[Prions and their biology].

Prion diseases or transmissible spongiform encephalopathies are fatal neurodegenerative disorders featured by an aberrant metabolism of a cellular membrane glycoprotein, the prion protein (PrP-C). PrP-C is being related to Cu (II) homeostasis and postulated as candidate for cell signaling and cell adhesion functions. Under pathological conditions PrP-C converts into a conformational isomer (PrP*, PrP-res, PrP-Sc, PrP-Creutzfeldt-Jakob disease, etc.). In addition to divergent biochemical characteristics, the latter form displays the property of recognizing the normal protein and transforming it into its homologue. Conversion process is ill tangled and participation of yet unidentified partners has been postulated.