Myoglobin as An Efficient Electrocatalyst for Nitromethane Reduction

Document Type

Article

Publication Date

6-28-2004

Publication Title

Inorganic Chemistry

Abstract

Xenobiotic metabolizing heme enzymes are thought to take a crucial part in the activation of a variety of carcinogens, including nitro compounds, through catalytic electron-transfer reactions, especially under anaerobic conditions. Myoglobin (Mb), as a model heme enzyme, is found to act as an efficient electrocatalyst for the reduction of nitromethane in thin surfactant films on pyrolytic graphite electrodes. The electrocatalytic process is characterized by cyclic voltammetry. The Mb−FeII−nitrosomethane complex, a possible intermediate in the catalysis, is characterized spectroscopically in the surfactant film on indium tin oxide electrodes. Bulk electrolysis indicates the formation of mainly methylhydroxylamine as an end aqueous product. A rationale for the catalysis invokes the highly reduced FeI state of myoglobin in surfactant film; the latter engages in efficient inner-sphere electron transfers to the nitro compound coupled to proton transfers.

DOI

10.1021/ic035173e

Volume

43

Issue

13

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