Title:Small Molecules with Anti-Prion Activity
Volume: 27
Issue: 33
Author(s): Carlo Mustazza*, Marco Sbriccoli, Paola Minosi and Carla Raggi
Affiliation:
- National Centre for Control and Evaluation of Medicines, Italian National Institute of Health, Viale Regina Elena 299, 00161 Rome,Italy
Keywords:
Prions, transmissible spongiform encephalopathies, scrapie, amyloid, histological dyes, Structure-
Activity Relationship (SAR).
Abstract: Prion pathologies are fatal neurodegenerative diseases caused by the misfolding of the
physiological Prion Protein (PrPC) into a β-structure-rich isoform called PrPSc. To date, there is no
available cure for prion diseases and just a few clinical trials have been carried out. The initial approach
in the search of anti-prion agents had PrPSc as a target, but the existence of different prion
strains arising from alternative conformations of PrPSc, limited the efficacy of the ligands to a straindependent
ability. That has shifted research to PrPC ligands, which either act as chaperones, by stabilizing
the native conformation, or inhibit its interaction with PrPSc. The role of transition-metal
mediated oxidation processes in prion misfolding has also been investigated. Another promising
approach is the indirect action via other cellular targets, like membrane domains or the Protein-
Folding Activity of Ribosomes (PFAR). Also, new prion-specific high throughput screening techniques
have been developed. However, so far no substance has been found to be able to extend satisfactorily
survival time in animal models of prion diseases. This review describes the main features
of the Structure-Activity Relationship (SAR) of the various chemical classes of anti-prion agents.