Phosphorylation coupled to nitrite and nitrate reductase in Micrococcus denitrificans

Abstract

During the enzymic reduction of ni­trite or nitrate in cell free extraets from anaerobically grown M. denitrificans, phosphorylation takes place, as judged by the incorporation of P12 into the organic fraction. Large amounts of ADP inhibit both phosphorylations as well as nitrite (but not nitrate) redactase; it follows that nitrite redactase acts tiglitly coupled to phosphorylation. The inhibitory action of ADP disappears by increasing the concentration of phosphate and this effect cannot be explained in terms of a single equilibrium.