14 DAY TRIAL // Researchers from Duke University and the Howard Hughes Medical Institute found that a component of many proteins constitutes one of the most powerful and resilient molecular "springs" in nature.
This discovery might offer new clues on the mechanical processes within the living cell and pave the way for the nanoscale shock absorbers" or "gate-opening springs" in tiny nanomachines.
The team says that the protein components, called "ankyrin repeats," which 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.
"Whereas other known proteins can act like floppy springs, ankyrin molecules behave more like steel. After repeated stretching, the molecules immediately refold themselves, retaining their shape and strength," said Piotr Marszalek, professor of mechanical engineering and materials science at the Duke Pratt School of Engineering.
"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. It's the equivalent of un-boiling an egg," added HHMI investigator Vann Bennett, professor of cell biology at Duke University Medical Center.
Ankyrin repeats consist of tandem modules of about 33 amino acids, have different lengths and are found in more than 400 human proteins.
For example, ankyrin repeats are found in association with specialized hair cells of the inner ear, where they play a critical role in converting sound into an electrical signal that can be transmitted to the brain, a process known as mechanotransduction.
Ankyrin proteins also coordinate the ion channels and transporters that control the beating of the heart. In 2004, Bennett's team linked mutations in the gene ankyrin-B to an inherited cardiac arrhythmia syndrome that can lead to sudden death.