posted on 2021-02-17, 16:06authored byRomeo
C. A. Dubini, Huihun Jung, Chloe H. Skidmore, Melik C. Demirel, Petra Rovó
A major
challenge in developing biomimetic, high-performance, and
sustainable products is the accurate replication of the biological
materials’ striking properties, such as high strength, self-repair,
and stimuli-responsiveness. The rationalization of such features on
the microscopic scale, together with the rational design of synthetic
materials, is currently hindered by our limited understanding of the
sequence–structure–property relationship. Here, employing
state-of-the-art nuclear magnetic resonance (NMR) spectroscopy, we
link the atomistic structural and dynamic properties of an artificial
bioinspired tandem repeat protein TR(1,11) to its stunning macroscopic
properties including high elasticity, self-healing capabilities, and
record-holding proton conductivity among biological materials. We
show that the hydration-induced structural rearrangement of the amorphous
Gly-rich soft segment and the ordered Ala-rich hard segment is the
key to the material’s outstanding physical properties. We found
that in the hydrated state both the Ala-rich ordered and Gly-rich
disordered parts contribute to the formation of the nanoconfined β-sheets,
thereby enhancing the strength and toughness of the material. This
restructuring is accompanied by fast proline ring puckering and backbone cis–trans isomerization at the water–protein
interface, which in turn enhances the elasticity and the thermal conductivity
of the hydrated films. Our in-depth characterization provides a solid
ground for the development of next-generation materials with improved
properties.