Dr. Crumbliss is interested in the function, reactivity and control of transition metals in biological systems. A major emphasis is investigations related to the biochemistry of iron. Through application of in vitro and ex vivo biophysical techniques the Crumbliss group is investigating iron trafficking mediated by proteins and low molecular weight iron carriers (siderophores) in bacterial and mammalian cells. This research is relevant to understanding iron bioavailability, oxidative stress, and the relationship between iron and human health and disease. The redox behavior of various native, mutant and engineered hemoglobins is also under investigation with respect to their role in oxidative stress, signaling and cooperative oxygen transport, and potential application as cell free blood substitutes.