Proteins are a class of nanoscale building block with remarkable chemical complexity and sophistication: their diverse functions, shapes and symmetry, and atomically monodisperse structures far surpass the range of nanoparticles that can be accessed synthetically. The chemical topology of proteins that drive their assembly into higher order materials are central to their functions in Nature. However, despite the importance of protein-based materials in biology, efforts to harness these building blocks synthetically to engineer new materials have been impeded by the chemical complexity of protein surfaces, which make it difficult to reliably design proteins that predictably assemble into targeted materials. In this dissertation, this challenge is addressed by introducing programmable nucleic acid interactions on protein surfaces and investigating the various parameters that can be used to control the types and structure of protein materials that can be made from them. The first chapter provides a detailed historical background of the discovery and engineering of natural and synthetic protein- and DNA-based materials. In the second chapter, protein monomers that possess a single DNA modification are discussed, and the ability of the structure of this DNA to influence the pathway of protein polymerization between step- and chain-growth is explored. Chapter Three deals with the design and study of bivalent proteins where cooperative binding between pairs of DNA strands can drive 1D protein assembly with well-defined orientational order. In the fourth chapter, the assembly of a variety of proteins that are densely functionalized with nucleic acids is explored, and we establish that DNA can direct the crystallization of proteins into 3D superlattices. Chapter Five investigates how the spatial distribution of DNA, which can be modulated through the heterogenous but well-defined chemical topology of proteins, can be harnessed to control protein crystallization behavior. To conclude, Chapter Six summarizes the concepts explored in previous chapters, which form the basis for future work ranging from the synthesis of functional hydrogels that exhibit tunable mechanical properties, to answering fundamental questions about the nature of DNA-modified nanostructures. Overall, this work provides a comprehensive understanding of how DNA modifications on the surface of proteins can be exploited to control the structure of protein materials, where DNA and protein sequence, and the mode of conjugation, work in concert to dictate material structure.

Creator

• McMillan, Janet

DOI

• https://doi.org/10.21985/n2-03by-9k95

Subject

• Chemistry

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:14624
• etdadmin_upload_662062

Date created

• 2019-01-01

Resource type

• Dissertation

Rights statement

• In Copyright