Surface adsorption considerations when working with amyloid fibrils in multiwell plates and Eppendorf tubes

Area of Science:

• Biochemistry
• Molecular Biology
• Neuroscience

Background:

• Amyloid diseases are characterized by the accumulation of cross-β-sheet amyloid fibrils.
• Previous research suggested amyloid disaggregase activities in mammalian and C. elegans extracts.
• A re-evaluation of prior findings revealed a potential misinterpretation of experimental data.

Purpose of the Study:

• To investigate the cause of apparent amyloid-beta (Aβ) fibril disaggregation observed in previous studies.
• To determine the role of plastic surface adsorption in the loss of Aβ fibrils in the presence of biological extracts.
• To correct previously published findings regarding Aβ disaggregase activity.

Main Methods:

• Quantification of Aβ fibril adsorption to plastic and quartz surfaces.
• Analysis of thioflavin T fluorescence in the presence of biological extracts under denaturing conditions.
• Comparison of experimental results with previously published data.

Main Results:

• Aβ fibrils significantly adsorb to plastic surfaces (multiwell plates, Eppendorf tubes).
• Adsorption is enhanced by biological mixtures subjected to denaturing air-water interfaces.
• The observed loss of thioflavin T fluorescence was attributed to increased Aβ adsorption, not disaggregation.

Conclusions:

• The interpretation of kinetic fibril disaggregation assays in prior publications is invalid.
• Previously reported disaggregase activity in worm or mammalian cell extracts is not supported by this re-evaluation.
• Two prior publications are corrected, and an apology is extended for the misinterpretation of data.