Nanomedicine: Nanotechnology, Biology and Medicine
Volume 6, Issue 4 , Pages 510-515, August 2010

Time-dependent measure of a nanoscale force-pulse driven by the axonemal dynein motors in individual live sperm cells

  • Michael J. Allen, PhD

      Affiliations

    • Biometrology, Alameda, California, USA
    • Corresponding Author InformationCorresponding author: Center for Nanomedicine, Section of Pulmonary and Critical Care, The University of Chicago, Chicago, Ill 60637, USA.
    • ,
  • Robert E. Rudd, PhD

      Affiliations

    • Condensed Matter and Materials Division, Lawrence Livermore National Laboratory, Livermore California, USA
    • ,
  • Mike W. McElfresh, PhD

      Affiliations

    • Department of Physics, University of California, Davis, California, USA
    • ,
  • Rod Balhorn, PhD

      Affiliations

    • Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, California, USA

Received 8 July 2009; accepted 16 December 2009. published online 07 January 2010.

Abstract 

Nanoscale mechanical forces generated by motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces is important to developing motile biomimetic nanodevices powered by biological motors for nanomedicine. Axonemal dynein motors positioned inside the sperm flagellum drive microtubule sliding and give rise to rhythmic beating. This force-generating action pushes the sperm cell through viscous media. Here we report new nanoscale information on how the propulsive force is generated by the sperm flagellum and how this force varies over time. Using a modified atomic force microscope, single-cell recordings reveal discrete ∼50-ms pulses oscillating with amplitude 9.8 ± 2.6 nN independent of pulse frequency (3.5–19.5 Hz). The average work carried out by each cell is 4.6 × 10-16 J per pulse, equivalent to the hydrolysis of ∼5500 molecules of adenosine triphosphate. The mechanochemical coupling at each active dynein head is ∼2.2 pN per adenosine triphosphate molecule and ∼3.9 pN per dynein arm.

From the Clinical Editor

In this paper, nanoscale mechanical forces generated by axonemal dynein motors derived from sperm flagellum are examined and reported. These motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces is important to developing motile biomimetic nanodevices powered by biological motors for nanomedicine.

Key words: Cantilever, Flagellum, Motility, Sensor, Propulsion

 

 This work was performed through support from Biometrology to M.J.A.; and to R.E.R., M.W.M., and R.B. from the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

PII: S1549-9634(10)00003-1

doi:10.1016/j.nano.2009.12.003

Nanomedicine: Nanotechnology, Biology and Medicine
Volume 6, Issue 4 , Pages 510-515, August 2010

Article Tools

* Image Usage & Resolution