CAREER: Supramolecular Light-Harvesting Materials from Self-Assembly of Bio-Inspired Macromolecules

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

ID: MPS/DMR/BMAT(7623) 1149067 PI: Horne, William ORG: University of PIttsburgh Title: CAREER: Supramolecular Light-Harvesting Materials from Self-Assembly of Bio-Inspired Macromolecules INTELLECTUAL MERIT: The design of chemical species that mimic functions carried out by proteins involved in photosynthesis is a frontier challenge in materials science. Underlying this challenge is the requirement to create defined molecular entities on the 10-100 nm size scale that accurately position arrays of functional groups with sub-nm spatial precision. There is an unmet need for a design paradigm that combines (1) the complete structural control offered covalent bond-by-bond chemical synthesis with (2) the efficiency and large structures achievable by non-covalent self-assembly. The overall objective of this project is to develop a platform for the construction of supramolecular biomaterials with tunable properties based on the self-assembly of protein-based building blocks in aqueous solution. The protein-folding motif that will be used to direct monomer self-assembly is the alpha-helical coiled coil. Prior studies on the relationship between sequence and folding pattern have led to a thorough understanding of the basic principles for the design of coiled-coil proteins. This rich knowledge base will be exploited to create a family of subunits that self-assemble to form defined 1-dimensional linear arrays or 2-dimensional networks. These materials will be applied in the preparation of light-harvesting chromophore arrays that mimic the antenna function of natural photosynthetic proteins. The fundamental principles elucidated in the course of this research will be the foundation of a general strategy for the design and construction of protein-based supramolecular assemblies. Moreover, the light-harvesting materials will provide a model system for the study and mimicry of energy delocalization in biological antenna arrays. BROADER IMPACTS: The problem addressed in this project has important societal implications. The development of a sustainable supply of clean energy is one of the most significant scientific challenges facing humanity in the 21st century. There is no simple technological solution to this daunting task; however, the research proposed seeks to help define physicochemical principles upon which such technology will rely. Development of the light-harvesting materials that are the ultimate goal of this project will improve understanding of photosynthetic energy transduction in nature and the requirements to effectively mimic photosynthetic proteins with designed chemical species. The interdisciplinary research program will provide a fertile training ground for students at multiple levels and from diverse educational backgrounds. An education and outreach plan is included that aims to engage research-active undergraduates with a class aimed at teaching the effective oral communication of scientific results. The course will foster outreach through organized opportunities for enrolled students to present their work to peers as well as to high-school students from the local community. The proposed program will (1) enhance the competitiveness of STEM undergraduates at the University of Pittsburgh by addressing an unmet need in the existing curriculum and (2) engage potential future STEM majors, including underrepresented minorities, by enabling participating students to act as near-peer role models for opportunities to pursue undergraduate scientific research.