1
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Ju S, Li D, Mai BK, Liu X, Vallota-Eastman A, Wu J, Valentine DL, Liu P, Yang Y. Stereodivergent photobiocatalytic radical cyclization through the repurposing and directed evolution of fatty acid photodecarboxylases. Nat Chem 2024; 16:1339-1347. [PMID: 38632367 PMCID: PMC11321912 DOI: 10.1038/s41557-024-01494-0] [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: 07/27/2023] [Accepted: 02/28/2024] [Indexed: 04/19/2024]
Abstract
Despite their intriguing photophysical and photochemical activities, naturally occurring photoenzymes have not yet been repurposed for new-to-nature activities. Here we engineered fatty acid photodecarboxylases to catalyse unnatural photoredox radical C-C bond formation by leveraging the strongly oxidizing excited-state flavoquinone cofactor. Through genome mining, rational engineering and directed evolution, we developed a panel of radical photocyclases to facilitate decarboxylative radical cyclization with excellent chemo-, enantio- and diastereoselectivities. Our high-throughput experimental workflow allowed for the directed evolution of fatty acid photodecarboxylases. An orthogonal set of radical photocyclases was engineered to access all four possible stereoisomers of the stereochemical dyad, affording fully diastereo- and enantiodivergent biotransformations in asymmetric radical biocatalysis. Molecular dynamics simulations show that our evolved radical photocyclases allow near-attack conformations to be easily accessed, enabling chemoselective radical cyclization. The development of stereoselective radical photocyclases provides unnatural C-C-bond-forming activities in natural photoenzyme families, which can be used to tame the stereochemistry of free-radical-mediated reactions.
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Affiliation(s)
- Shuyun Ju
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Dian Li
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xin Liu
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Alec Vallota-Eastman
- Interdepartmental Graduate Program for Marine Science, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Jianping Wu
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - David L Valentine
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA, USA
- Department of Earth Science, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Yang Yang
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA.
- Biomolecular Science and Engineering (BMSE) Program, University of California Santa Barbara, Santa Barbara, CA, USA.
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2
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Vedalankar P, Tripathy BC. Light dependent protochlorophyllide oxidoreductase: a succinct look. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2024; 30:719-731. [PMID: 38846463 PMCID: PMC11150229 DOI: 10.1007/s12298-024-01454-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 03/01/2024] [Accepted: 04/29/2024] [Indexed: 06/09/2024]
Abstract
Reducing protochlorophyllide (Pchlide) to chlorophyllide (Chlide) is a major regulatory step in the chlorophyll biosynthesis pathway. This reaction is catalyzed by light-dependent protochlorophyllide oxidoreductase (LPOR) in oxygenic phototrophs, particularly angiosperms. LPOR-NADPH and Pchlide form a ternary complex to be efficiently photo-transformed to synthesize Chlide and, subsequently, chlorophyll during the transition from skotomorphogenesis to photomorphogenesis. Besides lipids, carotenoids and poly-cis xanthophylls influence the formation of the photoactive LPOR complexes and the PLBs. The crystal structure of LPOR reveals evolutionarily conserved cysteine residues implicated in the Pchlide binding and catalysis around the active site. Different isoforms of LPOR viz PORA, PORB, and PORC expressed at different stages of chloroplast development play a photoprotective role by quickly transforming the photosensitive Pchlide to Chlide. Non-photo-transformed Pchlide acts as a photosensitizer to generate singlet oxygen that causes oxidative stress and cell death. Therefore, different isoforms of LPOR have evolved and differentially expressed during plant development to protect plants from photodamage and thus play a pivotal role during photomorphogenesis. This review brings out the salient features of LPOR structure, structure-function relationships, and ultra-fast photo transformation of Pchlide to Chlide by oligomeric and polymeric forms of LPOR.
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Affiliation(s)
| | - Baishnab C. Tripathy
- Department of Biotechnology, Sharda University, Greater Noida, Uttar Pradesh 201310 India
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3
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Grotjahn S, Graf C, Zelenka J, Pattanaik A, Müller L, Kutta RJ, Rehbein J, Roithová J, Gschwind RM, Nuernberger P, König B. Reactivity of Superbasic Carbanions Generated via Reductive Radical-Polar Crossover in the Context of Photoredox Catalysis. Angew Chem Int Ed Engl 2024; 63:e202400815. [PMID: 38408163 DOI: 10.1002/anie.202400815] [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: 01/12/2024] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 02/28/2024]
Abstract
Photocatalytic reactions involving a reductive radical-polar crossover (RRPCO) generate intermediates with carbanionic reactivity. Many of these proposed intermediates resemble highly reactive organometallic compounds. However, conditions of their formation are generally not tolerated by their isolated organometallic versions and often a different reactivity is observed. Our investigations on their nature and reactivity under commonly used photocatalytic conditions demonstrate that these intermediates are indeed best described as free, superbasic carbanions capable of deprotonating common polar solvents usually assumed to be inert such as acetonitrile, dimethylformamide, and dimethylsulfoxide. Their basicity not only towards solvents but also towards electrophiles, such as aldehydes, ketones, and esters, is comparable to the reactivity of isolated carbanions in the gas-phase. Previously unsuccessful transformations thought to result from a lack of reactivity are explained by their high reactivity towards the solvent and weakly acidic protons of reaction partners. An intuitive explanation for the mode of action of photocatalytically generated carbanions is provided, which enables methods to verify reaction mechanisms proposed to involve an RRPCO step and to identify the reasons for the limitations of current methods.
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Affiliation(s)
- Sascha Grotjahn
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Christina Graf
- Faculty of Chemistry and Pharmacy, Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Jan Zelenka
- Department of Spectroscopy and Catalysis, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ, Nijmegen, the Netherlands
| | - Aryaman Pattanaik
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Lea Müller
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Roger Jan Kutta
- Faculty of Chemistry and Pharmacy, Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Julia Rehbein
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Jana Roithová
- Department of Spectroscopy and Catalysis, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ, Nijmegen, the Netherlands
| | - Ruth M Gschwind
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Patrick Nuernberger
- Faculty of Chemistry and Pharmacy, Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Burkhard König
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
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4
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Taylor A, Zhang S, Johannissen LO, Sakuma M, Phillips RS, Green AP, Hay S, Heyes DJ, Scrutton NS. Mechanistic implications of the ternary complex structural models for the photoenzyme protochlorophyllide oxidoreductase. FEBS J 2024; 291:1404-1421. [PMID: 38060334 DOI: 10.1111/febs.17025] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/13/2023] [Accepted: 12/05/2023] [Indexed: 04/04/2024]
Abstract
The photoenzyme protochlorophyllide oxidoreductase (POR) is an important enzyme for understanding biological H-transfer mechanisms. It uses light to catalyse the reduction of protochlorophyllide to chlorophyllide, a key step in chlorophyll biosynthesis. Although a wealth of spectroscopic data have provided crucial mechanistic insight, a structural rationale for POR photocatalysis has proved challenging and remains hotly debated. Recent structural models of the ternary enzyme-substrate complex, derived from crystal and electron microscopy data, show differences in the orientation of the protochlorophyllide substrate and the architecture of the POR active site, with significant implications for the catalytic mechanism. Here, we use a combination of computational and experimental approaches to investigate the compatibility of each structural model with the hypothesised reaction mechanisms and propose an alternative structural model for the cyanobacterial POR ternary complex. We show that a strictly conserved tyrosine, previously proposed to act as the proton donor in POR photocatalysis, is unlikely to be involved in this step of the reaction but is crucial for Pchlide binding. Instead, an active site cysteine is important for both hydride and proton transfer reactions in POR and is proposed to act as the proton donor, either directly or through a water-mediated network. Moreover, a conserved glutamine is important for Pchlide binding and ensuring efficient photochemistry by tuning its electronic properties, likely by interacting with the central Mg atom of the substrate. This optimal 'binding pose' for the POR ternary enzyme-substrate complex illustrates how light energy can be harnessed to facilitate enzyme catalysis by this unique enzyme.
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Affiliation(s)
- Aoife Taylor
- Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, UK
| | - Shaowei Zhang
- Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, UK
| | - Linus O Johannissen
- Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, UK
| | - Michiyo Sakuma
- Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, UK
| | - Robert S Phillips
- Departments of Chemistry and Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Anthony P Green
- Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, UK
| | - Sam Hay
- Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, UK
| | - Derren J Heyes
- Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, UK
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, UK
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5
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Archipowa N, Wittmann L, Köckenberger J, Ertl FJ, Gleixner J, Keller M, Heinrich MR, Kutta RJ. Characterization of Fluorescent Dyes Frequently Used for Bioimaging: Photophysics and Photocatalytical Reactions with Proteins. J Phys Chem B 2023; 127:9532-9542. [PMID: 37903729 DOI: 10.1021/acs.jpcb.3c04484] [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: 11/01/2023]
Abstract
Derivatives of the rhodamine-based dye 5-TAMRA (5-carboxy-tetramethylrhodamine) and the indocarbocyanine-type Cy3B (cyclized derivative of the cyanine dye Cy3), both representing important fluorophores frequently used for the labeling of biomolecules (proteins, nucleic acids) and bioactive compounds, such as receptor ligands, were photophysically investigated in aqueous solution, i.e., in neat phosphate-buffered saline (PBS) and in PBS supplemented with 1 wt % bovine serum albumin (BSA). The dyes exhibit comparable absorption (λabs,max: 550-569 nm) and emission wavelengths (λem,max: 580-582 nm), and similar S1 lifetimes (2.27-2.75 ns), and their excited state deactivation proceeds mainly via the lowest excited singlet state (triplet quantum yield ca. 1%). However, the probes show marked differences with respect to their fluorescence quantum yield and photostability. While 5-TAMRA shows a lower quantum yield (37-39%) than the Cy3B derivative (ca. 57%), its photostability is considerably higher compared to Cy3B. Generally, the impact of the protein on the photophysics is low. However, on prolonged illumination, both fluorescent dyes undergo a photocatalytic reaction with tryptophan residues of BSA mediated by sensitized singlet oxygen resulting in a tryptophan photoproduct with an absorption maximum around 330 nm. The overall results of this work will assist in choosing the right dye for the labeling of bioactive compounds, and the study demonstrates that experiments performed with 5-TAMRA or Cy3B-labeled compounds in a biological environment may be influenced by photochemical modification of experimentally relevant proteins at aromatic amino acid residues.
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Affiliation(s)
- Nataliya Archipowa
- Institute of Biophysics and Physical Biochemistry, Faculty of Biology and Preclinical Medicine, University of Regensburg, D-93053 Regensburg, Germany
| | - Lukas Wittmann
- Institute of Physical and Theoretical Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Johannes Köckenberger
- Department of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Fabian J Ertl
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Jakob Gleixner
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Markus R Heinrich
- Department of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Roger Jan Kutta
- Institute of Physical and Theoretical Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
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6
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Liu R, Wang L, Meng Y, Tian Y, Li F, Lu H. Theoretical and Experimental Studies on Plant Light-Dependent Protochlorophyllide Oxidoreductase as a Novel Target for Searching Potential Herbicides. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37467369 DOI: 10.1021/acs.jafc.3c01783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
Herbicide resistance is a prevalent problem that has posed a foremost challenge to crop production worldwide. Light-dependent enzyme NADPH: protochlorophyllide oxidoreductase (LPOR) in plants is a metabolic target that could satisfy this unmet demand. Herein, for the first time, we embarked on proposing a new mode of action of herbicides by performing structure-based virtual screening targeting multiple LPOR binding sites, with the determination of further bioactivity on the lead series. The feasibility of exploiting high selectivity and safety herbicides targeting LPOR was discussed from the perspective of the origin and phylogeny. Besides, we revealed the structural rearrangement and the selection key for NADPH cofactor binding to LPOR. Based on these, multitarget virtual screening was performed and the result identified compounds 2 affording micromolar inhibition, in which the IC50 reached 4.74 μM. Transcriptome analysis revealed that compound 2 induced more genes related to chlorophyll synthesis in Arabidopsis thaliana, especially the LPOR genes. Additionally, we clarified that these compounds binding to the site enhanced the overall stability and local rigidity of the complex systems from molecular dynamics simulation. This study delivers a guideline on how to assess activity-determining features of inhibitors to LPOR and how to translate this knowledge into the design of novel and effective inhibitors against malignant weed that act by targeting LPOR.
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Affiliation(s)
- Ruiyuan Liu
- College of Science, China Agricultural University, Beijing 100193, China
| | - Leng Wang
- College of Science, China Agricultural University, Beijing 100193, China
| | - Yue Meng
- College of Science, China Agricultural University, Beijing 100193, China
| | - Yiyi Tian
- College of Science, China Agricultural University, Beijing 100193, China
| | - Fang Li
- College of Science, China Agricultural University, Beijing 100193, China
| | - Huizhe Lu
- College of Science, China Agricultural University, Beijing 100193, China
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7
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Tong L, Lin Y, Kou X, Shen Y, Shen Y, Huang S, Zhu F, Chen G, Ouyang G. Pore-Environment-Dependent Photoresponsive Oxidase-Like Activity in Hydrogen-Bonded Organic Frameworks. Angew Chem Int Ed Engl 2023; 62:e202218661. [PMID: 36719177 DOI: 10.1002/anie.202218661] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/28/2023] [Accepted: 01/31/2023] [Indexed: 02/01/2023]
Abstract
Mimicking the bioactivity of native enzymes through synthetic chemistry is an efficient means to advance the biocatalysts in a cell-free environment, however, remains long-standing challenges. Herein, we utilize structurally explicit hydrogen-bonded organic frameworks (HOFs) to mimic photo-responsive oxidase, and uncover the important role of pore environments on mediating oxidase-like activity by means of constructing isostructural HOFs. We discover that the HOF pore with suitable geometry can stabilize and spatially organize the catalytic substrate into a favorable catalytic route, as with the function of the native enzyme pocket. Based on the desirable photo-responsive oxidase-like activity, a visual and sensitive HOFs biosensor is established for the detection of phosphatase, an important biomarker of skeletal and hepatobiliary diseases. This work demonstrates that the pore environments significantly influence the nanozymes' activity in addition to the active center.
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Affiliation(s)
- Linjing Tong
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yuhong Lin
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China
| | - Xiaoxue Kou
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yujian Shen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yong Shen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China
| | - Siming Huang
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, 511436, China
| | - Fang Zhu
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China
| | - Guosheng Chen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China
| | - Gangfeng Ouyang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China
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8
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Li S, Shi J, Liu S, Li W, Chen Y, Shan H, Cheng Y, Wu H, Jiang Z. Molecule-electron-proton transfer in enzyme-photo-coupled catalytic system. CHINESE JOURNAL OF CATALYSIS 2023. [DOI: 10.1016/s1872-2067(22)64154-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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9
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Taylor A, Heyes DJ, Scrutton NS. Catalysis by Nature's photoenzymes. Curr Opin Struct Biol 2022; 77:102491. [PMID: 36323132 DOI: 10.1016/j.sbi.2022.102491] [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: 03/18/2022] [Revised: 08/22/2022] [Accepted: 10/01/2022] [Indexed: 12/14/2022]
Abstract
Photoenzymes use light to initiate biochemical reactions. Although rarely found in nature, their study has advanced understanding of how light energy can be harnessed to facilitate enzyme catalysis, which is also of importance to the design and engineering of man-made photocatalysts. Natural photoenzymes can be assigned to one of two families, based broadly on the nature of the light-sensing chromophores used, those being chlorophyll-like tetrapyrroles or flavins. In all cases, light absorption leads to excited state electron transfer, which in turn initiates photocatalysis. Reviewed here are recent findings relating to the structures and mechanisms of known photoenzymes. We highlight recent advances that have deepened understanding of mechanisms in biological photocatalysis.
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Affiliation(s)
- Aoife Taylor
- Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, The University of Manchester, M1 7DN, United Kingdom
| | - Derren J Heyes
- Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, The University of Manchester, M1 7DN, United Kingdom. https://twitter.com/DerrenHeyes
| | - Nigel S Scrutton
- Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, The University of Manchester, M1 7DN, United Kingdom.
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10
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Bettendorff L. Reduced Nucleotides, Thiols and O 2 in Cellular Redox Balance: A Biochemist's View. Antioxidants (Basel) 2022; 11:1877. [PMID: 36290600 PMCID: PMC9598635 DOI: 10.3390/antiox11101877] [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: 07/28/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 07/30/2023] Open
Abstract
In the present review, which is aimed at researchers, teachers and students in life sciences, we try to show how the physicochemical properties of the elements and molecules define the concept of redox balance. Living organism are open systems traversed by fluxes of energy and matter. During catabolic oxidative metabolism, matter-mostly hydrogenated organic molecules-is oxidized and ultimately released as CO2. Electrons are passed over to coupling molecules, such as NAD+ and FAD, whose reduced forms serve as electrons donors in anabolic reactions. Early photosynthetic activity led to the accumulation of O2 and the transformation of the reduction to an oxidizing atmosphere, favoring the development of oxidative metabolism in living organisms. We focus on the specific properties of O2 that provide the chemical energy for the combustion reactions occurring in living cells. We explain the concepts of redox potential and redox balance in complex systems such as living cells, we present the main redox couples involved in cellular redox balance and we discuss the chemical properties underlying their cellular roles and, in particular, their antioxidant properties in the defense against reactive oxygen species (ROS). Finally, we try to provide an integrative view emphasizing the interplay between metabolism, oxidative stress and metabolic compartmentation in mammalian cells.
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Affiliation(s)
- Lucien Bettendorff
- Laboratory of Neurophysiology, GIGA Neurosciences, University of Liège, 4000 Liège, Belgium
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11
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Mikshiev VY, Tolstoy PM, Puzyk AM, Kirichenko SO, Antonov AS. peri-Interactions in 1,8-bis(dimethylamino)naphthalene ortho-ketimine cations facilitate [1,5]-hydride shift: selective synthesis of 1,2,3,4-tetrahydrobenzo[ h]quinazolines. Org Biomol Chem 2022; 20:4559-4568. [PMID: 35593098 DOI: 10.1039/d2ob00674j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Selective heterocyclization leading to 1,2,3,4-tetrahydrobenzo[h]quinazolines from ortho-ketimines of 1,8-bis(dimethylamino)naphthalene (DmanIms) under acid catalysis has been revealed. In contrast to the rather unreactive N,N-dimethylaniline ortho-ketimine, DmanIms readily undergo this transformation without an additional catalyst. This distinction in the reactivity underscores the importance of the second peri-NMe2 group in DmanIms, which facilitates a [1,5]-hydride shift and the subsequent cyclization. The cascade of peri-interactions emerging between 1-NMe2 and 8-NMe2 groups has been identified as a reason for the catalytic effect: (1) the hydrogen bond in the DmanIm dication constrains 1-NMe2 in the desired position providing proximity of reaction centers, (2) the repulsion of the lone pairs of 8-NMe2 group and unrelaxed 1-NMe2 group arising right after deprotonation process reduces the Gibbs free energy of activation (ΔG‡) for the straight hydride shift, and (3) the electrostatic interaction between 8-NMe2 and the charged NCH2+ group in the intermediate increases the ΔG‡ for the reverse hydride shift.
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Affiliation(s)
- Vladimir Y Mikshiev
- Institute of Chemistry, St Petersburg State University, Universitetskij pr. 26, 198504 St Petersburg, Russian Federation.
| | - Peter M Tolstoy
- Institute of Chemistry, St Petersburg State University, Universitetskij pr. 26, 198504 St Petersburg, Russian Federation.
| | - Aleksandra M Puzyk
- Institute of Chemistry, St Petersburg State University, Universitetskij pr. 26, 198504 St Petersburg, Russian Federation.
| | - Sergey O Kirichenko
- Institute of Chemistry, St Petersburg State University, Universitetskij pr. 26, 198504 St Petersburg, Russian Federation.
| | - Alexander S Antonov
- Institute of Chemistry, St Petersburg State University, Universitetskij pr. 26, 198504 St Petersburg, Russian Federation.
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12
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Johannissen LO, Taylor A, Hardman SJ, Heyes DJ, Scrutton NS, Hay S. How Photoactivation Triggers Protochlorophyllide Reduction: Computational Evidence of a Stepwise Hydride Transfer during Chlorophyll Biosynthesis. ACS Catal 2022; 12:4141-4148. [PMID: 35574213 PMCID: PMC9098174 DOI: 10.1021/acscatal.2c00866] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/08/2022] [Indexed: 12/28/2022]
Abstract
The photochemical reaction catalyzed by enzyme protochlorophyllide oxidoreductase (POR), a rare example of a photoactivated enzyme, is a crucial step during chlorophyll biosynthesis and involves the fastest known biological hydride transfer. Structures of the enzyme with bound substrate protochlorophyllide (PChlide) and coenzyme nicotinamide adenine dinucleotide phosphate (NADPH) have recently been published, opening up the possibility of using computational approaches to provide a comprehensive understanding of the excited state chemistry. Herein, we propose a complete mechanism for the photochemistry between PChlide and NADPH based on density functional theory (DFT) and time-dependent DFT calculations that is consistent with recent experimental data. In this multi-step mechanism, photoexcitation of PChlide leads to electron transfer from NADPH to PChlide, which in turn facilitates hydrogen atom transfer by weakening the breaking C-H bond. This work rationalizes how photoexcitation facilitates hydride transfer in POR and has more general implications for biological hydride transfer reactions.
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Affiliation(s)
- Linus O. Johannissen
- Manchester Institute of Biotechnology
and Department of Chemistry, The University
of Manchester, Manchester M1 7DN, U.K.
| | - Aoife Taylor
- Manchester Institute of Biotechnology
and Department of Chemistry, The University
of Manchester, Manchester M1 7DN, U.K.
| | - Samantha J.O. Hardman
- Manchester Institute of Biotechnology
and Department of Chemistry, The University
of Manchester, Manchester M1 7DN, U.K.
| | - Derren J. Heyes
- Manchester Institute of Biotechnology
and Department of Chemistry, The University
of Manchester, Manchester M1 7DN, U.K.
| | - Nigel S. Scrutton
- Manchester Institute of Biotechnology
and Department of Chemistry, The University
of Manchester, Manchester M1 7DN, U.K.
| | - Sam Hay
- Manchester Institute of Biotechnology
and Department of Chemistry, The University
of Manchester, Manchester M1 7DN, U.K.
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13
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Silva PJ, Cheng Q. An Alternative Proposal for the Reaction Mechanism of Light-Dependent Protochlorophyllide Oxidoreductase. ACS Catal 2022; 12:2589-2605. [PMID: 36568346 PMCID: PMC9778109 DOI: 10.1021/acscatal.1c05351] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Light-dependent protochlorophyllide oxidoreductase is one of the few known enzymes that require a quantum of light to start their catalytic cycle. Upon excitation, it uses NADPH to reduce the C17-C18 in its substrate (protochlorophyllide) through a complex mechanism that has heretofore eluded precise determination. Isotopic labeling experiments have shown that the hydride-transfer step is very fast, with a small barrier close to 9 kcal mol-1, and is followed by a proton-transfer step, which has been postulated to be the protonation of the product by the strictly conserved Tyr189 residue. Since the structure of the enzyme-substrate complex has not yet been experimentally determined, we first used modeling techniques to discover the actual substrate binding mode. Two possible binding modes were found, both yielding stable binding (as ascertained through molecular dynamics simulations) but only one of which placed the critical C17=C18 bond consistently close to the NADPH pro-S hydrogen and to Tyr189. This binding pose was then used as a starting point for the testing of previous mechanistic proposals using time-dependent density functional theory. The quantum-chemical computations clearly showed that such mechanisms have prohibitively high activation energies. Instead, these computations showed the feasibility of an alternative mechanism initiated by excited-state electron transfer from the key Tyr189 to the substrate. This mechanism appears to agree with the extant experimental data and reinterprets the final protonation step as a proton transfer to the active site itself rather than to the product, aiming at regenerating it for another round of catalysis.
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Affiliation(s)
- Pedro J. Silva
- FP-I3ID/Fac.
de Ciências da Saúde, Universidade
Fernando Pessoa, 4200-150 Porto, Portugal,UCIBIO@REQUIMTE,
BioSIM, Departamento de Biomedicina, Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, Portugal,
| | - Qi Cheng
- Department
of Biochemistry, College of Life Sciences, Hebei Agricultural University, Baoding, Hebei 071000, China,State
Key Laboratory of North China Crop Improvement and Regulation, Hebei Agricultural University, Baoding, Hebei 071000, China,
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14
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Poddar H, Heyes DJ, Schirò G, Weik M, Leys D, Scrutton NS. A guide to time-resolved structural analysis of light-activated proteins. FEBS J 2021; 289:576-595. [PMID: 33864718 DOI: 10.1111/febs.15880] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/03/2021] [Accepted: 04/13/2021] [Indexed: 01/08/2023]
Abstract
Dynamical changes in protein structures are essential for protein function and occur over femtoseconds to seconds timescales. X-ray free electron lasers have facilitated investigations of structural dynamics in proteins with unprecedented temporal and spatial resolution. Light-activated proteins are attractive targets for time-resolved structural studies, as the reaction chemistry and associated protein structural changes can be triggered by short laser pulses. Proteins with different light-absorbing centres have evolved to detect light and harness photon energy to bring about downstream chemical and biological output responses. Following light absorption, rapid chemical/small-scale structural changes are typically localised around the chromophore. These localised changes are followed by larger structural changes propagated throughout the photoreceptor/photocatalyst that enables the desired chemical and/or biological output response. Time-resolved serial femtosecond crystallography (SFX) and solution scattering techniques enable direct visualisation of early chemical change in light-activated proteins on timescales previously inaccessible, whereas scattering gives access to slower timescales associated with more global structural change. Here, we review how advances in time-resolved SFX and solution scattering techniques have uncovered mechanisms of photochemistry and its coupling to output responses. We also provide a prospective on how these time-resolved structural approaches might impact on other photoreceptors/photoenzymes that have not yet been studied by these methods.
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Affiliation(s)
- Harshwardhan Poddar
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, UK
| | - Derren J Heyes
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, UK
| | - Giorgio Schirò
- Institut de Biologie Structurale, Univ. Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Martin Weik
- Institut de Biologie Structurale, Univ. Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - David Leys
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, UK
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, UK
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15
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Overview of structurally homologous flavoprotein oxidoreductases containing the low M r thioredoxin reductase-like fold - A functionally diverse group. Arch Biochem Biophys 2021; 702:108826. [PMID: 33684359 DOI: 10.1016/j.abb.2021.108826] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/23/2021] [Accepted: 02/27/2021] [Indexed: 01/12/2023]
Abstract
Structural studies show that enzymes have a limited number of unique folds, although structurally related enzymes have evolved to perform a large variety of functions. In this review, we have focused on enzymes containing the low molecular weight thioredoxin reductase (low Mr TrxR) fold. This fold consists of two domains, both containing a three-layer ββα sandwich Rossmann-like fold, serving as flavin adenine dinucleotide (FAD) and, in most cases, pyridine nucleotide (NAD(P)H) binding-domains. Based on a search of the Protein Data Bank for all published structures containing the low Mr TrxR-like fold, we here present a comprehensive overview of enzymes with this structural architecture. These range from TrxR-like ferredoxin/flavodoxin NAD(P)+ oxidoreductases, through glutathione reductase, to NADH peroxidase. Some enzymes are solely composed of the low Mr TrxR-like fold, while others contain one or two additional domains. In this review, we give a detailed description of selected enzymes containing only the low Mr TrxR-like fold, however, catalyzing a diversity of chemical reactions. Our overview of this structurally similar, yet functionally distinct group of flavoprotein oxidoreductases highlights the fascinating and increasing number of studies describing the diversity among these enzymes, especially during the last decade(s).
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16
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Heyes DJ, Zhang S, Taylor A, Johannissen LO, Hardman SJO, Hay S, Scrutton NS. Photocatalysis as the 'master switch' of photomorphogenesis in early plant development. NATURE PLANTS 2021; 7:268-276. [PMID: 33686224 DOI: 10.1038/s41477-021-00866-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 01/29/2021] [Indexed: 06/12/2023]
Abstract
Enzymatic photocatalysis is seldom used in biology. Photocatalysis by light-dependent protochlorophyllide oxidoreductase (LPOR)-one of only a few natural light-dependent enzymes-is an exception, and is responsible for the conversion of protochlorophyllide to chlorophyllide in chlorophyll biosynthesis. Photocatalysis by LPOR not only regulates the biosynthesis of the most abundant pigment on Earth but it is also a 'master switch' in photomorphogenesis in early plant development. Following illumination, LPOR promotes chlorophyll production, plastid membranes are transformed and the photosynthetic apparatus is established. Given these remarkable, light-induced pigment and morphological changes, the LPOR-catalysed reaction has been extensively studied from catalytic, physiological and plant development perspectives, highlighting vital, and multiple, cellular roles of this intriguing enzyme. Here, we offer a perspective in which the link between LPOR photocatalysis and plant photomorphogenesis is explored. Notable breakthroughs in LPOR structural biology have uncovered the structural-mechanistic basis of photocatalysis. These studies have clarified how photon absorption by the pigment protochlorophyllide-bound in a ternary LPOR-protochlorophyllide-NADPH complex-triggers photocatalysis and a cascade of complex molecular and cellular events that lead to plant morphological changes. Photocatalysis is therefore the master switch responsible for early-stage plant development and ultimately life on Earth.
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Affiliation(s)
- Derren J Heyes
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, The University of Manchester, Manchester, UK.
| | - Shaowei Zhang
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, The University of Manchester, Manchester, UK
| | - Aoife Taylor
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, The University of Manchester, Manchester, UK
| | - Linus O Johannissen
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, The University of Manchester, Manchester, UK
| | - Samantha J O Hardman
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, The University of Manchester, Manchester, UK
| | - Sam Hay
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, The University of Manchester, Manchester, UK
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, Department of Chemistry, School of Natural Sciences, The University of Manchester, Manchester, UK.
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17
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Conformation of the Intermediates in the Reaction Catalyzed by Protoporphyrinogen Oxidase: An In Silico Analysis. Int J Mol Sci 2020; 21:ijms21249495. [PMID: 33327448 PMCID: PMC7764921 DOI: 10.3390/ijms21249495] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 12/29/2022] Open
Abstract
Protoporphyrinogen oxidase (PPO) is a critical enzyme across life as the last common step in the synthesis of many metalloporphyrins. The reaction mechanism of PPO was assessed in silico and the unstructured loop near the binding pocket was investigated. The substrate, intermediates, and product were docked in the catalytic domain of PPO using a modified Autodock method, introducing flexibility in the macrocycles. Sixteen PPO protein sequences across phyla were aligned and analyzed with Phyre2 and ProteinPredict to study the unstructured loop from residue 204–210 in the H. sapiens structure. Docking of the substrate, intermediates, and product all resulted in negative binding energies, though the substrate had a lower energy than the others by 40%. The α-H of C10 was found to be 1.4 angstroms closer to FAD than the β-H, explaining previous reports of the reaction occurring on the meso face of the substrate. A lack of homology in sequence or length in the unstructured loop indicates a lack of function for the protein reaction. This docking study supports a reaction mechanism proposed previously whereby all hydride abstractions occur on the C10 of the tetrapyrrole followed by tautomeric rearrangement to prepare the intermediate for the next reaction.
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18
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Zhang S, Godwin ARF, Taylor A, Hardman SJO, Jowitt TA, Johannissen LO, Hay S, Baldock C, Heyes DJ, Scrutton NS. Dual role of the active site 'lid' regions of protochlorophyllide oxidoreductase in photocatalysis and plant development. FEBS J 2020; 288:175-189. [PMID: 32866986 DOI: 10.1111/febs.15542] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/15/2020] [Accepted: 08/24/2020] [Indexed: 11/29/2022]
Abstract
Protochlorophyllide oxidoreductase (POR) catalyses reduction of protochlorophyllide (Pchlide) to chlorophyllide, a light-dependent reaction of chlorophyll biosynthesis. POR is also important in plant development as it is the main constituent of prolamellar bodies in etioplast membranes. Prolamellar bodies are highly organised, paracrystalline structures comprising aggregated oligomeric structures of POR-Pchlide-NADPH complexes. How these oligomeric structures are formed and the role of Pchlide in oligomerisation remains unclear. POR crystal structures highlight two peptide regions that form a 'lid' to the active site, and undergo conformational change on binding Pchlide. Here, we show that Pchlide binding triggers formation of large oligomers of POR using size exclusion chromatography. A POR 'octamer' has been isolated and its structure investigated by cryo-electron microscopy at 7.7 Å resolution. This structure shows that oligomer formation is most likely driven by the interaction of amino acid residues in the highly conserved lid regions. Computational modelling indicates that Pchlide binding stabilises exposure of hydrophobic surfaces formed by the lid regions, which supports POR dimerisation and ultimately oligomer formation. Studies with variant PORs demonstrate that lid residues are involved in substrate binding and photocatalysis. These highly conserved lid regions therefore have a dual function. The lid residues position Pchlide optimally to enable photocatalysis. Following Pchlide binding, they also enable POR oligomerisation - a process that is reversed through subsequent photocatalysis in the early stages of chloroplast development.
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Affiliation(s)
- Shaowei Zhang
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Department of Chemistry, Faculty of Science and Engineering, School of Natural Sciences, The University of Manchester, UK
| | - Alan R F Godwin
- Wellcome Centre for Cell-Matrix Research, University of Manchester, UK.,Division of Cell-Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, UK
| | - Aoife Taylor
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Department of Chemistry, Faculty of Science and Engineering, School of Natural Sciences, The University of Manchester, UK
| | - Samantha J O Hardman
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Department of Chemistry, Faculty of Science and Engineering, School of Natural Sciences, The University of Manchester, UK
| | - Thomas A Jowitt
- Wellcome Centre for Cell-Matrix Research, University of Manchester, UK.,Division of Cell-Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, UK
| | - Linus O Johannissen
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Department of Chemistry, Faculty of Science and Engineering, School of Natural Sciences, The University of Manchester, UK
| | - Sam Hay
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Department of Chemistry, Faculty of Science and Engineering, School of Natural Sciences, The University of Manchester, UK
| | - Clair Baldock
- Wellcome Centre for Cell-Matrix Research, University of Manchester, UK.,Division of Cell-Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, UK
| | - Derren J Heyes
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Department of Chemistry, Faculty of Science and Engineering, School of Natural Sciences, The University of Manchester, UK
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, The University of Manchester, UK.,Department of Chemistry, Faculty of Science and Engineering, School of Natural Sciences, The University of Manchester, UK
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19
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Schmermund L, Bierbaumer S, Schein VK, Winkler CK, Kara S, Kroutil W. Extending the Library of Light‐Dependent Protochlorophyllide Oxidoreductases and their Solvent Tolerance, Stability in Light and Cofactor Flexibility. ChemCatChem 2020. [DOI: 10.1002/cctc.202000561] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Luca Schmermund
- Institute of Chemistry University of Graz – Field of Excellence BioHealth NAWI Graz BioTechMed Graz Heinrichstrasse 28 8010 Graz Austria
| | - Sarah Bierbaumer
- Institute of Chemistry University of Graz – Field of Excellence BioHealth NAWI Graz BioTechMed Graz Heinrichstrasse 28 8010 Graz Austria
| | - Viktor K. Schein
- Institute of Chemistry University of Graz – Field of Excellence BioHealth NAWI Graz BioTechMed Graz Heinrichstrasse 28 8010 Graz Austria
| | - Christoph K. Winkler
- Institute of Chemistry University of Graz – Field of Excellence BioHealth NAWI Graz BioTechMed Graz Heinrichstrasse 28 8010 Graz Austria
| | - Selin Kara
- Department of Engineering Biological and Chemical Engineering Biocatalysis and Bioprocessing Group Aarhus University Gustav Wieds Vej 10 8000 Aarhus Denmark
| | - Wolfgang Kroutil
- Institute of Chemistry University of Graz – Field of Excellence BioHealth NAWI Graz BioTechMed Graz Heinrichstrasse 28 8010 Graz Austria
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20
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Abstract
Modified tetrapyrroles are large macrocyclic compounds, consisting of diverse conjugation and metal chelation systems and imparting an array of colors to the biological structures that contain them. Tetrapyrroles represent some of the most complex small molecules synthesized by cells and are involved in many essential processes that are fundamental to life on Earth, including photosynthesis, respiration, and catalysis. These molecules are all derived from a common template through a series of enzyme-mediated transformations that alter the oxidation state of the macrocycle and also modify its size, its side-chain composition, and the nature of the centrally chelated metal ion. The different modified tetrapyrroles include chlorophylls, hemes, siroheme, corrins (including vitamin B12), coenzyme F430, heme d1, and bilins. After nearly a century of study, almost all of the more than 90 different enzymes that synthesize this family of compounds are now known, and expression of reconstructed operons in heterologous hosts has confirmed that most pathways are complete. Aside from the highly diverse nature of the chemical reactions catalyzed, an interesting aspect of comparative biochemistry is to see how different enzymes and even entire pathways have evolved to perform alternative chemical reactions to produce the same end products in the presence and absence of oxygen. Although there is still much to learn, our current understanding of tetrapyrrole biogenesis represents a remarkable biochemical milestone that is summarized in this review.
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Affiliation(s)
- Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Martin J Warren
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom
- Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, United Kingdom
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21
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Crystal structures of cyanobacterial light-dependent protochlorophyllide oxidoreductase. Proc Natl Acad Sci U S A 2020; 117:8455-8461. [PMID: 32234783 DOI: 10.1073/pnas.1920244117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The reduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide) is the penultimate step of chlorophyll biosynthesis. In oxygenic photosynthetic bacteria, algae, and plants, this reaction can be catalyzed by the light-dependent Pchlide oxidoreductase (LPOR), a member of the short-chain dehydrogenase superfamily sharing a conserved Rossmann fold for NAD(P)H binding and the catalytic activity. Whereas modeling and simulation approaches have been used to study the catalytic mechanism of this light-driven reaction, key details of the LPOR structure remain unclear. We determined the crystal structures of LPOR from two cyanobacteria, Synechocystis sp. PCC 6803 and Thermosynechococcus elongatus Structural analysis defines the LPOR core fold, outlines the LPOR-NADPH interaction network, identifies the residues forming the substrate cavity and the proton-relay path, and reveals the role of the LPOR-specific loop. These findings provide a basis for understanding the structure-function relationships of the light-driven Pchlide reduction.
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22
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Biswas S, Bhattacharya I, Chakraborty T. Identification of an Emitting Metastable State of p-Fluorophenol-Ammonia 1:2 Complex by Laser-Induced Fluorescence Spectroscopy. J Phys Chem A 2019; 123:10563-10570. [PMID: 31714082 DOI: 10.1021/acs.jpca.9b07958] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have demonstrated here, for the first time to our knowledge, the formation of an emitting metastable species upon lowest electronic excitation (S1) of a hydrogen-bonded 1:2 complex of para-fluorophenol (pFP) with ammonia (NH3), which is known to be one of the smallest reactive complexes to undergo excited state H-atom transfer (HAT) reaction to produce •NH4(NH3) radical fragment. The emission spectrum of the species is characterized to be red-shifted, broad, and structureless. From the viewpoint of energy balance, an excited state proton transfer (ESPT) is unfavorable, but according to predicted electronic structure parameters, the metastable state species could be stabilized by charge transfer (CT) interaction at the hydrogen-bonded geometry of the complex. We propose that this species could act as an intermediate to the HAT process in the excited state. The observation of such a state could be valuable to understand the complex dynamics of similar events in biologically relevant systems.
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Affiliation(s)
- Souvick Biswas
- School of Chemical Sciences , Indian Association for the Cultivation of Science , 2A Raja S C Mullick Road, Jadavpur , Kolkata 700032 , India
| | - Indrani Bhattacharya
- School of Chemical Sciences , Indian Association for the Cultivation of Science , 2A Raja S C Mullick Road, Jadavpur , Kolkata 700032 , India
| | - Tapas Chakraborty
- School of Chemical Sciences , Indian Association for the Cultivation of Science , 2A Raja S C Mullick Road, Jadavpur , Kolkata 700032 , India
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23
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Lin Z, Xiong Y, Xue Y, Mao M, Xiang Y, He Y, Rafique F, Hu H, Liu J, Li X, Sun L, Huang Z, Ma J. Screening and characterization of long noncoding RNAs involved in the albinism of Ananas comosus var. bracteatus leaves. PLoS One 2019; 14:e0225602. [PMID: 31756232 PMCID: PMC6874346 DOI: 10.1371/journal.pone.0225602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 11/08/2019] [Indexed: 12/19/2022] Open
Abstract
Long noncoding RNAs (lncRNAs) have been reported to play key regulatory roles in plant growth, development, and biotic and abiotic stress physiology. Revealing the mechanism of lncRNA regulation in the albino portions of leaves is important for understanding the development of chimeric leaves in Ananas comosus var. bracteatus. In this study, a total of 3,543 candidate lncRNAs were identified, among which 1,451 were differentially expressed between completely green (CGr) and completely white (CWh) leaves. LncRNAs tend to have shorter transcripts, lower expression levels, and greater expression specificity than protein-coding genes. Predicted lncRNA targets were functionally annotated by the Gene Ontology (GO), Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. A lncRNA-mRNA interaction network was constructed, and 36 target mRNAs related to chlorophyll metabolism were predicted to interact with 86 lncRNAs. Among these, 25 significantly differentially expressed lncRNAs putatively interacted with 16 target mRNAs. Based on an expression pattern analysis of the lncRNAs and their target mRNAs, the lncRNAs targeting magnesium chelatase subunit H (ChlH), protochlorophyllide oxidoreductase (POR), and heme o synthase (COX10) were suggested as key regulators of chlorophyll metabolism. This study provides the first lncRNA database for A. comosus var. bracteatus and contributes greatly to understanding the mechanism of epigenetic regulation of leaf albinism.
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Affiliation(s)
- Zhen Lin
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yingyuan Xiong
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yanbin Xue
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Meiqin Mao
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yixuan Xiang
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yehua He
- Horticultural Biotechnology College of South China Agricultural University, Guangzhou, Guangdong, China
| | - Fatima Rafique
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Hao Hu
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Jiawen Liu
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xi Li
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Lingxia Sun
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Zhuo Huang
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Jun Ma
- College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan, China
- * E-mail:
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24
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Angelastro A, Ruiz-Pernía JJ, Tuñón I, Moliner V, Luk LYP, Allemann RK. Loss of Hyperconjugative Effects Drives Hydride Transfer during Dihydrofolate Reductase Catalysis. ACS Catal 2019; 9:10343-10349. [PMID: 32051770 PMCID: PMC7007191 DOI: 10.1021/acscatal.9b02839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/20/2019] [Indexed: 02/06/2023]
Abstract
![]()
Hydride transfer
is widespread in nature and has an essential role
in applied research. However, the mechanisms of how this transformation
occurs in living organisms remain a matter of vigorous debate. Here,
we examined dihydrofolate reductase (DHFR), an enzyme that catalyzes
hydride from C4′ of NADPH to C6 of 7,8-dihydrofolate (H2F). Despite many investigations of the mechanism of this reaction,
the contribution of polarization of the π-bond of H2F in driving hydride transfer remains unclear. H2F was
stereospecifically labeled with deuterium β to the reacting
center, and β-deuterium kinetic isotope effects were measured.
Our experimental results combined with analysis derived from QM/MM
simulations reveal that hydride transfer is triggered by polarization
at the C6 of H2F. The σ Cβ–H
bonds contribute to the buildup of the cationic character during the
chemical transformation, and hyperconjugation influences the formation
of the transition state. Our findings provide key insights into the
hydride transfer mechanism of the DHFR-catalyzed reaction, which is
a target for antiproliferative drugs and a paradigmatic model in mechanistic
enzymology.
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Affiliation(s)
- Antonio Angelastro
- School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, United Kingdom
| | | | - Iñaki Tuñón
- Departament de Química Física, Universitat de València, 46100 Burjassot, Spain
| | - Vicent Moliner
- Departament de Química Física i Analítica, Universitat Jaume I, 12071 Castelló, Spain
| | - Louis Y. P. Luk
- School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, United Kingdom
| | - Rudolf K. Allemann
- School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, United Kingdom
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25
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Structural basis for enzymatic photocatalysis in chlorophyll biosynthesis. Nature 2019; 574:722-725. [PMID: 31645759 DOI: 10.1038/s41586-019-1685-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/25/2019] [Indexed: 12/26/2022]
Abstract
The enzyme protochlorophyllide oxidoreductase (POR) catalyses a light-dependent step in chlorophyll biosynthesis that is essential to photosynthesis and, ultimately, all life on Earth1-3. POR, which is one of three known light-dependent enzymes4,5, catalyses reduction of the photosensitizer and substrate protochlorophyllide to form the pigment chlorophyllide. Despite its biological importance, the structural basis for POR photocatalysis has remained unknown. Here we report crystal structures of cyanobacterial PORs from Thermosynechococcus elongatus and Synechocystis sp. in their free forms, and in complex with the nicotinamide coenzyme. Our structural models and simulations of the ternary protochlorophyllide-NADPH-POR complex identify multiple interactions in the POR active site that are important for protochlorophyllide binding, photosensitization and photochemical conversion to chlorophyllide. We demonstrate the importance of active-site architecture and protochlorophyllide structure in driving POR photochemistry in experiments using POR variants and protochlorophyllide analogues. These studies reveal how the POR active site facilitates light-driven reduction of protochlorophyllide by localized hydride transfer from NADPH and long-range proton transfer along structurally defined proton-transfer pathways.
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Schneidewind J, Krause F, Bocola M, Stadler AM, Davari MD, Schwaneberg U, Jaeger KE, Krauss U. Consensus model of a cyanobacterial light-dependent protochlorophyllide oxidoreductase in its pigment-free apo-form and photoactive ternary complex. Commun Biol 2019; 2:351. [PMID: 31583285 PMCID: PMC6761149 DOI: 10.1038/s42003-019-0590-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/29/2019] [Indexed: 12/02/2022] Open
Abstract
Photosynthetic organisms employ two different enzymes for the reduction of the C17 = C18 double bond of protochlorophyllide (Pchlide), yielding the chlorophyll precursor chlorophyllide. First, a nitrogenase-like, light-independent (dark-operative) Pchlide oxidoreductase and secondly, a light-dependent Pchlide oxidoreductase (LPOR). For the latter enzyme, despite decades of research, no structural information is available. Here, we use protein structure modelling, molecular dynamics (MD) simulations combined with multi-wavelength analytical ultracentrifugation (MWA-AUC) and small angle X-ray scattering (SAXS) experiments to derive a consensus model of the LPOR apoprotein and the substrate/cofactor/LPOR ternary complex. MWA-AUC and SAXS experiments independently demonstrate that the apoprotein is monomeric, while ternary complex formation induces dimerization. SAXS-guided modelling studies provide a full-length model of the apoprotein and suggest a tentative mode of dimerization for the LPOR ternary complex, supported by published cross-link constraints. Our study provides a first impression of the LPOR structural organization.
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Affiliation(s)
- Judith Schneidewind
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Frank Krause
- Nanolytics, Gesellschaft für Kolloidanalytik GmbH, Am Mühlenberg 11, 14476 Potsdam, Germany
| | - Marco Bocola
- Lehrstuhl für Biotechnologie, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Andreas Maximilian Stadler
- Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany
| | - Mehdi D. Davari
- Lehrstuhl für Biotechnologie, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
| | - Ulrich Schwaneberg
- Lehrstuhl für Biotechnologie, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
- DWI-Leibniz Institut für Interaktive Materialien, Forckenbeckstraße 50, 52056 Aachen, Germany
| | - Karl-Erich Jaeger
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
- IBG-1: Biotechnologie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Ulrich Krauss
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
- IBG-1: Biotechnologie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
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Stadler AM, Schneidewind J, Zamponi M, Knieps-Grünhagen E, Gholami S, Schwaneberg U, Rivalta I, Garavelli M, Davari MD, Jaeger KE, Krauss U. Ternary Complex Formation and Photoactivation of a Photoenzyme Results in Altered Protein Dynamics. J Phys Chem B 2019; 123:7372-7384. [PMID: 31380636 DOI: 10.1021/acs.jpcb.9b06608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interplay between protein dynamics and catalysis remains a fundamental question in enzymology. We here investigate the ns-timescale dynamics of a light-dependent NADPH:protochlorophyllide oxidoreductase (LPOR), a photoenzyme crucial for chlorophyll synthesis. LPORs catalyze the light-triggered trans addition of a hydride and a proton across the C17═C18 double bond of the chlorophyll precursor protochlorophyllide (Pchlide). Because of the lack of an LPOR structure, the global structural and dynamic consequences of LPOR/Pchlide/NADPH ternary complex formation remain elusive. Moreover, photoactivation of LPORs by low-light preillumination is controversially discussed as unequivocal proof for this phenomenon is lacking. By employing quasielastic neutron spectroscopy (QENS), we show that the formation of the ternary holoprotein complex as well as photoactivation lead to progressive rigidification of the protein. These findings are supported by thermostability measurements, which reveal different melting behavior and thermostabilities for the apo- and holoprotein ternary complexes. Molecular dynamics simulations in good agreement with the experimental QENS results suggest that the increased flexibility observed for the apoprotein stems from structural fluctuations of the NADPH and Pchlide substrate binding sites of the enzyme. On the basis of our results, in conjunction with activity and stability measurements, we provide independent proof for LPOR photoactivation, defined as a process that modifies the protein structure and dynamics, resulting in an increased substrate turnover. Our findings advance the structural and dynamic understanding of LPORs and provide a first link between protein dynamics and catalysis for this enzyme class.
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Affiliation(s)
| | | | - Michaela Zamponi
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) , Forschungszentrum Jülich GmbH , Lichtenbergstr. 1 , 85748 Garching , Germany
| | | | - Samira Gholami
- Dipartimento di Chimica Industriale , Università degli Studi di Bologna , Viale del Risorgimento 4 , I-40136 Bologna , Italy
| | - Ulrich Schwaneberg
- Institute of Biotechnology , RWTH Aachen University , Worringer Weg 3 , D-52074 Aachen , Germany.,DWI-Leibniz Institute for Interactive Materials , Forckenbeckstraße 50 , 52056 Aachen , Germany
| | - Ivan Rivalta
- Université de Lyon, École Normale Supérieure de Lyon, CNRS, Université Claude Bernard Lyon 1, Laboratoire de Chimie UMR 5182 , F-69342 Lyon , France
| | - Marco Garavelli
- Dipartimento di Chimica Industriale , Università degli Studi di Bologna , Viale del Risorgimento 4 , I-40136 Bologna , Italy.,École Normale Supérieure de Lyon, CNRS, Laboratoire de Chimie UMR 5182, Université de Lyon , 46 Allée d'Italie , F-69364 Lyon Cedex 07 , France
| | - Mehdi D Davari
- Institute of Biotechnology , RWTH Aachen University , Worringer Weg 3 , D-52074 Aachen , Germany
| | - Karl-Erich Jaeger
- IBG-1: Biotechnologie , Forschungszentrum Jülich GmbH , D-52425 Jülich , Germany
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Schmermund L, Jurkaš V, Özgen FF, Barone GD, Büchsenschütz HC, Winkler CK, Schmidt S, Kourist R, Kroutil W. Photo-Biocatalysis: Biotransformations in the Presence of Light. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00656] [Citation(s) in RCA: 147] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Luca Schmermund
- Institute of Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, BioHealth, Heinrichstrasse 28, 8010 Graz, Austria
| | - Valentina Jurkaš
- Institute of Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, BioHealth, Heinrichstrasse 28, 8010 Graz, Austria
| | - F. Feyza Özgen
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, Petersgasse 14, 8010 Graz, Austria
| | - Giovanni D. Barone
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, Petersgasse 14, 8010 Graz, Austria
| | - Hanna C. Büchsenschütz
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, Petersgasse 14, 8010 Graz, Austria
| | - Christoph K. Winkler
- Institute of Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, BioHealth, Heinrichstrasse 28, 8010 Graz, Austria
| | - Sandy Schmidt
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, Petersgasse 14, 8010 Graz, Austria
| | - Robert Kourist
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, Petersgasse 14, 8010 Graz, Austria
| | - Wolfgang Kroutil
- Institute of Chemistry, University of Graz, NAWI Graz, BioTechMed Graz, BioHealth, Heinrichstrasse 28, 8010 Graz, Austria
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Erdei AL, Kósa A, Böddi B. Distinct UV-A or UV-B irradiation induces protochlorophyllide photoreduction and bleaching in dark-grown pea (Pisum sativum L.) epicotyls. PHOTOSYNTHESIS RESEARCH 2019; 140:93-102. [PMID: 30225812 DOI: 10.1007/s11120-018-0584-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 09/12/2018] [Indexed: 06/08/2023]
Abstract
The effects of distinct UV-A and UV-B radiations were studied on etiolated pea (Pisum sativum L.) epicotyls. Emission spectra of the native protochlorophyll and protochlorophyllide forms were measured when epicotyls were excited with 360 or 300 nm light. The UV-A (360 nm) excited mainly the non-enzyme-bound monomers of protochlorophyll and protochlorophyllide and the UV-B (300 nm) excited preferentially the flash-photoactive protochlorophyllide complexes. These latter complexes converted into short- and long-wavelength chlorophyllide forms at 10-s illumination with both wavelength irradiations. As the spectral changes were very small, the effects of longer illumination periods were studied. Room temperature fluorescence emission spectra were measured from the same epicotyl spots before and after irradiation with various wavelengths between 280 and 360 nm for 15 min and the "illuminated" minus "dark" difference spectra were calculated. Both the UV-A and the UV-B irradiations caused photoreduction of protochlorophyllide into chlorophyllide. At 10 µmol photons m-2 s-1, the photoreduction rates were similar, however, at 60 µmol photons m-2 s-1, the UV-B irradiation was more effective in inducing chlorophyllide formation than the UV-A. The action spectra of protochlorophyllide plus protochlorophyll loss and chlorophyllide production showed that the radiation around 290 nm was the most effective in provoking protochlorophyllide photoreduction and the UV light above 320 nm caused strong bleaching. These results show that the effect of the UV radiation should be considered when discussing the protochlorophyllide-chlorophyllide photoreduction during germination and as a part of the regeneration of the photosynthetic apparatus proceeding in the daily run of photosynthesis.
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Affiliation(s)
- Anna Laura Erdei
- Department of Plant Anatomy, Faculty of Science, Institute of Biology, ELTE Eötvös Loránd University, Pázmány P. s. 1/c, Budapest, 1117, Hungary
- Department of Zoology, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - Annamária Kósa
- Department of Plant Anatomy, Faculty of Science, Institute of Biology, ELTE Eötvös Loránd University, Pázmány P. s. 1/c, Budapest, 1117, Hungary
| | - Béla Böddi
- Department of Plant Anatomy, Faculty of Science, Institute of Biology, ELTE Eötvös Loránd University, Pázmány P. s. 1/c, Budapest, 1117, Hungary.
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COBRAMM 2.0 — A software interface for tailoring molecular electronic structure calculations and running nanoscale (QM/MM) simulations. J Mol Model 2018; 24:271. [DOI: 10.1007/s00894-018-3769-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/27/2018] [Indexed: 01/04/2023]
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Archipowa N, Kutta RJ, Heyes DJ, Scrutton NS. Stepwise Hydride Transfer in a Biological System: Insights into the Reaction Mechanism of the Light-Dependent Protochlorophyllide Oxidoreductase. Angew Chem Int Ed Engl 2018; 57:2682-2686. [PMID: 29363234 PMCID: PMC5861667 DOI: 10.1002/anie.201712729] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/22/2018] [Indexed: 11/24/2022]
Abstract
Hydride transfer plays a crucial role in a wide range of biological systems. However, its mode of action (concerted or stepwise) is still under debate. Light‐dependent NADPH: protochlorophyllide oxidoreductase (POR) catalyzes the stereospecific trans addition of a hydride anion and a proton across the C17−C18 double bond of protochlorophyllide. Time‐resolved absorption and emission spectroscopy were used to investigate the hydride transfer mechanism in POR. Apart from excited states of protochlorophyllide, three discrete intermediates were resolved, consistent with a stepwise mechanism that involves an initial electron transfer from NADPH. A subsequent proton‐coupled electron transfer followed by a proton transfer yield distinct different intermediates for wild type and the C226S variant, that is, initial hydride attaches to either C17 or C18, but ends in the same chlorophyllide stereoisomer. This work provides the first evidence of a stepwise hydride transfer in a biological system.
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Affiliation(s)
- Nataliya Archipowa
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Roger J Kutta
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.,Current address: Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Derren J Heyes
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
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