PRNP and prion disease: Using the latter approach, we have shown that, in the presence of total RNA isolated from mouse liver plus synthetic phospholipid POPG (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1′-rac-glycerol), recombinant murine prion protein (rPrP) purified from E. coli can be converted into the highly infectious and PK-resistant conformer rPrP-resRNA[7,19], which causes prion disease in wild-type animals and has the same pathogenic properties as naturally occurring prions[8].