Peroxidase-Like Catalytic Activity of Aqueous- and Immobilized-Mn 3+ -octabromo-porphyrins on Ion-Exchange Resin Supplied as Mimetic of Horseradish Peroxidase

In order to explore the capability of metal porphyrins as an alternative of horseradish peroxidase (HRP), HRP-like activi-ty of three manganese-porphyrins (Mn-Ps) and three Mn-octabromo-porphyrins (Mn-OBPs) was examined in both aqueous and immobilized states. It was found that Mn3+-octabromotetrakis(1-methyl-pyridinium-4yl)porphine (Mn-OBTMPyP) has an activity of at least 90% of HRP in an aqueous solution. Mn-OBTMPyP exhibited a catalytic activity even in the presence of hydrogen peroxide without suicide reaction. In addition, Mn-OBTMPyP was revealed to function as an alternative to HRP in the quantitative determination of serum uric acid. These results are of great interest because they indicate that metal-octabromo-porphyrins possibly include promising candidates of artificial enzyme capable of substituting for HRP.