The Strength of Binding of the Weakly-Binding Crossbridge Created by Sulfhydryl Modification has very Low Calcium Sensitivity

  • Vincent A. Barnett
  • Mark Schoenberg
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 332)


The acto-subfragment-1*ATP state is an important intermediate in the Ca-activated acto-S1 ATPase reaction, suggesting that the myosin• ATP crossbridge seen in muscle fibers similarly may be an important intermediate in the contractile cycle. Treatment of muscle fibers with either para-phenylenedimaleimide (pPDM) or N-phenylmaleimide (NPM) alters the myosin crossbridges so that they bind to the actin filament with about the same affinity as the myosin•ATP crossbridge. Additionally, the treated crossbridges and the myosin•ATP crossbridge have virtually identical attachment and detachment rate constants. Thus the treated crossbridges appear to be reasonable analogues of the weakly-binding myosin•ATP crossbridges of relaxed fibers and studies of the treated fibers may shed some light on the behavior of the physiologically important myosin•ATP crossbridge. We have examined the influence of Ca2+ on the binding and rate constants of pPDM- and NPM-treated weakly-binding crossbridges. In agreement with earlier solution studies, we found almost no Ca-sensitivity of the binding of pPDM- or NPM-treated crossbridges.


Calcium Sensitivity Cross Bridge Contracting Solution Predominant State Attached Crossbridges 
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  1. 1.
    Greene, L.E. & Eisenberg, E. Proc. Natl Acad. Sci. USA. 77, 2616–2620 (1980).PubMedCrossRefGoogle Scholar
  2. 2.
    Brenner, B., Yu, L.C., Greene, L.E., Eisenberg, E. & Schoenberg, M. Biophys. J. 50, 1101–1108 (1986).PubMedCrossRefGoogle Scholar
  3. 3.
    Chalovich, J. M. & Eisenberg, E. J. Biol. Chem. 252, 2432–2437 (1982).Google Scholar
  4. 4.
    Marston, S.B. & Tregear, R.T. Nature 235, 23–24 (1972).Google Scholar
  5. 5.
    Siemankowski, R.F., Wiseman, M.D. & White, H.D.. Proc. Natl. Acad. Sci. USA. 82, 658–662 (1985).PubMedCrossRefGoogle Scholar
  6. 6.
    Dantzig, J.A., Walker, J.W., Trentham, D.R. & Goldman, Y.E. Proc. Natl Acad. Sci. USA 82, 658–662 (1988).Google Scholar
  7. 7.
    Schoenberg, M. Adv. Exp. Med. Biol. 226, 189–202 (1988).PubMedGoogle Scholar
  8. 8.
    Schoenberg, M. Biophys. J. 60, 690–696 (1991).PubMedCrossRefGoogle Scholar
  9. 9.
    Wells, J.A. & Yount, Y.G.. Proc. Natl Acad. Sci. USA. 76, 4966–4970 (1979).PubMedCrossRefGoogle Scholar
  10. 10.
    Duong, A. & Reisler, E.. Biochemistry 28, 3502–3509 (1989).PubMedCrossRefGoogle Scholar
  11. 11.
    Chalovich, J.M., Greene, L.E. & Eisenberg, E. Proc. Natl Acad. Sci. USA. 80, 4909–4913 (1983).PubMedCrossRefGoogle Scholar
  12. 12.
    Chaen, S., Shimada, M. & Sugi, H. J. Biol. Chem. 261, 13632–13636 (1986).PubMedGoogle Scholar
  13. 13.
    Barnett, V.A., Ehrlich, A. & Schoenberg, M. Biophys. J. 61, 358–367 (1992).PubMedCrossRefGoogle Scholar
  14. 14.
    Schoenberg, M. Biophys. J. 54, 135–148 (1988).PubMedCrossRefGoogle Scholar
  15. 15.
    Schoenberg, M. Biophys. J. 48, 467–475 (1985).PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1993

Authors and Affiliations

  • Vincent A. Barnett
    • 1
  • Mark Schoenberg
    • 1
  1. 1.Laboratory of Physical BiologyNational Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of HealthBethesdaUSA

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