Hydrogen Sulfide Oxidation by Myoglobin
Abstract only Enzymes in the sulfur network generate the signaling molecule, hydrogen sulfide (H 2 S), from amino acids cysteine and homocysteine. Since it is toxic at elevated concentrations, cells are equipped to clear H 2 S. A canonical sulfide oxidation pathway operates in mitochondria, converti...
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| Published in: | The FASEB journal Vol. 31; no. S1 |
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| Main Author: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
01-04-2017
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| Online Access: | Get full text |
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| Summary: | Abstract only
Enzymes in the sulfur network generate the signaling molecule, hydrogen sulfide (H
2
S), from amino acids cysteine and homocysteine. Since it is toxic at elevated concentrations, cells are equipped to clear H
2
S. A canonical sulfide oxidation pathway operates in mitochondria, converting H
2
S to thiosulfate and sulfate. We have recently discovered the ability of ferric hemoglobin to oxidize sulfide to thoisulfate and iron‐bound hydropolysulfides. In this study, we report that myoglobin exhibits a similar capacity for sulfide oxidation. We have trapped and characterized iron‐bound sulfur intermediates using cryo‐mass spectrometry and X‐ray absorption spectroscopy. Further support for the postulated intermediates in the chemically challenging conversion of H
2
S to thiosulfate and iron‐bound catenated sulfur products is provided by EPR and resonance Raman spectroscopy.
Support or Funding Information
This work was supported in part by grants from the National Institutes of Health (GM112455 to R.B. and DK068139 to T.L.S.) and the American Heart Association (14POST18760003 to P.K.Y.). We thank Dr. Markus Ruetz for help with the EPR studies, Andrew Hunt for help with the resonance Raman studies, and Dr. David Ballou for his assistance with the O
2
consumption assays. |
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| ISSN: | 0892-6638 1530-6860 |
| DOI: | 10.1096/fasebj.31.1_supplement.773.7 |