[Effect of selected physico-chemical parameters on changes in ascorbate oxidase and ceruloplasmin activities]

The paper presents the results of kinetic studies covering the reactions with the participation of two enzymes belonging to the group of "blue oxidases"--ascorbate oxidase and ceruloplasmin. Using variable physico-chemical parameters of reactions such as: temperature, presence of denaturizing factors, various substrates, it was possible to draw conclusions as to the structure and mechanism of reactions catalyzed by these enzymes. The following findings were established: 1. Ceruloplasmin is characterized by the absence of quarternary structure and lesser substrate specificity as compared with ascorbate oxidase. 2. The mechanism of reactions catalyzed by ceruloplasmin and ascorbate oxidase is different, probably due to the fact that there is no typical active centre binding the substrate in ceruloplasmin. 3. The application of variable parameters of physico-chemical reactions in the kinetic studies facilitates the description of the structures of enzymes and the mechanism of reactions being catalyzed by them.