9630474 Karplus A question central to flavoenzyme studies is how the binding of FMN or FAD to various protein scaffolds controls the redox potential and chemical reactivity of the flavin, allowing it to catalyse an astounding diversity of reactions. High resolution structural information, combined with extensive enzymatic and spectroscopic data is the most effective way to gain insight into the mechanisms controlling flavin reactivity. This project extends studies of recombinant forms of the flavoenzymes ferredoxin-NADP+ reductase (FNR), old yellow enzyme (OYE), and Mycobacterium smegmatis lactate monooxygenase (LMO). Studies on OYE include high resolution analyses of the wild type and mutant OYE structures and, in particular, determining how NADPH binds to OYE and how much charge transfer interactions contribute to ligand affinity. Other studies include the structural analyses of wild type and mutant forms of spinach FNR, pea FNR and corn root FNR, as well as LMO. %%% Enzymes which require riboflavin are widely involved in metabilic processes. A question central to understanding these enzymes is how the binding of riboflavin derivatives (FMN and FAD) to various protein scaffolds controls the redox potential and chemical reactivity of the flavin, and allows the catalysis an astounding diversity of reactions. High resolution structural information, combined with extensive enzymatic and spectroscopic data is the most effective way to gain insight into the mechanisms controlling flavin reactivity. This project uses crystallographic and other biophysical studies to further the understanding of structure-function relations for the flavin dependent enzymes ferredoxin-NADP+ reductase, old yellow enzyme, and lactate monooxygenase. ***
