Spacing Changes in the Actin and Myosin Filaments during Activation, and Their Implications

  • Hugh E. Huxley
  • Alex Stewart
  • Tom Irving
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 453)


Small but important axial spacing changes have been found to occur in the X-ray reflections from both the actin and myosin filaments when a muscle changes from the resting state to a state of isometric contraction1,2. The overall spacing change in the actin is an increase of approximately 0.25–0.30%, measured on the first actin meridional reflection at 27.3 Å. This implies a length increase of approximately 2.5–3.0 nm in the actin filaments in each half-sarcomere. This is an appreciable fraction of the total compliance measured in quick release experiments3, and therefore has a considerable effect on their interpretation.




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  1. 1.
    Huxley, H.E., Stewart, A., Sosa, H. & Irving, T. Biophys. J. 67, 2411–2421 (1994).PubMedCrossRefGoogle Scholar
  2. 2.
    Wakabayashi, K.. et al. Biophys. J. 67, 2422–2435 (1994).PubMedCrossRefGoogle Scholar
  3. 3.
    Ford, L.E., Huxley, A.F. & Simmons, R.M.J. Physiol. (Lon.) 269, 441–515 (1977).Google Scholar
  4. 4.
    Finer, J.T., Simmons, R.M. & Spudich, J.A. Nature 368, 113–119 (1994).PubMedCrossRefGoogle Scholar
  5. 5.
    Molloy, J.E., Buras, J.E., Kendrick-Jones, J. & White, D.C.S. Nature 378, 209–212 (1995).PubMedCrossRefGoogle Scholar
  6. 6.
    Huxley, H.E., Faruqi, A.R., Kress, M., Bordas, J. & Koch, M.H.J. J. Mol. Biol. 158, 637–684 (1982).PubMedCrossRefGoogle Scholar
  7. 7.
    Bordas, J., et al. J. Muscle Res. & Cell Motil. 14, 311–324 (1993).CrossRefGoogle Scholar
  8. 8.
    Huxley, H.E., Simmons, R.M. & Faruqi, A.R. Biophys. J. 55, 12a (1989).Google Scholar
  9. 9.
    Diakun, G., Harries, J., Lowy, J., Svensson, A. & Towns-Andrews, E. J. Muscle Res. Cell Motil. 15, 319–348 (1994).PubMedGoogle Scholar

Copyright information

© Plenum Press, New York 1998

Authors and Affiliations

  • Hugh E. Huxley
    • 1
  • Alex Stewart
    • 1
  • Tom Irving
    • 2
  1. 1.Rosenstiel Basic Medical Sciences Research CenterBrandeis UniversityWalthamUSA
  2. 2.BioCAT, Department BCPSIllinois Institute of TechnologyChicatoUSA

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