Assembly of a patchy protein into variable 2D lattices via tunable multiscale interactions

Area of Science:

• Biomaterials Science
• Nanotechnology
• Protein Engineering

Background:

• Living systems utilize molecular self-assembly for functional complexity.
• Proteins offer advantages as nanoscale building blocks (monodispersity, tunable interactions).
• Controlling protein self-assembly is challenging compared to inorganic/polymeric nanoparticles.

Purpose of the Study:

• To achieve modular self-assembly of engineered proteins into precisely patterned 2D crystals.
• To demonstrate control over protein assembly across multiple length scales (Ångström to nanometers).
• To link observed structures to the free-energy landscape of assembly.

Main Methods:

• Engineering a single, highly patchy protein.
• Utilizing four classes of interactions to direct assembly.
• In-situ atomic force microscopy (AFM) for observing assembly.
• Thermodynamic analyses of protein-protein and protein-surface interactions.

Main Results:

• Successfully assembled an engineered protein into four distinct 2D crystal structures.
• Demonstrated control over assembly by manipulating interactions across multiple length scales.
• Related the observed phase behavior to the underlying free-energy landscape.
• Observed rich phase behavior from a single protein scaffold.

Conclusions:

• Modular control of protein self-assembly is achievable by exploiting interactions across multiple length scales.
• Engineered proteins can form precisely patterned 2D crystals.
• This approach predicts unusual bulk properties for protein-based materials.