Luminol chemiluminescence reaction catalyzed by a microbial peroxidase

A peroxidase produced by microorganisms belonging to the genera Arthromyces and Coprinus was found to be a potent catalyst for the chemiluminescent oxidation of luminol, the luminescence produced per unit of microbial peroxidase protein being well over 100 times as strong as that produced by horseradish peroxidase. No large difference in Km value for H2O2 in the presence of luminol was found between Arthromyces ramosus peroxidase and horseradish peroxidase (7.0 and 15.5 microM, respectively), but Vmax of the Arthromyces peroxidase was 500 times greater than that of the horseradish peroxidase. It was also found that the Arthromyces peroxidase surpasses, beyond expectation, the horseradish peroxidase in the initial velocity of the chemiluminescence reaction with the stopped-flow method. The Arthromyces peroxidase was used for the glucose and cholesterol assays, which were notably more sensitive than the corresponding assays involving the horseradish peroxidase.