Electrostatic and conformational effects on the electronic structures of distortional isomers of a mixed-valence binuclear Cu complex.

The electronic structure of the binuclear copper complex [Cu(2)(L)](3+) [L = N(CH(2)CH(2)N(H)CH(2)CH(2)N(H)CH(2)CH(2))(3)N] has been investigated by resonance Raman and electroabsorption spectroscopy. Crystallographic Cu(2) distances of 2.364(1) and 2.

Q-Band resonance Raman investigation of turnip cytochrome f and Rhodobacter capsulatus cytochrome c1.

The results of a comprehensive Q-band resonance Raman investigation of cytochrome c1 and cytochrome f subunits of bc1 and b6f complexes are presented. Q-band excitation provides a particularly effective probe of the local heme environments of these species. The effects of protein conformation (particularly axial ligation) on heme structure and function were further investigated by comparison of spectra obtained from native subunits to those of a site directed c1 mutant (M183L) and various pH-dependent species of horse heart cytochrome c.

Q-band resonance Raman spectra of oxidized and reduced mitochondrial bc1 complexes.

Recently published crystallographic studies of mitochondrial bc1 complexes have stimulated renewed interest in the active site architecture of these important integral membrane proteins. We present resonance Raman spectra obtained via variable excitation within the heme Q-band from samples poised in several different net redox states. Appropriate subtraction and polarization analysis allows the vibrational behavior of the individual heme bL,bH, and c1 sites to be assessed.

Isolation and characterization of vibrational spectra of individual heme active sites in cytochrome bc1 complexes from Rhodobacter capsulatus.

Resonance Raman spectra of bc1 complexes and isolated c1 subunit from Rhodobacter capsulatus have been obtained using a variety of excitation wavelengths. Spectra obtained via Q-band excitation of bc1 complexes in different redox states were separated to yield the individual vibrational spectra of each of the three heme active sites. Hemes bH and c1 exhibit vibrational spectra typical of b- and c-type hemes, respectively.