1
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Sension RJ, McClain TP, Michocki LB, Miller NA, Alonso-Mori R, Lima FA, Ardana-Lamas F, Biednov M, Chung T, Deb A, Jiang Y, Kaneshiro AK, Khakhulin D, Kubarych KJ, Lamb RM, Meadows JH, Otte F, Sofferman DL, Song S, Uemura Y, van Driel TB, Penner-Hahn JE. Structural Evolution of Photoexcited Methylcobalamin toward a CarH-like Metastable State: Evidence from Time-Resolved X-ray Absorption and X-ray Emission. J Phys Chem B 2024; 128:8131-8144. [PMID: 39150518 DOI: 10.1021/acs.jpcb.4c03729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
CarH is a protein photoreceptor that uses a form of B12, adenosylcobalamin (AdoCbl), to sense light via formation of a metastable excited state. Aside from AdoCbl bound to CarH, methylcobalamin (MeCbl) is the only other example─to date─of photoexcited cobalamins forming metastable excited states with lifetimes of nanoseconds or longer. The UV-visible spectra of the excited states of MeCbl and AdoCbl bound to CarH are similar. We have used transient Co K-edge X-ray absorption and X-ray emission spectroscopies in conjunction with transient absorption spectroscopy in the UV-visible region to characterize the excited states of MeCbl. These data show that the metastable excited state of MeCbl has a slightly expanded corrin ring and increased electron density on the cobalt, but only small changes in the axial bond lengths.
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Affiliation(s)
- Roseanne J Sension
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, United States
| | - Taylor P McClain
- Biophysics, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Lindsay B Michocki
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Nicholas A Miller
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Frederico Alves Lima
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Fernando Ardana-Lamas
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Mykola Biednov
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Taewon Chung
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Aniruddha Deb
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Yifeng Jiang
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - April K Kaneshiro
- Department of Biological Chemistry, 1150 W. Medical Center Dr., Ann Arbor, Michigan 48109-0600, United States
| | - Dmitry Khakhulin
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Kevin J Kubarych
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Ryan M Lamb
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Joseph H Meadows
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Florian Otte
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Danielle L Sofferman
- Program in Applied Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, United States
| | - Sanghoon Song
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Yohei Uemura
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Tim B van Driel
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - James E Penner-Hahn
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
- Biophysics, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
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2
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Pérez-Castaño R, Aranda J, Widner FJ, Kieninger C, Deery E, Warren MJ, Orozco M, Elías-Arnanz M, Padmanabhan S, Kräutler B. The Rhodium Analogue of Coenzyme B 12 as an Anti-Photoregulatory Ligand Inhibiting Bacterial CarH Photoreceptors. Angew Chem Int Ed Engl 2024; 63:e202401626. [PMID: 38416546 DOI: 10.1002/anie.202401626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 02/23/2024] [Accepted: 02/23/2024] [Indexed: 02/29/2024]
Abstract
Coenzyme B12 (AdoCbl; 5'-deoxy-5'-adenosylcobalamin), the quintessential biological organometallic radical catalyst, has a formerly unanticipated, yet extensive, role in photoregulation in bacteria. The light-responsive cobalt-corrin AdoCbl performs this nonenzymatic role by facilitating the assembly of CarH photoreceptors into DNA-binding tetramers in the dark, suppressing gene expression. Conversely, exposure to light triggers the decomposition of this AdoCbl-bound complex by a still elusive photochemical mechanism, activating gene expression. Here, we have examined AdoRhbl, the non-natural rhodium analogue of AdoCbl, as a photostable isostructural surrogate for AdoCbl. We show that AdoRhbl closely emulates AdoCbl in its uptake by bacterial cells and structural functionality as a regulatory ligand for CarH tetramerization, DNA binding, and repressor activity. Remarkably, we find AdoRhbl is photostable even when bound "base-off/His-on" to CarH in vitro and in vivo. Thus, AdoRhbl, an antivitamin B12, also represents an unprecedented anti-photoregulatory ligand, opening a pathway to precisely target biomimetic inhibition of AdoCbl-based photoregulation, with new possibilities for selective antibacterial applications. Computational biomolecular analysis of AdoRhbl binding to CarH yields detailed structural insights into this complex, which suggest that the adenosyl group of photoexcited AdoCbl bound to CarH may specifically undergo a concerted non-radical syn-1,2-elimination mechanism, an aspect not previously considered for this photoreceptor.
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Affiliation(s)
- Ricardo Pérez-Castaño
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - Juan Aranda
- Institute for Research in Biomedicine, IRB Barcelona), Baldiri Reixac 10-12, 08028, Barcelona, Spain
| | - Florian J Widner
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria
| | - Christoph Kieninger
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria
| | - Evelyne Deery
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK
| | - Martin J Warren
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK
- Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, UK
| | - Modesto Orozco
- Institute for Research in Biomedicine, IRB Barcelona), Baldiri Reixac 10-12, 08028, Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona (Spain); the Joint BSC-IRB Research Program in Computational Biology, and Department of Biochemistry and Biomedicine, University of Barcelona, Baldiri Reixac 10-12, 08028, Barcelona, Spain
| | - Montserrat Elías-Arnanz
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - S Padmanabhan
- Instituto de Química Física Blas Cabrera (IQF-CSIC), Consejo Superior de Investigaciones Científicas (CSIC), 119 c/Serrano, 28006, Madrid, Spain
| | - Bernhard Kräutler
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria
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3
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Chung T, McClain TP, Alonso-Mori R, Chollet M, Deb A, Garcia-Esparza AT, Huang Ze En J, Lamb RM, Michocki LB, Reinhard M, van Driel TB, Penner-Hahn JE, Sension RJ. Ultrafast X-ray Absorption Spectroscopy Reveals Excited-State Dynamics of B 12 Coenzymes Controlled by the Axial Base. J Phys Chem B 2024; 128:1428-1437. [PMID: 38301132 DOI: 10.1021/acs.jpcb.3c07779] [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] [Indexed: 02/03/2024]
Abstract
Polarized time-resolved X-ray absorption spectroscopy at the Co K-edge is used to probe the excited-state dynamics and photolysis of base-off methylcobalamin and the excited-state structure of base-off adenosylcobalamin. For both molecules, the final excited-state minimum shows evidence for an expansion of the cavity around the Co ion by ca. 0.04 to 0.05 Å. The 5-coordinate base-off cob(II)alamin that is formed following photodissociation has a structure similar to that of the 5-coordinate base-on cob(II)alamin, with a ring expansion of 0.03 to 0.04 Å and a contraction of the lower axial bond length relative to that in the 6-coordinate ground state. These data provide insights into the role of the lower axial ligand in modulating the reactivity of B12 coenzymes.
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Affiliation(s)
- Taewon Chung
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 481091055, United States
| | - Taylor P McClain
- Biophysics, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Matthieu Chollet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Aniruddha Deb
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 481091055, United States
| | - Angel T Garcia-Esparza
- Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025-7015, United States
| | - Joel Huang Ze En
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 481091055, United States
| | - Ryan M Lamb
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 481091055, United States
| | - Lindsay B Michocki
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 481091055, United States
| | - Marco Reinhard
- Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025-7015, United States
| | - Tim B van Driel
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - James E Penner-Hahn
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 481091055, United States
- Biophysics, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Roseanne J Sension
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 481091055, United States
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, United States
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4
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Li J, Kumar A, Lewis JC. Non-native Intramolecular Radical Cyclization Catalyzed by a B 12 -Dependent Enzyme. Angew Chem Int Ed Engl 2023; 62:e202312893. [PMID: 37874184 PMCID: PMC11328698 DOI: 10.1002/anie.202312893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/12/2023] [Accepted: 10/23/2023] [Indexed: 10/25/2023]
Abstract
Despite the unique reactivity of vitamin B12 and its derivatives, B12 -dependent enzymes remain underutilized in biocatalysis. In this study, we repurposed the B12 -dependent transcription factor CarH to enable non-native radical cyclization reactions. An engineered variant of this enzyme, CarH*, catalyzes the formation γ- and δ-lactams through either redox-neutral or reductive ring closure with marked enhancement of reactivity and selectivity relative to the free B12 cofactor. CarH* also catalyzes an unusual spirocyclization by dearomatization of pendant arenes to produce bicyclic 1,3-diene products instead of 1,4-dienes provided by existing methods. These results and associated mechanistic studies highlight the importance of protein scaffolds for controlling the reactivity of B12 and expanding the synthetic utility of B12 -dependent enzymes.
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Affiliation(s)
- Jianbin Li
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Amardeep Kumar
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Jared C Lewis
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
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5
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Camacho IS, Wall E, Sazanovich IV, Gozzard E, Towrie M, Hunt NT, Hay S, Jones AR. Tuning of B 12 photochemistry in the CarH photoreceptor to avoid radical photoproducts. Chem Commun (Camb) 2023; 59:13014-13017. [PMID: 37831010 DOI: 10.1039/d3cc03900e] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Time-resolved infrared spectroscopy reveals the flow of electron density through coenzyme B12 in the light-activated, bacterial transcriptional regulator, CarH. The protein stabilises a series of charge transfer states that result in a photoresponse that avoids reactive, and potentially damaging, radical photoproducts.
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Affiliation(s)
- Ines S Camacho
- Biometrology, Chemical and Biological Sciences Department, National Physical Laboratory, Teddington, Middlesex, UK.
| | - Emma Wall
- Manchester Institute of Biotechnology and Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester, UK
| | - Igor V Sazanovich
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, UK
| | - Emma Gozzard
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, UK
| | - Mike Towrie
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, UK
| | - Neil T Hunt
- Department of Chemistry and York Biomedical Research Institute, University of York, UK
| | - Sam Hay
- Manchester Institute of Biotechnology and Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester, UK
| | - Alex R Jones
- Biometrology, Chemical and Biological Sciences Department, National Physical Laboratory, Teddington, Middlesex, UK.
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6
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Harmand M, Cammarata M, Chollet M, Krygier AG, Lemke HT, Zhu D. Single-shot X-ray absorption spectroscopy at X-ray free electron lasers. Sci Rep 2023; 13:18203. [PMID: 37875533 PMCID: PMC10598033 DOI: 10.1038/s41598-023-44196-2] [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: 12/12/2022] [Accepted: 10/04/2023] [Indexed: 10/26/2023] Open
Abstract
X-ray Absorption Spectroscopy (XAS) is a widely used X-ray diagnostic method for studying electronic and structural properties of matter. At first glance, the relatively narrow bandwidth and the highly fluctuating spectral structure of X-ray Free Electron Lasers (XFEL) sources seem to require accumulation over many shots to achieve high data quality. To date the best approach to implementing XAS at XFEL facilities has been using monochromators to scan the photon energy across the desired spectral range. While this is possible for easily reproducible samples such as liquids, it is incompatible with many important systems. Here, we demonstrate collection of single-shot XAS spectra over 10s of eV using an XFEL source, with error bars of only a few percent. We additionally show how to extend this technique over wider spectral ranges towards Extended X-ray Absorption Fine Structure measurements, by concatenating a few tens of single-shot measurements. Our results pave the way for future XAS studies at XFELs, in particular those in the femtosecond regime. This advance is envisioned to be especially important for many transient processes that can only be initiated at lower repetition rates, for difficult to reproduce excitation conditions, or for rare samples, such as those encountered in high-energy density physics.
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Affiliation(s)
- Marion Harmand
- IMPMC, Sorbonne Université, UMR CNRS 7590, MNHN, 75005, Paris, France.
| | - Marco Cammarata
- Institut de Physique de Rennes, UMR UR1-CNRS 6251, Université de Rennes 1, 35042, Rennes, France
- European Synchrotron Radiation Facility, Grenoble, France
| | - Matthieu Chollet
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Andrew G Krygier
- IMPMC, Sorbonne Université, UMR CNRS 7590, MNHN, 75005, Paris, France
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | - Henrik T Lemke
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- SwissFEL, Paul Scherrer Institut, Villigen, 5232, Switzerland
| | - Diling Zhu
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
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7
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Poddar H, Rios-Santacruz R, Heyes DJ, Shanmugam M, Brookfield A, Johannissen LO, Levy CW, Jeffreys LN, Zhang S, Sakuma M, Colletier JP, Hay S, Schirò G, Weik M, Scrutton NS, Leys D. Redox driven B 12-ligand switch drives CarH photoresponse. Nat Commun 2023; 14:5082. [PMID: 37604813 PMCID: PMC10442372 DOI: 10.1038/s41467-023-40817-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 08/09/2023] [Indexed: 08/23/2023] Open
Abstract
CarH is a coenzyme B12-dependent photoreceptor involved in regulating carotenoid biosynthesis. How light-triggered cleavage of the B12 Co-C bond culminates in CarH tetramer dissociation to initiate transcription remains unclear. Here, a series of crystal structures of the CarH B12-binding domain after illumination suggest formation of unforeseen intermediate states prior to tetramer dissociation. Unexpectedly, in the absence of oxygen, Co-C bond cleavage is followed by reorientation of the corrin ring and a switch from a lower to upper histidine-Co ligation, corresponding to a pentacoordinate state. Under aerobic conditions, rapid flash-cooling of crystals prior to deterioration upon illumination confirm a similar B12-ligand switch occurs. Removal of the upper His-ligating residue prevents monomer formation upon illumination. Combined with detailed solution spectroscopy and computational studies, these data demonstrate the CarH photoresponse integrates B12 photo- and redox-chemistry to drive large-scale conformational changes through stepwise Co-ligation changes.
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Affiliation(s)
- Harshwardhan Poddar
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK
| | - Ronald Rios-Santacruz
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38044, Grenoble, France
| | - Derren J Heyes
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK
| | - Muralidharan Shanmugam
- Photon Science Institute, Department of Chemistry, University of Manchester, Manchester, UK
| | - Adam Brookfield
- Photon Science Institute, Department of Chemistry, University of Manchester, Manchester, UK
| | - Linus O Johannissen
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK
| | - Colin W Levy
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK
| | - Laura N Jeffreys
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK
| | - Shaowei Zhang
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK
| | - Michiyo Sakuma
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK
| | | | - Sam Hay
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK
| | - Giorgio Schirò
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38044, Grenoble, France
| | - Martin Weik
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38044, Grenoble, France
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK.
| | - David Leys
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, UK.
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8
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Leferman CE, Stoica L, Tiglis M, Stoica BA, Hancianu M, Ciubotaru AD, Salaru DL, Badescu AC, Bogdanici CM, Ciureanu IA, Ghiciuc CM. Overcoming Drug Resistance in a Clinical C. albicans Strain Using Photoactivated Curcumin as an Adjuvant. Antibiotics (Basel) 2023; 12:1230. [PMID: 37627652 PMCID: PMC10451318 DOI: 10.3390/antibiotics12081230] [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: 07/09/2023] [Revised: 07/23/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
The limited antifungal drugs available and the rise of multidrug-resistant Candida species have made the efforts to improve antifungal therapies paramount. To this end, our research focused on the effect of a combined treatment between chemical and photodynamic therapy (PDT) towards a fluconazole-resistant clinical Candida albicans strain. The co-treatment of PDT and curcumin in various doses with fluconazole (FLC) had an inhibitory effect on the growth of the FLC-resistant hospital strain of C. albicans in both difusimetric and broth microdilution methods. The proliferation of the cells was inhibited in the presence of curcumin at 3.125 µM and FLC at 41 µM concentrations. The possible involvement of oxidative stress was analyzed by adding menadione and glutathione as a prooxidant and antioxidant, respectively. In addition, we examined the photoactivated curcumin effect on efflux pumps, a mechanism often linked to drug resistance. Nile Red accumulation assays were used to evaluate efflux pumps activity through fluorescence microscopy and spectrofluorometry. The results showed that photoactivated curcumin at 3.125 µM inhibited the transport of the fluorescent substrate that cells usually expel, indicating its potential in combating drug resistance. Overall, the findings suggest that curcumin, particularly when combined with PDT, can effectively inhibit the growth of FLC-resistant C. albicans, addressing the challenge of yeast resistance to azole antifungals through upregulating multidrug transporters.
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Affiliation(s)
- Carmen-Ecaterina Leferman
- Department of Pharmacology, Medical Specialties II, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (C.-E.L.)
- Department of Ophthalmology, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Laura Stoica
- Department of Cell and Molecular Biology, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Mirela Tiglis
- Department of Anesthesia and Intensive Care, Emergency Clinical Hospital of Bucharest, 014461 Bucharest, Romania
| | - Bogdan Alexandru Stoica
- Department of Biochemistry, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Monica Hancianu
- Department of Pharmacognosy, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Alin Dumitru Ciubotaru
- Department of Pharmacology, Medical Specialties II, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (C.-E.L.)
- Department of Biochemistry, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
- Department of Neurology, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | | | - Aida Corina Badescu
- Department of Microbiology (Bacteriology, Virology) and Parasitology, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | | | - Ioan-Adrian Ciureanu
- Department of Medical Informatics and Biostatistics, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Cristina-Mihaela Ghiciuc
- Department of Pharmacology, Medical Specialties II, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (C.-E.L.)
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9
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Mackintosh MJ, Lodowski P, Kozlowski PM. Photoproduct formation in coenzyme B 12-dependent CarH photoreceptor via a triplet pathway. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 245:112751. [PMID: 37441852 DOI: 10.1016/j.jphotobiol.2023.112751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/14/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023]
Abstract
CarH is a cobalamin-based photoreceptor which has attracted significant interest due to its complex mechanism involving its organometallic coenzyme-B12 chromophore. While several experimental and computational studies have sought to understand CarH's mechanism of action, there are still many aspects of the mechanism which remain unclear. While light is needed to activate the Co-C5' bond, it is not entirely clear whether reaction pathway involves singlet or triplet diradical states. A recent experimental study implicated triplet pathway and importance of intersystem crossing (ISC) as a viable mechanistic route for photoproduct formation in CarH. Herein, a combined quantum mechanics/molecular mechanics approach (QM/MM) was used to explore the involvement of triplet states in CarH. Two possibilities were explored. The first possibility involved photo-induced homolytic cleavage of the Co-C5' where the radical pair (RP) would deactivate to a triplet state (T0) on the ground state potential energy surface (PES). However, a pathway for the formation of the photoproduct, 4',5'-anhydroadenosine (anhAdo), on the triplet ground state PES was not energetically feasible. The second possibility involved exploring a manifold of low-lying triplet excited states computed using TD-DFT within the QM/MM framework. Viable crossings of triplet excited states with singlet excited states were identified using semiclassical Landau-Zener theory and the effectiveness of spin-orbit coupling by El-Sayed rules. Several candidates along both the Co-NIm potential energy curve (PEC) and Co-C5'/Co-NIm PES were identified, which appear to corroborate experimental findings and implicate the possible role of triplet states in CarH.
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Affiliation(s)
- Megan J Mackintosh
- Department of Chemistry, University of Louisville, Louisville, KY 40292, United States
| | - Piotr Lodowski
- Institute of Chemistry, Faculty of Science and Technology, University of Silesia in Katowice, Szkolna 9, PL-40 006 Katowice, Poland
| | - Pawel M Kozlowski
- Department of Chemistry, University of Louisville, Louisville, KY 40292, United States.
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10
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Sension RJ, McClain TP, Lamb RM, Alonso-Mori R, Lima FA, Ardana-Lamas F, Biednov M, Chollet M, Chung T, Deb A, Dewan PA, Gee LB, Huang Ze En J, Jiang Y, Khakhulin D, Li J, Michocki LB, Miller NA, Otte F, Uemura Y, van Driel TB, Penner-Hahn JE. Watching Excited State Dynamics with Optical and X-ray Probes: The Excited State Dynamics of Aquocobalamin and Hydroxocobalamin. J Am Chem Soc 2023. [PMID: 37327324 DOI: 10.1021/jacs.3c04099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Femtosecond time-resolved X-ray absorption (XANES) at the Co K-edge, X-ray emission (XES) in the Co Kβ and valence-to-core regions, and broadband UV-vis transient absorption are combined to probe the femtosecond to picosecond sequential atomic and electronic dynamics following photoexcitation of two vitamin B12 compounds, hydroxocobalamin and aquocobalamin. Polarized XANES difference spectra allow identification of sequential structural evolution involving first the equatorial and then the axial ligands, with the latter showing rapid coherent bond elongation to the outer turning point of the excited state potential followed by recoil to a relaxed excited state structure. Time-resolved XES, especially in the valence-to-core region, along with polarized optical transient absorption suggests that the recoil results in the formation of a metal-centered excited state with a lifetime of 2-5 ps. This combination of methods provides a uniquely powerful tool to probe the electronic and structural dynamics of photoactive transition-metal complexes and will be applicable to a wide variety of systems.
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Affiliation(s)
- Roseanne J Sension
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, United States
| | - Taylor P McClain
- Department of Biophysics, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Ryan M Lamb
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Frederico Alves Lima
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Fernando Ardana-Lamas
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Mykola Biednov
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Matthieu Chollet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Taewon Chung
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Aniruddha Deb
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
- Department of Biophysics, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Paul A Dewan
- Department of Biophysics, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Leland B Gee
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Joel Huang Ze En
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Yifeng Jiang
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Dmitry Khakhulin
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Jianhao Li
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Lindsay B Michocki
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Nicholas A Miller
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Florian Otte
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Yohei Uemura
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Tim B van Driel
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - James E Penner-Hahn
- Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
- Department of Biophysics, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
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11
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Toda MJ, Lodowski P, Mamun AA, Kozlowski PM. Photoproduct formation in coenzyme B 12-dependent CarH via a singlet pathway. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 232:112471. [PMID: 35644067 DOI: 10.1016/j.jphotobiol.2022.112471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/26/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
The CarH photoreceptor exploits of the light-sensing ability of coenzyme B12 ( adenosylcobalamin = AdoCbl) to perform its catalytic function, which includes large-scale structural changes to regulate transcription. In daylight, transcription is activated in CarH via the photo-cleavage of the Co-C5' bond of coenzyme B12. Subsequently, the photoproduct, 4',5'-anhydroadenosine (anhAdo) is formed inducing dissociation of the CarH tetramer from DNA. Several experimental studies have proposed that hydridocoblamin (HCbl) may be formed in process with anhAdo. The photolytic cleavage of the Co-C5' bond of AdoCbl was previously investigated using photochemical techniques and the involvement of both singlet and triplet excited states were explored. Herein, QM/MM calculations were employed to probe (1) the photolytic processes which may involve singlet excited states, (2) the mechanism of anhAdo formation, and (3) whether HCbl is a viable intermediate in CarH. Time-dependent density functional theory (TD-DFT) calculations indicate that the mechanism of photodissociation of the Ado ligand involves the ligand field (LF) portion of the lowest singlet excited state (S1) potential energy surface (PES). This is followed by deactivation to a point on the S0 PES where the Co-C5' bond remains broken. This species corresponds to a singlet diradical intermediate. From this point, the PES for anhAdo formation was explored, using the Co-C5' and Co-C4' bond distances as active coordinates, and a local minimum representing anhAdo and HCbl formation was found. The transition state (TS) for the formation of the Co-H bond of HCbl was located and its identity was confirmed by a single imaginary frequency of i1592 cm-1. Comparisons to experimental studies and the potential role of rotation around the N-glycosidic bond of the Ado ligand were discussed.
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Affiliation(s)
- Megan J Toda
- Department of Chemistry, University of Louisville, Louisville, KY 40292, United States
| | - Piotr Lodowski
- Institute of Chemistry, Faculty of Science and Technology, University of Silesia in Katowice, Szkolna 9, PL-40 006 Katowice, Poland
| | - Abdullah Al Mamun
- Department of Chemistry, University of Louisville, Louisville, KY 40292, United States
| | - Pawel M Kozlowski
- Department of Chemistry, University of Louisville, Louisville, KY 40292, United States.
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12
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Poddar H, Heyes DJ, Zhang S, Hardman SJ, Sakuma M, Scrutton NS. An unusual light-sensing function for coenzyme B 12 in bacterial transcription regulator CarH. Methods Enzymol 2022; 668:349-372. [PMID: 35589201 DOI: 10.1016/bs.mie.2021.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Coenzyme B12 is one of the most complex cofactors found in nature and synthesized de novo by certain groups of bacteria. Although its use in various enzymatic reactions is well characterized, only recently an unusual light-sensing function has been ascribed to coenzyme B12. It has been reported that the coenzyme B12 binding protein CarH, found in the carotenoid biosynthesis pathway of several thermostable bacteria, binds to the promoter region of DNA and suppresses transcription. To overcome the harmful effects of light-induced damage in the cells, CarH releases DNA in the presence of light and promotes transcription and synthesis of carotenoids, thereby working as a photoreceptor. CarH is able to achieve this by exploiting the photosensitive nature of the CoC bond between the adenosyl moiety and the cobalt atom in the coenzyme B12 molecule. Extensive structural and spectroscopy studies provided a mechanistic understanding of the molecular basis of this unique light-sensitive reaction. Most studies on CarH have used the ortholog from the thermostable bacterium Thermus thermophilus, due to the ease with which it can be expressed and purified in high quantities. In this chapter we give an overview of this intriguing class of photoreceptors and report a step-by-step protocol for expression, purification and spectroscopy experiments (both static and time-resolved techniques) employed in our laboratory to study CarH from T. thermophilus. We hope the contents of this chapter will be of interest to the wider coenzyme B12 community and apprise them of the potential and possibilities of using coenzyme B12 as a light-sensing probe in a protein scaffold.
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Affiliation(s)
- Harshwardhan Poddar
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, United Kingdom
| | - Derren J Heyes
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, United Kingdom
| | - Shaowei Zhang
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, United Kingdom
| | - Samantha J Hardman
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, United Kingdom
| | - Michiyo Sakuma
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, United Kingdom
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, Manchester, United Kingdom.
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13
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Padmanabhan S, Pérez-Castaño R, Osete-Alcaraz L, Polanco MC, Elías-Arnanz M. Vitamin B 12 photoreceptors. VITAMINS AND HORMONES 2022; 119:149-184. [PMID: 35337618 DOI: 10.1016/bs.vh.2022.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Photoreceptor proteins enable living organisms to sense light and transduce this signal into biochemical outputs to elicit appropriate cellular responses. Their light sensing is typically mediated by covalently or noncovalently bound molecules called chromophores, which absorb light of specific wavelengths and modulate protein structure and biological activity. Known photoreceptors have been classified into about ten families based on the chromophore and its associated photosensory domain in the protein. One widespread photoreceptor family uses coenzyme B12 or 5'-deoxyadenosylcobalamin, a biological form of vitamin B12, to sense ultraviolet, blue, or green light, and its discovery revealed both a new type of photoreceptor and a novel functional facet of this vitamin, best known as an enzyme cofactor. Large strides have been made in our understanding of how these B12-based photoreceptors function, high-resolution structural descriptions of their functional states are available, as are details of their unusual photochemistry. Additionally, they have inspired notable applications in optogenetics/optobiochemistry and synthetic biology. Here, we provide an overview of what is currently known about these B12-based photoreceptors, their discovery, distribution, molecular mechanism of action, and the structural and photochemical basis of how they orchestrate signal transduction and gene regulation, and how they have been used to engineer optogenetic control of protein activities in living cells.
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Affiliation(s)
- S Padmanabhan
- Instituto de Química Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid, Spain.
| | - Ricardo Pérez-Castaño
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Lucía Osete-Alcaraz
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - María Carmen Polanco
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Montserrat Elías-Arnanz
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, Murcia, Spain.
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14
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Welfare JG, Mortelliti MJ, McGlade CA, Hartman TW, Dempsey JL, Lawrence DS. Assessment of Photoreleasable Linkers and Light-Capturing Antennas on a Photoresponsive Cobalamin Scaffold. J Org Chem 2022; 87:5076-5084. [PMID: 35353509 PMCID: PMC9727707 DOI: 10.1021/acs.joc.1c02931] [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
Cobalamin has shown promise as a light-sensitive drug delivery platform owing to its ease of modification and the high quantum yields for drug photorelease. However, studies to date on the general photochemistry of alkyl cobalamins have primarily focused on methyl and adenosyl-substituted derivatives, the natural cofactors present in various enzymatic species. We describe the synthesis and photolytic behavior of cobalamin conjugates comprised of different combinations of fluorophores and β-axial ligands. In general, cobalamin conjugates containing β-axial alkyl substituents undergo efficient photolysis under aqueous conditions, with quantum yields up to >40%. However, substituents that are large and hydrophobic, or unable to readily support the presumed radical intermediate, suffer less efficient photolysis (<15%) than smaller, water-soluble, analogs. By contrast, quantum yields improve by 2-fold in DMF for cobalamins containing large hydrophobic β-axial substituents. This suggests that drug release from carriers comprised of membranous compartments, such as liposomes, may be significantly more efficient than the corresponding photorelease in an aqueous environment. Finally, we explored the impact of fluorophores on the photolysis of alkyl cobalamins under tissue-mimetic conditions. Cobalamins substituted with efficient photon-capturing fluorophores display up to 4-fold enhancements in photolysis relative to unsubstituted derivatives. In summary, we have shown that the photosensitivity of alkyl cobalamin conjugates can be tuned by altering the Co-appended alkyl moiety, modulating the polarity of the environment (solvent), and installing photon-capturing fluorophores onto the cobalamin framework.
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15
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Ghosh AP, Lodowski P, Kozlowski PM. Aerobic photolysis of methylcobalamin: unraveling the photoreaction mechanism. Phys Chem Chem Phys 2022; 24:6093-6106. [PMID: 35212341 DOI: 10.1039/d1cp02013g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photo-reactivity of cobalamins (Cbls) is influenced by the nature of axial ligands and the cofactor's environment. While the biologically active forms of Cbls with alkyl axial ligands, such as methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl), are considered to be photolytically active, in contrast, the non-alkyl Cbls are photostable. In addition to these, the photolytic properties of Cbls can also be modulated in the presence of molecular oxygen, i.e., under aerobic conditions. Herein, the photoreaction of the MeCbl in the presence of oxygen has been explored using density functional theory (DFT) and time-dependent DFT (TD-DFT). The first stage of the aerobic photoreaction is the activation of the Co-C bond and the formation of the ligand field (LF) electronic state through the displacement of axial bonds. Once the photoreaction reaches the LF excited state, three processes can occur: namely the formation of OO-CH3 through the reaction of CH3 with molecular oxygen, de-activation of the {Im⋯[CoII(corrin)]⋯CH3}+ sub-system from the LF electronic state by changing the electronic configuration from (dyz)1(dz2)2 to (dyz)2(dz2)1 and the formation of the deactivation complex (DC) complex via the recombination of OO-CH3 species with the de-excited [CoII(corrin)] system. In the proposed mechanism, the deactivation of the [CoII(corrin)] subsystem may coexist with the formation of OO-CH3, followed by immediate relaxation of the subsystems in the ground state. Moreover, the formation of the OO-CH3 species followed by the formation of the {[CoIII(corrin)]-OO-CH3}+ complex stabilizes the system compared to the reactant complex.
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Affiliation(s)
- Arghya Pratim Ghosh
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, USA.
| | - Piotr Lodowski
- Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, PL-40 006 Katowice, Poland
| | - Pawel M Kozlowski
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, USA.
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16
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Ghosh AP, Toda MJ, Kozlowski PM. Photolytic properties of B 12-dependent enzymes: A theoretical perspective. VITAMINS AND HORMONES 2022; 119:185-220. [PMID: 35337619 DOI: 10.1016/bs.vh.2022.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The biologically active vitamin B12 derivates, methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl), are ubiquitous organometallic cofactors. In addition to their key roles in enzymatic catalysis, B12 cofactors have complex photolytic properties which have been the target of experimental and theoretical studies. With the recent discovery of B12-dependent photoreceptors, there is an increased need to elucidate the underlying photochemical mechanisms of these systems. This book chapter summarizes the photolytic properties of MeCbl- and AdoCbl-dependent enzymes with particular emphasis on the effect of the environment of the cofactor on the excited state processes. These systems include isolated MeCbl and AdoCbl as well as the enzymes, ethanolamine ammonia-lyase (EAL), glutamate mutase (GLM), methionine synthase (MetH), and photoreceptor CarH. Central to determining the photodissociation mechanism of each system is the analysis of the lowest singlet excited state (S1) potential energy surface (PES). Time-dependent density functional theory (TD-DFT), employing BP86/TZVPP, is widely used to construct such PESs. Regardless of the environment, the topology of the S1 PES of AdoCbl or MeCbl is marked by characteristic features, namely the metal-to-ligand charge transfer (MLCT) and ligand field (LF) regions. Conversely, the relative energetics of these electronic states are affected by the environment. Applications and outlooks for Cbl photochemistry are also discussed.
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Affiliation(s)
- Arghya Pratim Ghosh
- Department of Chemistry, University of Louisville, Louisville, KY, United States
| | - Megan J Toda
- Department of Chemistry, University of Louisville, Louisville, KY, United States
| | - Pawel M Kozlowski
- Department of Chemistry, University of Louisville, Louisville, KY, United States.
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17
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Yang X, Gerroll BHR, Jiang Y, Kumar A, Zubi YS, Baker LA, Lewis JC. Controlling Non-Native Cobalamin Reactivity and Catalysis in the Transcription Factor CarH. ACS Catal 2022; 12:935-942. [PMID: 35340760 DOI: 10.1021/acscatal.1c04748] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Vitamin B12 derivatives catalyze a wide range of organic transformations, but B12-dependent enzymes are underutilized in biocatalysis relative to other metalloenzymes. In this study, we engineered a variant of the transcription factor CarH, called CarH*, that catalyzes styrene C-H alkylation with improved yields (2-6.5-fold) and selectivity relative to cobalamin. While the native function of CarH involves transcription regulation via adenosylcobalamin (AdoCbl) Co(III)-carbon bond cleavage and β-hydride elimination to generate 4',5'-didehydroadenosine, CarH*-catalyzed styrene alkylation proceeds via non-native oxidative addition and olefin addition coupled with a native-like β-hydride elimination. Mechanistic studies on this reaction echo findings from earlier studies on AdoCbl homolysis to suggest that CarH* selectivity results from its ability to impart a cage effect on radical intermediates. These findings lay the groundwork for the development of B12-dependent enzymes as catalysts for non-native transformations.
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Affiliation(s)
- Xinhang Yang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | | | - Yuhua Jiang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Amardeep Kumar
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Yasmine S. Zubi
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Lane A. Baker
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Jared C. Lewis
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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18
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Pérez-Castaño R, Bastida-Martínez E, Fernández Zapata J, Polanco MDC, Galbis-Martínez ML, Iniesta AA, Fontes M, Padmanabhan S, Elías-Arnanz M. Coenzyme B 12 -dependent and independent photoregulation of carotenogenesis across Myxococcales. Environ Microbiol 2022; 24:1865-1886. [PMID: 35005822 PMCID: PMC9304148 DOI: 10.1111/1462-2920.15895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 12/27/2021] [Accepted: 01/01/2022] [Indexed: 11/28/2022]
Abstract
Light-induced carotenogenesis in Myxococcus xanthus is controlled by the B12 -based CarH repressor and photoreceptor, and by a separate intricate pathway involving singlet oxygen, the B12 -independent CarH paralog CarA and various other proteins, some eukaryotic-like. Whether other myxobacteria conserve these pathways and undergo photoregulated carotenogenesis is unknown. Here, comparative analyses across 27 Myxococcales genomes identified carotenogenic genes, albeit arranged differently, with carH often in their genomic vicinity, in all three Myxococcales suborders. However, CarA and its associated factors were found exclusively in suborder Cystobacterineae, with carA-carH invariably in tandem in a syntenic carotenogenic operon, except for Cystobacter/Melittangium, which lack CarA but retain all other factors. We experimentally show B12 -mediated photoregulated carotenogenesis in representative myxobacteria, and a remarkably plastic CarH operator design and DNA binding across Myxococcales. Unlike the two characterized CarH from other phyla, which are tetrameric, Cystobacter CarH (the first myxobacterial homolog amenable to analysis in vitro) is a dimer that combines direct CarH-like B12 -based photoregulation with CarA-like DNA-binding and inhibition by an antirepressor. This study provides new molecular insights into B12 -dependent photoreceptors. It further establishes the B12 -dependent pathway for photoregulated carotenogenesis as broadly prevalent across myxobacteria and its evolution, exclusively in one suborder, into a parallel complex B12 -independent circuit. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ricardo Pérez-Castaño
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - Eva Bastida-Martínez
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - Jesús Fernández Zapata
- Instituto de Química Física "Rocasolano", Consejo Superior de Investigaciones Científicas, 28006, Madrid, Spain
| | - María Del Carmen Polanco
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - María Luisa Galbis-Martínez
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - Antonio A Iniesta
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - Marta Fontes
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - S Padmanabhan
- Instituto de Química Física "Rocasolano", Consejo Superior de Investigaciones Científicas, 28006, Madrid, Spain
| | - Montserrat Elías-Arnanz
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
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19
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Sension RJ, Chung T, Dewan P, McClain TP, Lamb RM, Penner-Hahn JE. Time-resolved spectroscopy: Advances in understanding the electronic structure and dynamics of cobalamins. Methods Enzymol 2022; 669:303-331. [DOI: 10.1016/bs.mie.2022.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Toda MJ, Lodowski P, Mamun AA, Kozlowski PM. Electronic and photolytic properties of hydridocobalamin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2021; 224:112295. [PMID: 34548209 DOI: 10.1016/j.jphotobiol.2021.112295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/06/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Hydridocobalamin (HCbl), is a known member of the B12 family of molecules (cobalamins, Cbls) yet unlike other well-studied Cbls, little is known of the electronic and photolytic properties of this species. Interest in HCbl has increased significantly in recent years when at least three experimentally proposed mechanisms implicate HCbl as an intermediary in the photoreaction of coenzyme B12-dependent photoreceptor CarH. Specifically, cleavage of the Co-C5' bond of coenzyme B12 could lead to a β-hydride or β‑hydrogen elimination reaction to form HCbl. HCbl is known to be a transient species where the oxidation state of the Co is variable; Co(I)-H+ ↔ Co(II)-H ↔ Co(III)-H-. Further, HCbl is a very unstable with a pKa of ~1. This complicates experimental studies and to the best of our knowledge there are no available crystal structures of HCbl - either for the isolated molecule or bound to an enzyme. In this study, the electronic structure, photolytic properties, and reactivity of HCbl were explored to determine the preferred oxidation state as well as its potential role in the formation of the photoproduct in CarH. Natural bond orbital (NBO) analysis was performed to determine the oxidation state of Co in isolated HCbl. Based on the NBO analysis of HCbl, Co clearly had excess negative charge, which is in stark contrast to other alkylCbls where the Co ion is marked by significant positive charge. In sum, NBO results indicate that the CoH bond is strongly polarized and almost ionic. It can be described as protonated Co(I). In addition, DFT was used to explore the bond dissociation energy of HCbl based on homolytic cleavage of the CoH bond. TD-DFT calculations were used to compare computed electronic transitions to the experimentally determined absorption spectrum. The photoreaction of CarH was explored using an isolated model system and a pathway for hydrogen transfer was found. Finally, quantum mechanics/molecular mechanics (QM/MM) calculations were employed to investigate the formation of HCbl in CarH.
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Affiliation(s)
- Megan J Toda
- Department of Chemistry, University of Louisville, Louisville, KY 40292, United States
| | - Piotr Lodowski
- Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, PL-40 006 Katowice, Poland
| | - Abdullah Al Mamun
- Department of Chemistry, University of Louisville, Louisville, KY 40292, United States
| | - Pawel M Kozlowski
- Department of Chemistry, University of Louisville, Louisville, KY 40292, United States.
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Light-Triggered Carotenogenesis in Myxococcus xanthus: New Paradigms in Photosensory Signaling, Transduction and Gene Regulation. Microorganisms 2021; 9:microorganisms9051067. [PMID: 34063365 PMCID: PMC8156234 DOI: 10.3390/microorganisms9051067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 11/17/2022] Open
Abstract
Myxobacteria are Gram-negative δ-proteobacteria found predominantly in terrestrial habitats and often brightly colored due to the biosynthesis of carotenoids. Carotenoids are lipophilic isoprenoid pigments that protect cells from damage and death by quenching highly reactive and toxic oxidative species, like singlet oxygen, generated upon growth under light. The model myxobacterium Myxococcus xanthus turns from yellow in the dark to red upon exposure to light because of the photoinduction of carotenoid biosynthesis. How light is sensed and transduced to bring about regulated carotenogenesis in order to combat photooxidative stress has been extensively investigated in M. xanthus using genetic, biochemical and high-resolution structural methods. These studies have unearthed new paradigms in bacterial light sensing, signal transduction and gene regulation, and have led to the discovery of prototypical members of widely distributed protein families with novel functions. Major advances have been made over the last decade in elucidating the molecular mechanisms underlying the light-dependent signaling and regulation of the transcriptional response leading to carotenogenesis in M. xanthus. This review aims to provide an up-to-date overview of these findings and their significance.
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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: 29] [Impact Index Per Article: 7.3] [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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