A species of kamikaze termite in French Guiana carries a backpack containing volatile poison that can explode at a moment’s notice to protect its nest.
Suicide termites have evolved a unique defense mechanism: carrying backpacks filled with liquid poison that can be triggered to explode, poisoning their enemies in the process. Now, scientists are uncovering the mystery of how they carry this deadly backpack around and detonate it when needed. Live Science September 3 news.
In 2012, researchers discovered worker termites. Neocapritermes taracua Older termites are equipped with blue-spotted backpacks that explode when they are threatened. N. taracua workers have a special gland in their abdomen that gradually secretes the blue laccase enzyme BP76 into their back pouches. As they age, the termites accumulate backpacks of these blue crystals containing copper. When threatened, the workers rub their bodies, mixing the enzyme with secretions in their salivary glands. The result is a sticky liquid rich in the highly toxic compound benzoquinone that can paralyze or kill predators.
However, the researchers wondered how BP76 could maintain its solid state while stored on the back of termites, while also being ready to react immediately when rubbed. The new study was published in the journal Structure unraveled that mystery by providing the first high-resolution crystal structure of the enzyme. The three-dimensional structure of the enzyme revealed that BP76 has multiple stabilization mechanisms, according to team leader Jana Škerlová of the Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences. The enzyme is folded compactly, which helps prevent it from degrading over time. Another layer of protection comes from sugar molecules attached to the protein, forming a protective shield that stabilizes the structure.
One of the more interesting features of BP76 is the unusually strong chemical bond between two amino acids, lysine and cysteine, near the enzyme’s active site. This bond is not only common among enzymes, but also plays a key role in maintaining the structure of BP76, especially when the enzyme is stored in solid form on the termites’ backs. The bond acts like a locking mechanism, ensuring that the enzyme can maintain its shape and function fully, ready to deploy at a moment’s notice when the termites need to defend their nest.
The ability to store and accumulate enzymes consistently as termites age is important for nest protection. Previous research has suggested that as termite jawbones erode over time, older termites may not be as efficient at foraging or maintaining their nests as younger ones. With their explosive backpacks, older termites provide a last-ditch, lethal means of keeping the nest safe.