The team's findings were published in an advanced online publication of Nature on Jan. 15, 2006.
The finding that the protein components, called "ankyrin repeats," exhibit such unprecedented elastic properties could lead to a new understanding of how organisms, including humans, sense and respond to physical forces at the cellular level, the researchers said. The nanometer-sized springs are also ideal candidates for building biologically-inspired springy nanostructures and nanomaterials with an inherent ability to self-repair, they reported. A nanometer is one billionth of a meter.
"Whereas other known proteins can act like floppy springs, ankyrin molecules behave more like steel," said Piotr Marszalek, professor of mechanical engineering and materials science at the Duke Pratt School of Engineering. "After repeated stretching, the molecules immediately refold themselves, retaining their shape and strength."
"The fully extended molecules not only bounce back to their original shape in real time, but they also generate force in the process of this rapid refolding ?something that had never been seen before," added HHMI investigator Vann Bennett, professor of cell biology at Duke University Medical Center. "It's the equivalent of un-boiling an egg."
Marszalek and Bennett are participants in the Duke University Center for Biologically Inspired Materials and Material Systems. The research was supported by Duke University and the National Science Foundation.