Super Rubber Made in Leaps and Bounds

If you supersized a flea to the height of a fully grown man, and assumed it could actually lift its own weight, the scratchy little critter would be able to leap a tall building. But, fleas aren't that size and can jump one hundred times their height only because they are so small. That said, if you shrank a man to the size of a flea, he'd struggle to keep up in the high jump trials.

A solution to this apparent dichotomy has been laid bare by Australian scientists who have more than scratched the surface to synthesise a polymer based on an elastic protein called resilin that endows the flea with such record-breaking leaping prowess. Resilin is produced by numerous other species, such as fruitflies and cicadas who use it to make their chirping sounds. Now, Christopher Elvin and colleagues at the CSIRO Livestock Industries, in St Lucia, Australia, have produced a synthetic version of the natural polymer, which they say is extremely rubbery and resilient. The team adopted a biotech strategy to synthesising resilin.

Elvin's biotech approach to resilin involved transferring from fruitflies the gene thought to be responsible for generating the elastic part of resilin, and incorporating it into lab microbe Escherichia coli. Fermentation led to E coli expressing the fruitfly gene and producing large quantities of the elastic peptide. The team could then extract it and treat it with light to cure it into the final rubbery product.

The researchers found that a strip of the synthetic resilin can be stretched to over three times its original length without breaking. The team suggests that the material could be useful as a replacement for similar materials in the human body, such as the elastin in arteries.

Nature 2005, 437, 999-1002; http://dx.doi.org/10.1038/nature04085