BY MARIA BURKE
Slime ejected by a particular family of worms could inspire the next generation of recyclable bioplastics, according to Australian researchers.
Velvet worms – small caterpillar-like creatures found in humid forests of the southern hemisphere – produce a protein-based liquid adhesive or slime which rapidly hardens into strong fibres allowing the worms to capture prey and defend themselves. The fibres dissolve in water and can be reconstituted. However, the molecular mechanism behind this reversibility has remained unclear until now.
Using protein sequencing and AI-driven structure prediction (AlphaFold), a team led by Matthew Harrington of McGill University, Canada, compared the slime from two distantly related subgroups of velvet worms. They discovered a group of leucine-rich repeat (LRR) proteins in slime from both groups (Proceedings of the National Academy of Sciences, 2025, DOI: 10.1073/pnas.2416282122).
The LRR proteins, which are known for their roles in immunity and development, had adopted a horseshoe structure reminiscent of cell receptors in the immune system. During fibre formation, the researchers believe dimerised LRR proteins link the large structural proteins, which are the primary building blocks of velvet worm slime. This function in the ‘ubiquitously occurring’ LRR – that of processing a biological material – has not been described before, they say.
‘Nature has already figured out a way to make materials that are both strong and recyclable,’ says Harrington. ‘By decoding the molecular structure of velvet worm slime, we’re now one step closer to replicating that efficiency for the materials we use every day. Obviously, a plastic bottle that dissolves in water would have limited use, but by adjusting the chemistry of this binding mechanism, we can get around this issue.’
The team’s next challenge is to experimentally verify the binding interactions and explore whether the principle can be adapted to fabricate fully recyclable biopolymeric materials.
Visit Blog
