1
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Gardner AM, Gardner PR. Dioxygen and glucose force motion of the electron-transfer switch in the iron(III) flavohemoglobin-type nitric oxide dioxygenase. J Inorg Biochem 2023; 245:112257. [PMID: 37229820 DOI: 10.1016/j.jinorgbio.2023.112257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 04/28/2023] [Accepted: 05/11/2023] [Indexed: 05/27/2023]
Abstract
Kinetic and structural investigations of the flavohemoglobin-type NO dioxygenase have suggested critical roles for transient Fe(III)O2 complex formation and O2-forced movements affecting hydride transfer to the FAD cofactor and electron-transfer to the Fe(III)O2 complex. Stark-effect theory together with structural models and dipole and internal electrostatic field determinations provided a semi-quantitative spectroscopic method for investigating the proposed Fe(III)O2 complex and O2-forced movements. Deoxygenation of the enzyme causes Stark effects on the ferric heme Soret and charge-transfer bands revealing the Fe(III)O2 complex. Deoxygenation also elicits Stark effects on the FAD that expose forces and motions that create a more restricted NADH access to FAD for hydride transfer and switch electron-transfer off. Glucose also forces the enzyme toward an off state. Amino acid substitutions at the B10, E7, E11, G8, D5, and F7 positions influence the Stark effects of O2 on resting heme spin states and FAD consistent with the proposed roles of the side chains in the enzyme mechanism. Deoxygenation of ferric myoglobin and hemoglobin A also induces Stark effects on the hemes suggesting a common 'oxy-met' state. The ferric myoglobin and hemoglobin heme spectra are also glucose-responsive. A conserved glucose or glucose-6-phosphate binding site is found bridging the BC-corner and G-helix in flavohemoglobin and myoglobin suggesting novel allosteric effector roles for glucose or glucose-6-phosphate in the NO dioxygenase and O2 storage functions. The results support the proposed roles of a ferric O2 intermediate and protein motions in regulating electron-transfer during NO dioxygenase turnover.
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Affiliation(s)
- Anne M Gardner
- Research and Development Division, Miami Valley Biotech, Suite 2445, 1001 E. 2(nd) Street, Dayton, OH 45402, USA; Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center, R033, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
| | - Paul R Gardner
- Research and Development Division, Miami Valley Biotech, Suite 2445, 1001 E. 2(nd) Street, Dayton, OH 45402, USA; Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center, R033, 3333 Burnet Avenue, Cincinnati, OH 45229, USA; Chemistry and Biochemistry Department, University of Dayton, 300 College Park, Dayton, OH 45469, USA.
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2
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Butcher D, Bernad S, Derrien V, Sebban P, Miksovska J. Role of Ionic Strength and pH in Modulating Thermodynamic Profiles Associated with CO Escape from Rice Nonsymbiotic Hemoglobin 1. J Phys Chem B 2017; 121:351-364. [PMID: 28072536 DOI: 10.1021/acs.jpcb.6b06933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Type 1 nonsymbiotic hemoglobins are found in a wide variety of land plants and exhibit very high affinities for exogenous gaseous ligands. These proteins are presumed to have a role in protecting plant cells from oxidative stress under etiolated/hypoxic conditions through NO dioxygenase activity. In this study we have employed photoacoustic calorimetry, time-resolved absorption spectroscopy, and classical molecular dynamics simulations in order to elucidate thermodynamics, kinetics, and ligand migration pathways upon CO photodissociation from WT and a H73L mutant of type 1 nonsymbiotic hemoglobin from Oryza sativa (rice). We observe a temperature dependence of the resolved thermodynamic parameters for CO photodissociation from CO-rHb1 which we attribute to temperature dependent formation of a network of electrostatic interactions in the vicinity of the heme propionate groups. We also observe slower ligand escape from the protein matrix under mildly acidic conditions in both the WT and H73L mutant (τ = 134 ± 19 and 90 ± 15 ns). Visualization of transient hydrophobic channels within our classical molecular dynamics trajectories allows us to attribute this phenomenon to a change in the ligand migration pathway which occurs upon protonation of the distal His73, His117, and His152. Protonation of these residues may be relevant to the functioning of the protein in vivo given that etiolation/hypoxia can cause a decrease in intracellular pH in plant cells.
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Affiliation(s)
- David Butcher
- Department of Chemistry and Biochemistry, Florida International University , Miami Florida 33199, United States
| | - Sophie Bernad
- Laboratoire de Chimie Physique, Université Paris-Sud 11 , 91405 Orsay, France
| | - Valerie Derrien
- Laboratoire de Chimie Physique, Université Paris-Sud 11 , 91405 Orsay, France
| | - Pierre Sebban
- Laboratoire de Chimie Physique, Université Paris-Sud 11 , 91405 Orsay, France
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University , Miami Florida 33199, United States.,Biomolecular Sciences Institute, Florida International University , Miami, Florida 33199, United States
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3
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Akbas N, Draganova EB, Block DR, Sook BR, Chan YF, Zhuo J, Eichenbaum Z, Rodgers KR, Dixon DW. Heme-bound SiaA from Streptococcus pyogenes: Effects of mutations and oxidation state on protein stability. J Inorg Biochem 2016; 158:99-109. [PMID: 26746808 PMCID: PMC4943329 DOI: 10.1016/j.jinorgbio.2015.10.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 10/01/2015] [Accepted: 10/28/2015] [Indexed: 11/30/2022]
Abstract
The protein SiaA (HtsA) is part of a heme uptake pathway in Streptococcus pyogenes. In this report, we present the heme binding of the alanine mutants of the axial histidine (H229A) and methionine (M79A) ligands, as well as a lysine (K61A) and cysteine (C58A) located near the heme propionates (based on homology modeling) and a control mutant (C47A). pH titrations gave pKa values ranging from 9.0 to 9.5, close to the value of 9.7 for WT SiaA. Resonance Raman spectra of the mutants suggested that the ferric heme environment may be distinct from the wild-type; spectra of the ferrous states were similar. The midpoint reduction potential of the K61A mutant was determined by spectroelectrochemical titration to be 61±3mV vs. SHE, similar to the wild-type protein (68±3mV). The addition of guanidine hydrochloride showed two processes for protein denaturation, consistent with heme loss from protein forms differing by the orientation of the heme in the binding pocket (the half-life for the slower process ranged from less than half a day to two days). The ease of protein unfolding was related to the strength of interaction of the residues with the heme. We hypothesize that kinetically facile but only partial unfolding, followed by a very slow approach to the completely unfolded state, may be a fundamental attribute of heme trafficking proteins. Small motions to release/transfer the heme accompanied by resistance to extensive unfolding may preserve the three dimensional form of the protein for further uptake and release.
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Affiliation(s)
- Neval Akbas
- Department of Chemistry, Georgia State University, Atlanta, GA 30302-3965, USA
| | | | - Darci R Block
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Brian R Sook
- Department of Chemistry, Georgia State University, Atlanta, GA 30302-3965, USA
| | - Yau Fong Chan
- Department of Chemistry, Georgia State University, Atlanta, GA 30302-3965, USA
| | - Joy Zhuo
- Department of Chemistry, Georgia State University, Atlanta, GA 30302-3965, USA
| | - Zehava Eichenbaum
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA
| | - Kenton R Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Dabney W Dixon
- Department of Chemistry, Georgia State University, Atlanta, GA 30302-3965, USA.
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4
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Johnson EA, Rice S, Preimesberger MR, Nye DB, Gilevicius L, Wenke BB, Brown JM, Witman GB, Lecomte JTJ. Characterization of THB1, a Chlamydomonas reinhardtii truncated hemoglobin: linkage to nitrogen metabolism and identification of lysine as the distal heme ligand. Biochemistry 2014; 53:4573-89. [PMID: 24964018 PMCID: PMC4108185 DOI: 10.1021/bi5005206] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/23/2014] [Indexed: 12/21/2022]
Abstract
The nuclear genome of the model organism Chlamydomonas reinhardtii contains genes for a dozen hemoglobins of the truncated lineage. Of those, THB1 is known to be expressed, but the product and its function have not yet been characterized. We present mutagenesis, optical, and nuclear magnetic resonance data for the recombinant protein and show that at pH near neutral in the absence of added ligand, THB1 coordinates the heme iron with the canonical proximal histidine and a distal lysine. In the cyanomet state, THB1 is structurally similar to other known truncated hemoglobins, particularly the heme domain of Chlamydomonas eugametos LI637, a light-induced chloroplastic hemoglobin. Recombinant THB1 is capable of binding nitric oxide (NO(•)) in either the ferric or ferrous state and has efficient NO(•) dioxygenase activity. By using different C. reinhardtii strains and growth conditions, we demonstrate that the expression of THB1 is under the control of the NIT2 regulatory gene and that the hemoglobin is linked to the nitrogen assimilation pathway.
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Affiliation(s)
- Eric A. Johnson
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Selena
L. Rice
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | | | - Dillon B. Nye
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Lukas Gilevicius
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Belinda B. Wenke
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Jason M. Brown
- Department
of Cell and Developmental Biology, University
of Massachusetts Medical School, Worcester, Massachusetts 01655, United States
| | - George B. Witman
- Department
of Cell and Developmental Biology, University
of Massachusetts Medical School, Worcester, Massachusetts 01655, United States
| | - Juliette T. J. Lecomte
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
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5
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Gheidi M, Safari N, Zahedi M. Chameleonic Nature of Hydroxyheme in Heme Oxygenase and Its Reactivity: A Density Functional Theory Study. Inorg Chem 2014; 53:2766-75. [DOI: 10.1021/ic402754y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Mahin Gheidi
- Department of Chemistry, Faculty
of Sciences, Shahid Beheshti University, G. C. Evin, 19839-63113 Tehran, Iran
| | - Nasser Safari
- Department of Chemistry, Faculty
of Sciences, Shahid Beheshti University, G. C. Evin, 19839-63113 Tehran, Iran
| | - Mansour Zahedi
- Department of Chemistry, Faculty
of Sciences, Shahid Beheshti University, G. C. Evin, 19839-63113 Tehran, Iran
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6
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Moreira LM, Poli AL, Lyon JP, Aimbire F, Toledo JC, Costa-Filho AJ, Imasato H. Ligand changes in ferric species of the giant extracellular hemoglobin of Glossoscolex paulistusas function of pH: correlations between redox, spectroscopic and oligomeric properties and general implications with different hemoproteins. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s108842461000201x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present review is focused on the relationship between oligomeric and heme properties of HbGp, emphasizing the characteristics that can be generalized to other hemoproteins. This study represents the state-of-the-art with respect to the approaches for investigating giant extracellular hemoglobins as well as the correlation between oligomeric assembly alterations and their consequent changes in the first coordination sphere. A wide introduction focused on the properties of this hemoglobin is developed. Indeed, this hemoprotein is considered an interesting prototype of blood substitute and biosensor due to its peculiar properties, such as resistance to autoxidation and oligomeric stability. Previous studies by our group employing UV-vis, EPR and CD spectroscopies have been revised in a complete approach, in agreement with recent and relevant data from the literature. In fact, a consistent and inter-related spectroscopic study is described propitiating a wide assignment of "fingerprint" peaks found in the techniques evaluated in this paper. This review furnishes physicochemical information regarding the identification of ferric heme species of hemoproteins and metallic complexes through their spectroscopic bands. This effort at the attribution of UV-vis, EPR and CD peaks is not restricted to HbGp, and includes a comparative analysis of several hemoproteins involving relevant implications regarding several types of iron-porphyrin systems.
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Affiliation(s)
- Leonardo Marmo Moreira
- Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, 12244-000 São José dos Campos SP, Brazil
- Instituto de Química de São Carlos, Universidade de São Paulo, 13560-970 São Carlos SP, Brazil
- Instituto de Pesquisa e Qualidade Acadêmica (IPQA), Universidade Camilo Castelo Branco, São José dos Campos SP, Brazil
| | - Alessandra Lima Poli
- Instituto de Química de São Carlos, Universidade de São Paulo, 13560-970 São Carlos SP, Brazil
| | - Juliana Pereira Lyon
- Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, 12244-000 São José dos Campos SP, Brazil
| | - Flávio Aimbire
- Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, 12244-000 São José dos Campos SP, Brazil
- Instituto de Pesquisa e Qualidade Acadêmica (IPQA), Universidade Camilo Castelo Branco, São José dos Campos SP, Brazil
| | | | | | - Hidetake Imasato
- Instituto de Química de São Carlos, Universidade de São Paulo, 13560-970 São Carlos SP, Brazil
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7
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Sen D, Poon LCH. RNA and DNA complexes with hemin [Fe(III) heme] are efficient peroxidases and peroxygenases: how do they do it and what does it mean? Crit Rev Biochem Mol Biol 2011; 46:478-92. [PMID: 21958168 DOI: 10.3109/10409238.2011.618220] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Guanine-rich RNAs and DNAs from chromosomal telomeres and elsewhere that fold into guanine quadruplexes (G-quadruplexes), are found to complex tightly with porphyrins such as N-methylmesoporphyrin IX (NMM) and hemin [Fe(III) heme]. By themselves, these DNAs and RNAs are found to be efficient catalysts for porphyrin metallation. When complexed with hemin, under physiological conditions, these nucleic acids display robust peroxidase (one-electron oxidation), as well as peroxygenase (two-electron oxidation, or oxygen transfer) activity. These surprising catalytic properties, that frequently match the catalytic performance of natural peroxidase and P450 monooxygenase enzymes, have been the subject of significant mechanistic analysis, as well as having found utility in a wide range of biosensing and other applications. This review summarizes recent insights into a surprising yet fundamental property of many RNAs and DNAs, a property with undoubted ramifications for cellular oxidative disease, de novo hemoenzyme design, and our understanding of the evolution of early biocatalytic systems.
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Affiliation(s)
- Dipankar Sen
- Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.
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8
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Toccafondi C, Prato M, Maidecchi G, Penco A, Bisio F, Cavalleri O, Canepa M. Optical properties of Yeast Cytochrome c monolayer on gold: an in situ spectroscopic ellipsometry investigation. J Colloid Interface Sci 2011; 364:125-32. [PMID: 21920531 DOI: 10.1016/j.jcis.2011.07.097] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/29/2011] [Accepted: 07/30/2011] [Indexed: 11/18/2022]
Abstract
The adsorption of Yeast Cytochrome c (YCC) on well defined, flat gold substrates has been studied by Spectroscopic Ellipsometry (SE) in the 245-1000 nm wavelength range. The investigation has been performed in aqueous ambient at room temperature, focusing on monolayer-thick films. In situ δΨ and δΔ difference spectra have shown reproducibly well-defined features related to molecular optical absorptions typical of the so-called heme group. The data have been reproduced quantitatively by a simple isotropic optical model, accounting for the molecular absorption spectrum and film-substrate interface effects. The simulations allowed a reliable estimate of the film thickness and the determination of the position and the shape of the so-called Soret absorption peak that, within the experimental uncertainty, is the same found for molecules in liquid. These findings suggest that YCC preserves its native structure upon adsorption. The same optical model was able to reproduce also ex situ results on rinsed and dried samples, dominated by the spectral features associated to the polypeptide chain that tend to overwhelm the heme absorption features.
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Affiliation(s)
- Chiara Toccafondi
- CNISM and Dipartimento di Fisica, Universitá di Genova, Via Dodecaneso 33, 16146 Genova, Italy
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9
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Wyer JA, Nielsen SB. Absorption in the Q-band region by isolated ferric heme+ and heme+(histidine) in vacuo. J Chem Phys 2010; 133:084306. [DOI: 10.1063/1.3474998] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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10
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Lykkegaard MK, Ehlerding A, Hvelplund P, Kadhane U, Kirketerp MBS, Nielsen SB, Panja S, Wyer JA, Zettergren H. A Soret Marker Band for Four-Coordinate Ferric Heme Proteins from Absorption Spectra of Isolated Fe(III)-Heme+ and Fe(III)-Heme+(His) Ions in Vacuo. J Am Chem Soc 2008; 130:11856-7. [DOI: 10.1021/ja803460c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Morten Køcks Lykkegaard
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Anneli Ehlerding
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Preben Hvelplund
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Umesh Kadhane
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Maj-Britt Suhr Kirketerp
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Steen Brøndsted Nielsen
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Subhasis Panja
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Jean Ann Wyer
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
| | - Henning Zettergren
- Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
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11
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Cowley AB, Benson DR. Weak-field anions displace the histidine ligand in a synthetic heme peptide but not in N-acetylmicroperoxidase-8: possible role of heme geometry differences. Inorg Chem 2007; 46:48-59. [PMID: 17198412 DOI: 10.1021/ic060682c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have recently reported that aquo and thioether complexes of the ferric cytochrome c heme peptide N-acetylmicroperoxidase-8 (FeIII-1) exhibit greater low-spin character than do the corresponding complexes of a synthetic, water-soluble, monohistidine-ligated heme peptide (FeIII-2; Cowley, A. B.; Lukat-Rodgers, G. S.; Rodgers, K. R.; Benson, D. R. Biochemistry 2004, 43, 1656-1666). Herein we report results of studies showing that weak-field ligands bearing a full (fluoride, chloride, hydroxide) or partial (phenoxide, thiocyanate) negative charge on the coordinating atom trigger dissociation of the axial His ligand in FeIII-2 but not in FeIII-1. We attribute the greater sensitivity of His ligation in FeIII-1 to weak-field anionic ligands than to weak-field neutral ligands to the following phenomena: (1) anionic ligands pull FeIII further from the mean plane of a porphyrin than do neutral ligands, which will have the effect of straining the His-Fe bond in FeIII-2, and (2) heme in FeIII-2 is likely to undergo a modest doming distortion following anion binding that will render the His-ligated side of the porphyrin concave, thereby increasing porphyrin/ligand steric interactions. We propose that ruffling of the heme in FeIII-1 is an important factor contributing to its ability to resist His dissociation by weak-field anions. First, ruffling should allow His to more closely approach the porphyrin than is possible in FeIII-2, thereby reducing bond strain following anion binding. Second, the ruffling deformation in FeIII-1, which is enforced by the double covalent heme-peptide linkage, will almost certainly prevent significant porphyrin doming.
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Affiliation(s)
- Aaron B Cowley
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
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12
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Copeland DM, West AH, Richter-Addo GB. Crystal structures of ferrous horse heart myoglobin complexed with nitric oxide and nitrosoethane. Proteins 2003; 53:182-92. [PMID: 14517970 DOI: 10.1002/prot.10495] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The interactions of nitric oxide (NO) and organic nitroso compounds with heme proteins are biologically important, and adduct formation between NO-containing compounds and myoglobin (Mb) have served as prototypical systems for studies of these interactions. We have prepared crystals of horse heart (hh) MbNO from nitrosylation of aqua-metMb crystals, and we have determined the crystal structure of hh MbNO at a resolution of 1.9 A. The Fe-N-O angle of 147 degrees in hh MbNO is larger than the corresponding 112 degrees angle previously determined from the crystal structure of sperm whale MbNO (Brucker et al., Proteins 1998;30:352-356) but is similar to the 150 degrees angle determined from a MS XAFS study of a frozen solution of hh MbNO (Rich et al., J Am Chem Soc 1998;120:10827-10836). The Fe-N(O) bond length of 2.0 A (this work) is longer than the 1.75 A distance determined from the XAFS study and suggests distal pocket influences on FeNO geometry. The nitrosyl N atom is located 3.0 A from the imidazole N(epsilon) atom of the distal His64 residue, suggesting electrostatic stabilization of the FeNO moiety by His64. The crystal structure of the nitrosoethane adduct of ferrous hh Mb was determined at a resolution of 1.7 A. The nitroso O atom of the EtNO ligand is located 2.7 A from the imidazole N(epsilon) atom of His64, suggesting a hydrogen bond interaction between these groups. To the best of our knowledge, the crystal structure of hh Mb(EtNO) is the first such determination of a nitrosoalkane adduct of a heme protein.
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Affiliation(s)
- Daniel M Copeland
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, USA
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13
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Travascio P, Witting PK, Mauk AG, Sen D. The peroxidase activity of a hemin--DNA oligonucleotide complex: free radical damage to specific guanine bases of the DNA. J Am Chem Soc 2001; 123:1337-48. [PMID: 11456705 DOI: 10.1021/ja0023534] [Citation(s) in RCA: 297] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A specific DNA oligonucleotide--hemin complex (PS2.M--hemin complex) that exhibits DNA-enhanced peroxidative activity was studied by EPR and UV--visible spectroscopy and by chemical probing analysis. EPR data obtained from low-temperature experiments on the PS2.M--hemin complex showed both a low-field g approximately 6 and a high-field g approximately 2 signal. These EPR signals are typical of high-spin ferric heme with axial symmetry as judged by the EPR spectrum of six-coordinate heme iron in acidic Fe(III)-myoglobin. This similarity is consistent with the presence of two axial ligands to the heme iron within the PS2.M--hemin complex, one of which is a water molecule. Optical analyses of the acid-base transition for the hemin complex yielded a pK(a) value for the water ligand of 8.70 +/- 0.03 (mean +/- SD). Low-temperature EPR analysis coupled with parallel spin-trapping investigations following the reaction of the PS2.M--hemin complex and hydrogen peroxide (H(2)O(2)) indicated the formation of a carbon-centered radical, most likely on the PS2.M oligonucleotide. Chemical probing analysis identified specific guanine bases within the PS2.M sequence that underwent oxidative damage upon reaction with H(2)O(2). These and other experimental findings support the hypothesis that the interaction of specific guanines of PS2.M with the bound hemin cofactor might contribute to the superior peroxidative activity of the PS2.M--hemin complex.
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Affiliation(s)
- P Travascio
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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14
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Indiani C, Feis A, Howes BD, Marzocchi MP, Smulevich G. Benzohydroxamic Acid−Peroxidase Complexes: Spectroscopic Characterization of a Novel Heme Spin Species. J Am Chem Soc 2000. [DOI: 10.1021/ja000587h] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chiara Indiani
- Contribution from the Dipartimento di Chimica, Università di Firenze, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Alessandro Feis
- Contribution from the Dipartimento di Chimica, Università di Firenze, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Barry D. Howes
- Contribution from the Dipartimento di Chimica, Università di Firenze, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Mario P. Marzocchi
- Contribution from the Dipartimento di Chimica, Università di Firenze, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Giulietta Smulevich
- Contribution from the Dipartimento di Chimica, Università di Firenze, Via G. Capponi 9, I-50121 Firenze, Italy
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15
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Boffi A, Das TK, della Longa S, Spagnuolo C, Rousseau DL. Pentacoordinate hemin derivatives in sodium dodecyl sulfate micelles: model systems for the assignment of the fifth ligand in ferric heme proteins. Biophys J 1999; 77:1143-9. [PMID: 10423459 PMCID: PMC1300405 DOI: 10.1016/s0006-3495(99)76965-1] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ferric iron protoporhyrin IX derivatives in SDS micelles have been investigated by means of visible absorption, resonance Raman, and XANES spectroscopies to establish specific correlations between the marker bands of the pentacoordinate derivatives obtained from the three different techniques. Hydroxyl and 1,2-dimethyl imidazole coordinated hemins display the typical spectroscopic marker bands of a pentacoordinate high-spin ferric iron derivative in both Raman and XANES spectra. In turn, the optical absorption spectra of these two derivatives are very different. This difference is in line with the assignment of hydroxyl as the fifth coordination ligand to free hemin in SDS micelles, as demonstrated by the isotopic shift of the frequency of Fe-OH bond with H(2)(18)O. The present assignments are relevant to the identification of the coordination state and the nature of the fifth ligand in ferric heme proteins.
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Affiliation(s)
- A Boffi
- CNR Centro di Biologia Molecolare, c/o Dipartimento di Scienze Biochimiche, Università "La Sapienza," 00185 Rome, Italy.
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Carraway AD, Miller GT, Pearce LL, Peterson J. The Alkaline Transition of Bis(N-acetylated) Heme Undecapeptide. Inorg Chem 1998; 37:4654-4661. [PMID: 11670617 DOI: 10.1021/ic971391u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alkaline forms of the ferric bis(N-acetylated) heme undecapeptide of cytochrome c (N-ac-HUP) and some of its derivatives have been studied by electronic absorption and electron paramagnetic resonance spectroscopies. Surprisingly, even at pH >12, no evidence could be found for the formation of a hydroxyl ion adduct, in direct contrast to a previous report concerning ferric heme peptides encapsulated in detergent micelles (Mazumdar et al. Inorg. Chem. 1991, 30, 700-705). A spectroscopically determined pK(a) of approximately 9 is assigned to the deprotonation of the constituent histidine ligand of heme iron in N-ac-HUP. The present findings are not entirely in keeping with those of an earlier study concerning the properties of N-acetylated heme octapeptide (Wang et al. J. Biol. Chem. 1992, 35, 15310-15318), the differences observed being attributed to the buffering media employed in the two investigations. The implications of the current results in relation to a better understanding of the alkaline transitions observed in hemoglobins and myoglobins is considered.
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Affiliation(s)
- Angela D. Carraway
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, Department of Mathematical and Physical Sciences, Northwestern State University of Louisiana, Natchitoches, Louisiana 71497, Department of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, and Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213
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Maurus R, Bogumil R, Nguyen NT, Mauk AG, Brayer G. Structural and spectroscopic studies of azide complexes of horse heart myoglobin and the His-64-->Thr variant. Biochem J 1998; 332 ( Pt 1):67-74. [PMID: 9576852 PMCID: PMC1219452 DOI: 10.1042/bj3320067] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The high-resolution X-ray crystallographic structures of horse heart azidometmyoglobin complexes of the wild-type protein and the His-64-->Thr variant have been determined to 2.0 and 1.8 A respectively. Azide binds to wild-type metmyoglobin in a bent configuration with an Fe-N-1-N-3 angle of 119 degrees and is oriented into the distal crevice in the direction of Ile-107. The proximity of the His-64 NE2 atom to the N-1 atom of the bound azide indicates stabilization of the ligand by the His-64 side chain through hydrogen bonding. In addition, structural characterization of wild-type horse heart azidometmyoglobin establishes that the only structural change induced by ligand binding is a small movement of the Leu-29 side chain away from the azide ligand. EPR and Fourier transform infrared spectroscopy were used to characterize the myoglobin azide complexes further. EPR spectroscopy revealed that, in contrast with wild-type azidometmyoglobin, two slightly different low-spin species are formed by azide bound to the His-64-->Thr variant both in solution and in a polycrystalline sample. One of these low-spin species has a greater relative intensity, with g values very similar to those of the azide complex of the wild-type protein. These EPR results together with structural information on this variant indicate the presence of two distinct conformations of bound azide, with one form predominating. The major conformation is comparable to that formed by wild-type myoglobin in which azide is oriented into the distal crevice. In the minor conformation the azide is oriented towards the exterior of the protein.
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Affiliation(s)
- R Maurus
- Department of Biochemistry and Molecular Biology and the Protein Engineering Network of Centres of Excellence, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Liu Y, Moënne-Loccoz P, Loehr TM, Ortiz de Montellano PR. Heme oxygenase-1, intermediates in verdoheme formation and the requirement for reduction equivalents. J Biol Chem 1997; 272:6909-17. [PMID: 9054378 DOI: 10.1074/jbc.272.11.6909] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Conversion of heme to verdoheme by heme oxygenase-1 (HO-1) is thought to involve alpha-meso-hydroxylation and elimination of the meso-carbon as CO, a reaction supported by both H2O2 and NADPH-cytochrome P450 reductase/O2. Anaerobic reaction of the heme-HO-1 complex with 1 eq of H2O2 produces an enzyme-bound intermediate identified by spectroscopic methods as alpha-meso-hydroxyheme. This is the first direct evidence for HO-1-catalyzed formation of alpha-meso-hydroxyheme. alpha-meso-Hydroxyheme exists as a mixture of Fe(III) phenolate, Fe(III) keto anion, and Fe(II) keto pi neutral radical resonance structures. EPR shows that complexation with CO enhances the Fe(II) pi neutral radical component. Reaction of the alpha-meso-hydroxyheme-HO-1 complex with O2 generates Fe(III) verdoheme, which can be reduced in the presence of CO to the Fe(II) verdoheme-CO complex. Thus, conversion of alpha-meso-hydroxyheme to Fe(III) verdoheme, in contrast to a previous report (Matera, K. M., Takahashi, S., Fujii, H., Zhou, H., Ishikawa, K., Yoshimura, T., Rousseau, D. L., Yoshida, T., and Ikeda-Saito, M. (1996) J. Biol. Chem. 271, 6618-6624), does not require a reducing equivalent. An electron is only required to reduce ferric to ferrous verdoheme in the first step of its conversion to biliverdin.
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Affiliation(s)
- Y Liu
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, California 94143-0446, USA
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Affiliation(s)
- Masanori Sono
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
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