CHARACTERIZATION OF PEROXIDASES IN LUMINOL CHEMILUMINESCENCE COUPLED WITH COPPER-CATALYZED OXIDATION OF CYSTEAMINE

Hydrogen peroxide formed during the course of the copper(II)-catalysed oxidation of cysteamine with oxygen was continuously determined by a peroxidase (POD)-catalysed luminol chemiluminescence (CL) method. Hors eradish peroxidase (HRP), lactoperoxidase (LPO) and Arthromyces ramosu s peroxidase (ARP) were used as a CL catalyst. The respective PODs gav e specific CL intensity-time profiles. HRP caused a CL delay. and ARP gave a time-response curve which followed the production rate of H2O2. LPO gave only a weak CL flash which decayed promptly. These differenc es of CL response curves could be explained in terms of the different reactivities of PODs for superoxide anion and the different formation rate of luminol radicals in the peroxidation of luminol catalysed by P OD.