MANGANESE MICROPEROXIDASE-8

Demetalation of Fe(III) microperoxidase-8 (MP8) by anhydrous HF gives metal-free MP8. a convenient starting material for a wide variety of m etal-substituted MP8 derivatives, including Mn(III)MP8. Mn(III)MP8 was produced by treatment of metal-free MP8 with manganous acetate in aer ated aqueous solution; it was characterized by mass spectrometry and U V-visible absorption spectroscopy. Resonance Raman spectra suggest tha t Mn(III)MP8 contains histidine and water axial ligands at neutral pH. The Mn(IV)=O derivative is readily prepared by oxidation of Mn(III))M P8 with hydrogen peroxide or Ru(bpy)3(3+) (bpy = 2,2'-bipyridine).