Chemiluminescence assay for tetrahydrobiopterin based on the generation of hydrogen peroxide using isoluminol-microperoxidase in the presence of 1-methoxy PMS

We developed a novel highly sensitive chemiluminescence (CL) method for BH(4). The principle of the proposed method is based on active oxygen formation induced by 1-methoxy-5-methyl phenazinium methyl sulphate (1-methoxy PMS) in the presence of dissolved oxygen. Furthermore, active oxygen is determined by a CL assay involving the luminol reaction with microperoxidase. In this report, we examined the mechanism of formation and identified the Reactive Oxygen Species derived from BH(4) employing 1-methoxy PMS. Additionally, optimum conditions for the CL assay of BH(4) were established.