Concentration and removal of prion proteins from biological solutions.
The pathogenesis of prion diseases is characterized by the accumulation of amyloid-like rods or scrapie-associated fibrils. The major protein component of scrapie-associated fibrils is an abnormally folded isoform of the normal cellular prion protein (PrP(C)) that is resistant to digestion by proteinase K and is referred to as PrP(Sc). Purified human recombinant (hr PrP) was used to characterize the binding of a set of RNAs with affinity to PrP proteins. We report here that hr PrP has two RNA-binding activities at physiological pH. One activity is capable of binding all of the screened RNAs with high affinity, whereas the other activity can bind only to a subset of the RNAs with high affinity in the presence of non-specific competitor RNAs. A novel RNA belonging to the latter class, RQ11+12, bound to hr PrP with high affinity in the presence of vast molar excesses of competing RNAs. Beads impregnated with the RQ11+12 RNA were used to construct a filtration column. The column efficiently bound hr PrP and native PrP(C) from serum and urine. Importantly, the filtration device was also capable of binding proteinase K-treated PrP(Sc) from serum and urine. The level of sensitivity of detection of PrP by standard Western blotting was increased at least 1000-fold by first concentrating PrP from solution with the filtration column.
Zeiler
Brian
B
Q-RNA, Inc., 3960 Broadway, New York, NY 10032-1543, U.S.A. bzeiler@q-rna.com
Adler
Victor
V
Kryukov
Valentin
V
Grossman
Abraham
A
D002846:Chromatography, Affinity / Q000379:methods*; D008567:Membranes, Artificial; D018621:PrPC Proteins / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification* / Q000652:urine; D011485:Protein Binding; D012313:RNA / Q000138:chemical synthesis / Q000737:chemistry*; D014462:Ultrafiltration / Q000379:methods*
D008567:Membranes, Artificial; D018621:PrPC Proteins; D012313:RNA