Squid sucker ‘teeth’ are strong, stretchy

They look as though they belong in a B-grade horror film, but the rows of “teeth” in squid suckers do have a purpose. Squid feed on fish and crustaceans – which are fast, slippery and tough to get a grip on – so need sharp hooks to latch on and stay hooked without snapping off.

And it’s the teeth’s strong and stretchy properties that are so attractive to biomedical scientists, who look for new ways to grow tissue without using bone or artificial substances.

In research presented at the annual meeting of the Biophysical Society in Los Angeles this week, a team of researchers from Nanyang Technical University and A*STAR in Singapore unravel the molecular secrets of the teeth.

Some teeth are made entirely of a protein called “suckerin”. Previous research has deciphered the protein’s genetic code. But the latest work from Singapore shows the protein’s polymers, the building blocks of the protein, are linked in “beta-sheet” network, which give teeth their strength.

They also discovered the polymer networks are thermoplastic: when heated, they melt, and harden as they cool. Just like PVC plastic, suckerin is moldable and reusable.

Spider silk also forms beta-sheet configurations, “but silk proteins are difficult to produce and process”, says one of the researchers, Akshita Kumar from Nanyang Technical University.

This is because spider silk proteins are large compared to the smaller and simpler suckerin. And suckerin’s thermoplastic nature means they might be easier to manufacture in the lab, Kumar adds.

While far from being economically viable yet, the team plans to suss out the rest of the suckerin protein family – all 21 of them – and see which have properties best suited to biomedical scaffolding for reconstructive surgery, and others which might provide eco-friendly soft packaging.