Table 1.

Presentation of membrane models used to investigate the basic physical and biochemical role of α-synuclein (α-syn). The artificial membrane systems are used to study the physical interaction of α-syn and lipids. They are classified into two categories according to their three-dimensional organisation: vesicular and planar models. These systems can be created using different types and proportions of phospholipids allowing the study of different binding properties of α-syn.

Membrane Model	Description	Principal Fields of Investigation
Vesicular systems
Micelles	Spherical and monolayer system of amphipathic molecules. Substantial difference with biological membranes.	To identify the conformational change of α-syn domains upon interaction with lipids [42].
Liposomes	Spherical vesicles composed of at least one lipid bilayer and of different sizes and curvatures [43] (1) SUV* of 10–100 nm; (2) LUV* 100 nm; (3) GUV* 1 μm.	To investigate the effect of membrane curvature on α-syn oligomer–membrane interactions based on the size: (1) SUV interaction of α-syn with SV; (2) LUV mimicking cell membrane organelles; (3) GUV α-syn relationship with cell membrane [43].
Planar systems
Lipid monolayer or bilayer	Planar structure composed of one or two layers.	To investigate the interaction between oligomers and membranes and to analyse the effect of α-syn oligomers on membrane disruption [43].
Nanodisc	Planar bilayer structure composed of (1) phospholipids of artificial or cell membrane origin. (2) scaffolding proteins or polymers conferring stability to the system. Size variability from 7 to 50 nm. High similarity to biological membranes.	To allow structuring of disordered proteins, such as α-syn into non-toxic α-helical structures [44].

Legend. α-syn = α-synuclein, GUV* = giant unilamellar vesicles, LUV* = large unilamellar vesicles, SUV* = small unilamellar vesicles, SV = synaptic vesicles.