1
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Dias AHS, Cao Y, Skaf MS, de Visser SP. Machine learning-aided engineering of a cytochrome P450 for optimal bioconversion of lignin fragments. Phys Chem Chem Phys 2024; 26:17577-17587. [PMID: 38884162 DOI: 10.1039/d4cp01282h] [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: 06/18/2024]
Abstract
Using machine learning, molecular dynamics simulations, and density functional theory calculations we gain insight into the selectivity patterns of substrate activation by the cytochromes P450. In nature, the reactions catalyzed by the P450s lead to the biodegradation of xenobiotics, but recent work has shown that fungi utilize P450s for the activation of lignin fragments, such as monomer and dimer units. These fragments often are the building blocks of valuable materials, including drug molecules and fragrances, hence a highly selective biocatalyst that can produce these compounds in good yield with high selectivity would be an important step in biotechnology. In this work a detailed computational study is reported on two reaction channels of two P450 isozymes, namely the O-deethylation of guaethol by CYP255A and the O-demethylation versus aromatic hydroxylation of p-anisic acid by CYP199A4. The studies show that the second-coordination sphere plays a major role in substrate binding and positioning, heme access, and in the selectivity patterns. Moreover, the local environment affects the kinetics of the reaction through lowering or raising barrier heights. Furthermore, we predict a site-selective mutation for highly specific reaction channels for CYP199A4.
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Affiliation(s)
- Artur Hermano Sampaio Dias
- Manchester Institute of Biotechnology and Department of Chemical Engineering, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
- Institute of Chemistry and Centre for Computing in Engineering & Sciences, University of Campinas, Campinas, SP 13083-861, Brazil
| | - Yuanxin Cao
- Manchester Institute of Biotechnology and Department of Chemical Engineering, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
| | - Munir S Skaf
- Institute of Chemistry and Centre for Computing in Engineering & Sciences, University of Campinas, Campinas, SP 13083-861, Brazil
| | - Sam P de Visser
- Manchester Institute of Biotechnology and Department of Chemical Engineering, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
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2
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Ali HS, de Visser SP. QM/MM Study Into the Mechanism of Oxidative C=C Double Bond Cleavage by Lignostilbene-α,β-Dioxygenase. Chemistry 2024; 30:e202304172. [PMID: 38373118 DOI: 10.1002/chem.202304172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/29/2024] [Accepted: 02/19/2024] [Indexed: 02/21/2024]
Abstract
The enzymatic biosynthesis of fragrance molecules from lignin fragments is an important reaction in biotechnology for the sustainable production of fine chemicals. In this work we investigated the biosynthesis of vanillin from lignostilbene by a nonheme iron dioxygenase using QM/MM and tested several suggested proposals via either an epoxide or dioxetane intermediate. Binding of dioxygen to the active site of the protein results in the formation of an iron(II)-superoxo species with lignostilbene cation radical. The dioxygenase mechanism starts with electrophilic attack of the terminal oxygen atom of the superoxo group on the central C=C bond of lignostilbene, and the second-coordination sphere effects in the substrate binding pocket guide the reaction towards dioxetane formation. The computed mechanism is rationalized with thermochemical cycles and valence bond schemes that explain the electron transfer processes during the reaction mechanism. Particularly, the polarity of the protein and the local electric field and dipole moments enable a facile electron transfer and an exergonic dioxetane formation pathway.
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Affiliation(s)
- Hafiz Saqib Ali
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Sam P de Visser
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
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3
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Klemencic E, Brewster RC, Ali HS, Richardson JM, Jarvis AG. Using BpyAla to generate copper artificial metalloenzymes: a catalytic and structural study. Catal Sci Technol 2024; 14:1622-1632. [PMID: 38505507 PMCID: PMC10946309 DOI: 10.1039/d3cy01648j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/25/2024] [Indexed: 03/21/2024]
Abstract
Artificial metalloenzymes (ArMs) have emerged as a promising avenue in the field of biocatalysis, offering new reactivity. However, their design remains challenging due to the limited understanding of their protein dynamics and how the introduced cofactors alter the protein scaffold structure. Here we present the structures and catalytic activity of novel copper ArMs capable of (R)- or (S)-stereoselective control, utilizing a steroid carrier protein (SCP) scaffold. To incorporate 2,2'-bipyridine (Bpy) into SCP, two distinct strategies were employed: either Bpy was introduced as an unnatural amino acid (2,2'-bipyridin-5-yl)alanine (BpyAla) using amber stop codon expression or via bioconjugation of bromomethyl-Bpy to cysteine residues. The resulting ArMs proved to be effective at catalysing an enantioselective Friedel-Crafts reaction with SCP_Q111BpyAla achieving the best selectivity with an enantioselectivity of 72% ee (S). Interestingly, despite using the same protein scaffold, different attachment strategies for Bpy at the same residue (Q111) led to a switch in the enantiopreference of the ArM. X-ray crystal structures of SCP_Q111CBpy and SCP_Q111BpyAla ArMs with bound Cu(ii) ions unveiled crucial differences in the orientation of the catalytic centre. Combining structural information, alanine scanning studies, and computational analysis shed light on the distinct active sites of the ArMs, clarifying that these active sites stabilise the nucleophilic substrate on different sides of the electrophile leading to the observed switch in enantioselectivity. This work underscores the importance of integrating structural studies with catalytic screening to unravel the intricacies of ArM behaviour and facilitate their development for targeted applications in biocatalysis.
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Affiliation(s)
- E Klemencic
- EaStCHEM School of Chemistry, University of Edinburgh Joseph Black Building David Brewster Road The King's Buildings Edinburgh EH9 3FJ UK
| | - R C Brewster
- EaStCHEM School of Chemistry, University of Edinburgh Joseph Black Building David Brewster Road The King's Buildings Edinburgh EH9 3FJ UK
| | - H S Ali
- EaStCHEM School of Chemistry, University of Edinburgh Joseph Black Building David Brewster Road The King's Buildings Edinburgh EH9 3FJ UK
| | - J M Richardson
- School of Biological Sciences, University of Edinburgh Swann Building Edinburgh EH9 3BF UK
| | - A G Jarvis
- EaStCHEM School of Chemistry, University of Edinburgh Joseph Black Building David Brewster Road The King's Buildings Edinburgh EH9 3FJ UK
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4
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Zhu C, D’Agostino C, de Visser SP. CO 2 Reduction by an Iron(I) Porphyrinate System: Effect of Hydrogen Bonding on the Second Coordination Sphere. Inorg Chem 2024; 63:4474-4481. [PMID: 38408891 PMCID: PMC10934816 DOI: 10.1021/acs.inorgchem.3c04246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 02/28/2024]
Abstract
Transforming CO2 into valuable materials is an important reaction in catalysis, especially because CO2 concentrations in the atmosphere have been growing steadily due to extensive fossil fuel usage. From an environmental perspective, reduction of CO2 to valuable materials should be catalyzed by an environmentally benign catalyst and avoid the use of heavy transition-metal ions. In this work, we present a computational study into a novel iron(I) porphyrin catalyst for CO2 reduction, namely, with a tetraphenylporphyrin ligand and analogues. In particular, we investigated iron(I) tetraphenylporphyrin with one of the meso-phenyl groups substituted with o-urea, p-urea, or o-2-amide groups. These substituents can provide hydrogen-bonding interactions in the second coordination sphere with bound ligands and assist with proton relay. Furthermore, our studies investigated bicarbonate and phenol as stabilizers and proton donors in the reaction mechanism. Potential energy landscapes for double protonation of iron(I) porphyrinate with bound CO2 are reported. The work shows that the bicarbonate bridges the urea/amide groups to the CO2 and iron center and provides a tight bonding pattern with strong hydrogen-bonding interactions that facilitates easy proton delivery and reduction of CO2. Specifically, bicarbonate provides a low-energy proton shuttle mechanism to form CO and water efficiently. Furthermore, the o-urea group locks bicarbonate and CO2 in a tight orientation and helps with ideal proton transfer, while there is more mobility and lesser stability with an o-amide group in that position instead. Our calculations show that the o-urea group leads to reduction in proton-transfer barriers, in line with experimental observation. We then applied electric-field-effect calculations to estimate the environmental effects on the two proton-transfer steps in the reaction. These calculations describe the perturbations that enhance the driving forces for the proton-transfer steps and have been used to make predictions about how the catalysts can be further engineered for more enhanced CO2 reduction processes.
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Affiliation(s)
- Chengxu Zhu
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
| | - Carmine D’Agostino
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
- Dipartimento
di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Alma Mater Studiorum−Università di Bologna, Via Terracini 28, 40131 Bologna, Italy
| | - Sam P. de Visser
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
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5
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Ali HS, de Visser SP. Catalytic divergencies in the mechanism of L-arginine hydroxylating nonheme iron enzymes. Front Chem 2024; 12:1365494. [PMID: 38406558 PMCID: PMC10884159 DOI: 10.3389/fchem.2024.1365494] [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: 01/04/2024] [Accepted: 01/22/2024] [Indexed: 02/27/2024] Open
Abstract
Many enzymes in nature utilize a free arginine (L-Arg) amino acid to initiate the biosynthesis of natural products. Examples include nitric oxide synthases, which generate NO from L-Arg for blood pressure control, and various arginine hydroxylases involved in antibiotic biosynthesis. Among the groups of arginine hydroxylases, several enzymes utilize a nonheme iron(II) active site and let L-Arg react with dioxygen and α-ketoglutarate to perform either C3-hydroxylation, C4-hydroxylation, C5-hydroxylation, or C4-C5-desaturation. How these seemingly similar enzymes can react with high specificity and selectivity to form different products remains unknown. Over the past few years, our groups have investigated the mechanisms of L-Arg-activating nonheme iron dioxygenases, including the viomycin biosynthesis enzyme VioC, the naphthyridinomycin biosynthesis enzyme NapI, and the streptothricin biosynthesis enzyme OrfP, using computational approaches and applied molecular dynamics, quantum mechanics on cluster models, and quantum mechanics/molecular mechanics (QM/MM) approaches. These studies not only highlight the differences in substrate and oxidant binding and positioning but also emphasize on electronic and electrostatic differences in the substrate-binding pockets of the enzymes. In particular, due to charge differences in the active site structures, there are changes in the local electric field and electric dipole moment orientations that either strengthen or weaken specific substrate C-H bonds. The local field effects, therefore, influence and guide reaction selectivity and specificity and give the enzymes their unique reactivity patterns. Computational work using either QM/MM or density functional theory (DFT) on cluster models can provide valuable insights into catalytic reaction mechanisms and produce accurate and reliable data that can be used to engineer proteins and synthetic catalysts to perform novel reaction pathways.
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Affiliation(s)
- Hafiz Saqib Ali
- Chemistry Research Laboratory, Department of Chemistry and the INEOS Oxford Institute for Antimicrobial Research, University of Oxford, Oxford, United Kingdom
| | - Sam P. de Visser
- Manchester Institute of Biotechnology and Department of Chemical Engineering, The University of Manchester, Manchester, United Kingdom
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6
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Santos SFG, Bommareddy RR, Black GW, Singh W. Impact of the T296S mutation in P450 GcoA for aryl-O-demethylation: a QM/MM study. Front Chem 2024; 11:1327398. [PMID: 38283898 PMCID: PMC10811788 DOI: 10.3389/fchem.2023.1327398] [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: 10/24/2023] [Accepted: 12/15/2023] [Indexed: 01/30/2024] Open
Abstract
Lignin, a complex plant cell wall component, holds promise as a renewable aromatic carbon feedstock. p-Vanillin is a key product of lignin depolymerization and a precursor of protocatechuic acid (PCA) that has tremendous potential for biofuel production. While the GcoAB enzyme, native to Amycolatopsis sp., naturally catalyzes aryl-O-demethylation toward guaiacol, recent research introduced a single mutation, T296S, into the GcoAP450 enzyme, enabling it to catalyze aryl-O-demethylation of p-vanillin. This structural modification increases the efficiency of GcoAP450 for the natural substrate while being active for p-vanillin. This study reveals the increased flexibility of p-vanillin and its ability to adapt a favorable conformation by aligning the methoxy group in close proximity to Fe(IV) = O of Cpd I in the active site of the T296S variant. The QM/MM calculations in accordance with the experimental data validated that the rate-limiting step for the oxidation of p-vanillin is hydrogen atom abstraction and provided a detailed geometric structure of stationary and saddle points for the oxidation of p-vanillin.
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Affiliation(s)
- Sonia F. G. Santos
- Hub for Biotechnology in Build Environment, Newcastle upon Tyne, United Kingdom
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Rajesh Reddy Bommareddy
- Hub for Biotechnology in Build Environment, Newcastle upon Tyne, United Kingdom
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Gary W. Black
- Hub for Biotechnology in Build Environment, Newcastle upon Tyne, United Kingdom
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Warispreet Singh
- Hub for Biotechnology in Build Environment, Newcastle upon Tyne, United Kingdom
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
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7
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Li X, Gluth A, Feng S, Qian WJ, Yang B. Harnessing redox proteomics to study metabolic regulation and stress response in lignin-fed Rhodococci. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:180. [PMID: 37986172 PMCID: PMC10662689 DOI: 10.1186/s13068-023-02424-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 11/02/2023] [Indexed: 11/22/2023]
Abstract
BACKGROUND Rhodococci are studied for their bacterial ligninolytic capabilities and proclivity to accumulate lipids. Lignin utilization is a resource intensive process requiring a variety of redox active enzymes and cofactors for degradation as well as defense against the resulting toxic byproducts and oxidative conditions. Studying enzyme expression and regulation between carbon sources will help decode the metabolic rewiring that stymies lignin to lipid conversion in these bacteria. Herein, a redox proteomics approach was applied to investigate a fundamental driver of carbon catabolism and lipid anabolism: redox balance. RESULTS A consortium of Rhodococcus strains was employed in this study given its higher capacity for lignin degradation compared to monocultures. This consortium was grown on glucose vs. lignin under nitrogen limitation to study the importance of redox balance as it relates to nutrient availability. A modified bottom-up proteomics workflow was harnessed to acquire a general relationship between protein abundance and protein redox states. Global proteomics results affirm differential expression of enzymes involved in sugar metabolism vs. those involved in lignin degradation and aromatics metabolism. As reported previously, several enzymes in the lipid biosynthetic pathways were downregulated, whereas many involved in β-oxidation were upregulated. Interestingly, proteins involved in oxidative stress response were also upregulated perhaps in response to lignin degradation and aromatics catabolism, which require oxygen and reactive oxygen species and generate toxic byproducts. Enzymes displaying little-to-no change in abundance but differences in redox state were observed in various pathways for carbon utilization (e.g., β‑ketoadipate pathway), lipid metabolism, as well as nitrogen metabolism (e.g., purine scavenging/synthesis), suggesting potential mechanisms of redox-dependent regulation of metabolism. CONCLUSIONS Efficient lipid production requires a steady carbon and energy flux while balancing fundamental requirements for enzyme production and cell maintenance. For lignin, we theorize that this balance is difficult to establish due to resource expenditure for enzyme production and stress response. This is supported by significant changes to protein abundances and protein cysteine oxidation in various metabolic pathways and redox processes.
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Affiliation(s)
- Xiaolu Li
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Austin Gluth
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA
| | - Song Feng
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Wei-Jun Qian
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Bin Yang
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA.
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
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8
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Zhang Y, Mokkawes T, de Visser SP. Insights into Cytochrome P450 Enzyme Catalyzed Defluorination of Aromatic Fluorides. Angew Chem Int Ed Engl 2023; 62:e202310785. [PMID: 37641517 DOI: 10.1002/anie.202310785] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
Density functional calculations establish a novel mechanism of aromatic defluorination by P450 Compound I. This is achieved via either an initial epoxide intermediate or through a 1,2-fluorine shift in an electrophilic intermediate, which highlights that the P450s can defluorinate fluoroarenes. However, in the absence of a proton donor a strong Fe-F bond can be obtained as shown from the calculations.
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Affiliation(s)
- Yi Zhang
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M17DN, UK
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Thirakorn Mokkawes
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M17DN, UK
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Sam P de Visser
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M17DN, UK
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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9
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Mokkawes T, De Visser T, Cao Y, De Visser SP. Melatonin Activation by Human Cytochrome P450 Enzymes: A Comparison between Different Isozymes. Molecules 2023; 28:6961. [PMID: 37836804 PMCID: PMC10574541 DOI: 10.3390/molecules28196961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/30/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
Cytochrome P450 enzymes in the human body play a pivotal role in both the biosynthesis and the degradation of the hormone melatonin. Melatonin plays a key role in circadian rhythms in the body, but its concentration is also linked to mood fluctuations as well as emotional well-being. In the present study, we present a computational analysis of the binding and activation of melatonin by various P450 isozymes that are known to yield different products and product distributions. In particular, the P450 isozymes 1A1, 1A2, and 1B1 generally react with melatonin to provide dominant aromatic hydroxylation at the C6-position, whereas the P450 2C19 isozyme mostly provides O-demethylation products. To gain insight into the origin of these product distributions of the P450 isozymes, we performed a comprehensive computational study of P450 2C19 isozymes and compared our work with previous studies on alternative isozymes. The work covers molecular mechanics, molecular dynamics and quantum mechanics approaches. Our work highlights major differences in the size and shape of the substrate binding pocket amongst the different P450 isozymes. Consequently, substrate binding and positioning in the active site varies substantially within the P450 isozymes. Thus, in P450 2C19, the substrate is oriented with its methoxy group pointing towards the heme, and therefore reacts favorably through hydrogen atom abstraction, leading to the production of O-demethylation products. On the other hand, the substrate-binding pockets in P450 1A1, 1A2, and 1B1 are tighter, direct the methoxy group away from the heme, and consequently activate an alternative site and lead to aromatic hydroxylation instead.
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Affiliation(s)
| | | | | | - Sam P. De Visser
- Department of Chemical Engineering, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
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10
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Mokkawes T, de Visser SP. Melatonin Activation by Cytochrome P450 Isozymes: How Does CYP1A2 Compare to CYP1A1? Int J Mol Sci 2023; 24:ijms24043651. [PMID: 36835057 PMCID: PMC9959256 DOI: 10.3390/ijms24043651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/09/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Cytochrome P450 enzymes are versatile enzymes found in most biosystems that catalyze mono-oxygenation reactions as a means of biosynthesis and biodegradation steps. In the liver, they metabolize xenobiotics, but there are a range of isozymes with differences in three-dimensional structure and protein chain. Consequently, the various P450 isozymes react with substrates differently and give varying product distributions. To understand how melatonin is activated by the P450s in the liver, we did a thorough molecular dynamics and quantum mechanics study on cytochrome P450 1A2 activation of melatonin forming 6-hydroxymelatonin and N-acetylserotonin products through aromatic hydroxylation and O-demethylation pathways, respectively. We started from crystal structure coordinates and docked substrate into the model, and obtained ten strong binding conformations with the substrate in the active site. Subsequently, for each of the ten substrate orientations, long (up to 1 μs) molecular dynamics simulations were run. We then analyzed the orientations of the substrate with respect to the heme for all snapshots. Interestingly, the shortest distance does not correspond to the group that is expected to be activated. However, the substrate positioning gives insight into the protein residues it interacts with. Thereafter, quantum chemical cluster models were created and the substrate hydroxylation pathways calculated with density functional theory. These relative barrier heights confirm the experimental product distributions and highlight why certain products are obtained. We make a detailed comparison with previous results on CYP1A1 and identify their reactivity differences with melatonin.
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Affiliation(s)
- Thirakorn Mokkawes
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Sam P. de Visser
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
- Correspondence:
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11
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Hermano Sampaio Dias A, Yadav R, Mokkawes T, Kumar A, Skaf MS, Sastri CV, Kumar D, de Visser SP. Biotransformation of Bisphenol by Human Cytochrome P450 2C9 Enzymes: A Density Functional Theory Study. Inorg Chem 2023; 62:2244-2256. [PMID: 36651185 PMCID: PMC9923688 DOI: 10.1021/acs.inorgchem.2c03984] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Bisphenol A (BPA, 2,2-bis-(4-hydroxyphenyl)propane) is used as a precursor in the synthesis of polycarbonate and epoxy plastics; however, its availability in the environment is causing toxicity as an endocrine-disrupting chemical. Metabolism of BPA and their analogues (substitutes) is generally performed by liver cytochrome P450 enzymes and often leads to a mixture of products, and some of those are toxic. To understand the product distributions of P450 activation of BPA, we have performed a computational study into the mechanisms and reactivities using large model structures of a human P450 isozyme (P450 2C9) with BPA bound. Density functional theory (DFT) calculations on mechanisms of BPA activation by a P450 compound I model were investigated, leading to a number of possible products. The substrate-binding pocket is tight, and as a consequence, aliphatic hydroxylation is not feasible as the methyl substituents of BPA cannot reach compound I well due to constraints of the substrate-binding pocket. Instead, we find low-energy pathways that are initiated with phenol hydrogen atom abstraction followed by OH rebound to the phenolic ortho- or para-position. The barriers of para-rebound are well lower in energy than those for ortho-rebound, and consequently, our P450 2C9 model predicts dominant hydroxycumyl alcohol products. The reactions proceed through two-state reactivity on competing doublet and quartet spin state surfaces. The calculations show fast and efficient substrate activation on a doublet spin state surface with a rate-determining electrophilic addition step, while the quartet spin state surface has multiple high-energy barriers that can also lead to various side products including C4-aromatic hydroxylation. This work shows that product formation is more feasible on the low spin state, while the physicochemical properties of the substrate govern barrier heights of the rate-determining step of the reaction. Finally, the importance of the second-coordination sphere is highlighted that determines the product distributions and guides the bifurcation pathways.
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Affiliation(s)
- Artur Hermano Sampaio Dias
- Manchester
Institute of Biotechnology and Department of Chemical Engineering, The University of Manchester, 131 Princess Street, ManchesterM1 7DN, United Kingdom,Center
for Computing in Engineering & Sciences, University of Campinas, Rua Josué de Castro, s/n, Campinas13083-861, Brazil
| | - Rolly Yadav
- Department
of Chemistry, Indian Institute of Technology
Guwahati, Guwahati, Assam781039, India
| | - Thirakorn Mokkawes
- Manchester
Institute of Biotechnology and Department of Chemical Engineering, The University of Manchester, 131 Princess Street, ManchesterM1 7DN, United Kingdom
| | - Asheesh Kumar
- Department
of Physics, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh (U.P.)226025, India
| | - Munir S. Skaf
- Center
for Computing in Engineering & Sciences, University of Campinas, Rua Josué de Castro, s/n, Campinas13083-861, Brazil
| | - Chivukula V. Sastri
- Department
of Chemistry, Indian Institute of Technology
Guwahati, Guwahati, Assam781039, India,
| | - Devesh Kumar
- Department
of Physics, Siddharth University, Kapilvastu, Siddharthnagar272202, India,
| | - Sam P. de Visser
- Manchester
Institute of Biotechnology and Department of Chemical Engineering, The University of Manchester, 131 Princess Street, ManchesterM1 7DN, United Kingdom,
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12
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Mokkawes T, Lim ZQ, de Visser SP. Mechanism of Melatonin Metabolism by CYP1A1: What Determines the Bifurcation Pathways of Hydroxylation versus Deformylation? J Phys Chem B 2022; 126:9591-9606. [PMID: 36380557 PMCID: PMC9706573 DOI: 10.1021/acs.jpcb.2c07200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Melatonin, a widely applied cosmetic active ingredient, has a variety of uses as a skin protector through antioxidant and anti-inflammatory functions as well as giving the body UV-induced defenses and immune system support. In the body, melatonin is synthesized from a tryptophan amino acid in a cascade of reactions, but as melatonin is toxic at high concentrations, it is metabolized in the human skin by the cytochrome P450 enzymes. The P450s are diverse heme-based mono-oxygenases that catalyze oxygen atom-transfer processes that trigger metabolism and detoxification reactions in the body. In the catalytic cycle of the P450s, a short-lived high-valent iron(IV)-oxo heme cation radical is formed that has been proposed to be the active oxidant. How and why it activates melatonin in the human body and what the origin of the product distributions is, are unknown. This encouraged us to do a detailed computational study on a typical human P450 isozyme, namely CYP1A1. We initially did a series of molecular dynamics simulations with substrate docked into several orientations. These simulations reveal a number of stable substrate-bound positions in the active site, which may lead to differences in substrate activation channels. Using tunneling analysis on the full protein structures, we show that two of the four binding conformations lead to open substrate-binding pockets. As a result, in these open pockets, the substrate is not tightly bound and can escape back into the solution. In the closed conformations, in contrast, the substrate is mainly oriented with the methoxy group pointing toward the heme, although under a different angle. We then created large quantum cluster models of the enzyme and focused on the chemical reaction mechanisms for melatonin activation, leading to competitive O-demethylation and C6-aromatic hydroxylation pathways. The calculations show that active site positioning determines the product distributions, but the bond that is activated is not necessarily closest to the heme in the enzyme-substrate complex. As such, the docking and molecular dynamics positioning of the substrate versus oxidant can give misleading predictions on product distributions. In particular, in quantum mechanics cluster model I, we observe that through a tight hydrogen bonding network, a preferential 6-hydroxylation of melatonin is obtained. However, O-demethylation becomes possible in alternative substrate-binding orientations that have the C6-aromatic ring position shielded. Finally, we investigated enzymatic and non-enzymatic O-demethylation processes and show that the hydrogen bonding network in the substrate-binding pocket can assist and perform this step prior to product release from the enzyme.
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Affiliation(s)
- Thirakorn Mokkawes
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess
Street, Manchester M1 7DN, U.K.,Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, U.K.
| | - Ze Qing Lim
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess
Street, Manchester M1 7DN, U.K.,Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, U.K.
| | - Sam P. de Visser
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess
Street, Manchester M1 7DN, U.K.,Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, U.K.,
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13
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Singh W, Santos SF, James P, Black GW, Huang M, Dubey KD. Single-Site Mutation Induces Water-Mediated Promiscuity in Lignin Breaking Cytochrome P450 GcoA. ACS OMEGA 2022; 7:21109-21118. [PMID: 35755387 PMCID: PMC9219061 DOI: 10.1021/acsomega.2c00524] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/19/2022] [Indexed: 05/10/2023]
Abstract
Cytochrome P450GcoA is an enzyme that catalyzes the guaiacol unit of lignin during the lignin breakdown via an aryl-O-demethylation reaction. This reaction is intriguing and is of commercial importance for its potential applications in the production of biofuel and plastic from biomass feedstock. Recently, the F169A mutation in P450GcoA elicits a promiscuous activity for syringol while maintaining the native activity for guaiacol. Using comprehensive MD simulations and hybrid QM/MM calculations, we address, herein, the origin of promiscuity in P450GcoA and its relevance to the specific activity toward lignin-derived substrates. Our study shows a crucial role of an aromatic dyad of F169 and F395 by regulating the water access to the catalytic center. The F169A mutation opens a water aqueduct and hence increases the native activity for G-lignin. We show that syringol binds very tightly to the WT enzyme, which blocks the conformational rearrangement needed for the second step of O-demethylation. The F169A creates an extra room favoring the conformational rearrangement in the 3-methoxycatechol (3MC) and second dose of the dioxygen insertion. Therefore, using MD simulations and complemented by thorough QM/MM calculations, our study shows how a single-site mutation rearchitects active site engineering for promiscuous syringol activity.
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Affiliation(s)
- Warispreet Singh
- Department
of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1
8ST, United Kingdom
- Hub
for Biotechnology in Build Environment, Newcastle upon Tyne NE1 8ST, United Kingdom
| | - Sónia F.
G. Santos
- Department
of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1
8ST, United Kingdom
- Hub
for Biotechnology in Build Environment, Newcastle upon Tyne NE1 8ST, United Kingdom
| | - Paul James
- Department
of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1
8ST, United Kingdom
- Hub
for Biotechnology in Build Environment, Newcastle upon Tyne NE1 8ST, United Kingdom
| | - Gary W. Black
- Department
of Applied Sciences, Northumbria University, Newcastle upon Tyne NE1
8ST, United Kingdom
- Hub
for Biotechnology in Build Environment, Newcastle upon Tyne NE1 8ST, United Kingdom
| | - Meilan Huang
- Department
of Chemistry & Chemical Engineering, Queen’s University, Belfast BT9 5AG, United Kingdom
| | - Kshatresh Dutta Dubey
- Department
of Chemistry and Centre for Informatics, Shiv Nadar University Delhi NCR, Gautam Buddha Nagar, U.P. 201314, India
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14
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Song X, Zhao S, Xu Y, Chen X, Wang S, Zhao P, Pu Y, Ragauskas AJ. Preparation, Properties, and Application of Lignocellulosic-Based Fluorescent Carbon Dots. CHEMSUSCHEM 2022; 15:e202102486. [PMID: 35199466 DOI: 10.1002/cssc.202102486] [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: 11/23/2021] [Revised: 01/29/2022] [Indexed: 06/14/2023]
Abstract
Carbon dots (CDs) are a relatively new type of fluorescent carbon material with excellent performance and widespread application. As the most readily available and widely distributed biomass resource, lignocellulosics are a renewable bioresource with great potential. Research into the preparation of CDs with lignocellulose (LC-CDs) has become the focus of numerous researchers. Compared with other carbon sources, lignocellulose is low cost, rich in structural variety, exhibits excellent biocompatibility,[1] and the structures of CDs prepared by lignin, cellulose, and hemicellulose are similar. This Review summarized research progress in the preparation of CDs from lignocellulosics in recent years and reviewed traditional and new preparation methods, physical and chemical properties, optical properties, and applications of LC-CDs, providing guidance for the formation and improvement of LC-CDs. In addition, the challenges of synthesizing LC-CDs were also highlighted, including the interaction of different lignocellulose components on the formation of LC-CDs and the nucleation and growth mechanism of LC-CDs; from this, current trends and opportunities of LC-CDs were examined, and some research methods for future research were put forward.
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Affiliation(s)
- Xueping Song
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, P. R. China
- Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning, 530004, P. R. China
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, USA
| | - Siyu Zhao
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, P. R. China
- Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning, 530004, P. R. China
| | - Ying Xu
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, P. R. China
- Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning, 530004, P. R. China
| | - Xinrui Chen
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, P. R. China
- Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning, 530004, P. R. China
| | - Shuangfei Wang
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, P. R. China
- Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning, 530004, P. R. China
| | - Peitao Zhao
- School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou, 221116, P. R. China
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, USA
| | - Yunqiao Pu
- Joint Institute for Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Arthur J Ragauskas
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, USA
- Joint Institute for Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Center for Renewable Carbon, Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN, 37996, USA
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15
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Zhang H, Song R, Guo F, Chai L, Wang W, Zeng J, Yu H, Ji L. Using Physical Organic Chemistry Knowledge to Predict Unusual Metabolites of Synthetic Phenolic Antioxidants by Cytochrome P450. Chem Res Toxicol 2022; 35:840-848. [PMID: 35416036 DOI: 10.1021/acs.chemrestox.2c00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biotransformation, especially by human CYP450 enzymes, plays a crucial role in regulating the toxicity of organic compounds in organisms, but is poorly understood for most emerging pollutants, as their numerous "unusual" biotransformation reactions cannot retrieve examples from the textbooks. Therefore, in order to predict the unknown metabolites with altering toxicological profiles, there is a realistic need to develop efficient methods to reveal the "unusual" metabolic mechanism of emerging pollutants. Combining experimental work with computational predictions has been widely accepted as an effective approach in studying complex metabolic reactions; however, the full quantum chemical computations may not be easily accessible for most environmentalists. Alternatively, this work practiced using the concepts from physical organic chemistry for studying the interrelationships between structure and reactivity of organic molecules, to reveal the "unusual" metabolic mechanism of synthetic phenolic antioxidants catalyzed by CYP450, for which the simple pencil-and-paper and property-computation methods based on physical organic chemistry were performed. The phenol-coupling product of butylated hydroxyanisole (BHA) (based on spin aromatic delocalization) and ipso-addition quinol metabolite of butylated hydroxytoluene (BHT) (based on hyperconjugative effect) were predicted as two "unusual" metabolites, which were further confirmed by our in vitro analysis. We hope this easily handled approach will promote environmentalists to attach importance to physical organic chemistry, with an eye to being able to use the knowledge gained to efficiently predict the fates of substantial unknown synthesized organic compounds in the future.
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Affiliation(s)
- Huanni Zhang
- 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
| | - Runqian Song
- 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
| | - Fangjie Guo
- School of Management Engineering and Electronic Commerce, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Lihong Chai
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 81377 Munich, Germany
| | - Wuwei Wang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Jingyi Zeng
- 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
| | - Li Ji
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
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16
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Liu X, Yuan Z, Su H, Hou X, Deng Z, Xu H, Guo B, Yin D, Sheng X, Rao Y. Molecular Basis of the Unusual Seven-Membered Methylenedioxy Bridge Formation Catalyzed by Fe(II)/α-KG-Dependent Oxygenase CTB9. ACS Catal 2022. [DOI: 10.1021/acscatal.1c04627] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Xuanzhong Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, P. R. China
| | - Zhenbo Yuan
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, P. R. China
| | - Hao Su
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences and National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, P. R. China
| | - Xiaodong Hou
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, P. R. China
| | - Zhiwei Deng
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, P. R. China
| | - Huibin Xu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, P. R. China
| | - Baodang Guo
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, P. R. China
| | - Dejing Yin
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, P. R. China
| | - Xiang Sheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences and National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, P. R. China
| | - Yijian Rao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, P. R. China
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17
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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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18
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Zhang S, Li X, Wang Y, Wei J, Zhang X, Liu Y. Computational Study of the Peroxygenase Mechanism Catalyzed by Hemoglobin Dehaloperoxidase Involved in the Degradation of Chlorophenols. Inorg Chem 2022; 61:2628-2639. [PMID: 35080380 DOI: 10.1021/acs.inorgchem.1c03721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The biochemical evidence showed that hemoglobin dehaloperoxidase (DHP B) from Amphitrite Ornata is a multifunctional hemoprotein that catalyzes both dehalogenation and hydroxylation of halophenols via the peroxidase and peroxygenase mechanism, respectively, which sets the basis for the degradation of halophenols. In the peroxygenase mechanism, the reaction was previously suggested to be triggered either by the hydrogen atom abstraction by the Fe═O center or by the proton abstraction by His55. To illuminate the peroxygenase mechanism of DHP B at the atomistic level, on the basis of the high-resolution crystal structure, computational models were constructed, and a series of quantum mechanical/molecular mechanical calculations have been performed. According to the calculation results, the pathway (Path a) initiated by the H-abstraction by the Fe═O center is feasible. In another pathway (Path b), His55 can abstract the proton from the hydroxyl group of the substrate (4-Cl-o-cresol) to initiate the reaction; however, its feasibility depends on the prior electron transfer from the substrate to the porphyrin group. The rate-limiting step of Path a is the OH-rebound, which corresponds to an energy barrier of 14.7 kcal/mol at the quartet state. His55 acts as an acid-base catalyst and directly involves in the catalysis. Our mutant study indicates that His55 can be replaced by other titratable residues. These findings may provide useful information for further understanding of the catalytic reaction of DHP B and for the design of enzymes in the degradation of pollutants, in particular, halophenols.
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Affiliation(s)
- Shiqing Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Xinyi Li
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yijing Wang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Jingjing Wei
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Xue Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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19
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de Visser SP, Mukherjee G, Ali HS, Sastri CV. Local Charge Distributions, Electric Dipole Moments, and Local Electric Fields Influence Reactivity Patterns and Guide Regioselectivities in α-Ketoglutarate-Dependent Non-heme Iron Dioxygenases. Acc Chem Res 2022; 55:65-74. [PMID: 34915695 DOI: 10.1021/acs.accounts.1c00538] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Non-heme iron dioxygenases catalyze vital processes for human health related to the biosynthesis of essential products and the biodegradation of toxic metabolites. Often the natural product biosyntheses by these non-heme iron dioxygenases is highly regio- and chemoselective, which are commonly assigned to tight substrate-binding and positioning. However, recent high-level computational modeling has shown that substrate-binding and positioning is only part of the story and long-range electrostatic interactions can play a major additional role.In this Account, we review and summarize computational viewpoints on the high regio- and chemoselectivity of α-ketoglutarate-dependent non-heme iron dioxygenases and how external perturbations affect the catalysis. In particular, studies from our groups have shown that often a regioselectivity in enzymes can be accomplished by stabilization of the rate-determining transition state for the reaction through external charges, electric dipole moments, or local electric field effects. Furthermore, bond dissociation energies in molecules are shown to be influenced by an electric field effect, and through targeting a specific bond in an electric field, this can lead to an unusually specific reaction. For instance, in the carbon-induced starvation protein, we studied two substrate-bound conformations and showed that regardless of what C-H bond of the substrate is closest to the iron(IV)-oxo oxidant, the lowest hydrogen atom abstraction barrier is always for the pro-S C2-H abstraction due to an induced dipole moment of the protein that weakens this bond. In another example of the hygromycin biosynthesis enzyme, an oxidative ring-closure reaction in the substrate forms an ortho-δ-ester ring. Calculations on this enzyme show that the selectivity is guided by a protonated lysine residue in the active site that, through its positive charge, triggers a low energy hydrogen atom abstraction barrier. A final set of examples in this Account discuss the viomycin biosynthesis enzyme and the 2-(trimethylammonio)ethylphosphonate dioxygenase (TmpA) enzyme. Both of these enzymes are shown to possess a significant local dipole moment and local electric field effect due to charged residues surrounding the substrate and oxidant binding pockets. The protein dipole moment and local electric field strength changes the C-H bond strengths of the substrate as compared to the gas-phase triggers the regioselectivity of substrate activation. In particular, we show that in the gas phase and in a protein environment C-H bond strengths are different due to local electric dipole moments and electric field strengths. These examples show that enzymes have an intricately designed structure that enables a chemical reaction under ambient conditions through the positioning of positively and negatively charged residues that influence and enhance reaction mechanisms. These computational insights create huge possibilities in bioengineering to apply local electric field and dipole moments in proteins to achieve an unusual selectivity and specificity and trigger a fit-for-purpose biocatalyst for unique biotransformations.
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Affiliation(s)
- Sam P. de Visser
- Manchester Institute of Biotechnology and Department of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department of Chemistry, Indian Institute of Technology Guwahati, 781039 Assam, India
| | - Gourab Mukherjee
- Department of Chemistry, Indian Institute of Technology Guwahati, 781039 Assam, India
| | - Hafiz Saqib Ali
- Manchester Institute of Biotechnology and Department of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Chivukula V. Sastri
- Department of Chemistry, Indian Institute of Technology Guwahati, 781039 Assam, India
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20
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Wong HPH, Mokkawes T, de Visser SP. Can the isonitrile biosynthesis enzyme ScoE assist with the biosynthesis of isonitrile groups in drug molecules? A computational study. Phys Chem Chem Phys 2022; 24:27250-27262. [DOI: 10.1039/d2cp03409c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Computational studies show that the isonitrile synthesizing enzyme ScoE can catalyse the conversion of γ-Gly substituents in substrates to isonitrile. This enables efficient isonitrile substitution into target molecules such as axisonitrile-1.
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Affiliation(s)
- Henrik P. H. Wong
- Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK
- Department of Chemical Engineering, Oxford Road, Manchester M13 9PL, UK
| | - Thirakorn Mokkawes
- Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK
- Department of Chemical Engineering, Oxford Road, Manchester M13 9PL, UK
| | - Sam P. de Visser
- Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK
- Department of Chemical Engineering, Oxford Road, Manchester M13 9PL, UK
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21
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Chen H, Zhou A, Sun D, Zhao Y, Wang Y. Theoretical Investigation on the Elusive Reaction Mechanism of Spirooxindole Formation Mediated by Cytochrome P450s: A Nascent Feasible Charge-Shift C-O Bond Makes a Difference. J Phys Chem B 2021; 125:8419-8430. [PMID: 34313131 DOI: 10.1021/acs.jpcb.1c04088] [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
Spirooxindoles are pivotal biofunctional groups widely distributed in natural products and clinic drugs. However, construction of such subtle chiral skeletons is a long-standing challenge to both organic and bioengineering scientists. The knowledge of enzymatic spirooxindole formation in nature may inspire rational design of new catalysts. To this end, we presented a theoretical investigation on the elusive mechanism of the spiro-ring formation at the 3-position of oxindole mediated by cytochrome P450 enzymes (P450). Our calculated results demonstrated that the electrophilic attack of CpdI, the active species of P450, to the substrate, shows regioselectivity, i.e., the attack at the C9 position forms a tetrahedral intermediate involving an unusual feasible charge-shift C9δ+-Oδ- bond, while the attack at the C1 position forms an epoxide intermediate. The predominant route is the first route with the charge-shift bonding intermediate due to holding a relatively lower barrier by >5 kcal mol-1 than the epoxide route, which fits the experimental observations. Such a delocalized charge-shift bond facilitates the formation of a spiro-ring mainly through elongation of the C1-C9 bond to eliminate the aromatization of the tricyclic beta-carboline. Our theoretical results shed profound mechanistic insights for the first time into the elusive spirooxindole formation mediated by P450s.
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Affiliation(s)
- Huanhuan Chen
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.,Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, Zhejiang, China
| | - Anran Zhou
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.,Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, Zhejiang, China
| | - Dongru Sun
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.,Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, Zhejiang, China
| | - Yufen Zhao
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.,Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, Zhejiang, China
| | - Yong Wang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, Zhejiang, China.,Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, Zhejiang, China
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22
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Product Distributions of Cytochrome P450 OleT JE with Phenyl-Substituted Fatty Acids: A Computational Study. Int J Mol Sci 2021; 22:ijms22137172. [PMID: 34281222 PMCID: PMC8269385 DOI: 10.3390/ijms22137172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 11/17/2022] Open
Abstract
There are two types of cytochrome P450 enzymes in nature, namely, the monooxygenases and the peroxygenases. Both enzyme classes participate in substrate biodegradation or biosynthesis reactions in nature, but the P450 monooxygenases use dioxygen, while the peroxygenases take H2O2 in their catalytic cycle instead. By contrast to the P450 monooxygenases, the P450 peroxygenases do not require an external redox partner to deliver electrons during the catalytic cycle, and also no external proton source is needed. Therefore, they are fully self-sufficient, which affords them opportunities in biotechnological applications. One specific P450 peroxygenase, namely, P450 OleTJE, reacts with long-chain linear fatty acids through oxidative decarboxylation to form hydrocarbons and, as such, has been implicated as a suitable source for the biosynthesis of biofuels. Unfortunately, the reactions were shown to produce a considerable amount of side products originating from Cα and Cβ hydroxylation and desaturation. These product distributions were found to be strongly dependent on whether the substrate had substituents on the Cα and/or Cβ atoms. To understand the bifurcation pathways of substrate activation by P450 OleTJE leading to decarboxylation, Cα hydroxylation, Cβ hydroxylation and Cα–Cβ desaturation, we performed a computational study using 3-phenylpropionate and 2-phenylbutyrate as substrates. We set up large cluster models containing the heme, the substrate and the key features of the substrate binding pocket and calculated (using density functional theory) the pathways leading to the four possible products. This work predicts that the two substrates will react with different reaction rates due to accessibility differences of the substrates to the active oxidant, and, as a consequence, these two substrates will also generate different products. This work explains how the substrate binding pocket of P450 OleTJE guides a reaction to a chemoselectivity.
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23
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Negative catalysis / non-Bell-Evans-Polanyi reactivity by metalloenzymes: Examples from mononuclear heme and non-heme iron oxygenases. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213914] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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24
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Roach S, Faponle AS, Satpathy JK, Sastri CV, de Visser SP. Substrate sulfoxidation by a biomimetic cytochrome P450 Compound I mimic: How do porphyrin and phthalocyanine equatorial ligands compare? J CHEM SCI 2021. [DOI: 10.1007/s12039-021-01917-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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25
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Density Functional Theory Study into the Reaction Mechanism of Isonitrile Biosynthesis by the Nonheme Iron Enzyme ScoE. Top Catal 2021. [DOI: 10.1007/s11244-021-01460-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AbstractThe nonheme iron enzyme ScoE catalyzes the biosynthesis of an isonitrile substituent in a peptide chain. To understand details of the reaction mechanism we created a large active site cluster model of 212 atoms that contains substrate, the active oxidant and the first- and second-coordination sphere of the protein and solvent. Several possible reaction mechanisms were tested and it is shown that isonitrile can only be formed through two consecutive catalytic cycles that both use one molecule of dioxygen and α-ketoglutarate. In both cycles the active species is an iron(IV)-oxo species that in the first reaction cycle reacts through two consecutive hydrogen atom abstraction steps: first from the N–H group and thereafter from the C–H group to desaturate the NH-CH2 bond. The alternative ordering of hydrogen atom abstraction steps was also tested but found to be higher in energy. Moreover, the electronic configurations along that pathway implicate an initial hydride transfer followed by proton transfer. We highlight an active site Lys residue that is shown to donate charge in the transition states and influences the relative barrier heights and bifurcation pathways. A second catalytic cycle of the reaction of iron(IV)-oxo with desaturated substrate starts with hydrogen atom abstraction followed by decarboxylation to give isonitrile directly. The catalytic cycle is completed with a proton transfer to iron(II)-hydroxo to generate the iron(II)-water resting state. The work is compared with experimental observation and previous computational studies on this system and put in a larger perspective of nonheme iron chemistry.
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26
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Enzymatic N N bond formation: Mechanism for the N-nitroso synthesis catalyzed by non-heme iron SznF enzyme. J Catal 2021. [DOI: 10.1016/j.jcat.2021.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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27
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Ali HS, Henchman RH, Visser SP. Mechanism of Oxidative Ring‐Closure as Part of the Hygromycin Biosynthesis Step by a Nonheme Iron Dioxygenase. ChemCatChem 2021. [DOI: 10.1002/cctc.202100393] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Hafiz Saqib Ali
- Manchester Institute of Biotechnology The University of Manchester 131 Princess Street Manchester M1 7DN UK
- Department of Chemistry The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Richard H. Henchman
- Manchester Institute of Biotechnology The University of Manchester 131 Princess Street Manchester M1 7DN UK
- Department of Chemistry The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Sam P. Visser
- Manchester Institute of Biotechnology The University of Manchester 131 Princess Street Manchester M1 7DN UK
- Department of Chemical Engineering and Analytical Science The University of Manchester Oxford Road Manchester M13 9PL UK
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28
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Cheng Q, DeYonker NJ. QM-Cluster Model Study of the Guaiacol Hydrogen Atom Transfer and Oxygen Rebound with Cytochrome P450 Enzyme GcoA. J Phys Chem B 2021; 125:3296-3306. [PMID: 33784103 DOI: 10.1021/acs.jpcb.0c10761] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The key step of the O-demethylation of guaiacol by GcoA of the cytochrome P450-reductase pair was studied with DFT using two 10-residue and three 15-residue QM-cluster models. For each model, two reaction pathways were examined, beginning with a different guaiacol orientation. Based on this study, His354, Phe349, Glu249, and Pro250 residues were found to be important for keeping the heme in a planar geometry throughout the reaction. Val241 and Gly245 residues were needed in the QM-cluster models to provide the hydrophobic pocket for an appropriate guaiacol pose in the reaction. The aromatic triad Phe75, Phe169, and Phe395 may be necessary to facilitate guaiacol migrating into the enzyme active site, but it does not qualitatively affect kinetics and thermodynamics of the proposed mechanism. All QM-cluster models created by RINRUS agree very well with previous experimental work. This study provides details for better understanding enzymatic O-demethylation of lignins to form catechol derivatives by GcoA.
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Affiliation(s)
- Qianyi Cheng
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, United States
| | - Nathan J DeYonker
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, United States
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29
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Ellis E, Hinchen DJ, Bleem A, Bu L, Mallinson SJB, Allen MD, Streit BR, Machovina MM, Doolin QV, Michener WE, Johnson CW, Knott BC, Beckham GT, McGeehan JE, DuBois JL. Engineering a Cytochrome P450 for Demethylation of Lignin-Derived Aromatic Aldehydes. JACS AU 2021; 1:252-261. [PMID: 34467290 PMCID: PMC8395679 DOI: 10.1021/jacsau.0c00103] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Indexed: 05/12/2023]
Abstract
Biological funneling of lignin-derived aromatic compounds is a promising approach for valorizing its catalytic depolymerization products. Industrial processes for aromatic bioconversion will require efficient enzymes for key reactions, including demethylation of O-methoxy-aryl groups, an essential and often rate-limiting step. The recently characterized GcoAB cytochrome P450 system comprises a coupled monoxygenase (GcoA) and reductase (GcoB) that catalyzes oxidative demethylation of the O-methoxy-aryl group in guaiacol. Here, we evaluate a series of engineered GcoA variants for their ability to demethylate o-and p-vanillin, which are abundant lignin depolymerization products. Two rationally designed, single amino acid substitutions, F169S and T296S, are required to convert GcoA into an efficient catalyst toward the o- and p-isomers of vanillin, respectively. Gain-of-function in each case is explained in light of an extensive series of enzyme-ligand structures, kinetic data, and molecular dynamics simulations. Using strains of Pseudomonas putida KT2440 already optimized for p-vanillin production from ferulate, we demonstrate demethylation by the T296S variant in vivo. This work expands the known aromatic O-demethylation capacity of cytochrome P450 enzymes toward important lignin-derived aromatic monomers.
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Affiliation(s)
- Emerald
S. Ellis
- Department
of Chemistry and Biochemistry, Montana State
University, 103 Chemistry and Biochemistry Building, PO Box 173400, Bozeman, Montana 59717, United States
| | - Daniel J. Hinchen
- Centre
for Enzyme Innovation, School of Biological Sciences, Institute of
Biological and Biomedical Sciences, University
of Portsmouth, Portsmouth PO1 2DY, United Kingdom
| | - Alissa Bleem
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
- Center
for Bioenergy Innovation, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Lintao Bu
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Sam J. B. Mallinson
- Centre
for Enzyme Innovation, School of Biological Sciences, Institute of
Biological and Biomedical Sciences, University
of Portsmouth, Portsmouth PO1 2DY, United Kingdom
| | - Mark D. Allen
- Centre
for Enzyme Innovation, School of Biological Sciences, Institute of
Biological and Biomedical Sciences, University
of Portsmouth, Portsmouth PO1 2DY, United Kingdom
| | - Bennett R. Streit
- Department
of Chemistry and Biochemistry, Montana State
University, 103 Chemistry and Biochemistry Building, PO Box 173400, Bozeman, Montana 59717, United States
| | - Melodie M. Machovina
- Department
of Chemistry and Biochemistry, Montana State
University, 103 Chemistry and Biochemistry Building, PO Box 173400, Bozeman, Montana 59717, United States
| | - Quinlan V. Doolin
- Department
of Chemistry and Biochemistry, Montana State
University, 103 Chemistry and Biochemistry Building, PO Box 173400, Bozeman, Montana 59717, United States
| | - William E. Michener
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Christopher W. Johnson
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Brandon C. Knott
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Gregg T. Beckham
- Renewable
Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
- Center
for Bioenergy Innovation, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37830, United States
| | - John E. McGeehan
- Centre
for Enzyme Innovation, School of Biological Sciences, Institute of
Biological and Biomedical Sciences, University
of Portsmouth, Portsmouth PO1 2DY, United Kingdom
| | - Jennifer L. DuBois
- Department
of Chemistry and Biochemistry, Montana State
University, 103 Chemistry and Biochemistry Building, PO Box 173400, Bozeman, Montana 59717, United States
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30
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Ali HS, Henchman RH, Warwicker J, de Visser SP. How Do Electrostatic Perturbations of the Protein Affect the Bifurcation Pathways of Substrate Hydroxylation versus Desaturation in the Nonheme Iron-Dependent Viomycin Biosynthesis Enzyme? J Phys Chem A 2021; 125:1720-1737. [DOI: 10.1021/acs.jpca.1c00141] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Hafiz Saqib Ali
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Richard H. Henchman
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jim Warwicker
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Sam P. de Visser
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
- Department of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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31
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Ali HS, Henchman RH, de Visser SP. Lignin Biodegradation by a Cytochrome P450 Enzyme: A Computational Study into Syringol Activation by GcoA. Chemistry 2020; 26:13093-13102. [PMID: 32613677 PMCID: PMC7590115 DOI: 10.1002/chem.202002203] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Indexed: 12/12/2022]
Abstract
A recently characterized cytochrome P450 isozyme GcoA activates lignin components through a selective O-demethylation or alternatively an acetal formation reaction. These are important reactions in biotechnology and, because lignin is readily available; it being the main component in plant cell walls. In this work we present a density functional theory study on a large active site model of GcoA to investigate syringol activation by an iron(IV)-oxo heme cation radical oxidant (Compound I) leading to hemiacetal and acetal products. Several substrate-binding positions were tested and full energy landscapes calculated. The study shows that substrate positioning determines the product distributions. Thus, with the phenol group pointing away from the heme, an O-demethylation is predicted, whereas an initial hydrogen-atom abstraction of the weak phenolic O-H group would trigger a pathway leading to ring-closure to form acetal products. Predictions on how to engineer P450 GcoA to get more selective product distributions are given.
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Affiliation(s)
- Hafiz Saqib Ali
- Manchester Institute of BiotechnologyThe University of Manchester131 Princess StreetManchesterM1 7DNUnited Kingdom
- Department of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
| | - Richard H. Henchman
- Manchester Institute of BiotechnologyThe University of Manchester131 Princess StreetManchesterM1 7DNUnited Kingdom
- Department of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
| | - Sam P. de Visser
- Manchester Institute of BiotechnologyThe University of Manchester131 Princess StreetManchesterM1 7DNUnited Kingdom
- Department of Chemical Engineering and Analytical ScienceThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
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