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
Artigo
em Inglês
| 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.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Proteínas PrPSc
/
Endopeptidase K
/
Pressão Hidrostática
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
2005
Tipo de documento:
Artigo
/
Congresso e conferência
/
Documento de projeto
País de afiliação:
Alemanha
Instituição/País de afiliação:
Institute of Chemistry and Biology/DE
/
Institute of Immunology/DE
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