Genetic Engineering of Oxygen Affinity of Bacterial Hemoglobin: Effects on Hemoglobin Structure, Respiration, and Other Cellular Processes

Illinois Institute Of Technology, Chicago IL

Investigators

Abstract

9910356 Webster Vitreoscilla produces hemoglobin that displays an unusually high rate of oxygen dissociation. Although the function of VHb in its natural host is not known, evidence suggests that it facilitates respiration under hypoxic conditions by funneling oxygen to the terminal oxidases. Biophysical characteristics and oxygen binding properties of selected mutants of VHb will be analyzed. The crystal structure of hemoglobin (VHb) obtained from the aerobic bacterium Vitreoscilla is available thus facilitating this research. These studies will help assess whether predicted structural changes from each of the site-directed mutations have occurred and how changes in the oxygen binding affinity alter respiratory activity and oxygen metabolism of microbial systems. VHb function in the native organism will be evaluated also using a vgb (gene) knockout mutation (to eliminate VHb) to determine the role of VHb on growth, respiration and ATP synthesis, especially under hypoxic conditions.