Recently we showed that cytochrome c (cyt.c) has some cytochrome P450 (P450)-like substrate oxidation activity, which was enhanced by immobilization on poly-γ-methyl-L-glutamate. We now report that immobilized cyt.c catalysed hydroxylation of benzene when benzene containing a small amount of water was used as the reaction solvent, whereas free cyt.c did not catalyse the reaction. The EPR spectrum of immobilized cyt.c showed that the immobilization had caused a change in the protein conformation, and this might have led cyt.c to acquire the new activity. The results of the reaction using [ 18O]m-chloroperbenzoic acid (mCPBA) or [18O] molecular dioxygen showed that 59% of the oxygen atom of the product, phenol, was derived from the oxidant, and 33% from molecular dioxygen. When [18O]mCPBA was used as an oxidant, the value of deuterium isotope effect (kH/k D)was 1.08 when 18O was incorporated into the product, and 1.48 when 18O was not incorporated. These results indicate that immobilized cyt.c catalysed hydroxylation of benzene via two major pathways, of which one resembles that of P450.
|Number of pages||5|
|Journal||Journal of the Chemical Society, Perkin Transactions 1|
|Publication status||Published - 1994|
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