Decrease of Protease-Resistant PrP Level in ScN2a Cells by Polyornithine and Polyhistidine.

Based on previous studies reporting the anti-prion activity of poly--lysine and poly--arginine, we investigated cationic poly--ornithine (PLO), poly--histidine (PLH), anionic poly--glutamic acid (PLE) and uncharged poly--threonine (PLT) in cultured cells chronically infected by prions to determine their anti-prion efficacy. While PLE and PLT did not alter the level of PrP, PLO and PLH exhibited potent PrP inhibition in ScN2a cells. These results suggest that the anti-prion activity of poly-basic amino acids is correlated with the cationicity of their functional groups. Comparison of anti-prion activity of PLO and PLH proposes that the anti-prion activity of poly-basic amino acids is associated with their acidic cellular compartments.