Designing Two-Dimensional Protein Arrays through Fusion of Multimers and Interface Mutations

Area of Science:

• Biomolecular Engineering
• Materials Science
• Nanotechnology

Background:

• Protein self-assembly is a key strategy for creating ordered nanostructures.
• Designing protein interfaces to control assembly and avoid clashes is challenging.
• Cyclic symmetry and alanine substitutions offer potential solutions for predictable protein structures.

Purpose of the Study:

• To engineer proteins that self-assemble into 2-D arrays.
• To utilize cyclic symmetry and alanine substitutions to control protein structure and assembly.
• To demonstrate the formation of ordered hexagonal protein lattices.

Main Methods:

• Protein design incorporating cyclic symmetry and alanine substitutions.
• Induction of self-assembly using calcium ions.
• Characterization using transmission electron microscopy (TEM), atomic force microscopy (AFM), small-angle X-ray scattering (SAXS), and fluorescence microscopy.

Main Results:

• Successfully designed proteins that self-assemble into 2-D arrays upon calcium ion addition.
• Characterized hexagonal lattices with p3 space group symmetry and 7.25 nm periodicity.
• Observed self-assembled structures exceeding 100 μm in characteristic length.
• Lattices were approximately 5 nm in height.

Conclusions:

• The developed strategy enables the creation of highly ordered, large-scale 2-D protein arrays.
• The combination of cyclic symmetry and alanine substitutions is effective for controlling protein self-assembly.
• This approach provides a versatile platform for engineering functional 2-D nanostructured materials.