| Abstract
| - Peroxynitrite has come into the spotlight in recent years. Its effects on proteins have beenimplicated 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 ofproteins including thiolate-ligated heme proteins such as cytochrome P450 2B1 and PGI2 synthase, throughthe nitration of tyrosine residues. In previous studies it was reported that thiolate-ligated heme enzymesreact with peroxynitrite to form a ferryl intermediate. In an effort to spectroscopically characterize this speciesin P450BM3, we discovered that the peroxynitrite-generated intermediate is not an FeIVoxo, but rather aniron−nitrosyl {FeNO}6 complex. We present density functional calculations as well as Mössbauer andstopped-flow spectroscopic characterizations of the peroxynitrite-generated intermediate in P450BM3.
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