A microtiter plate assay for polyglutamine aggregate extension.

Area of Science:

• Biochemistry
• Neuroscience
• Molecular Biology

Background:

• Polyglutamine (polyGln) aggregates are key neuropathological markers in expanded CAG repeat disorders.
• These aggregates are implicated in the development and progression of these neurodegenerative diseases.

Purpose of the Study:

• To establish a sensitive, fast, reproducible, and specific assay for monitoring polyglutamine aggregate formation.
• To enable detailed studies on aggregation kinetics and the detection of "extension-competent" aggregates.

Main Methods:

• Immobilization of chemically synthesized polyGln aggregates onto microplate wells.
• Incubation with soluble biotinylated polyGln peptides and detection of deposited europium via time-resolved fluorescence.
• Quantification of polyGln peptide incorporation rates into existing aggregates.

Main Results:

• The assay demonstrates high sensitivity, speed, reproducibility, and specificity in monitoring polyGln aggregation.
• It allows for the detection and quantitation of low levels of aggregation-competent polyGln species.
• The method provides a quantitative measure of polyGln peptide incorporation rates.

Conclusions:

• The developed assay is a valuable tool for basic research into polyGln aggregate assembly mechanisms and length dependence.
• It serves as a crucial platform for screening and characterizing anti-aggregation inhibitors.
• The assay facilitates the detection and quantitation of aggregation-competent polyGln in biological samples, aiding disease mechanism studies.