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Chen Y, Zhang J, Lu J, Shi H, Lan P, Wang W, Ma G, Wei X, Wang X, Yu H. Computational simulations uncover enantioselective metabolism of chiral triazole fungicides by human CYP450 enzymes: A case study of tebuconazole. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 284:116865. [PMID: 39137461 DOI: 10.1016/j.ecoenv.2024.116865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 07/19/2024] [Accepted: 08/09/2024] [Indexed: 08/15/2024]
Abstract
Tebuconazole (TEB), a prominent chiral triazole fungicide, has been extensively utilized for plant pathogen control globally. Despite experimental evidence of TEB metabolism in mammals, the enantioselectivity in the biotransformation of R- and S-TEB enantiomers by specific CYP450s remains elusive. In this work, integrated in silico simulations were employed to unveil the binding interactions and enantioselective metabolic fate of TEB enantiomers within human CYP1A2, 2B6, 2E1, and 3A4. Molecular dynamics (MD) simulations clearly delineated the binding specificity of R- and S-TEB to the four CYP450s, crucially determining their differences in metabolic activity and enantioselectivity. The primary driving force for robust ligand binding was identified as van der Waals interactions with CYP450s, particularly involving the hydrophobic residues. Mechanistic insights derived from quantum mechanics/molecular mechanics (QM/MM) calculations established C2-methyl hydroxylation as the predominant route of R-/S-TEB metabolism, while C6-hydroxylation and triazol epoxidation were deemed kinetically infeasible pathways. Specifically, the resulting hydroxy-R-TEB metabolite primarily originates from R-TEB biotransformation by 1A2, 2E1 and 3A4, whereas hydroxy-S-TEB is preferentially produced by 2B6. These findings significantly contribute to our comprehension of the binding specificity and enantioselective metabolic fate of chiral TEB by CYP450s, potentially informing further research on human health risk assessment associated with TEB exposure.
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Affiliation(s)
- Yewen Chen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Jing Zhang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Jiayu Lu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Huifang Shi
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Pengfei Lan
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Wei Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Guangcai Ma
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
| | - Xiaoxuan Wei
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Xueyu Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
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2
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McFarlane NR, Gui J, Oláh J, Harvey JN. Gaseous inhibition of the transsulfuration pathway by cystathionine β-synthase. Phys Chem Chem Phys 2024; 26:16579-16588. [PMID: 38832404 DOI: 10.1039/d4cp01321b] [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: 06/05/2024]
Abstract
The transsulfuration pathway plays a key role in mammals for maintaining the balance between cysteine and homocysteine, whose concentrations are critical in several biochemical processes. Human cystathionine β-synthase is a heme-containing, pyridoxal 5'-phosphate (PLP)-dependent enzyme found in this pathway. The heme group does not participate directly in catalysis, but has a regulatory function, whereby CO or NO binding inhibits the PLP-dependent reactions. In this study, we explore the detailed structural changes responsible for inhibition using quantum chemical calculations to validate the experimentally observed bonding patterns associated with heme CO and NO binding and molecular dynamics simulations to explore the medium-range structural changes triggered by gas binding and propagating to the PLP active site, which is more than 20 Å distant from the heme group. Our results support a previously proposed mechanical signaling model, whereby the cysteine decoordination associated with gas ligand binding leads to breaking of a hydrogen bond with an arginine residue on a neighbouring helix. In turn, this leads to a shift in position of the helix, and hence also of the PLP cofactor, ultimately disrupting a key hydrogen bond that stabilizes the PLP in its catalytically active form.
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Affiliation(s)
- Neil R McFarlane
- Department of Chemistry, KU Leuven, Celestijnenlaan 200f-box 2404, B-3001 Leuven, Belgium.
| | - Jiangli Gui
- Department of Chemistry, KU Leuven, Celestijnenlaan 200f-box 2404, B-3001 Leuven, Belgium.
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry Budapest University of Technology and Economics H-1111 Budapest, Műegyeten rakpart 3, Hungary.
| | - Jeremy N Harvey
- Department of Chemistry, KU Leuven, Celestijnenlaan 200f-box 2404, B-3001 Leuven, Belgium.
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3
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Jiang M, Yu CH, Xu Z, Qin Z. Binding of Carbon Monoxide to Hemoglobin in an Oxygen Environment: Force Field Development for Molecular Dynamics. J Chem Theory Comput 2024; 20:4229-4238. [PMID: 38400860 PMCID: PMC11137813 DOI: 10.1021/acs.jctc.4c00029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 02/26/2024]
Abstract
Carbon monoxide (CO) is a byproduct of the incomplete combustion of carbon-based fuels, such as wood, coal, gasoline, or natural gas. As incomplete combustion in a fire accident or in an engine, massively produced CO leads to a serious life threat because CO competes with oxygen (O2) binding to hemoglobin and makes people suffer from hypoxia. Although there is hyperbaric O2 therapy for patients with CO poisoning, the nanoscale mechanism of CO dissociation in the O2-rich environment is not completely understood. In this study, we construct the classical force field parameters compatible with the CHARMM for simulating the coordination interactions between hemoglobin, CO, and O2, and use the force field to reveal the impact of O2 on the binding strength between hemoglobin and CO. Density functional theory and Car-Parrinello molecular dynamics simulations are used to obtain the bond energy and equilibrium geometry, and we used machine learning enabled via a feedforward neural network model to obtain the classical force field parameters. We used steered molecular dynamics simulations with a force field to characterize the mechanical strength of the hemoglobin-CO bond before rupture under different simulated O2-rich environments. The results show that as O2 approaches the Fe2+ of heme at a distance smaller than ∼2.8 Å, the coordination bond between CO and Fe2+ is reduced to 50% bond strength in terms of the peak force observed in the rupture process. This weakening effect is also shown by the free energy landscape measured by our metadynamics simulation. Our work suggests that the O2-rich environment around the hemoglobin-CO bond effectively weakens the bonding, so that designing of O2 delivery vector to the site is helpful for alleviating CO binding, which may shed light on de novo drug design for CO poisoning.
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Affiliation(s)
- Mingrui Jiang
- Laboratory
for Multiscale Material Modeling, Syracuse
University, 151L Link Hall, Syracuse, NY 13244, USA
- Department
of Civil and Environmental Engineering, Syracuse University, 151L Link Hall, Syracuse, NY 13244, USA
| | - Chi-Hua Yu
- Department
of Engineering Science, National Cheng Kung
University, No.1, University Road, Tainan City 701, Taiwan
| | - Zhiping Xu
- Applied
Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Zhao Qin
- Laboratory
for Multiscale Material Modeling, Syracuse
University, 151L Link Hall, Syracuse, NY 13244, USA
- Department
of Civil and Environmental Engineering, Syracuse University, 151L Link Hall, Syracuse, NY 13244, USA
- The
BioInspired Institute, Syracuse University, Syracuse, NY 13244, USA
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4
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Ri YK, Kim SA, Kye YH, Jong YC, Kang MS, Yu CJ. First-principles study of molecular hydrogen binding to heme in competition with O 2, NO and CO. RSC Adv 2024; 14:16629-16638. [PMID: 38784410 PMCID: PMC11110138 DOI: 10.1039/d4ra02091j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 05/03/2024] [Indexed: 05/25/2024] Open
Abstract
Molecular hydrogen shows antioxidant activity and distinct efficacy towards vascular diseases, but the understanding of this is not yet satisfactory at the atomic level. In this work, we study the binding properties of H2 to the heme group in relation with other diatomic molecules (DMs), including O2, NO and CO, and their displacement reactions, using first-principles calculations. We carry out molecular modeling of the heme group, using iron-porphyrin with the imidazole ligand, i.e., FePIm, and smaller models of Fe(CnHn+2N2)2NH3 with n = 3 and 1, and of molecular complexes of heme-DM and -H. Through analysis of optimized geometries and energetics, it is found that the order of binding strength of DMs or H to the Fe of heme is NO > O2 > CO > H > H2 for FePIm-based systems, while it is H > O2 > NO > CO > H2 for model-based systems. We calculate the activation energies for displacement reactions of H2 and H by other DMs, revealing that the H2 displacements occur spontaneously while the H displacements require a large amount of energy. Finally, our calculations corroborate that the rate constants increase with increasing temperature according to the Arrhenius relation.
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Affiliation(s)
- Yun-Kyong Ri
- Chair of Computational Materials Design, Faculty of Materials Science, Kim Il Sung University PO Box 76 Pyongyang Democratic People's Republic of Korea
| | - Song-Ae Kim
- Institute of Molecular Biology, Faculty of Life Science, Kim Il Sung University PO Box 76 Pyongyang Democratic People's Republic of Korea
| | - Yun-Hyok Kye
- Chair of Computational Materials Design, Faculty of Materials Science, Kim Il Sung University PO Box 76 Pyongyang Democratic People's Republic of Korea
| | - Yu-Chol Jong
- Chair of Chemical Process, Faculty of Chemistry, Kim Il Sung University PO Box 76 Pyongyang Democratic People's Republic of Korea
| | - Myong-Su Kang
- Institute of Molecular Biology, Faculty of Life Science, Kim Il Sung University PO Box 76 Pyongyang Democratic People's Republic of Korea
| | - Chol-Jun Yu
- Chair of Computational Materials Design, Faculty of Materials Science, Kim Il Sung University PO Box 76 Pyongyang Democratic People's Republic of Korea
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Dabbish E, Scoditti S, Shehata MNI, Ritacco I, Ibrahim MAA, Shoeib T, Sicilia E. Insights on cyclophosphamide metabolism and anticancer mechanism of action: A computational study. J Comput Chem 2024; 45:663-670. [PMID: 38088485 DOI: 10.1002/jcc.27280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 03/02/2024]
Abstract
The oxazaphosphorine cyclophosphamide (CP) is a DNA-alkylating agent commonly used in cancer chemotherapy. This anticancer agent is administered as a prodrug activated by a liver cytochrome P450-catalyzed 4-hydroxylation reaction that yields the active, cytotoxic metabolite. The primary metabolite, 4-hydroxycyclophosphamide, equilibrates with the ring-open aldophosphamide that undergoes β-elimination to yield the therapeutically active DNA cross-linking phosphoramide mustard and the byproduct acrolein. The present paper presents a DFT investigation of the different metabolic phases and an insight into the mechanism by which CP exerts its cytotoxic action. A detailed computational analysis of the energy profiles describing all the involved transformations and the mechanism of DNA alkylation is given with the aim to contribute to an increase of knowledge that, after more than 60 years of unsuccessful attempts, can lead to the design and development of a new generation of oxazaphosphorines.
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Affiliation(s)
- Eslam Dabbish
- Department of Chemistry, The American University in Cairo, New Cairo, Egypt
| | - Stefano Scoditti
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata, Italy
| | - Mohammed N I Shehata
- Computational Chemistry Laboratory, Chemistry Department, Faculty of Science, Minia University, Minia, Egypt
| | - Ida Ritacco
- Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, Salerno, Italy
| | - Mahmoud A A Ibrahim
- Computational Chemistry Laboratory, Chemistry Department, Faculty of Science, Minia University, Minia, Egypt
- School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Tamer Shoeib
- Department of Chemistry, The American University in Cairo, New Cairo, Egypt
| | - Emilia Sicilia
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata, Italy
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6
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Wang Z, Wang Z, Wang G, Zhang Q, Wang Q, Wang W. New insight into biodegradation mechanism of phenylurea herbicides by cytochrome P450 enzymes: Successive N-demethylation mechanism. ENVIRONMENT INTERNATIONAL 2023; 182:108332. [PMID: 37988774 DOI: 10.1016/j.envint.2023.108332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 11/12/2023] [Accepted: 11/15/2023] [Indexed: 11/23/2023]
Abstract
Phenylurea herbicides (PUHs) present one of the most important herbicides, which have cause serious effects on ecological environment and humans. Nowadays enzyme strategy shows great advantages in degradation of PUHs. Here density functional theory (DFT), quantitative structure - activity relationship (QSAR) and quantum mechanics/molecular mechanics (QM/MM) approaches are used to investigate the degradation mechanism of PUHs catalyzed by P450 enzymes. Two successive N-demethylation pathways are identified and two hydrogen abstraction (H-abstraction) reaction pathways are identified as the rate-determining step through high-throughput DFT calculations. The Boltzmann-weighted average energy barrier of the second H-abstraction pathway (19.95 kcal/mol) is higher than that of the first H-abstraction pathway (16.80 kcal/mol). Two QSAR models are established to predict the energy barriers of the two H-abstraction pathways based on the quantum chemical descriptors and mordred molecular descriptors. The determination coefficient (R2) values of QSAR models are > 0.9, which reveal that the established QSAR models have great predictive capability. QM/MM calculations indicate that human P450 enzymes are more efficient in degradation of PUHs than crop and weed P450 enzymes. Correlations between energy barriers and key structural/charge parameters are revealed and key parameters that have influence on degradation efficiency of PUHs are identified. This study provides lateral insights into the biodegradation strategy and removal method of PUHs and valuable information for designing or engineering of highly efficient degradation enzymes and genetically modified crops.
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Affiliation(s)
- Zijian Wang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Zhong Wang
- Shandong Nuclear and Radiation Safety Monitoring Center, Jinan 250117, PR China
| | - Guoqiang Wang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China.
| | - Qiao Wang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
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7
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Radoń M. Benchmarks for transition metal spin-state energetics: why and how to employ experimental reference data? Phys Chem Chem Phys 2023; 25:30800-30820. [PMID: 37938035 DOI: 10.1039/d3cp03537a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Accurate prediction of energy differences between alternative spin states of transition metal complexes is essential in computational (bio)inorganic chemistry-for example, in characterization of spin crossover materials and in the theoretical modeling of open-shell reaction mechanisms-but it remains one of the most compelling problems for quantum chemistry methods. A part of this challenge is to obtain reliable reference data for benchmark studies, as even the highest-level applicable methods are known to give divergent results. This Perspective discusses two possible approaches to method benchmarking for spin-state energetics: using either theoretically computed or experiment-derived reference data. With the focus on the latter approach, an extensive general review is provided for the available experimental data of spin-state energetics and their interpretations in the context of benchmark studies, targeting the possibility of back-correcting the vibrational effects and the influence of solvents or crystalline environments. With a growing amount of experience, these effects can be now not only qualitatively understood, but also quantitatively modeled, providing the way to derive nearly chemically accurate estimates of the electronic spin-state gaps to be used as benchmarks and advancing our understanding of the phenomena related to spin states in condensed phases.
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Affiliation(s)
- Mariusz Radoń
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Krakow, Poland.
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8
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Ma G, Wang Q, Ma K, Chen Y, Lu J, Zhang J, Wang X, Wei X, Yu H. Enantioselective metabolism of novel chiral insecticide Paichongding by human cytochrome P450 3A4: A computational insight. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 333:122088. [PMID: 37348694 DOI: 10.1016/j.envpol.2023.122088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/17/2023] [Accepted: 06/19/2023] [Indexed: 06/24/2023]
Abstract
As a novel chiral neonicotinoid insecticide, Paichongding (IPP) has been widely applied in agriculture due to its excellent insecticidal activity. However, the enantioselective metabolism of IPP stereoisomers (5R7R-IPP, 5S7S-IPP, 5R7S-IPP, and 5S7R-IPP) mediated by enzymes in non-target organisms, especially the cytochrome P450s (CYPs), remains unknown. To address this knowledge gap, we developed an integrated computational framework to elucidate the binding interactions and enantioselective metabolism of IPP stereoisomers in human CYP3A4. The results reveal that 5R7R-IPP shows much stronger binding affinity to CYP3A4 than 5S7S-IPP, while enantiomers 5R7S-IPP and 5S7R-IPP have no essential difference in their binding potential, owing to their specific interactions with key CYP3A4 residues. Although enantiomers 5R7R-IPP and 5S7S-IPP feature distinct binding modes resulting from the chiral differences, their transformation activities are slightly different, with C5 and C13 being the primary metabolic sites, respectively. In contrast, CYP3A4 preferably metabolizes 5R7S-IPP over 5S7R-IPP. The metabolism of epimers 5R7R-IPP and 5R7S-IPP share C5-hydroxylation routes due to the conserved 5R-conformaitons, but differ with the transformation routes at C11/C13 and C3 sites. The 7R-chirality of 5S7R-IPP significantly reduces the metabolic potency compared to 5S7S-IPP. CYP3A4-catalyzed hydroxylation and desaturation of IPP stereoisomers generate various chiral metabolites, with C5- and C13-hydroxyIPPs further transforming into depropylated products. Furthermore, the toxicity assessment reveals that IPP, along with the majority of its hydroxylated, desaturated, and depropylated metabolites, can potentially induce adverse effects on human health, specifically hepatotoxicity, respiratory toxicity, and carcinogenicity. This study provides valuable insights into the enantioselective fate of chiral IPP metabolism by CYP3A4, and the identified metabolites can serve as potential biomarkers for monitoring IPP exposure and associated health risk in human body.
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Affiliation(s)
- Guangcai Ma
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Qiuyi Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Kan Ma
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Yewen Chen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Jiayu Lu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Jing Zhang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Xueyu Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Xiaoxuan Wei
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China.
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Ma X, Albertsma J, Gabriels D, Horst R, Polat S, Snoeks C, Kapteijn F, Eral HB, Vermaas DA, Mei B, de Beer S, van der Veen MA. Carbon monoxide separation: past, present and future. Chem Soc Rev 2023; 52:3741-3777. [PMID: 37083229 PMCID: PMC10243283 DOI: 10.1039/d3cs00147d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Indexed: 04/22/2023]
Abstract
Large amounts of carbon monoxide are produced by industrial processes such as biomass gasification and steel manufacturing. The CO present in vent streams is often burnt, this produces a large amount of CO2, e.g., oxidation of CO from metallurgic flue gasses is solely responsible for 2.7% of manmade CO2 emissions. The separation of N2 from CO due to their very similar physical properties is very challenging, meaning that numerous energy-intensive steps are required for CO separation, making the CO separation from many process streams uneconomical in spite of CO being a valuable building block in the production of major chemicals through C1 chemistry and the production of linear hydrocarbons by the Fischer-Tropsch process. The development of suitable processes for the separation of carbon monoxide has both industrial and environmental significance. Especially since CO is a main product of electrocatalytic CO2 reduction, an emerging sustainable technology to enable carbon neutrality. This technology also requires an energy-efficient separation process. Therefore, there is a great need to develop energy efficient CO separation processes adequate for these different process streams. As such the urgency of separating carbon monoxide is gaining greater recognition, with research in the field becoming more and more crucial. This review details the principles on which CO separation is based and provides an overview of currently commercialised CO separation processes and their limitations. Adsorption is identified as a technology with the potential for CO separation with high selectivity and energy efficiency. We review the research efforts, mainly seen in the last decades, in developing new materials for CO separation via ad/bsorption and membrane technology. We have geared our review to both traditional CO sources and emerging CO sources, including CO production from CO2 conversion. To that end, a variety of emerging processes as potential CO2-to-CO technologies are discussed and, specifically, the need for CO capture after electrochemical CO2 reduction is highlighted, which is still underexposed in the available literature. Altogether, we aim to highlight the knowledge gaps that could guide future research to improve CO separation performance for industrial implementation.
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Affiliation(s)
- Xiaozhou Ma
- Chemical Engineering Department, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
| | - Jelco Albertsma
- Chemical Engineering Department, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
| | - Dieke Gabriels
- Chemical Engineering Department, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
| | - Rens Horst
- Science and Technology Faculty, University Twente, Drienerlolaan 5, 7522 NB Enschede, The Netherlands
| | - Sevgi Polat
- Process & Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft, The Netherlands
- Chemical Engineering Department, Marmara University, 34854 İstanbul, Turkey
| | - Casper Snoeks
- Process & Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft, The Netherlands
| | - Freek Kapteijn
- Chemical Engineering Department, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
| | - Hüseyin Burak Eral
- Process & Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft, The Netherlands
| | - David A Vermaas
- Chemical Engineering Department, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
| | - Bastian Mei
- Industrial Chemistry, Ruhr-University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Sissi de Beer
- Science and Technology Faculty, University Twente, Drienerlolaan 5, 7522 NB Enschede, The Netherlands
| | - Monique Ann van der Veen
- Chemical Engineering Department, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
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10
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Zhang H, Wang X, Song R, Ding W, Li F, Ji L. Emerging Metabolic Profiles of Sulfonamide Antibiotics by Cytochromes P450: A Computational-Experimental Synergy Study on Emerging Pollutants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5368-5379. [PMID: 36921339 DOI: 10.1021/acs.est.3c00071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Metabolism, especially by CYP450 enzymes, is the main reason for mediating the toxification and detoxification of xenobiotics in humans, while some uncommon metabolic pathways, especially for emerging pollutants, probably causing idiosyncratic toxicity are easily overlooked. The pollution of sulfonamide antibiotics in aqueous system has attracted increasing public attention. Hydroxylation of the central amine group can trigger a series of metabolic processes of sulfonamide antibiotics in humans; however, this work parallelly reported the coupling and fragmenting initiated by amino H-abstraction of sulfamethoxazole (SMX) catalyzed by human CYP450 enzymes. Elucidation of the emerging metabolic profiles was mapped via a multistep synergy between computations and experiments, involving preliminary DFT computations and in vitro and in vivo assays, profiling adverse effects, and rationalizing the fundamental factors via targeted computations. Especially, the confirmed SMX dimer was shown to potentially act as a metabolism disruptor in humans, while spin aromatic delocalization resulting in the low electron donor ability of amino radicals was revealed as the fundamental factor to enable coupling of sulfonamide antibiotics by CYP450 through the nonconventional nonrebound pathway. This work may further strengthen the synergistic use of computations prior to experiments to avoid wasteful experimental screening efforts in environmental chemistry and toxicology.
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Affiliation(s)
- Huanni Zhang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaoqing Wang
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai 264003, China
| | - Runqian Song
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wen Ding
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
| | - Fei Li
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai 264003, China
| | - Li Ji
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
- International Center for Research on Innovative Biobased Materials (ICRI-BioM)─International Research Agenda, Lodz University of Technology, Zeromskiego 116, Lodz 90-924, Poland
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11
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Gao Y, Hu X, Deng C, Wang M, Niu X, Luo N, Ji Y, Li G, An T. New insight into molecular mechanism of P450-Catalyzed metabolism of emerging contaminants and its consequence for human health: A case study of preservative methylparaben. ENVIRONMENT INTERNATIONAL 2023; 174:107890. [PMID: 37001212 DOI: 10.1016/j.envint.2023.107890] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/13/2023] [Accepted: 03/15/2023] [Indexed: 06/19/2023]
Abstract
Hydroxylated metabolites in the living body are considered as a potential biomarker of exposure to emerging contaminations (ECs) and breast cancer, but their formation mechanism has not received enough attention. Besides, the adverse impacts of metabolites during the metabolic transformation of ECs largely remain unknown. In this study, we employed a density functional calculation combing with in-vitro incubation of human liver microsomes to explore the bio-transformation of preservative methylparaben (MPB) in human bodies. Our results showed that hydroxylated metabolites of MPB (OH-MPB) were observed experimentally, while a formation mechanism was revealed at the molecular level. That is, hydroxylated metabolite was exclusively formed via the hydrogen abstraction from the phenolic hydroxyl group of MPB followed by the OH-rebound pathway, rather than the direct hydroxylation on the benzene ring. The increasing of hydroxyl groups on ECs could improve the metabolisms. This was confirmed in the metabolism of ECs without hydroxyl group and with multiple-hydroxyl groups, respectively. Furthermore, toxicity assessments show that compared to parent MPB, the hydroxylated metabolites have increased negative impacts on the gastrointestinal system and liver. A semiquinone product exhibits potential damage in the cardiovascular system and epoxides are toxic to the blood and gastrointestinal system. The findings deepen our insight into the biotransformation of parabens in human health, especially by providing health warnings about the potential impacts caused by semiquinone and epoxides.
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Affiliation(s)
- Yanpeng Gao
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xinyi Hu
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Chuyue Deng
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Mei Wang
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xiaolin Niu
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Na Luo
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Yuemeng Ji
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| | - Guiying Li
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Taicheng An
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
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12
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Ji L, Zhang H, Ding W, Song R, Han Y, Yu H, Paneth P. Theoretical Kinetic Isotope Effects in Establishing the Precise Biodegradation Mechanisms of Organic Pollutants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4915-4929. [PMID: 36926881 DOI: 10.1021/acs.est.2c04755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Compound-specific isotope analysis (CSIA) for natural isotope ratios has been recognized as a promising tool to elucidate biodegradation pathways of organic pollutants by microbial enzymes by relating reported kinetic isotope effects (KIEs) to apparent KIEs (AKIEs) derived from bulk isotope fractionations (εbulk). However, for many environmental reactions, neither are the reference KIE ranges sufficiently narrow nor are the mechanisms elucidated to the point that rate-determining steps have been identified unequivocally. In this work, besides providing reference KIEs and rationalizing AKIEs, good relationships have been explained by DFT computations for diverse biodegradation pathways with known enzymatic models between the theoretical isotope fractionations (εbulk') from intrinsic KIEs on the rate-determining steps and the observed εbulk. (1) To confirm the mechanistic details of previously reported pathway-dependent CSIA, it includes isotope changes in MTBE biodegradation between hydroxylation by CYP450 and SN2 reaction by cobalamin-dependent methyltransferase, the regioselectivity of toluene biodegradation by CYP450, and the rate-determining step in toluene biodegradation by benzylsuccinate synthase. (2) To yield new fundamental insights into some unclear biodegradation pathways, it consists of the oxidative function of toluene dioxygenase in biodegradation of TCE, the epoxidation mode in biodegradation of TCE by toluene 4-monooxygenase, and the weighted average mechanism in biodegradation of cDCE by CYP450.
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Affiliation(s)
- Li Ji
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Huanni Zhang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Wen Ding
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Runqian Song
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Ye Han
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Piotr Paneth
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, Lodz 90-924, Poland
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13
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Shaya J, Aloum L, Lu CS, Corridon PR, Aoudi A, Shunnar A, Alefishat E, Petroianu G. Theoretical Study of Hydroxylation of α- and β-Pinene by a Cytochrome P450 Monooxygenase Model. Int J Mol Sci 2023; 24:ijms24065150. [PMID: 36982225 PMCID: PMC10048887 DOI: 10.3390/ijms24065150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 03/30/2023] Open
Abstract
Previous studies on biocatalytic transformations of pinenes by cytochrome P450 (CYP) enzymes reveal the formation of different oxygenated products from a single substrate due to the multistate reactivity of CYP and the many reactive sites in the pinene scaffold. Up until now, the detailed mechanism of these biocatalytic transformations of pinenes have not been reported. Hereby, we report a systematic theoretical study of the plausible hydrogen abstraction and hydroxylation reactions of α- and β-pinenes by CYP using the density functional theory (DFT) method. All DFT calculations in this study were based on B3LYP/LAN computational methodology using the Gaussian09 software. We used the B3LYP functional with corrections for dispersive forces, BSSE, and anharmonicity to study the mechanism and thermodynamic properties of these reactions using a bare model (without CYP) and a pinene-CYP model. According to the potential energy surface and Boltzmann distribution for radical conformers, the major reaction products of CYP-catalyzed hydrogen abstraction from β-pinene are the doublet trans (53.4%) and doublet cis (46.1%) radical conformer at delta site. The formation of doublet cis/trans hydroxylated products released a total Gibbs free energy of about 48 kcal/mol. As for alpha pinene, the most stable radicals were trans-doublet (86.4%) and cis-doublet (13.6%) at epsilon sites, and their hydroxylation products released a total of ~50 kcal/mol Gibbs free energy. Our results highlight the likely C-H abstraction and oxygen rebounding sites accounting for the multi-state of CYP (doublet, quartet, and sextet spin states) and the formation of different conformers due to the presence of cis/trans allylic hydrogen in α-pinene and β-pinene molecules.
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Affiliation(s)
- Janah Shaya
- Department of Chemistry, College of Arts and Sciences, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Lujain Aloum
- Department of Pharmacology, College of Medicine and Health Sciences, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Chung-Shin Lu
- Department of General Education, National Taichung University of Science and Technology, Taichung 404, Taiwan, China
| | - Peter R Corridon
- Department of Immunology and Physiology, College of Medicine and Health Sciences, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Biomedical Engineering and Healthcare Engineering Innovation Center, Khalifa University, Abu Dhabi 127788, United Arab Emirates
- Center for Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Abdulrahman Aoudi
- Department of Chemistry, College of Arts and Sciences, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Abeer Shunnar
- Department of Chemistry, College of Arts and Sciences, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Eman Alefishat
- Department of Pharmacology, College of Medicine and Health Sciences, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Center for Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman 11972, Jordan
| | - Georg Petroianu
- Department of Pharmacology, College of Medicine and Health Sciences, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
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14
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Ramos DR, Furtmüller PG, Obinger C, Peña-Gallego Á, Pérez-Juste I, Santaballa JA. Common Reactivity and Properties of Heme Peroxidases: A DFT Study of Their Origin. Antioxidants (Basel) 2023; 12:antiox12020303. [PMID: 36829861 PMCID: PMC9952403 DOI: 10.3390/antiox12020303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/06/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
Electronic structure calculations using the density-functional theory (DFT) have been performed to analyse the effect of water molecules and protonation on the heme group of peroxidases in different redox (ferric, ferrous, compounds I and II) and spin states. Shared geometries, spectroscopic properties at the Soret region, and the thermodynamics of peroxidases are discussed. B3LYP and M06-2X density functionals with different basis sets were employed on a common molecular model of the active site (Fe-centred porphine and proximal imidazole). Computed Gibbs free energies indicate that the corresponding aquo complexes are not thermodynamically stable, supporting the five-coordinate Fe(III) centre in native ferric peroxidases, with a water molecule located at a non-bonding distance. Protonation of the ferryl oxygen of compound II is discussed in terms of thermodynamics, Fe-O bond distances, and redox properties. It is demonstrated that this protonation is necessary to account for the experimental data, and computed Gibbs free energies reveal pKa values of compound II about 8.5-9.0. Computation indicates that the general oxidative properties of peroxidase intermediates, as well as their reactivity towards water and protons and Soret bands, are mainly controlled by the iron porphyrin and its proximal histidine ligand.
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Affiliation(s)
- Daniel R. Ramos
- Chemical Reactivity & Photoreactivity Group (React!), Department of Chemistry, CICA & Faculty of Sciences, Universidade da Coruña, Campus da Zapateira, E-15071 A Coruña, Spain
- Departamento de Química Física, Universidade de Vigo, Campus Universitario Lagoas-Marcosende, E-36310 Vigo, Spain
- Correspondence: (D.R.R.); (J.A.S.)
| | - Paul G. Furtmüller
- Institute of Biochemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Christian Obinger
- Institute of Biochemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Ángeles Peña-Gallego
- Departamento de Química Física, Universidade de Vigo, Campus Universitario Lagoas-Marcosende, E-36310 Vigo, Spain
| | - Ignacio Pérez-Juste
- Departamento de Química Física, Universidade de Vigo, Campus Universitario Lagoas-Marcosende, E-36310 Vigo, Spain
| | - J. Arturo Santaballa
- Chemical Reactivity & Photoreactivity Group (React!), Department of Chemistry, CICA & Faculty of Sciences, Universidade da Coruña, Campus da Zapateira, E-15071 A Coruña, Spain
- Correspondence: (D.R.R.); (J.A.S.)
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15
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Liu S, Xia S, Yue D, Sun H, Hirao H. The Bonding Nature of Fe–CO Complexes in Heme Proteins. Inorg Chem 2022; 61:17494-17504. [DOI: 10.1021/acs.inorgchem.2c02387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Shuyang Liu
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong518172, P. R. China
| | - Songyan Xia
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong518172, P. R. China
| | - Dongxiao Yue
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong518172, P. R. China
| | - Haoran Sun
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong518172, P. R. China
| | - Hajime Hirao
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong518172, P. R. China
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16
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Rooein M, Varganov SA. How to calculate the rate constants for nonradiative transitions between the MS components of spin multiplets? Mol Phys 2022. [DOI: 10.1080/00268976.2022.2116364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Mitra Rooein
- Department of Chemistry, University of Nevada, Reno, NV, USA
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17
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Rozza AM, Papp M, McFarlane NR, Harvey JN, Oláh J. The Mechanism of Biochemical NO-Sensing: Insights from Computational Chemistry. Chemistry 2022; 28:e202200930. [PMID: 35670519 PMCID: PMC9542423 DOI: 10.1002/chem.202200930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Indexed: 11/22/2022]
Abstract
The binding of small gas molecules such as NO and CO plays a major role in the signaling routes of the human body. The sole NO-receptor in humans is soluble guanylyl cyclase (sGC) - a histidine-ligated heme protein, which, upon NO binding, activates a downstream signaling cascade. Impairment of NO-signaling is linked, among others, to cardiovascular and inflammatory diseases. In the present work, we use a combination of theoretical tools such as MD simulations, high-level quantum chemical calculations and hybrid QM/MM methods to address various aspects of NO binding and to elucidate the most likely reaction paths and the potential intermediates of the reaction. As a model system, the H-NOX protein from Shewanella oneidensis (So H-NOX) homologous to the NO-binding domain of sGC is used. The signaling route is predicted to involve NO binding to form a six-coordinate intermediate heme-NO complex, followed by relatively facile His decoordination yielding a five-coordinate adduct with NO on the distal side with possible isomerization to the proximal side through binding of a second NO and release of the first one. MD simulations show that the His sidechain can quite easily rotate outward into solvent, with this motion being accompanied in our simulations by shifts in helix positions that are consistent with this decoordination leading to significant conformational change in the protein.
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Affiliation(s)
- Ahmed M. Rozza
- Department of Inorganic and Analytical ChemistryBudapest University of Technology and Economics1111Budapest Műegyetem rakpart 3.Hungary
- Department of BiotechnologyFaculty of AgricultureAl-Azhar UniversityCairo11651Egypt
| | - Marcell Papp
- Department of Inorganic and Analytical ChemistryBudapest University of Technology and Economics1111Budapest Műegyetem rakpart 3.Hungary
| | - Neil R. McFarlane
- Department of ChemistryKU Leuven3001LeuvenCelestijnenlaan 200 f- box 2404Belgium
| | - Jeremy N. Harvey
- Department of ChemistryKU Leuven3001LeuvenCelestijnenlaan 200 f- box 2404Belgium
| | - Julianna Oláh
- Department of Inorganic and Analytical ChemistryBudapest University of Technology and Economics1111Budapest Műegyetem rakpart 3.Hungary
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18
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Zhang H, Wang C, Guo F, Jin L, Song R, Yang F, Ji L, Yu H. In Silico simulation of Cytochrome P450-Mediated metabolism of aromatic amines: A case study of N-Hydroxylation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 237:113544. [PMID: 35483145 DOI: 10.1016/j.ecoenv.2022.113544] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 04/12/2022] [Accepted: 04/17/2022] [Indexed: 06/14/2023]
Abstract
Aromatic amines, the widely used raw materials in industry, cause long-term exposure to human bodies. They can be metabolized by cytochrome P450 enzymes to form active electrophilic compounds, which will potentially react with nucleophilic DNA to exert carcinogenesis. The short lifetime and versatility of the oxidant (a high-valent iron (IV)-oxo species, compound I) of P450 enzymes prompts us to use theoretical methods to investigate the metabolism of aromatic amines. In this work, the density functional theory (DFT) has been employed to simulate the hydroxylation metabolism through H-abstraction and to calculate the activation energy of this reaction for 28 aromatic amines. The results indicate that the steric effects, inductive effects and conjugative effects greatly contribute to the metabolism activity of the chemicals. The further correlation reveals that the dissociation energy of -NH2 (BDEN-H) can successfully predict the time-consuming calculated activation energy (R2 for aromatic and heteroaromatic amines are 0.93 and 0.86, respectively), so BDEN-H can be taken as a key parameter to characterize the relative stability of aromatic amines in P450 enzymes and further to quickly assess their potential toxicity. The validation results prove such relationship has good statistical performance (qcv2 for aromatic and heteroaromatic amines are 0.95 and 0.90, respectively) and can be used to other aromatic amines in the application domain, greatly reducing computational cost and providing useful support for experimental research.
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Affiliation(s)
- Huanni Zhang
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Chenchen Wang
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Fangjie Guo
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China; Quality and Safety Engineering Institute of Food and Drug, School of Management Engineering and Electronic Commerce, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China
| | - Lingmin Jin
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, Jinhua 321004, China
| | - Runqian Song
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Fangxing Yang
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Li Ji
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China; School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, Jinhua 321004, China.
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19
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Chai L, Zhang H, Guo F, Song R, Yu H, Ji L. Computational Investigation of the Bisphenolic Drug Metabolism by Cytochrome P450: What Factors Favor Intramolecular Phenol Coupling. Chem Res Toxicol 2022; 35:440-449. [PMID: 35230092 DOI: 10.1021/acs.chemrestox.1c00350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Intramolecular phenol coupling reactions of alkaloids can lead to active metabolites catalyzed by the mammalian cytochrome P450 enzyme (P450); however, the mechanistic knowledge of such an "unusual" process is lacking. This work performs density functional theory computations to reveal the P450-mediated metabolic pathway leading from R-reticuline to the morphine precursor salutaridine by exploring possible intramolecular phenol coupling mechanisms involving diradical coupling, radical addition, and electron transfer. The computed results show that the outer-sphere electron transfer with a high barrier (>20.0 kcal/mol) is unlikely to happen. However, for inter-sphere intramolecular phenol coupling, it reveals that intramolecular phenol coupling of R-reticuline proceeds via the diradical mechanism consecutively by compound I and protonated compound II of P450 rather than the radical addition mechanism. The existence of a much higher radical rebound barrier than that of H-abstraction in the quartet high-spin state can endow the R-reticuline phenoxy radical with a sufficient lifetime to enable intramolecular phenol coupling, while the H-abstraction/radical rebound mode with a negligible rebound barrier leading to phenol hydroxylation can only happen in the doublet low-spin state. Therefore, the ratio [coupling]/[hydroxylation] can be approximately reflected by the relative yield of the high-spin and low-spin H-abstraction by P450, which thus can provide a theoretical ratio of 16:1 for R-reticuline, which is in accordance with previous experimental results. Especially, the high rebound barrier of the phenoxy radical derived from the weak electron-donating ability of the phenoxy radical is revealed as an intrinsic nature. Therefore, the revealed intramolecular phenol coupling mechanism can be potentially extended to several other bisphenolic drugs to infer groups of unexpected metabolites in organisms.
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Affiliation(s)
- Lihong Chai
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China.,College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China.,Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Lichtenbergstrasse 4, Munich 81377, Germany
| | - Huanni Zhang
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Fangjie Guo
- School of Management Engineering and Electronic Commerce, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Runqian Song
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Li Ji
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China.,College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China.,Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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20
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NAST: Nonadiabatic Statistical Theory Package for Predicting Kinetics of Spin-Dependent Processes. Top Curr Chem (Cham) 2022; 380:15. [PMID: 35201520 DOI: 10.1007/s41061-022-00366-w] [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: 09/03/2021] [Accepted: 01/15/2022] [Indexed: 10/19/2022]
Abstract
We present a nonadiabatic statistical theory (NAST) package for predicting kinetics of spin-dependent processes, such as intersystem crossings, spin-forbidden unimolecular reactions, and spin crossovers. The NAST package can calculate the probabilities and rates of transitions between the electronic states of different spin multiplicities. Both the microcanonical (energy-dependent) and canonical (temperature-dependent) rate constants can be obtained. Quantum effects, including tunneling, zero-point vibrational energy, and reaction path interference, can be accounted for. In the limit of an adiabatic unimolecular reaction proceeding on a single electronic state, NAST reduces to the traditional transition state theory. Because NAST requires molecular properties at only a few points on potential energy surfaces, it can be applied to large molecular systems, used with accurate high-level electronic structure methods, and employed to study slow nonadiabatic processes. The essential NAST input data include the nuclear Hessian at the reactant minimum, as well as the nuclear Hessians, energy gradients, and spin-orbit coupling at the minimum energy crossing point (MECP) between two states. The additional computational tools included in the NAST package can be used to extract the required input data from the output files of electronic structure packages, calculate the effective Hessian at the MECP, and fit the reaction coordinate for more advanced NAST calculations. We describe the theory, its implementation, and three examples of application to different molecular systems.
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21
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Han C, Zhu W, Ma G, Chen Y, Li X, Wei X, Yu H. Computational insight into biotransformation of halophenols by cytochrome P450: Mechanism and reactivity for epoxidation. CHEMOSPHERE 2022; 286:131708. [PMID: 34352543 DOI: 10.1016/j.chemosphere.2021.131708] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 07/11/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Halophenols (XPs) have aroused great interests due to their high toxicity and low biodegradability. Previous experimental studies have shown that XPs can be catalytically transformed into epoxides and haloquinones by cytochrome P450 enzymes (CYPs). However, these metabolites have never been detected directly. Moreover, the effects of the reaction site and the type and number of halogen substituents on the biotransformation reactivity of halophenols still remain unknown. In this work, we performed density functional theory (DFT) calculations to simulate the CYP-mediated biotransformation of 36 XPs with mono-, di-, and tri-halogen (F, Cl, and Br) substitutions to unravel the mechanism and relevant kinetics of XPs epoxidation. The whole epoxidation process consists of initial rate-determining O-addition and subsequent ring-closure steps. The simulation results show that the epoxidation in low-spin (LS) state is kinetically preferred over that in high-spin (HS) state, and the formation of epoxide metabolite is strongly exothermic. For all XPs, the epoxidation reactivity follows the order of ortho/para O-addition > meta O-addition. Moreover, the O-addition with higher energy barriers roughly corresponds to chlorophenols and fluorophenols with more halogen atoms. Compared with dichlorophenols, the additional ortho-Cl substitution on trichlorophenols can slightly increase the energy barriers of meta O-addition. By contrast, the additional inclusion of an ortho-Cl to monochlorophenols enhances the meta O-addition reactivity of dichlorophenols. Overall, the present work clarifies the biotransformation routes of XPs to produce epoxides, and identifies the key factors affecting the epoxidation reactivity, which are beneficial in understanding comprehensively the metabolic fate and toxicity of XPs.
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Affiliation(s)
- Cenyang Han
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Wenyou Zhu
- School of Materials and Chemical Engineering, Xuzhou University of Technology, Xuzhou, Jiangsu, 221018, China
| | - Guangcai Ma
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China.
| | - Yewen Chen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Xinqi Li
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Xiaoxuan Wei
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China.
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22
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Fateminasab F, Aarabi M, de la Lande A, Omidyan R. Theoretical insights on the effect of environments on binding of CO to the Heme :Ferrous and Ferric systems. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Chai L, Zhang H, Song R, Yang H, Yu H, Paneth P, Kepp KP, Akamatsu M, Ji L. Precision Biotransformation of Emerging Pollutants by Human Cytochrome P450 Using Computational-Experimental Synergy: A Case Study of Tris(1,3-dichloro-2-propyl) Phosphate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:14037-14050. [PMID: 34663070 DOI: 10.1021/acs.est.1c03036] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Precision biotransformation is an envisioned strategy offering detailed insights into biotransformation pathways in real environmental settings using experimentally guided high-accuracy quantum chemistry. Emerging pollutants, whose metabolites are easily overlooked but may cause idiosyncratic toxicity, are important targets of such a strategy. We demonstrate here that complex metabolic reactions of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) catalyzed by human CYP450 enzymes can be mapped via a three-step synergy strategy: (i) screening the possible metabolites via high-throughout (moderate-accuracy) computations; (ii) analyzing the proposed metabolites in vitro by human liver microsomes and recombinant human CYP450 enzymes; and (iii) rationalizing the experimental data via precise mechanisms using high-level targeted computations. Through the bilateral dialogues from qualitative to semi-quantitative to quantitative levels, we show how TDCIPP metabolism especially by CYP3A4 generates bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) as an O-dealkylation metabolite and bis(1,3-dichloro-2-propyl) 3-chloro-1-hydroxy-2-propyl phosphate (alcoholβ-dehalogen) as a dehalogenation/reduction metabolite via the initial rate-determining H-abstraction from αC- and βC-positions. The relative yield ratio [dehalogenation/reduction]/[O-dealkylation] is derived from the relative barriers of H-abstraction at the βC- and αC-positions by CYP3A4, estimated as 0.002 to 0.23, viz., an in vitro measured ratio of 0.04. Importantly, alcoholβ-dehalogen formation points to a new mechanism involving successive oxidation and reduction functions of CYP450, with its precursor aldehydeβ-dehalogen being a key intermediate detected by trapping assays and rationalized by computations. We conclude that the proposed three-step synergy strategy may meet the increasing challenge of elucidating biotransformation mechanisms of substantial synthesized organic compounds in the future.
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Affiliation(s)
- Lihong Chai
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Huanni Zhang
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Runqian Song
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Haohan Yang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Piotr Paneth
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Kasper P Kepp
- DTU Chemistry, Technical University of Denmark, Building 206, Kgs. Lyngby DK-2800, Denmark
| | - Miki Akamatsu
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Li Ji
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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24
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Shafizadeh N, Crestoni ME, de la Lande A, Soep B. Heme ligation in the gas phase. INT REV PHYS CHEM 2021. [DOI: 10.1080/0144235x.2021.1952006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | - Maria Elisa Crestoni
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma “La Sapienza”, Roma, Italy
| | | | - Benoît Soep
- ISMO-CNRS, Université Paris Saclay, Orsay Cedex, France
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25
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Wang M, Gao Y, Li G, An T. Increased adverse effects during metabolic transformation of short-chain chlorinated paraffins by cytochrome P450: A theoretical insight into 1-chlorodecane. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124391. [PMID: 33160786 DOI: 10.1016/j.jhazmat.2020.124391] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/14/2020] [Accepted: 10/25/2020] [Indexed: 05/22/2023]
Abstract
Short-chain chlorinated paraffins (SCCPs), frequently detected in human tissues or organs, can result in threat to human health by disturbing normal metabolism. However, their metabolism mechanisms and fates are largely unclear. Therefore, to better understand the impacts of SCCPs and their metabolites on the human health, the metabolic mechanism and kinetics of SCCPs by cytochrome P450 enzymes (CYPs) were explored using density functional theory employed 1-chlorodecane as a model SCCPs. The results show that 1-chlorodecane could be readily metabolized by CYPs, and the rate constant reaches up 42.3 s-1 in human body. Dechlorination of 1-chlorodecane is unlikely to occur and hydroxylation is dominated via H-abstraction pathways, especially from the intermediate C atom of 1-chlorodecane. The toxicity assessments suggest that the two metabolites, 10-chloro-decan-5-ol and 1-chlorodecanol could exhibit higher bioaccumulation, carcinogenicity and more serious damage on cardiovascular system after the metabolism of 1-chlorodecane. To our knowledge, this is the first study from the viewpoint of theoretical analysis to explore the metabolism of typical SCCPs in human body. It may provide deep insight into the metabolic transformation mechanism of SCCPs and cause the concerns about the adverse effects of their metabolites in human body.
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Affiliation(s)
- Mei Wang
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution control, Guangdong University of Technology, Guangzhou 510006, China
| | - Yanpeng Gao
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution control, Guangdong University of Technology, Guangzhou 510006, China
| | - Guiying Li
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution control, Guangdong University of Technology, Guangzhou 510006, China
| | - Taicheng An
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution control, Guangdong University of Technology, Guangzhou 510006, China.
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26
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Yamamoto Y, Hasegawa K, Shibata T, Momotake A, Ogura T, Yanagisawa S, Neya S, Suzuki A, Kobayashi Y, Saito M, Seto M, Ohta T. Effect of the Electron Density of the Heme Fe Atom on the Nature of Fe-O 2 Bonding in Oxy Myoglobin. Inorg Chem 2021; 60:1021-1027. [PMID: 33356193 DOI: 10.1021/acs.inorgchem.0c03123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mössbauer spectroscopy has been used to characterize oxygenated myoglobins (oxy Mbs) reconstituted with native and chemically modified 57Fe-enriched heme cofactors with different electron densities of the heme Fe atom (ρFe) and to elucidate the effect of a change in the ρFe on the nature of the bond between heme Fe and oxygen (O2), i.e., the Fe-O2 bond, in the protein. Quadrupole splitting (ΔEQ) was found to decrease with decreasing ρFe, and the observed ρFe-dependent ΔEQ confirmed an increase in the contribution of the ferric-superoxide (Fe3+-O2-) form to the resonance hybrid of the Fe-O2 fragment with decreasing ρFe. These observations explicitly accounted for the lowering of O2 affinity of the protein due to an increase in the O2 dissociation rate and a decrease in the autoxidation reaction rate of oxy Mb through decreasing H+ affinity of the bound ligand with decreasing ρFe. Therefore, the present study demonstrated the mechanism underlying the electronic control of O2 affinity and the autoxidation of the protein through the heme electronic structure. Carbon monoxide (CO) adducts of reconstituted Mbs (CO-Mbs) were similarly characterized, and we found that the resonance between the two canonical forms of the Fe-CO fragment was also affected by a change in ρFe. Thus, the nature of the Fe-ligand bond in the protein was found to be affected by the ρFe.
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Affiliation(s)
- Yasuhiko Yamamoto
- Department of Chemistry, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Kazuyasu Hasegawa
- Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, Tsukuba 305-8571, Japan
| | - Tomokazu Shibata
- Department of Chemistry, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Atsuya Momotake
- Department of Chemistry, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Takashi Ogura
- Department of Chemistry, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Sachiko Yanagisawa
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Saburo Neya
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Akihiro Suzuki
- Department of Physical Chemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Chuoh-Inohana, Chiba 260-8675, Japan
| | - Yasuhiro Kobayashi
- Department of Material Engineering, National Institute of Technology, Nagaoka College, Nagaoka 940-8532, Japan
| | - Makina Saito
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka 590-0494, Japan
| | - Makoto Seto
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka 590-0494, Japan
| | - Takehiro Ohta
- Department of Applied Chemistry, Faculty of Engineering, Sanyo-Onoda City University, Sanyo-Onoda, Yamaguchi 756-0884, Japan
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27
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Saito K, Watabe Y, Miyazaki T, Takayanagi T, Hasegawa JY. Spin-inversion mechanisms in O 2 binding to a model heme compound: A perspective from nonadiabatic wave packet calculations. J Comput Chem 2020; 41:2527-2537. [PMID: 32841410 DOI: 10.1002/jcc.26409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/18/2020] [Accepted: 08/08/2020] [Indexed: 12/13/2022]
Abstract
Spin-inversion dynamics in O2 binding to a model heme complex, which consisted of Fe(II)-porphyrin and imidazole, were studied using nonadiabatic wave packet dynamics calculations. We considered three active nuclear degrees of freedom in the dynamics, including the motions along the Fe-O distance, Fe-O-O angle, and Fe out-of-plane distance. Spin-free potential energy surfaces for the singlet, triplet, quintet, and septet states were developed using density functional theory calculations, and spin-orbit coupling elements were obtained from CASSCF-level electronic structure calculations. The spin-inversion mainly occurred between the singlet state and one of the triplet states due to large spin-orbit couplings and the contributions of other states were extremely small. The present quantum dynamics calculations suggested that the narrow crossing region model plays a dominant role in the O2 binding dynamics. In addition, the one-dimensional Landau-Zener model underestimated the nonadiabatic transition probability.
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Affiliation(s)
- Kohei Saito
- Department of Chemistry, Saitama University, Saitama City, Saitama, Japan
| | - Yuya Watabe
- Department of Chemistry, Saitama University, Saitama City, Saitama, Japan
| | - Takaaki Miyazaki
- Department of Chemistry, Saitama University, Saitama City, Saitama, Japan
| | | | - Jun-Ya Hasegawa
- Institute for Catalysis, Hokkaido University, Sapporo, Hokkaido, Japan
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28
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Blomberg MRA. Role of the Two Metals in the Active Sites of Heme Copper Oxidases-A Study of NO Reduction in cbb3 Cytochrome c Oxidase. Inorg Chem 2020; 59:11542-11553. [PMID: 32799475 DOI: 10.1021/acs.inorgchem.0c01351] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The superfamily of heme copper oxidases reduces molecular oxygen or nitric oxide, and the active sites comprise a high-spin heme group (a3 or b3) and a non-heme metal (CuB or FeB). The cbb3 C family of cytochrome c oxidases, with the high-spin heme b3 and CuB in the active site, is a subfamily of the heme copper oxidases that can reduce both molecular oxygen, which is the main substrate, and nitric oxide. The mechanism for NO reduction in cbb3 oxidase is studied here using hybrid density functional theory and compared to other cytochrome c oxidases (A and B families), with a high-spin heme a3 and CuB in the active site, and to cytochrome c dependent NO reductase, with a high-spin heme b3 and a non-heme FeB in the active site. It is found that the reaction mechanism and the detailed reaction energetics of the cbb3 oxidases are not similar to those of cytochrome c dependent NO reductase, which has the same type of high-spin heme group but a different non-heme metal. This is in contrast to earlier expectations. Instead, the NO reduction mechanism in cbb3 oxidases is very similar to that in the other cytochrome c oxidases, with the same non-heme metal, CuB, and is independent of the type of high-spin heme group. The conclusion is that the type of non-heme metal (CuB or FeB) in the active site of the heme copper oxidases is more important for the reaction mechanisms than the type of high-spin heme, at least for the NO reduction reaction. The reason is that the proton-coupled reduction potentials of the active site cofactors determine the energetics for the NO reduction reaction, and they depend to a larger extent on the non-heme metal. Observed differences in NO reduction reactivity among the various cytochrome c oxidases may be explained by differences outside the BNC, affecting the rate of proton transfer, rather than in the BNC itself.
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29
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Saito K, Watabe Y, Fujihara T, Takayanagi T, Hasegawa JY. Spin-inversion mechanisms in O 2 binding to a model heme complex revisited by density function theory calculations. J Comput Chem 2020; 41:1130-1138. [PMID: 32020659 DOI: 10.1002/jcc.26159] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/12/2020] [Accepted: 01/16/2020] [Indexed: 01/10/2023]
Abstract
Spin-inversion mechanisms in O2 binding to a model heme complex, consisting of Fe(II)-porphyrin and imidazole, were investigated using density-functional theory calculations. First, we applied the recently proposed mixed-spin Hamiltonian method to locate spin-inversion structures between different total spin multiplicities. Nine spin-inversion structures were successfully optimized for the singlet-triplet, singlet-quintet, triplet-quintet, and quintet-septet spin-inversion processes. We found that the singlet-triplet spin-inversion points are located around the potential energy surface region at short Fe-O distances, whereas the singlet-quintet and quintet-septet spin-inversion points are located at longer Fe-O distances. This suggests that both narrow and broad crossing models play roles in O2 binding to the Fe-porphyrin complex. To further understand spin-inversion mechanisms, we performed on-the-fly Born-Oppenheimer molecular dynamics calculations. The reaction coordinates, which are correlated to the spin-inversion dynamics between different spin multiplicities, are also discussed.
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Affiliation(s)
- Kohei Saito
- Department of Chemistry, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| | - Yuya Watabe
- Department of Chemistry, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| | - Takashi Fujihara
- Department of Chemistry, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| | - Toshiyuki Takayanagi
- Department of Chemistry, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| | - Jun-Ya Hasegawa
- Instituteof Catalysis, Hokkaido University, Kita 21, Nishi 10, Kita-ku, Sapporo, Hokkaido, 001-0021, Japan
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30
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Ma G, Yu H, Han C, Jia Y, Wei X, Wang Z. Binding and Metabolism of Brominated Flame Retardant β-1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane in Human Microsomal P450 Enzymes: Insights from Computational Studies. Chem Res Toxicol 2020; 33:1487-1496. [DOI: 10.1021/acs.chemrestox.0c00076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Guangcai Ma
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Cenyang Han
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Yue Jia
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Xiaoxuan Wei
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Zhiguo Wang
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, China
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31
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Tao Y, Pei Z, Bellonzi N, Mao Y, Zou Z, Liang W, Yang Z, Shao Y. Constructing Spin-Adiabatic States for the Modeling of Spin-Crossing Reactions. I. A Shared-Orbital Implementation. INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY 2020; 120:e26123. [PMID: 32773885 PMCID: PMC7409987 DOI: 10.1002/qua.26123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 11/19/2019] [Indexed: 06/11/2023]
Abstract
In the modeling of spin-crossing reactions, it has become popular to directly explore the spin-adiabatic surfaces. Specifically, through constructing spin-adiabatic states from a two-state Hamiltonian (with spin-orbit coupling matrix elements) at each geometry, one can readily employ advanced geometry optimization algorithms to acquire a "transition state" structure, where the spin crossing occurs. In this work, we report the implementation of a fully-variational spin-adiabatic approach based on Kohn-Sham density functional theory spin states (sharing the same set of molecular orbitals) and the Breit-Pauli one-electron spin-orbit operator. For three model spin-crossing reactions [predissociation of N2O, singlet-triplet conversion in CH2, and CO addition to Fe(CO)4], the spin-crossing points were obtained. Our results also indicated the Breit-Pauli one-electron spin-orbit coupling can vary significantly along the reaction pathway on the spin-adiabatic energy surface. On the other hand, due to the restriction that low-spin and high-spin states share the same set of molecular orbitals, the acquired spin-adiabatic energy surface shows a cusp (i.e. a first-order discontinuity) at the crossing point, which prevents the use of standard geometry optimization algorithms to pinpoint the crossing point. An extension with this restriction removed is being developed to achieve the smoothness of spin-adiabatic surfaces.
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Affiliation(s)
- Yunwen Tao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Zheng Pei
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Nicole Bellonzi
- Department of Chemistry, University of Pennsylvania, Philadelpha, PA 19104
| | - Yuezhi Mao
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Zhu Zou
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Wanzhen Liang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Zhibo Yang
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
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32
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Guo F, Chai L, Zhang S, Yu H, Liu W, Kepp KP, Ji L. Computational Biotransformation Profile of Emerging Phenolic Pollutants by Cytochromes P450: Phenol-Coupling Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2902-2912. [PMID: 31967796 DOI: 10.1021/acs.est.9b06897] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phenols are ubiquitous environmental pollutants, whose biotransformation involving phenol coupling catalyzed by cytochromes P450 may produce more lipophilic and toxic metabolites. Density functional theory (DFT) computations were performed to explore the debated phenol-coupling mechanisms, taking triclosan as a model substrate. We find that a diradical pathway facilitated by compound I and protonated compound II of P450 is favored vs alternative radical addition or electron-transfer mechanisms. The identified diradical coupling resembles a "two-state reactivity" from compound I characterized by significantly high rebound barriers of the phenoxy radicals, which can be formulated into three equations for calculating the ratio [coupling]/[hydroxylation]. A higher barrier for rebound than for H-abstraction in high-spin triclosan can facilitate the phenoxy radical dissociation and thus enable phenol coupling, while H-abstraction/radical rebound causing phenol hydroxylation via minor rebound barriers mostly occurs via the low-spin state. Therefore, oxidation of triclosan by P450 fits the first equation with a ratio [coupling]/[hydroxylation] of 1:4, consistent with experimental data indicating different extents of triclosan coupling (6-40%). The high rebound barrier of phenoxy radicals, as a key for the mechanistic identification of phenol coupling vs hydroxylation, originates from their weak electron donor ability due to spin aromatic delocalization. We envision that the revealed mechanism can be extended to the cross-coupling reactions between different phenolic pollutants, and the coupling reactions of several other aromatic pollutants, to infer unknown metabolites.
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Affiliation(s)
- Fangjie Guo
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Lihong Chai
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Shubin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, Jinhua 321004, P. R. China
| | - Weiping Liu
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Kasper P Kepp
- DTU Chemistry, Technical University of Denmark, Building 206, Kgs. Lyngby DK-2800, Denmark
| | - Li Ji
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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33
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Chai L, Ji S, Zhang S, Yu H, Zhao M, Ji L. Biotransformation Mechanism of Pesticides by Cytochrome P450: A DFT Study on Dieldrin. Chem Res Toxicol 2020; 33:1442-1448. [DOI: 10.1021/acs.chemrestox.0c00013] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lihong Chai
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Shujing Ji
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Shubin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, Jinhua 321004, China
| | - Meirong Zhao
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, China
| | - Li Ji
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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Mohammadi M, Aghaei FP, Noori B, Pakizeh E. Density Functional Theory modeling of the magnetic susceptibility of heme derivatives. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.110498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Blomberg MRA. The mechanism for oxygen reduction in the C family cbb 3 cytochrome c oxidases - Implications for the proton pumping stoichiometry. J Inorg Biochem 2019; 203:110866. [PMID: 31706225 DOI: 10.1016/j.jinorgbio.2019.110866] [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: 08/05/2019] [Revised: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 11/16/2022]
Abstract
Cytochrome c oxidases (CcOs) couple the exergonic reduction of molecular oxygen to proton pumping across the membrane in which they are embedded, thereby conserving a significant part of the free energy. The A family CcOs are known to pump four protons per oxygen molecule, while there is no consensus regarding the proton pumping stoichiometry for the C family cbb3 oxidases. Hybrid density functional theory is used here to investigate the catalytic mechanism for oxygen reduction in cbb3 oxidases. A surprising result is that the barrier for O O bond cleavage at the mixed valence reduction level seems to be too high compared to the overall reaction rate of the enzyme. It is therefore suggested that the O O bond is cleaved only after the first proton coupled reduction step, and that this reduction step most likely is not coupled to proton pumping. Furthermore, since the cbb3 oxidases have only one proton channel leading to the active site, it is proposed that the activated EH intermediate, suggested to be responsible for proton pumping in one of the reduction steps in the A family, cannot be involved in the catalytic cycle for cbb3, which results in the lack of proton pumping also in the E to R reduction step. In summary, the calculations indicate that only two protons are pumped per oxygen molecule in cbb3 oxidases. However, more experimental information on this divergent enzyme is needed, e.g. whether the flow of electrons resembles that in the other more well-studied CcO families.
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Affiliation(s)
- Margareta R A Blomberg
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.
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36
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Aarabi M, Soorkia S, Grégoire G, Broquier M, de la Lande A, Soep B, Omidyan R, Shafizadeh N. Water binding to Fe III hemes studied in a cooled ion trap: characterization of a strong 'weak' ligand. Phys Chem Chem Phys 2019; 21:21329-21340. [PMID: 31531442 DOI: 10.1039/c9cp03608c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The interaction of a water molecule with ferric heme-iron protoporphyrin ([PP FeIII]+) has been investigated in the gas phase in an ion trap and studied theoretically by density functional theory. It is found that the interaction of water with ferric heme leads to a stable [PP-FeIII-H2O]+ complex in the intermediate spin state (S = 3/2), in the same state as its unligated [PP-FeIII]+ homologue, without spin crossing during water attachment. Using the Van't Hoff equation, the reaction enthalpy for the formation of a Fe-OH2 bond has been determined for [PP-FeIII-H2O]+ and [PP-FeIII-(H2O)2]+. The corrected binding energy for a single Fe-H2O bond is -12.2 ± 0.6 kcal mol-1, while DFT calculations at the OPBE level yield -11.7 kcal mol-1. The binding energy of the second ligation yielding a six coordinated FeIII atom is decreased with a bond energy of -9 ± 0.9 kcal mol-1, well reproduced by calculations as -7.1 kcal mol-1. However, calculations reveal features of a weaker bond type, such as a rather long Fe-O bond with 2.28 Å for the [PP-FeIII-H2O]+ complex and the absence of a spin change by complexation. Thus despite a strong bond with H2O, the FeIII atom does not show, through theoretical modelling, a strong acceptor character in its half filled 3dz2 orbital. It is also observed that the binding properties of H2O to hemes seem strikingly specific to ferric heme and we have shown, experimentally and theoretically, that the affinity of H2O for protonated heme [H PP-Fe]+, an intermediate between FeIII and FeII, is strongly reduced compared to that for ferric heme.
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Affiliation(s)
- Mohammad Aarabi
- Department of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran
| | - Satchin Soorkia
- ISMO, Université Paris-Sud, CNRS UMR 8214, bat 520, Université Paris-Sud 91405, Orsay Cedex, France.
| | - Gilles Grégoire
- ISMO, Université Paris-Sud, CNRS UMR 8214, bat 520, Université Paris-Sud 91405, Orsay Cedex, France.
| | - Michel Broquier
- ISMO, Université Paris-Sud, CNRS UMR 8214, bat 520, Université Paris-Sud 91405, Orsay Cedex, France. and Centre Laser de l'Université Paris-Sud (CLUPS/LUMAT), Univ. Paris-Sud, CNRS, IOGS, Université Paris-Saclay, F-91405 Orsay, France
| | - Aurélien de la Lande
- Laboratoire de Chimie-Physique, Université Paris Sud, CNRS, UMR 8000, 15, rue Jean Perrin, 91405 Orsay Cedex, France
| | - Benoît Soep
- LIDYL, CEA, CNRS, Université Paris-Saclay, UMR 9222 CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - Reza Omidyan
- Department of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran
| | - Niloufar Shafizadeh
- ISMO, Université Paris-Sud, CNRS UMR 8214, bat 520, Université Paris-Sud 91405, Orsay Cedex, France.
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Kaliakin DS, Fedorov DG, Alexeev Y, Varganov SA. Locating Minimum Energy Crossings of Different Spin States Using the Fragment Molecular Orbital Method. J Chem Theory Comput 2019; 15:6074-6084. [DOI: 10.1021/acs.jctc.9b00641] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Danil S. Kaliakin
- Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557-0216, United States
| | - Dmitri G. Fedorov
- Research Center for Computational Design of Advanced Functional Materials (CD-FMat), National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba 305-8568, Japan
| | - Yuri Alexeev
- Computational Science Division and Argonne Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Sergey A. Varganov
- Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557-0216, United States
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38
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Guo F, Wang Z, Zhao L, Liu W. A proposed method of enantioselectivity analysis for residual chiral PCBs in gas chromatography. CHEMOSPHERE 2019; 229:401-408. [PMID: 31082707 DOI: 10.1016/j.chemosphere.2019.04.162] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/26/2019] [Accepted: 04/21/2019] [Indexed: 06/09/2023]
Abstract
Polychlorinated biphenyls (PCBs) are harmful and persistent organic pollutants. The influence of chiral PCBs acts mainly on the different enantiomer fraction, bioaccumulation and even degradation in environmental media. Solvents and temperatures existed almost everywhere during the analysis of extraction, purification, concentration and detection, which was often underestimated in previous studies. In our study, the configuration stability of the chiral PCBs was examined from solvent and temperature aspects. Transformation phenomena for the analytic stereoisomer monomers of PCB45, PCB95, and PCB149 affected by temperature were observed. We demonstrated that higher inlet temperatures could increase the sensibility for the low-concentration environmental samples, resulting in isomerization of chiral PCBs. Real rice samples were used to verify our analysis method. Combined with density functional theory, we verified the mechanism of isomer conversion with various numbers and sites of the -Cl substituent. PCBs with tetra-ortho substituents (2, 2', 6, 6') were relatively stable and showed the highest rotational barriers (Ea) at approximate 240 kJ mol-1. Others with trio-ortho substituents (2, 2', 6/6') showed Ea from 170 to 190 kJ mol-1, whose enantiomeric fractions would be affected by temperature during the analysis process for environmental detection. The method we developed was a promising means to understand the mechanism of isomerization and to predict stabilities of chiral PCBs.
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Affiliation(s)
- Fangjie Guo
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhongyu Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Lu Zhao
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Weiping Liu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
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39
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Blomberg MRA. Active Site Midpoint Potentials in Different Cytochrome c Oxidase Families: A Computational Comparison. Biochemistry 2019; 58:2028-2038. [PMID: 30892888 DOI: 10.1021/acs.biochem.9b00093] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cytochrome c oxidase (C cO) is the terminal enzyme in the respiratory electron transport chain, reducing molecular oxygen to water. The binuclear active site in C cO comprises a high-spin heme associated with a CuB complex and a redox active tyrosine. The electron transport in the respiratory chain is driven by increasing midpoint potentials of the involved cofactors, resulting in a release of free energy, which is stored by coupling the electron transfer to proton translocation across a membrane, building up an electrochemical gradient. In this context, the midpoint potentials of the active site cofactors in the C cOs are of special interest, since they determine the driving forces for the individual oxygen reduction steps and thereby affect the efficiency of the proton pumping. It has been difficult to obtain useful information on some of these midpoint potentials from experiments. However, since each of the reduction steps in the catalytic cycle of oxygen reduction to water corresponds to the formation of an O-H bond, they can be calculated with a reasonably high accuracy using quantum chemical methods. From the calculated O-H bond strengths, the proton-coupled midpoint potentials of the active site cofactors can be estimated. Using models representing the different families of C cO's (A, B, and C), the calculations give midpoint potentials that should be relevant during catalytic turnover. The calculations also suggest possible explanations for why some experimentally measured potentials deviate significantly from the calculated ones, i.e., for CuB in all oxidase families, and for heme b3 in the C family.
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Affiliation(s)
- Margareta R A Blomberg
- Department of Organic Chemistry, Arrhenius Laboratory , Stockholm University , Stockholm SE-106 91 , Sweden
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40
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Roemelt M, Pantazis DA. Multireference Approaches to Spin‐State Energetics of Transition Metal Complexes Utilizing the Density Matrix Renormalization Group. ADVANCED THEORY AND SIMULATIONS 2019. [DOI: 10.1002/adts.201800201] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Michael Roemelt
- Lehrstuhl für Theoretische ChemieRuhr‐Universität Bochum 44780 Bochum Germany
- Max‐Planck‐Institut für Kohlenforschung Kaiser‐Wilhelm‐Platz 1 45470 Mülheim an der Ruhr Germany
| | - Dimitrios A. Pantazis
- Max‐Planck‐Institut für Kohlenforschung Kaiser‐Wilhelm‐Platz 1 45470 Mülheim an der Ruhr Germany
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41
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Zhang Q, Ji S, Chai L, Yang F, Zhao M, Liu W, Schüürmann G, Ji L. Metabolic Mechanism of Aryl Phosphorus Flame Retardants by Cytochromes P450: A Combined Experimental and Computational Study on Triphenyl Phosphate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:14411-14421. [PMID: 30421920 DOI: 10.1021/acs.est.8b03965] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Understanding metabolic mechanisms is critical and remains a difficult task in the risk assessment of emerging pollutants. Triphenyl phosphate (TPHP), a widely used aryl phosphorus flame retardant (aryl-PFR), has been frequently detected in the environment, and its major metabolite was considered as diphenyl phosphate (DPHP). However, knowledge of the mechanism for TPHP leading to DPHP and other metabolites is lacking. Our in vitro study shows that TPHP is metabolized into its diester metabolite DPHP and mono- and dihydroxylated metabolites by cytochromes P450 (CYP) in human liver microsomes, while CYP1A2 and CYP2E1 isoforms are mainly involved in such processes. Molecular docking gives the conformation for TPHP binding with the active species Compound I (an iron IV-oxo heme cation radical) in specific CYP isoforms, showing that the aromatic ring of TPHP is likely to undergo metabolism. Quantum chemical calculations have shown that the dominant reaction channel is the O-addition of Compound I onto the aromatic ring of TPHP, followed by a hydrogen-shuttle mechanism leading to ortho-hydroxy-TPHP as the main monohydroxylated metabolite; the subsequent H-abstraction-OH-rebound reaction acting on ortho-hydroxy-TPHP yields the meta- and ipso-position quinol intermediates, while the former of which can be metabolized into dihydroxy-TPHP by fast protonation, and the latter species needs to go through type-I ipso-substitution and fast protonation to be evolved into DPHP. We envision that the identified mechanisms may give inspiration for studying the metabolism of several other aryl-PFRs by CYP.
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Affiliation(s)
- Quan Zhang
- College of Environment , Zhejiang University of Technology , Hangzhou 310032 , China
| | - Shujing Ji
- College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Lihong Chai
- College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Fangxing Yang
- College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Meirong Zhao
- College of Environment , Zhejiang University of Technology , Hangzhou 310032 , China
| | - Weiping Liu
- College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Gerrit Schüürmann
- UFZ Department of Ecological Chemistry , Helmholtz Centre for Environmental Research , Permoserstrasse 15 , 04318 Leipzig , Germany
- Institute for Organic Chemistry , Technical University Bergakademie Freiberg , Leipziger Strasse 29 , 09596 Freiberg , Germany
| | - Li Ji
- College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , China
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42
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Ma G, Yu H, Xu T, Wei X, Chen J, Lin H, Schüürmann G. Computational Insight into the Activation Mechanism of Carcinogenic N'-Nitrosonornicotine (NNN) Catalyzed by Cytochrome P450. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11838-11847. [PMID: 30209943 DOI: 10.1021/acs.est.8b02795] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Tobacco-specific N'-nitrosonornicotine (NNN), a genotoxic nitrosamine classified as Group 1 carcinogen, is also present in atmospheric particulate matter and has even been detected as a new disinfection byproduct in wastewaters. NNN generally requires metabolic activation by cytochrome P450 enzymes to exert its genotoxicity, but the respective biotransformation pathways have not been described in detail. In this work, we performed density functional theory (DFT) calculations to unravel possible NNN activation pathways including α-hydroxylation, β-hydroxylation, pyridine N-oxidation, and norcotinine formation. The results reveal an initial rate-determining Hα-atom abstraction step for α-hydroxylation, followed by an unexpected kinetic competition between denitrosation and OH rebound, leading to ( iso-)myosmine as a detoxified product and α-hydroxyNNNs as the precursor of carcinogenic diazohydroxides, respectively. Further detoxification routes are given by β-hydroxylation with relative high reaction barrier and N-oxidation with comparable barrier to the toxifying α-hydroxylation. Moreover, we show for the first time how norcotinine can be generated as a minor NNN metabolite that is formed from iso-myosmine through a unique porphyrin-assisted H atom 1,2-transfer mechanism. These results demonstrate that the carcinogenic potential of NNN is subject to a kinetic competition between activating and deactivating metabolic routes, and identify respective biomarkers to inform about the individual risk associated with NNN exposure.
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Affiliation(s)
- Guangcai Ma
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Haiying Yu
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Ting Xu
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Xiaoxuan Wei
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Jianrong Chen
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Hongjun Lin
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Gerrit Schüürmann
- UFZ Department of Ecological Chemistry , Helmholtz Centre for Environmental Research , Permoserstrasse 15 , 04318 , Leipzig , Germany
- Institute of Organic Chemistry , Technical University Bergakademie Freiberg , Leipzig Strasse 29 , 09596 Freiberg , Germany
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43
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Blomberg MRA, Ädelroth P. Mechanisms for enzymatic reduction of nitric oxide to nitrous oxide - A comparison between nitric oxide reductase and cytochrome c oxidase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:1223-1234. [PMID: 30248312 DOI: 10.1016/j.bbabio.2018.09.368] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/23/2018] [Accepted: 09/17/2018] [Indexed: 12/22/2022]
Abstract
Cytochrome c oxidases (CcO) reduce O2 to H2O in the respiratory chain of mitochondria and many aerobic bacteria. In addition, some species of CcO can also reduce NO to N2O and water while others cannot. Here, the mechanism for NO-reduction in CcO is investigated using quantum mechanical calculations. Comparison is made to the corresponding reaction in a "true" cytochrome c-dependent NO reductase (cNOR). The calculations show that in cNOR, where the reduction potentials are low, the toxic NO molecules are rapidly reduced, while the higher reduction potentials in CcO lead to a slower or even impossible reaction, consistent with experimental observations. In both enzymes the reaction is initiated by addition of two NO molecules to the reduced active site, forming a hyponitrite intermediate. In cNOR, N2O can then be formed using only the active-site electrons. In contrast, in CcO, one proton-coupled reduction step most likely has to occur before N2O can be formed, and furthermore, proton transfer is most likely rate-limiting. This can explain why different CcO species with the same heme a3-Cu active site differ with respect to NO reduction efficiency, since they have a varying number and/or properties of proton channels. Finally, the calculations also indicate that a conserved active site valine plays a role in reducing the rate of NO reduction in CcO.
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Affiliation(s)
- Margareta R A Blomberg
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden.
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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44
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Ji L, Ji S, Wang C, Kepp KP. Molecular Mechanism of Alternative P450-Catalyzed Metabolism of Environmental Phenolic Endocrine-Disrupting Chemicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:4422-4431. [PMID: 29490136 DOI: 10.1021/acs.est.8b00601] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Understanding the bioactivation mechanisms to predict toxic metabolites is critical for risk assessment of phenolic endocrine-disrupting chemicals (EDCs). One mechanism involves ipso-substitution, which may contribute to the total turnover of phenolic EDCs, yet the detailed mechanism and its relationship with other mechanisms are unknown. We used density functional theory to investigate the P450-catalyzed ipso-substitution mechanism of the prominent xenoestrogen bisphenol A. The ipso-substitution proceeds via H-abstraction from bisphenol A by Compound I, followed by essentially barrierless OH-rebound onto the ipso-position forming a quinol, which can spontaneously decompose into the carbocation and hydroquinone. This carbocation can further evolve into the highly estrogenic hydroxylated and dimer-type metabolites. The H-abstraction/OH-rebound reaction mechanism has been verified as a general reaction mode for many other phenolic EDCs, such as bisphenol analogues, alkylphenols and chlorophenols. The identified mechanism enables us to effectively distinguish between type I (eliminating-substituent as anion) and type II (eliminating-substituent as cation) ipso-substitution in various phenolic EDCs. We envision that the identified pathways will be applicable for prediction of metabolites from phenolic EDCs whose fate are affected by this alternative type of P450 reactivity, and accordingly enable the screening of these metabolites for endocrine-disrupting activity.
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Affiliation(s)
- Li Ji
- College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , P. R. China
- UFZ Department of Ecological Chemistry , Helmholtz Centre for Environmental Research , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Shujing Ji
- College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , P. R. China
| | - Chenchen Wang
- College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , P. R. China
| | - Kasper P Kepp
- DTU Chemistry , Technical University of Denmark , Building 206 , Kongens Lyngby , DK-2800 , Denmark
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45
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Lábas A, Menyhárd DK, Harvey JN, Oláh J. First Principles Calculation of the Reaction Rates for Ligand Binding to Myoglobin: The Cases of NO and CO. Chemistry 2018; 24:5350-5358. [PMID: 29285802 DOI: 10.1002/chem.201704867] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Indexed: 12/12/2022]
Abstract
Ligand binding by proteins is among the most fundamental processes in nature. Among these processes the binding of small gas molecules, such as O2 , CO and NO to heme proteins has traditionally received vivid interest, which was further boosted by their recently recognized significant role in gas sensing in the body. At the heart of the binding of these ligands to the heme group is the spinforbidden reaction between high-spin iron(II) and the ligand yielding a low-spin adduct. We use computational means to address the complete mechanism of CO and NO binding by myoglobin. Considering that it involves several steps occurring on different time scales, molecular dynamics simulations were performed to address the diffusion of the ligand through the enzyme, and DFT calculations in combination with statistical rate calculation to investigate the spin-forbidden reaction. The calculations yielded rate constants in qualitative agreement with experiments and revealed that the bottleneck of NO and CO binding is different; for NO, diffusion was found to be rate-limiting, whereas for CO, the spin-forbidden step is the slowest.
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Affiliation(s)
- Anikó Lábas
- Department of Inorganic Chemistry, Budapest University of Technology and Economics, H-1111, Budapest, Szent Gellért tér 4., Hungary
| | - Dóra K Menyhárd
- MTA-ELTE Protein Modelling Research Group, H-1117, Budapest, Pázmány Péter st. 1/A, Hungary
| | - Jeremy N Harvey
- Department of Chemistry, KU Leuven, B-3001, Leuven Celestijnenlaan 200F- box 2404, Belgium
| | - Julianna Oláh
- Department of Inorganic Chemistry, Budapest University of Technology and Economics, H-1111, Budapest, Szent Gellért tér 4., Hungary
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46
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Phung QM, Pierloot K. The dioxygen adducts of iron and manganese porphyrins: electronic structure and binding energy. Phys Chem Chem Phys 2018; 20:17009-17019. [DOI: 10.1039/c8cp03078b] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The electronic structures of adducts of O2 and metal porphyrins were thoroughly investigated by highly accurate DMRG-CASPT2.
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47
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Benabbas A, Sun Y, Poulos TL, Champion PM. Ultrafast CO Kinetics in Heme Proteins: Adiabatic Ligand Binding and Heavy Atom Tunneling. J Am Chem Soc 2017; 139:15738-15747. [PMID: 28984134 DOI: 10.1021/jacs.7b07507] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The ultrafast kinetics of CO rebinding to carbon monoxide oxidation activator protein (ChCooA) are measured over a wide temperature range and compared with the kinetics of CO binding in other heme systems such as myoglobin (Mb) and hemoglobin (Hb). The Arrhenius prefactor for CO binding to ChCooA and protoheme (∼1011 s-1) is similar to what is found for spin-allowed NO binding to heme proteins and is several orders of magnitude larger than the prefactor of Mb and Hb (∼109 s-1). This indicates that the CO binding reaction is adiabatic, in contrast to the commonly held view that it is nonadiabatic due to spin-forbidden (ΔS = 2) selection rules. Under the adiabatic condition, entropic factors, rather than spin-selection rules, are the source of the reduced Arrhenius prefactors associated with CO binding in Mb and Hb. The kinetic response of ChCooA-CO is nonexponential at all temperatures, including 298 K, and is described quantitatively using a distribution of enthalpic rebinding barriers associated with heterogeneity in the heme doming conformation. Above the solvent glass transition (Tg ∼ 180 K), the rebinding progress slows as temperature increases, and this is ascribed to an evolution of the distribution toward increased heme doming and larger enthalpic barriers. Between Tg and ∼60 K, the nonexponential rebinding slows down as the temperature is lowered and the survival fraction follows the predictions expected for a quenched barrier distribution. Below ∼60 K the rebinding kinetics do not follow these predictions unless quantum mechanical tunneling along the heme doming coordinate is also included as an active channel for CO binding.
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Affiliation(s)
- Abdelkrim Benabbas
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University , Boston, Massachusetts 02115, United States
| | - Yuhan Sun
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University , Boston, Massachusetts 02115, United States
| | - Thomas L Poulos
- Departments of Molecular Biology and Biochemistry, Chemistry, and Pharmaceutical Sciences, University of California , Irvine, California 92697, United States
| | - Paul M Champion
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University , Boston, Massachusetts 02115, United States
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Blomberg MRA, Ädelroth P. The mechanism for oxygen reduction in cytochrome c dependent nitric oxide reductase (cNOR) as obtained from a combination of theoretical and experimental results. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:884-894. [PMID: 28801051 DOI: 10.1016/j.bbabio.2017.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/29/2017] [Accepted: 08/05/2017] [Indexed: 11/30/2022]
Abstract
Bacterial NO-reductases (NOR) belong to the heme-copper oxidase (HCuO) superfamily, in which most members are O2-reducing, proton-pumping enzymes. This study is one in a series aiming to elucidate the reaction mechanisms of the HCuOs, including the mechanisms for cellular energy conservation. One approach towards this goal is to compare the mechanisms for the different types of HCuOs, cytochrome c oxidase (CcO) and NOR, reducing the two substrates O2 and NO. Specifically in this study, we describe the mechanism for oxygen reduction in cytochrome c dependent NOR (cNOR). Hybrid density functional calculations were performed on large cluster models of the cNOR binuclear active site. Our results are used, together with published experimental information, to construct a free energy profile for the entire catalytic cycle. Although the overall reaction is quite exergonic, we show that during the reduction of molecular oxygen in cNOR, two of the reduction steps are endergonic with high barriers for proton uptake, which is in contrast to oxygen reduction in CcO, where all reduction steps are exergonic. This difference between the two enzymes is suggested to be important for their differing capabilities for energy conservation. An additional result from this study is that at least three of the four reduction steps are initiated by proton transfer to the active site, which is in contrast to CcO, where electrons always arrive before the protons to the active site. The roles of the non-heme metal ion and the redox-active tyrosine in the active site are also discussed.
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Affiliation(s)
- Margareta R A Blomberg
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden.
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University, Stockholm SE-106 91, Sweden
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Freitag L, Knecht S, Angeli C, Reiher M. Multireference Perturbation Theory with Cholesky Decomposition for the Density Matrix Renormalization Group. J Chem Theory Comput 2017; 13:451-459. [PMID: 28094988 PMCID: PMC5312874 DOI: 10.1021/acs.jctc.6b00778] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Indexed: 01/05/2023]
Abstract
We present a second-order N-electron valence state perturbation theory (NEVPT2) based on a density matrix renormalization group (DMRG) reference wave function that exploits a Cholesky decomposition of the two-electron repulsion integrals (CD-DMRG-NEVPT2). With a parameter-free multireference perturbation theory approach at hand, the latter allows us to efficiently describe static and dynamic correlation in large molecular systems. We demonstrate the applicability of CD-DMRG-NEVPT2 for spin-state energetics of spin-crossover complexes involving calculations with more than 1000 atomic basis functions. We first assess, in a study of a heme model, the accuracy of the strongly and partially contracted variant of CD-DMRG-NEVPT2 before embarking on resolving a controversy about the spin ground state of a cobalt tropocoronand complex.
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Affiliation(s)
- Leon Freitag
- ETH
Zürich, Laboratorium für
Physikalische Chemie, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Stefan Knecht
- ETH
Zürich, Laboratorium für
Physikalische Chemie, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Celestino Angeli
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università
di Ferrara, Via Fossato
di Mortara 17, 44121 Ferrara, Italy
| | - Markus Reiher
- ETH
Zürich, Laboratorium für
Physikalische Chemie, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
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