1887

Abstract

SUMMARY

Fresh mouse scrapie brain and frozen mouse scrapie spleen were homogenized, sized by ultrafiltration to a fraction containing particles of 30 nm to 200 nm and separated by zonal centrifugation in sucrose gradients. In both the brain and spleen, the maximum titre of scrapie infectivity banded between densities of 1.125 to 1.200 g/ml; but in spleen a second fraction of scrapie infectivity was observed between 1.200 to 1.250 g/ml. A unique 30 to 60 nm particle was found in mouse spleen gradient fractions with high scrapie infectivity titres. This particle was not observed in similar fractions isolated from normal mouse spleen or brain and was rarely found in subcellular fractions of low titre from scrapie-infected tissues. The particle was first observed by negative staining and then confirmed in thin sections after staining with ruthenium red and potassium permanganate. The previously observed ‘smearing’ of scrapie infectivity over broad ranges in sucrose density gradients may now be explained since these particles were often found as aggregates or chains of particles. The significance of these particles in scrapie infectivity remains uncertain at this time, but absence of these structures in normal tissue fractions may provide a promising new morphological approach to the purification of the infective scrapie agent.

Loading

Article metrics loading...

/content/journal/jgv/10.1099/0022-1317-43-2-417
1979-05-01
2024-12-06
Loading full text...

Full text loading...

/deliver/fulltext/jgv/43/2/JV0430020417.html?itemId=/content/journal/jgv/10.1099/0022-1317-43-2-417&mimeType=html&fmt=ahah

References

  1. Adams D. H., Caspary E. A., Field E. J. 1969; The incorporation of [3H] thymidine, [14C]orotic acid, [14C]uridine-diphospho-glucose and [14C]glucosamine into a post-ribosomal fraction of normal and scrapie-affected mouse brain and spleen. Journal of General Virology 4:89–100
    [Google Scholar]
  2. Bennett H. S., Luft J. H. 1959; S-collidine as a basis for buffering fixatives. Journal of Biophysical and Biochemical Cytology 6:113–114
    [Google Scholar]
  3. Clark M. C., Haig D. C. 1970; Multiplication of scrapie agent in cell culture. Research in Veterinary Science 11:500–501
    [Google Scholar]
  4. Clark M. C., Millson G. C. 1976; The membrane location of scrapie infectivity. Journal of General Virology 31:441–445
    [Google Scholar]
  5. Dermer G. B. 1973; Specificity of phosphotungstic acid used as a section stain to visualize surface coats of cells. Journal of Ultrastructural Research 45:183–191
    [Google Scholar]
  6. Doggenweiler C. F., Frenk S. 1965; Staining properties of lanthanum on cell membranes. Proceedings of the National Academy of Sciences of the United States of America 53:425–430
    [Google Scholar]
  7. Gibbs C. J. 1967; Search for infectious etiology in chronic subacute degenerative diseases of the central nervous system. Current Topics in Microbiology and Immunology 40:44–58
    [Google Scholar]
  8. Hunter G. D., Milson G. C. 1973; Glycoprotein biosynthesis in normal and scrapie-affected mouse brain. Journal of Comparative Pathology 83:217–224
    [Google Scholar]
  9. Huxley H. E., Zubay G. 1961; Preferential staining of nucleic acid-containing structures for electron microscopy. Journal of Biophysical and Biochemical Cytology 11:273–296
    [Google Scholar]
  10. Luft J. H. 1971a; Ruthenium red and violet. I. Chemistry, purification, methods of use for electron microscopy and mechanism of action. Anatomical Record 171:347–368
    [Google Scholar]
  11. Luft J. H. 1971b; Ruthenium red and violet. II. Fine structural localization in animal tissues. Anatomical Record 171:369–415
    [Google Scholar]
  12. Mollenhauer H. H. 1959; Permanganate fixation of plant cells. Journal of Biophysical and Biochemical Cytology 6:431–436
    [Google Scholar]
  13. Narang H. K. 1974; Ruthenium red and lanthanum nitrate - a possible tracer and negative stain for scrapie ‘particles’?. Acta Neuropathologica 29:37–43
    [Google Scholar]
  14. Oliver R. M. 1973 In Methods in Enzymology volume 27 pp 616–672 Edited by Hirs C. W., Timasheff S. N. New York: Academic Press, Inc;
    [Google Scholar]
  15. Prusiner S. B., Hadlow W. J., Eklund C. W., Cochran S. P., Garfin D. E., Hooper C. E., Baringer J. R. 1977; Scrapie sediments as a discrete particle. Federation Proceedings 36: 2463 (abstract)
    [Google Scholar]
  16. Prusiner S. B., Hadlow W. J., Eklund C. W., Race R. E. 1978; Sedimentation properties of the scrapie agent. Proceedings of the National Academy of Science of the United States of America 74:4656–4660
    [Google Scholar]
  17. Siakotos A. N., Gajdusdek D. C., Gibbs C. J., Traub R. D., Bucana C. 1976; Studies on the purification of the scrapie agent from mouse brain by pressure disruption, filtration, and zonal centrifugation in a sucrose-sodium chloride gradient. Virology 80:230–237
    [Google Scholar]
  18. Spurr A. R. 1969; A low-viscosity epoxy resin embedding medium for electron microscopy. Journal of Ultrastructural Research 26:31–43
    [Google Scholar]
  19. Suckling A. J., Hunter C. D. 1974; Glycosyl transferase activity in normal and scrapie-affected mouse brain. Journal of Neurochemistry 221005–1012
    [Google Scholar]
/content/journal/jgv/10.1099/0022-1317-43-2-417
Loading
/content/journal/jgv/10.1099/0022-1317-43-2-417
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error