Kinetics of interconversion of redox intermediates of lactoperoxidase, eosinophil peroxidase and myeloperoxidase.

Myeloperoxidase, eosinophil peroxidase and lactoperoxidase are heme-containing oxidoreductases, which undergo a series of redox reactions. Though sharing functional and structural homology, reflecting their phylogenetic origin, differences are observed regarding their spectral features, substrate specificities, redox properties and kinetics of interconversion of the relevant redox intermediates ferric and ferrous peroxidase, compound I, compound II and compound III. Depending on substrate availability, these heme enzymes path through the halogenation cycle and/or the peroxidase cycle and/or act as poor (pseudo-) catalases.