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Self-assembly and modular functionalization of three-dimensional crystals from oppositely charged proteins.

Liljeström V, Mikkilä J, Kostiainen MA - Nat Commun (2014)

Bottom Line: Well-developed, especially DNA-based, methods for their preparation exist, yet most techniques concentrate on molecular and synthetic nanoparticle systems in non-biocompatible environment.Here we describe the self-assembly and characterization of binary solids that consist of crystalline arrays of native biomacromolecules.Importantly, the whole preparation process takes place at room temperature in a mild aqueous medium allowing the processing of delicate biological building blocks into ordered structures with lattice constants in the nanometre range.

View Article: PubMed Central - PubMed

Affiliation: 1] Biohybrid Materials Group, Department of Biotechnology and Chemical Technology, Aalto University, 00076 Aalto, Finland [2] Molecular Materials Group, Department of Applied Physics, Aalto University, 00076 Aalto, Finland.

ABSTRACT
Multicomponent crystals and nanoparticle superlattices are a powerful approach to integrate different materials into ordered nanostructures. Well-developed, especially DNA-based, methods for their preparation exist, yet most techniques concentrate on molecular and synthetic nanoparticle systems in non-biocompatible environment. Here we describe the self-assembly and characterization of binary solids that consist of crystalline arrays of native biomacromolecules. We electrostatically assembled cowpea chlorotic mottle virus particles and avidin proteins into heterogeneous crystals, where the virus particles adopt a non-close-packed body-centred cubic arrangement held together by avidin. Importantly, the whole preparation process takes place at room temperature in a mild aqueous medium allowing the processing of delicate biological building blocks into ordered structures with lattice constants in the nanometre range. Furthermore, the use of avidin-biotin interaction allows highly selective pre- or post-functionalization of the protein crystals in a modular way with different types of functional units, such as fluorescent dyes, enzymes and plasmonic nanoparticles.

No MeSH data available.


Related in: MedlinePlus

Protein-based materials used to form electrostatic binary solids.(a) Native CCMV and (b) avidin. From left to right: particles drawn to scale, calculated electrostatic surface potential, location and geometry of patches, TEM image of negatively stained CCMV (scale bar, 50 nm) and DLS measurements of avidin and CCMV (volume-weighted size distribution).
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f1: Protein-based materials used to form electrostatic binary solids.(a) Native CCMV and (b) avidin. From left to right: particles drawn to scale, calculated electrostatic surface potential, location and geometry of patches, TEM image of negatively stained CCMV (scale bar, 50 nm) and DLS measurements of avidin and CCMV (volume-weighted size distribution).

Mentions: Biological building blocks, such as protein cages (for example, CCMV and ferritins) and avidin (Fig. 1), are widely used in nanotechnology and biotechnological applications3031. Protein cages can effectively constrain and template the formation of nanoparticles3233. Owing to their highly monodisperse structure, protein cages also readily form ordered arrays on solid supports or interfaces3435. Furthermore, we have shown that protein cages can form free-standing crystals or crystalline assemblies in solution with the help of synthetic binding agents363738. CCMV consists of 180 identical coat protein subunits that encapsulate the RNA genome to yield a T=3 viral particle ~28 nm in diameter, which exhibits large negatively charged patches around the 60 pores present in the centre of the threefold quasi-icosahedral rotation axes (Fig. 1a). On the other hand, avidin is a tetrameric glycoprotein (Mw 68 kDa) that binds biotin with extreme selectivity and affinity. This ability has allowed avidin and its derivatives to become an important tool in many biochemical techniques, including biomolecule detection, interaction studies and purification. Avidin has a maximum cross-section of 7.2 nm and hydrodynamic diameter of 5.4 nm measured by dynamic light scattering (DLS; Fig. 1b). The four positively charged patches are arranged in tetrahedral geometry. The characteristics of the patchy electrostatic potential map of avidin can be described as a rigid tetrahedron with four positive patches in the corner points of the tetrahedron ~5.1 nm apart. Examples from previous studies show that a patchy interaction pattern strongly affects the final structure of self-assembled nanostructures3940414243. Also, the geometrical shape has been shown to guide the self-assembly of non-spherical particles444546.


Self-assembly and modular functionalization of three-dimensional crystals from oppositely charged proteins.

Liljeström V, Mikkilä J, Kostiainen MA - Nat Commun (2014)

Protein-based materials used to form electrostatic binary solids.(a) Native CCMV and (b) avidin. From left to right: particles drawn to scale, calculated electrostatic surface potential, location and geometry of patches, TEM image of negatively stained CCMV (scale bar, 50 nm) and DLS measurements of avidin and CCMV (volume-weighted size distribution).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109007&req=5

f1: Protein-based materials used to form electrostatic binary solids.(a) Native CCMV and (b) avidin. From left to right: particles drawn to scale, calculated electrostatic surface potential, location and geometry of patches, TEM image of negatively stained CCMV (scale bar, 50 nm) and DLS measurements of avidin and CCMV (volume-weighted size distribution).
Mentions: Biological building blocks, such as protein cages (for example, CCMV and ferritins) and avidin (Fig. 1), are widely used in nanotechnology and biotechnological applications3031. Protein cages can effectively constrain and template the formation of nanoparticles3233. Owing to their highly monodisperse structure, protein cages also readily form ordered arrays on solid supports or interfaces3435. Furthermore, we have shown that protein cages can form free-standing crystals or crystalline assemblies in solution with the help of synthetic binding agents363738. CCMV consists of 180 identical coat protein subunits that encapsulate the RNA genome to yield a T=3 viral particle ~28 nm in diameter, which exhibits large negatively charged patches around the 60 pores present in the centre of the threefold quasi-icosahedral rotation axes (Fig. 1a). On the other hand, avidin is a tetrameric glycoprotein (Mw 68 kDa) that binds biotin with extreme selectivity and affinity. This ability has allowed avidin and its derivatives to become an important tool in many biochemical techniques, including biomolecule detection, interaction studies and purification. Avidin has a maximum cross-section of 7.2 nm and hydrodynamic diameter of 5.4 nm measured by dynamic light scattering (DLS; Fig. 1b). The four positively charged patches are arranged in tetrahedral geometry. The characteristics of the patchy electrostatic potential map of avidin can be described as a rigid tetrahedron with four positive patches in the corner points of the tetrahedron ~5.1 nm apart. Examples from previous studies show that a patchy interaction pattern strongly affects the final structure of self-assembled nanostructures3940414243. Also, the geometrical shape has been shown to guide the self-assembly of non-spherical particles444546.

Bottom Line: Well-developed, especially DNA-based, methods for their preparation exist, yet most techniques concentrate on molecular and synthetic nanoparticle systems in non-biocompatible environment.Here we describe the self-assembly and characterization of binary solids that consist of crystalline arrays of native biomacromolecules.Importantly, the whole preparation process takes place at room temperature in a mild aqueous medium allowing the processing of delicate biological building blocks into ordered structures with lattice constants in the nanometre range.

View Article: PubMed Central - PubMed

Affiliation: 1] Biohybrid Materials Group, Department of Biotechnology and Chemical Technology, Aalto University, 00076 Aalto, Finland [2] Molecular Materials Group, Department of Applied Physics, Aalto University, 00076 Aalto, Finland.

ABSTRACT
Multicomponent crystals and nanoparticle superlattices are a powerful approach to integrate different materials into ordered nanostructures. Well-developed, especially DNA-based, methods for their preparation exist, yet most techniques concentrate on molecular and synthetic nanoparticle systems in non-biocompatible environment. Here we describe the self-assembly and characterization of binary solids that consist of crystalline arrays of native biomacromolecules. We electrostatically assembled cowpea chlorotic mottle virus particles and avidin proteins into heterogeneous crystals, where the virus particles adopt a non-close-packed body-centred cubic arrangement held together by avidin. Importantly, the whole preparation process takes place at room temperature in a mild aqueous medium allowing the processing of delicate biological building blocks into ordered structures with lattice constants in the nanometre range. Furthermore, the use of avidin-biotin interaction allows highly selective pre- or post-functionalization of the protein crystals in a modular way with different types of functional units, such as fluorescent dyes, enzymes and plasmonic nanoparticles.

No MeSH data available.


Related in: MedlinePlus