ABSTRACT
Starting from substituted 9-chloroacridines, a series of quinacrine and spacered dimeric acridine compounds was prepared. Their ability to interrupt the protein association of prion- and Alzheimer-specific proteins and Ab peptides was explored using a fast screening system based on FACS analysis. The bis-acridines displayed a higher activity than the corresponding monomers. Among these derivatives, best results were obtained with the 2,4-dimethoxy-6-nitro compound 7h for Abeta-peptides and the 2-methoxy-6-nitro compound 7f for PrP.
Subject(s)
Acridines/chemical synthesis , Acridines/therapeutic use , Alzheimer Disease/drug therapy , Prion Diseases/drug therapy , Acridines/pharmacology , Amyloid beta-Peptides/drug effects , Dimerization , Drug Evaluation, Preclinical/methods , Humans , In Vitro Techniques , Molecular Structure , Prions/drug effectsABSTRACT
The synthesis of dimeric compounds derived from quinazolin-2-one and 1,4-benzodiazepin-2-one possessing a piperazine or homopiperazine spacer was investigated. In addition, a piperazine spacered bis-isoalloxazine and a bis-riboflavin compound were prepared and their ability to interrupt the association of prion proteins and Alzheimer-specific Abeta peptides was investigated using a fast screening system based on flow cytometry. The bis-isoalloxazine 14 was identified as a new lead structure.
Subject(s)
Benzodiazepinones/chemical synthesis , Dimerization , Flavins/chemical synthesis , Protein Structure, Secondary/drug effects , Quinazolinones/chemical synthesis , Amyloid beta-Peptides/chemistry , Benzodiazepinones/pharmacology , Drug Evaluation, Preclinical/methods , Flavins/pharmacology , In Vitro Techniques , Molecular Structure , Prions/chemistry , Protein Array Analysis/methods , Quinazolinones/pharmacologyABSTRACT
BACKGROUND: The definite diagnosis of prion diseases such as Creutzfeldt-Jakob disease (CJD) in humans or bovine spongiform encephalopathy (BSE) in cattle currently relies on the post mortem detection of the pathological form of the prion protein (PrPSc) in brain tissue. Infectivity studies indicate that PrPSc may also be present in body fluids, even at presymptomatic stages of the disease, albeit at concentrations well below the detection limits of currently available analytical methods. RESULTS: We developed a highly sensitive method for detecting prion protein aggregates that takes advantage of kinetic differences between seeded and unseeded polymerization of prion protein monomers. Detection of the aggregates was carried out by flow cytometry. In the presence of prion seeds, the association of labelled recombinant PrP monomers in plasma and serum proceeds much more efficiently than in the absence of seeds. In a diagnostic model system, synthetic PrP aggregates were detected down to a concentration of approximately 10(-8) nM [0.24 fg/ml]. A specific signal was detected in six out of six available serum samples from BSE-positive cattle. CONCLUSION: We have developed a method based on seed-dependent PrP fibril formation that shows promising results in differentiating a small number of BSE-positive serum samples from healthy controls. This method may provide the basis for an ante mortem diagnostic test for prion diseases.
