Pre-incubating scrapie-negative brain homogenate with peptide before initiating conversion with scrapie-positive brain homogenate, surprisingly resulted in increased formation of proteinase-K resistant PrP (PrPres) after sonication for five [NTG, TD2, AM, CO and CT] of the six peptides tested (results summerized in Table 2) generally in a dose dependant manner. Here, PRNP is linked to scrapie.