Biomechanical Design of Elastic Protein Biomaterials: A Balance of Protein Structure and Conformational Disorder

Elastic biomaterials are found across biology where they fulfill diverse load-bearing and energy storage and dissipation functions. This class of biomaterials comprises elastic proteins that provide materials with combinations of extensibility, stiffness, tensile strength, toughness, and viscoelastic properties. Differences in mechanical properties are due in large part to variations in the ratio of secondary structure and conformational disorder of constituent protein monomers, arising from differences in amino acid sequence. This natural diversity provides rich inspiration for the design of elastic biomaterials. Here, we review the relationship between sequence, structure, disorder, and mechanical properties of elastic proteins from natural materials ranging from highly extensible and soft, to mechanically strong and tough. We describe molecular strategies as well as recombinant efforts to design materials with tailored mechanical properties, with the ultimate aim of rationally engineering biomaterials for advanced biomedical applications.