Preparation and Characterization of Stable α-Synuclein Lipoprotein Particles.
J Biol Chem
; 291(16): 8516-27, 2016 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-26846854
ABSTRACT
Multiple neurodegenerative diseases are caused by the aggregation of the human α-Synuclein (α-Syn) protein. α-Syn possesses high structural plasticity and the capability of interacting with membranes. Both features are not only essential for its physiological function but also play a role in the aggregation process. Recently it has been proposed that α-Syn is able to form lipid-protein particles reminiscent of high-density lipoproteins. Here, we present a method to obtain a stable and homogeneous population of nanometer-sized particles composed of α-Syn and anionic phospholipids. These particles are called α-Syn lipoprotein (nano)particles to indicate their relationship to high-density lipoproteins formed by human apolipoproteins in vivo and of in vitro self-assembling phospholipid bilayer nanodiscs. Structural investigations of the α-Syn lipoprotein particles by circular dichroism (CD) and magic angle solid-state nuclear magnetic resonance (MAS SS-NMR) spectroscopy establish that α-Syn adopts a helical secondary structure within these particles. Based on cryo-electron microscopy (cryo-EM) and dynamic light scattering (DLS) α-Syn lipoprotein particles have a defined size with a diameter of â¼23 nm. Chemical cross-linking in combination with solution-state NMR and multiangle static light scattering (MALS) of α-Syn particles reveal a high-order protein-lipid entity composed of â¼8-10 α-Syn molecules. The close resemblance in size between cross-linked in vitro-derived α-Syn lipoprotein particles and a cross-linked species of endogenous α-Syn from SH-SY5Y human neuroblastoma cells indicates a potential functional relevance of α-Syn lipoprotein nanoparticles.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfolipídeos
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Alfa-Sinucleína
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Nanopartículas
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Lipoproteínas HDL
Limite:
Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2016
Tipo de documento:
Article