Oxidation of thiocyanate by peroxidases

Oxidation of Thiocyanate by Peroxidases

The pseudo-halide thiocyanate (SCN-) is a substrate for human heme peroxidases. These enzymes can be found in human blood leukocytes (myeloperoxidase, eosinophil peroxidase) as well as in body secretions like milk, saliva or tear fluid (lactoperoxidase). By two-electronic oxidation of SCN- to hypothiocyanite (-OSCN) these enzymes contribute to the humoral immune defense against pathogens. While in blood micromolar concentrations of SCN- can be found, depending e.g. on diet and smoking habits, in saliva the pseudo-halide is actively accumulated by secretory epthitelial cells which leads do millimolar concentrations.

By using 13C-NMR-spectroscopy and mass spectrometry we observed the formation of the interpseudohalogen species cyanogeniodide (ICN) upon co-incubation of lactoperoxidase or myeloperoxidase with SCN- and iodide (I-). In a follow-up study the strong bactericidal effect of ICN was shown. Based on these results we currently further explore both the biological activity of ICN as well as the formation of other interpseudohalogen species like cyanogen chloride or cyanogen bromide by human heme peroxidases.

Team Members

Dr. Jörg Flemmig, Denise Schlorke, Prof. Dr. Jürgen Arnhold


Prof. Esa-Matti Lilius
University of Turku
Turku, Finnland

Prof. Christine Winterbourn
University of Otago
Christchurch, New Zealand

letzte Änderung: 10.07.2017