How the bloodworm got its copper teeth
For a long time, scientists did not know how the bloodworm got its venomous copper teeth, but 20 years of studies have revealed how the creature builds the teeth using a special protein.
The bloodworm Glycera dibranchiata is an aggressive hunter that feeds on other seaworms and small crustacians. In order to hold on to its prey, the bloodworm extends its mouth part from its body, first paralysing its prey with venom from its teeth, then eating it alive.
A key role in this process is played by the four black venomous fangs located around the worm’s circular mouth. Not only do these four teeth represent a lethal weapon, these black venomous teeth are made mainly of copper. Yet for decades, experts have not been able to explain how they are created.
Scientists from the University of California have been studying the bloodworm for the past 20 years, and for a long time they believed that the worm’s copper content, which is high enough to kill most other small creatures, was a byproduct of water pollution.
But now they think that the worm collects the metal itself, and is able to build its copper teeth by means of a simple protein.
They have recently teased out the details of this process. The worm builds its teeth from a mixture of a protein, melanin (dark-coloured pigment responsible for their black colour), and the worm’s high concentrations of copper crystals. When it has collected sufficient copper in its body from ocean floor sediments, special proteins including the amino acid dihydroxyphenylalanine then activate to melt the metal particles into a viscous protein-rich liquid, separating it effectively from ocean water.
Using the copper as a catalyst, the worm converts the amino acid into melanin. Together with the special proteins, melanin fuses the copper with the worm’s jaws, forming the potent fangs.
Although the protein consists of two rather ordinary amino acids – glycine and histidine – it is so efficient that scientists are calling it a “multitasking protein”.
The scientists behind the discovery hope that the worm’s simple protein might be used to develop new and improved metal processing technologies. They think that the worm’s simple but highly efficient internal ‘laboratory’ could also inspire similar optimisation of production and materials within various different industries.