This POWRE award is for a 15 month sabbatical for the PI at Brandeis University, working with Professor Dagmar Ringe's group on enzymatic systems that use pyridoxal phosphate (Vitamin B6) as a cofactor. A quantum mechanical-molecular mechanical model for enzyme-substrate interactions will be developed and applied to the vitamin B6-dependent enzymes alanine racemase and D-amino acid aminotransferase. This project will enable the PI to expand her knowledge in the biochemical and biomedical areas and develop a research program in these areas. The project is also designed to enhance our understanding of how enzymes perform their functions as catalysts.