Mapping the architecture of animal toxin systems by mass spectrometry imaging

Animal toxins are proteins, peptides or metabolites that cause negative effects against predators, prey or competitors following contact or injection. They work by interacting with enzymes, receptors and other targets causing pain, debilitation or leading even to death. Their biological significance and pharmacological effects in humans make them interesting to researchers, but much remains to be learned about their mechanisms of action, storage, tissue-specific distribution and maturation. Mass spectrometry imaging (MSI), a technique that determines the spatial distribution of molecules based on their molecular mass, is uniquely positioned to answer these key questions and pioneering studies have already confirmed its potential impact on the field of zootoxinology. We provide the first comprehensive review of MSI as a means to study animal toxins, the lessons learned thus far, and potential future applications. This fills an important gap in the literature and will facilitate future work on the structure, function, evolutionary history and medical uses of animal toxins.