1
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Pushkaran AC, Arabi AA. A review on point mutations via proton transfer in DNA base pairs in the absence and presence of electric fields. Int J Biol Macromol 2024; 277:134051. [PMID: 39069038 DOI: 10.1016/j.ijbiomac.2024.134051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 07/12/2024] [Accepted: 07/18/2024] [Indexed: 07/30/2024]
Abstract
This comprehensive review focuses on spontaneous mutations that may occur during DNA replication, the fundamental process responsible for transferring genetic information. In 1963, Löwdin postulated that these mutations are primarily a result of proton transfer reactions within the hydrogen-bonded DNA base pairs. The single and double proton transfer reactions within the base pairs in DNA result in zwitterions and rare tautomers, respectively. For persistent mutations, these products must be generated at high rates and should be thermodynamically stable. This review covers the proton transfer reactions studied experimentally and computationally. The review also examines the influence of externally applied electric fields on the thermodynamics and kinetics of proton transfer reactions within DNA base pairs, and their biological implications.
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Affiliation(s)
- Anju Choorakottayil Pushkaran
- Department of Biochemistry and Molecular Biology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, P.O. Box: 15551, United Arab Emirates
| | - Alya A Arabi
- Department of Biochemistry and Molecular Biology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, P.O. Box: 15551, United Arab Emirates.
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2
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Li M, Zhang T, Shi Y, He C, Duan C. Modifying Proton Relay into Bioinspired Dye-Based Coordination Polymer for Photocatalytic Proton-Coupled Electron Transfer. Angew Chem Int Ed Engl 2024; 63:e202406161. [PMID: 38864758 DOI: 10.1002/anie.202406161] [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: 03/31/2024] [Revised: 05/23/2024] [Accepted: 06/10/2024] [Indexed: 06/13/2024]
Abstract
Proton-coupled electron transfer (PCET) imparts an energetic advantage over single electron transfer in activating inert substances. Natural PCET enzyme catalysis generally requires tripartite preorganization of proton relay, substrate-bound active center, and redox mediator, making the processes efficient and precluding side reactions. Inspired by this, a heterogeneous photocatalytic PCET system was established to achieve higher PCET driving forces by modifying proton relays into anthraquinone-based anionic coordination polymers. The proximally separated proton relays and photoredox-mediating anthraquinone moiety allowed pre-assembly of inert substrate between them, merging proton and electron into unsaturated bonds by photoreductive PCET, which enhanced reaction kinetics compared with the counter catalyst without proton relay. This photocatalytic PCET method was applied to a broad-scoped reduction of aryl ketones, unsaturated carbonyls, and aromatic compounds. The distinctive regioselectivities for the reduction of isoquinoline derivatives were found to occur on the carbon-ring sides. PCET-generated radical intermediate of quinoline could be trapped by alkene for proton relay-assisted Minisci addition, forming the pharmaceutical aza-acenaphthene scaffold within one step. When using heteroatom(X)-H/C-H compounds as proton-electron donors, this protocol could activate these inert bonds through photooxidative PCET to afford radicals and trap them by electron-deficient unsaturated compounds, furnishing the direct X-H/C-H functionalization.
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Affiliation(s)
- Mochen Li
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, School of Chemistry, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Tiexin Zhang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, School of Chemistry, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Yusheng Shi
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, School of Chemistry, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Cheng He
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, School of Chemistry, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Chunying Duan
- State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210023, P. R. China
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3
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Zhu Q, Soudackov AV, Tommos C, Hammes-Schiffer S. Proton-Coupled Electron Transfer upon Oxidation of Tyrosine in a De Novo Protein: Analysis of Proton Acceptor Candidates. Biochemistry 2024; 63:1999-2008. [PMID: 39024184 DOI: 10.1021/acs.biochem.4c00211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Redox-active residues, such as tyrosine and tryptophan, play important roles in a wide range of biological processes. The α3Y de novo protein, which is composed of three α helices and a tyrosine residue Y32, provides a platform for investigating the redox properties of tyrosine in a well-defined protein environment. Herein, the proton-coupled electron transfer (PCET) reaction that occurs upon oxidation of tyrosine in this model protein by a ruthenium photosensitizer is studied by using a vibronically nonadiabatic PCET theory that includes hydrogen tunneling and excited vibronic states. The input quantities to the analytical nonadiabatic rate constant expression, such as the diabatic proton potential energy curves and associated proton vibrational wave functions, reorganization energy, and proton donor-acceptor distribution functions, are obtained from density functional theory calculations on model systems and molecular dynamics simulations of the solvated α3Y protein. Two possible proton acceptors, namely, water or a glutamate residue in the protein scaffold, are explored. The PCET rate constant is greater when glutamate is the proton acceptor, mainly due to the more favorable driving force and shorter equilibrium proton donor-acceptor distance, although contributions from excited vibronic states mitigate these effects. Nevertheless, water could be the dominant proton acceptor if its equilibrium constant associated with hydrogen bond formation is significantly greater than that for glutamate. Although these calculations do not definitively identify the proton acceptor for this PCET reaction, they elucidate the conditions under which each proton acceptor can be favored. These insights have implications for tyrosine-based PCET in a wide variety of biochemical processes.
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Affiliation(s)
- Qiwen Zhu
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Alexander V Soudackov
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Cecilia Tommos
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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4
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Ji T, Su S, Wu S, Hori Y, Shigeta Y, Huang Y, Zheng W, Xu W, Zhang X, Kiyanagi R, Munakata K, Ohhara T, Nakanishi T, Sato O. Development of an Fe II Complex Exhibiting Intermolecular Proton Shifting Coupled Spin Transition. Angew Chem Int Ed Engl 2024; 63:e202404843. [PMID: 38622084 DOI: 10.1002/anie.202404843] [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: 03/11/2024] [Revised: 04/13/2024] [Accepted: 04/15/2024] [Indexed: 04/17/2024]
Abstract
In this study, we investigated reversible intermolecular proton shifting (IPS) coupled with spin transition (ST) in a novel FeII complex. The host FeII complex and the guest carboxylic acid anion were connected by intermolecular hydrogen bonds (IHBs). We extended the intramolecular proton transfer coupled ST phenomenon to the intermolecular system. The dynamic phenomenon was confirmed by variable-temperature single-crystal X-ray diffraction, neutron crystallography, and infrared spectroscopy. The mechanism of IPS was further validated using density functional theory calculations. The discovery of IPS-coupled ST in crystalline molecular materials provides good insights into fundamental processes and promotes the design of novel multifunctional materials with tunable properties for various applications, such as optoelectronics, information storage, and molecular devices.
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Affiliation(s)
- Tianchi Ji
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Shengqun Su
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Shuqi Wu
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Yuta Hori
- Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Yasuteru Shigeta
- Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Yubo Huang
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Wenwei Zheng
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Wenhuang Xu
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Xiaopeng Zhang
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Ryoji Kiyanagi
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki, 319-1195, Japan
| | - Koji Munakata
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, 162-1 Shirakata, Tokai, Ibaraki, 319-1106, Japan
| | - Takashi Ohhara
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki, 319-1195, Japan
| | - Takumi Nakanishi
- Institute for Materials Research, Tohoku University, 211 Katahira, Aoba Ward, Sendai, Miyagi, 980-8577, Japan
| | - Osamu Sato
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
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5
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Tran DK, West SM, Speck EMK, Jenekhe SA. Observation of super-Nernstian proton-coupled electron transfer and elucidation of nature of charge carriers in a multiredox conjugated polymer. Chem Sci 2024; 15:7623-7642. [PMID: 38784743 PMCID: PMC11110174 DOI: 10.1039/d4sc00785a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 04/16/2024] [Indexed: 05/25/2024] Open
Abstract
Nernstian proton-coupled electron transfer (PCET) is a fundamental process central to many physical and biological systems, such as electrocatalysis, enzyme operation, DNA biosynthesis, pH-/bio-sensors, and electrochemical energy storage devices. We report herein the discovery of super-Nernstian PCET behavior with two protons per electron transferred in the electrochemical doping of a redox conjugated polymer, phenazine-substituted ladder poly(benzimidazobenzophenanthroline) (BBL-P), in aqueous electrolyte. We show that the super-Nernstian response originates from existence of multiredox centers that have a gradient of pKa on the conjugated polymer. Our use of various pH-dependent in operando techniques to probe the nature of charge carriers in n-doped BBL-P found that polarons are the charge carriers at low to intermediate levels of doping (0.1-1.0 electron per repeat unit (eru)) whereas at higher doing levels (1.3 eru), polarons, polaron pairs, and bipolarons co-exist, which evolve into strongly coupled polaron pairs at the highest doping levels (>1.5 eru). We show that PCET-assisted n-doping of BBL-P results in very high redox capacity (>1200 F cm-3) in acidic electrolyte. Our results provide important new insights into PCET in organic materials and the nature of charge carriers in n-doped conjugated polymers while having implications for various electrochemical devices.
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Affiliation(s)
- Duyen K Tran
- Department of Chemical Engineering, University of Washington Seattle Washington 98195-1750 USA
| | - Sarah M West
- Department of Chemistry, University of Washington Seattle Washington 98195-1750 USA
| | - Elizabeth M K Speck
- Department of Chemistry, University of Washington Seattle Washington 98195-1750 USA
| | - Samson A Jenekhe
- Department of Chemical Engineering, University of Washington Seattle Washington 98195-1750 USA
- Department of Chemistry, University of Washington Seattle Washington 98195-1750 USA
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6
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Ayuso-Fernández I, Emrich-Mills TZ, Haak J, Golten O, Hall KR, Schwaiger L, Moe TS, Stepnov AA, Ludwig R, Cutsail Iii GE, Sørlie M, Kjendseth Røhr Å, Eijsink VGH. Mutational dissection of a hole hopping route in a lytic polysaccharide monooxygenase (LPMO). Nat Commun 2024; 15:3975. [PMID: 38729930 PMCID: PMC11087555 DOI: 10.1038/s41467-024-48245-w] [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: 09/18/2023] [Accepted: 04/25/2024] [Indexed: 05/12/2024] Open
Abstract
Oxidoreductases have evolved tyrosine/tryptophan pathways that channel highly oxidizing holes away from the active site to avoid damage. Here we dissect such a pathway in a bacterial LPMO, member of a widespread family of C-H bond activating enzymes with outstanding industrial potential. We show that a strictly conserved tryptophan is critical for radical formation and hole transference and that holes traverse the protein to reach a tyrosine-histidine pair in the protein's surface. Real-time monitoring of radical formation reveals a clear correlation between the efficiency of hole transference and enzyme performance under oxidative stress. Residues involved in this pathway vary considerably between natural LPMOs, which could reflect adaptation to different ecological niches. Importantly, we show that enzyme activity is increased in a variant with slower radical transference, providing experimental evidence for a previously postulated trade-off between activity and redox robustness.
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Affiliation(s)
- Iván Ayuso-Fernández
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway.
| | - Tom Z Emrich-Mills
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Julia Haak
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
- Institute of Inorganic Chemistry, University of Duisburg-Essen, 45141, Essen, Germany
| | - Ole Golten
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Kelsi R Hall
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Lorenz Schwaiger
- Biocatalysis and Biosensing Laboratory, Department of Food Sciences and Technology, Institute of Food Science and Technology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18/2, Vienna, 1190, Austria
| | - Trond S Moe
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Anton A Stepnov
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Roland Ludwig
- Biocatalysis and Biosensing Laboratory, Department of Food Sciences and Technology, Institute of Food Science and Technology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18/2, Vienna, 1190, Austria
| | - George E Cutsail Iii
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
- Institute of Inorganic Chemistry, University of Duisburg-Essen, 45141, Essen, Germany
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Åsmund Kjendseth Røhr
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway.
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7
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Dance I. What triggers the coupling of proton transfer and electron transfer at the active site of nitrogenase? Dalton Trans 2024; 53:7996-8004. [PMID: 38651170 DOI: 10.1039/d4dt00474d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
In converting N2 to NH3 the enzyme nitrogenase utilises 8 electrons and 8 protons in the complete catalytic cycle. The source of the electrons is an Fe4S4 reductase protein (Fe-protein) which temporarily docks with the MoFe-protein that contains the catalytic active cofactor, FeMo-co, and an electron transfer cluster called the P cluster. The overall mechanism involves 8 repetitions of a cycle in which reduced Fe-protein docks with the MoFe-protein, one electron transfers to the P-cluster, and then to FeMo-co, followed by dissociation of the two proteins and re-reduction of the Fe-protein. Protons are supplied serially to FeMo-co by a Grotthuss proton translocation mechanism from the protein surface along a conserved chain of water molecules (a proton wire) that terminates near S atoms of the FeMo-co cluster [CFe7S9Mo(homocitrate)] where the multiple steps of the chemical conversions are effected. It is assumed that the chemical mechanisms use proton-coupled electron-transfer (PCET) and that H atoms (e- + H+) are involved in each of the hydrogenation steps. However there is neither evidence for, or mechanism proposed, for this coupling. Here I report calculations of cluster charge distribution upon electron addition, revealing that the added negative charge is on the S atoms of FeMo-co, which thereby become more basic, and able to trigger proton transfer from H3O+ waiting at the near end of the proton wire. This mechanism is supported by calculations of the dynamics of the proton transfer step, in which the barrier is reduced by ca. 3.5 kcal mol-1 and the product stabilised by ca. 7 kcal mol-1 upon electron addition. H tunneling is probable in this step. In nitrogenase it is electron transfer that triggers proton transfer.
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Affiliation(s)
- Ian Dance
- School of Chemistry, UNSW Sydney, NSW 2052, Australia.
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8
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Nilsen-Moe A, Reinhardt CR, Huang P, Agarwala H, Lopes R, Lasagna M, Glover S, Hammes-Schiffer S, Tommos C, Hammarström L. Switching the proton-coupled electron transfer mechanism for non-canonical tyrosine residues in a de novo protein. Chem Sci 2024; 15:3957-3970. [PMID: 38487244 PMCID: PMC10935721 DOI: 10.1039/d3sc05450k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/23/2024] [Indexed: 03/17/2024] Open
Abstract
The proton-coupled electron transfer (PCET) reactions of tyrosine (Y) are instrumental to many redox reactions in nature. This study investigates how the local environment and the thermodynamic properties of Y influence its PCET characteristics. Herein, 2- and 4-mercaptophenol (MP) are placed in the well-folded α3C protein (forming 2MP-α3C and 4MP-α3C) and oxidized by external light-generated [Ru(L)3]3+ complexes. The resulting neutral radicals are long-lived (>100 s) with distinct optical and EPR spectra. Calculated spin-density distributions are similar to canonical Y˙ and display very little spin on the S-S bridge that ligates the MPs to C32 inside the protein. With 2MP-α3C and 4MP-α3C we probe how proton transfer (PT) affects the PCET rate constants and mechanisms by varying the degree of solvent exposure or the potential to form an internal hydrogen bond. Solution NMR ensemble structures confirmed our intended design by displaying a major difference in the phenol OH solvent accessible surface area (≤∼2% for 2MP and 30-40% for 4MP). Additionally, 2MP-C32 is within hydrogen bonding distance to a nearby glutamate (average O-O distance is 3.2 ± 0.5 Å), which is suggested also by quantum mechanical/molecular mechanical (QM/MM) molecular dynamics simulations. Neither increased exposure of the phenol OH to solvent (buffered water), nor the internal hydrogen bond, was found to significantly affect the PCET rates. However, the lower phenol pKa values associated with the MP-α3C proteins compared to α3Y provided a sufficient change in PT driving force to alter the PCET mechanism. The PCET mechanism for 2MP-α3C and 4MP-α3C with moderately strong oxidants was predominantly step-wise PTET for pH values, but changed to concerted PCET at neutral pH values and below when a stronger oxidant was used, as found previously for α3Y. This shows how the balance of ET and PT driving forces is critical for controlling PCET mechanisms. The presented results improve our general understanding of amino-acid based PCET in enzymes.
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Affiliation(s)
- Astrid Nilsen-Moe
- Department of Chemistry, Ångström Laboratory, Uppsala University Box 523 75120 Uppsala Sweden
| | - Clorice R Reinhardt
- Department of Molecular Biophysics and Biochemistry, Yale University New Haven CT 06520 USA
| | - Ping Huang
- Department of Chemistry, Ångström Laboratory, Uppsala University Box 523 75120 Uppsala Sweden
| | - Hemlata Agarwala
- Technical University Munich, Campus Straubing for Biotechnology and Sustainability Uferstraße 53 94315 Straubing Germany
| | - Rosana Lopes
- Department of Biochemistry and Biophysics, Texas A&M University College Station TX 77843 USA
| | - Mauricio Lasagna
- Department of Biochemistry and Biophysics, Texas A&M University College Station TX 77843 USA
| | - Starla Glover
- Department of Chemistry, Ångström Laboratory, Uppsala University Box 523 75120 Uppsala Sweden
| | | | - Cecilia Tommos
- Department of Biochemistry and Biophysics, Texas A&M University College Station TX 77843 USA
| | - Leif Hammarström
- Department of Chemistry, Ångström Laboratory, Uppsala University Box 523 75120 Uppsala Sweden
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9
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Kang XW, Wang K, Zhang X, Zhong D, Ding B. Elementary Reactions in the Functional Triads of the Blue-Light Photoreceptor BLUF Domain. J Phys Chem B 2024; 128:2065-2075. [PMID: 38391132 DOI: 10.1021/acs.jpcb.3c07988] [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: 02/24/2024]
Abstract
The blue light using the flavin (BLUF) domain is one of the smallest photoreceptors in nature, which consists of a unique bidirectional electron-coupled proton relay process in its photoactivation reaction cycle. This perspective summarizes our recent efforts in dissecting the photocycle into three elementary processes, including proton-coupled electron transfer (PCET), proton rocking, and proton relay. Using ultrafast spectroscopy, we have determined the temporal sequence, rates, kinetic isotope effects (KIEs), and concertedness of these elementary steps. Our findings provide important implications for illuminating the photoactivation mechanism of the BLUF domain and suggest an engineering platform to characterize intricate reactions involving proton motions that are ubiquitous in nonphotosensitive protein machines.
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Affiliation(s)
- Xiu-Wen Kang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Kailin Wang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaofan Zhang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dongping Zhong
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Department of Physics, Department of Chemistry and Biochemistry, and Programs of Biophysics, Programs of Chemical Physics, and Programs of Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Bei Ding
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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10
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Migliore A, Messina A. Controlling the charge-transfer dynamics of two-level systems around avoided crossings. J Chem Phys 2024; 160:084112. [PMID: 38415830 DOI: 10.1063/5.0188749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/01/2024] [Indexed: 02/29/2024] Open
Abstract
Two-level quantum systems are fundamental physical models that continue to attract growing interest due to their crucial role as a building block of quantum technologies. The exact analytical solution of the dynamics of these systems is central to control theory and its applications, such as that to quantum computing. In this study, we reconsider the two-state charge transfer problem by extending and using a methodology developed to study (pseudo)spin systems in quantum electrodynamics contexts. This approach allows us to build a time evolution operator for the charge transfer system and to show new opportunities for the coherent control of the system dynamics, with a particular emphasis on the critical dynamic region around the transition state coordinate, where the avoided crossing of the energy levels occurs. We identify and propose possible experimental implementations of a class of rotations of the charge donor (or acceptor) that endow the electronic coupling matrix element with a time-dependent phase that can be employed to realize controllable coherent dynamics of the system across the avoided level crossing. The analogy of these rotations to reference frame rotations in generalized semiclassical Rabi models is discussed. We also show that the physical rotations in the charge-transfer systems can be performed so as to implement quantum gates relevant to quantum computing. From an exquisitely physical-mathematical viewpoint, our approach brings to light situations in which the time-dependent state of the system can be obtained without resorting to the special functions appearing in the Landau-Zener approach.
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Affiliation(s)
- Agostino Migliore
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Antonino Messina
- Dipartimento di Matematica e Informatica, Università degli Studi di Palermo, Via Archirafi, 34, I-90123 Palermo, Italy
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11
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Ahn S, Son M, Singh V, Yun A, Baik MH, Byon HR. Stabilization of Naphthalene Diimide Anions by Ion Pair Formation in Nonaqueous Organic Redox Flow Batteries. J Am Chem Soc 2024; 146:4521-4531. [PMID: 38346143 DOI: 10.1021/jacs.3c11176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
In redox flow batteries, a compelling strategy for enhancing the charge capacity of redox-active organic molecules involves storing multiple electrons within a single molecule. However, this approach poses unique challenges such as chemical instability by forming radicals, elevated energy requirements, and unsustainable charge concentration. Ion pairing is a possible solution to achieve charge neutrality and engineer redox potential shifts but has received limited attention. In this study, we demonstrate that Li+ can stabilize naphthalene diimide (NDI) anions dissolved in acetonitrile and significantly shift the second cathodic potential close to the first. Our findings, supported by density functional theory calculations and Fourier transform infrared spectroscopy, indicate that dimeric NDI species form stable ion pairs with Li+. Conversely, K+ ions exhibit weak interactions, and cyclic voltammograms confirm significant potential shifts when stronger Lewis acids and solvents with lower donor numbers are employed. Galvanostatic examinations reveal a single voltage plateau with Li+, which indicates a rapid redox process involving doubly charged NDI2- with Li+. These aggregated ion pairs offer the additional benefits of hindering crossover events, contributing to excellent cyclability, and suppressing undesirable side reactions even after 1000 redox cycles.
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Affiliation(s)
- Seongmo Ahn
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Mina Son
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Vikram Singh
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Ariyeong Yun
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Mu-Hyun Baik
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea
| | - Hye Ryung Byon
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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12
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Chen C, Jin H, Wang P, Sun X, Jaroniec M, Zheng Y, Qiao SZ. Local reaction environment in electrocatalysis. Chem Soc Rev 2024; 53:2022-2055. [PMID: 38204405 DOI: 10.1039/d3cs00669g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Beyond conventional electrocatalyst engineering, recent studies have unveiled the effectiveness of manipulating the local reaction environment in enhancing the performance of electrocatalytic reactions. The general principles and strategies of local environmental engineering for different electrocatalytic processes have been extensively investigated. This review provides a critical appraisal of the recent advancements in local reaction environment engineering, aiming to comprehensively assess this emerging field. It presents the interactions among surface structure, ions distribution and local electric field in relation to the local reaction environment. Useful protocols such as the interfacial reactant concentration, mass transport rate, adsorption/desorption behaviors, and binding energy are in-depth discussed toward modifying the local reaction environment. Meanwhile, electrode physical structures and reaction cell configurations are viable optimization methods in engineering local reaction environments. In combination with operando investigation techniques, we conclude that rational modifications of the local reaction environment can significantly enhance various electrocatalytic processes by optimizing the thermodynamic and kinetic properties of the reaction interface. We also outline future research directions to attain a comprehensive understanding and effective modulation of the local reaction environment.
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Affiliation(s)
- Chaojie Chen
- School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Huanyu Jin
- School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Pengtang Wang
- School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Xiaogang Sun
- School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Mietek Jaroniec
- Department of Chemistry and Biochemistry & Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA
| | - Yao Zheng
- School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Shi-Zhang Qiao
- School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005, Australia.
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13
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Wu WY, Zheng WY, Chen WT, Tsai FT, Tsai ML, Pao CW, Chen JL, Liaw WF. Electronic Structure and Transformation of Dinitrosyl Iron Complexes (DNICs) Regulated by Redox Non-Innocent Imino-Substituted Phenoxide Ligand. Inorg Chem 2024; 63:2431-2442. [PMID: 38258796 PMCID: PMC10848267 DOI: 10.1021/acs.inorgchem.3c03367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 01/04/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024]
Abstract
The coupled NO-vibrational peaks [IR νNO 1775 s, 1716 vs, 1668 vs cm-1 (THF)] between two adjacent [Fe(NO)2] groups implicate the electron delocalization nature of the singly O-phenoxide-bridged dinuclear dinitrosyliron complex (DNIC) [Fe(NO)2(μ-ON2Me)Fe(NO)2] (1). Electronic interplay between [Fe(NO)2] units and [ON2Me]- ligand in DNIC 1 rationalizes that "hard" O-phenoxide moiety polarizes iron center(s) of [Fe(NO)2] unit(s) to enforce a "constrained" π-conjugation system acting as an electron reservoir to bestow the spin-frustrated {Fe(NO)2}9-{Fe(NO)2}9-[·ON2Me]2- electron configuration (Stotal = 1/2). This system plays a crucial role in facilitating the ligand-based redox interconversion, working in harmony to control the storage and redox-triggered transport of the [Fe(NO)2]10 unit, while preserving the {Fe(NO)2}9 core in DNICs {Fe(NO)2}9-[·ON2Me]2- [K-18-crown-6-ether)][(ON2Me)Fe(NO)2] (2) and {Fe(NO)2}9-[·ON2Me] [(ON2Me)Fe(NO)2][PF6] (3). Electrochemical studies suggest that the redox interconversion among [{Fe(NO)2}9-[·ON2Me]2-] DNIC 3 ↔ [{Fe(NO)2}9-[ON2Me]-] ↔ [{Fe(NO)2}9-[·ON2Me]] DNIC 2 are kinetically feasible, corroborated by the redox shuttle between O-bridged dimerized [(μ-ONMe)2Fe2(NO)4] (4) and [K-18-crown-6-ether)][(ONMe)Fe(NO)2] (5). In parallel with this finding, the electronic structures of [{Fe(NO)2}9-{Fe(NO)2}9-[·ON2Me]2-] DNIC 1, [{Fe(NO)2}9-[·ON2Me]2-] DNIC 2, [{Fe(NO)2}9-[·ON2Me]] DNIC 3, [{Fe(NO)2}9-[ONMe]-]2 DNIC 4, and [{Fe(NO)2}9-[·ONMe]2-] DNIC 5 are evidenced by EPR, SQUID, and Fe K-edge pre-edge analyses, respectively.
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Affiliation(s)
- Wun-Yan Wu
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Wei-Yuan Zheng
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Wei-Ting Chen
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Fu-Te Tsai
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ming-Li Tsai
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Chih-Wen Pao
- National Synchrotron Radiation
Research Center, Hsinchu 30013, Taiwan
| | - Jeng-Lung Chen
- National Synchrotron Radiation
Research Center, Hsinchu 30013, Taiwan
| | - Wen-Feng Liaw
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
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14
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Ramundo A, Janoš J, Muchová L, Šranková M, Dostál J, Kloz M, Vítek L, Slavíček P, Klán P. Visible-Light-Activated Carbon Monoxide Release from Porphyrin-Flavonol Hybrids. J Am Chem Soc 2024; 146:920-929. [PMID: 38157303 PMCID: PMC10785818 DOI: 10.1021/jacs.3c11426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 11/26/2023] [Accepted: 12/11/2023] [Indexed: 01/03/2024]
Abstract
We report on porphyrin-flavonol hybrids consisting of a porphyrin antenna and four covalently bound 3-hydroxyflavone (flavonol) groups, which act as highly efficient photoactivatable carbon monoxide (CO)-releasing molecules (photoCORMs). These bichromophoric systems enable activation of the UV-absorbing flavonol chromophore by visible light up to 650 nm and offer precise spatial and temporal control of CO administration. The physicochemical properties of the porphyrin antenna system can also be tuned by inserting a metal cation. Our computational study revealed that the process occurs via endergonic triplet-triplet energy transfer from porphyrin to flavonol and may become feasible thanks to flavonol energy stabilization upon intramolecular proton transfer. This mechanism was also indirectly supported by steady-state and transient absorption spectroscopy techniques. Additionally, the porphyrin-flavonol hybrids were found to be biologically benign. With four flavonol CO donors attached to a single porphyrin chromophore, high CO release yields, excellent uncaging cross sections, low toxicity, and CO therapeutic properties, these photoCORMs offer exceptional potential for their further development and future biological and medical applications.
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Affiliation(s)
- Andrea Ramundo
- Department
of Chemistry, Faculty of Science, Masaryk
University, Kamenice 5, 62500 Brno, Czech Republic
- RECETOX,
Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech
Republic
| | - Jiří Janoš
- Department
of Physical Chemistry, University of Chemistry
and Technology, Technická
5, 16628 Prague
6, Czech Republic
| | - Lucie Muchová
- Institute
of Medical Biochemistry and Laboratory Diagnostics, and 4th Department
of Internal Medicine, General University
Hospital in Prague and First Faculty of Medicine, Charles University, Na Bojišti 3, 12108 Prague 2, Czech Republic
| | - Mária Šranková
- Institute
of Medical Biochemistry and Laboratory Diagnostics, and 4th Department
of Internal Medicine, General University
Hospital in Prague and First Faculty of Medicine, Charles University, Na Bojišti 3, 12108 Prague 2, Czech Republic
| | - Jakub Dostál
- ELI
Beamlines Facility, The Extreme Light Infrastructure
ERIC, Za Radnicí 835, 25241 Dolní Břežany, Czech Republic
| | - Miroslav Kloz
- ELI
Beamlines Facility, The Extreme Light Infrastructure
ERIC, Za Radnicí 835, 25241 Dolní Břežany, Czech Republic
| | - Libor Vítek
- Institute
of Medical Biochemistry and Laboratory Diagnostics, and 4th Department
of Internal Medicine, General University
Hospital in Prague and First Faculty of Medicine, Charles University, Na Bojišti 3, 12108 Prague 2, Czech Republic
| | - Petr Slavíček
- Department
of Physical Chemistry, University of Chemistry
and Technology, Technická
5, 16628 Prague
6, Czech Republic
| | - Petr Klán
- Department
of Chemistry, Faculty of Science, Masaryk
University, Kamenice 5, 62500 Brno, Czech Republic
- RECETOX,
Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech
Republic
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15
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Cui K, Soudackov AV, Hammes-Schiffer S. Modeling the Weak pH Dependence of Proton-Coupled Electron Transfer for Tryptophan Derivatives. J Phys Chem Lett 2023; 14:10980-10987. [PMID: 38039095 DOI: 10.1021/acs.jpclett.3c02282] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2023]
Abstract
The oxidation of tryptophan (Trp) is an important step in many biological processes and often occurs by sequential or concerted proton-coupled electron transfer (PCET). The apparent rate constants for the photochemical oxidation of two Trp derivatives in water have been shown to be pH-independent at low pH and to exhibit weak pH dependence at higher pH. Herein, these systems are investigated with a general, multi-channel model that includes sequential and concerted mechanisms as well as various proton donors and acceptors. This model can reproduce the kinetic data for both Trp derivatives with physically meaningful parameters and suggests that the weak pH dependence may arise from the competition between OH- and H2O as proton acceptors in concerted PCET. Deprotonation of an ammonium group for one of the systems leads to a more complex pH dependence at higher pH. This work demonstrates the importance of considering multiple competing channels for the analysis of the pH dependence of apparent PCET rate constants.
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Affiliation(s)
- Kai Cui
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Alexander V Soudackov
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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16
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Latrache M, Lefebvre C, Abe M, Hoffmann N. Photochemically Induced Hydrogen Atom Transfer and Intramolecular Radical Cyclization Reactions with Oxazolones. J Org Chem 2023; 88:16435-16455. [PMID: 37983612 DOI: 10.1021/acs.joc.3c01951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Photochemically induced intramolecular hydrogen atom transfer in oxazolones is reported. An acetal or thioacetal function at the side chain acts as a hydrogen donor while the photochemical exited oxazolone is the acceptor. A one-step process─the electron and the proton are simultaneously transferred─is productive, while electron transfer followed by proton transfer is inefficient. Radical combination then takes place, leading to the formation of a C-C or C-N bond. The regioselectivity of the reaction is explained by the diradical/zwitterion dichotomy of radical intermediates at the singlet state. In the present case, the zwitterion structure plays a central role, and intramolecular electron transfer favors spin-orbit coupling and thus the intersystem crossing to the singlet state. The reaction of corresponding thioacetal derivatives is less efficient. In this case, photochemical electron transfer is competitive. The photoproducts resulting from C-C bond formation easily undergo stepwise thermal decarboxylation in which zwitterionic and polar transition states are involved. A computational study of this step has also been performed.
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Affiliation(s)
- Mohammed Latrache
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
| | - Corentin Lefebvre
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
| | - Manabu Abe
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Hiroshima Research Center for Photo-Drug-Delivery Systems (Hi-P-DDS), 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Norbert Hoffmann
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
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17
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Schneider JE, Anderson JS. Reconciling Imbalanced and Nonadiabatic Reactivity in Transition Metal-Oxo-Mediated Concerted Proton Electron Transfer (CPET). J Phys Chem Lett 2023; 14:9548-9555. [PMID: 37856336 DOI: 10.1021/acs.jpclett.3c02318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Recently, there have been several experimental demonstrations of how the rates of concerted proton electron transfer (CPET) are affected by stepwise thermodynamic parameters of only proton (ΔG°PT) or electron (ΔG°ET) transfer. Semiclassical structure-activity relationships have been invoked to rationalize these linear free energy relationships, but it is not clear how they would manifest in a nonadiabatic reaction. Using density functional theory calculations, we demonstrate how a decrease in ΔG°PT can lead to transition state imbalance in a nonadiabatic framework. We then use these calculations to anchor a theoretical model that reproduces experimental trends with ΔG°PT and ΔG°ET. Our results reconcile predictions from semiclassical transition state theory with models that treat proton transfer quantum mechanically in CPET reactivity, make new predictions about the importance of basicity for uphill CPET reactions, and suggest similar treatments may be possible for other nonadiabatic reactions.
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Affiliation(s)
- Joseph E Schneider
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - John S Anderson
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
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18
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Ćehić M, Nikšić-Franjić I. Reactions of a hydrogen atom with haloacetates in aqueous solutions: Computational evidence for proton-coupled electron transfer and competing mechanisms. J Comput Chem 2023; 44:2212-2222. [PMID: 37452597 DOI: 10.1002/jcc.27191] [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: 04/05/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023]
Abstract
A computational study of the mechanisms and kinetics of the aqueous reactions of a hydrogen atom with haloacetates is presented. Several mechanisms in the close competition are observed, such as proton-coupled electron transfer (PCET), hydrogen atom transfer (HAT), and halogen abstraction (XA). Computations predict that dechlorination takes place via PCET mechanisms and not via XA, as stated earlier, while XA is the fastest mechanism forIAc - . The reaction rate constants are reasonably well predicted within the theoretically most reliable canonical variational transition state theory with small curvature tunneling corrections and compared with the experimental ones. To reproduce the experimental rate constants of the debromination process it is necessary to include the PCET and XA cumulative values. Small curvature tunneling corrections to the rate constants are the highest for HAT and PCET mechanisms, up to 70 times larger than the Wigner, while variational effects for XA mechanisms are very small.
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Affiliation(s)
- Mirsada Ćehić
- Chair of Environmental Protection, University of Applied Sciences on Security and Safety, VSS, Zagreb, Croatia
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19
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Lebrette H, Srinivas V, John J, Aurelius O, Kumar R, Lundin D, Brewster AS, Bhowmick A, Sirohiwal A, Kim IS, Gul S, Pham C, Sutherlin KD, Simon P, Butryn A, Aller P, Orville AM, Fuller FD, Alonso-Mori R, Batyuk A, Sauter NK, Yachandra VK, Yano J, Kaila VRI, Sjöberg BM, Kern J, Roos K, Högbom M. Structure of a ribonucleotide reductase R2 protein radical. Science 2023; 382:109-113. [PMID: 37797025 PMCID: PMC7615503 DOI: 10.1126/science.adh8160] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 08/30/2023] [Indexed: 10/07/2023]
Abstract
Aerobic ribonucleotide reductases (RNRs) initiate synthesis of DNA building blocks by generating a free radical within the R2 subunit; the radical is subsequently shuttled to the catalytic R1 subunit through proton-coupled electron transfer (PCET). We present a high-resolution room temperature structure of the class Ie R2 protein radical captured by x-ray free electron laser serial femtosecond crystallography. The structure reveals conformational reorganization to shield the radical and connect it to the translocation path, with structural changes propagating to the surface where the protein interacts with the catalytic R1 subunit. Restructuring of the hydrogen bond network, including a notably short O-O interaction of 2.41 angstroms, likely tunes and gates the radical during PCET. These structural results help explain radical handling and mobilization in RNR and have general implications for radical transfer in proteins.
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Affiliation(s)
- Hugo Lebrette
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative, CNRS, Université Toulouse III, Toulouse, France
| | - Vivek Srinivas
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
| | - Juliane John
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
| | - Oskar Aurelius
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
- MAX IV Laboratory, Lund University, Lund, Sweden
| | - Rohit Kumar
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
| | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
| | - Aaron S. Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Abhishek Sirohiwal
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
| | - In-Sik Kim
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sheraz Gul
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Cindy Pham
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kyle D. Sutherlin
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Philipp Simon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Agata Butryn
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, United Kingdom
- Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | - Pierre Aller
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, United Kingdom
- Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | - Allen M. Orville
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, United Kingdom
- Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | | | | | | | - Nicholas K. Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vittal K. Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Ville R. I. Kaila
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Katarina Roos
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Martin Högbom
- Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden
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20
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Sutton SF, Rotteger CH, Jarman CK, Tarakeshwar P, Sayres SG. Ultrafast Proton Transfer and Contact Ion-Pair Formation in Formic Acid Clusters. J Phys Chem Lett 2023; 14:8306-8311. [PMID: 37681673 DOI: 10.1021/acs.jpclett.3c01654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
The ultrafast proton transfer dynamics of homogeneous formic acid clusters (FA)n, n < 10, are investigated with femtosecond time-resolved mass spectrometry. We monitor the proton transfer pathway following Rydberg state electronic relaxation and find that successful ion pair formation increases logarithmically with cluster size. Ab initio calculations demonstrate similar excitation/relaxation behavior for each cluster, revealing a contact ion pair forms between two molecules composing the cluster before finally a formate anion (HCOO-) is dissociated by the probe pulse. The sub-ps time scale for rearrangement and proton transfer increases almost linearly with cluster size, requiring ∼67 fs per additional formic acid molecule and ranging from 213 ± 51 fs for the trimer to 667 ± 116 fs for FA9. The near-linear trends measured for both rearrangement lifetime and ion pair formation suggest that proton transfer is unlikely in the formic acid dimer but becomes prominent in small clusters.
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Affiliation(s)
- Shaun F Sutton
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Chase H Rotteger
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Carter K Jarman
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | | | - Scott G Sayres
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
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21
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Shee M, Zhang D, Banerjee M, Roy S, Pal B, Anoop A, Yuan Y, Singh NDP. Interrogating bioinspired ESIPT/PCET-based Ir(iii)-complexes as organelle-targeted phototherapeutics: a redox-catalysis under hypoxia to evoke synergistic ferroptosis/apoptosis. Chem Sci 2023; 14:9872-9884. [PMID: 37736623 PMCID: PMC10510766 DOI: 10.1039/d3sc03096b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 08/25/2023] [Indexed: 09/23/2023] Open
Abstract
Installing proton-coupled electron transfer (PCET) in Ir-complexes is indeed a newly explored phenomenon, offering high quantum efficiency and tunable photophysics; however, the prospects for its application in various fields, including interrogating biological systems, are quite open and exciting. Herein, we developed various organelle-targeted Ir(iii)-complexes by leveraging the photoinduced PCET process to see the opportunities in phototherapeutic application and investigate the underlying mechanisms of action (MOAs). We diversified the ligands' nature and also incorporated a H-bonded benzimidazole-phenol (BIP) moiety with π-conjugated ancillary ligands in Ir(iii) to study the excited-state intramolecular proton transfer (ESIPT) process for tuning dual emission bands and to tempt excited-state PCET. These visible or two-photon-NIR light activatable Ir-catalysts generate reactive hydroxyl radicals (˙OH) and simultaneously oxidize electron donating biomolecules (1,4-dihydronicotinamide adenine dinucleotide or glutathione) to disrupt redox homeostasis, downregulate the GPX4 enzyme, and amplify oxidative stress and lipid peroxide (LPO) accumulation. Our homogeneous photocatalytic platform efficiently triggers organelle dysfunction mediated by a Fenton-like pathway with spatiotemporal control upon illumination to evoke ferroptosis poised with the synergistic action of apoptosis in a hypoxic environment leading to cell death. Ir2 is the most efficient photochemotherapy agent among others, which provided profound cytophototoxicity to 4T1 and MCF-7 cancerous cells and inhibited solid hypoxic tumor growth in vitro and in vivo.
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Affiliation(s)
- Maniklal Shee
- Department of Chemistry, Indian Institute of Technology Kharagpur West Bengal-721302 India
| | - Dan Zhang
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus Guangzhou 511442 PR China
| | - Moumita Banerjee
- Department of Chemistry, Indian Institute of Technology Kharagpur West Bengal-721302 India
| | - Samrat Roy
- Department of Physics, Indian Institute of Science Education and Research Kolkata Mohanpur West Bengal 741246 India
| | - Bipul Pal
- Department of Physics, Indian Institute of Science Education and Research Kolkata Mohanpur West Bengal 741246 India
| | - Anakuthil Anoop
- Department of Chemistry, Indian Institute of Technology Kharagpur West Bengal-721302 India
| | - Youyong Yuan
- School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus Guangzhou 511442 PR China
| | - N D Pradeep Singh
- Department of Chemistry, Indian Institute of Technology Kharagpur West Bengal-721302 India
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22
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Cassone G, Saija F, Sponer J, Shaik S. The Reactivity-Enhancing Role of Water Clusters in Ammonia Aqueous Solutions. J Phys Chem Lett 2023; 14:7808-7813. [PMID: 37623433 PMCID: PMC10494223 DOI: 10.1021/acs.jpclett.3c01810] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/22/2023] [Indexed: 08/26/2023]
Abstract
Among the many prototypical acid-base systems, ammonia aqueous solutions hold a privileged place, owing to their omnipresence in various planets and their universal solvent character. Although the theoretical optimal water-ammonia molar ratio to form NH4+ and OH- ion pairs is 50:50, our ab initio molecular dynamics simulations show that the tendency of forming these ionic species is inversely (directly) proportional to the amount of ammonia (water) in ammonia aqueous solutions, up to a water-ammonia molar ratio of ∼75:25. Here we prove that the reactivity of these liquid mixtures is rooted in peculiar microscopic patterns emerging at the H-bonding scale, where the highly orchestrated motion of 5 solvating molecules modulates proton transfer events through local electric fields. This study demonstrates that the reaction of water with NH3 is catalyzed by a small cluster of water molecules, in which an H atom possesses a high local electric field, much like the effect observed in catalysis by water droplets [ PNAS 2023, 120, e2301206120].
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Affiliation(s)
- Giuseppe Cassone
- Institute
for Physical-Chemical Processes, Italian
National Research Council (CNR-IPCF), Viale Stagno d’Alcontres 37, 98158 Messina, Italy
| | - Franz Saija
- Institute
for Physical-Chemical Processes, Italian
National Research Council (CNR-IPCF), Viale Stagno d’Alcontres 37, 98158 Messina, Italy
| | - Jiri Sponer
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czechia
| | - Sason Shaik
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
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23
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Nakanishi T, Hori Y, Shigeta Y, Sato H, Kiyanagi R, Munakata K, Ohhara T, Okazawa A, Shimada R, Sakamoto A, Sato O. Development of an Iron(II) Complex Exhibiting Thermal- and Photoinduced Double Proton-Transfer-Coupled Spin Transition in a Short Hydrogen Bond. J Am Chem Soc 2023; 145:19177-19181. [PMID: 37623927 DOI: 10.1021/jacs.3c06323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Multiple proton transfer (PT) controllable by external stimuli plays a crucial role in fundamental chemistry, biological activity, and material science. However, in crystalline systems, controlling multiple PT, which results in a distinct protonation state, remains challenging. In this study, we developed a novel tridentate ligand and iron(II) complex with a short hydrogen bond (HB) that exhibits a PT-coupled spin transition (PCST). Single-crystal X-ray and neutron diffraction measurements revealed that the positions of the two protons in the complex can be controlled by temperature and photoirradiation based on the thermal- and photoinduced PCST. The obtained results suggest that designing molecules that form short HBs is a promising approach for developing multiple PT systems in crystals.
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Affiliation(s)
- Takumi Nakanishi
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yuta Hori
- Center for Computational Sciences, University of Tsukuba, Tsukuba 305-8577, Japan
| | - Yasuteru Shigeta
- Center for Computational Sciences, University of Tsukuba, Tsukuba 305-8577, Japan
| | - Hiroyasu Sato
- Rigaku Corporation, 3-9-12 Matsubaracho, Akishima, Tokyo 196-8666, Japan
| | - Ryoji Kiyanagi
- J-PARC center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Koji Munakata
- J-PARC center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Takashi Ohhara
- J-PARC center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Atsushi Okazawa
- Department of Electrical Engineering and Bioscience, Waseda University, Okubo 3-4-1, Shinjuku-ku, Tokyo, 169-8555, Japan
| | - Rintaro Shimada
- Graduate School of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan
| | - Akira Sakamoto
- Graduate School of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan
| | - Osamu Sato
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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24
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Mandal A, Taylor MA, Weight BM, Koessler ER, Li X, Huo P. Theoretical Advances in Polariton Chemistry and Molecular Cavity Quantum Electrodynamics. Chem Rev 2023; 123:9786-9879. [PMID: 37552606 PMCID: PMC10450711 DOI: 10.1021/acs.chemrev.2c00855] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Indexed: 08/10/2023]
Abstract
When molecules are coupled to an optical cavity, new light-matter hybrid states, so-called polaritons, are formed due to quantum light-matter interactions. With the experimental demonstrations of modifying chemical reactivities by forming polaritons under strong light-matter interactions, theorists have been encouraged to develop new methods to simulate these systems and discover new strategies to tune and control reactions. This review summarizes some of these exciting theoretical advances in polariton chemistry, in methods ranging from the fundamental framework to computational techniques and applications spanning from photochemistry to vibrational strong coupling. Even though the theory of quantum light-matter interactions goes back to the midtwentieth century, the gaps in the knowledge of molecular quantum electrodynamics (QED) have only recently been filled. We review recent advances made in resolving gauge ambiguities, the correct form of different QED Hamiltonians under different gauges, and their connections to various quantum optics models. Then, we review recently developed ab initio QED approaches which can accurately describe polariton states in a realistic molecule-cavity hybrid system. We then discuss applications using these method advancements. We review advancements in polariton photochemistry where the cavity is made resonant to electronic transitions to control molecular nonadiabatic excited state dynamics and enable new photochemical reactivities. When the cavity resonance is tuned to the molecular vibrations instead, ground-state chemical reaction modifications have been demonstrated experimentally, though its mechanistic principle remains unclear. We present some recent theoretical progress in resolving this mystery. Finally, we review the recent advances in understanding the collective coupling regime between light and matter, where many molecules can collectively couple to a single cavity mode or many cavity modes. We also lay out the current challenges in theory to explain the observed experimental results. We hope that this review will serve as a useful document for anyone who wants to become familiar with the context of polariton chemistry and molecular cavity QED and thus significantly benefit the entire community.
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Affiliation(s)
- Arkajit Mandal
- Department
of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Michael A.D. Taylor
- The
Institute of Optics, Hajim School of Engineering, University of Rochester, Rochester, New York 14627, United States
| | - Braden M. Weight
- Department
of Physics and Astronomy, University of
Rochester, Rochester, New York 14627, United
States
| | - Eric R. Koessler
- Department
of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
| | - Xinyang Li
- Department
of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
- Theoretical
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Pengfei Huo
- Department
of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
- The
Institute of Optics, Hajim School of Engineering, University of Rochester, Rochester, New York 14627, United States
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25
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Koone J, Simmang M, Saenger DL, Hunsicker-Wang LM, Shaw BF. Charge Regulation in a Rieske Proton Pump Pinpoints Zero, One, and Two Proton-Coupled Electron Transfer. J Am Chem Soc 2023; 145:16488-16497. [PMID: 37486967 PMCID: PMC10402712 DOI: 10.1021/jacs.3c03006] [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: 03/22/2023] [Indexed: 07/26/2023]
Abstract
The degree to which redox-driven proton pumps regulate net charge during electron transfer (ΔZET) remains undetermined due to difficulties in measuring the net charge of solvated proteins. Values of ΔZET can reflect reorganization energies or redox potentials associated with ET and can be used to distinguish ET from proton(s)-coupled electron transfer (PCET). Here, we synthesized protein "charge ladders" of a Rieske [2Fe-2S] subunit from Thermus thermophilus (truncTtRp) and made 120 electrostatic measurements of ΔZET across pH. Across pH 5-10, truncTtRp is suspected of transitioning from ET to PCET, and then to two proton-coupled ET (2PCET). Upon reduction, we found that truncTtRp became more negative at pH 6.0 by one unit (ΔZET = -1.01 ± 0.14), consistent with single ET; was isoelectric at pH 8.8 (ΔZET = -0.01 ± 0.45), consistent with PCET; and became more positive at pH 10.6 (ΔZET = +1.37 ± 0.60), consistent with 2PCET. These ΔZET values are attributed to protonation of H154 and H134. Across pH, redox potentials of TtRp (measured previously) correlated with protonation energies of H154 and H134 and ΔZET for truncTtRp, supporting a discrete proton pumping mechanism for Rieske proteins at the Fe-coordinating histidines.
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Affiliation(s)
- Jordan
C. Koone
- Department
of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, United States
| | - Mikaela Simmang
- Department
of Chemistry, Trinity University, San Antonio, Texas 78212, United States
| | - Devin L. Saenger
- Department
of Chemistry, Trinity University, San Antonio, Texas 78212, United States
| | | | - Bryan F. Shaw
- Department
of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, United States
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26
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Hwang D, Wrigley LM, Lee M, Sobolewski AL, Domcke W, Schlenker CW. Local Hydrogen Bonding Determines Branching Pathways in Intermolecular Heptazine Photochemistry. J Phys Chem B 2023. [PMID: 37471476 DOI: 10.1021/acs.jpcb.3c01397] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Heptazine is the molecular core of the widely studied photocatalyst carbon nitride. By analyzing the excited-state intermolecular proton-coupled electron-transfer (PCET) reaction between a heptazine derivative and a hydrogen-atom donor substrate, we are able to spectroscopically identify the resultant heptazinyl reactive radical species on a picosecond time scale. We provide detailed spectroscopic characterization of the tri-anisole heptazine:4-methoxyphenol hydrogen-bonded intermolecular complex (TAHz:MeOPhOH), using femtosecond transient absorption spectroscopy and global analysis, to reveal distinct product absorption signatures at ∼520, 1250, and 1600 nm. We assign these product peaks to the hydrogenated TAHz radical (TAHzH•) based on control experiments utilizing 1,4-dimethoxybenzene (DMB), which initiates electron transfer without concomitant proton transfer, i.e., no excited-state PCET. Additional control experiments with radical quenchers, protonation agents, and UV-vis-NIR spectroelectrochemistry also corroborate our product peak assignments. These spectral assignments allowed us to monitor the influence of the local hydrogen-bonding environment on the resulting evolution of photochemical products from excited-state PCET of heptazines. We observe that the preassociation of heptazine with the substrate in solution is extremely sensitive to the hydrogen-bond-accepting character of the solvent. This sensitivity directly influences which product signatures we detect with time-resolved spectroscopy. The spectral signature of the TAHzH• radical assigned in this work will facilitate future in-depth analysis of heptazine and carbon nitride photochemistry. Our results may also be utilized for designing improved PCET-based photochemical systems that will require precise control over local molecular environments. Examples include applications such as preparative synthesis involving organic photoredox catalysis, on-site solar water purification, as well as photocatalytic water splitting and artificial photosynthesis.
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Affiliation(s)
- Doyk Hwang
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Liam M Wrigley
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Micah Lee
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | | | - Wolfgang Domcke
- Department of Chemistry, Technical University of Munich, D-85747 Garching, Germany
| | - Cody W Schlenker
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, Washington 98195-1652, United States
- Clean Energy Institute, University of Washington, Seattle, Washington 98195-1653, United States
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27
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Dey A, Ghorai N, Das A, Ghosh HN. Effects of hydrogen bonding on intramolecular/intermolecular proton-coupled electron transfer using a Ruthenium-anthraquinone dyad in ultrafast time domain. J Photochem Photobiol A Chem 2023. [DOI: 10.1016/j.jphotochem.2023.114709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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28
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Immel JR, Alghafli BM, Rodríguez Ugalde AA, Bloom S. Aqueous Flavin Photoredox Catalysis Drives Exclusive C3-Alkylation of Indolyl Radical Cations in Route to Unnatural Tryptophan Mimetics. Org Lett 2023; 25:3818-3822. [PMID: 37191639 PMCID: PMC11055211 DOI: 10.1021/acs.orglett.3c01398] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
One way to build chemical diversity into indoles is to oxidize them to indolyl radical cations (Ind•+). These intermediates can accept new functional groups across C2-C3 bonds or independently at C2. Less encountered is selective diversification at C3, a position plagued by competing dearomative side reactions. We disclose an aqueous photoredox-catalyzed method for transforming Ind•+ into C3-substituted tryptophan mimetics that uses water as a transient protecting group to guide site-selective C3 alkylation.
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Affiliation(s)
- Jacob R Immel
- Department of Medicinal Chemistry, The University of Kansas, Gray Little Hall, Lawrence, Kansas 66045, United States
| | - Bayan M Alghafli
- Department of Medicinal Chemistry, The University of Kansas, Gray Little Hall, Lawrence, Kansas 66045, United States
| | - Allen Alonso Rodríguez Ugalde
- Department of Medicinal Chemistry, The University of Kansas, Gray Little Hall, Lawrence, Kansas 66045, United States
| | - Steven Bloom
- Department of Medicinal Chemistry, The University of Kansas, Gray Little Hall, Lawrence, Kansas 66045, United States
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29
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Li J, Shi Y, Cheng T. Electronic coupling and electron transfer in hydrogen-bonded mixed-valence compounds. Phys Chem Chem Phys 2023. [PMID: 37158078 DOI: 10.1039/d3cp01337e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Electron transfer provided by hydrogen bonds represents a unique and highly significant area of research, as it has a crucial role to play in a wide variety of chemical and biological systems. The hydrogen-bonded mixed-valence system, in the form of donor-hydrogen bond-acceptor, provides an ideal platform for exploring thermally-induced electron transfer across this non-covalent unit. Over the past decades, ongoing progress has been made in this field. Here we critically assess some studies on the qualitative and quantitative evaluation of electronic coupling and thermal electron transfer across hydrogen bond interface. Additionally, selected experimental examples are discussed in terms of intervalence charge transfer, with particular attention paid to the proton-coupled and often overlooked proton-uncoupled electron transfer pathway in hydrogen-bonded mixed-valence systems. We further highlight the major limitations of this research area and suggest potential directions for future exploration.
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Affiliation(s)
- Juanjuan Li
- Shandong Provincial Key Laboratory of Molecular Engineering, School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China
| | - Yuqing Shi
- Shandong Provincial Key Laboratory of Molecular Engineering, School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China
| | - Tao Cheng
- Shandong Provincial Key Laboratory of Molecular Engineering, School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China
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30
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Chalopin Y, Cramer SP, Arragain S. Phonon-assisted electron-proton transfer in [FeFe] hydrogenases: Topological role of clusters. Biophys J 2023; 122:1557-1567. [PMID: 36960530 PMCID: PMC10147833 DOI: 10.1016/j.bpj.2023.03.027] [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: 11/01/2022] [Revised: 02/27/2023] [Accepted: 03/16/2023] [Indexed: 03/25/2023] Open
Abstract
[FeFe] hydrogenases are enzymes that have acquired a unique capacity to synthesize or consume molecular hydrogen (H2). This function relies on a complex catalytic mechanism involving the active site and two distinct electron and proton transfer networks working in concert. By an analysis based on terahertz vibrations of [FeFe] hydrogenase structure, we are able to predict and identify the existence of rate-promoting vibrations at the catalytic site and the coupling with functional residues involved in reported electron and proton transfer networks. Our findings suggest that the positioning of the cluster is influenced by the response of the scaffold to thermal fluctuations, which in turn drives the formation of networks for electron transfer through phonon-assisted mechanisms. Thus, we address the problem of linking the molecular structure to the catalytic function through picosecond dynamics, while raising the functional gain brought by the cofactors or clusters, using the concept of fold-encoded localized vibrations.
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Affiliation(s)
- Yann Chalopin
- Laboratoire d'Energétique Macroscopique et Moléculaire, Combustion (EM2C), CNRS/CentraleSupélec, University of Paris-Saclay, Gif-sur-Yvette, France.
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31
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Héroux P, Belyaev I, Chamberlin K, Dasdag S, De Salles AAA, Rodriguez CEF, Hardell L, Kelley E, Kesari KK, Mallery-Blythe E, Melnick RL, Miller AB, Moskowitz JM. Cell Phone Radiation Exposure Limits and Engineering Solutions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:5398. [PMID: 37048013 PMCID: PMC10094704 DOI: 10.3390/ijerph20075398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/17/2023] [Accepted: 03/31/2023] [Indexed: 06/19/2023]
Abstract
In the 1990s, the Institute of Electrical and Electronics Engineers (IEEE) restricted its risk assessment for human exposure to radiofrequency radiation (RFR) in seven ways: (1) Inappropriate focus on heat, ignoring sub-thermal effects. (2) Reliance on exposure experiments performed over very short times. (3) Overlooking time/amplitude characteristics of RFR signals. (4) Ignoring carcinogenicity, hypersensitivity, and other health conditions connected with RFR. (5) Measuring cellphone Specific Absorption Rates (SAR) at arbitrary distances from the head. (6) Averaging SAR doses at volumetric/mass scales irrelevant to health. (7) Using unrealistic simulations for cell phone SAR estimations. Low-cost software and hardware modifications are proposed here for cellular phone RFR exposure mitigation: (1) inhibiting RFR emissions in contact with the body, (2) use of antenna patterns reducing the Percent of Power absorbed in the Head (PPHead) and body and increasing the Percent of Power Radiated for communications (PPR), and (3) automated protocol-based reductions of the number of RFR emissions, their duration, or integrated dose. These inexpensive measures do not fundamentally alter cell phone functions or communications quality. A health threat is scientifically documented at many levels and acknowledged by industries. Yet mitigation of RFR exposures to users does not appear as a priority with most cell phone manufacturers.
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Affiliation(s)
- Paul Héroux
- Department of Epidemiology, Biostatistics and Occupational Health, Faculty of Medicine, McGill University, Montreal, QC H3A 1G1, Canada
| | - Igor Belyaev
- Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, 814 38 Bratislava, Slovakia
| | - Kent Chamberlin
- Department of Electrical and Computer Engineering, University of New Hampshire, Durham, NH 03824, USA
| | - Suleyman Dasdag
- Biophysics Department, Medical School, Istanbul Medeniyet University, Istanbul 34700, Turkey
| | - Alvaro Augusto Almeida De Salles
- Graduate Program on Electrical Engineering (PPGEE), Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil
| | | | - Lennart Hardell
- Department of Oncology, Orebro University Hospital, 701 85 Orebro, Sweden (Retired)
- The Environment and Cancer Research Foundation, 702 17 Orebro, Sweden
| | - Elizabeth Kelley
- ICBE-EMF and International EMF Scientist Appeal, and Electromagnetic Safety Alliance, Tempe, AZ 85282, USA
| | - Kavindra Kumar Kesari
- Department of Applied Physics, School of Science, Aalto University, 02150 Espoo, Finland
| | - Erica Mallery-Blythe
- Physicians’ Health Initiative for Radiation and Environment, East Sussex TN6, UK
- British Society of Ecological Medicine, London W1W 6DB, UK
- Oceania Radiofrequency Scientific Advisory Association, Scarborough, QLD 4020, Australia
| | - Ronald L. Melnick
- National Toxicology Program (Retired), National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC 27709, USA
- Ron Melnick Consulting LLC, North Logan, UT 84341, USA
| | - Anthony B. Miller
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5T 3M7, Canada
| | - Joel M. Moskowitz
- School of Public Health, University of California, Berkeley, CA 94704, USA
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32
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Maejima S, Yamaguchi E, Itoh A. Visible-Light-Induced Regioselective Functionalization of α-Olefin: Development of One-Pot Photo-Synthesis of C 3-Substituted Dihydrobenzofurans. Org Lett 2023; 25:1856-1861. [PMID: 36866934 DOI: 10.1021/acs.orglett.3c00335] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
A method for the catalytic regioselective synthesis of C3-substituted dihydrobenzofurans (DHBs) via [2 + 2] photocycloaddition of alkene and p-benzoquinone is developed. This method realizes the rapid synthesis of DHBs with readily available substrates and simple reaction conditions by using Lewis acid B(C6F5)3 and Lewis base P(o-tol)3 as a catalyst in combination with the classical Paternò-Büchi reaction.
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Affiliation(s)
- Saki Maejima
- Laboratory of Pharmaceuticals Synthetic Chemistry, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Eiji Yamaguchi
- Laboratory of Pharmaceuticals Synthetic Chemistry, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
| | - Akichika Itoh
- Laboratory of Pharmaceuticals Synthetic Chemistry, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
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33
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Rousseau BJG, Migliore A, Stanley RJ, Beratan DN. Adenine Fine-Tunes DNA Photolyase's Repair Mechanism. J Phys Chem B 2023; 127:2941-2954. [PMID: 36947863 DOI: 10.1021/acs.jpcb.3c00566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
The comparative study of DNA repair by mesophilic and extremophilic photolyases helps us understand the evolution of these enzymes and their role in preserving life on our changing planet. The mechanism of repair of cyclobutane pyrimidine dimer lesions in DNA by electron transfer from the flavin adenine dinucleotide cofactor is the subject of intense interest. The role of adenine in mediating this process remains unresolved. Using microsecond molecular dynamics simulations, we find that adenine mediates the electron transfer in both mesophile and extremophile DNA photolyases through a similar mechanism. In fact, in all photolyases studied, the molecular conformations with the largest electronic couplings between the enzyme cofactor and DNA show the presence of adenine in 10-20% of the strongest-coupling tunneling pathways between the atoms of the electron donor and acceptor. Our theoretical analysis finds that adenine serves the critical role of fine-tuning rather than maximizing the donor-acceptor coupling within the range appropriate for the repair function.
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Affiliation(s)
- Benjamin J G Rousseau
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Agostino Migliore
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Robert J Stanley
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - David N Beratan
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
- Department of Physics, Duke University, Durham, North Carolina 27708, United States
- Department of Biochemistry, Duke University, Durham, North Carolina 27710, United States
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34
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Zhao N, Goetz MK, Schneider JE, Anderson JS. Testing the Limits of Imbalanced CPET Reactivity: Mechanistic Crossover in H-Atom Abstraction by Co(III)-Oxo Complexes. J Am Chem Soc 2023; 145:5664-5673. [PMID: 36867838 PMCID: PMC10023487 DOI: 10.1021/jacs.2c10553] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Transition metal-oxo complexes are key intermediates in a variety of oxidative transformations, notably C-H bond activation. The relative rate of C-H bond activation mediated by transition metal-oxo complexes is typically predicated on substrate bond dissociation free energy in cases with a concerted proton-electron transfer (CPET). However, recent work has demonstrated that alternative stepwise thermodynamic contributions such as acidity/basicity or redox potentials of the substrate/metal-oxo may dominate in some cases. In this context, we have found basicity-governed concerted activation of C-H bonds with the terminal CoIII-oxo complex PhB(tBuIm)3CoIIIO. We have been interested in testing the limits of such basicity-dependent reactivity and have synthesized an analogous, more basic complex, PhB(AdIm)3CoIIIO, and studied its reactivity with H-atom donors. This complex displays a higher degree of imbalanced CPET reactivity than PhB(tBuIm)3CoIIIO with C-H substrates, and O-H activation of phenol substrates displays mechanistic crossover to stepwise proton transfer-electron transfer (PTET) reactivity. Analysis of the thermodynamics of proton transfer (PT) and electron transfer (ET) reveals a distinct thermodynamic crossing point between concerted and stepwise reactivity. Furthermore, the relative rates of stepwise and concerted reactivity suggest that maximally imbalanced systems provide the fastest CPET rates up to the point of mechanistic crossover, which results in slower product formation.
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Affiliation(s)
- Norman Zhao
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | | | - Joseph E. Schneider
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - John S. Anderson
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
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35
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Yuan B, Tang SY, Zhou S. Size Effects in Gas-phase C-H Activation. Chemphyschem 2023; 24:e202200769. [PMID: 36420565 DOI: 10.1002/cphc.202200769] [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: 10/14/2022] [Revised: 11/23/2022] [Accepted: 11/23/2022] [Indexed: 11/25/2022]
Abstract
The gas-phase clusters reaction permits addressing fundamental aspects of the challenges related to C-H activation. The size effect plays a key role in the activation processes as it may substantially affect both the reactivity and selectivity. In this paper, we reviewed the size effect related to the hydrocarbon oxidation by early transition metal oxides and main group metal oxides, methane activation mediated by late transition metals. Based on mass-spectrometry experiments in conjunction with quantum chemical calculations, mechanistic discussions were reviewed to present how and why the size greatly regulates the reactivity and product distribution.
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Affiliation(s)
- Bowei Yuan
- College of Chemical and Biological Engineering, Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, Zhejiang University, 310027, Hangzhou, P. R. China.,Institute of Zhejiang University - Quzhou, Zheda Rd. #99, 324000, Quzhou, P.R. China
| | - Shi-Ya Tang
- State Key Laboratory of Safety and Control for Chemicals, SINOPEC Research Institute of Safety Engineering Co., Ltd., Qingdao, 266000, P. R. China
| | - Shaodong Zhou
- College of Chemical and Biological Engineering, Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, Zhejiang University, 310027, Hangzhou, P. R. China.,Institute of Zhejiang University - Quzhou, Zheda Rd. #99, 324000, Quzhou, P.R. China
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36
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Montoya-Castillo A, Markland TE. A derivation of the conditions under which bosonic operators exactly capture fermionic structure and dynamics. J Chem Phys 2023; 158:094112. [PMID: 36889969 DOI: 10.1063/5.0138664] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
The dynamics of many-body fermionic systems are important in problems ranging from catalytic reactions at electrochemical surfaces to transport through nanojunctions and offer a prime target for quantum computing applications. Here, we derive the set of conditions under which fermionic operators can be exactly replaced by bosonic operators that render the problem amenable to a large toolbox of dynamical methods while still capturing the correct dynamics of n-body operators. Importantly, our analysis offers a simple guide on how one can exploit these simple maps to calculate nonequilibrium and equilibrium single- and multi-time correlation functions essential in describing transport and spectroscopy. We use this to rigorously analyze and delineate the applicability of simple yet effective Cartesian maps that have been shown to correctly capture the correct fermionic dynamics in select models of nanoscopic transport. We illustrate our analytical results with exact simulations of the resonant level model. Our work provides new insights as to when one can leverage the simplicity of bosonic maps to simulate the dynamics of many-electron systems, especially those where an atomistic representation of nuclear interactions becomes essential.
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Affiliation(s)
| | - Thomas E Markland
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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37
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Demchenko AP. Proton transfer reactions: from photochemistry to biochemistry and bioenergetics. BBA ADVANCES 2023. [DOI: 10.1016/j.bbadva.2023.100085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
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38
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Fang W, Feng S, Jiang Z, Liang W, Li P, Wang B. Understanding the Key Roles of pH Buffer in Accelerating Lignin Degradation by Lignin Peroxidase. JACS AU 2023; 3:536-549. [PMID: 36873691 PMCID: PMC9976348 DOI: 10.1021/jacsau.2c00649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 06/18/2023]
Abstract
pH buffer plays versatile roles in both biology and chemistry. In this study, we unravel the critical role of pH buffer in accelerating degradation of the lignin substrate in lignin peroxidase (LiP) using QM/MM MD simulations and the nonadiabatic electron transfer (ET) and proton-coupled electron transfer (PCET) theories. As a key enzyme involved in lignin degradation, LiP accomplishes the oxidation of lignin via two consecutive ET reactions and the subsequent C-C cleavage of the lignin cation radical. The first one involves ET from Trp171 to the active species of Compound I, while the second one involves ET from the lignin substrate to the Trp171 radical. Differing from the common view that pH = 3 may enhance the oxidizing power of Cpd I via protonation of the protein environment, our study shows that the intrinsic electric fields have minor effects on the first ET step. Instead, our study shows that the pH buffer of tartaric acid plays key roles during the second ET step. Our study shows that the pH buffer of tartaric acid can form a strong H-bond with Glu250, which can prevent the proton transfer from the Trp171-H•+ cation radical to Glu250, thereby stabilizing the Trp171-H•+ cation radical for the lignin oxidation. In addition, the pH buffer of tartaric acid can enhance the oxidizing power of the Trp171-H•+ cation radical via both the protonation of the proximal Asp264 and the second-sphere H-bond with Glu250. Such synergistic effects of pH buffer facilitate the thermodynamics of the second ET step and reduce the overall barrier of lignin degradation by ∼4.3 kcal/mol, which corresponds to a rate acceleration of 103-fold that agrees with experiments. These findings not only expand our understanding on pH-dependent redox reactions in both biology and chemistry but also provide valuable insights into tryptophan-mediated biological ET reactions.
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Affiliation(s)
- Wenhan Fang
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
| | - Shishi Feng
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
| | - Zhihui Jiang
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
| | - Wanzhen Liang
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
| | - Pengfei Li
- Department
of Chemistry and Biochemistry, Loyola University
Chicago, 1068 W. Sheridan Rd., Chicago, Illinois60660, United States
| | - Binju Wang
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
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39
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Hashemi A, Peljo P, Laasonen K. Understanding Electron Transfer Reactions Using Constrained Density Functional Theory: Complications Due to Surface Interactions. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:3398-3407. [PMID: 36865990 PMCID: PMC9969872 DOI: 10.1021/acs.jpcc.2c06537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/25/2023] [Indexed: 06/18/2023]
Abstract
The kinetic rates of electrochemical reactions depend on electrodes and molecules in question. In a flow battery, where the electrolyte molecules are charged and discharged on the electrodes, the efficiency of the electron transfer is of crucial importance for the performance of the device. The purpose of this work is to present a systematic atomic-level computational protocol for studying electron transfer between electrolyte and electrode. The computations are done by using constrained density functional theory (CDFT) to ensure that the electron is either on the electrode or in the electrolyte. The ab initio molecular dynamics (AIMD) is used to simulate the movement of the atoms. We use the Marcus theory to predict electron transfer rates and the combined CDFT-AIMD approach to compute the parameters for the Marcus theory where it is needed. We model the electrode with a single layer of graphene and methylviologen, 4,4'-dimethyldiquat, desalted basic red 5, 2-hydroxy-1,4-naphthaquinone, and 1,1-di(2-ethanol)-4,4-bipyridinium were selected for the electrolyte molecules. All of these molecules undergo consecutive electrochemical reactions with one electron being transferred at each stage. Because of significant electrode-molecule interactions, it is not possible to evaluate outer-sphere ET. This theoretical study contributes toward the development of a realistic-level prediction of electron transfer kinetics suitable for energy storage applications.
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Affiliation(s)
- Arsalan Hashemi
- Research
Group of Computational Chemistry, Department of Chemistry and Materials
Science, Aalto University, FI-00076 Aalto, Finland
| | - Pekka Peljo
- Research
Group of Battery Materials and Technologies, Department of Mechanical
and Materials Engineering, Faculty of Technology, University of Turku, 20014 Turun Yliopisto, Finland
| | - Kari Laasonen
- Research
Group of Computational Chemistry, Department of Chemistry and Materials
Science, Aalto University, FI-00076 Aalto, Finland
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40
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Chen Z, Kang XW, Zhou Y, Zhou Z, Tang S, Zou S, Wang K, Huang J, Ding B, Zhong D. Dissecting the Ultrafast Stepwise Bidirectional Proton Relay in a Blue-Light Photoreceptor. J Am Chem Soc 2023; 145:3394-3400. [PMID: 36722850 DOI: 10.1021/jacs.2c10206] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Proton relays through H-bond networks are essential in realizing the functionality of protein machines such as in photosynthesis and photoreceptors. It has been challenging to dissect the rates and energetics of individual proton-transfer steps during the proton relay. Here, we have designed a proton rocking blue light using a flavin (BLUF) domain with the flavin mononucleotide (FMN)-glutamic acid (E)-tryptophan (W) triad and have resolved the four individual proton-transfer steps kinetically using ultrafast spectroscopy. We have found that after the photo-induced charge separation forming FMN·-/E-COOH/WH·+, the proton first rapidly jumps from the bridging E-COOH to FMN- (τfPT2 = 3.8 ps; KIE = 1.0), followed by a second proton transfer from WH·+ to E-COO- (τfPT1 = 336 ps; KIE = 2.6) which immediately rocks back to W· (τrPT1 = 85 ps; KIE = 6.7), followed by a proton return from FMNH· to E-COO- (τrPT2 = 34 ps; KIE = 3.3) with the final charge recombination between FMN·- and WH·+ to close the reaction cycle. Our results revisited the Grotthuss mechanism on the ultrafast timescale using the BLUF domain as a paradigm protein.
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Affiliation(s)
- Zijing Chen
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Xiu-Wen Kang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Yalin Zhou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Zhongneng Zhou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Siwei Tang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Shuhua Zou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Kailin Wang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Jiulong Huang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Bei Ding
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Dongping Zhong
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China.,Department of Physics, Department of Chemistry and Biochemistry, and Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, Ohio43210, United States.,School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai200240, China
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41
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Cao W, Xia GJ, Yao Z, Zeng KH, Qiao Y, Wang YG. Aldehyde Hydrogenation by Pt/TiO 2 Catalyst in Aqueous Phase: Synergistic Effect of Oxygen Vacancy and Solvent Water. JACS AU 2023; 3:143-153. [PMID: 36711102 PMCID: PMC9875238 DOI: 10.1021/jacsau.2c00560] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/06/2022] [Accepted: 12/08/2022] [Indexed: 06/18/2023]
Abstract
The aldehyde hydrogenation for stabilizing and upgrading biomass is typically performed in aqueous phase with supported metal catalysts. By combining density functional theory calculations and ab initio molecular dynamics simulations, the model reaction of formaldehyde hydrogenation with a Pt/TiO2 catalyst is investigated with explicit solvent water molecules. In aqueous phase, both the O vacancy (Ov) on support and solvent molecules could donate charges to a Pt cluster, where the Ov could dominantly reduce the Pt cluster from positive to negative. During the formaldehyde hydrogenation, the water molecules could spontaneously protonate the O in the aldehyde group by acid/base exchange, generating the OH* at the metal-support interface by long-range proton transfer. By comparing the stoichiometric and reduced TiO2 support, it is found that the further hydrogenation of OH* is hard on the positively charged Pt cluster over stoichiometric TiO2. However, with the presence of Ov on reduced support, the OH* hydrogenation could become not only exergonic but also kinetically more facile, which prohibits the catalyst from poisoning. This mechanism suggests that both the proton transfer from solvent water molecules and the easier OH* hydrogenation from Ov could synergistically promote aldehyde hydrogenation. That means, even for such simple hydrogenation in water, the catalytic mechanism could explicitly relate to all of the metal cluster, oxide support, and solvent waters. Considering the ubiquitous Ov defects in reducible oxide supports and the common aqueous environment, this synergistic effect may not be exclusive to Pt/TiO2, which can be crucial for supported metal catalysts in biomass conversion.
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42
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Tyson K, Tangtartharakul CB, Zeug M, Findling N, Haddy A, Hvastkovs E, Choe JY, Kim JE, Offenbacher AR. Electrochemical and Structural Study of the Buried Tryptophan in Azurin: Effects of Hydration and Polarity on the Redox Potential of W48. J Phys Chem B 2023; 127:133-143. [PMID: 36542812 PMCID: PMC9841983 DOI: 10.1021/acs.jpcb.2c06677] [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: 09/19/2022] [Revised: 11/16/2022] [Indexed: 12/24/2022]
Abstract
Tryptophan serves as an important redox-active amino acid in mediating electron transfer and mitigating oxidative damage in proteins. We previously showed a difference in electrochemical potentials for two tryptophan residues in azurin with distinct hydrogen-bonding environments. Here, we test whether reducing the side chain bulk at position Phe110 to Leu, Ser, or Ala impacts the electrochemical potentials (E°) for tryptophan at position 48. X-ray diffraction confirmed the influx of crystallographically resolved water molecules for both the F110A and F110L tyrosine free azurin mutants. The local environments of W48 in all azurin mutants were further evaluated by UV resonance Raman (UVRR) spectroscopy to probe the impact of mutations on hydrogen bonding and polarity. A correlation between the frequency of the ω17 mode─considered a vibrational marker for hydrogen bonding─and E° is proposed. However, the trend is opposite to the expectation from a previous study on small molecules. Density functional theory calculations suggest that the ω17 mode reflects hydrogen bonding as well as local polarity. Further, the UVRR data reveal different intensity/frequency shifts of the ω9/ω10 vibrational modes that characterize the local H-bonding environments of tryptophan. The cumulative data support that the presence of water increases E° and reveal properties of the protein microenvironment surrounding tryptophan.
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Affiliation(s)
- Kristin Tyson
- Department
of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Chanin B. Tangtartharakul
- Department
of Chemistry and Biochemistry, University
of California at San Diego, La Jolla, California 92093, United States
| | - Matthias Zeug
- Department
of Chemistry, East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville North Carolina, 27858, United States
| | - Nathan Findling
- Department
of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Alice Haddy
- Department
of Chemistry and Biochemistry, University
of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Eli Hvastkovs
- Department
of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Jun-yong Choe
- Department
of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
- Department
of Chemistry, East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville North Carolina, 27858, United States
| | - Judy E. Kim
- Department
of Chemistry and Biochemistry, University
of California at San Diego, La Jolla, California 92093, United States
| | - Adam R. Offenbacher
- Department
of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
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43
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Ariyageadsakul P, Baeck KK. Nuclear wave-packet-propagation-based study of the electron-coupled, proton-transfer process in the charge-transfer state of FHCl exhibiting three electronic states in full-dimensional space. J Chem Phys 2023; 158:014302. [PMID: 36610955 DOI: 10.1063/5.0131104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The charge-transfer (CT) excited state of FHCl (F+H-Cl-), generated by the photodetachment of an electron from its precursor anion (FHCl-) by a photon energy of ∼9.5 eV, is a realistic prototype of two bidirectional-coupled reaction pathways, namely the proton-transfer (PT) and electron-transfer (ET) channels, that produce F + HCl and FH + Cl combinations, respectively. The early-time dynamics of the CT was studied via the time-dependent propagations of nuclear wave packets comprising three nonadiabatically coupled electronic states defined within a three-dimensional space. The detailed analyses of the early-time dynamics revealed an interesting phenomenon in which the onset of PT was ∼80 fs earlier than that of ET, indicating that PT dominated ET in this case. A more significant finding was that the proper adjustment of the electronic-charge distribution for the onset of ET was obtained ∼80 fs after the onset of PT; this adjustment was mediated by the initial movement of the H atom, i.e., the F-H vibration mode. To avail experimental observables, the branching ratio, χ = PT/(PT + ET), and absorption spectrum generating the neutral FHCl molecule from its precursor anion were also simulated. The results further demonstrated the dependences of the χs and spectrum on the change in the initial vibration level of the precursor anion, as well as the isotopic substitution of the connecting H atom with deuterium, tritium, and muonium.
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Affiliation(s)
- Pinit Ariyageadsakul
- Department of Chemistry, Gangneung-Wonju National University, Gangneung, Gangwon-do 25457, Republic of Korea
| | - Kyoung Koo Baeck
- Department of Chemistry, Gangneung-Wonju National University, Gangneung, Gangwon-do 25457, Republic of Korea
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44
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Hontani Y, Mehlhorn J, Domratcheva T, Beck S, Kloz M, Hegemann P, Mathes T, Kennis JTM. Spectroscopic and Computational Observation of Glutamine Tautomerization in the Blue Light Sensing Using Flavin Domain Photoreaction. J Am Chem Soc 2023; 145:1040-1052. [PMID: 36607126 PMCID: PMC9853863 DOI: 10.1021/jacs.2c10621] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Blue light sensing using flavin (BLUF) domains constitute a family of flavin-binding photoreceptors of bacteria and eukaryotic algae. BLUF photoactivation proceeds via a light-driven hydrogen-bond switch among flavin adenine dinucleotide (FAD) and glutamine and tyrosine side chains, whereby FAD undergoes electron and proton transfer with tyrosine and is subsequently re-oxidized by a hydrogen back-shuttle in picoseconds, constituting an important model system to understand proton-coupled electron transfer in biology. The specific structure of the hydrogen-bond patterns and the prevalence of glutamine tautomeric states in dark-adapted (DA) and light-activated (LA) states have remained controversial. Here, we present a combined femtosecond stimulated Raman spectroscopy (FSRS), computational chemistry, and site-selective isotope labeling Fourier-transform infrared spectroscopy (FTIR) study of the Slr1694 BLUF domain. FSRS showed distinct vibrational bands from the FADS1 singlet excited state. We observed small but significant shifts in the excited-state vibrational frequency patterns of the DA and LA states, indicating that these frequencies constitute a sensitive probe for the hydrogen-bond arrangement around FAD. Excited-state model calculations utilizing four different realizations of hydrogen bond patterns and glutamine tautomeric states were consistent with a BLUF reaction model that involved glutamine tautomerization to imidic acid, accompanied by a rotation of its side chain. A combined FTIR and double-isotope labeling study, with 13C labeling of FAD and 15N labeling of glutamine, identified the glutamine imidic acid C═N stretch vibration in the LA state and the Gln C═O in the DA state. Hence, our study provides support for glutamine tautomerization and side-chain rotation in the BLUF photoreaction.
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Affiliation(s)
- Yusaku Hontani
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, 1081 HV Amsterdam, De Boelelaan, The Netherlands
| | - Jennifer Mehlhorn
- Institut
für Biologie, Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - Tatiana Domratcheva
- Department
of Biomolecular Mechanisms, Max Planck Institute
for Medical Research, 69120 Heidelberg, Germany,Department
of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sebastian Beck
- Department
of Chemistry, Humboldt-Universität
zu Berlin, Brook-Taylor-Str.
2, 12489 Berlin, Germany
| | - Miroslav Kloz
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, 1081 HV Amsterdam, De Boelelaan, The Netherlands,Institute
of Physics, ELI-Beamlines, Na Slovance 2, 182
21 Praha 8, Czech Republic
| | - Peter Hegemann
- Institut
für Biologie, Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - Tilo Mathes
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, 1081 HV Amsterdam, De Boelelaan, The Netherlands,Institut
für Biologie, Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - John T. M. Kennis
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, 1081 HV Amsterdam, De Boelelaan, The Netherlands,
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45
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Modern Photocatalytic Strategies in Natural Product Synthesis. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2023; 120:1-104. [PMID: 36587307 DOI: 10.1007/978-3-031-11783-1_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Modern photocatalysis has proven its generality for the development and functionalization of native functionalities. To date, the field has found broad applications in diverse research areas, including the total synthesis of natural products. This contribution covers recent reports of total syntheses involving as a key step a photocatalytic reaction. Among the selected examples, the photocatalytic processes proceed in a highly chemo-, regio-, and stereoselective manner, thereby allowing the rapid access to structurally complex architectures under light-driven conditions.
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46
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Ramanathan D, Shi Q, Xu M, Chang R, Peñín B, Funes-Ardoiz I, Ye J. Catalytic asymmetric deuterosilylation of exocyclic olefins with mannose-derived thiols and deuterium oxide. Org Chem Front 2023. [DOI: 10.1039/d2qo01979e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Metal-free, photoinduced asymmetric deuterosilylation of exocyclic olefins has been achieved using a mannose-derived thiol catalyst.
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Affiliation(s)
- Devenderan Ramanathan
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qinglong Shi
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Meichen Xu
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Rui Chang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Beatriz Peñín
- Department of Chemistry, Centro de Investigación en Síntesis Química (CISQ), Universidad de La Rioja, Madre de Dios 53, 26006 Logroño, Spain
| | - Ignacio Funes-Ardoiz
- Department of Chemistry, Centro de Investigación en Síntesis Química (CISQ), Universidad de La Rioja, Madre de Dios 53, 26006 Logroño, Spain
| | - Juntao Ye
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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47
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Allen JP, Chamberlain KD, Williams JC. Identification of amino acid residues in a proton release pathway near the bacteriochlorophyll dimer in reaction centers from Rhodobacter sphaeroides. PHOTOSYNTHESIS RESEARCH 2023; 155:23-34. [PMID: 36197600 DOI: 10.1007/s11120-022-00968-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
Insight into control of proton transfer, a crucial attribute of cellular functions, can be gained from investigations of bacterial reaction centers. While the uptake of protons associated with the reduction of the quinone is well characterized, the release of protons associated with the oxidized bacteriochlorophyll dimer has been poorly understood. Optical spectroscopy and proton release/uptake measurements were used to examine the proton release characteristics of twelve mutant reaction centers, each containing a change in an amino acid residue near the bacteriochlorophyll dimer. The mutant reaction centers had optical spectra similar to wild-type and were capable of transferring electrons to the quinones after light excitation of the bacteriochlorophyll dimer. They exhibited a large range in the extent of proton release and in the slow recovery of the optical signal for the oxidized dimer upon continuous illumination. Key roles were indicated for six amino acid residues, Thr L130, Asp L155, Ser L244, Arg M164, Ser M190, and His M193. Analysis of the results points to a hydrogen-bond network that contains these residues, with several additional residues and bound water molecules, forming a proton transfer pathway. In addition to proton transfer, the properties of the pathway are proposed to be responsible for the very slow charge recombination kinetics observed after continuous illumination. The characteristics of this pathway are compared to proton transfer pathways near the secondary quinone as well as those found in photosystem II and cytochrome c oxidase.
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Affiliation(s)
- J P Allen
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA.
| | - K D Chamberlain
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
| | - J C Williams
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
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48
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Salamatian AA, Bren KL. Bioinspired and biomolecular catalysts for energy conversion and storage. FEBS Lett 2023; 597:174-190. [PMID: 36331366 DOI: 10.1002/1873-3468.14533] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022]
Abstract
Metalloenzymes are remarkable for facilitating challenging redox transformations with high efficiency and selectivity. In the area of alternative energy, scientists aim to capture these properties in bioinspired and engineered biomolecular catalysts for the efficient and fast production of fuels from low-energy feedstocks such as water and carbon dioxide. In this short review, efforts to mimic biological catalysts for proton reduction and carbon dioxide reduction are highlighted. Two important recurring themes are the importance of the microenvironment of the catalyst active site and the key role of proton delivery to the active site in achieving desired reactivity. Perspectives on ongoing and future challenges are also provided.
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Affiliation(s)
| | - Kara L Bren
- Department of Chemistry, University of Rochester, NY, USA
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49
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Sarhangi SM, Matyushov DV. Theory of Protein Charge Transfer: Electron Transfer between Tryptophan Residue and Active Site of Azurin. J Phys Chem B 2022; 126:10360-10373. [PMID: 36459590 DOI: 10.1021/acs.jpcb.2c05258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
One reaction step in the conductivity relay of azurin, electron transfer between the Cu-based active site and the tryptophan residue, is studied theoretically and by classical molecular dynamics simulations. Oxidation of tryptophan results in electrowetting of this residue. This structural change makes the free energy surfaces of electron transfer nonparabolic as described by the Q-model of electron transfer. We analyze the medium dynamical effect on protein electron transfer produced by coupled Stokes-shift dynamics and the dynamics of the donor-acceptor distance modulating electron tunneling. The equilibrium donor-acceptor distance falls in the plateau region of the rate constant, where it is determined by the protein-water dynamics, and the probability of electron tunneling does not affect the rate. The crossover distance found here puts most intraprotein electron-transfer reactions under the umbrella of dynamical control. The crossover between the medium-controlled and tunneling-controlled kinetics is combined with the effect of the protein-water medium on the activation barrier to formulate principles of tunability of protein-based charge-transfer chains. The main principle in optimizing the activation barrier is the departure from the Gaussian-Gibbsian statistics of fluctuations promoting activated transitions. This is achieved either by incomplete (nonergodic) sampling, breaking the link between the Stokes-shift and variance reorganization energies, or through wetting-induced structural changes of the enzyme's active site.
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Affiliation(s)
- Setare Mostajabi Sarhangi
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona85287-1504, United States
| | - Dmitry V Matyushov
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona85287-1504, United States
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Semiclassical Theory of Multistage Nonequilibrium Electron Transfer in Macromolecular Compounds in Polar Media with Several Relaxation Timescales. Int J Mol Sci 2022; 23:ijms232415793. [PMID: 36555434 PMCID: PMC9779366 DOI: 10.3390/ijms232415793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Many specific features of ultrafast electron transfer (ET) reactions in macromolecular compounds can be attributed to nonequilibrium configurations of intramolecular vibrational degrees of freedom and the environment. In photoinduced ET, nonequilibrium nuclear configurations are often produced at the stage of optical excitation, but they can also be the result of electron tunneling itself, i.e., fast redistribution of charges within the macromolecule. A consistent theoretical description of ultrafast ET requires an explicit consideration of the nuclear subsystem, including its evolution between electron jumps. In this paper, the effect of the multi-timescale nuclear reorganization on ET transitions in macromolecular compounds is studied, and a general theory of ultrafast ET in non-Debye polar environments with a multi-component relaxation function is developed. Particular attention is paid to designing the multidimensional space of nonequilibrium nuclear configurations, as well as constructing the diabatic free energy surfaces for the ET states. The reorganization energies of individual ET transitions, the equilibrium energies of ET states, and the relaxation properties of the environment are used as input data for the theory. The effect of the system-environment interaction on the ET kinetics is discussed, and mechanisms for enhancing the efficiency of charge separation in macromolecular compounds are analyzed.
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