1
|
Otsuka M, Marks SA, Winnica DE, Amoscato AA, Pearce LL, Peterson J. Covalent modifications of hemoglobin by nitrite anion: formation kinetics and properties of nitrihemoglobin. Chem Res Toxicol 2010; 23:1786-95. [PMID: 20961082 DOI: 10.1021/tx100242w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The green nitrihemoglobin (α(2)β(2) tetramer, NHb) was prepared by the aerobic reaction of excess nitrite with human hemoglobin A(0) under mildly acidic conditions. A rate equation was determined and found to depend on nitrite, hydrogen ion, and oxygen concentrations: -d[HbNO(2)]/dt = [k(1) + k(2)(K(a)[HNO(2)])[O(2)](1/2)][HbNO(2)], where k(1) = (2.4 ± 0.9) × 10(-4) s(-1), k(2) = (1 ± 0.2) × 10(5) M(-5/2) s(-1), and K(a) is the acid dissociation constant for nitrous acid (4.5 × 10(-4) M). Also, the chemical properties of NHb are compared to those of the normal hemoglobin (including the addition products of common oxidation states with exogenous ligands, the alkaline transitions of the ferric forms, and the oxygen binding characteristics of the ferrous forms) and were found to be nearly indistinguishable. Therefore, the replacement of a single vinyl hydrogen with a nitro group on the periphery of each macrocycle in hemoglobin does not significantly perturb the interaction between the hemes and the heme pockets. Because nonphotochemical reaction chemistry must necessarily be most dependent on electronic ground states, it follows that the clearly visible difference in color between hemoglobin A(0) and NHb must be associated primarily with the respective electronic excited states. The possibility of NHb formation in vivo and its likely consequences are considered.
Collapse
Affiliation(s)
- Mai Otsuka
- Department of Chemistry, Carnegie Mellon University, Mellon Institute, Pittsburgh, Pennsylvania 15213, USA
| | | | | | | | | | | |
Collapse
|
3
|
Cheesman MR, Ferguson SJ, Moir JW, Richardson DJ, Zumft WG, Thomson AJ. Two enzymes with a common function but different heme ligands in the forms as isolated. Optical and magnetic properties of the heme groups in the oxidized forms of nitrite reductase, cytochrome cd1, from Pseudomonas stutzeri and Thiosphaera pantotropha. Biochemistry 1997; 36:16267-76. [PMID: 9405061 DOI: 10.1021/bi971677a] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It is shown that, in the oxidized state, heme c of Pseudomonas stutzeri (ZoBell strain) cytochrome cd1 has histidine-methionine ligation as observed for cytochrome cd1 from Pseudomonas aeruginosa [Sutherland, J., Greenwood, C., Peterson, J., and Thomson, A. J. (1986) Biochem. J. 233, 893-898]. However, the X-ray structure of Thiosphaera pantotropha cytochrome cd1 reveals bis-histidine ligation for heme c. It is confirmed by EPR and near-infrared (NIR) MCD measurements that the bis-histidine coordination remains unaltered in the solution phase. Hence, the difference between the heme c ligation states defines two distinct classes of oxidized cytochromes cd1 as isolated. A weak feature in the T. pantotropha NIR MCD at 1900 nm suggests that a small population of heme c has histidine-methionine coordination. The ligation state of heme d1 cannot be defined with the same level of confidence, because the porphyrin-to-Fe(III) charge-transfer (CT) bands are less well characterized for this class of partially reduced porphyrin ring. However, variable temperature absorption and MCD spectra show that, in the T. pantotropha enzyme, heme d1 exists in a thermal low-spin/high-spin mixture with the low-spin as the ground state, whereas in P. stutzeri cytochrome cd1, and d1 heme is low-spin at all temperatures. A weak band, assigned as the heme d1 porphyrin-pi(a1u,a2u)-to-ferric(d) charge-transfer transition has been identified for the first time at 2170 nm. Its magnetic properties show the heme d1 to have an unusual (dxz,yz)4(dxy)1 electronic ground state as is found for low-spin Fe(III) chlorins [Cheesman, M. R., and Walker, F. A. (1996) J. Am. Chem. Soc. 118, 7373-7380]. It is proposed that the localization of the Fe(III) unpaired d-electron in an orbital lying in the heme plane may decrease the affinity of the Fe(III) heme for unsaturated ligands such as NO. Although heme d1 in the enzymes from P. stutzeri and T. pantotropha shows different temperature-dependent spin properties, the positions of the low-spin Fe(III) alpha-absorption band, at approximately 640 nm, are very similar to those observed for cytochromes cd1 from eight other sources, suggesting that all have similar strength fields from the axial ligands and, hence, that all have the same coordination, namely histidine-tyrosine or possibly histidine-hydroxide at the heme.
Collapse
Affiliation(s)
- M R Cheesman
- Centre for Metalloprotein Spectroscopy and Biology, School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ, U.K.
| | | | | | | | | | | |
Collapse
|
4
|
Walker FA, Nasri H, Turowska-Tyrk I, Mohanrao K, Watson CT, Shokhirev NV, Debrunner PG, Scheidt WR. π-Acid Ligands in Iron(III) Porphyrinates. Characterization of Low-Spin Bis(tert-butylisocyanide)(porphyrinato)iron(III) Complexes Having (dxz,dyz)4(dxy)1 Ground States. J Am Chem Soc 1996. [DOI: 10.1021/ja961971a] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- F. Ann Walker
- Contribution from the Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, and Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801
| | - Habib Nasri
- Contribution from the Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, and Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801
| | - Ilona Turowska-Tyrk
- Contribution from the Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, and Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801
| | - K. Mohanrao
- Contribution from the Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, and Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801
| | - C. Todd Watson
- Contribution from the Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, and Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801
| | - Nikolai V. Shokhirev
- Contribution from the Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, and Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801
| | - Peter G. Debrunner
- Contribution from the Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, and Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801
| | - W. Robert Scheidt
- Contribution from the Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, and Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801
| |
Collapse
|
5
|
Cheesman MR, Walker FA. Low-Temperature MCD Studies of Low-Spin Ferric Complexes of Tetramesitylporphyrinate: Evidence for the Novel (dxz,dyz)4(dxy)1 Ground State Which Models the Spectroscopic Properties of Heme d. J Am Chem Soc 1996. [DOI: 10.1021/ja960344i] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Myles R. Cheesman
- Contribution from the Centre for Metalloprotein Spectroscopy and Biology, School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ, Great Britain, and Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - F. Ann Walker
- Contribution from the Centre for Metalloprotein Spectroscopy and Biology, School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ, Great Britain, and Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| |
Collapse
|
6
|
Tsubaki M, Hori H, Mogi T, Anraku Y. Cyanide-binding site of bd-type ubiquinol oxidase from Escherichia coli. J Biol Chem 1995; 270:28565-9. [PMID: 7499371 DOI: 10.1074/jbc.270.48.28565] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We extended our investigation on the structure of the redox centers of bd-type ubiquinol oxidase from Escherichia coli using cyanide as a monitoring probe. We found that addition of cyanide to the air-oxidized O2-bound enzyme caused appearance of an infrared C-N stretching band at 2161 cm-1 and concomitant disappearance of the 647 nm absorption band of the cytochrome d (Fe2+)-O2 species. Addition of cyanide to the air-oxidized CO-bound enzyme also resulted in disappearance of the 635 nm absorption band and the 1983.4 cm-1 C-O infrared band of the cytochrome d (Fe2+)-CO species. The resulting species had a derivative-shaped electron paramagnetic resonance signal at g = 3.15. Upon partial reduction with sodium dithionite, this species was converted partly to a transient heme d (Fe3+)-C = N species having an electron paramagnetic resonance signal at gz = 2.96 and a C-N infrared band at 2138 cm-1. These observations suggest that the active site of the enzyme has a heme-heme binuclear metal center distinct from that of the heme-copper terminal oxidase and that the treatment of the air-oxidized enzyme with cyanide resulted in a cyanide-bridging species with "heme d(Fe3+)-C = N-heme b595(Fe3+)" structure.
Collapse
Affiliation(s)
- M Tsubaki
- Department of Life Science, Faculty of Science, Himeji Institute of Technology, Hyogo, Japan
| | | | | | | |
Collapse
|