An Efficient Procedure for Removal and Inactivation of Alpha-Synuclein Assemblies from Laboratory Materials

Abstract

Background: Preformed α-synuclein fibrils seed the aggregation of soluble α-synuclein in cultured cells and in vivo. This, and other findings, has kindled the idea that α-synuclein fibrils possess prion-like properties.

Objective: As α-synuclein fibrils should not be considered as innocuous, there is a need for decontamination and inactivation procedures for laboratory benches and non-disposable laboratory material.

Methods: We assessed the effectiveness of different procedures designed to disassemble α-synuclein fibrils and reduce their infectivity. We examined different commercially available detergents to remove α-synuclein assemblies adsorbed on materials that are not disposable and that are most found in laboratories (e.g. plastic, glass, aluminum or stainless steel surfaces).

Results: We show that methods designed to decrease PrP prion infectivity neither effectively remove α-synuclein assemblies adsorbed to different materials commonly used in the laboratory nor disassemble the fibrillar form of the protein with efficiency. In contrast, both commercial detergents and SDS detached α-synuclein assemblies from contaminated surfaces and disassembled the fibrils.

Conclusions: We describe three cleaning procedures that effectively remove and disassemble α-synuclein seeds. The methods rely on the use of detergents that are compatible with most non-disposable tools in a laboratory. The procedures are easy to implement and significantly decrease any potential risks associated to handling α-synuclein assemblies.

Keywords: Alpha synuclein; Parkinson’s disease; cleaning procedures; detergent; fibrils; inactivation; removal.

Fig.1

Efficiency of different cleaning solutions to remove α-Syn assemblies from different surfaces. Quantification of the remaining Atto-550 labeled oligomeric, A, α-Syn fibrils, B and α-Syn ribbons, C, spotted and dried on plastic, glass, aluminum and stainless steel surfaces, previously scraped with sandpaper, using a fluorescence imager after cleaning with the different solutions. Error bars represent standard error (SE) (n = 4 independent measurements) performed in quadruplicates. The measured fluorescence data from imaging are presented as averages±standard error in Supplementary Table 1, panels A, B, C and C’.

Fig.2

Quantitative assessment of the fraction of fibrillar α-Syn solubilized in the different cleaning solutions. The fraction (%) of α-Syn fibrils, A and ribbons, B, that becomes soluble relative to the initial total amount of fibrillar α-Syn in the cleaning solution was determined following ultracentrifugation by measurement of the absorbance of fluorescently labeled α-Syn in the supernatant fraction as described in the material and methods section. Error bars represent standard error (SE) (n = 4 independent measurements) performed in quadruplicates. The measured absorbance data are presented as averages±standard error in Supplementary Table 1, panels D and E.