Empowered by a $1.2 million grant from the National Institutes of Health (NIH), Arizona State University scientist Wayne Frasch is deciphering how one of the world's smallest molecular motors works in living cells. In the process, he is also casting light on a physics puzzle that has perplexed scientists for more than 40 years.
Frasch, a professor in the School of Life Sciences, examines the Fo molecular motor, its mechanism of action and how it partners with the F1 motor as part of the FoF1 ATP synthase. At about 10 nanometers in diameter, each motor is 10,000 times smaller than the width of a piece of paper. In living things, Fo and F1 are attached by a common rotary axel that allows the two motors to work together and supply energy to cells in the form of adenosine triphosphate (ATP).
Research of nanoscale motors is not just complicated by size. Molecular motors operate via extremely small motions that occur on time scales that have been extraordinarily difficult to measure. The Fo molecular motor is also embedded in a living cell's lipid membrane, which is only two molecules thick. Adding to the experimental challenge is the fact that the molecular motors' rotational energy arises from the flow of protons, positively-charged atomic particles, across that membrane.
The Frasch lab is among only a few laboratories equipped to visualize how a single molecule of the Fo motor rotates. Frasch and his ASU College of Liberal Arts and Sciences colleagues have developed an experimental system that embeds the Fo motor in an artificial phospholipid bilayer laid down in nanodiscs, which help to stabilize the molecular complexes. Frasch's group then devised an imaging strategy, using gold nanorods attached to Fo to monitor the rotation of the single FoF1 molecules.
"Knowing more about these tiny, but extraordinarily efficient nearly 100 percent molecular motors offers an avenue to development new technologies, such as power sour
|Contact: Margaret Coulombe|
Arizona State University