Some physico-chemical parameters that influence proteinase K resistance and the infectivity of PrP Sc after high pressure treatment
Braz. j. med. biol. res
;
38(8): 1223-1231, Aug. 2005. ilus, tab
Article
in English
| LILACS
| ID: lil-405524
ABSTRACT
Crude brain homogenates of terminally diseased hamsters infected with the 263 K strain of scrapie (PrP Sc) were heated and/or pressurized at 800 MPa at 60°C for different times (a few seconds or 5, 30, 120 min) in phosphate-buffered saline (PBS) of different pH and concentration. Prion proteins were analyzed on immunoblots for their proteinase K (PK) resistance, and in hamster bioassays for their infectivity. Samples pressurized under initially neutral conditions and containing native PrP Sc were negative on immunoblots after PK treatment, and a 6-7 log reduction of infectious units per gram was found when the samples were pressurized in PBS of pH 7.4 for 2 h. A pressure-induced change in the protein conformation of native PrP Sc may lead to less PK resistant and less infectious prions. However, opposite results were obtained after pressurizing native infectious prions at slightly acidic pH and in PBS of higher concentration. In this case an extensive fraction of native PrP Sc remained PK resistant after pressure treatment, indicating a protective effect possibly due to induced aggregation of prion proteins in such buffers.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
PrPSc Proteins
/
Endopeptidase K
/
Hydrostatic Pressure
Limits:
Animals
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2005
Type:
Article
/
Congress and conference
/
Project document
Affiliation country:
Germany
Institution/Affiliation country:
Institute of Chemistry and Biology/DE
/
Institute of Immunology/DE
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