Mononuclear manganese redox enzymes

Mononuclear iron-sulfur clusters (continued) ferredoxins, 47 6-7 spin-lattice relaxation, 47 425-426 spin-spin interactions, 47 462, 465- 7 Mononuclear manganese redox enzymes, see Manganese, redox enzymes, mononuclear Mononuclear polysulfidemetal ring complexes, 31 97-99... 

Manganese redox enzymes exhibit a range of structural motifs involving mononuclear or bi- and tetranuclear aggregates of manganese ions. There has been a great deal of research in the area of structur-... 

Manganese superoxide dismutase (MnSOD) is a redox-active manganese enzyme that employs a mononuclear manganese ion at its active site. Discovered in 1970 (52), this enzyme catalyzes the dismuta-tion of superoxide (H02), to dioxygen and hydrogen peroxide, as shown in Scheme 2. Superoxide is the radical, one-electron-reduced... 

This process is catalyzed by a variety of catalase enzymes, the most common being the heme catalases, which accomplish the two-electron chemistry of Eq. (12) at a mononuclear heme center. Here, both the iron and its surrounding porphyrin ligand participate to the extent of one electron each in the redox process. Manganese catalases contain a binuclear Mn center and cycle between Mn2(II,II) and Mn2(III,III) oxidation states while carrying out the disproportionation of H2O2. The enzyme can... 

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