Using bacterial inclusion bodies to screen for amyloid aggregation inhibitors
- Equal contributors
1 Departament de Bioquímica i Biologia Molecular, Facultat de Biociències, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Spain
2 Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Spain
3 Present address: Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona, Avda. Joan XXIII, 08028, Barcelona, Spain
4 Present address: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, United Kingdom
Microbial Cell Factories 2012, 11:55 doi:10.1186/1475-2859-11-55Published: 3 May 2012
The amyloid-β peptide (Aβ42) is the main component of the inter-neuronal amyloid plaques characteristic of Alzheimer's disease (AD). The mechanism by which Aβ42 and other amyloid peptides assemble into insoluble neurotoxic deposits is still not completely understood and multiple factors have been reported to trigger their formation. In particular, the presence of endogenous metal ions has been linked to the pathogenesis of AD and other neurodegenerative disorders.
Here we describe a rapid and high-throughput screening method to identify molecules able to modulate amyloid aggregation. The approach exploits the inclusion bodies (IBs) formed by Aβ42 when expressed in bacteria. We have shown previously that these aggregates retain amyloid structural and functional properties. In the present work, we demonstrate that their in vitro refolding is selectively sensitive to the presence of aggregation-promoting metal ions, allowing the detection of inhibitors of metal-promoted amyloid aggregation with potential therapeutic interest.
Because IBs can be produced at high levels and easily purified, the method overcomes one of the main limitations in screens to detect amyloid modulators: the use of expensive and usually highly insoluble synthetic peptides.