In silico stress-strain measurements on self-assembled protein lattices

Area of Science:

• Biomaterials Science
• Computational Biophysics
• Protein Engineering

Background:

• Beta-solenoid proteins possess high mechanical strength and functionalization potential.
• These properties make them suitable candidates for constructing advanced biomaterials.
• Applications include two- and three-dimensional scaffolds for tissue engineering and regenerative medicine.

Purpose of the Study:

• To design and simulate two-dimensional (2D) lattices using beta-solenoid proteins.
• To evaluate the mechanical properties, specifically elastic moduli, of these protein lattices.
• To assess the potential of beta-solenoid protein-based structures as robust biomaterials.

Main Methods:

• Development of simulation models for 2D square and honeycomb lattices.
• Covalent linking of spruce budworm antifreeze protein (SBAFP), a beta-solenoid protein, to symmetric protein multimers.
• Molecular dynamics simulations employing periodic boundary conditions to model infinite lattices.
• Straining of lattices and measurement of stress-strain curves to determine bulk and shear elastic moduli.

Main Results:

• Simulations successfully modeled infinite 2D lattices of SBAFP.
• At a strain rate of 0.3 nm ps-1, the protein lattices achieved a bulk modulus of approximately 3 GPa.
• This indicates significant mechanical stiffness comparable to high-performance materials.

Conclusions:

• 2D lattices constructed from beta-solenoid proteins demonstrate substantial mechanical strength.
• These findings confirm that protein-based biomaterials can inherit the exceptional material properties of their constituent protein building blocks.
• Beta-solenoid protein lattices represent a promising avenue for developing strong and functional biomaterials.