Resonance Raman investigations of heme proteins in the liquid, frozen and crystalline phase: A study of the heme pocket of myoglobin

Resonance Raman scattering is used to study myoglobin (Mb) in order to answer questions relevant to structure, dynamics and function of heme proteins.;Resonance Raman spectra of Mb single crystals are measured and compared to solution spectra for the first time. A low quantum yield laser light induced photoreduction of ferric Mb single crystals has been observed. A similar effect is present in certain mutant Mbs. Systematic variations of the depolarization ratios and the intensities of several Raman modes have been studied as a function of single crystal orientation.;Raman excitation profiles are measured for selected vibrational modes of metMB and MbCO. The Kramers-Kronig transform is utilized to construct the resonance Raman cross sections using the experimentally measured absorption cross section and extract the electron-nuclear coupling strengths.;Porphyrin normal modes sensitive to the heme core size and Fe oxidation state, are used in order to assign the oxidation, spin and coordination states of the heme iron atom in several mutated Mbs and specific Raman modes are used to identify their axial ligands.;Three Raman populations (A...