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Lu X, Wang S, Qin JH. Isolating Fe-O2 Intermediates in Dioxygen Activation by Iron Porphyrin Complexes. Molecules 2022; 27:molecules27154690. [PMID: 35897870 PMCID: PMC9332324 DOI: 10.3390/molecules27154690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/12/2022] [Accepted: 07/18/2022] [Indexed: 11/30/2022] Open
Abstract
Dioxygen (O2) is an environmentally benign and abundant oxidant whose utilization is of great interest in the design of bioinspired synthetic catalytic oxidation systems to reduce energy consumption. However, it is unfortunate that utilization of O2 is a significant challenge because of the thermodynamic stability of O2 in its triplet ground state. Nevertheless, nature is able to overcome the spin state barrier using enzymes, which contain transition metals with unpaired d-electrons facilitating the activation of O2 by metal coordination. This inspires bioinorganic chemists to synthesize biomimetic small-molecule iron porphyrin complexes to carry out the O2 activation, wherein Fe-O2 species have been implicated as the key reactive intermediates. In recent years, a number of Fe-O2 intermediates have been synthesized by activating O2 at iron centers supported on porphyrin ligands. In this review, we focus on a few examples of these advances with emphasis in each case on the particular design of iron porphyrin complexes and particular reaction environments to stabilize and isolate metal-O2 intermediates in dioxygen activation, which will provide clues to elucidate structures of reactive intermediates and mechanistic insights in biological processes.
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2
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Singha A, Das PK, Dey A. Resonance Raman Spectroscopy and Density Functional Theory Calculations on Ferrous Porphyrin Dioxygen Adducts with Different Axial Ligands: Correlation of Ground State Wave Function and Geometric Parameters with Experimental Vibrational Frequencies. Inorg Chem 2019; 58:10704-10715. [PMID: 31356064 DOI: 10.1021/acs.inorgchem.9b00656] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A dioxygen adduct of ferrous porphyrin is an important chemical species in nature as it is a common intermediate in all oxygen transfer, storage, reducing, and activating heme enzymes. The ground state (GS) wave function of this complex has been investigated using several techniques like resonance Raman (rR), Mossbauer, and X-ray absorption spectroscopies. The Fe-O and O-O vibrations of these six-coordinated diamagnetic species show a positive correlation with each other in contrast to analogous ferrous carbonyl complexes where the Fe-CO vibration correlates negatively with the C-O vibration due to a synergistic effect. In this Article, three Fe-porphyrins with different axial ligands (imidazole, phenolate, and thiolate) are investigated using rR spectroscopy and density functional theory (DFT) calculations. The GS wave functions of these species are analyzed, and the contribution of the three primary bonding interactions in the Fe-O2 unit (a σ interaction from the in-plane π* of the superoxide to the vacant dz2 of Fe, a π donation from the out of plane (oop) π* to the dπ orbital of Fe, and a π back bonding interaction from the dπ orbital of Fe to the oop π* of the superoxide) to the calculated Fe-O and O-O vibrations and bond lengths are deconvoluted using a MO theory framework. The GS wave function provides a basis for the correlations observed between different vibrational and geometric parameters of these dioxygen adducts. Furthermore, the correlations obtained allows estimation of the GS wave function and geometry of these species (both natural and artificial) using their experimentally observed Fe-O/O-O vibrations. The wave functions thus extracted from the experimental vibrational data reported offer insight into the role of the axial ligand and hydrogen bonding on the geometric and electronic structures of these crucial chemical species in different protein active sites.
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Affiliation(s)
- Asmita Singha
- School of Chemical Science , Indian Association for the Cultivation of Science , Kolkata , India 700032
| | - Pradip Kumar Das
- School of Chemical Science , Indian Association for the Cultivation of Science , Kolkata , India 700032
| | - Abhishek Dey
- School of Chemical Science , Indian Association for the Cultivation of Science , Kolkata , India 700032
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3
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Adam SM, Wijeratne GB, Rogler PJ, Diaz DE, Quist DA, Liu JJ, Karlin KD. Synthetic Fe/Cu Complexes: Toward Understanding Heme-Copper Oxidase Structure and Function. Chem Rev 2018; 118:10840-11022. [PMID: 30372042 PMCID: PMC6360144 DOI: 10.1021/acs.chemrev.8b00074] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heme-copper oxidases (HCOs) are terminal enzymes on the mitochondrial or bacterial respiratory electron transport chain, which utilize a unique heterobinuclear active site to catalyze the 4H+/4e- reduction of dioxygen to water. This process involves a proton-coupled electron transfer (PCET) from a tyrosine (phenolic) residue and additional redox events coupled to transmembrane proton pumping and ATP synthesis. Given that HCOs are large, complex, membrane-bound enzymes, bioinspired synthetic model chemistry is a promising approach to better understand heme-Cu-mediated dioxygen reduction, including the details of proton and electron movements. This review encompasses important aspects of heme-O2 and copper-O2 (bio)chemistries as they relate to the design and interpretation of small molecule model systems and provides perspectives from fundamental coordination chemistry, which can be applied to the understanding of HCO activity. We focus on recent advancements from studies of heme-Cu models, evaluating experimental and computational results, which highlight important fundamental structure-function relationships. Finally, we provide an outlook for future potential contributions from synthetic inorganic chemistry and discuss their implications with relevance to biological O2-reduction.
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Affiliation(s)
- Suzanne M. Adam
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Gayan B. Wijeratne
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Patrick J. Rogler
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Daniel E. Diaz
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - David A. Quist
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Jeffrey J. Liu
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Kenneth D. Karlin
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
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4
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Atkins CG, Buckley K, Blades MW, Turner RFB. Raman Spectroscopy of Blood and Blood Components. APPLIED SPECTROSCOPY 2017; 71:767-793. [PMID: 28398071 DOI: 10.1177/0003702816686593] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Blood is a bodily fluid that is vital for a number of life functions in animals. To a first approximation, blood is a mildly alkaline aqueous fluid (plasma) in which a large number of free-floating red cells (erythrocytes), white cells (leucocytes), and platelets are suspended. The primary function of blood is to transport oxygen from the lungs to all the cells of the body and move carbon dioxide in the return direction after it is produced by the cells' metabolism. Blood also carries nutrients to the cells and brings waste products to the liver and kidneys. Measured levels of oxygen, nutrients, waste, and electrolytes in blood are often used for clinical assessment of human health. Raman spectroscopy is a non-destructive analytical technique that uses the inelastic scattering of light to provide information on chemical composition, and hence has a potential role in this clinical assessment process. Raman spectroscopic probing of blood components and of whole blood has been on-going for more than four decades and has proven useful in applications ranging from the understanding of hemoglobin oxygenation, to the discrimination of cancerous cells from healthy lymphocytes, and the forensic investigation of crime scenes. In this paper, we review the literature in the field, collate the published Raman spectroscopy studies of erythrocytes, leucocytes, platelets, plasma, and whole blood, and attempt to draw general conclusions on the state of the field.
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Affiliation(s)
- Chad G Atkins
- 1 Michael Smith Laboratories, The University of British Columbia, Canada
- 2 Department of Chemistry, The University of British Columbia, Canada
| | - Kevin Buckley
- 1 Michael Smith Laboratories, The University of British Columbia, Canada
- 3 Nanoscale Biophotonics Laboratory, National University of Ireland, Ireland
| | - Michael W Blades
- 2 Department of Chemistry, The University of British Columbia, Canada
| | - Robin F B Turner
- 1 Michael Smith Laboratories, The University of British Columbia, Canada
- 2 Department of Chemistry, The University of British Columbia, Canada
- 4 Department of Electrical and Computer Engineering, The University of British Columbia, Canada
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5
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Smith AT, Marvin KA, Freeman KM, Kerby RL, Roberts GP, Burstyn JN. Identification of Cys94 as the distal ligand to the Fe(III) heme in the transcriptional regulator RcoM-2 from Burkholderia xenovorans. J Biol Inorg Chem 2012; 17:1071-82. [PMID: 22855237 PMCID: PMC3484680 DOI: 10.1007/s00775-012-0920-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 07/03/2012] [Indexed: 10/28/2022]
Abstract
The CO-responsive transcriptional regulator RcoM from Burkholderia xenovorans (BxRcoM) was recently identified as a Cys(thiolate)-ligated heme protein that undergoes a redox-mediated ligand switch; however, the Cys bound to the Fe(III) heme was not identified. To that end, we generated and purified three Cys-to-Ser variants of BxRcoM-2--C94S, C127S, and C130S--and examined their spectroscopic properties in order to identify the native Cys(thiolate) ligand. Electronic absorption, resonance Raman, and electron paramagnetic resonance (EPR) spectroscopies demonstrate that the C127S and C130S variants, like wild-type BxRcoM-2, bind a six-coordinate low-spin Fe(III) heme using a Cys/His ligation motif. In contrast, electronic absorption and resonance Raman spectra of the C94S variant are most consistent with a mixture of five-coordinate high-spin and six-coordinate low-spin Fe(III) heme, neither of which are ligated by a Cys(thiolate) ligand. The EPR spectrum of C94S is dominated by a large, axial high-spin Fe(III) signal, confirming that the native ligation motif is not maintained in this variant. Together, these data reveal that Cys(94) is the distal Fe(III) heme ligand in BxRcoM-2; by sequence alignment, Cys(94) is also implicated as the distal Fe(III) heme ligand in BxRcoM-1, another homologue found in the same organism.
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Affiliation(s)
- Aaron T. Smith
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Katherine A. Marvin
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Katherine M. Freeman
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Robert L. Kerby
- Department of Bacteriology, University of Wisconsin–Madison, 1550 Linden Drive, Madison, WI 53706, USA
| | - Gary P. Roberts
- Department of Bacteriology, University of Wisconsin–Madison, 1550 Linden Drive, Madison, WI 53706, USA
| | - Judith N. Burstyn
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706, USA
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Li P, Kong B, Chen Q, Zheng D, Liu N. Formation and identification of nitrosylmyoglobin by Staphylococcus xylosus in raw meat batters: a potential solution for nitrite substitution in meat products. Meat Sci 2012; 93:67-72. [PMID: 22926033 DOI: 10.1016/j.meatsci.2012.08.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 03/31/2012] [Accepted: 08/01/2012] [Indexed: 10/28/2022]
Abstract
Staphylococcus xylosus and Pediococcus pentosaceus isolated from Chinese dried sausage were assessed for their ability to convert metmyoglobin into nitrosylmyoglobin in Mann-Rogosa-Sharp broth model systems and raw pork meat batters without the addition of nitrite. The results showed that samples in model systems with S. xylosus cultures had an absorption spectra that is typical of nitrosylmyoglobin, an obvious pink colour (judged by visual inspection) and a significantly higher a-value than the control samples or samples inoculated with P. pentosaceus. In raw meat batters, the a-values of the S. xylosus samples were almost the same as those for the meat with nitrite added. The complementary analysis of meat batter samples by photochemical information from UV-vis, electron spin resonance and resonance Raman spectroscopy revealed that the existing status of the myoglobin in meat batters inoculated with S. xylosus was mainly pentacoordinate nitrosylmyoglobin. This study provides a potential solution for nitrite substitute in meat products.
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Affiliation(s)
- Peijun Li
- College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China
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7
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Moeser B, Janoschka A, Wolny JA, Paulsen H, Filippov I, Berry RE, Zhang H, Chumakov AI, Walker FA, Schünemann V. Nuclear inelastic scattering and Mössbauer spectroscopy as local probes for ligand binding modes and electronic properties in proteins: vibrational behavior of a ferriheme center inside a β-barrel protein. J Am Chem Soc 2012; 134:4216-28. [PMID: 22295945 DOI: 10.1021/ja210067t] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In this work, we present a study of the influence of the protein matrix on its ability to tune the binding of small ligands such as NO, cyanide (CN(-)), and histamine to the ferric heme iron center in the NO-storage and -transport protein Nitrophorin 2 (NP2) from the salivary glands of the blood-sucking insect Rhodnius prolixus. Conventional Mössbauer spectroscopy shows a diamagnetic ground state of the NP2-NO complex and Type I and II electronic ground states of the NP2-CN(-) and NP2-histamine complex, respectively. The change in the vibrational signature of the protein upon ligand binding has been monitored by Nuclear Inelastic Scattering (NIS), also called Nuclear Resonant Vibrational Spectroscopy (NRVS). The NIS data thus obtained have also been calculated by quantum mechanical (QM) density functional theory (DFT) coupled with molecular mechanics (MM) methods. The calculations presented here show that the heme ruffling in NP2 is a consequence of the interaction with the protein matrix. Structure optimizations of the heme and its ligands with DFT retain the characteristic saddling and ruffling only if the protein matrix is taken into account. Furthermore, simulations of the NIS data by QM/MM calculations suggest that the pH dependence of the binding of NO, but not of CN(-) and histamine, might be a consequence of the protonation state of the heme carboxyls.
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Affiliation(s)
- Beate Moeser
- Technische Universität Kaiserslautern, Fachbereich Physik, Erwin-Schrödinger-Str. 56, D-67663 Kaiserslautern, Germany
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8
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Jones EM, Balakrishnan G, Spiro TG. Heme reactivity is uncoupled from quaternary structure in gel-encapsulated hemoglobin: a resonance Raman spectroscopic study. J Am Chem Soc 2012; 134:3461-71. [PMID: 22263778 PMCID: PMC3307588 DOI: 10.1021/ja210126j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Encapsulation of hemoglobin (Hb) in silica gel preserves structure and function but greatly slows protein motion, thereby providing access to intermediates along the allosteric pathway that are inaccessible in solution. Resonance Raman (RR) spectroscopy with visible and ultraviolet laser excitation provides probes of heme reactivity and of key tertiary and quaternary contacts. These probes were monitored in gels after deoxygenation of oxyHb and after CO binding to deoxyHb, which initiate conformational change in the R-T and T-R directions, respectively. The spectra establish that quaternary structure change in the gel takes a week or more but that the evolution of heme reactivity, as monitored by the Fe-histidine stretching vibration, ν(FeHis), is completed within two days, and is therefore uncoupled from the quaternary structure. Within each quaternary structure, the evolving ν(FeHis) frequencies span the full range of values between those previously associated with the high- and low-affinity end states, R and T. This result supports the tertiary two-state (TTS) model, in which the Hb subunits can adopt high- and low-affinity tertiary structures, r and t, within each quaternary state. The spectra also reveal different tertiary pathways, involving the breaking and reformation of E and F interhelical contacts in the R-T direction but not the T-R direction. In the latter, tertiary motions are restricted by the T quaternary contacts.
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Affiliation(s)
- Eric M. Jones
- Department of Chemistry, University of Washington, Box 351700, Seattle Washington 98195-1700 USA
| | - Gurusamy Balakrishnan
- Department of Chemistry, University of Washington, Box 351700, Seattle Washington 98195-1700 USA
| | - Thomas G. Spiro
- Department of Chemistry, University of Washington, Box 351700, Seattle Washington 98195-1700 USA
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Li J, Peng Q, Barabanschikov A, Pavlik JW, Alp EE, Sturhahn W, Zhao J, Schulz CE, Sage JT, Scheidt WR. New perspectives on iron-ligand vibrations of oxyheme complexes. Chemistry 2011; 17:11178-85. [PMID: 21922552 PMCID: PMC3234299 DOI: 10.1002/chem.201101352] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Indexed: 11/12/2022]
Abstract
We report our studies of the vibrational dynamics of iron for three imidazole-ligated oxyheme derivatives that mimic the active sites of histidine-ligated heme proteins complexed with dioxygen. The experimental vibrational data are obtained from nuclear resonance vibrational spectroscopy (NRVS) measurements conducted on both powder samples and oriented single crystals, and which includes several in-plane (ip) and out-of-plane (oop) measurements. Vibrational spectral assignments have been made through a combination of the oriented sample spectra and predictions based on density functional theory (DFT) calculations. The two Fe-O(2) modes that have been previously observed by resonance Raman spectroscopy in heme proteins are clearly shown to be very strongly mixed and are not simply either a bending or stretching mode. In addition, a third Fe-O(2) mode, not previously reported, has been identified. The long-sought Fe-Im stretch, not observed in resonance Raman spectra, has been identified and compared with the frequencies observed for the analogous CO and NO species. The studies also suggest that the in-plane iron motion is anisotropic and is controlled by the orientation of the Fe-O(2) group and not sensitive to the in-plane Fe-N(p) bonds and/or imidazole orientations.
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Affiliation(s)
- Jianfeng Li
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (USA), Fax (574) 631-6652
| | - Qian Peng
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (USA), Fax (574) 631-6652
| | - Alexander Barabanschikov
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115 (USA)
| | - Jeffrey W. Pavlik
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (USA), Fax (574) 631-6652
| | - E. Ercan Alp
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (USA)
| | - Wolfgang Sturhahn
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (USA)
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (USA)
| | - Charles E. Schulz
- Department of Physics, Knox College, Galesburg, Illinois 61401 (USA)
| | - J. Timothy Sage
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115 (USA)
| | - W. Robert Scheidt
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (USA), Fax (574) 631-6652
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Lehnert N, Sage JT, Silvernail N, Scheidt WR, Alp EE, Sturhahn W, Zhao J. Oriented single-crystal nuclear resonance vibrational spectroscopy of [Fe(TPP)(MI)(NO)]: quantitative assessment of the trans effect of NO. Inorg Chem 2010; 49:7197-215. [PMID: 20586416 PMCID: PMC2917100 DOI: 10.1021/ic1010677] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper presents oriented single-crystal Nuclear Resonance Vibrational Spectroscopy (NRVS) data for the six-coordinate (6C) ferrous heme-nitrosyl model complex [(57)Fe(TPP)(MI)(NO)] (1; TPP(2-) = tetraphenylporphyrin dianion; MI = 1-methylimidazole). The availability of these data enables for the first time the detailed simulation of the complete NRVS data, including the porphyrin-based vibrations, of a 6C ferrous heme-nitrosyl, using our quantum chemistry centered normal coordinate analysis (QCC-NCA). Importantly, the Fe-NO stretch is split by interaction with a porphyrin-based vibration into two features, observed at 437 and 472 cm(-1). The 437 cm(-1) feature is strongly out-of-plane (oop) polarized and shows a (15)N(18)O isotope shift of 8 cm(-1) and is therefore assigned to nu(Fe-NO). The admixture of Fe-N-O bending character is small. Main contributions to the Fe-N-O bend are observed in the 520-580 cm(-1) region, distributed over a number of in-plane (ip) polarized porphyrin-based vibrations. The main component, assigned to delta(ip)(Fe-N-O), is identified with the feature at 563 cm(-1). The Fe-N-O bend also shows strong mixing with the Fe-NO stretching internal coordinate, as evidenced by the oop NRVS intensity in the 520-580 cm(-1) region. Very accurate normal mode descriptions of nu(Fe-NO) and delta(ip)(Fe-N-O) have been obtained in this study. These results contradict previous interpretations of the vibrational spectra of 6C ferrous heme-nitrosyls where the higher energy feature at approximately 550 cm(-1) had usually been associated with nu(Fe-NO). Furthermore, these results provide key insight into NO binding to ferrous heme active sites in globins and other heme proteins, in particular with respect to (a) the effect of hydrogen bonding to the coordinated NO and (b) changes in heme dynamics upon NO coordination. [Fe(TPP)(MI)(NO)] constitutes an excellent model system for ferrous NO adducts of myoglobin (Mb) mutants where the distal histidine (His64) has been removed. Comparison to the reported vibrational data for wild-type (wt) Mb-NO then shows that the effect of H bonding to the coordinated NO is weak and mostly leads to a polarization of the pi/pi* orbitals of bound NO. In addition, the observation that delta(ip)(Fe-N-O) does not correlate well with nu(N-O) can be traced back to the very mixed nature of this mode. The Fe-N(imidazole) stretching frequency is observed at 149 cm(-1) in [Fe(TPP)(MI)(NO)], and spectral changes upon NO binding to five-coordinate ferrous heme active sites are discussed. The obtained high-quality force constants for the Fe-NO and N-O bonds of 2.57 and 11.55 mdyn/A can further be compared to those of corresponding 5C species, which allows for a quantitative analysis of the sigma trans interaction between the proximal imidazole (His) ligand and NO. This is key for the activation of the NO sensor soluble guanylate cyclase. Finally, DFT methods are calibrated against the experimentally determined vibrational properties of the Fe-N-O subunit in 1. DFT is in fact incapable of reproducing the vibrational energies and normal mode descriptions of the Fe-N-O unit well, and thus, DFT-based predictions of changes in vibrational properties upon heme modification or other perturbations of these 6C complexes have to be treated with caution.
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Affiliation(s)
- Nicolai Lehnert
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - J. Timothy Sage
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA 02115, USA
| | - Nathan Silvernail
- Department of Chemistry and Biochemistry, 251 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556, USA
| | - W. Robert Scheidt
- Department of Chemistry and Biochemistry, 251 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556, USA
| | - E. Ercan Alp
- Argonne National Laboratory, APS/XFD, 431/D003, Argonne, IL 60439, USA
| | - Wolfgang Sturhahn
- Argonne National Laboratory, APS/XFD, 431/D003, Argonne, IL 60439, USA
| | - Jiyong Zhao
- Argonne National Laboratory, APS/XFD, 431/D003, Argonne, IL 60439, USA
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11
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Ikemura K, Mukai M, Shimada H, Tsukihara T, Yamaguchi S, Shinzawa-Itoh K, Yoshikawa S, Ogura T. Red-excitation resonance Raman analysis of the nu(Fe=O) mode of ferryl-oxo hemoproteins. J Am Chem Soc 2008; 130:14384-5. [PMID: 18847201 DOI: 10.1021/ja805735g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Raman excitation profile of the nuFe O mode of horseradish peroxidase compound II exhibits a maximum at 580 nm. This maximum is located within an absorption band with a shoulder assignable to an oxygen-to-iron charge transfer band on the longer wavelength side of the alpha-band. Resonance Raman bands of the nuFe O mode of various ferryl-oxo type hemoproteins measured at 590 nm excitation indicate that many hemoproteins in the ferryl-oxo state have an oxygen-to-iron charge transfer band in the visible region. Since this red-excited resonance Raman technique causes much less photochemical damage in the proteins relative to blue-excited resonance Raman spectroscopy, it produces a higher signal-to-noise ratio and thus represents a powerful tool for investigations of ferryl-oxo intermediates of hemoproteins.
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Affiliation(s)
- Kenichiro Ikemura
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Hyogo, Japan
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12
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Leu BM, Silvernail NJ, Zgierski MZ, Wyllie GRA, Ellison MK, Scheidt WR, Zhao J, Sturhahn W, Alp EE, Sage JT. Quantitative vibrational dynamics of iron in carbonyl porphyrins. Biophys J 2007; 92:3764-83. [PMID: 17350996 PMCID: PMC1868970 DOI: 10.1529/biophysj.106.093773] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We use nuclear resonance vibrational spectroscopy and computational predictions based on density functional theory (DFT) to explore the vibrational dynamics of (57)Fe in porphyrins that mimic the active sites of histidine-ligated heme proteins complexed with carbon monoxide. Nuclear resonance vibrational spectroscopy yields the complete vibrational spectrum of a Mössbauer isotope, and provides a valuable probe that is not only selective for protein active sites but quantifies the mean-squared amplitude and direction of the motion of the probe nucleus, in addition to vibrational frequencies. Quantitative comparison of the experimental results with DFT calculations provides a detailed, rigorous test of the vibrational predictions, which in turn provide a reliable description of the observed vibrational features. In addition to the well-studied stretching vibration of the Fe-CO bond, vibrations involving the Fe-imidazole bond, and the Fe-N(pyr) bonds to the pyrrole nitrogens of the porphyrin contribute prominently to the observed experimental signal. All of these frequencies show structural sensitivity to the corresponding bond lengths, but previous studies have failed to identify the latter vibrations, presumably because the coupling to the electronic excitation is too small in resonance Raman measurements. We also observe the FeCO bending vibrations, which are not Raman active for these unhindered model compounds. The observed Fe amplitude is strongly inconsistent with three-body oscillator descriptions of the FeCO fragment, but agrees quantitatively with DFT predictions. Over the past decade, quantum chemical calculations have suggested revised estimates of the importance of steric distortion of the bound CO in preventing poisoning of heme proteins by carbon monoxide. Quantitative agreement with the predicted frequency, amplitude, and direction of Fe motion for the FeCO bending vibrations provides direct experimental support for the quantum chemical description of the energetics of the FeCO unit.
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Affiliation(s)
- Bogdan M Leu
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts, USA
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Balland V, Bouzhir-Sima L, Kiger L, Marden MC, Vos MH, Liebl U, Mattioli TA. Role of Arginine 220 in the Oxygen Sensor FixL from Bradyrhizobium japonicum. J Biol Chem 2005; 280:15279-88. [PMID: 15711013 DOI: 10.1074/jbc.m413928200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the heme-based oxygen sensor protein FixL, conformational changes induced by oxygen binding to the heme sensor domain regulate the activity of a neighboring histidine kinase, eventually restricting expression of specific genes to hypoxic conditions. The conserved arginine 220 residue is suggested to play a key role in the signal transduction mechanism. To obtain detailed insights into the role of this residue, we replaced Arg(220) by histidine (R220H), glutamine (R220Q), glutamate (R220E), and isoleucine (R220I) in the heme domain FixLH from Bradyrhizobium japonicum. These mutations resulted in dramatic changes in the O(2) affinity with K(d) values in the order R220I < R220Q < wild type < R220H. For the R220H and R220Q mutants, residue 220 interacts with the bound O(2) or CO ligands, as seen by resonance Raman spectroscopy. For the oxy-adducts, this H-bond modifies the pi acidity of the O(2) ligand, and its strength is correlated with the back-bonding-sensitive nu(4) frequency, the k(off) value for O(2) dissociation, and heme core-size conformational changes. This effect is especially strong for the wild-type protein where Arg(220) is, in addition, positively charged. These observations strongly suggest that neither strong ligand fixation nor the displacement of residue 220 into the heme distal pocket are solely responsible for the reported heme conformational changes associated with kinase activity regulation, but that a significant decrease of the heme pi(*) electron density because of strong back-bonding toward the oxygen ligand also plays a key role.
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Affiliation(s)
- Véronique Balland
- Laboratoire de Biophysique du Stress Oxydant, SBE/DBJC and CNRS URA 2096, CEA/Saclay, 91191 Gif-sur-Yvette cedex, France
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14
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Mackin H, Benko B, Yu NT, Gersonde K. Resonance Raman study on pentacoordinated and hexacoordinated ferrous nitrosyl myoglobin. FEBS Lett 2001. [DOI: 10.1016/0014-5793(83)80577-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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Podstawka E, Kincaid JR, Proniewicz LM. Resonance Raman studies of selectively labelled hemoglobin tetramers. J Mol Struct 2001. [DOI: 10.1016/s0022-2860(01)00705-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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16
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Das TK, Couture M, Guertin M, Rousseau DL. Distal Interactions in the Cyanide Complex of Ferric Chlamydomonas Hemoglobin. J Phys Chem B 2000. [DOI: 10.1021/jp000452y] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tapan Kanti Das
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, and Department of Biochemistry and Microbiology, Faculty of Sciences and Engineering, Laval University, Quebec, G1K 7P4, Canada
| | - Manon Couture
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, and Department of Biochemistry and Microbiology, Faculty of Sciences and Engineering, Laval University, Quebec, G1K 7P4, Canada
| | - Michel Guertin
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, and Department of Biochemistry and Microbiology, Faculty of Sciences and Engineering, Laval University, Quebec, G1K 7P4, Canada
| | - Denis L. Rousseau
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, and Department of Biochemistry and Microbiology, Faculty of Sciences and Engineering, Laval University, Quebec, G1K 7P4, Canada
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17
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Rich AM, Armstrong RS, Ellis PJ, Lay PA. Determination of the Fe−Ligand Bond Lengths and Fe−N−O Bond Angles in Horse Heart Ferric and Ferrous Nitrosylmyoglobin Using Multiple-Scattering XAFS Analyses. J Am Chem Soc 1998. [DOI: 10.1021/ja980253g] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anne M. Rich
- Contribution from the School of Chemistry, University of Sydney, New South Wales 2006, Australia
| | - Robert S. Armstrong
- Contribution from the School of Chemistry, University of Sydney, New South Wales 2006, Australia
| | - Paul J. Ellis
- Contribution from the School of Chemistry, University of Sydney, New South Wales 2006, Australia
| | - Peter A. Lay
- Contribution from the School of Chemistry, University of Sydney, New South Wales 2006, Australia
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18
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Zhu L, Widom A, Champion PM. A multidimensional Landau-Zener description of chemical reaction dynamics and vibrational coherence. J Chem Phys 1997. [DOI: 10.1063/1.474645] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Affiliation(s)
- E V Arnold
- Department of Chemistry, University of Wyoming, Laramie, 82071, USA
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20
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Low frequency vibrational modes of oxygenated myoglobin, hemoglobins, and modified derivatives. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47388-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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21
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Abstract
Femtosecond laser pulses, resonant with Soret band of the nitric oxide complex of myoglobin (MbNO), were used to probe coherent, low-frequency nuclear motion of the heme group after photolysis. Distinct oscillations with periods of 430 and 150 femtoseconds were observed and are attributed to heme doming and iron-histidine motion, respectively. These results verify that the nuclear motion of the heme is strongly coupled to the ligand binding reaction and demonstrate that such motion is not determined by overdamped (diffusive) dynamics. The relative phases and frequencies of the nuclear motion of the photoproduct suggest that the coherence arises from impulsive electronic forces associated with the spin-state change of the heme iron atom and the depopulation of its dz2 orbital during the bond-breaking event.
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Affiliation(s)
- L Zhu
- Department of Physics, Northeastern University, Boston, MA 02115
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22
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Bersuker I, Stavrov S. Structure and properties of metalloporphyrins and hemoproteins: the vibronic approach. Coord Chem Rev 1988. [DOI: 10.1016/0010-8545(88)80001-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Smulevich G, Mauro JM, Fishel LA, English AM, Kraut J, Spiro TG. Cytochrome c peroxidase mutant active site structures probed by resonance Raman and infrared signatures of the CO adducts. Biochemistry 1988; 27:5486-92. [PMID: 2846040 DOI: 10.1021/bi00415a015] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Vibrational frequencies associated with FeC and CO stretching and FeCO bending modes have been determined via resonance Raman (RR) and infrared (IR) spectroscopy for cytochrome c peroxidase (CCP) mutants prepared by site-directed mutagenesis. These include the bacterial "wild type", CCP(MI), and mutations involving groups on the proximal (Asp-235----Asn; Trp-191---Phe) and distal (Trp-51----Phe; Arg-48----Leu and Lys) side of the heme. The data were analyzed with the aid of a recently established correlation between nu FeC and nu CO, which can be used to distinguish between back-bonding and axial ligand donor effects. At high pH all adducts showed essentially the same vibrational pattern (form I') with nu FeC approximately 505 cm-1, nu CO approximately 1948 cm-1, and delta FeCO (weak RR band) approximately 576 cm-1. These frequencies are very similar to those shown by the myoglobin CO adduct and imply a "normal" H-bond of the proximal histidine. At pH 7 (pH 6 for Asn-235 and Leu-48), different forms are seen for different proteins: form I (nu FeC approximately 500 cm-1, nu CO = 1922-1941 cm-1, and delta FeCO approximately 580 cm-1, very weak) in the case of CCP(MI) and Phe-191, as well as bakers' yeast CCP, or form II (nu FeC approximately 530 cm-1, nu CO = 1922-1933 cm-1, and delta FeCO = 585 cm-1, moderately strong) for Asn-235 and Phe-51.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G Smulevich
- Dipartimento di Chimica, Università di Firenze, Italy
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24
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Rousseau DL, Singh S, Ching YC, Sassaroli M. Nitrosyl cytochrome c oxidase. Formation and properties of mixed valence enzyme. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)60619-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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25
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Owens JW, O'Connor CJ. Comparison of the electronic and vibrational spectra of complexes of protoporphyrin-IX, hemeoctapeptide, and heme proteins. Coord Chem Rev 1988. [DOI: 10.1016/0010-8545(88)80030-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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26
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Atamian M, Bocian DF. Resonance Raman studies of acetylheme-reconstituted myoglobins. Characterization of 2- versus 4-substituent/protein interactions. Biochemistry 1987; 26:8319-26. [PMID: 3442657 DOI: 10.1021/bi00399a044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Resonance Raman (RR) spectra are reported for the deoxy, oxy, and metcyano species of sperm whale myoglobin (Mb) reconstituted with deuteroheme, 2-acetyldeuteroheme, 4-acetyldeuteroheme, and 2,4-diacetyldeuteroheme. The functional inequivalence of the 2- and 4-positions of the heme moiety is manifested in the vibrational frequencies of the carbonyl and certain heme skeletal modes. The RR data indicate that the protein influences the porphyrin pi-system primarily through the 2-substituent. In the deoxy Mbs, the 2-acetyl group is more conjugated into the pi-macrocycle than the 4-acetyl group. In the ligated Mbs, the extent of conjugation of the 2-group is less than in the deoxy forms. This result indicates that ligand binding differentially alters the pi-electronic structure for 2- vs 4-substituted systems. The proximal histidine-iron stretching vibration of all four deoxy Mbs occurs at 222 +/- 1 cm-1, which indicates that the substituent-induced changes in the pi-electronic structure do not result in large changes of the electron density in the axial ligand bonds. RR spectra recorded immediately after heme reconstitution indicate the presence of two inequivalent forms of the protein. 1H NMR spectroscopy indicates that these two forms are the normal and reversed heme orientational isomers previously described by La Mar and co-workers [La Mar, G.N., Budd, D.L., Viscio, D.B., Smith, K.M., & Langry, K.C. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 5755-5759]. The RR spectra demonstrate that in the deoxy species the 2-acetyl group of the normal form is conjugated into the macrocycle to approximately the same extent as the 4-acetyl group of the reversed form and vice versa.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M Atamian
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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27
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Yu NT, Thompson HM, Mizukami H, Gersonde K. The cobalt-nitrosyl stretching vibration as a sensitive resonance Raman probe for distal histidine-nitrosyl interaction in monomeric hemoglobins. EUROPEAN JOURNAL OF BIOCHEMISTRY 1986; 159:129-32. [PMID: 3743568 DOI: 10.1111/j.1432-1033.1986.tb09842.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The Co-NO stretching vibration has been assigned in the resonance Raman spectra of various cobalt-substituted monomeric hemoglobins by employing isotope-labeling of nitrosyl (14N16O, 15N16O, 14N18O). Monomeric hemoglobins with a distal histidine (sperm whale myoglobin and leghemoglobin) exhibit this vibration at 573-575 cm-1, whereas hemoglobins without distal histidine (elephant myoglobin and insect hemoglobin from Chironomus thummi thummi, CTT III) show this vibration in the range of 553-558 cm-1. The Fe-NO stretching vibration which occurs in the range of 554-556 cm-1 does not reflect the distal histidine-ligand interaction. Therefore, the Co-NO moiety which is isoelectronic with the Fe-O2 moiety is a good monitor for distal effects on the exogenous ligand of hemoglobins, especially due to the fact that in hemoglobins with distal histidine the Fe-O2 stretching vibration (567-572 cm-1) is similar to the Co-NO stretching vibration.
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28
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Gersonde K, Kerr E, Yu NT, Parish DW, Smith KM. Resonance Raman investigation of CO-ligated monomeric insect hemoglobins. Direct evidence for reciprocal changes in iron-axial ligand bonds induced by allosteric transitions. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(19)84434-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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29
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31
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Paul J, Smith ML, Nordén B, Paul KG. Spin and electron distributions in heme-cyanide models and hemeproteins. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 832:265-73. [PMID: 4074748 DOI: 10.1016/0167-4838(85)90259-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Proton NMR spectra of low-spin Fe(III) cyanoprotoheme as prosthetic group in a number of proteins are presented. The diagonally positioned 1-, 5- and 3-, 8-methyl groups obey shifts proportional to the Fe(III)/(II) reduction potential Em7, which indicates a pseudo-contact interaction. The correlation with Em7 is understandable if one postulates an enhanced rhombic distortion, dominating the Fe-methyl dipolar interactions. Hartree-Fock-Slater quantum chemical calculations show no significant changes of spin density as a function of the Fe-L5 distance, except at the iron atom and predominantly in the 3dxz and 3dyz orbitals. 4p orbitals, on the other hand, uphold most of the changes of electron density. We also observe a principal difference in the amino acid sequences in the heme-accommodating pocket of oxygen carriers and two-electron transmitters.
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32
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Van Wart HE, Zimmer J. Resonance Raman evidence for the activation of dioxygen in horseradish oxyperoxidase. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)39483-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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33
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Spiro TG. Resonance Raman spectroscopy as a probe of heme protein structure and dynamics. ADVANCES IN PROTEIN CHEMISTRY 1985; 37:111-59. [PMID: 2998161 DOI: 10.1016/s0065-3233(08)60064-9] [Citation(s) in RCA: 104] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Our understanding of metalloporphyrin resonance Raman spectra has advanced to the point where it is possible to obtain detailed information about the structure of the heme group in situ in heme proteins. The porphyrin skeletal mode frequencies can be analyzed in terms of the ligation and spin state of the heme and may provide information about protein-induced stresses. The high-frequency region of the spectrum also contains bands due to vibrations of the porphyrin peripheral substituents, which are potentially monitors of the protein contacts. In the low-frequency region, it is possible to locate bands, at least in some states of the heme protein, which are associated with vibrations of the axial ligands. They give direct information about the nature of the bonding to exogenous ligands or to the proximal protein residue. Thus, a variety of evidence is potentially available in the resonance Raman spectra from which a fairly complete picture of the heme site can be assembled for a particular protein in its various functional states. Detailed studies have been pursued for paradigmatic heme proteins, including myoglobin, hemoglobin, cytochrome c, horseradish peroxidase, and cytochrome oxidase. These studies provide a substantial data base from which the exploration of lesser known systems can be launched. Another extension of current knowledge to new frontiers is in the time domain, since pulsed lasers now make it feasible to carry out time-resolved resonance Raman studies on heme protein reactions. Time-resolved resonance Raman spectroscopy is capable of elucidating the temporal evolution of heme structure and provides a link between heme chemistry and protein dynamics. This link is being elucidated for hemoglobin and cytochrome c, where specific heme intermediates have been identified following ligand photodissociation or electron transfer.
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34
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Kerr EA, Yu NT, Gersonde K. Assignment of the Fe-N epsilon (His) stretching mode in the resonance Raman spectra of a monomeric insect cyanomethaemoglobin. FEBS Lett 1984; 178:31-3. [PMID: 6500060 DOI: 10.1016/0014-5793(84)81233-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Resonance Raman (RR) spectra of the monomeric cyanomethaemoglobin CTT III from insect larvae of Chironomus thummi thummi are shown for the range of 200-550 cm-1. By iron and cyanide isotope exchange a line varying between 307 cm-1 for 57Fe-13C15N and 311 cm-1 for 54Fe-12C14N, has been assigned to the Fe-N epsilon stretching mode of this haem complex. The substitution of 54Fe for 57Fe has no effect on the Fe-C = N bending mode whereas it affects the Fe-CN stretching mode.
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35
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Yoshimura T, Ozaki T. Electronic spectra for nitrosyl(protoporphyrin IX dimethyl ester)iron(II) and its complexes with nitrogenous bases as model systems for nitrosylhemoproteins. Arch Biochem Biophys 1984; 229:126-35. [PMID: 6703691 DOI: 10.1016/0003-9861(84)90137-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Soret and visible absorption spectra for nitrosyl(protoporphyrin IX dimethyl ester)iron(II) (Fe(PPIXDME)(NO] and its complexes with nitrogenous bases (imidazoles, pyridines, aliphatic amines, and cyclic secondary amines) as model systems for nitrosylhemoproteins have been measured in various solvents. As the solvent polarity increases, the Soret and visible absorption bands for the five-coordinate Fe(PPIXDME) (NO) were shifted to shorter wavelengths. Accompanying the coordination of a nitrogenous base to the vacant axial position of Fe(PPIXDME)(NO), the Soret band becomes sharp and the band maximum is shifted to longer wavelengths. The band positions for the six-coordinate Fe(PPIXDME)(NO)(Base) complex are not sensitive to the pi-bonding ability of the axial ligand trans to NO group. The electronic spectra of five-coordinate Fe(PPIXDME)(NO) and six-coordinate Fe(PPIXDME)(NO)(Base) complexes are interpreted in relation to the structural information. The comparison of the spectra for model systems with those for nitrosylhemoproteins is discussed.
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36
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Benko B, Yu NT. Resonance Raman studies of nitric oxide binding to ferric and ferrous hemoproteins: detection of Fe(III)--NO stretching, Fe(III)--N--O bending, and Fe(II)--N--O bending vibrations. Proc Natl Acad Sci U S A 1983; 80:7042-6. [PMID: 6580627 PMCID: PMC390123 DOI: 10.1073/pnas.80.22.7042] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The nature of bonding interactions between Fe(III) and NO in the ferric nitrosyl complexes of myoglobin (Mb), hemoglobin A (HbA), and horseradish peroxidase (HRP) is investigated by Soret-excited resonance Raman spectroscopy. On the basis of 15NO and N18O isotope shifts, we clearly identified the Fe(III)--NO bond stretching frequencies at 595 cm-1 (ferric Mb X NO), 594 cm-1 (ferric HbA X NO), and 604 cm-1 (ferric HRP X NO). The Fe(III)--N--O bending vibrations are located at 573 cm-1 (ferric Mb X NO) and 574 cm-1 (ferric HRP X NO), which are very similar to the Fe(II)--C--O bending modes at 578 cm-1 in Mb X CO and HbA X CO. However, the Fe(III)--NO and Fe(II)--CO stretching frequencies differ by approximately equal to 90 cm-1, indicating a much stronger iron-axial ligand bond for the [Fe(III) + NO] system, which is isoelectronic with the [Fe(II) + CO] system and, hence, presumably also has a linear Fe(III)--N--O linkage (in the absence of distal steric effect). The unusually strong Fe(III)--NO bond may be attributed to the pi bonding involving the unpaired electron in the pi (NO) orbital. The N18O isotope shift data indicate that the widely accepted assignment of the Fe(II)--NO stretching vibration at approximately equal to 554 cm-1 in ferrous nitrosyl Mb/HbA is incorrect; instead, we assign it to the Fe(II)--N--O bending mode. The validity of the assignment of Fe(II)--O2 stretch at 567 cm-1 in oxy-HbA by Brunner [Brunner, H. (1974) Naturwissenschaften 61, 129-130] is now in doubt. Literature data are presented to suggest that it is the Fe(II)--O--O bending vibration.
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Mackin HC, Tsubaki M, Yu NT. Resonance Raman studies of Co-O2 and O-O stretching vibrations in oxy-cobalt hemes. Biophys J 1983; 41:349-57. [PMID: 6838973 PMCID: PMC1329188 DOI: 10.1016/s0006-3495(83)84446-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Strong evidence suggests that the stretching vibration of the bound oxygen can be perturbed by an accidentally degenerate porphyrin ring mode, resulting in two split frequencies. In the Co(II)(TpivPP) (pyridine) (18)O(2) complex, we demonstrate that the nu((18)O-(18)O) mode, after being shifted from its nu((16)O-(16)O) value at 1,156 cm(-1), undergoes a resonance interaction with the 1,080 cm(-1) porphyrin mode, giving rise to two lines at 1,067 and 1,089 cm(-1). In the O(2) complex of Co(II) mesoporphyrin IX-substituted sperm whale myoglobin, we observed a dramatic intensity increase at 1,132 cm(-1) upon (16)O(2) --> (18)O(2) substitution, which is due to the reappearance of the 1,132-cm(-1) porphyrin mode after the removal of resonance conditions. A decrease in O(2) binding affinity, caused by the proximal base tension, corresponds to an increase in the Co-O(2) stretching frequency. The nu(Co-O(2)) at 527 cm(-1) for the low affinity Co(II)(TpivPP)(1,2-Me(2)Im) O(2) complex is 11 cm(-1) higher than the 516-cm(-1) value for the high affinity complex (with N-MeIm replacing 1,2-Me(2)Im). However, in the corresponding iron complexes the reverse behavior is observed, i.e., the nu(Fe-O(2)) decreases for the (1,2-Me(2)Im) complex. There is a 24-cm(-1) difference in the Co-O(2) stretching frequencies between Co(II)(TpivPP)(N-MeIm)O(2) (at 516 cm(-1)) and oxy meso CoMb (at 540 cm(-1)), suggesting a protein induced distortion of the Co-O-O linkage. However, the values for nu(Fe-O(2)) are nearly identical between Fe(II)(TpivPP)(N-MeIm)O(2) (at 571 cm(-1)) and oxy Mb (at 573 cm(-1)), indicating that O(2) binds to myoglobin in the same manner as in the sterically unhindered "picket fence" complex. Evidence is presented that suggests the presence of two dioxygen stretching frequencies due to two different conformers in each of the N-MeIm and 1,2-Me(2)Im complex of oxy Co(II)(TpivPP).
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