Open AccessIn Situ Photodegradation of Incorporated Polyanion Does Not Alter Prion Infectivity
Author(s) -
Justin R. Piro,
Brent T. Harris,
Surachai Supattapone
Publication year - 2011
Publication title -
plos pathogens
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.719
H-Index - 206
eISSN - 1553-7374
pISSN - 1553-7366
DOI - 10.1371/journal.ppat.1002001
Subject(s) - scrapie , in vitro , infectivity , chemistry , hamster , nuclease , biophysics , in vivo , biochemistry , microbiology and biotechnology , dna , prion protein , biology , virology , virus , medicine , disease , pathology
Single-stranded polyanions ≥40 bases in length facilitate the formation of hamster scrapie prions in vitro , and polyanions co-localize with PrP Sc aggregates in vivo [1] , [2] . To test the hypothesis that intact polyanionic molecules might serve as a structural backbone essential for maintaining the infectious conformation(s) of PrP Sc , we produced synthetic prions using a photocleavable, 100-base oligonucleotide (PC-oligo). In serial Protein Misfolding Cyclic Amplification (sPMCA) reactions using purified PrP C substrate, PC-oligo was incorporated into physical complexes with PrP Sc molecules that were resistant to benzonase digestion. Exposure of these nuclease-resistant prion complexes to long wave ultraviolet light (315 nm) induced degradation of PC-oligo into 5 base fragments. Light-induced photolysis of incorporated PC-oligo did not alter the infectivity of in vitro -generated prions, as determined by bioassay in hamsters and brain homogenate sPMCA assays. Neuropathological analysis also revealed no significant differences in the neurotropism of prions containing intact versus degraded PC-oligo. These results show that polyanions >5 bases in length are not required for maintaining the infectious properties of in vitro -generated scrapie prions, and indicate that such properties are maintained either by short polyanion remnants, other co-purified cofactors, or by PrP Sc molecules alone.