Metalloporphyrin catalyzed oxidation of N-hydroxyguanidines: a biomimetic model for the H2O2-dependent activity of nitric oxide synthase.
A chemical model for the H2O2 promoted oxidation by nitric oxide synthase (NOS) has been developed. Biomimetic oxidations were carried out using H2O2 and tetrakis(perfluorophenyl)porphyrinato-iron(III) chloride (FeTPPF20) as a catalyst. Similarly to NOS our model system produces Ndelta-cyanoornithine, citrulline and NO from NOHA and did not oxidize arginine itself. Based on these results we propose a peroxide shunt to be involved in the catalytic cycle of NOS. To the best of our knowledge this is the first chemical system that semiquantitatively mimics NOS activity.
Keseru
G M
GM
Chemical and Biotechnological R&D, Gedeon Richter Ltd, Budapest, Hungary. gy.keseru@richter.hu
Balogh
G T
GT
Karancsi
T
T
D002384:Catalysis; D006146:Guanidines / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006898:Hydroxylamines; D008665:Metalloporphyrins / Q000737:chemistry*; D008956:Models, Chemical; D018716:Molecular Mimicry; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010084:Oxidation-Reduction
D006146:Guanidines; D006898:Hydroxylamines; D008665:Metalloporphyrins; C029604:hydroxyguanidine; D006861:Hydrogen Peroxide; D019001:Nitric Oxide Synthase