Local Nanomechanical Motion of the Cell Wall of Saccharomyces cerevisiae
Andrew E. Pelling,
Sadaf Sehati,
Edith B. Gralla,
Joan S. Valentine,
James K. Gimzewski*
We demonstrate that the cell wall of living Saccharomyces cerevisiae (baker's yeast) exhibits local temperature-dependent nanomechanical motion at characteristic frequencies. The periodic motions in the range of 0.8 to 1.6 kHz with amplitudes of
3 nm were measured using the cantilever of an atomic force microscope (AFM). Exposure of the cells to a metabolic inhibitor causes the periodic motion to cease. From the strong frequency dependence on temperature, we derive an activation energy of 58 kJ/mol, which is consistent with the cell's metabolism involving molecular motors such as kinesin, dynein, and myosin. The magnitude of the forces observed (
10 nN) suggests concerted nanomechanical activity is operative in the cell.
Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095, USA.
* To whom correspondence should be addressed. E-mail: gim{at}chem.ucla.edu.