As venomous animals, spiders use their chemical arsenal for prey capture or defence. Small neurotoxins target the central nervous system of their victims. While the toxins are intensively investigated, scientists at the LOEWE Centre for Translational Biodiversity Genomics (TBG) in Hesse, Germany, have turned their attention to the enzymes also contained in the complex venom cocktail. They discovered a large, previously overlooked diversity of these proteins that facilitate biochemical reactions. According to the researchers, these could be of great value for bioeconomic applications.

With around 52,000 species worldwide, spiders are particularly diverse and produce the most complex of all animal venoms: the venom of only a single species can contain more than 3,000 molecules. These belong mainly to the group of small neurotoxins and are used to overpower insects. A team of researchers from the LOEWE Centre TBG at the Fraunhofer Institute for Molecular Biology and Applied Ecology, branch of Bioresources (IME-BR) in Giessen, Germany, has now investigated the previously neglected components of spider venom and discovered something surprising. In their study, they show that in addition to neurotoxins the heavily investigated spider venom also contains a wide variety of enzymes. Their results have been published in the journal “npj Biodiversity”, which is part of the “Nature” group of journals.

“In the past, a few pioneering studies suggested the presence of enzymes in spider venoms, but a targeted search for them has never been carried out. We took on this task and systematically screened the raw data of all so far venom-wise analysed spiders for enzymes. We were able to show that there are in fact more than 140 different enzyme families in their venom,” explains study leader Dr. Tim Lüddecke, head of the Animal Venomics working group at the IME-BR and the Justus Liebig University in Giessen. “This means, among others, that we have dramatically underestimated the chemical diversity of spider venoms so far, as all calculations of complexity are based on the neurotoxins alone.”

According to the authors, the results of the work not only enable new research approaches to better understand the evolution and function of spider venoms, but also open new perspectives for their use. “Enzymes are key building blocks of the bioeconomy. They accelerate chemical reactions and are characterised by very low by-product formation, low energy consumption and biodegradability. They can therefore be used to create value in a highly sustainable way. Industry is therefore constantly looking for new sources of enzymes,” explains Josephine Dresler, PhD student in the working group and first author of the study. “Some of the enzymes we have identified could be used in detergents or waste management, for example, because of their fat-splitting or protein-degrading properties. They could make a significant contribution to a sustainable transformation there,” says Dresler.

The work of the Giessen scientists highlights the translational potential hidden in animal venoms, especially those of spiders. “So far, the spider venom community has focused exclusively on medical or agricultural applications. Our discovery opens up the possibility of establishing a completely new field of applied research,” explains Lüddecke. “But we are only at the beginning, as less than one per cent of all spider species have been studied for their venoms. I am confident that we will make more exciting discoveries in the remaining 99 per cent of the world's spider fauna!”