Letter | Published:

Limitations in the use of actomyosin threads as model contractile systems

Naturevolume 287pages338340 (1980) | Download Citation

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Abstract

Recent studies have suggested that actomyosin threads may provide a useful model for studying the properties of contractile systems1–3. The development of highly sensitive positional feedback transducers has enabled the properties of these threads to be measured reproducibly1. Potential applications include such systems as ventricle, smooth muscle and non-muscle preparations, from which it is difficult to obtain suitable fibres for mechanical studies. In addition, studies with chemically modified myosins may provide new insights into the relationships between the biochemical and mechanical events in the cross-bridge cycle. However, there are indications that the mechanical properties of actomyosin threads differ from those of intact fibres in several important respects. For example, contraction velocity is proportional to isometric tension in threads2, but is independent of filament density in intact fibres4. We have now determined the force–velocity characteristics of actomyosin threads prepared from muscles with known differences in their physiological contraction velocities. No direct relationships could be found between the velocity characteristics of the threads and those of intact muscle. We conclude that the measured velocities of threads reflect properties of the actomyosins other than cross-bridge cycling times, thus severely limiting the usefulness of this technique for comparative purposes.

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References

  1. 1

    Crooks, R. & Cooke, R. J. gen. Physiol. 69, 37–55 (1977).

  2. 2

    Cooke, R. & Franks, K. E. J. molec. Biol. 120, 361–373 (1978).

  3. 3

    Matsumura, F., Yoshimoto, Y. & Kamiya, N. Nature 285, 169–171 (1980).

  4. 4

    Josephson, R. K. J. exp. Zool. 194, 135–154 (1975).

  5. 5

    Lehman, W. & Szent-Györgyi, A. G. J. gen. Physiol. 66, 1–30 (1975).

  6. 6

    Spudich, J. A. & Watt, S. J. biol. Chem. 246, 4866–4871 (1971).

  7. 7

    Barany, M. & Close, R. I. J. Physiol., Lond. 213, 455–474 (1971).

  8. 8

    Flitney, F. W. & Johnston, I. A. J. Physiol., Lond. 295, 49P–50P (1979).

  9. 9

    Lännergren, J. J. Physiol., Lond. 283, 501–521 (1978).

  10. 10

    Close, R. J. Physiol, Lond. 204, 331–346 (1969).

  11. 11

    Barany, M. J. gen. Physiol. 50, Suppl. 197–216 (1967).

  12. 12

    D'Haese, J. & Komnick, H. Z. Zellforsch. 134, 411–426, 427–434 (1972).

  13. 13

    Josephs, R. & Harrington, W. F. Biochemistry 5, 3474–3487 (1966).

  14. 14

    Kaminer, B. & Bell, A. L. J. molec. Biol. 20, 391–401 (1966).

  15. 15

    Pinset-Härström, I. & Truffy, J. J. molec. Biol. 134, 173–188 (1979).

  16. 16

    Pinset-Härström, I. & Whalen, R. G. J. molec. Biol. 134, 189–197 (1979).

  17. 17

    Syrovy, I. Int. J. Biochem. 10, 383–389 (1979).

  18. 18

    Itzhaki, R. F. & Gill, D. M. Analyt. Biochem. 9, 401–410 (1964).

  19. 19

    Hill, A. V. Proc. R. Soc. B126, 136–195 (1938).

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  1. Department of Physiology, University of St Andrews, St Andrews, Fife, KY16 9TS, UK

    • John D. Altringham
    • , Paul H. Yancey
    •  & Ian A. Johnston

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https://doi.org/10.1038/287338a0

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