The Chemistry of Life Processes Program in the Chemistry Division of NSF is funding Dr. William Pomerantz from the University of Minnesota to develop nuclear magnetic resonance methods of fluorine detection to study interactions between proteins. The research and educational goals in the Pomerantz lab address long-standing questions about biomolecular communications between proteins, drawing from findings in the disciplines of both chemistry and biology. Proteins termed transcription factors are the master regulators of cellular function. They facilitate the complicated transfer of information that specifies how the DNA code is used to make proteins. This research seeks to understand the details of the interactions between proteins and their underlying biology. The element fluorine will be used as a sensitive reporter for difficult-to-detect interactions at protein interfaces. This method is advantageous in view of fluorine's unique spectroscopic properties and its absence in natural biological molecules. Given the importance of transcription factors, this fluorine-based approach for studying protein-ligand interactions could significantly increase the repertoire of new protein targets for study and thereby open up avenues for improving the understanding of a wide variety of protein function. This project will include training for students with no prior experience of working at the chemistry/biology interface and will engage the Osher Life-Long Learning community's interests in science literacy and the role of chemical biology in science and technology.
This research project is focused on the development of fluorine nuclear magnetic resonance spectroscopy (NMR) methods for detecting, quantifying, and defining novel modes of interactions at transcription factor-protein interfaces that include epigenetic regulatory proteins. Due to the enrichment of aromatic amino acids at protein-binding sites, multiple labeling strategies for sequence selective incorporation of fluorinated aromatic amino acids will be evaluated for reporting on protein binding interactions. The hyper-responsiveness of the fluorine nucleus to changes in chemical environment leads to simplified 1D-biomolecular NMR spectra that can be rapidly acquired and readily interpreted. This method will be evaluated against known ligands to characterize their mode of interaction and also in discovery format using small molecule libraries. These studies will be extended to acquiring mechanistic information under physiological conditions by in-cell fluorine-19 NMR. The origins of cellular uptake of fluorine-labeled peptide macrocylces will be investigated using lanthanide shift reagents for differentiating extracellular versus internalized peptides. This fluorine-19 NMR method will set the stage for use as a structure-based tool to find new chemical probes for challenging protein-protein interactions. Given the importance of transcription factors, the proposed fluorine-19 NMR approach to study protein-ligand interactions could significantly increase the repertoire of new protein targets opening up avenues for improving the understanding of their biology.
