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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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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, 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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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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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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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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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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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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Dynamics of dehaloperoxidase-hemoglobin A derived from NMR relaxation spectroscopy and molecular dynamics simulation. J Inorg Biochem 2018; 181:65-73. [DOI: 10.1016/j.jinorgbio.2018.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 12/11/2017] [Accepted: 01/07/2018] [Indexed: 11/18/2022]
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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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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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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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14
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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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15
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Zhao J, Lu C, Franzen S. Distinct Enzyme–Substrate Interactions Revealed by Two Dimensional Kinetic Comparison between Dehaloperoxidase-Hemoglobin and Horseradish Peroxidase. J Phys Chem B 2015; 119:12828-37. [DOI: 10.1021/acs.jpcb.5b07126] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jing Zhao
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Chang Lu
- Department
of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Stefan Franzen
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department
of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
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16
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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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17
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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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18
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Sun S, Sono M, Du J, Dawson JH. Evidence of the Direct Involvement of the Substrate TCP Radical in Functional Switching from Oxyferrous O2 Carrier to Ferric Peroxidase in the Dual-Function Hemoglobin/Dehaloperoxidase from Amphitrite ornata. Biochemistry 2014; 53:4956-69. [DOI: 10.1021/bi5002757] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shengfang Sun
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Masanori Sono
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Jing Du
- 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 29208, United States
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19
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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
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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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20
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Zhao J, de Serrano V, Franzen S. A model for the flexibility of the distal histidine in dehaloperoxidase-hemoglobin A based on X-ray crystal structures of the carbon monoxide adduct. Biochemistry 2014; 53:2474-82. [PMID: 24670063 PMCID: PMC4203366 DOI: 10.1021/bi5001905] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Dehaloperoxidase
hemoglobin A (DHP A) is a multifunctional hemoglobin
that appears to have evolved oxidative pathways for the degradation
of xenobiotics as a protective function that complements the oxygen
transport function. DHP A possesses at least two internal binding
sites, one for substrates and one for inhibitors, which include various
halogenated phenols and indoles. Herein, we report the X-ray crystallographic
structure of the carbonmonoxy complex (DHPCO). Unlike other DHP structures
with 6-coordinated heme, the conformation of the distal histidine
(H55) in DHPCO is primarily external or solvent exposed, despite the
fact that the heme Fe is 6-coordinated. As observed generally in globins,
DHP exhibits two distal histidine conformations (one internal and
one external). In previous structural studies, we have shown that
the distribution of H55 conformations is weighted strongly toward
the external position when the DHP heme Fe is 5-coordinated. The large
population of the external conformation of the distal histidine observed
in DHPCO crystals at pH 6.0 indicates that some structural factor
in DHP must account for the difference from other globins, which exhibit
a significant external conformation only when pH < 4.5. While the
original hypothesis suggested that interaction with a heme-Fe-bound
ligand was the determinant of H55 conformation, the current study
forces a refinement of that hypothesis. The external or open conformation
of H55 is observed to have interactions with two propionate groups
in heme, at distances of 3.82 and 2.73 Å, respectively. A relatively
weak hydrogen bonding interaction between H55 and CO, combined with
strong interactions with heme propionate (position 6), is hypothesized
to strengthen the external conformation of H55. Density function theory
(DFT) calculations were conducted to test whether there is a weaker
hydrogen bond interaction between H55 and heme bonded CO or O2. Molecular dynamics simulations were conducted to examine
how the tautomeric forms of H55 affect the dynamic motions of the
distal histidine that govern the switching between open and closed
conformations. The calculations support the modified hypothesis suggesting
a competition between the strength of interactions with heme ligand
and the heme propionates as the factors that determine the conformation
of the distal histidine.
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Affiliation(s)
- Junjie Zhao
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695, United States
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21
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Sun S, Sono M, Wang C, Du J, Lebioda L, Dawson JH. Influence of heme environment structure on dioxygen affinity for the dual function Amphitrite ornata hemoglobin/dehaloperoxidase. Insights into the evolutional structure-function adaptations. Arch Biochem Biophys 2014; 545:108-15. [PMID: 24440609 DOI: 10.1016/j.abb.2014.01.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/08/2014] [Accepted: 01/10/2014] [Indexed: 11/28/2022]
Abstract
Sea worm, Amphitrite ornata, has evolved its globin (an O(2) carrier) also to serves as a dehaloperoxidase (DHP) to detoxify haloaromatic pollutants generated by competing species. A previous mutagenesis study by our groups on both DHP and sperm whale myoglobin (SW Mb) revealed some structural factors that influence the dehaloperoxidase activities (significantly lower for Mb) of both proteins. Using an isocyanide/O(2) partition constant measurement method in this study, we have examined the effects of these structural factors on the O(2) equilibrium constants (KO2) of DHP, SW Mb, and their mutants. A clear trend of decreasing O(2) affinity and increasing catalytic activity along with the increase in the distal His N(ε)-heme iron distance is observed. An H93K/T95H Mb double mutant mimicking the DHP proximal His positioning exhibited markedly enhanced O(2) affinity, confirming the essential effect of proximal His rotation on the globin function of DHP. For DHP, the L100F, T56G and M86E variants showed the effects of distal volume, distal His flexibility and proximal electronic push, respectively, on the O(2) affinity. This study provides insights into how DHP has evolved its heme environment to gain significantly enhanced peroxidase capability without compromising its primary function as an O(2) carrier.
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Affiliation(s)
- Shengfang Sun
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States
| | - Masanori Sono
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States.
| | - Chunxue Wang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States
| | - Jing Du
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States
| | - Lukasz Lebioda
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States.
| | - John H Dawson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States; School of Medicine, University of South Carolina, United States.
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22
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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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23
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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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24
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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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25
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Zhao J, de Serrano V, Zhao J, Le P, Franzen S. Structural and Kinetic Study of an Internal Substrate Binding Site in Dehaloperoxidase-Hemoglobin A from Amphitrite ornata. Biochemistry 2013; 52:2427-39. [DOI: 10.1021/bi301307f] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jing 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
| | - Junjie Zhao
- 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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26
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Schkolnik G, Utesch T, Zhao J, Jiang S, Thompson MK, Mroginski MA, Hildebrandt P, Franzen S. Catalytic efficiency of dehaloperoxidase A is controlled by electrostatics – application of the vibrational Stark effect to understand enzyme kinetics. Biochem Biophys Res Commun 2013; 430:1011-5. [DOI: 10.1016/j.bbrc.2012.12.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 12/10/2012] [Indexed: 11/17/2022]
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27
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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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28
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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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29
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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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30
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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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31
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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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32
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Thompson MK, Franzen S, Davis MF, Oliver RC, Krueger JK. Dehaloperoxidase-hemoglobin from Amphitrite ornata is primarily a monomer in solution. J Phys Chem B 2011; 115:4266-72. [PMID: 21417234 DOI: 10.1021/jp201156r] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The crystal structures of the dehaloperoxidase-hemoglobin from A. ornata (DHP A) each report a crystallographic dimer in the unit cell. Yet, the largest dimer interface observed is 450 Å(2), an area significantly smaller than the typical value of 1200-2000 Å(2) and in contrast to the extensive interface region of other known dimeric hemoglobins. To examine the oligomerization state of DHP A in solution, we used gel permeation by fast protein liquid chromatography and small-angle X-ray scattering (SAXS). Gel permeation experiments demonstrate that DHP A elutes as a monomer (15.5 kDa) and can be separated from green fluorescent protein, which has a molar mass of 27 kDa, near the 31 kDa expected for the DHP A dimer. By SAXS, we found that DHP A is primarily monomeric in solution, but with a detectable level of dimer (~10%), under all conditions studied up to a protein concentration of 3.0 mM. These concentrations are likely 10-100-fold lower than the K(d) for dimer formation. Additionally, there was no significant effect either on the overall conformation of DHP A or its monomer-dimer equilibrium upon addition of the DHP A inhibitor, 4-iodophenol.
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Affiliation(s)
- Matthew K Thompson
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, USA
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33
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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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34
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Thompson MK, Davis MF, de Serrano V, Nicoletti FP, Howes BD, Smulevich G, Franzen S. Internal binding of halogenated phenols in dehaloperoxidase-hemoglobin inhibits peroxidase function. Biophys J 2010; 99:1586-95. [PMID: 20816071 DOI: 10.1016/j.bpj.2010.05.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 05/11/2010] [Accepted: 05/17/2010] [Indexed: 10/19/2022] Open
Abstract
Dehaloperoxidase (DHP) from the annelid Amphitrite ornata is a catalytically active hemoglobin-peroxidase that possesses a unique internal binding cavity in the distal pocket above the heme. The previously published crystal structure of DHP shows 4-iodophenol bound internally. This led to the proposal that the internal binding site is the active site for phenol oxidation. However, the native substrate for DHP is 2,4,6-tribromophenol, and all attempts to bind 2,4,6-tribromophenol in the internal site under physiological conditions have failed. Herein, we show that the binding of 4-halophenols in the internal pocket inhibits enzymatic function. Furthermore, we demonstrate that DHP has a unique two-site competitive binding mechanism in which the internal and external binding sites communicate through two conformations of the distal histidine of the enzyme, resulting in nonclassical competitive inhibition. The same distal histidine conformations involved in DHP function regulate oxygen binding and release during transport and storage by hemoglobins and myoglobins. This work provides further support for the hypothesis that DHP possesses an external binding site for substrate oxidation, as is typical for the peroxidase family of enzymes.
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Affiliation(s)
- Matthew K Thompson
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, USA
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35
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D'Antonio J, D'Antonio EL, Thompson MK, Bowden EF, Franzen S, Smirnova T, Ghiladi RA. Spectroscopic and mechanistic investigations of dehaloperoxidase B from Amphitrite ornata. Biochemistry 2010; 49:6600-16. [PMID: 20545299 DOI: 10.1021/bi100407v] [Citation(s) in RCA: 44] [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. Of the two DHP isoenzymes identified to date, much of the recent focus has been on DHP A, whereas very little is known pertaining to the activity, substrate specificity, mechanism of function, or spectroscopic properties of DHP B. Herein, we report the recombinant expression and purification of DHP B, as well as the details of our investigations into its catalytic cycle using biochemical assays, stopped-flow UV-visible, resonance Raman, and rapid freeze-quench electron paramagnetic resonance spectroscopies, and spectroelectrochemistry. Our experimental design reveals mechanistic insights and kinetic descriptions of the dehaloperoxidase mechanism which have not been previously reported for isoenzyme A. Namely, we demonstrate a novel reaction pathway in which the products of the oxidative dehalogenation of trihalophenols (dihaloquinones) are themselves capable of inducing formation of oxyferrous DHP B, and an updated catalytic cycle for DHP is proposed. We further demonstrate that, unlike the traditional monofunctional peroxidases, the oxyferrous state in DHP is a peroxidase-competent starting species, which suggests that the ferric oxidation state may not be an obligatory starting point for the enzyme. 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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Du J, Sono M, Dawson JH. Functional Switching of Amphitrite ornata Dehaloperoxidase from O2-Binding Globin to Peroxidase Enzyme Facilitated by Halophenol Substrate and H2O2. Biochemistry 2010; 49:6064-9. [DOI: 10.1021/bi100741z] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jing Du
- Department of Chemistry and Biochemistry
| | | | - John H. Dawson
- Department of Chemistry and Biochemistry
- School of Medicine
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de Serrano V, D'Antonio J, Franzen S, Ghiladi RA. Structure of dehaloperoxidase B at 1.58 A resolution and structural characterization of the AB dimer from Amphitrite ornata. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:529-38. [PMID: 20445228 PMCID: PMC2865366 DOI: 10.1107/s0907444910004580] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Accepted: 02/08/2010] [Indexed: 11/10/2022]
Abstract
As members of the globin superfamily, dehaloperoxidase (DHP) isoenzymes A and B from the marine annelid Amphitrite ornata possess hemoglobin function, but they also exhibit a biologically relevant peroxidase activity that is capable of converting 2,4,6-trihalophenols to the corresponding 2,6-dihaloquinones in the presence of hydrogen peroxide. Here, a comprehensive structural study of recombinant DHP B, both by itself and cocrystallized with isoenzyme A, using X-ray diffraction is presented. The structure of DHP B refined to 1.58 A resolution exhibits the same distal histidine (His55) conformational flexibility as that observed in isoenzyme A, as well as additional changes to the distal and proximal hydrogen-bonding networks. Furthermore, preliminary characterization of the DHP AB heterodimer is presented, which exhibits differences in the AB interface that are not observed in the A-only or B-only homodimers. These structural investigations of DHP B provide insights that may relate to the mechanistic details of the H(2)O(2)-dependent oxidative dehalogenation reaction catalyzed by dehaloperoxidase, present a clearer description of the function of specific residues in DHP at the molecular level and lead to a better understanding of the paradigms of globin structure-function relationships.
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Davis MF, Bobay BG, Franzen S. Determination of separate inhibitor and substrate binding sites in the dehaloperoxidase-hemoglobin from Amphitrite ornata. Biochemistry 2010; 49:1199-206. [PMID: 20067301 DOI: 10.1021/bi9018576] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dehaloperoxidase-hemoglobin (DHP A) is a dual function protein found in the terrebellid polychaete Amphitrite ornata. A. ornata is an annelid, which inhabits estuary mudflats with other polychaetes that secrete a range of toxic brominated phenols. DHP A is capable of binding and oxidatively dehalogenating some of these compounds. DHP A possesses the ability to bind halophenols in a distinct, internal distal binding pocket. Since its discovery, the distal binding pocket has been reported as the sole binding location for halophenols; however, data herein suggest a distinction between inhibitor (monohalogenated phenol) and substrate (trihalogenated phenol) binding locations. Backbone (13)Calpha, (13)Cbeta, carbonyl (13)C, amide (1)H, and amide (15)N resonance assignments have been made, and various halophenols were titrated into the protein. (1)H-(15)N HSQC experiments were collected at stoichiometric intervals during each titration, and binding locations specific for mono- and trihalogenated phenols have been identified. Titration of monohalogenated phenol induced primary changes around the distal binding pocket, while introduction of trihalogenated phenols created alterations of the distal histidine and the local area surrounding W120, a structural region that corresponds to a possible dimer interface region recently observed in X-ray crystal structures of DHP A.
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Affiliation(s)
- Michael F Davis
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27606, USA
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Feducia J, Dumarieh R, Gilvey LBG, Smirnova T, Franzen S, Ghiladi RA. Characterization of dehaloperoxidase compound ES and its reactivity with trihalophenols. Biochemistry 2009; 48:995-1005. [PMID: 19187035 DOI: 10.1021/bi801916j] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dehaloperoxidase (DHP), the oxygen transport hemoglobin from the terebellid polychaete Amphitrite ornata, is the first globin identified to possess a biologically relevant peroxidase activity. DHP has been shown to oxidize trihalophenols to dihaloquinones in a dehalogenation reaction that uses hydrogen peroxide as a substrate. Herein, we demonstrate that the first detectable intermediate following the addition of hydrogen peroxide to ferric DHP contains both a ferryl heme and a tyrosyl radical, analogous to Compound ES of cytochrome c peroxidase. Furthermore, we provide a detailed kinetic description for the reaction of preformed DHP Compound ES with the substrate 2,4,6-trichlorophenol and demonstrate the catalytic competency of this intermediate in generating the product 2,4-dichloroquinone. Using rapid-freeze-quench electron paramagnetic resonance spectroscopy, we detected a g approximately 2.0058 signal confirming the presence of a protein radical in DHP Compound ES. In the absence of substrate, DHP Compound ES evolves to a new species, Compound RH, which is functionally unique to dehaloperoxidase. We propose that this intermediate plays a protective role against heme bleaching. While unreactive toward further oxidation, Compound RH can be reduced and subsequently bind dioxygen, generating oxyferrous DHP, which may represent the catalytic link between peroxidase and oxygen transport activities in this bifunctional protein.
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Affiliation(s)
- Jeremiah Feducia
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, USA
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Davis MF, Gracz H, Vendeix FAP, de Serrano V, Somasundaram A, Decatur SM, Franzen S. Different Modes of Binding of Mono-, Di-, and Trihalogenated Phenols to the Hemoglobin Dehaloperoxidase from Amphitrite ornata. Biochemistry 2009; 48:2164-72. [DOI: 10.1021/bi801568s] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael F. Davis
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27606, Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27606, and Chemistry Department, Oberlin College, Oberlin, Ohio 44074
| | - Hanna Gracz
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27606, Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27606, and Chemistry Department, Oberlin College, Oberlin, Ohio 44074
| | - Franck A. P. Vendeix
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27606, Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27606, and Chemistry Department, Oberlin College, Oberlin, Ohio 44074
| | - Vesna de Serrano
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27606, Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27606, and Chemistry Department, Oberlin College, Oberlin, Ohio 44074
| | - Aswin Somasundaram
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27606, Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27606, and Chemistry Department, Oberlin College, Oberlin, Ohio 44074
| | - Sean M. Decatur
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27606, Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27606, and Chemistry Department, Oberlin College, Oberlin, Ohio 44074
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27606, Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27606, and Chemistry Department, Oberlin College, Oberlin, Ohio 44074
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41
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Smirnova TI, Weber RT, Davis MF, Franzen S. Substrate binding triggers a switch in the iron coordination in dehaloperoxidase from Amphitrite ornata: HYSCORE experiments. J Am Chem Soc 2008; 130:2128-9. [PMID: 18217756 DOI: 10.1021/ja0772952] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tatyana I Smirnova
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, USA.
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43
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Bailly X, Chabasse C, Hourdez S, Dewilde S, Martial S, Moens L, Zal F. Globin gene family evolution and functional diversification in annelids. FEBS J 2007; 274:2641-52. [PMID: 17451435 DOI: 10.1111/j.1742-4658.2007.05799.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Globins are the most common type of oxygen-binding protein in annelids. In this paper, we show that circulating intracellular globin (Alvinella pompejana and Glycera dibranchiata), noncirculating intracellular globin (Arenicola marina myoglobin) and extracellular globin from various annelids share a similar gene structure, with two conserved introns at canonical positions B12.2 and G7.0. Despite sequence divergence between intracellular and extracellular globins, these data strongly suggest that these three globin types are derived from a common ancestral globin-like gene and evolved by duplication events leading to diversification of globin types and derived functions. A phylogenetic analysis shows a distinct evolutionary history of annelid extracellular hemoglobins with respect to intracellular annelid hemoglobins and mollusc and arthropod extracellular hemoglobins. In addition, dehaloperoxidase (DHP) from the annelid, Amphitrite ornata, surprisingly exhibits close phylogenetic relationships to some annelid intracellular globins. We have characterized the gene structure of A. ornata DHP to confirm assumptions about its homology with globins. It appears that it has the same intron position as in globin genes, suggesting a common ancestry with globins. In A. ornata, DHP may be a derived globin with an unusual enzymatic function.
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Affiliation(s)
- Xavier Bailly
- Equipe Ecophysiologie: Adaptation et Evolution Moléculaires, UPMC, CNRS UMR 7144, Station Biologique, BP 74, Roscoff, France
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44
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Franzen S, Gilvey LB, Belyea JL. The pH dependence of the activity of dehaloperoxidase from Amphitrite ornata. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1774:121-30. [PMID: 17182294 DOI: 10.1016/j.bbapap.2006.09.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Revised: 09/18/2006] [Accepted: 09/29/2006] [Indexed: 11/17/2022]
Abstract
Dehaloperoxidase (DHP) from the terebellid polychaete, Amphitrite ornata, is the first hemoglobin that has peroxidase activity as part of its native function. The substrate 2,4,6-tribromophenol (TBP) is oxidatively debrominated by DHP to form 2,6-dibromoquinone (DBQ) in a two-electron process. There is a well-defined internal binding site for TBP above the heme, a feature not observed in other hemoglobins or peroxidases. A study of the pH dependence of the activity of DHP reveals a substantial difference in mechanism. From direct observation of the Soret band of the heme it is shown that the pKa for heme activation in protein DHP is 6.5. Below this pH the heme absorbance decreases in the presence of H2O2 with or without addition of substrate. The low pH data are consistent with significant heme degradation. Above pH 6.5 addition of H2O2 causes the heme to shift rapidly to a compound II spectrum and then slowly to an unidentified intermediate with an absorbance of 410 nm. However, the pKa of the substrate TBP is 6.8 and the greatest enzyme activity is observed above the pKa of TBP under conditions where the substrate is a phenolate anion (TPBO-). Although the mechanisms may differ, the data show that both neutral TBP and anionic TPBO- are converted to the quinone product. The mechanistic implications of the pH dependence are discussed by comparison other known peroxidases, which oxidize substrates at the heme edge.
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Affiliation(s)
- Stefan Franzen
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA.
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45
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46
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Abstract
Hemoglobin (Hb) occurs in all the kingdoms of living organisms. Its distribution is episodic among the nonvertebrate groups in contrast to vertebrates. Nonvertebrate Hbs range from single-chain globins found in bacteria, algae, protozoa, and plants to large, multisubunit, multidomain Hbs found in nematodes, molluscs and crustaceans, and the giant annelid and vestimentiferan Hbs comprised of globin and nonglobin subunits. Chimeric hemoglobins have been found recently in bacteria and fungi. Hb occurs intracellularly in specific tissues and in circulating red blood cells (RBCs) and freely dissolved in various body fluids. In addition to transporting and storing O(2) and facilitating its diffusion, several novel Hb functions have emerged, including control of nitric oxide (NO) levels in microorganisms, use of NO to control the level of O(2) in nematodes, binding and transport of sulfide in endosymbiont-harboring species and protection against sulfide, scavenging of O(2 )in symbiotic leguminous plants, O(2 )sensing in bacteria and archaebacteria, and dehaloperoxidase activity useful in detoxification of chlorinated materials. This review focuses on the extensive variation in the functional properties of nonvertebrate Hbs, their O(2 )binding affinities, their homotropic interactions (cooperativity), and the sensitivities of these parameters to temperature and heterotropic effectors such as protons and cations. Whenever possible, it attempts to relate the ligand binding properties to the known molecular structures. The divergent and convergent evolutionary trends evident in the structures and functions of nonvertebrate Hbs appear to be adaptive in extending the inhabitable environment available to Hb-containing organisms.
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Affiliation(s)
- R E Weber
- Danish Centre for Respiratory Adaptation, Department of Zoophysiology, Institute of Biology, University of Aarhus, Aarhus, Denmark.
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LaCount MW, Zhang E, Chen YP, Han K, Whitton MM, Lincoln DE, Woodin SA, Lebioda L. The crystal structure and amino acid sequence of dehaloperoxidase from Amphitrite ornata indicate common ancestry with globins. J Biol Chem 2000; 275:18712-6. [PMID: 10751397 DOI: 10.1074/jbc.m001194200] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The full-length, protein coding sequence for dehaloperoxidase was obtained using a reverse genetic approach and a cDNA library from marine worm Amphitrite ornata. The crystal structure of the dehaloperoxidase (DHP) was determined by the multiple isomorphous replacement method and was refined at 1.8-A resolution. The enzyme fold is that of the globin family and, together with the amino acid sequence information, indicates that the enzyme evolved from an ancient oxygen carrier. The peroxidase activity of DHP arose mainly through changes in the positions of the proximal and distal histidines relative to those seen in globins. The structure of a complex of DHP with 4-iodophenol is also reported, and it shows that in contrast to larger heme peroxidases DHP binds organic substrates in the distal cavity. The binding is facilitated by the histidine swinging in and out of the cavity. The modeled position of the oxygen atom bound to the heme suggests that the enzymatic reaction proceeds via direct attack of the oxygen atom on the carbon atom bound to the halogen atom.
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Affiliation(s)
- M W LaCount
- Departments of Chemistry and Biochemistry and Biological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA
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48
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Hourdez S, Lallier FH, De Cian MC, Green BN, Weber RE, Toulmond A. Gas transfer system in Alvinella pompejana (Annelida polychaeta, Terebellida): functional properties of intracellular and extracellular hemoglobins. Physiol Biochem Zool 2000; 73:365-73. [PMID: 10893176 DOI: 10.1086/316755] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2000] [Indexed: 11/03/2022]
Abstract
Alvinella pompejana is a tubicolous polychaete that dwells in the hottest part of the hydrothermal vent ecosystem in a highly variable mixture of vent (350 degrees C, anoxic, CO(2)- and sulfide-rich) and deep-sea (2 degrees C, mildly hypoxic) waters. This species has developed distinct-and specifically respiratory-adaptations to this challenging environment. An internal gas exchange system has recently been described, along with the report of an intracellular coelomic hemoglobin, in addition to the previously known extracellular vascular hemoglobin. This article reports the structure of coelomic hemoglobin and the functional properties of both hemoglobins in order to assess possible oxygen transfer. Coelomocytes contain a unique monomeric hemoglobin with a molecular weight of 14,810+/-1.5 Da, as determined by mass spectrometry. The functional properties of both hemoglobins are unexpectedly very similar under the same conditions of pH (6.1-8.2) and temperature (10 degrees -40 degrees C). The oxygen affinity of both proteins is relatively high (P50=0.66 Torr at 20 degrees C and pH 7), which facilitates oxygen uptake from the hypoxic environment. A strong Bohr effect (Phi ranging from -0.8 to -1.0) allows the release of oxygen to acidic tissues. Such similar properties imply a possible bidirectional transfer of oxygen between the two hemoglobins in the perioesophagal pouch, a mechanism that could moderate environmental variations of oxygen concentration and maintain brain oxygenation.
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Affiliation(s)
- S Hourdez
- Station Biologique de Roscoff, UPMC-Centre National de la Recherche Scientifique-INSU, BP 74, 29682 Roscoff Cedex, France.
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Teske JG, Edmonds CG, Deckert G, Satterlee JD. Structural features of Glycera dibranchiata monomer hemoglobins. Primary sequences of monomer hemoglobin components II and III. JOURNAL OF PROTEIN CHEMISTRY 1997; 16:139-50. [PMID: 9112607 DOI: 10.1023/a:1026346202134] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Primary sequences for the remaining two members (GMH2, GMH3) of the group of three major monomeric hemoglobins from the marine annelid Glycera dibranchiata have been obtained. Full sequences of each 147-amino acid globin were achieved with a high degree of confidence using standard Edman technology in combination with molecular mass determinations of the intact globins and of the cyanogen bromide cleavage fragments using electrospray ionization mass spectrometry. When minor assumptions concerning Q/E identities are made these new results indicate the likely correspondence of GMG2 with the protein represented by the first Glycera dibranchiata monomer hemoglobin complete sequence [Imamura et al., (1972), J. Biol. Chem. 247, 2785-2797]. When these new sequences are combined with the previously determined primary sequence for the third major monomer hemoglobin, GMH4 [Alam et al., J. Protein Chem. (1994), 13, 151-164], it becomes clear that these three (GMG2-4) are truly distinct proteins, contrary to previous suggestions. Surprisingly, our results show that none of these three primary sequences is identical to the published sequence of the refined monomer hemoglobin crystal structure protein; however, there is a strong correspondence to the GMG2 sequence. The present sequencing results, in combination with the published GMH4 sequence, confirm the presence of a distal Leu in place of the more commonly encountered distal His in all three of the major monomer hemoglobins isolated in this laboratory and indicate that the unusual B10 Phe occurs only in GMH4. Analysis of the sequences presented here, along with comparison of amino acid content for Glycera dibranchiata monomer hemoglobins isolated from three different laboratories, and comparison of NMR results from two laboratories suggest further correspondence which unify disparate published isolations.
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Affiliation(s)
- J G Teske
- Department of Chemistry, Washington State University, Pullman, 99164-4630, USA
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50
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Hannan F, Hall LM. Muscarinic acetylcholine receptors in invertebrates: comparisons with homologous receptors from vertebrates. EXS 1993; 63:98-145. [PMID: 8422542 DOI: 10.1007/978-3-0348-7265-2_6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The pharmacology, physiology and molecular biology of invertebrate muscarinic acetylcholine receptors are compared with current knowledge concerning vertebrate muscarinic acetylcholine receptors. Evidence for the existence of multiple receptor subtypes in invertebrates is examined, emphasizing what is presently known about the sensitivity of invertebrate preparations to subtype selective ligands previously defined in vertebrate studies. Other evidence for muscarinic receptor subtypes which is examined includes: heterogeneous responses to classical muscarinic ligands and evidence for coupling of invertebrate muscarinic receptors to several different classes of second messenger systems. Clues regarding possible functions for invertebrate muscarinic receptors are discussed, including evidence from both physiological studies and in situ localization studies which reveal patterns of receptor protein and mRNA expression. A detailed analysis of the structural similarities between a cloned Drosophila muscarinic receptor and vertebrate muscarinic receptors is also presented. Regions of the receptors that may be involved in ligand binding, effector coupling and receptor regulation are identified in this comparison. Future directions for invertebrate muscarinic receptor research are considered including: methods for cloning other receptor subtypes, methods for cloning homologous receptors from other species and genetic approaches for determining the physiological roles of muscarinic receptors.
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Affiliation(s)
- F Hannan
- State University of New York, School of Pharmacy, Department of Biochemical Pharmacology, Buffalo 14260
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