Showing papers by "Ryuichiro Atarashi published in 2007"
TL;DR: A much faster seeded polymerization method (rPrP-PMCA) is described which detects ≥50 ag of hamster PrPSc (≈0.003 lethal dose) within 2–3 d and should facilitate the development of rapid, ultrasensitive prion assays and diagnostic tests, in addition to aiding fundamental studies of structure and mechanism of PrP Sc formation.
Abstract: The scrapie prion protein isoform, PrPSc, is a prion-associated marker that seeds the conformational conversion and polymerization of normal protease-sensitive prion protein (PrP-sen). This seeding activity allows ultrasensitive detection of PrPSc using cyclical sonicated amplification (PMCA) reactions and brain homogenate as a source of PrP-sen. Here we describe a much faster seeded polymerization method (rPrP-PMCA) which detects ≥50 ag of hamster PrPSc (≈0.003 lethal dose) within 2–3 d. This technique uses recombinant hamster PrP-sen, which, unlike brain-derived PrP-sen, can be easily concentrated, mutated and synthetically tagged. We generated protease-resistant recombinant PrP fibrils that differed from spontaneously initiated fibrils in their proteolytic susceptibility and by their infrared spectra. This assay could discriminate between scrapie-infected and uninfected hamsters using 2-μl aliquots of cerebral spinal fluid. This method should facilitate the development of rapid, ultrasensitive prion assays and diagnostic tests, in addition to aiding fundamental studies of structure and mechanism of PrPSc formation.
322 citations