Systematic identification of antiprion drugs by high-throughput screening based on scanning for intensely fluorescent targets.
Conformational changes and aggregation of specific proteins are hallmarks of a number of diseases, like Alzheimer's disease, Parkinson's disease, and prion diseases. In the case of prion diseases, the prion protein (PrP), a neuronal glycoprotein, undergoes a conformational change from the normal, mainly alpha-helical conformation to a disease-associated, mainly beta-sheeted scrapie isoform (PrP(Sc)), which forms amyloid aggregates. This conversion, which is crucial for disease progression, depends on direct PrP(C)/PrP(Sc) interaction. We developed a high-throughput assay based on scanning for intensely fluorescent targets (SIFT) for the identification of drugs which interfere with this interaction at the molecular level. Screening of a library of 10,000 drug-like compounds yielded 256 primary hits, 80 of which were confirmed by dose response curves with half-maximal inhibitory effects ranging from 0.3 to 60 microM. Among these, six compounds displayed an inhibitory effect on PrP(Sc) propagation in scrapie-infected N2a cells. Four of these candidate drugs share an N'-benzylidene-benzohydrazide core structure. Thus, the combination of high-throughput in vitro assay with the established cell culture system provides a rapid and efficient method to identify new antiprion drugs, which corroborates that interaction of PrP(C) and PrP(Sc) is a crucial molecular step in the propagation of prions. Moreover, SIFT-based screening may facilitate the search for drugs against other diseases linked to protein aggregation.
Bertsch
Uwe
U
Zentrum für Neuropathologie und Prionforschung, Ludwig Maximilians Universität, Feodor Lynen Str. 23, D-81377 München, Germany.
Winklhofer
Konstanze F
KF
Hirschberger
Thomas
T
Bieschke
Jan
J
Weber
Petra
P
Hartl
F Ulrich
FU
Tavan
Paul
P
Tatzelt
Jörg
J
Kretzschmar
Hans A
HA
Giese
Armin
A
D000818:Animals; D001597:Benzylidene Compounds / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D005453:Fluorescence; D006801:Humans; D051379:Mice; D004364:Pharmaceutical Preparations / Q000737:chemistry; D018621:PrPC Proteins / Q000737:chemistry; D018620:PrPSc Proteins / Q000737:chemistry; D017096:Prion Diseases / Q000188:drug therapy; D011328:Prions / Q000037:antagonists & inhibitors* / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D025941:Protein Interaction Mapping / Q000379:methods*
D001597:Benzylidene Compounds; D004364:Pharmaceutical Preparations; D018621:PrPC Proteins; D018620:PrPSc Proteins; D011328:Prions