Understanding Self-assembly of Silica Precipitating Peptides to Control Silica Particle Morphology.

The most advanced materials are those found in nature. These evolutionary optimized substances provide highest efficiencies, e.g., in harvesting solar energy or providing extreme stability, and are intrinsically biocompatible. However, the mimicry of biological materials is limited to a few successful applications since we still lack the tools to recreate natural materials. Herein, we provide such means based on a peptide library derived from the silaffin protein R5 that enables rational biomimetic materials design. It is now evident that biomaterials do not form via mechanisms observed in-vitro. Instead, the material's function and morphology are predetermined by precursors that self-assemble in solution, often from a combination of protein and salts. These assemblies act as templates for biomaterials. The RRIL peptides used here are a small part of the silica precipitation machinery in diatoms. By connecting RRIL motifs via varying central bi- or trifunctional residues, we generated a library of stereoisomers, which allowed us to characterize different template structures in the presence of phosphate ions by combining residue-resolved real-time nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) simulations. Understanding these templates in atomistic detail, we were able to control the morphology of silica particles via manipulation of the template precursors. This article is protected by copyright. All rights reserved.