Summary
Low-angle X-ray diffraction patterns have been taken of relaxed frog sartorius muscles stretched to destroy the lattice sampling in the pattern and the observed layer line pattern has been interpreted with model-building studies. The modelling calculations indicate that each crossbridge cannot be represented by a single cylindrical shape, but that the two S-1 heads of the crossbridge are tilted in opposite directions along the filament while twisted the same way round it so that the crossbridge lies wrapped round the filament backbone. The radial position derived for the crossbridge depends on how many strands the filament is assumed to have. If the filament is 2, 3 or 4 stranded then the centre of mass of the crossbridge lies at about 9.5, 12.5, or 15.5 nm respectively from the filament axis.
Similar content being viewed by others
References
FRANKLIN, R. E. & KLUG, A. (1955) The splitting of layer-lines in X-ray fibre diagrams of helical structures. Applications to tobacco mosaic virus.Acta. cryst. 8, 777–80.
HASELGROVE, J. C. (1970)X-ray diffraction studies on muscles. Ph.D. dissertation. University of Cambridge, England.
HASELGROVE, J. C. (1972) X-ray evidence for a conformational change in the actin containing filaments of vertebrate striated muscles.Cold Spring Harbor Symp. quant. Biol. 37, 341–52.
HASELGROVE, J. C. (1975) X-ray evidence for conformational changes in the myosin filaments of vertebrate striated muscle.J. molec. Biol. 92, 113–43.
HASELGROVE, J. C. & HUXLEY, H. E. (1973) X-ray evidence for radial cross-bridge movement and for the sliding filament model in actively contracting muscle.J. molec. Bio. 77, 549–68.
HUXLEY, H. E. (1952)X-ray diffraction studies of muscle. Ph.D. thesis, University of Cambridge.
HUXLEY, H. E. (1963) Electron microscope studies of the structure of natural and synthetic protein filaments from striated muscle.J. molec. Biol. 7, 281–308.
HUXLEY, H. E. (1968) Structural difference between resting and rigor muscle; Evidence from intensity changes in the low-angle equatorial X-ray diagram.J. molec. Biol. 37, 507–20.
HUXLEY, H. E. (1969) The mechanism of muscle contraction.Science 164, 1356–66.
HUXLEY, H. E. & BROWN, W. (1967) The low angle X-ray diagram of vertebrate striated muscle and its behaviour during contraction and rigor.J. molec. Biol. 30, 383–434.
MILLER, A. & TREGEAR, R. T. (1972) Structure of insect fibrillar flight muscle in the presence and absence of ATP.J. molec. Biol. 70, 85–104.
MOORE, P. B., HUXLEY, H. E. & De ROSIER, D. J. (1970) Three dimensional reconstruction of F actin thin filaments and decorated thin filaments.J. molec. Biol. 50, 279–95.
MORIMOTO, K. & HARRINGTON, W. F. (1974) Substructure of thick filament of vertebrate striated muscle.J. molec. Biol. 83, 83–97.
OFFER, G. & ELLIOTT, A. (1978) Can a myosin molecule bind to two actin filaments?Nature 271, 325–9.
SQUIRE, J. M. (1972) General model of myosin filament structure.J. molec. Biol. 72, 125–38.
SQUIRE, J. M. (1973) General model of myosin filament structure III. Molecular packing arrangements in myosin filaments.J. molec. Biol. 77, 291–323.
SQUIRE, J. M. (1975) Muscle filament structure and muscle contraction.Ann. Rev. Biophys. Bioeng. 4, 137–63.
SUTOH, K. & HARRINGTON, W. (1977) Cross linking of myosin filaments under activating and rigor conditions.Biochemistry 16, 2441–9.
TREGEAR, R. T. & SQUIRE, J. M. (1973) Myosin content and filament structure in smooth and striated muscle.J. molec. Biol. 77, 279–90.
VIBERT, P. J., HASELGROVE, J. C., LOWY, J. & POULSEN, F. R. (1972) Structural changes in actin-containing filaments of muscle.J. molec. Biol. 71, 757–67.
WAKABAYASHI, T., HUXLEY, H. E., AMOS, L. A. & KLUG, A. (1975) Three-dimensional image reconstruction of actin-tropomyosin complex and actin-tropomyosin-troponin-T — troponin-I complex.J. molec. Biol. 93, 477–97.
WRAY, J. S., VIBERT, P. J. & COHEN, C. (1975) Diversity of cross-bridge configurations in invertebrate muscles.Nature 257, 561–4.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Haselgrove, J.C. A model of myosin crossbridge structure consistent with the low-angle X-ray diffraction pattern of vertebrate muscle. J Muscle Res Cell Motil 1, 177–191 (1980). https://doi.org/10.1007/BF00711798
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00711798