Using myoglobin models of oxidases for mechanistic understanding of the oxygen reduction reaction

Using state-of-the art time resolved structural methods like XFEL and a set of newly designed myoglobin modes, I have set out to understand aspects of the oxygen reduction reaction in metalloenzymes that have remained elusive. There are many pathways for the oxygen reduction reaction to take place in metalloenzymes like oxidases, but strangely, there is a high degree of variance in the active site of these enzymes. Studying the native enzymes has proven difficult using traditional methods due to the insoluble nature of oxidases along with many complicating features like multiple heme and transition metal binding sites. These issues complicate mechanistic studies due to replicating native function as transmembrane proteins and spectroscopy techniques because of the interference with the active site. I will show the benefits of using structural analogs of three oxidase active sites – each with unique and poorly understood features. Crystallographic techniques and XFEL have been used to answer outstanding questions in the field regarding short-lived intermediates in heme copper oxidases and the role of heteronuclear metal active sites. Cytochrome bd oxidase models have been used to make sense of many interesting – but isolated – observations of these peculiar enzymes. These studies come at a serendipitous time for cytochrome bd oxidases, as a recent discovery has made experts in this field rethink much of what they thought they knew about how this enzyme functions in organisms besides E. coli. It is my hope to fill some of those gaps and provide context for this reevaluation.LimitedAuthor requested closed access (OA after 2yrs) in Vireo ETD syste