Amicyanin: An electron acceptor of methylamine dehydrogenase

A type I blue copper protein, “amicyanin”, was purified from a cell-free extract of methylamine-grown Pseudomonas AM1. It was found that amicyanin is able to serve as a primary electron acceptor of methylamine dehydrogenase. Amicyanin was reduced by the addition of both methylamine dehydrogenase and methylamine. Cytochromes c could not be directly reduced but could be reduced with the addition of amicyanin. The results strongly suggest that amicyanin participates as an electron carrier between methylamine dehydrogenase and cytochrome c in the electron transport chain of the methylamine-grown cell.