Infrared magnetic circular dichroism of myoglobin derivatives.

摘要: Abstract By use of a newly constructed CD instrument, infared magnetic circular dichroism (MCD) spectra were observed for various myoglobin derivatives. The ferric high spin derivatives such as fluoride, water and hydroxide complexes, commonly exhibited the MCD consisting positive A terms. Therefore, results reinforced assignment that infrared band is charge transfer transition to degenerate excited state (eg (dπ)). Since fraction term estimated was ≈80% fluoride ≈35% water, effective symmetry determined be close D4h, while seems have lower components. low cyanide, imidazole azide showed which are very similar electronic absorption spectra. These assigned transitions from porphyrin π iron d orbitals on ground they only groups insensitive axial ligands. lack temperature dependence in magnitude indicated attributable Faraday B Deoxymyoglobin, ferrous derivative, had fairly strong around 760 nm with an anisotropy factor (Δe/e) 1.4·10−4. It shows some small bands 800 1800 nm. Among derivatives, carbonmonoxymyoglobin did not give any observable region oxymyoglobin seemed significant range 700 1000