CAREER: Synthetically Modified Tobacco Mosaic Virus: A Versatile Scaffold for Nanoscale Materials

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

With the support of the Organic Dynamics Program in the Chemistry Division, Professor Matthew Francis of the University of California- Berkeley will work with the tube-like capsid of the tobacco mosaic virus (TMV), which provides an extremely promising template for the construction of nanoscale materials. Each particle is 300 nm in length and is made of 2100 identical protein subunits that could orient optical and electronic components into wire-like assemblies. However, the covalent attachment of new functionality to the capsid has been difficult to achieve, in part because the amino acid side chains commonly targeted by bioconjugation reactions are not found on the surface after assembly. To address this challenge, Professor Francis has developed chemically orthogonal synthetic methods that can install small molecules on the exterior capsid surface, the surface lining the hollow core, or at either end of the capsid helix. Taken together, these modification reactions render TMV one of the most versatile building blocks available for the construction of nanoscale materials. The use of biomolecules for the construction of nanoscale materials represents a major paradigm shift in device fabrication, and as a result many new challenges have emerged. In particular, the incorporation of polymers, inorganic materials, and other functional components into the assemblies has been difficult to achieve. A key component of these studies is the solubilization of protein assemblies in organic solvents to address these challenges. This represents many new avenues for protein modification and is a highly promising way to stabilize protein secondary and tertiary structure. It is also a significant advancement in the preparation of protein-based Langmuir-Blodgett films, which are often prohibited by the water solubility associated with most proteins. When combined with AFM and other surface characterization techniques, these new tools will also provide a versatile experimental platform with which to study biomolecule aggregation. The Organic and Macromolecular Chemistry Program supports Professor Matthew Francis of the University of California- Berkeley whose research, it is anticipated, will yield fundamental insight into the use of biomolecules for materials synthesis, and the particular emphasis on protein-based structures will complement the applications for which DNA can be used. The greatest impact of the proposed research program is the unique training environment it will provide for graduate students and undergraduates. All students will combine organic synthesis, physical organic chemistry, and transition metal chemistry with the expression, purification and characterization methods associated with proteins. The students will possess a diverse set of technical skills and will be capable of solving interdisciplinary problems at the interface of chemistry and biology. Professor Francis will attempt to impact the community through a special effort to inform non-scientists about nanotechnology. He will implement a vigorous lecture series to be given at Rotary Clubs and other local organizations with the goal of describing the profound benefits of nanotechnology. Similar talks will be given at high schools in the local community.