Development of Protein Crystal-Polymer Hybrids: A New Class of Functional Materials
Abstract
The overarching goal of this research program is to develop a new class of materials, termed polymer-integrated crystals (PIX). PIX will uniquely combine the structural order and coherence of molecular crystals, the flexibility and responsiveness of synthetic polymers, and the chemical/structural versatility of proteins. In doing so, these new materials will provide a new platform for fundamental studies of self-assembly at the interface of polymer chemistry, materials science and structural biology, and enable new modalities in adaptive/self-healing materials, sensing/detection applications and catalysis. The simultaneous presence of structural order and flexibility/adaptiveness/dynamism is a key design principle for the construction of advanced materials. There are many biological (e.g., microtubules, flagella, viruses) and synthetic assemblies (e.g., dynamic molecular crystals and frameworks) that can undergo considerable structural transformations without losing their crystalline order, leading to remarkable mechanical properties with utility in diverse applications ranging from selective sorption and separation to sensing and mechanoactuation. Ultimately, however, the extent of structural changes by such flexible crystalline materials and their elasticity are constrained by the necessity to maintain a continuous network of bonding interactions between the constituents of the lattice. In order to overcome this limitation, we recently introduced the concept of PIX whereby the mesoporous crystals of the protein ferritin were merged with synthetic, poly-acrylate polymers. Proof-of-principle experiments demonstrated that the ferritin crystals-polymer hybrids displayed unprecedent emergent properties such as reversible expansion/contraction and self-healing without losing crystallinity. In the process, they overcame a fundamental limitation of condensed matter: that ordered materials are inflexible and brittle, and flexible/adaptive materials lack substantial order. Using these paradigm-shifting findings as a springboard, our goal in the proposed project is to establish general design principles for PIX, and to create new PIX with tailorable structural and mechanical properties. This will be accomplished through two Thrusts, which will uniquely combine protein biochemistry and organic synthesis with advanced strategies for protein structure/materials characterization and controlled polymer growth. Thrust 1: Establish the compositional scope of ferritin-PIX and elucidate how molecular-level interactions control macroscopic-level properties. Through a systematic study of a library of ferritin variants and synthetic polymers, we will establish general design/construction principles for PIX. Thrust 2: Broaden the compositional, structural and functional scope of PIX. We will use strategies for the controlled growth of polymers and crystal lattices of various proteins a) construct PIX with tailorable materials properties and b) to examine the scope and generalizability of PIX. With its expansive scope that encompasses Òpolymer synthesis, supramolecular assembly, and macromolecular hierarchyÓ, Òdesign and synthesis of self-assembled systems with responsive behaviorsÓ and Òintegration of biological systems with synthetic systemsÓ, the proposed program builds a bridge between several ARO programs including Polymer Chemistry, Reactive Chemical Systems and Biochemistry/Biomolecular Assembly and Organization.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 21, 2019
- Source ID
- W911NF1910228
Entities
People
- Faik Tezcan
Organizations
- Army Contracting Command
- United States Army
- University of California, San Diego