The proposed research will investigate the dynamics of hemoglobin using time-resolved spectroscopies and computer modeling in order to help determine the molecular mechanism of cooperativity in oxygen binding. This knowledge was intended to be useful for understanding and developing treatments for hemoglobin disorders, for aiding in the design of blood substitutes, and for the understanding of allosteric proteins in general. Important molecular interactions involved in the R to T transition of hemoglobin will be probed using both transient ultraviolet resonance Raman and Fourier transform spectroscopies. The structural information available from the experimental studies will then be used as constraints in various computer simulations aimed at determining intermediate structures and the dynamics of the R to T transition.