Kamikaze termites in French Guiana deploy explosive backpacks for defense

In French Guiana, researchers have uncovered a remarkable defense mechanism employed by older Neocapritermes taracua worker termites. These termites carry specialized backpacks filled with a toxic liquid that can be detonated when threatened, effectively poisoning their predators. The study, published on August 15 in the journal Structure, reveals the intricate structure of the enzyme blue laccase BP76, which is crucial for this explosive defense. The enzyme is stored in a solid state on the termites' backs, thanks to a unique three-dimensional structure that prevents degradation over time. The enzyme's stability is enhanced by sugar molecules that form a protective shield, while a rare chemical bond between amino acids lysine and cysteine plays a vital role in maintaining its structure. This bond acts as a locking mechanism, ensuring that the enzyme remains functional and ready for immediate use when the termite faces danger. As termites age, they accumulate these toxic backpacks, allowing them to specialize in defense rather than foraging or nest maintenance, which may become less effective due to dull mandibles. This adaptation highlights the evolutionary strategies termites have developed to protect their colonies. The ability to store and deploy a potent chemical weapon is critical for the survival of the colony, especially as older workers transition from active roles to defensive ones. The findings shed light on the complex biological processes that enable these termites to thrive in their environment. Overall, the research not only solves the mystery of how these termites manage their explosive defense but also emphasizes the importance of understanding the structural biology of enzymes in ecological adaptations.