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CN-GELFrEE - Clear Native Gel-eluted Liquid Fraction Entrapment Electrophoresis
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Coacervates and coaggregates: Liquid-liquid and liquid-solid phase transitions by native and unfolded protein
Kazuki Iwashita1, Akihiro Handa2, Kentaro Shiraki1
1Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.
International Journal of Biological Macromolecules
|August 17, 2018
Summary
Native and unfolded proteins form distinct structures in aqueous solutions. Unfolded proteins aggregate into solid-like coaggregates, while native proteins form liquid-like coacervates, driven by hydrophobic interactions.
Area of Science:
- Biochemistry
- Materials Science
- Protein Chemistry
Background:
- Coacervates are liquid-like self-assemblies of macromolecules.
- Proteins can form coacervates, but their aggregation into solid structures is also common.
- Understanding protein self-assembly is crucial for various applications.
Purpose of the Study:
- To investigate how protein unfolding affects self-assembly into coacervates or coaggregates.
- To compare the structural outcomes of native versus unfolded ovalbumin (OVA) and lysozyme (LYZ).
- To elucidate the role of interaction modes (electrostatic vs. hydrophobic) in protein self-assembly.
Main Methods:
- Proteins (OVA and LYZ) were unfolded by heating.
- Complex formation was studied at pH values between the isoelectric points of the proteins.
- Morphology and state (liquid-like vs. solid-like) of the assemblies were characterized.
Main Results:
- Both native and unfolded OVA and LYZ formed complexes.
- Unfolded proteins showed a greater propensity for complex formation than native proteins.
- Native proteins formed spherical, liquid-like coacervates.
- Unfolded proteins formed amorphous, solid-like coaggregates.
- Hydrophobic interactions were dominant in unfolded protein complexation.
Conclusions:
- Protein unfolding significantly alters self-assembly pathways, favoring solid coaggregates over liquid coacervates.
- Hydrophobic interactions play a key role in the aggregation of unfolded proteins.
- Distinguishing between coacervates and coaggregates provides insights into protein liquid-liquid phase separation versus amorphous aggregation.
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