In:
Journal of General Virology, Microbiology Society, Vol. 87, No. 12 ( 2006-12-01), p. 3753-3761
Abstract:
This study describes the conversion of murine PrP C by PrP Sc from three different mouse scrapie strains (ME7, 87V and 22A) and from a mouse-passaged bovine spongiform encephalopathy (BSE) strain (BSE/Bl6). This was demonstrated by a modified, non-radioactive, cell-free conversion assay using bacterial prion protein, which was converted into a proteinase K (PK)-resistant fragment designated PrP res . Using this assay, newly formed PrP res could be detected by an antibody that discriminated de novo PrP res and the original PrP Sc seed. The results suggested that PrP res formation occurs in three phases: the first 48 h when PrP res formation is delayed, followed by a period of substantially accelerated PrP res formation and a plateau phase when a maximum concentration of PrP res is reached after 72 h. The conversion of prokaryotically expressed PrP C by ME7 and BSE prions led to unglycosylated, PK-digested, abnormal PrP res fragments, which differed in molecular mass by 1 kDa. Therefore, prion strain phenotypes were retained in the cell-free conversion, even when recombinant PrP C was used as the substrate. Moreover, co-incubation of ME7 and BSE prions resulted in equal amounts of both ME7- and BSE-derived PrP res fragments (as distinguished by their different molecular sizes) and also in a significantly increased total amount of de novo -generated PrP res . This was found to be more than twice the amount of either strain when incubated separately. This result indicates a synergistic effect of both strains during cell-free conversion. It is not yet known whether such a cooperative action between BSE and scrapie prions also occurs in vivo .
Type of Medium:
Online Resource
ISSN:
0022-1317
,
1465-2099
DOI:
10.1099/vir.0.81590-0
Language:
English
Publisher:
Microbiology Society
Publication Date:
2006
detail.hit.zdb_id:
2007065-2
SSG:
12
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