Degree Granting Department
Randy W. Larsen, Ph.D.
Myoglobin, Thermodynamics, Heme proteins, Calixarenes, Photoacoustic calorimetry
Small ligand diffusion in heme proteins is not fully understood. To help better understand CO diffusion, three systems were investigated: L29H/F43H site-directed sperm whale myoglobin, horse heart myoglobin in a heavy water buffer, and calixresorcinarene. Binding of copper to calixresorcinarene was photophysically characterized to unravel transient binding of small molecules in heme-copper proteins. Copper binding was found to have a low dissociation constant of approximately 8.6 micrometers.. Reaction profiles using photoacoustic calorimetry were constructed for the myoglobin systems. In deuterium oxide, ligand escape is not rate limited by water entry. Large enthalpy differences arise from the thermodynamic properties of deuterium oxide and the extensive hydrogen bonding network in myoglobin. In the mutant, CO rebinds primarily to the heme and is exothermic with a large volume contraction because of altered electrostatics within the binding pocket and higher water occupancy.
Scholar Commons Citation
Small, Meagan, "Photothermal studies of carboxymyoglobin" (2010). Graduate Theses and Dissertations.