Resonance Raman spectra of heme proteins are highly specific and sensitive, unambiguously     revealing the type, redox, coordination and spin state of a heme group, as well as the interactions/ processes that can modify some of these features.

    Special emphasis in our research is paid to heme copper oxygen reductases, terminal enzymes in the respiratory chains of various bacteria and archeae. Heme-copper oxygen reductases reduce oxygen to water. The catalytic reaction is coupled to the translocation of the protons across the membrane, creating an electrochemical proton gradient that drives ATP synthesis. In spite of the major role of the terminal oxidases in the oxygen consumption by living organisms, the mechanism of their function, the coupling between the redox processes and proton translocation is not well understood yet. A prerequisite for understanding the functioning of these complex multi-center redox enzymes is determination of individual midpoint potentials and their possible coupling.
   SERR spectroelectrochemical titrations allow determination of the redox potentials of different heme groups for protein molecules immobilized on nanostructured silver electrodes, under conditions that mimic some features of the physiological membrane, such as: hydrophobic environment, restricted motion and defined directionality of electron transfer. Also, RR and SERR can reveal differences in terms of catalytic cycle, regulation of electron flow and proton translocation between the oxidases of different types.