Abstract
The electron transport system coupled to the oxidation of methylamine in Pseudomonas AM1 was investigated by reconstituting it from the highly purified components. A mixture of methylamine dehydrogenase, cytochrome cH and cytochrome c oxidase (=cytochrome aa3) actively oxidized methylamine (161 mol of O2 consumed/mol of heme a of cytochrome c oxidase•min). In this system, addition of amicyanin did not affect the oxygen consumption rate. The oxygen consumption rate of the cell-free extract prepared from the cells cultivated in a copper-deficient medium was directly proportional to the amount of amicyanin added, and extrapolation to zero copper concentration gave a value of 28 mol of O2 consumed/mol of heme a of cytochrome c oxidase•min. These results suggest that methylamine oxidation in the bacterium can occur at least to some extent without participation of amicyanin.
