Anionic lipid vesicles have differential effects on the aggregation of early onset-associated α-synuclein missense mutants

Structural characterisation of α-synuclein-membrane interactions and the resulting aggregation using small angle scattering

The presence of amyloid fibrils is a hallmark of several neurodegenerative diseases. Some amyloidogenic proteins, such as α-synuclein and amyloid β, interact with lipids, and this interaction can strongly favour the formation of amyloid fibrils. In particular the primary nucleation step, i.e. the de novo formation of amyloid fibrils, has been shown to be accelerated by lipids. However, the exact mechanism of this acceleration is still mostly unclear. Here we use a range of scattering methods, such as dynamic light scattering (DLS) and small angle X-ray and neutron scattering (SAXS and SANS) to obtain structural information on the binding of α-synuclein to model membranes formed from negatively charged lipids and their co-assembly into amyloid fibrils. We find that the model membranes take an active role in the reaction. The binding of α synuclein to the model membranes immediately induces a major structural change in the lipid assembly, which leads to a break-up into small and mostly disc- or rod-like lipid-protein particles. This transition can be reversed by temperature changes or proteolytic protein removal. Incubation of the small lipid-α-synuclein particles for several hours, however, leads to amyloid fibril formation, whereby the lipids are incorporated into the amyloid fibrils.

Cerium oxide nanoparticles modulating the Parkinson's disease conditions: From the alpha synuclein structural point of view and antioxidant properties of cerium oxide nanoparticles

Parkinson's and Alzheimer's disease is the main cause of dementia, which is associated with the progressive deterioration of the intelligence and senses. Free radicals are created during oxidative stress in cells, which are considered one of the destructive factors in neurodegenerative diseases. In this study, the antifibrillar and antioxidant properties of cerium oxide nanoparticles (CeO2 NPs) were investigated experimentally and theoretically. The CeO2 NPs were synthesized and analyzed to reveal the physicochemical and biological properties. The results showed that the CeO2 NPs have unique properties with potent antioxidant activities. The experimental and computational studies showed that the CeO2 NPs interact with the active site of Alpha-synuclein. The existence of hydrogen bonding between O atoms of CeO2 NPs and N-H of adjacent acid amines and the equilibrium distances were confirmed by 1.751 (Leu100), 1.786 (Gln99) and 2.213 Å (Lys97). The minimum free energy binding of L-DOPA drug (as positive control) and CeO2 NPs were negative, resulting interaction between compounds and protein. As a result, these compounds inhibited Alpha-synuclein protein aggregation. In addition, that CeO2 NPs strongly binds with receptor by relative binding energy as compared with L-DOPA drug. These findings revealed that CeO2 NPs prevent Alpha-synuclein fibrillation and can be applied as nano-drug against the Parkinson's disease.