The unifying theme of our research activities in the past few years has centered around the development of methodology for the study of structure-function relationships in heme containing proteins.
Hemoproteins play a crucial role in maintaining life in essentially all living organisms.
Examples of these proteins include the oxygen carriers hemoglobin and myoglobin, in which the heme active center is used by the protein as an oxygen binding site. Cytochrome, on the other hand, are electron transfer heme proteins in which the heme active site is shuttled between different oxidation states in order to accept or donate electrons in the cycle of respiration. How exactly does nature tune the redox properties of the ubiquitous heme within a given protein so that the resultant activity is that of oxygen binding, or, electron transport at a variety of different potentials, is a main theme of our research efforts. As part of our research, we have developed a biosynthetic method that allows the selective 13C labeling of atoms in the heme active site. The biosynthetic method is based on the overexpression of a heme containing protein, cytochrome b5, in Escherichia coli.