Plenary Session Featuring The Fred Kavli Distinguished Lectureship in Materials Science

Emulating Nature’s Way of Making Materials

Abstract

From harvesting solar energy, to purifying water, to capturing CO₂, living organisms have solved some of the most vexing challenges now facing humanity. They have done so by creating a vast library of proteins that can assemble into hierarchical structures to control the transport and transformation of matter and energy and direct the mineralization of inorganic components. While the high information content contained within the intricate sequences of proteins is crucial for accomplishing these tasks, assembly and mineralization are nonetheless constrained to proceed according to the physical laws that govern all such processes. Thus, the ability to design proteins at will, combined with an understanding of the mechanisms by which biological systems successfully manipulate those laws to create hierarchical materials, is ushering in an era of materials design to address our most pressing technological challenges, which extend far beyond those faced during the evolution of modern organisms. In this talk, we present the results of recent research to create proteins that assemble into 2D and 3D structures, create coherent interfaces with inorganic materials and direct mineral nucleation and growth. In contrast to traditional protein engineering efforts, which have focused on modifying naturally occurring proteins, we describe the design of new proteins from scratch to optimally solve the problem at hand. Increasingly, we develop and use deep learning methods to design amino acid sequences that are predicted to fold to desired structures with targeted functions. We produce synthetic genes encoding these sequences and characterize the resulting structures experimentally. We then utilize in situ methods to directly observe interfacial structure, protein self-assembly and nanocrystal formation in these systems. The findings demonstrate the versatility and fidelity of our approach to protein design, while revealing the importance of surface charge, facet-specific binding, solvent organization and, more generally, the balance of protein-substrate-solvent interactions in determining how organized protein-based materials emerge. These results demonstrate the vast potential of protein design in materials science and elucidate the mechanisms by which the interactions between biomolecules and materials lead to unique materials and morphologies.