Pitfalls in prion research

Prion research seems to get increasingly enigmatic since the protein only hypothesis has been established as almost the only working hypothesis. This may indicate that the hypothesis could be wrong, and should prompt the search for potential faults in past experiments. In fact some problematic experiments can be pinpointed, for example determination of the N-terminal cleavage site of the prion protein PrP, of the structure of PrP as determined by NMR, some conclusions concerning the function of PrP from gene knockout experiments including potential evidence against the protein only hypothesis, and some aspects of the prion purification procedure.