Iron hydroxide: model for enzymes that oxidize proteins.

The particles of an iron hydroxide sol were found to be a suitable model for protein-oxidizing enzymes such as peroxidase and polyphenol oxidase. In addition to small molecules such as pyrogallol, human serum proteins, albumin and gamma-globulin, are shown to be substrates of the oxidizing model. The activity is markedly increased by the addition of small amounts of copper to the iron in the particles of the sol. The size and molecular weight of the enzyme model, as well as the number of active centers were determined.