Azurin is a redox partner for enzymes such as nitrite reductase or arsenite oxidase
Azurin is a bacterial blue copper-binding protein. It serves as a redox partner to enzymes such as nitrite reductase or arsenite oxidase. The copper of Azurin is tetrahedrally coordinated by a cysteine, 2 histidines, and a methionine residue. The electron transfer reactions are carried out with the Cu center transitioning between the oxidized Cu(II) form and the reduced Cu(I) form. Azurin can function as a tumor suppressor; it forms a complex with p53 that triggers apoptosis in various human cancer cells.