A small volume, self-contained, anaerobic circulating flow cell has been developed and applied to the resonance Raman investigation of two heme proteins: carboxyhemoglobin and cytochrome c. The cell has been demonstrated to be effective in reducing photodissociation of light-sensitive compounds. The flow performance is competitive with several alternative approaches. Electrochemical methods have been coupled with visible absorption and resonance Raman spectroscopy to titrate and determine potentiometrically the formal reduction potential of cytochrome c. Agreement between the results of visible and Raman spectral data demonstrates the feasibility of utilizing quantitative resonance Raman spectroscopy as a probe of formal reduction potentials of enzyme components.
Application of resonance Raman spectroscopy for interrogation of cryoradiolytically reduced oxygenated heme proteins
