Enlightening the toxinological dark matter of spider venom enzymes.

Spiders produce highly adapted venoms featuring a complex mixture of biomolecules used mainly for hunting and defense. The most prominent components are peptidic neurotoxins, a major focus of research and drug development, whereas venom enzymes have been largely neglected. Nevertheless, investigation of venom enzymes not only reveals insights into their biological functions, but also provides templates for future industrial applications. Here we compared spider venom enzymes validated at protein level contained in the VenomZone database and from all publicly available proteo-transcriptomic spider venom datasets. We assigned reported enzymes to cellular processes and known venom functions, including toxicity, prey pre-digestion, venom preservation, venom component activation, and spreading factors. Our study unveiled extensive discrepancy between public databases and publications with regard to enzyme coverage, which impedes the development of novel spider venom enzyme-based applications. Uncovering the previously unrecognized abundance and diversity of venom enzymes will open new avenues for spider venom biodiscovery.