Reaction of cytochrome P450BM3 and peroxynitrite yields nitrosyl complex. Journal   Journal of the American Chemical Society. Citation   J Am Chem Soc. 129(18):5855-9 Publication date   2007 May 9 Authors   Behan RK Hoffart LM Stone KL Krebs C Green MT Investigators   Michael Green Carsten Krebs MeSH headings   Cytochrome P-450 Enzyme System Nitroso Compounds Peroxynitrous Acid MeSH qualifiers   chemistry Abstract   Peroxynitrite has come into the spotlight in recent years. Its effects on proteins have been implicated in several diseases such as acute lung injury, rheumatoid arthritis, implant rejection, artherosclerosis, Parkinson's disease, and Alzheimer's disease. Peroxynitrite is thought to inactivate a variety of proteins including thiolate-ligated heme proteins such as cytochrome P450 2B1 and PGI2 synthase, through the nitration of tyrosine residues. In previous studies it was reported that thiolate-ligated heme enzymes react with peroxynitrite to form a ferryl intermediate. In an effort to spectroscopically characterize this species in P450BM3, we discovered that the peroxynitrite-generated intermediate is not an FeIVoxo, but rather an iron-nitrosyl [FeNO]6 complex. We present density functional calculations as well as Mössbauer and stopped-flow spectroscopic characterizations of the peroxynitrite-generated intermediate in P450BM3.