Prion Protein Misfolding, Strains, and Neurotoxicity: An Update from Studies on Mammalian Prions

Table 1

Cofactors enhancing PrP^C conversion in vitro.

Cofactor	Experimental setting		Results	Refs.
Pentosan polysulfate; (PPS)	Cell-free conversion assay	Hamster and mouse [^35S] GPI(-) PrP^C seeded with brain derived PrP^res from infected hamsters (263 K) and mice (87 V)	(i) PPS increases the rate of formation and the yield of [^35S] PrP^res; (ii) PPS facilitates conversion of both Mo and SHa [^35S] GPI(-) PrP^Cat different temperatures	[44]
Heparin	Cell-PMCA	Cell lysates plus exogenously expressed HuPrP seeded with sCJD, vCJD, and hamster-adapted scrapie 263 K	(i) Both low and high molecular weight heparin enhance PMCA efficiency; (ii) Seed-dependent effect of heparin on amplification efficiency	[45]
Sulfated dextran compounds	PMCA	PrP^Sc derived from BSE-infected cattle brain diluted in PrP^C substrate	(i) Enhanced BSE PrP^Sc amplification; (ii) Amplified PrP^Sc induce lesions typical of prion disease in TgBoPrP	[135]
Synthetic poly (A) RNA	PMCA	Normal and diluted scrapie brain homogenate	(i) Stochastic de novo formation of PrP^Sc molecules from unseeded purified substrates; (ii) Both amplified Sc237 or 139H PrP^Sc and de novo PrP^Sc molecules cause scrapie in inoculated Syrian hamsters	[136]
Phosphatidylethanolamine (PE)	PMCA	recPrP substrate with a recPrP^Sc seed	(i) Generation of infectious prions; (ii) PE supports prion propagation using PrP molecules from multiple animal species	[55]
RNA from normal mouse liver plus POPG	PMCA	Normal mouse brain homogenate seeded with recPrP	(i) In vitro generated recPrP^res; (ii) recPrP^res propagates its PK-resistant conformation to endogenous PrP^C; (iii) recPrP^res causes bona fide prion disease in wild-type mice	[50]