CARNEGIE MELLON UNIVERSITY
The ultimate goal of our research supported by R01GM084614 (?Biophysical & Molecular Biological Studies of Hemoglobin?) is to provide a detailed structural and dynamic description of how O2 binding to one subunit of the hemoglobin (Hb) molecule can alter the accessibility and reactivity of the heme-iron atoms in the adjacent subunits. The objective for our request for an administrative supplement through the Recovery Act Funds for Administrative Supplements is to accelerate the tempo of our current research. We requested supplemental funding to speed up Specific Aim #3, namely to investigate the effects of allosteric effectors (H+ ions and organic phosphates) on the proximal geometry and distal accessibility of the heme-iron atoms to describe the structural basis behind the Bohr effect and the effect of organic phosphates. Specifically, we would like to investigate (i) the effect of the pH, allosteric effector, and temperature on the stability of the H-bonds between the oxygen ligands and the histal histidyl residues of the ?-chain and ?-chain, (ii) the effect of the heme environment on the stability of the heme iron against auto-oxidation, and (iii) to carry out additional structural and dynamic studies of Hb A and mutant Hbs by NMR. The knowledge that we shall gain can also provide insights into the development of a new generation of Hb-based oxygen carriers. Hb research is a good illustration of how discoveries from basic research on proteins can make important contributions to medicine and biotechnology.