Decrease of protease-resistant PrP Sc level in ScN2a cells by polyornithine and polyhistidine.

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