A Multiomics Approach Unravels New Toxins With Possible In Silico Antimicrobial, Antiviral, and Antitumoral Activities in the Venom of Acanthoscurria rondoniae

The Araneae order is considered one of the most successful groups among venomous animals in the world. An important factor for this success is the production of venoms, a refined biological fluid rich in proteins, short peptides and cysteine-rich peptides (CRPs). These toxins may present pharmacologically relevant biological actions, as antimicrobial, antiviral and anticancer activities, for instance. Therefore, there is an increasing interest in the exploration of venom toxins for therapeutic reasons, such as drug development. However, the process of peptide sequencing and mainly the evaluation of potential biological activities of these peptides are laborious, considering the low yield of venom extraction and the high variability of toxins present in spider venoms. Here we show a robust methodology for identification, sequencing, and initial screening of potential bioactive peptides found in the venom of Acanthoscurria rondoniae. This methodology consists in a multiomics approach involving proteomics, peptidomics and transcriptomics analyses allied to in silico predictions of antibacterial, antifungal, antiviral, and anticancer activities. Through the application of this strategy, a total of 92,889 venom gland transcripts were assembled and 84 novel toxins were identified at the protein level, including seven short peptides and 10 fully sequenced CRPs (belonging to seven toxin families). In silico analysis suggests that seven CRPs families may have potential antimicrobial or antiviral activities, while two CRPs and four short peptides are potentially anticancer. Taken together, our results demonstrate an effective multiomics strategy for the discovery of new toxins and in silico screening of potential bioactivities. This strategy may be useful in toxin discovery, as well as in the screening of possible activities for the vast diversity of molecules produced by venomous animals.

Rondonin an antifungal peptide from spider (Acanthoscurria rondoniae) haemolymph

Antimicrobial activities were detected in the haemolymph of the spider Acanthoscurrria rondoniae. A novel antifungal peptide, rondonin, was purified by reverse phase high performance liquid chromatography (RP-HPLC). Rondonin has an amino acid sequence of IIIQYEGHKH and a molecular mass of 1236.776 Da. This peptide has identity to a C-terminal fragment of the "d" subunit of haemocyanin from the spiders Eurypelma californicum and Acanthoscurria gomesiana. A synthetic peptide mimicking rondonin had identical characteristics to those of the isolated material, confirming its sequence. The synthetic peptide was active only against fungus. These data led us to conclude that the antifungal activity detected in the plasma of these spiders is the result of enzymatic processing of a protein that delivers oxygen in the haemolymph of many chelicerate. Several studies have suggested that haemocyanins are involved in the arthropod immune system, and the activity of this haemocyanin fragment reinforces this idea.