Skip to main content
PMC home page
Biophysical Journal logoLink to Biophysical Journal
. 1982 Aug;39(2):221–227. doi: 10.1016/S0006-3495(82)84511-6

Three-dimensional disorder of dipolar probes in a helical array. Application to muscle cross-bridges.

R A Mendelson, M G Wilson
PMCID: PMC1328935  PMID: 6288134

Abstract

Fluorescence polarization and EPR experiments on azimuthally randomized helices bearing extrinsic (dipolar) probes yield information about the axial orientation and order of the probes. If the orientation of the probe on the structure bearing it is known and disorder is absent, the orientation of the structure may be ascertained. For cases where less probe orientation information is available and/or disorder is present, the available structural information is correspondingly reduced. Here we examine the available data on probes attached to cross-bridges in muscle fibers: four plausible cases of three-dimensional cross-bridge disorders are numerically modeled muscle in states of rigor and relaxation. In rigor, where the reported probe disorder is small (Thomas and Cooke, 1980), it was found that the cross-bridge disorder was also small. On the other hand, for the relaxed state where the probes are found to be completely disordered, the cross-bridges may have a considerable amount of order. This possibility is in concert with the results of x-ray diffraction, in which the presence of well-developed myosin-based layer lines indicates considerable order in relaxed muscle.

Full text

PDF
221

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Cooke R., Franks K. All myosin heads form bonds with actin in rigor rabbit skeletal muscle. Biochemistry. 1980 May 13;19(10):2265–2269. doi: 10.1021/bi00551a042. [DOI] [PubMed] [Google Scholar]
  2. Cooke R. Stress does not alter the conformation of a domain of the myosin cross-bridge in rigor muscle fibres. Nature. 1981 Dec 10;294(5841):570–571. doi: 10.1038/294570a0. [DOI] [PubMed] [Google Scholar]
  3. Huxley H. E., Brown W. The low-angle x-ray diagram of vertebrate striated muscle and its behaviour during contraction and rigor. J Mol Biol. 1967 Dec 14;30(2):383–434. doi: 10.1016/s0022-2836(67)80046-9. [DOI] [PubMed] [Google Scholar]
  4. Huxley H. E. The mechanism of muscular contraction. Science. 1969 Jun 20;164(3886):1356–1365. doi: 10.1126/science.164.3886.1356. [DOI] [PubMed] [Google Scholar]
  5. Lovell S. J., Harrington W. F. Measurement of the fraction of myosin heads bound to actin in rabbit skeletal myofibrils in rigor. J Mol Biol. 1981 Jul 15;149(4):659–674. doi: 10.1016/0022-2836(81)90352-1. [DOI] [PubMed] [Google Scholar]
  6. Magid A., Reedy M. K. X-ray diffraction observations of chemically skinned frog skeletal muscle processed by an improved method. Biophys J. 1980 Apr;30(1):27–40. doi: 10.1016/S0006-3495(80)85074-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Mendelson R. A., Morales M. F., Botts J. Segmental flexibility of the S-1 moiety of myosin. Biochemistry. 1973 Jun 5;12(12):2250–2255. doi: 10.1021/bi00736a011. [DOI] [PubMed] [Google Scholar]
  8. Mendelson R., Cheung P. H. Intrinsic segmental flexibility of the S-1 moiety of myosin using single-headed myosin. Biochemistry. 1978 May 30;17(11):2139–2148. doi: 10.1021/bi00604a018. [DOI] [PubMed] [Google Scholar]
  9. Mendelson R., Kretzschmar K. M. Structure of myosin subfragment 1 from low-angle X-ray scattering. Biochemistry. 1980 Aug 19;19(17):4103–4108. doi: 10.1021/bi00558a031. [DOI] [PubMed] [Google Scholar]
  10. Reedy M. K., Holmes K. C., Tregear R. T. Induced changes in orientation of the cross-bridges of glycerinated insect flight muscle. Nature. 1965 Sep 18;207(5003):1276–1280. doi: 10.1038/2071276a0. [DOI] [PubMed] [Google Scholar]
  11. Rome E. Relaxation of glycerinated muscle: low-angle x-ray diffraction studies. J Mol Biol. 1972 Mar 28;65(2):331–345. doi: 10.1016/0022-2836(72)90285-9. [DOI] [PubMed] [Google Scholar]
  12. Taylor K. A., Amos L. A. A new model for the geometry of the binding of myosin crossbridges to muscle thin filaments. J Mol Biol. 1981 Apr 5;147(2):297–324. doi: 10.1016/0022-2836(81)90442-3. [DOI] [PubMed] [Google Scholar]
  13. Thomas D. D., Cooke R. Orientation of spin-labeled myosin heads in glycerinated muscle fibers. Biophys J. 1980 Dec;32(3):891–906. doi: 10.1016/S0006-3495(80)85024-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Thomas D. D., Ishiwata S., Seidel J. C., Gergely J. Submillisecond rotational dynamics of spin-labeled myosin heads in myofibrils. Biophys J. 1980 Dec;32(3):873–889. doi: 10.1016/S0006-3495(80)85023-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Thomas D. D., Seidel J. C., Hyde J. S., Gergely J. Motion of subfragment-1 in myosin and its supramolecular complexes: saturation transfer electron paramagnetic resonance. Proc Natl Acad Sci U S A. 1975 May;72(5):1729–1733. doi: 10.1073/pnas.72.5.1729. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Tregear R. T., Mendelson R. A. Polarization from a helix of fluorophores and its relation to that obtained from muscle. Biophys J. 2009 Jan 1;15(5):455–467. doi: 10.1016/S0006-3495(75)85830-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Yanagida T. Angles of nucleotides bound to cross-bridges in glycerinated muscle fiber at various concentrations of epsilon-ATP, epsilon-ADP and epsilon-AMPPNP detected by polarized fluorescence. J Mol Biol. 1981 Mar 15;146(4):539–560. doi: 10.1016/0022-2836(81)90046-2. [DOI] [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES