Flavin-Dependent Dehydrogenases and Oxidases: Comparison of Structural Functional Properties (A Review)

Flavin-dependent dehydrogenases and oxidases are enzymes that play an important role in living organisms and are widely used in practice. Despite the different reactivity with respect to oxygen, the similarity of the structures of the active sites of a number of dehydrogenases and oxidases, up to the possibility of interconversion via the substitution of one amino acid, makes it possible to consider these classes as related. The vanillyl-alcohol oxidase family, one of the best-known families of oxidases, too, includes both classes of enzymes. However, in the literature, the relationship between oxidases and dehydrogenases is presented as a comparison of specific representatives of these classes or, more rarely, structural features of individual subclasses. In view of the aforesaid, consideration of the functional properties of oxidases beyond the context of their comparison with dehydrogenases seems to be incomplete. In addition, the search for and study of effectors, electron acceptors and inhibitors of oxidases and dehydrogenases, should be carried out taking account of the similarity of these classes, including the development of drugs that target these enzymes (for example, antitrypanosomal or antifungal drugs). This review analyzes the main structural differences between oxidases and dehydrogenases and considers the practical application of these classes, with particular attention to their role as drug targets.