Artificial Antennas: Thermodynamics of Protein-DNA, Protein-Solid, and Protein-Dye Interactions for Light Harvesting Applications

The thermodynamics of protein-DNA and protein-solid interactions have been investigated here. Protein-DNA interactions play fundamental roles in biological systems and disease. Therefore, studies that help explain the mechanisms of these interactions will contribute to the development of much needed drug therapies. Protein-solid interactions have been optimized for applications in drug delivery and biomedical devices. Additionally, protein-DNA and protein-solid interactions have been optimized as matrices for artificial light harvesting antennas with the goal of utilizing sunlight for energy conversion. In this thesis, glucose oxidase/DNA (GOx/DNA) was used as a model system to study the role of protein surface charge in the thermodynamics of protein-DNA interactions. Synthesis of differentially charged GOx analogs facilitated control of its net charge and revealed a protein/DNA switching mechanism where binding is switched on at a GOx charge of +30. Another goal of this thesis was to study the contribution of protein surface charge to the thermodynamics of protein/solid interactions using a GOx/zirconium phosphate (GOx/α-ZrP) model system. Negatively charged GOx analogs associated weakly with α-ZrP but positively charged analogs associated with high affinity and there was a significant linear relationship between GOx net charge and GOx/α-ZrP binding affinity. In a third study, another protein, bovine serum albumin (BSA) was incorporated into a BSA/DNA matrix. A biodegradable BSA/DNA/dyes antenna that harvested light in the broad range from 350 nm to 590 nm was synthesized by self-assembly. Cascade energy transfer that shuttled photons to a terminal acceptor emitting red light for the potential catalysis of solar cells was characterized