1
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Aktar MS, de Serrano V, Ghiladi RA, Franzen S. Structural Comparison of Substrate Binding Sites in Dehaloperoxidase A and B. Biochemistry 2024; 63:1761-1773. [PMID: 38959050 DOI: 10.1021/acs.biochem.4c00179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Dehalperoxidase (DHP) has diverse catalytic activities depending on the substrate binding conformation, pH, and dynamics in the distal pocket above the heme. According to our hypothesis, the molecular structure of the substrate and binding orientation in DHP guide enzymatic function. Enzyme kinetic studies have shown that the catalytic activity of DHP B is significantly higher than that of DHP A despite 96% sequence homology. There are more than 30 substrate-bound structures with DHP B, each providing insight into the nature of enzymatic binding at the active site. By contrast, the only X-ray crystallographic structures of small molecules in a complex with DHP A are phenols. This study is focused on investigating substrate binding in DHP A to compare with DHP B structures. Fifteen substrates were selected that were known to bind to DHP B in the crystal to test whether soaking substrates into DHP A would yield similar structures. Five of these substrates yielded X-ray crystal structures of substrate-bound DHP A, namely, 2,4-dichlorophenol (1.48 Å, PDB: 8EJN), 2,4-dibromophenol (1.52 Å, PDB: 8VSK), 4-nitrophenol (2.03 Å, PDB: 8VKC), 4-nitrocatechol (1.40 Å, PDB: 8VKD), and 4-bromo-o-cresol (1.64 Å, PDB: 8VZR). For the remaining substrates that bind to DHP B, such as cresols, 5-bromoindole, benzimidazole, 4,4-biphenol, 4.4-ethylidenebisphenol, 2,4-dimethoxyphenol, and guaiacol, the electron density maps in DHP A are not sufficient to determine the presence of the substrates, much less their orientation. In our hands, only phenols, 4-Br-o-cresol, and 4-nitrocatechol can be soaked into crystalline DHP A. None of the larger substrates were observed to bind. A minimum of seven hanging drops were selected for soaking with more than 50 crystals screened for each substrate. The five high-quality examples of direct comparison of modes of binding in DHP A and B for the same substrate provide further support for the hypothesis that the substrate-binding conformation determines the enzyme function of DHP.
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Affiliation(s)
- Mst Sharmin Aktar
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Reza A Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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2
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González-Delgado JM, Thompson PM, Andrałojć W, Gdaniec Z, Ghiladi RA, Franzen S. Comparison of the Backbone Dynamics of Dehaloperoxidase-Hemoglobin Isoenzymes. J Phys Chem B 2024; 128:3383-3397. [PMID: 38563384 DOI: 10.1021/acs.jpcb.3c07176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Dehaloperoxidase (DHP) is a multifunctional hemeprotein with a functional switch generally regulated by the chemical class of the substrate. Its two isoforms, DHP-A and DHP-B, differ by only five amino acids and have an almost identical protein fold. However, the catalytic efficiency of DHP-B for oxidation by a peroxidase mechanism ranges from 2- to 6-fold greater than that of DHP-A depending on the conditions. X-ray crystallography has shown that many substrates and ligands have nearly identical binding in the two isoenzymes, suggesting that the difference in catalytic efficiency could be due to differences in the conformational dynamics. We compared the backbone dynamics of the DHP isoenzymes at pH 7 through heteronuclear relaxation dynamics at 11.75, 16.45, and 19.97 T in combination with four 300 ns MD simulations. While the overall dynamics of the isoenzymes are similar, there are specific local differences in functional regions of each protein. In DHP-A, Phe35 undergoes a slow chemical exchange between two conformational states likely coupled to a swinging motion of Tyr34. Moreover, Asn37 undergoes fast chemical exchange in DHP-A. Given that Phe35 and Asn37 are adjacent to Tyr34 and Tyr38, it is possible that their dynamics modulate the formation and migration of the active tyrosyl radicals in DHP-A at pH 7. Another significant difference is that both distal and proximal histidines have a 15-18% smaller S2 value in DHP-B, thus their greater flexibility could account for the higher catalytic activity. The distal histidine grants substrate access to the distal pocket. The greater flexibility of the proximal histidine could also accelerate H2O2 activation at the heme Fe by increased coupling of an amino acid charge relay to stabilize the ferryl Fe(IV) oxidation state in a Poulos-Kraut "push-pull"-type peroxidase mechanism.
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Affiliation(s)
| | - Peter M Thompson
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
- Molecular Education, Technology and Research Innovation Center (METRIC), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Witold Andrałojć
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland
| | - Zofia Gdaniec
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland
| | - Reza A Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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3
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Aktar MS, Hill R, Holbert W, Franzen S. Decomposition of 2,4-dihalophenols by dehaloperoxidase activity and spontaneous reaction with hydrogen peroxide. J Inorg Biochem 2024; 252:112473. [PMID: 38199051 DOI: 10.1016/j.jinorgbio.2023.112473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 12/08/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024]
Abstract
The enzyme dehaloperoxidase (DHP) found in the marine worm Amphitrite ornata is capable of enzymatic peroxidation of 2,4-dichlorophenol (DCP) and 2,4-dibromophenol (DBP). There is also at least one parallel oxidative pathway and the major products 2-chloro-1,4-benzoquinone (2-ClQ) and 2-bromo-1,4-benzoquinone (2-BrQ) undergo aspontaneous secondary hydroxylation reaction. The oxidation and hydroxylation reactions have been monitored by UV-visible spectroscopy, High Performance Liquid Chromatography (HPLC), and mass spectrometry. Evidence from time-resolved UV-visible spectroscopy suggests that the hydroxylations of 2-ClQ and 2-BrQ in the presence of hydrogen peroxide (H2O2) are non-enzymatic spontaneous processes approximately ∼10 and ∼ 5 times slower, respectively, than the enzymatic oxidation of DCP or DBP by DHP in identical solvent conditions. The products 2-ClQ and 2-BrQ have λmaxat 255 nm and 260 nm, respectively. Both substrates, DCP and DBP, react to form a parallel product peaked at 240 nm on the same time scale as the formation of 2-ClQ and 2-BrQ. The 240 nm band is not associated with the hydroxylation process, nor is it attributable to the catechol 3,5-dihalobenzene-1,3-diol observed by mass spectrometry. One possible explanation is that muconic acid is formed as a decomposition product, which could follow decomposition either the catechol or hydroxyquinone. These reactions give a more complete understanding of the biodegradation of xenobiotics by the multi-functional hemoglobin, DHP, in Amphitrite ornata. SYNOPSIS: The decomposition of 2,4-dihalophenols catalyzed by dehaloperoxidase was studied by UV-visible spectroscopy, High Performance Liquid Chromatography and Liquid Chromatography-Mass Spectrometry. Spectroscopic evidence suggests two major products, which we propose are 2-halo-1,4-benzoquinone and 2-halomuconic acid. These complementary techniques give a high-level view of the degradation of xenobiotics in marine ecosystems.
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Affiliation(s)
- Mst Sharmin Aktar
- Dept. of Chemistry, North Carolina State Univ., Raleigh, NC 27695-8204, United States of America
| | - Ransom Hill
- Dept. of Chemistry, North Carolina State Univ., Raleigh, NC 27695-8204, United States of America
| | - Wyatt Holbert
- Dept. of Chemistry, North Carolina State Univ., Raleigh, NC 27695-8204, United States of America
| | - Stefan Franzen
- Dept. of Chemistry, North Carolina State Univ., Raleigh, NC 27695-8204, United States of America.
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Aktar MS, de Serrano V, Ghiladi R, Franzen S. Comparative study of the binding and activation of 2,4-dichlorophenol by dehaloperoxidase A and B. J Inorg Biochem 2023; 247:112332. [PMID: 37480762 DOI: 10.1016/j.jinorgbio.2023.112332] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/11/2023] [Accepted: 07/14/2023] [Indexed: 07/24/2023]
Abstract
The dehaloperoxidase-hemoglobin (DHP), first isolated from the coelom of a marine terebellid polychaete, Amphitrite ornata, is an example of a multi-functional heme enzyme. Long known for its reversible oxygen (O2) binding, further studies have established DHP activity as a peroxidase, oxidase, oxygenase, and peroxygenase. The specific reactivity depends on substrate binding at various internal and external binding sites. This study focuses on comparison of the binding and reactivity of the substrate 2,4-dichlorophenol (DCP) in the isoforms DHPA and B. There is strong interest in the degradation of DCP because of its wide use in the chemical industry, presence in waste streams, and particular reactivity to form dioxins, some of the most toxic compounds known. The catalytic efficiency is 3.5 times higher for DCP oxidation in DHPB than DHPA by a peroxidase mechanism. However, DHPA and B both show self-inhibition even at modest concentrations of DCP. This phenomenon is analogous to the self-inhibition of 2,4,6-trichlorophenol (TCP) at higher concentration. The activation energies of the electron transfer steps in DCP in DHPA and DHPB are 19.3 ± 2.5 and 24.3 ± 3.2 kJ/mol, respectively, compared to 37.2 ± 6.5 kJ/mol in horseradish peroxidase (HRP), which may be a result of the more facile electron transfer of an internally bound substrate in DHPA. The x-ray crystal structure of DHPA bound with DCP determined at 1.48 Å resolution, shows tight substrate binding inside the heme pocket of DHPA (PDB 8EJN). This research contributes to the studies of DHP as a naturally occurring bioremediation enzyme capable of oxidizing a wide range of environmental pollutants.
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Affiliation(s)
- Mst Sharmin Aktar
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, United States of America
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, United States of America
| | - Reza Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, United States of America
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, United States of America.
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Zhang X, Liu Y. Direct Electrophilic Attack of Compound I on the Indole Ring in the Peroxygenase Mechanism of Dehaloperoxidase DHP B in Degrading Haloindole: Electron Transfer Promotes the Reaction. Inorg Chem 2023; 62:13230-13240. [PMID: 37561650 DOI: 10.1021/acs.inorgchem.3c01425] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
The H2O2-dependent degradation of haloindole catalyzed by the dehaloperoxidase (DHP) from Amphitrite ornate has been reported to employ the peroxygenase mechanism, and the two oxidized products 5-halo-2-oxindole and 5-halo-3-oxindole have a similar amount. According to a previous experimental study, compound I (Cpd I) was suggested to be responsible for triggering the reaction, and the reaction may undergo three possible intermediates; however, the reaction details are still unclear. To clarify the reaction mechanism of DHP, the computational model was constructed on the basis of the high-resolution crystal structure, and a series of the quantum mechanical/molecular mechanical calculations were performed. Based on our calculation results, it is confirmed that the reaction starts from the direct electrophilic attack of Cpd I on the indole ring of the substrate, and the resulted intermediate contains both a carbocation and an oxygen anion, whereas the common hydrogen abstraction by Cpd I was calculated to correspond to a relatively higher barrier. In addition, a net electron transfer from the substrate to the iron center is observed during the attack of Cpd I on the indole ring; therefore, the carbocation/oxygen anion intermediate can easily undergo an intramolecular hydride transfer to form the product 5-halo-2-oxindole or isomerize to the epoxide intermediate which finally generates another product 5-halo-3-oxindole. It is the zwitterionic characteristic of the intermediate that makes the intermolecular hydride transfer quite easy, and it is the high electron affinity of the iron center that promotes the single-electron oxidation of the reaction intermediate. Our calculations well explain the formation of two oxidized products 5-halo-2-oxindole and 5-halo-3-oxindole.
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Affiliation(s)
- Xianghui Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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6
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Madhuresh NKD, Nguyen H, Franzen S. The divergent pH dependence of substrate turnover in dehaloperoxidases A and B. J Inorg Biochem 2023; 238:112029. [PMID: 36371913 DOI: 10.1016/j.jinorgbio.2022.112029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/05/2022]
Abstract
The pH-dependent peroxidase activity in both dehaloperoxidases A and B was studied by a kinetic assay, stopped flow spectroscopy, resonance Raman spectroscopy, and high-performance liquid chromatography at pH 5.0, 6.0, and 7.0. At pH 7.0, both isozymes follow the peroxidase ping-pong kinetic model derived from the three-step reaction scheme using the steady-state approximation. However, deviation from standard saturation behavior is observed at pH < 6.0 and [TCP] > 0.7 mM, owing to multiple processes: a) self-inhibition of TCP by internal binding; b) oxidation of the product by a pH- and concentration-dependent secondary reaction; and c) formation of an inactive species known as compound RH in the absence of oxidizable substrate. Although DHP-A and DHP-B differ by only 5 amino acids, they show a complete trend reversal in their observed peroxidase kinetics and product yields. Although at pH 7.0 DHP-B had higher TCP oxidation activity than DHP-A as reported previously, as pH was lowered, DHP-A appeared to have a higher peroxidase activity than DHP-B. This is an unprecedented result. However, the fact that there are multiple processes contributing to both kinetics and yield of TCP oxidation complicates interpretation of these data. Deactivation via compound RH and self-inhibition are pH dependent reactions that compete with substrate oxidation. Compound RH formation was observed to be rapid at low pH. A complete set of control experiments were conducted to differentiate the various contributions to the observed enzyme kinetics.
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Affiliation(s)
| | - Hilbert Nguyen
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, United States of America
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, United States of America.
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7
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Yun D, de Serrano V, Ghiladi RA. Oxidation of bisphenol A (BPA) and related compounds by the multifunctional catalytic globin dehaloperoxidase. J Inorg Biochem 2023; 238:112020. [PMID: 36272837 DOI: 10.1016/j.jinorgbio.2022.112020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
Dehaloperoxidase (DHP) from the marine polychaete Amphitrite ornata is a multifunctional enzyme that possesses peroxidase, peroxygenase, oxidase and oxygenase activities. Herein, we investigated the reactivity of DHP B with bisphenol A (BPA) and related compounds (bisphenol E, bisphenol F, tetrachlorobisphenol A, 2,2'-biphenol, 3,3'-biphenol, 4,4'-biphenol, and 3,3'-dibromo-4,4'-biphenol). As a previously unknown substrate for DHP B, BPA (as a representative substrate) is an endocrine disruptor widely used in polycarbonate and epoxy resins, thus resulting in human exposure. Reactivity studies with these substrates were investigated using high performance liquid chromatography (HPLC), and their corresponding oxidation products were determined by mass spectrometry (GC-MS/ LC-MS). BPA undergoes oxidation in the presence of DHP B and hydrogen peroxide yielding two cleavage products (4-isopropenylphenol and 4-(2-hydroxypropan-2-yl)phenol), and oligomers with varying degrees of oxidation. 18O-labeling studies confirmed that the O-atom incorporated into the products was derived exclusively from water, consistent with substrate oxidation via a peroxidase-based mechanism. The X-ray crystal structures of DHP bound with bisphenol E (1.48 Å), bisphenol F (1.75 Å), 2,2'-biphenol (1.90 Å) and 3,3'-biphenol (1.30 Å) showed substrate binding sites are in the distal pocket of the heme cofactor, similar to other previously studied DHP substrates. Stopped-flow UV-visible spectroscopy was utilized to investigate the mechanistic details and enzyme oxidation states during substrate turnover, and a reaction mechanism is proposed. The data presented here strongly suggest that DHP B can catalyze the oxidation of bisphenols and biphenols, thus providing evidence of how infaunal invertebrates can contribute to the biotransformation of these marine pollutants.
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Affiliation(s)
- Dongju Yun
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, United States
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, United States
| | - Reza A Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, United States.
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8
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Malewschik T, Carey LM, de Serrano V, Ghiladi RA. Bridging the functional gap between reactivity and inhibition in dehaloperoxidase B from Amphitrite ornata: Mechanistic and structural studies with 2,4- and 2,6-dihalophenols. J Inorg Biochem 2022; 236:111944. [PMID: 35969974 DOI: 10.1016/j.jinorgbio.2022.111944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 06/29/2022] [Accepted: 07/20/2022] [Indexed: 12/15/2022]
Abstract
The multifunctional catalytic globin dehaloperoxidase (DHP) from the marine worm Amphitrite ornata was shown to catalyze the H2O2-dependent oxidation of 2,4- and 2,6-dihalophenols (DXP; X = F, Cl, Br). Product identification by LC-MS revealed multiple monomeric products with varying degrees of oxidation and/or dehalogenation, as well as oligomers with n up to 6. Mechanistic and 18O-labeling studies demonstrated sequential dihalophenol oxidation via peroxidase and peroxygenase activities. Binding studies established that 2,4-DXP (X = Cl, Br) have the highest affinities of any known DHP substrate. X-ray crystallography identified different binding positions for 2,4- and 2,6-DXP substrates in the hydrophobic distal pocket of DHP. Correlation between the number of halogens and the substrate binding orientation revealed a halogen-dependent binding motif for mono- (4-halophenol), di- (2,4- and 2,6-dihalophenol) and trihalophenols (2,4,6-trihalopenol). Taken together, the findings here on dihalophenol reactivity with DHP advance our understanding of how these compounds bridge the inhibitory and oxidative functions of their mono- and trihalophenol counterparts, respectively, and provide further insight into the protein structure-function paradigm relevant to multifunctional catalytic globins in comparison to their monofunctional analogs.
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Affiliation(s)
- Talita Malewschik
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, United States
| | - Leiah M Carey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, United States
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, United States
| | - Reza A Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, United States.
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9
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Moreno-Chicano T, Carey LM, Axford D, Beale JH, Doak RB, Duyvesteyn HME, Ebrahim A, Henning RW, Monteiro DCF, Myles DA, Owada S, Sherrell DA, Straw ML, Šrajer V, Sugimoto H, Tono K, Tosha T, Tews I, Trebbin M, Strange RW, Weiss KL, Worrall JAR, Meilleur F, Owen RL, Ghiladi RA, Hough MA. Complementarity of neutron, XFEL and synchrotron crystallography for defining the structures of metalloenzymes at room temperature. IUCRJ 2022; 9:610-624. [PMID: 36071813 PMCID: PMC9438502 DOI: 10.1107/s2052252522006418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Room-temperature macromolecular crystallography allows protein structures to be determined under close-to-physiological conditions, permits dynamic freedom in protein motions and enables time-resolved studies. In the case of metalloenzymes that are highly sensitive to radiation damage, such room-temperature experiments can present challenges, including increased rates of X-ray reduction of metal centres and site-specific radiation-damage artefacts, as well as in devising appropriate sample-delivery and data-collection methods. It can also be problematic to compare structures measured using different crystal sizes and light sources. In this study, structures of a multifunctional globin, dehaloperoxidase B (DHP-B), obtained using several methods of room-temperature crystallographic structure determination are described and compared. Here, data were measured from large single crystals and multiple microcrystals using neutrons, X-ray free-electron laser pulses, monochromatic synchrotron radiation and polychromatic (Laue) radiation light sources. These approaches span a range of 18 orders of magnitude in measurement time per diffraction pattern and four orders of magnitude in crystal volume. The first room-temperature neutron structures of DHP-B are also presented, allowing the explicit identification of the hydrogen positions. The neutron data proved to be complementary to the serial femtosecond crystallography data, with both methods providing structures free of the effects of X-ray radiation damage when compared with standard cryo-crystallography. Comparison of these room-temperature methods demonstrated the large differences in sample requirements, data-collection time and the potential for radiation damage between them. With regard to the structure and function of DHP-B, despite the results being partly limited by differences in the underlying structures, new information was gained on the protonation states of active-site residues which may guide future studies of DHP-B.
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Affiliation(s)
- Tadeo Moreno-Chicano
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Leiah M. Carey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | - Danny Axford
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - John H. Beale
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - R. Bruce Doak
- Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Helen M. E. Duyvesteyn
- Division of Structural Biology (STRUBI), University of Oxford, The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| | - Ali Ebrahim
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Robert W. Henning
- BioCARS, University of Chicago, Building 434B, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Diana C. F. Monteiro
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203-1102, USA
| | - Dean A. Myles
- Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Shigeki Owada
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Darren A. Sherrell
- Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Megan L. Straw
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Vukica Šrajer
- BioCARS, University of Chicago, Building 434B, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | | | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Takehiko Tosha
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Ivo Tews
- Biological Sciences, University of Southampton, University Road, Southampton SO17 1BJ, United Kingdom
| | - Martin Trebbin
- Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203-1102, USA
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14260, USA
| | - Richard W. Strange
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Kevin L. Weiss
- Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Jonathan A. R. Worrall
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Flora Meilleur
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
- Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Robin L. Owen
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Reza A. Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | - Michael A. Hough
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
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10
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Popescu C, Dinh T, Chen H, Miller D, Washburn A, McGuire A, Dumarieh R, D'Antonio J, Ghiladi RA. Mössbauer studies of the ferryl, ferrous and ferric states of dehaloperoxidase from A. ornata. J Inorg Biochem 2022; 234:111867. [DOI: 10.1016/j.jinorgbio.2022.111867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 04/13/2022] [Accepted: 05/17/2022] [Indexed: 10/18/2022]
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12
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Thompson MK, Shay MR, de Serrano V, Dumarieh R, Ghiladi RA, Franzen S. A new inhibition mechanism in the multifunctional catalytic hemoglobin dehaloperoxidase as revealed by the DHP A(V59W) mutant: A spectroscopic and crystallographic study. J PORPHYR PHTHALOCYA 2021. [DOI: 10.1142/s1088424621500826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
As multifunctional catalytic hemoglobins, dehaloperoxidase isoenzymes A and B (DHP A and B) are among the most versatile hemoproteins in terms of activities displayed. The ability of DHP to bind over twenty different substrates in the distal pocket might appear to resemble the promiscuousness of monooxygenase enzymes, yet there are identifiable substrate-specific interactions that can steer the type of oxidation (O-atom vs. electron transfer) that occurs inside the DHP distal pocket. Here, we have investigated the DHP A(V59W) mutant in order to probe the limits of conformational flexibility in the distal pocket as it relates to the genesis of this substrate-dependent activity differentiation. The X-ray crystal structure of the metaquo DHP A(V59W) mutant (PDB 3K3U) and the V59W mutant in complex with fluoride [denoted as DHP A(V59W-F)] (PDB 7MNH) show significant mobility of the tryptophan in the distal pocket, with two parallel conformations having W59-N[Formula: see text] H-bonded to a heme-bound ligand (H2O or F[Formula: see text], and another conformation [observed only in DHP A(V59W-F)] that brings W59 sufficiently close to the heme as to preclude axial ligand binding. UV-vis and resonance Raman spectroscopic studies show that DHP A(V59W) is 5-coordinate high spin (5cHS) at pH 5 and 6-coordinate high spin (6cHS) at pH 7, whereas DHP A(V59W-F) is 6cHS from pH 5 to 7. Enzyme assays confirm robust peroxidase activity at pH 5, but complete loss of activity at pH 7. We find no evidence that tryptophan plays a role in the oxidation mechanism ([Formula: see text]. radical formation). Instead, the data reveal a new mechanism of DHP inhibition, namely a shift towards a non-reactive form by OH[Formula: see text] ligation to the heme-Fe that is strongly stabilized (presumably through H-bonding interactions) by the presence of W59 in the distal cavity.
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Affiliation(s)
- Matthew K. Thompson
- Department of Chemistry & Biochemistry, University of Alabama, 250 Hackberry Lane, Tuscaloosa, AL 35487, USA
| | - Madeline R. Shay
- Department of Chemistry & Biochemistry, University of Alabama, 250 Hackberry Lane, Tuscaloosa, AL 35487, USA
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Rania Dumarieh
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Reza A. Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
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13
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Lin YW. Biodegradation of aromatic pollutants by metalloenzymes: A structural-functional-environmental perspective. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213774] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Abstract
Fluorochemicals are a widely distributed class of compounds and have been utilized across a wide range of industries for decades. Given the environmental toxicity and adverse health threats of some fluorochemicals, the development of new methods for their decomposition is significant to public health. However, the carbon-fluorine (C-F) bond is among the most chemically robust bonds; consequently, the degradation of fluorinated hydrocarbons is exceptionally difficult. Here, metalloenzymes that catalyze the cleavage of this chemically challenging bond are reviewed. These enzymes include histidine-ligated heme-dependent dehaloperoxidase and tyrosine hydroxylase, thiolate-ligated heme-dependent cytochrome P450, and four nonheme oxygenases, namely, tetrahydrobiopterin-dependent aromatic amino acid hydroxylase, 2-oxoglutarate-dependent hydroxylase, Rieske dioxygenase, and thiol dioxygenase. While much of the literature regarding the aforementioned enzymes highlights their ability to catalyze C-H bond activation and functionalization, in many cases, the C-F bond cleavage has been shown to occur on fluorinated substrates. A copper-dependent laccase-mediated system representing an unnatural radical defluorination approach is also described. Detailed discussions on the structure-function relationships and catalytic mechanisms provide insights into biocatalytic defluorination, which may inspire drug design considerations and environmental remediation of halogenated contaminants.
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Affiliation(s)
- Yifan Wang
- Department of Chemistry, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA.
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15
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Malewschik T, de Serrano V, McGuire AH, Ghiladi RA. The multifunctional globin dehaloperoxidase strikes again: Simultaneous peroxidase and peroxygenase mechanisms in the oxidation of EPA pollutants. Arch Biochem Biophys 2019; 673:108079. [PMID: 31445024 DOI: 10.1016/j.abb.2019.108079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 01/25/2023]
Abstract
The multifunctional catalytic hemoglobin dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata was found to catalyze the H2O2-dependent oxidation of EPA Priority Pollutants (4-Me-o-cresol, 4-Cl-m-cresol and pentachlorophenol) and EPA Toxic Substances Control Act compounds (o-, m-, p-cresol and 4-Cl-o-cresol). Biochemical assays (HPLC/LC-MS) indicated formation of multiple oxidation products, including the corresponding catechol, 2-methylbenzoquinone (2-MeBq), and oligomers with varying degrees of oxidation and/or dehalogenation. Using 4-Br-o-cresol as a representative substrate, labeling studies with 18O confirmed that the O-atom incorporated into the catechol was derived exclusively from H2O2, whereas the O-atom incorporated into 2-MeBq was from H2O, consistent with this single substrate being oxidized by both peroxygenase and peroxidase mechanisms, respectively. Stopped-flow UV-visible spectroscopic studies strongly implicate a role for Compound I in the peroxygenase mechanism leading to catechol formation, and for Compounds I and ES in the peroxidase mechanism that yields the 2-MeBq product. The X-ray crystal structures of DHP bound with 4-F-o-cresol (1.42 Å; PDB 6ONG), 4-Cl-o-cresol (1.50 Å; PDB 6ONK), 4-Br-o-cresol (1.70 Å; PDB 6ONX), 4-NO2-o-cresol (1.80 Å; PDB 6ONZ), o-cresol (1.60 Å; PDB 6OO1), p-cresol (2.10 Å; PDB 6OO6), 4-Me-o-cresol (1.35 Å; PDB 6ONR) and pentachlorophenol (1.80 Å; PDB 6OO8) revealed substrate binding sites in the distal pocket in close proximity to the heme cofactor, consistent with both oxidation mechanisms. The findings establish cresols as a new class of substrate for DHP, demonstrate that multiple oxidation mechanisms may exist for a given substrate, and provide further evidence that different substituents can serve as functional switches between the different activities performed by dehaloperoxidase. More broadly, the results demonstrate the complexities of marine pollution where both microbial and non-microbial systems may play significant roles in the biotransformations of EPA-classified pollutants, and further reinforces that heterocyclic compounds of anthropogenic origin should be considered as environmental stressors of infaunal organisms.
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Affiliation(s)
- Talita Malewschik
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695-8204, USA
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695-8204, USA
| | - Ashlyn H McGuire
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695-8204, USA
| | - Reza A Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695-8204, USA.
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16
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Lin Y. Rational design of heme enzymes for biodegradation of pollutants toward a green future. Biotechnol Appl Biochem 2019; 67:484-494. [DOI: 10.1002/bab.1788] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/06/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Ying‐Wu Lin
- School of Chemistry and Chemical Engineering University of South China Hengyang People's Republic of China
- Laboratory of Protein Structure and Function University of South China Hengyang People's Republic of China
- Hunan Key Laboratory for the Design and Application of Actinide Complexes University of South China Hengyang People's Republic of China
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17
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McGuire AH, Carey LM, de Serrano V, Dali S, Ghiladi RA. Peroxidase versus Peroxygenase Activity: Substrate Substituent Effects as Modulators of Enzyme Function in the Multifunctional Catalytic Globin Dehaloperoxidase. Biochemistry 2018; 57:4455-4468. [DOI: 10.1021/acs.biochem.8b00540] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Ashlyn H. McGuire
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Leiah M. Carey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Safaa Dali
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Reza A. Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
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18
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Carey LM, Gavenko R, Svistunenko DA, Ghiladi RA. How nature tunes isoenzyme activity in the multifunctional catalytic globin dehaloperoxidase from Amphitrite ornata. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:230-241. [DOI: 10.1016/j.bbapap.2017.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 11/05/2017] [Accepted: 11/07/2017] [Indexed: 01/29/2023]
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19
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Selective tuning of activity in a multifunctional enzyme as revealed in the F21W mutant of dehaloperoxidase B from Amphitrite ornata. J Biol Inorg Chem 2017; 23:209-219. [DOI: 10.1007/s00775-017-1520-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/17/2017] [Indexed: 11/25/2022]
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20
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Bindings of NO, CO, and O 2 to multifunctional globin type dehaloperoxidase follow the 'sliding scale rule'. Biochem J 2017; 474:3485-3498. [PMID: 28899945 DOI: 10.1042/bcj20170515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/06/2017] [Accepted: 09/12/2017] [Indexed: 01/09/2023]
Abstract
Dehaloperoxidase-hemoglobin (DHP), a multifunctional globin protein, not only functions as an oxygen carrier as typical globins such as myoglobin and hemoglobin, but also as a peroxidase, a mono- and dioxygenase, peroxygenase, and an oxidase. Kinetics of DHP binding to NO, CO, and O2 were characterized for wild-type DHP A and B and the H55D and H55V DHP A mutants using stopped-flow methods. All three gaseous ligands bind to DHP significantly more weakly than sperm whale myoglobin (SWMb). Both CO and NO bind to DHP in a one-step process to form a stable six-coordinate complex. Multiple-step NO binding is not observed in DHP, which is similar to observations in SWMb, but in contrast with many heme sensor proteins. The weak affinity of DHP for O2 is mainly due to a fast O2 dissociation rate, in accordance with a longer εN-Fe distance between the heme iron and distal histidine in DHP than that in Mb, and an open-distal pocket that permits ligand escape. Binding affinities in DHP show the same 3-4 orders separation between the pairs NO/CO and CO/O2, consistent with the 'sliding scale rule' hypothesis. Strong gaseous ligand discrimination by DHP is very different from that observed in typical peroxidases, which show poor gaseous ligand selectivity, correlating with a neutral proximal imidazole ligand rather than an imidazolate. The present study provides useful insights into the rationale for DHP to function both as mono-oxygenase and oxidase, and is the first example of a globin peroxidase shown to follow the 'sliding scale rule' hypothesis in gaseous ligand discrimination.
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21
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McCombs NL, Smirnova T, Ghiladi RA. Oxidation of Pyrrole by Dehaloperoxidase-Hemoglobin: Chemoenzymatic Synthesis of Pyrrolin-2-Ones. Catal Sci Technol 2017; 7:3104-3118. [PMID: 29158890 PMCID: PMC5693384 DOI: 10.1039/c7cy00781g] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The use of oxidoreductases as biocatalysts in the syntheses of functionalized, monomeric pyrroles has been a challenge owing to, among a number of factors, undesired polypyrrole formation. Here, we have investigated the ability of dehaloperoxidase (DHP), the coelomic hemoglobin from the terebellid polychaete Amphitrite ornata, to catalyze the H2O2-dependent oxidation of pyrroles as a new class of substrate for this enzyme. Substrate oxidation was observed for all compounds employed (pyrrole, N-methylpyrrole, 2-methylpyrrole, 3-methylpyrrole and 2,5-dimethylpyrrole) under both aerobic and anaerobic conditions. Using pyrrole as a representative substrate, only a single oxidation product, 4-pyrrolin-2-one, was observed, and notably without formation of polypyrrole. Reactivity could be initiated from all three biologically relevant oxidation states for this catalytic globin: ferric, ferrous and oxyferrous. Isotope labeling studies determined that the O-atom incorporated into the 4-pyrrolin-2-one product was derived exclusively from H2O2, indicative of a peroxygenase mechanism. Consistent with this observation, single- and double-mixing stopped-flow UV-visible spectroscopic studies supported Compound I, but not Compounds ES or II, as the catalytically-relevant ferryl intermediate involved in pyrrole oxidation. Electrophilic addition of the ferryl oxygen to pyrrole is proposed as the mechanism of O-atom transfer. The results demonstrate the breadth of chemical reactivity afforded by dehaloperoxidase, and provide further evidence for establishing DHP as a multifunctional globin with practical applications as a biocatalyst.
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Affiliation(s)
- Nikolette L McCombs
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204 USA. Tel: +1 919 513 0680
| | - Tatyana Smirnova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204 USA. Tel: +1 919 513 0680
| | - Reza A Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204 USA. Tel: +1 919 513 0680
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22
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Reeder BJ. Redox and Peroxidase Activities of the Hemoglobin Superfamily: Relevance to Health and Disease. Antioxid Redox Signal 2017; 26:763-776. [PMID: 27637274 DOI: 10.1089/ars.2016.6803] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
SIGNIFICANCE Erythrocyte hemoglobin (Hb) and myocyte myoglobin, although primarily oxygen-carrying proteins, have the capacity to do redox chemistry. Such redox activity in the wider family of globins now appears to have important associations with the mechanisms of cell stress response. In turn, an understanding of such mechanisms in vivo may have a potential in the understanding of cancer therapy resistance and neurodegenerative disorders such as Alzheimer's. Recent Advances: There has been an enhanced understanding of the redox chemistry of the globin superfamily in recent years, leading to advances in development of Hb-based blood substitutes and in hypotheses relating to specific disease mechanisms. Neuroglobin (Ngb) and cytoglobin (Cygb) have been linked to cell protection mechanisms against hypoxia and oxidative stress, with implications in the onset and progression of neurodegenerative diseases for Ngb and cancer for Cygb. CRITICAL ISSUES Despite advances in the understanding of redox chemistry of globins, the physiological roles of many of these proteins still remain ambiguous at best. Confusion over potential physiological roles may relate to multifunctional roles for globins, which may be modulated by surface-exposed cysteine pairs in some globins. Such roles may be critical in deciphering the relationships of these globins in human diseases. FUTURE DIRECTIONS Further studies are required to connect the considerable knowledge on the mechanisms of globin redox chemistry in vitro with the physiological and pathological roles of globins in vivo. In doing so, new therapies for neurodegenerative disorders and cancer therapy resistance may be targeted. Antioxid. Redox Signal. 26, 763-776.
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Affiliation(s)
- Brandon J Reeder
- School of Biological Sciences, University of Essex , Essex, United Kingdom
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23
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McCombs NL, Moreno-Chicano T, Carey LM, Franzen S, Hough MA, Ghiladi RA. Interaction of Azole-Based Environmental Pollutants with the Coelomic Hemoglobin from Amphitrite ornata: A Molecular Basis for Toxicity. Biochemistry 2017; 56:2294-2303. [PMID: 28387506 DOI: 10.1021/acs.biochem.7b00041] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The toxicities of azole pollutants that have widespread agricultural and industrial uses are either poorly understood or unknown, particularly with respect to how infaunal organisms are impacted by this class of persistent organic pollutant. To identify a molecular basis by which azole compounds may have unforeseen toxicity on marine annelids, we examine here their impact on the multifunctional dehaloperoxidase (DHP) hemoglobin from the terebellid polychaete Amphitrite ornata. Ultraviolet-visible and resonance Raman spectroscopic studies showed an increase in the six-coordinate low-spin heme population in DHP isoenzyme B upon binding of imidazole, benzotriazole, and benzimidazole (Kd values of 52, 82, and 110 μM, respectively), suggestive of their direct binding to the heme-Fe. Accordingly, atomic-resolution X-ray crystal structures, supported by computational studies, of the DHP B complexes of benzotriazole (1.14 Å), benzimidazole (1.08 Å), imidazole (1.08 Å), and indazole (1.12 Å) revealed two ligand binding motifs, one with direct ligand binding to the heme-Fe, and another in which the ligand binds in the hydrophobic distal pocket without coordinating the heme-Fe. Taken together, the results demonstrate a new mechanism by which azole pollutants can potentially disrupt hemoglobin function, thereby improving our understanding of their impact on infaunal organisms in marine and aquatic environments.
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Affiliation(s)
- Nikolette L McCombs
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
| | - Tadeo Moreno-Chicano
- School of Biological Sciences, University of Essex , Wivenhoe Park, Colchester, Essex CO4 3SQ, U.K
| | - Leiah M Carey
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
| | - Michael A Hough
- School of Biological Sciences, University of Essex , Wivenhoe Park, Colchester, Essex CO4 3SQ, U.K
| | - Reza A Ghiladi
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
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24
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Streit BR, Celis AI, Shisler K, Rodgers KR, Lukat-Rodgers GS, DuBois JL. Reactions of Ferrous Coproheme Decarboxylase (HemQ) with O 2 and H 2O 2 Yield Ferric Heme b. Biochemistry 2016; 56:189-201. [PMID: 27982566 DOI: 10.1021/acs.biochem.6b00958] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A recently discovered pathway for the biosynthesis of heme b ends in an unusual reaction catalyzed by coproheme decarboxylase (HemQ), where the Fe(II)-containing coproheme acts as both substrate and cofactor. Because both O2 and H2O2 are available as cellular oxidants, pathways for the reaction involving either can be proposed. Analysis of reaction kinetics and products showed that, under aerobic conditions, the ferrous coproheme-decarboxylase complex is rapidly and selectively oxidized by O2 to the ferric state. The subsequent second-order reaction between the ferric complex and H2O2 is slow, pH-dependent, and further decelerated by D2O2 (average kinetic isotope effect of 2.2). The observation of rapid reactivity with peracetic acid suggested the possible involvement of Compound I (ferryl porphyrin cation radical), consistent with coproheme and harderoheme reduction potentials in the range of heme proteins that heterolytically cleave H2O2. Resonance Raman spectroscopy nonetheless indicated a remarkably weak Fe-His interaction; how the active site structure may support heterolytic H2O2 cleavage is therefore unclear. From a cellular perspective, the use of H2O2 as an oxidant in a catalase-positive organism is intriguing, as is the unusual generation of heme b in the Fe(III) rather than Fe(II) state as the end product of heme synthesis.
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Affiliation(s)
- Bennett R Streit
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59715, United States
| | - Arianna I Celis
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59715, United States
| | - Krista Shisler
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59715, United States
| | - Kenton R Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University , Fargo, North Dakota 58102, United States
| | - Gudrun S Lukat-Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University , Fargo, North Dakota 58102, United States
| | - Jennifer L DuBois
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59715, United States
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25
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McCombs NL, D’Antonio J, Barrios DA, Carey LM, Ghiladi RA. Nonmicrobial Nitrophenol Degradation via Peroxygenase Activity of Dehaloperoxidase-Hemoglobin from Amphitrite ornata. Biochemistry 2016; 55:2465-78. [DOI: 10.1021/acs.biochem.6b00143] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikolette L. McCombs
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204
| | - Jennifer D’Antonio
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204
| | - David A. Barrios
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204
| | - Leiah M. Carey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204
| | - Reza A. Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204
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26
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Zhao J, Moretto J, Le P, Franzen S. Measurement of Internal Substrate Binding in Dehaloperoxidase–Hemoglobin by Competition with the Heme–Fluoride Binding Equilibrium. J Phys Chem B 2015; 119:2827-38. [DOI: 10.1021/jp512996v] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Jing Zhao
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Justin Moretto
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Peter Le
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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27
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Le P, Zhao J, Franzen S. Correlation of Heme Binding Affinity and Enzyme Kinetics of Dehaloperoxidase. Biochemistry 2014; 53:6863-77. [DOI: 10.1021/bi5005975] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter Le
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jing Zhao
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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28
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Barrios DA, D'Antonio J, McCombs NL, Zhao J, Franzen S, Schmidt AC, Sombers LA, Ghiladi RA. Peroxygenase and oxidase activities of dehaloperoxidase-hemoglobin from Amphitrite ornata. J Am Chem Soc 2014; 136:7914-25. [PMID: 24791647 PMCID: PMC4063182 DOI: 10.1021/ja500293c] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
![]()
The marine globin dehaloperoxidase-hemoglobin
(DHP) from Amphitrite ornata was found to catalyze
the H2O2-dependent oxidation of monohaloindoles,
a previously
unknown class of substrate for DHP. Using 5-Br-indole as a representative
substrate, the major monooxygenated products were found to be 5-Br-2-oxindole
and 5-Br-3-oxindolenine. Isotope labeling studies confirmed that the
oxygen atom incorporated was derived exclusively from H2O2, indicative of a previously unreported peroxygenase
activity for DHP. Peroxygenase activity could be initiated from either
the ferric or oxyferrous states with equivalent substrate conversion
and product distribution. It was found that 5-Br-3-oxindole, a precursor
of the product 5-Br-3-oxindolenine, readily reduced the ferric enzyme
to the oxyferrous state, demonstrating an unusual product-driven reduction
of the enzyme. As such, DHP returns to the globin-active oxyferrous
form after peroxygenase activity ceases. Reactivity with 5-Br-3-oxindole
in the absence of H2O2 also yielded 5,5′-Br2-indigo above the expected reaction stoichiometry under aerobic
conditions, and O2-concentration studies demonstrated dioxygen
consumption. Nonenzymatic and anaerobic controls both confirmed the
requirements for DHP and molecular oxygen in the catalytic generation
of 5,5′-Br2-indigo, and together suggest a newly
identified oxidase activity for DHP.
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Affiliation(s)
- David A Barrios
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
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29
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Khoshtariya DE, Dolidze TD, Shushanyan M, van Eldik R. Long-range electron transfer with myoglobin immobilized at Au/mixed-SAM junctions: mechanistic impact of the strong protein confinement. J Phys Chem B 2014; 118:692-706. [PMID: 24369906 DOI: 10.1021/jp4101569] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Horse muscle myoglobin (Mb) was tightly immobilized at Au-deposited ~15-Å-thick mixed-type (1:1) alkanethiol SAMs, HS-(CH₂)₁₁-COOH/HS-(CH₂)₁₁-OH, and placed in contact with buffered H₂O or D₂O solutions. Fast-scan cyclic voltammetry (CV) and a Marcus-equation-based analysis were applied to determine unimolecular standard rate constants and reorganization free energies for electron transfer (ET), under variable-temperature (15-55 °C) and -pressure (0.01-150 MPa) conditions. The CV signal was surprisingly stable and reproducible even after multiple temperature and pressure cycles. The data analysis revealed the following values: standard rate constant, 33 s⁻¹ (25 °C, 0.01 MPa, H₂O); reorganization free energy, 0.5 ± 0.1 eV (throughout); activation enthalpy, 12 ± 3 kJ mol⁻¹; activation volume, -3.1 ± 0.2 cm³ mol⁻¹; and pH-dependent solvent kinetic isotope effect (k(H)⁰/k(D)⁰), 0.7-1.4. Furthermore, the values for the rate constant and reorganization free energy are very similar to those previously found for cytochrome c electrostatically immobilized at the monocomponent Au/HS-(CH₂)₁₁-COOH junction. In vivo, Mb apparently forms a natural electrostatic complex with cytochrome b₅ (cyt-b₅) through the "dynamic" (loose) docking pattern, allowing for a slow ET that is intrinsically coupled to the water's removal from the "defective" heme iron (altogether shaping the biological repair mechanism for Mb's "met" form). In contrary, our experiments rather mimic the case of a "simple" (tight) docking of the redesigned (mutant) Mb with cyt-b₅ (Nocek et al. J. Am. Chem. Soc. 2010, 132, 6165-6175). According to our analysis, in this configuration, Mb's distal pocket (linked to the "ligand channel") seems to be arrested within the restricted configuration, allowing the rate-determining reversible ET process to be coupled only to the inner-sphere reorganization (minimal elongation/shortening of an Fe-OH₂ bond) rather than the pronounced detachment (rebinding) of water and, hence, to be much faster.
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Affiliation(s)
- Dimitri E Khoshtariya
- Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg , 91058 Erlangen, Germany
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30
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Zhao J, Zhao J, Franzen S. The Regulatory Implications of Hydroquinone for the Multifunctional Enzyme Dehaloperoxidase-Hemoglobin from Amphitrite ornata. J Phys Chem B 2013; 117:14615-24. [DOI: 10.1021/jp407663n] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Jing Zhao
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Junjie Zhao
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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31
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Dumarieh R, D'Antonio J, Deliz-Liang A, Smirnova T, Svistunenko DA, Ghiladi RA. Tyrosyl radicals in dehaloperoxidase: how nature deals with evolving an oxygen-binding globin to a biologically relevant peroxidase. J Biol Chem 2013; 288:33470-82. [PMID: 24100039 DOI: 10.1074/jbc.m113.496497] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dehaloperoxidase (DHP) from Amphitrite ornata, having been shown to catalyze the hydrogen peroxide-dependent oxidation of trihalophenols to dihaloquinones, is the first oxygen binding globin that possesses a biologically relevant peroxidase activity. The catalytically competent species in DHP appears to be Compound ES, a reactive intermediate that contains both a ferryl heme and a tyrosyl radical. By simulating the EPR spectra of DHP activated by H2O2, Thompson et al. (Thompson, M. K., Franzen, S., Ghiladi, R. A., Reeder, B. J., and Svistunenko, D. A. (2010) J. Am. Chem. Soc. 132, 17501-17510) proposed that two different radicals, depending on the pH, are formed, one located on either Tyr-34 or Tyr-28 and the other on Tyr-38. To provide additional support for these simulation-based assignments and to deduce the role(s) that tyrosyl radicals play in DHP, stopped-flow UV-visible and rapid-freeze-quench EPR spectroscopic methods were employed to study radical formation in DHP when three tyrosine residues, Tyr-28, Tyr-34, and Tyr-38, were replaced either individually or in combination with phenylalanines. The results indicate that radicals form on all three tyrosines in DHP. Evidence for the formation of DHP Compound I in several tyrosine mutants was obtained. Variants that formed Compound I showed an increase in the catalytic rate for substrate oxidation but also an increase in heme bleaching, suggesting that the tyrosines are necessary for protecting the enzyme from oxidizing itself. This protective role of tyrosines is likely an evolutionary adaptation allowing DHP to avoid self-inflicted damage in the oxidative environment.
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Affiliation(s)
- Rania Dumarieh
- From the Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204 and
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32
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The role of T56 in controlling the flexibility of the distal histidine in dehaloperoxidase-hemoglobin from Amphitrite ornata. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2020-9. [DOI: 10.1016/j.bbapap.2013.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 06/07/2013] [Accepted: 06/10/2013] [Indexed: 11/23/2022]
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33
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Wang C, Lovelace LL, Sun S, Dawson JH, Lebioda L. Complexes of Dual-Function Hemoglobin/Dehaloperoxidase with Substrate 2,4,6-Trichlorophenol Are Inhibitory and Indicate Binding of Halophenol to Compound I. Biochemistry 2013; 52:6203-10. [DOI: 10.1021/bi400627w] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chunxue Wang
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Leslie L. Lovelace
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Shengfang Sun
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - John H. Dawson
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- School
of Medicine, University of South Carolina, Columbia, South Carolina 29209, United States
| | - Lukasz Lebioda
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- Center
for Colon Cancer Research, University of South Carolina, Columbia, South Carolina 29209, United States
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34
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Zhao J, Franzen S. Kinetic Study of the Inhibition Mechanism of Dehaloperoxidase-Hemoglobin A by 4-Bromophenol. J Phys Chem B 2013; 117:8301-9. [DOI: 10.1021/jp3116353] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jing Zhao
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
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35
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Plummer A, Thompson MK, Franzen S. Role of Polarity of the Distal Pocket in the Control of Inhibitor Binding in Dehaloperoxidase-Hemoglobin. Biochemistry 2013; 52:2218-27. [DOI: 10.1021/bi301509r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ashlee Plummer
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina
27695, United States
| | - Matthew K. Thompson
- Department
of Biochemistry, Vanderbilt University Medical Center, Nashville, Tennessee
37232, United States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina
27695, United States
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36
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Zhao J, de Serrano V, Dumarieh R, Thompson M, Ghiladi RA, Franzen S. The Role of the Distal Histidine in H2O2 Activation and Heme Protection in both Peroxidase and Globin Functions. J Phys Chem B 2012; 116:12065-77. [DOI: 10.1021/jp300014b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Junjie Zhao
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
| | - Rania Dumarieh
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
| | - Matt Thompson
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
| | - Reza A. Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
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37
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Franzen S, Thompson MK, Ghiladi RA. The dehaloperoxidase paradox. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:578-88. [DOI: 10.1016/j.bbapap.2011.12.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 12/20/2011] [Accepted: 12/23/2011] [Indexed: 12/01/2022]
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38
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Study of the electrostatic effects of mutations on the surface of dehaloperoxidase-hemoglobin A. Biochem Biophys Res Commun 2012; 420:733-7. [DOI: 10.1016/j.bbrc.2012.03.053] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 03/12/2012] [Indexed: 11/17/2022]
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39
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D’Antonio EL, Bowden EF, Franzen S. Thin-layer spectroelectrochemistry of the Fe(III)/Fe(II) redox reaction of dehaloperoxidase-hemoglobin. J Electroanal Chem (Lausanne) 2012. [DOI: 10.1016/j.jelechem.2011.12.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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40
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Franzen S, Sasan K, Sturgeon BE, Lyon BJ, Battenburg BJ, Gracz H, Dumariah R, Ghiladi R. Nonphotochemical Base-Catalyzed Hydroxylation of 2,6-Dichloroquinone by H2O2 Occurs by a Radical Mechanism. J Phys Chem B 2012; 116:1666-76. [DOI: 10.1021/jp208536x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Bradley E. Sturgeon
- Department of Chemistry, Monmouth College, Monmouth, Illinois 61462, United States
| | - Blake J. Lyon
- Department of Chemistry, Monmouth College, Monmouth, Illinois 61462, United States
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41
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D'Antonio EL, D'Antonio J, de Serrano V, Gracz H, Thompson MK, Ghiladi RA, Bowden EF, Franzen S. Functional consequences of the creation of an Asp-His-Fe triad in a 3/3 globin. Biochemistry 2011; 50:9664-80. [PMID: 21950839 DOI: 10.1021/bi201368u] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The proximal side of dehaloperoxidase-hemoglobin A (DHP A) from Amphitrite ornata has been modified via site-directed mutagenesis of methionine 86 into aspartate (M86D) to introduce an Asp-His-Fe triad charge relay. X-ray crystallographic structure determination of the metcyano forms of M86D [Protein Data Bank (PDB) entry 3MYN ] and M86E (PDB entry 3MYM ) mutants reveal the structural origins of a stable catalytic triad in DHP A. A decrease in the rate of H(2)O(2) activation as well as a lowered reduction potential versus that of the wild-type enzyme was observed in M86D. One possible explanation for the significantly lower activity is an increased affinity for the distal histidine in binding to the heme Fe to form a bis-histidine adduct. Resonance Raman spectroscopy demonstrates a pH-dependent ligation by the distal histidine in M86D, which is indicative of an increased trans effect. At pH 5.0, the heme Fe is five-coordinate, and this structure resembles the wild-type DHP A resting state. However, at pH 7.0, the distal histidine appears to form a six-coordinate ferric bis-histidine (hemichrome) adduct. These observations can be explained by the effect of the increased positive charge on the heme Fe on the formation of a six-coordinate low-spin adduct, which inhibits the ligation and activation of H(2)O(2) as required for peroxidase activity. The results suggest that the proximal charge relay in peroxidases regulate the redox potential of the heme Fe but that the trans effect is a carefully balanced property that can both activate H(2)O(2) and attract ligation by the distal histidine. To understand the balance of forces that modulate peroxidase reactivity, we studied three M86 mutants, M86A, M86D, and M86E, by spectroelectrochemistry and nuclear magnetic resonance spectroscopy of (13)C- and (15)N-labeled cyanide adducts as probes of the redox potential and of the trans effect in the heme Fe, both of which can be correlated with the proximity of negative charge to the N(δ) hydrogen of the proximal histidine, consistent with an Asp-His-Fe charge relay observed in heme peroxidases.
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Affiliation(s)
- Edward L D'Antonio
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
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42
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Du J, Huang X, Sun S, Wang C, Lebioda L, Dawson JH. Amphitrite ornata dehaloperoxidase (DHP): investigations of structural factors that influence the mechanism of halophenol dehalogenation using "peroxidase-like" myoglobin mutants and "myoglobin-like" DHP mutants. Biochemistry 2011; 50:8172-80. [PMID: 21800850 DOI: 10.1021/bi2009129] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dehaloperoxidase (DHP), discovered in the marine terebellid polychaete Amphitrite ornata, is the first heme-containing globin with a peroxidase activity. The sequence and crystal structure of DHP argue that it evolved from an ancient O(2) transport and storage globin. Thus, DHP retains an oxygen carrier function but also has the ability to degrade halophenol toxicants in its living environment. Sperm whale myoglobin (Mb) in the ferric state has a peroxidase activity ∼10 times lower than that of DHP. The catalytic activity enhancement observed in DHP appears to have been generated mainly by subtle changes in the positions of the proximal and distal histidine residues that appeared during DHP evolution. Herein, we report investigations into the mechanism of action of DHP derived from examination of "peroxidase-like" Mb mutants and "Mb-like" DHP mutants. The dehalogenation ability of wild-type Mb is augmented in the peroxidase-like Mb mutants (F43H/H64L, G65T, and G65I Mb) but attenuated in the Mb-like T56G DHP variant. X-ray crystallographic data show that the distal His residues in G65T Mb and G65I are positioned ∼0.3 and ∼0.8 Å, respectively, farther from the heme iron compared to that in the wild-type protein. The H93K/T95H double mutant Mb with the proximal His shifted to the "DHP-like" position has an increased peroxidase activity. In addition, a better dehaloperoxidase (M86E DHP) was generated by introducing a negative charge near His89 to enhance the imidazolate character of the proximal His. Finally, only minimal differences in dehalogenation activities are seen among the exogenous ligand-free DHP, the acetate-bound DHP, and the distal site blocker L100F DHP mutant. Thus, we conclude that binding of halophenols in the internal binding site (i.e., distal cavity) is not essential for catalysis. This work provides a foundation for a new structure-function paradigm for peroxidases and for the molecular evolution of the dual-function enzyme DHP.
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Affiliation(s)
- Jing Du
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 20208, USA
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43
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D'Antonio J, Ghiladi RA. Reactivity of deoxy- and oxyferrous dehaloperoxidase B from Amphitrite ornata: identification of compound II and its ferrous-hydroperoxide precursor. Biochemistry 2011; 50:5999-6011. [PMID: 21619067 DOI: 10.1021/bi200311u] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata is a bifunctional enzyme that possesses both hemoglobin and peroxidase activities. The bifunctional nature of DHP as a globin peroxidase appears to be at odds with the traditional starting oxidation state for each individual activity. Namely, reversible oxygen binding is only mediated via a ferrous heme in globins, and peroxidase activity is initiated from ferric centers and to the exclusion of the oxyferrous oxidation state from the peroxidase cycle. Thus, to address what appears to be a paradox, herein we report the details of our investigations into the DHP catalytic cycle when initiated from the deoxy- and oxyferrous states using biochemical assays, stopped-flow UV-visible, and rapid-freeze-quench electron paramagnetic resonance spectroscopies, and anaerobic methods. We demonstrate the formation of Compound II directly from deoxyferrous DHP B upon its reaction with hydrogen peroxide and show that this occurs both in the presence and in the absence of trihalophenol. Prior to the formation of Compound II, we have identified a new species that we have preliminarily attributed to a ferrous-hydroperoxide precursor that undergoes heterolysis to generate the aforementioned ferryl intermediate. Taken together, the results demonstrate that the oxyferrous state in DHP is a peroxidase competent starting species, and an updated catalytic cycle for DHP is proposed in which the ferric oxidation state is not an obligatory starting point for the peroxidase catalytic cycle of dehaloperoxidase. The data presented herein provide a link between the peroxidase and oxygen transport activities, which furthers our understanding of how this bifunctional enzyme is able to unite its two inherent functions in one system.
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Affiliation(s)
- Jennifer D'Antonio
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA
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44
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Nicoletti FP, Thompson MK, Franzen S, Smulevich G. Degradation of sulfide by dehaloperoxidase-hemoglobin from Amphitrite ornata. J Biol Inorg Chem 2011; 16:611-9. [DOI: 10.1007/s00775-011-0762-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 01/26/2011] [Indexed: 10/18/2022]
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45
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Davydov R, Osborne RL, Shanmugam M, Du J, Dawson JH, Hoffman BM. Probing the oxyferrous and catalytically active ferryl states of Amphitrite ornata dehaloperoxidase by cryoreduction and EPR/ENDOR spectroscopy. Detection of compound I. J Am Chem Soc 2010; 132:14995-5004. [PMID: 20925340 PMCID: PMC2978736 DOI: 10.1021/ja1059747] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dehaloperoxidase (DHP) from Amphitrite ornata is a heme protein that can function both as a hemoglobin and as a peroxidase. This report describes the use of 77 K cryoreduction EPR/ENDOR techniques to study both functions of DHP. Cryoreduced oxyferrous [Fe(II)-O(2)] DHP exhibits two EPR signals characteristic of a peroxoferric [Fe(III)-O(2)(2-)] heme species, reflecting the presence of conformational substates in the oxyferrous precursor. (1)H ENDOR spectroscopy of the cryogenerated substates shows that H-bonding interactions between His N(ε)H and heme-bound O(2) in these conformers are similar to those in the β-chain of oxyferrous hemoglobin A (HbA) and oxyferrous myoglobin, respectively. Decay of cryogenerated peroxoferric heme DHP intermediates upon annealing at temperatures above 180 K is accompanied by the appearance of a new paramagnetic species with an axial EPR signal with g(⊥) = 3.75 and g(∥) = 1.96, characteristic of an S = 3/2 spin state. This species is assigned to Compound I (Cpd I), in which a porphyrin π-cation radical is ferromagnetically coupled with an S = 1 ferryl [Fe(IV)═O] ion. This species was also trapped by rapid freeze-quench of the ambient-temperature reaction mixture of ferric [Fe(III)] DHP and H(2)O(2). However, in the latter case Cpd I is reduced very rapidly by a nearby tyrosine to form Cpd ES [(Fe(IV)═O)(porphyrin)/Tyr(•)]. Addition of the substrate analogue 2,4,6-trifluorophenol (F(3)PhOH) suppresses formation of the Cpd I intermediate during annealing of cryoreduced oxyferrous DHP at 190 K but has no effect on the spectroscopic properties of the remaining cryoreduced oxyferrous DHP intermediates and kinetics of their decay. These observations indicate that substrate (i) binds to oxyferrous DHP outside of the distal pocket and (ii) can reduce Cpd I to Cpd II [Fe(IV)═O]. These assumptions are also supported by the observation that F(3)PhOH has only a small effect on the EPR properties of radiolytically cryooxidized and cryoreduced ferrous [Fe(II)] DHP. EPR spectra of cryoreduced ferrous DHP disclose the multiconformational nature of the ferrous DHP precursor. The observation and characterization of Cpds I, II, and ES in the absence and in the presence of F(3)PhOH provides definitive evidence of a mechanism involving consecutive one-electron steps and clarifies the role of all intermediates formed during turnover.
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Affiliation(s)
- Roman Davydov
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Robert L. Osborne
- Department of Chemistry and Biochemistry University of South Carolina, Columbia, South Carolina 29208
| | | | - Jing Du
- Department of Chemistry and Biochemistry University of South Carolina, Columbia, South Carolina 29208
| | - John H. Dawson
- Department of Chemistry and Biochemistry University of South Carolina, Columbia, South Carolina 29208
- School of Medicine University of South Carolina, Columbia, South Carolina 29208
| | - Brian M. Hoffman
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208
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46
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Ma H, Thompson MK, Gaff J, Franzen S. Kinetic Analysis of a Naturally Occurring Bioremediation Enzyme: Dehaloperoxidase-Hemoglobin from Amphitrite ornata. J Phys Chem B 2010; 114:13823-9. [DOI: 10.1021/jp1014516] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Huan Ma
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, and Department of Chemistry, Zhejiang University, Hangzhou, China
| | - Matthew K. Thompson
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, and Department of Chemistry, Zhejiang University, Hangzhou, China
| | - John Gaff
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, and Department of Chemistry, Zhejiang University, Hangzhou, China
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, and Department of Chemistry, Zhejiang University, Hangzhou, China
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