The Biochemistry Of the Particulate Methane Monooxygenase

Summary

The particulate methane monooxygenase (pMMO) found in the intracytoplasmic membranes of methanotrophs has been known to be very difficult to study. Recent progress in our laboratory indicates that the pMMO is a novel copper-containing enzyme [1]. Metal/protein ratio data analysis clearly suggests that the pMMO is a multiple copper- containing enzyme. The pMMO-associated copper ions appear to be organized into trinuclear cluster units with rather defined-magnetic and redox properties. These copper clusters has been shown to be involved in dioxygen activation. The as-isolated pMMO enriched-membranes often contain a mixture of Cu(I) and Cu(II) ions in various proportions, depending on the history of the samples. The functional form of the enzyme has been found to be the reduced or partially reduced form.