Unlocking the secrets of silk

Biologists at the

, have uncovered the molecular structure of the gene for the protein that female spiders use to make their silken egg cases. The discovery will help biotechnologists develop applications for spider silk and will shed light on spider evolution.

Assistant Professor of Biology Cheryl Hayashi and postdoctoral researcher Jessica Garb characterised the variants of the protein (TuSp1) used by 12 species of spiders to make egg-case silk. They found strong similarities in the lengthy amino acid sequences of the proteins among species that diverged at least 125 million years ago.

The findings are important, in part, because the mechanical properties of the various types of spider silk, their elasticity, tensile and breaking strength, are dependent on the sequence of amino acids that form the silk proteins.

“Collectively, spider silks are some of the toughest natural fibres known,” Hayashi said. “Imagine a fabric made from such a substance? It would be incredibly strong, flexible and ultimately, biodegradable.”