PRNP and prion disease: Furthermore, the substitution of copper-binding histidine (H) residue to glycine (G) residue at position 95 in mouse PrP was reported to accelerate prion disease in mice after infection with RML prions [28], suggesting that copper-binding at H95 might also structurally stabilize PrPC and thereby play an inhibitory role in the conversion of PrPC into PrPSc.