A chemical discriminating method of myeloperoxidase, lactoperoxidase, saliva peroxidase and horseradish peroxidase.

As a chemically discriminating method of myeloperoxidase, lactoperoxidase, saliva peroxidase and horseradish peroxidase, the halide-required oxidation of fuchsin basic and acid red No. 106 mediated by the peroxidases in the presence of hydrogen peroxide were examined. Both fuchsin basic and acid red No. 106 were not directly oxidized by the peroxidase systems. Chloride and bromide ions mediated the reaction by the myeloperoxidase-hydrogen peroxide system, but fluoride ion did not. While bromide ion mediated the reactions by the lactoperoxidase and saliva peroxidase systems, fluoride and chloride ions did not and fluoride ion rather inhibited the bromide ion mediated oxidation. The horseradish peroxidase system had little effect on the dye oxidation even in the presence of fluoride, chloride or bromide ion.These results show that myeloperoxidase, lactoperoxidase, saliva peroxidase and horseradish peroxidase could be classified on the basis of the halide dependent oxidation into three types of (i) myeloperoxidase, (ii) lactoperoxidase and saliva peroxidase and (iii) horseradish peroxidase.