Methylamine dehydrogenase and cytochrome c552 from the bacterium W3A1

We describe a two-step purification of the methoxatin-containing enzyme methylamine dehydrogenase from crude extracts of the bacterium W3A1, and a longer purification of cytochrome c552 from the same organism. Some of the kinetic properties of the dehydrogenase are presented, together with the demonstration that c552 is an electron acceptor for this enzyme. Cytochrome c552 is the only hemeprotein we observed in the visible spectrum of intact W3A1 cells that were grown under the same culture conditions used for the protein purifications. Addition of methylamine to whole cells causes an increase in the rate of O2 uptake together with an abrupt reduction of c552. We propose that, in vivo, the electrons from the amine reach the hemeprotein through the dehydrogenase.