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.
Chemical and Biotechnological R&D, Gedeon Richter Ltd, Budapest, Hungary. gy.keseru@richter.hu
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Keseru
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Balogh
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Karancsi
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