Spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (FeBMbs): relevance to denitrifying NO reductase†
Denitrifying NO reductases are evolutionarily related to the superfamily of heme-copper terminal oxidases. These transmembrane protein complexes utilize a heme-nonheme diiron center to reduce two NO molecules to N2O. To understand this reaction, the diiron site has been modeled using sperm whale myo...
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ftpubmed:oai:pubmedcentral.nih.gov:3125442 2023-05-15T18:26:50+02:00 Spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (FeBMbs): relevance to denitrifying NO reductase† Hayashi, Takahiro Miner, Kyle D. Yeung, Natasha Lin, Ying-Wu Lu, Yi Moënne-Loccoz, Pierre 2011-06-14 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3125442 http://www.ncbi.nlm.nih.gov/pubmed/21634416 https://doi.org/10.1021/bi200409a en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3125442 http://www.ncbi.nlm.nih.gov/pubmed/21634416 http://dx.doi.org/10.1021/bi200409a Article Text 2011 ftpubmed https://doi.org/10.1021/bi200409a 2013-09-03T16:39:22Z Denitrifying NO reductases are evolutionarily related to the superfamily of heme-copper terminal oxidases. These transmembrane protein complexes utilize a heme-nonheme diiron center to reduce two NO molecules to N2O. To understand this reaction, the diiron site has been modeled using sperm whale myoglobin as a scaffold and mutating distal residues Leu-29 and Phe-43 to histidines, and Val-68 to a glutamic acid to create a nonheme FeB site. The impact of incorporation of metal ions at this engineered site on the reaction of the ferrous heme with one NO was examined by UV-vis absorption, EPR, resonance Raman, and FTIR spectroscopies. UV-vis absorption and resonance Raman spectra demonstrate that the first NO molecule binds to the ferrous heme, but while the apoproteins and CuI- or ZnII-loaded proteins show characteristic EPR signatures of S = 1/2 six-coordinate heme {FeNO}7 species observable at liquid nitrogen temperature, the FeII-loaded proteins are EPR silent at ≥ 30 K. Vibrational modes from the heme [Fe-N-O] unit are identified in the RR and FTIR spectra using 15NO and 15N18O. The apo- and CuI-bound proteins exhibit ν(FeNO) and ν(NO) that are only marginally distinct from those reported for native myoglobin. However, binding of FeII at the FeB site shifts the heme ν(FeNO) by +17 cm-1 and the ν(NO) by -50 cm-1 to 1549 cm-1. This low ν(NO) is without precedent for a six-coordinate heme {FeNO}7 species and suggests that the NO group adopts a strong nitroxyl character stabilized by electrostatic interaction with the nearby nonheme FeII. Detection of a similarly low ν(NO) in the ZnII-loaded protein supports this interpretation. Text Sperm whale PubMed Central (PMC) Biochemistry 50 26 5939 5947 |
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Article Hayashi, Takahiro Miner, Kyle D. Yeung, Natasha Lin, Ying-Wu Lu, Yi Moënne-Loccoz, Pierre Spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (FeBMbs): relevance to denitrifying NO reductase† |
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Denitrifying NO reductases are evolutionarily related to the superfamily of heme-copper terminal oxidases. These transmembrane protein complexes utilize a heme-nonheme diiron center to reduce two NO molecules to N2O. To understand this reaction, the diiron site has been modeled using sperm whale myoglobin as a scaffold and mutating distal residues Leu-29 and Phe-43 to histidines, and Val-68 to a glutamic acid to create a nonheme FeB site. The impact of incorporation of metal ions at this engineered site on the reaction of the ferrous heme with one NO was examined by UV-vis absorption, EPR, resonance Raman, and FTIR spectroscopies. UV-vis absorption and resonance Raman spectra demonstrate that the first NO molecule binds to the ferrous heme, but while the apoproteins and CuI- or ZnII-loaded proteins show characteristic EPR signatures of S = 1/2 six-coordinate heme {FeNO}7 species observable at liquid nitrogen temperature, the FeII-loaded proteins are EPR silent at ≥ 30 K. Vibrational modes from the heme [Fe-N-O] unit are identified in the RR and FTIR spectra using 15NO and 15N18O. The apo- and CuI-bound proteins exhibit ν(FeNO) and ν(NO) that are only marginally distinct from those reported for native myoglobin. However, binding of FeII at the FeB site shifts the heme ν(FeNO) by +17 cm-1 and the ν(NO) by -50 cm-1 to 1549 cm-1. This low ν(NO) is without precedent for a six-coordinate heme {FeNO}7 species and suggests that the NO group adopts a strong nitroxyl character stabilized by electrostatic interaction with the nearby nonheme FeII. Detection of a similarly low ν(NO) in the ZnII-loaded protein supports this interpretation. |
format |
Text |
author |
Hayashi, Takahiro Miner, Kyle D. Yeung, Natasha Lin, Ying-Wu Lu, Yi Moënne-Loccoz, Pierre |
author_facet |
Hayashi, Takahiro Miner, Kyle D. Yeung, Natasha Lin, Ying-Wu Lu, Yi Moënne-Loccoz, Pierre |
author_sort |
Hayashi, Takahiro |
title |
Spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (FeBMbs): relevance to denitrifying NO reductase† |
title_short |
Spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (FeBMbs): relevance to denitrifying NO reductase† |
title_full |
Spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (FeBMbs): relevance to denitrifying NO reductase† |
title_fullStr |
Spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (FeBMbs): relevance to denitrifying NO reductase† |
title_full_unstemmed |
Spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (FeBMbs): relevance to denitrifying NO reductase† |
title_sort |
spectroscopic characterization of mononitrosyl complexes in heme-nonheme diiron centers within the myoglobin scaffold (febmbs): relevance to denitrifying no reductase† |
publishDate |
2011 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3125442 http://www.ncbi.nlm.nih.gov/pubmed/21634416 https://doi.org/10.1021/bi200409a |
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Sperm whale |
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Sperm whale |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3125442 http://www.ncbi.nlm.nih.gov/pubmed/21634416 http://dx.doi.org/10.1021/bi200409a |
op_doi |
https://doi.org/10.1021/bi200409a |
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Biochemistry |
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50 |
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26 |
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5939 |
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5947 |
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