The Poulos lab focuses primarily on structure-function relationships in heme-containing enzymes and related proteins. The heme group is found in a variety of proteins including electron transferring cytochromes, oxygen storage and delivery in the globins, and heme-containing enzymes. Although each of these proteins uses exactly the same heme group, each exhibits very different functions. Therefore, a detailed understanding of heme proteins provides important information on how the protein modulates the activity of a small molecule, in this case heme. While our main tool is x-ray diffraction, we also employ a variety of other approaches including various spectroscopies and computational biochemistry. An active area of interest is structure based drug design with our current target being nitric oxide synthase. This effort has resulted in the development novel compounds with some rather promising in vivo effects in the treatment of neurodegenerative disorders.