Buccitoxins and muritoxins: Conotoxin-like peptides in non-conoidean venoms revealed with a novel bioassay
Using a novel field-deployable bioassay (LIMCALA) and machine learning analysis, researchers identified conotoxin-like myotoxins, termed "buccitoxins" and "muritoxins," in the salivary venoms of non-conoidean whelks and murexes, suggesting a broader evolutionary distribution of these pharmacologically promising peptides.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of a preprint that has not been peer-reviewed. It is not medical advice. Do not make health decisions based on this content. Read full disclaimer
For decades, scientists have looked to the ocean's most dangerous predators for cures. Among them, the cone snail holds a special place. These marine snails hunt with a harpoon-like tooth, injecting a complex cocktail of tiny protein fragments called peptides. Some of these peptides are so precise in how they lock onto nerve cells that they have become the basis for powerful painkillers and are being studied for treating cancer. Because these molecules are so effective, researchers have spent years hunting for similar compounds in other sea creatures, hoping to find new medicines hidden in the vast biodiversity of the deep. The challenge has always been that identifying these tiny, complex molecules usually requires massive, expensive laboratory machines that cannot be easily moved to a research boat or a remote field station.
A new study by Luke Levensaler suggests that the search for these valuable molecules might need to expand beyond the cone snail's closest relatives. The research focuses on two groups of predatory sea snails that are not cone snails: the whelks and the murexes. While cone snails use a harpoon to deliver venom, these other snails inject toxins through their saliva, much like some land-based lizards and shrews do. The study tested three specific species: the Lightning Whelk, the Pear Whelk, and the Apple Murex. The central question was whether these non-cone snails produce venom peptides that share the same structural blueprint as the famous cone snail toxins. If they do, it would mean a much wider pool of potential medicines exists in the ocean than previously thought.
To answer this, the researcher collected venom samples from the salivary glands of these snails. The process involved carefully dissecting the animals to access the glands that produce the venom, then extracting the fluid. Because the goal was to analyze the structure of the proteins without needing a high-end mass spectrometer, a new testing method was developed. This method, called the LIMCALA assay, works by attaching a chemical tag to the sulfur-rich parts of the venom proteins. Sulfur is a key ingredient in the structure of these toxins, acting like a set of molecular staples that hold the protein in its specific shape. The assay uses a common enzyme that changes color when it reacts with these tagged proteins, allowing the researcher to measure the light absorption of the sample across a wide range of wavelengths. This creates a unique spectral fingerprint for each venom sample.
Once the fingerprints were captured, they were fed into a custom computer program designed to compare the patterns. The program measured how closely the venom from the whelks and murexes matched the pattern of a known, high-value cone snail toxin used as a standard reference. The results were striking. The venom from the Pear Whelk showed a very high degree of similarity to the cone snail toxin, with a match score of over 86 percent. The Apple Murex also showed a strong match at roughly 82 percent. Even the Lightning Whelk, which had the lowest score of the three, still showed a statistically significant similarity of nearly 65 percent. These numbers were not random; the computer ran thousands of random permutations to ensure the matches were real, and the results remained consistent.
The study suggests that these snails produce their own versions of cone snail toxins, which the author has named "buccitoxins" for the whelks and "muritoxins" for the murexes. This finding challenges the previous assumption that only cone snails and their immediate cousins produce these specific, highly structured peptides. The data indicates that the Lightning Whelk and the Apple Murex, despite being from different evolutionary families, both possess venom components that look and behave very much like the famous cone snail toxins. Interestingly, the Apple Murex, which was expected to be more similar to cone snails because of its evolutionary history, actually scored lower than the Pear Whelk, suggesting that the specific diet or environment of the snails might influence their venom more than their family tree does.
While the study does not yet prove that these new toxins can cure diseases, it strongly suggests that they share the same fundamental building blocks as the cone snail toxins that are already being used in medicine. The research provides a new, portable way to screen for these molecules without needing expensive equipment, opening the door for future studies to isolate and test them in detail. The author notes that the next steps would involve using traditional, high-precision machines to confirm the exact chemical structure of these peptides and to test them on living cancer cells. For now, the work confirms that the ocean's pharmacy may be much larger than anyone realized, hiding valuable compounds in the saliva of common sea snails that were previously overlooked.
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