013/07467–1] and the Brazilian National Council for Scientific and Technological Development [CNPq - grant No. 472744/2012–7].