Resonance Raman spectra and biological significance of high-valent iron (Ⅳ, Ⅴ) porphyrins

摘要

Extensive research in the past decades has shown that nature relies on high-valent iron (Ⅳ,Ⅴ) porphyrins in a number of enzyme-directed processes of heme proteins. For example, hydroxylation reaction catalyzed by cytochrome P450 involves an iron porphyrin intermediate which contains the oxoferryl moiety (Fe(Ⅳ)=O). Liver microsomal cytochrome P450-LM 3,4 is known to catalyze the transfer of a functionalized nitrogen atom intra-as well as inter-molecularly, and the proposed raction cycle presumably involves a high-valent iron porphyrin intermediate which contains the nitrido-iron moiety (Fe(Ⅴ)≡N). This review is focused on the biological significance of these high-valent iron (Ⅳ,Ⅴ) porphyrins and their Fe(Ⅳ)=O and Fe(Ⅴ)=N stretching vibrations observed in resonance Raman spectra.