The 2-electron reduction of sperm whale ferryl myoglobin by ethanol

Upon the addition of hydrogen peroxide or ethyl hydroperoxide to sperm whale metmyoglobin (MbIII) in the presence of ethanol, MbIII was converted to oxymyoglobin (MbIIO2) under aerobic conditions and carboxymyoglobin (MbIICO) under CO-saturated conditions. MbIIO2 and MbIICO were also formed when ethanol was added to ferryl myoglobin (MbIV) which had been formed from the reaction of MbIII with hydrogen peroxide. From the stoichiometry, the primary reaction was formulated as follows. MbIV + ethanol----MbII + acetaldehyde The reaction was optimal at pH 7.0-7.5. Sperm whale ferryl myoglobin was reduced less effectively by methanol and n-butanol, but not at all by sec- and tert-butanols. The reduction of ferryl hemoproteins by ethanol was slower with horse heart myoglobin and was not observed with bovine hemoglobin or horseradish peroxidase.