Skip to main content
NCBI home page
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1985 Sep 1;101(3):830–837. doi: 10.1083/jcb.101.3.830

Structural changes that occur in scallop myosin filaments upon activation

PMCID: PMC2113694  PMID: 4040918

Abstract

Myosin filaments isolated from scallop striated muscle have been activated by calcium-containing solutions, and their structure has been examined by electron microscopy after negative staining. The orderly helical arrangement of myosin projections characteristic of the relaxed state is largely lost upon activation. The oblique striping that arises from alignment of elongated projections along the long-pitched helical tracks is greatly weakened, although a 145 A axial periodicity is sometimes partially retained. The edges of the filaments become rough, and the myosin heads move outwards as their helical arrangement becomes disordered. Crossbridges at various angles appear to link thick and thin filaments after activation. The transition from order to disorder is reversible and occurs over a narrow range of free calcium concentration near pCa 5.7. Removal of nucleotide, as well as dissociation of regulatory light chains, also disrupts the ordered helical arrangement of projections. We suggest that the relaxed arrangement of the projections is probably maintained by intermolecular interactions between myosin molecules, which depend on the regulatory light chains. Calcium binding changes the interactions between light chains and the rest of the head, activating the myosin molecule. Intermolecular contacts between molecules may thus be altered and may propagate activation cooperatively throughout the thick filament.

Full Text

The Full Text of this article is available as a PDF (1.0 MB).

Selected References

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

  1. Adelstein R. S., Conti M. A. Phosphorylation of platelet myosin increases actin-activated myosin ATPase activity. Nature. 1975 Aug 14;256(5518):597–598. doi: 10.1038/256597a0. [DOI] [PubMed] [Google Scholar]
  2. Bagshaw C. R., Kendrick-Jones J. Characterization of homologous divalent metal ion binding sites of vertebrate and molluscan myosins using electron paramagnetic resonance spectroscopy. J Mol Biol. 1979 May 25;130(3):317–336. doi: 10.1016/0022-2836(79)90544-8. [DOI] [PubMed] [Google Scholar]
  3. Barnett V. A., Thomas D. D. Saturation transfer electron paramagnetic resonance of spin-labeled muscle fibers. Dependence of myosin head rotational motion on sarcomere length. J Mol Biol. 1984 Oct 15;179(1):83–102. doi: 10.1016/0022-2836(84)90307-3. [DOI] [PubMed] [Google Scholar]
  4. Bennett A. J., Patel N., Wells C., Bagshaw C. R. 8-Anilino-1-naphthalenesulphonate, a fluorescent probe for the regulatory light chain binding site of scallop myosin. J Muscle Res Cell Motil. 1984 Apr;5(2):165–182. doi: 10.1007/BF00712154. [DOI] [PubMed] [Google Scholar]
  5. Chantler P. D., Sellers J. R., Szent-Györgyi A. G. Cooperativity in scallop myosin. Biochemistry. 1981 Jan 6;20(1):210–216. doi: 10.1021/bi00504a035. [DOI] [PubMed] [Google Scholar]
  6. Chantler P. D., Szent-Györgyi A. G. Regulatory light-chains and scallop myosin. Full dissociation, reversibility and co-operative effects. J Mol Biol. 1980 Apr 15;138(3):473–492. doi: 10.1016/s0022-2836(80)80013-1. [DOI] [PubMed] [Google Scholar]
  7. Craig R., Szent-Györgyi A. G., Beese L., Flicker P., Vibert P., Cohen C. Electron microscopy of thin filaments decorated with a Ca2+-regulated myosin. J Mol Biol. 1980 Jun 15;140(1):35–55. doi: 10.1016/0022-2836(80)90355-1. [DOI] [PubMed] [Google Scholar]
  8. Dabrowska R., Sherry J. M., Aromatorio D. K., Hartshorne D. J. Modulator protein as a component of the myosin light chain kinase from chicken gizzard. Biochemistry. 1978 Jan 24;17(2):253–258. doi: 10.1021/bi00595a010. [DOI] [PubMed] [Google Scholar]
  9. Elliott A., Offer G. Shape and flexibility of the myosin molecule. J Mol Biol. 1978 Aug 25;123(4):505–519. doi: 10.1016/0022-2836(78)90204-8. [DOI] [PubMed] [Google Scholar]
  10. Flicker P. F., Wallimann T., Vibert P. Electron microscopy of scallop myosin. Location of regulatory light chains. J Mol Biol. 1983 Sep 25;169(3):723–741. doi: 10.1016/s0022-2836(83)80167-3. [DOI] [PubMed] [Google Scholar]
  11. Greene L. E., Eisenberg E. Cooperative binding of myosin subfragment-1 to the actin-troponin-tropomyosin complex. Proc Natl Acad Sci U S A. 1980 May;77(5):2616–2620. doi: 10.1073/pnas.77.5.2616. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hardwicke P. M., Szent-Györgyi A. G. Proximity of regulatory light chains in scallop myosin. J Mol Biol. 1985 May 25;183(2):203–211. doi: 10.1016/0022-2836(85)90213-x. [DOI] [PubMed] [Google Scholar]
  13. Hardwicke P. M., Wallimann T., Szent-Györgyi A. G. Light-chain movement and regulation in scallop myosin. Nature. 1983 Feb 10;301(5900):478–482. doi: 10.1038/301478a0. [DOI] [PubMed] [Google Scholar]
  14. Heuser J. E., Cooke R. Actin-myosin interactions visualized by the quick-freeze, deep-etch replica technique. J Mol Biol. 1983 Sep 5;169(1):97–122. doi: 10.1016/s0022-2836(83)80177-6. [DOI] [PubMed] [Google Scholar]
  15. Hill T. L., Eisenberg E., Greene L. E. Alternate model for the cooperative equilibrium binding of myosin subfragment-1-nucleotide complex to actin-troponin-tropomyosin. Proc Natl Acad Sci U S A. 1983 Jan;80(1):60–64. doi: 10.1073/pnas.80.1.60. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. 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]
  17. Huxley H. E., Faruqi A. R., Bordas J., Koch M. H., Milch J. R. The use of synchrotron radiation in time-resolved X-ray diffraction studies of myosin layer-line reflections during muscle contraction. Nature. 1980 Mar 13;284(5752):140–143. doi: 10.1038/284140a0. [DOI] [PubMed] [Google Scholar]
  18. Huxley H. E., Faruqi A. R., Kress M., Bordas J., Koch M. H. Time-resolved X-ray diffraction studies of the myosin layer-line reflections during muscle contraction. J Mol Biol. 1982 Jul 15;158(4):637–684. doi: 10.1016/0022-2836(82)90253-4. [DOI] [PubMed] [Google Scholar]
  19. Huxley H. E., Simmons R. M., Faruqi A. R., Kress M., Bordas J., Koch M. H. Changes in the X-ray reflections from contracting muscle during rapid mechanical transients and their structural implications. J Mol Biol. 1983 Sep 15;169(2):469–506. doi: 10.1016/s0022-2836(83)80062-x. [DOI] [PubMed] [Google Scholar]
  20. 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]
  21. Kendrick-Jones J., Jakes R., Tooth P., Craig R., Scholey J. Role of the myosin light chains in the regulation of contractile activity. Soc Gen Physiol Ser. 1982;37:255–272. [PubMed] [Google Scholar]
  22. Kendrick-Jones J., Lehman W., Szent-Györgyi A. G. Regulation in molluscan muscles. J Mol Biol. 1970 Dec 14;54(2):313–326. doi: 10.1016/0022-2836(70)90432-8. [DOI] [PubMed] [Google Scholar]
  23. Kendrick-Jones J., Szentkiralyi E. M., Szent-Györgyi A. G. Regulatory light chains in myosins. J Mol Biol. 1976 Jul 15;104(4):747–775. doi: 10.1016/0022-2836(76)90180-7. [DOI] [PubMed] [Google Scholar]
  24. Kensler R. W., Levine R. J. An electron microscopic and optical diffraction analysis of the structure of Limulus telson muscle thick filaments. J Cell Biol. 1982 Feb;92(2):443–451. doi: 10.1083/jcb.92.2.443. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Kensler R. W., Levine R. J. Determination of the handedness of the crossbridge helix of Limulus thick filaments. J Muscle Res Cell Motil. 1982 Sep;3(3):349–361. doi: 10.1007/BF00713042. [DOI] [PubMed] [Google Scholar]
  26. Kensler R. W., Stewart M. Frog skeletal muscle thick filaments are three-stranded. J Cell Biol. 1983 Jun;96(6):1797–1802. doi: 10.1083/jcb.96.6.1797. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Knight P., Trinick J. Structure of the myosin projections on native thick filaments from vertebrate skeletal muscle. J Mol Biol. 1984 Aug 15;177(3):461–482. doi: 10.1016/0022-2836(84)90295-x. [DOI] [PubMed] [Google Scholar]
  28. Lehman W., Szent-Györgyi A. G. Regulation of muscular contraction. Distribution of actin control and myosin control in the animal kingdom. J Gen Physiol. 1975 Jul;66(1):1–30. doi: 10.1085/jgp.66.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Levine R. J., Kensler R. W., Reedy M. C., Hofmann W., King H. A. Structure and paramyosin content of tarantula thick filaments. J Cell Biol. 1983 Jul;97(1):186–195. doi: 10.1083/jcb.97.1.186. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Margossian S. S., Bhan A. K., Slayter H. S. Role of the regulatory light chains in skeletal muscle actomyosin ATPase and in minifilament formation. J Biol Chem. 1983 Nov 10;258(21):13359–13369. [PubMed] [Google Scholar]
  31. McDowall A. W., Hofmann W., Lepault J., Adrian M., Dubochet J. Cryo-electron microscopy of vitrified insect flight muscle. J Mol Biol. 1984 Sep 5;178(1):105–111. doi: 10.1016/0022-2836(84)90233-x. [DOI] [PubMed] [Google Scholar]
  32. Miller A., Tregear R. T. Structure of insect fibrillar flight muscle in the presence and absence of ATP. J Mol Biol. 1972 Sep 14;70(1):85–104. doi: 10.1016/0022-2836(72)90165-9. [DOI] [PubMed] [Google Scholar]
  33. Persechini A., Hartshorne D. J. Phosphorylation of smooth muscle myosin: evidence for cooperativity between the myosin heads. Science. 1981 Sep 18;213(4514):1383–1385. doi: 10.1126/science.6455737. [DOI] [PubMed] [Google Scholar]
  34. Poulsen F. R., Lowy J. Small-angle X-ray scattering from myosin heads in relaxed and rigor frog skeletal muscles. Nature. 1983 May 12;303(5913):146–152. doi: 10.1038/303146a0. [DOI] [PubMed] [Google Scholar]
  35. Rayment I., Winkelmann D. A. Crystallization of myosin subfragment 1. Proc Natl Acad Sci U S A. 1984 Jul;81(14):4378–4380. doi: 10.1073/pnas.81.14.4378. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Sellers J. R. Phosphorylation-dependent regulation of Limulus myosin. J Biol Chem. 1981 Sep 10;256(17):9274–9278. [PubMed] [Google Scholar]
  37. Sherry J. M., Górecka A., Aksoy M. O., Dabrowska R., Hartshorne D. J. Roles of calcium and phosphorylation in the regulation of the activity of gizzard myosin. Biochemistry. 1978 Oct 17;17(21):4411–4418. doi: 10.1021/bi00614a009. [DOI] [PubMed] [Google Scholar]
  38. Simmons R. M., Szent-Györgyi A. G. Reversible loss of calcium control of tension in scallop striated muscle associated with the removal of regulatory light chains. Nature. 1978 May 4;273(5657):62–64. doi: 10.1038/273062a0. [DOI] [PubMed] [Google Scholar]
  39. Slayter H. S., Lowey S. Substructure of the myosin molecule as visualized by electron microscopy. Proc Natl Acad Sci U S A. 1967 Oct;58(4):1611–1618. doi: 10.1073/pnas.58.4.1611. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Stewart M., Kensler R. W., Levine R. J. Structure of Limulus telson muscle thick filaments. J Mol Biol. 1981 Dec 15;153(3):781–790. doi: 10.1016/0022-2836(81)90418-6. [DOI] [PubMed] [Google Scholar]
  41. Szentkiralyi E. M. Tryptic digestion of scallop S1: evidence for a complex between the two light-chains and a heavy-chain peptide. J Muscle Res Cell Motil. 1984 Apr;5(2):147–164. doi: 10.1007/BF00712153. [DOI] [PubMed] [Google Scholar]
  42. Taylor K. A., Glaeser R. M. Electron diffraction of frozen, hydrated protein crystals. Science. 1974 Dec 13;186(4168):1036–1037. doi: 10.1126/science.186.4168.1036. [DOI] [PubMed] [Google Scholar]
  43. 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]
  44. Vibert P., Cohen C., Hardwicke P. M., Szent-Györgyi A. G. Electron microscopy of cross-linked scallop myosin. J Mol Biol. 1985 May 25;183(2):283–286. doi: 10.1016/0022-2836(85)90221-9. [DOI] [PubMed] [Google Scholar]
  45. Vibert P., Craig R. Electron microscopy and image analysis of myosin filaments from scallop striated muscle. J Mol Biol. 1983 Apr 5;165(2):303–320. doi: 10.1016/s0022-2836(83)80259-9. [DOI] [PubMed] [Google Scholar]
  46. Wallimann T., Hardwicke P. M., Szent-Györgyi A. G. Regulatory and essential light-chain interactions in scallop myosin. II. Photochemical cross-linking of regulatory and essential light-chains by heterobifunctional reagents. J Mol Biol. 1982 Mar 25;156(1):153–173. doi: 10.1016/0022-2836(82)90464-8. [DOI] [PubMed] [Google Scholar]
  47. Wells C., Bagshaw C. R. Calcium regulation of molluscan myosin ATPase in the absence of actin. Nature. 1985 Feb 21;313(6004):696–697. doi: 10.1038/313696a0. [DOI] [PubMed] [Google Scholar]
  48. Winkelmann D. A., Almeda S., Vibert P., Cohen C. A new myosin fragment: visualization of the regulatory domain. Nature. 1984 Feb 23;307(5953):758–760. doi: 10.1038/307758a0. [DOI] [PubMed] [Google Scholar]
  49. Winkelmann D. A., Mekeel H., Rayment I. Packing analysis of crystalline myosin subfragment-1. Implications for the size and shape of the myosin head. J Mol Biol. 1985 Feb 20;181(4):487–501. doi: 10.1016/0022-2836(85)90422-x. [DOI] [PubMed] [Google Scholar]
  50. Wray J. S. Structure of the backbone in myosin filaments of muscle. Nature. 1979 Jan 4;277(5691):37–40. doi: 10.1038/277037a0. [DOI] [PubMed] [Google Scholar]
  51. Wray J. S., Vibert P. J., Cohen C. Diversity of cross-bridge configurations in invertebrate muscles. Nature. 1975 Oct 16;257(5527):561–564. doi: 10.1038/257561a0. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

RESOURCES