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Title: Nitric oxide adducts of the binuclear iron site of hemerythrin: spectroscopy and reactivity

Abstract

Nitric oxide forms adducts with the binuclear iron site of hemerythrin (Hr) at (Fe(II), Fe(II)) deoxy and (Fe(II), Fe(III))semimet oxidation levels. With deoxy Hr the results establish that (i) NO binds reversibly, forming a complex which the authors label deoxy HrNO, (ii) NO forms a similar but distinct complex in the presence of fluoride, which they label deoxy HrFNO, (iii) NO is directly coordinated to one iron atom of the binuclear pair in these adducts, most likely in a bent end-on fashion, and (iv) the iron atoms in the binuclear sites of both deoxyHrNO and deoxy HrFNA are antiferromagnetically coupled, thereby generating unique electron paramagnetic resonance (EPR) detectable species. The novel EPR signal of deoxyHrNO (deoxyHrFNO) is explained by the magnetic interaction of the Fe(II) and (FeNO)/sup 7/ centers observed by Moessbauer spectroscopy. The resonance Raman spectrum of deoxyHrNO shows features at 433 and 421 cm/sup -1/ that shift downward with /sup 15/N/sup 16/O and that are assigned to stretching and bending modes, respectively of the (FeNO)/sup 7/ unit. Sensitivity of the bending mode to D/sub 2/O suggests that bound NO participates in hydrogen bonding. They propose that the terminal oxygen atom of NO is hydrogen bonded to the protonmore » of the ..mu..-hydroxo bridge in the Fe-(OH)-Fe unit. Reversibility of NO binding to deoxyHr is demonstrated by bleaching of the optical and EPR spectra of deoxyHrNO upon additions of excess N/sub 3//sup -/ or CNA/sup -/. DeoxyHrNO undergoes autoxidation under anaerobic conditions over the course of several hours. The product of this autoxidation appears to be an EPR-silent NO adduct of semimetHr. The formal one-electron oxidations of the binuclear iron site of deoxyHr by No and by HNO/sub 2/ can conceivably occur with no net change in charge on the iron site.« less

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Iowa State Univ., Ames (USA)
OSTI Identifier:
5400783
Resource Type:
Journal Article
Journal Name:
Biochemistry; (United States)
Additional Journal Information:
Journal Volume: 27:3
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; 59 BASIC BIOLOGICAL SCIENCES; LABELLED COMPOUNDS; RAMAN SPECTRA; NITRIC OXIDE; ADDUCTS; PIGMENTS; ELECTRON SPIN RESONANCE; ERYTHROCYTES; HEAVY WATER; INVERTEBRATES; IRON COMPOUNDS; NITROGEN 15; OXIDATION; OXYGEN 16; ANIMALS; BIOLOGICAL MATERIALS; BLOOD; BLOOD CELLS; BODY FLUIDS; CHALCOGENIDES; CHEMICAL REACTIONS; EVEN-EVEN NUCLEI; HYDROGEN COMPOUNDS; ISOTOPES; LIGHT NUCLEI; MAGNETIC RESONANCE; MATERIALS; NITROGEN COMPOUNDS; NITROGEN ISOTOPES; NITROGEN OXIDES; NUCLEI; ODD-EVEN NUCLEI; OXIDES; OXYGEN COMPOUNDS; OXYGEN ISOTOPES; RESONANCE; SPECTRA; STABLE ISOTOPES; TRANSITION ELEMENT COMPOUNDS; WATER; 560300* - Chemicals Metabolism & Toxicology; 550201 - Biochemistry- Tracer Techniques

Citation Formats

Nocek, J M, Kurtz, Jr, D M, Sage, J T, Xia, Y M, Debrunner, P, Shiemke, A K, Sanders-Loehr, J, and Loehr, T M. Nitric oxide adducts of the binuclear iron site of hemerythrin: spectroscopy and reactivity. United States: N. p., 1988. Web. doi:10.1021/bi00403a026.
Nocek, J M, Kurtz, Jr, D M, Sage, J T, Xia, Y M, Debrunner, P, Shiemke, A K, Sanders-Loehr, J, & Loehr, T M. Nitric oxide adducts of the binuclear iron site of hemerythrin: spectroscopy and reactivity. United States. https://doi.org/10.1021/bi00403a026
Nocek, J M, Kurtz, Jr, D M, Sage, J T, Xia, Y M, Debrunner, P, Shiemke, A K, Sanders-Loehr, J, and Loehr, T M. Tue . "Nitric oxide adducts of the binuclear iron site of hemerythrin: spectroscopy and reactivity". United States. https://doi.org/10.1021/bi00403a026.
@article{osti_5400783,
title = {Nitric oxide adducts of the binuclear iron site of hemerythrin: spectroscopy and reactivity},
author = {Nocek, J M and Kurtz, Jr, D M and Sage, J T and Xia, Y M and Debrunner, P and Shiemke, A K and Sanders-Loehr, J and Loehr, T M},
abstractNote = {Nitric oxide forms adducts with the binuclear iron site of hemerythrin (Hr) at (Fe(II), Fe(II)) deoxy and (Fe(II), Fe(III))semimet oxidation levels. With deoxy Hr the results establish that (i) NO binds reversibly, forming a complex which the authors label deoxy HrNO, (ii) NO forms a similar but distinct complex in the presence of fluoride, which they label deoxy HrFNO, (iii) NO is directly coordinated to one iron atom of the binuclear pair in these adducts, most likely in a bent end-on fashion, and (iv) the iron atoms in the binuclear sites of both deoxyHrNO and deoxy HrFNA are antiferromagnetically coupled, thereby generating unique electron paramagnetic resonance (EPR) detectable species. The novel EPR signal of deoxyHrNO (deoxyHrFNO) is explained by the magnetic interaction of the Fe(II) and (FeNO)/sup 7/ centers observed by Moessbauer spectroscopy. The resonance Raman spectrum of deoxyHrNO shows features at 433 and 421 cm/sup -1/ that shift downward with /sup 15/N/sup 16/O and that are assigned to stretching and bending modes, respectively of the (FeNO)/sup 7/ unit. Sensitivity of the bending mode to D/sub 2/O suggests that bound NO participates in hydrogen bonding. They propose that the terminal oxygen atom of NO is hydrogen bonded to the proton of the ..mu..-hydroxo bridge in the Fe-(OH)-Fe unit. Reversibility of NO binding to deoxyHr is demonstrated by bleaching of the optical and EPR spectra of deoxyHrNO upon additions of excess N/sub 3//sup -/ or CNA/sup -/. DeoxyHrNO undergoes autoxidation under anaerobic conditions over the course of several hours. The product of this autoxidation appears to be an EPR-silent NO adduct of semimetHr. The formal one-electron oxidations of the binuclear iron site of deoxyHr by No and by HNO/sub 2/ can conceivably occur with no net change in charge on the iron site.},
doi = {10.1021/bi00403a026},
url = {https://www.osti.gov/biblio/5400783}, journal = {Biochemistry; (United States)},
number = ,
volume = 27:3,
place = {United States},
year = {1988},
month = {2}
}