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Capone M, Narzi D, Tychengulova A, Guidoni L. On the comparison between differential vibrational spectroscopy spectra and theoretical data in the carboxyl region of photosystem II. PHYSIOLOGIA PLANTARUM 2019; 166:33-43. [PMID: 30801735 DOI: 10.1111/ppl.12949] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
Understanding the structural modification experienced by the Mn4 CaO5 oxygen-evolving complex of photosystem II along the Kok-Joliot's cycle has been a challenge for both theory and experiments since many decades. In particular, differential infrared spectroscopy was extensively used to probe the surroundings of the reaction center, to catch spectral changes between different S-states along the catalytic cycle. Because of the complexity of the signals, only a limited quantity of identified peaks have been assigned so far, also because of the difficulty of a direct comparison with theoretical calculations. In the present work, we critically reconsider the comparison between differential vibrational spectroscopy and theoretical calculations performed on the structural models of the photosystem II active site and an inorganic structural mimic. Several factors are currently limiting the reliability of a quantitative comparison, such as intrinsic errors associated to theoretical methods, and most of all, the uncertainty attributed to the lack of knowledge about the localization of the underlying structural changes. Critical points in this comparison are extensively discussed. Comparing several computational data of differential S2 /S1 infrared spectroscopy, we have identified weak and strong points in their interpretation when compared with experimental spectra.
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Affiliation(s)
- Matteo Capone
- Department of Information Engineering, Computational Science and Mathematics, Università dell'Aquila, 67100, L'Aquila, Italy
| | - Daniele Narzi
- Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Aliya Tychengulova
- Department of Basic Sciences Applied for Engineering, "Sapienza" Università di Roma, 00185, Rome, Italy
| | - Leonardo Guidoni
- Department of Physical and Chemical Science, Università dell'Aquila, 67100, L'Aquila, Italy
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Guo Z, Barry BA. Cryogenic Trapping and Isotope Editing Identify a Protonated Water Cluster as an Intermediate in the Photosynthetic Oxygen-Evolving Reaction. J Phys Chem B 2016; 120:8794-808. [DOI: 10.1021/acs.jpcb.6b05283] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhanjun Guo
- School of Chemistry and Biochemistry
and Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Bridgette A Barry
- School of Chemistry and Biochemistry
and Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Sander W, Roy S, Polyak I, Ramirez-Anguita JM, Sanchez-Garcia E. The Phenoxyl Radical–Water Complex—A Matrix Isolation and Computational Study. J Am Chem Soc 2012; 134:8222-30. [DOI: 10.1021/ja301528w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wolfram Sander
- Lehrstuhl für Organische
Chemie II, Ruhr-Universität Bochum, D-44801 Bochum, Germany
| | - Saonli Roy
- Lehrstuhl für Organische
Chemie II, Ruhr-Universität Bochum, D-44801 Bochum, Germany
| | - Iakov Polyak
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1,
D-45470 Mülheim an der Ruhr, Germany
| | | | - Elsa Sanchez-Garcia
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1,
D-45470 Mülheim an der Ruhr, Germany
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Orio M, Jarjayes O, Baptiste B, Philouze C, Duboc C, Mathias JL, Benisvy L, Thomas F. Geometric and Electronic Structures of Phenoxyl Radicals Hydrogen Bonded to Neutral and Cationic Partners. Chemistry 2012; 18:5416-29. [DOI: 10.1002/chem.201102854] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Indexed: 11/06/2022]
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Barry BA. Proton coupled electron transfer and redox active tyrosines in Photosystem II. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2011; 104:60-71. [PMID: 21419640 PMCID: PMC3164834 DOI: 10.1016/j.jphotobiol.2011.01.026] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 01/25/2011] [Accepted: 01/31/2011] [Indexed: 11/30/2022]
Abstract
In this article, progress in understanding proton coupled electron transfer (PCET) in Photosystem II is reviewed. Changes in acidity/basicity may accompany oxidation/reduction reactions in biological catalysis. Alterations in the proton transfer pathway can then be used to alter the rates of the electron transfer reactions. Studies of the bioenergetic complexes have played a central role in advancing our understanding of PCET. Because oxidation of the tyrosine results in deprotonation of the phenolic oxygen, redox active tyrosines are involved in PCET reactions in several enzymes. This review focuses on PCET involving the redox active tyrosines in Photosystem II. Photosystem II catalyzes the light-driven oxidation of water and reduction of plastoquinone. Photosystem II provides a paradigm for the study of redox active tyrosines, because this photosynthetic reaction center contains two tyrosines with different roles in catalysis. The tyrosines, YZ and YD, exhibit differences in kinetics and midpoint potentials, and these differences may be due to noncovalent interactions with the protein environment. Here, studies of YD and YZ and relevant model compounds are described.
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Affiliation(s)
- Bridgette A Barry
- School of Chemistry and Biochemistry and The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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Gross R, Wolf MMN, Schumann C, Friedman N, Sheves M, Li L, Engelhard M, Trentmann O, Neuhaus HE, Diller R. Primary photoinduced protein response in bacteriorhodopsin and sensory rhodopsin II. J Am Chem Soc 2010; 131:14868-78. [PMID: 19778046 DOI: 10.1021/ja904218n] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Essential for the biological function of the light-driven proton pump, bacteriorhodopsin (BR), and the light sensor, sensory rhodopsin II (SRII), is the coupling of the activated retinal chromophore to the hosting protein moiety. In order to explore the dynamics of this process we have performed ultrafast transient mid-infrared spectroscopy on isotopically labeled BR and SRII samples. These include SRII in D(2)O buffer, BR in H(2)(18)O medium, SRII with (15)N-labeled protein, and BR with (13)C(14)(13)C(15)-labeled retinal chromophore. Via observed shifts of infrared difference bands after photoexcitation and their kinetics we provide evidence for nonchromophore bands in the amide I and the amide II region of BR and SRII. A band around 1550 cm(-1) is very likely due to an amide II vibration. In the amide I region, contributions of modes involving exchangeable protons and modes not involving exchangeable protons can be discerned. Observed bands in the amide I region of BR are not due to bending vibrations of protein-bound water molecules. The observed protein bands appear in the amide I region within the system response of ca. 0.3 ps and in the amide II region within 3 ps, and decay partially in both regions on a slower time scale of 9-18 ps. Similar observations have been presented earlier for BR5.12, containing a nonisomerizable chromophore (R. Gross et al. J. Phys. Chem. B 2009, 113, 7851-7860). Thus, the results suggest a common mechanism for ultrafast protein response in the artificial and the native system besides isomerization, which could be induced by initial chromophore polarization.
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Affiliation(s)
- Ruth Gross
- University of Kaiserslautern, Department of Physics, Erwin-Schrodinger-Strasse, 67663 Kaiserslautern, Germany
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Arora H, Philouze C, Jarjayes O, Thomas F. CoII, NiII, CuII and ZnII complexes of a bipyridine bis-phenol conjugate: Generation and properties of coordinated radical species. Dalton Trans 2010; 39:10088-98. [DOI: 10.1039/c0dt00342e] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Amsden JJ, Kralj JM, Bergo VB, Spudich EN, Spudich JL, Rothschild KJ. Different structural changes occur in blue- and green-proteorhodopsins during the primary photoreaction. Biochemistry 2008; 47:11490-8. [PMID: 18842006 DOI: 10.1021/bi800945t] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We examine the structural changes during the primary photoreaction in blue-absorbing proteorhodopsin (BPR), a light-driven retinylidene proton pump, using low-temperature FTIR difference spectroscopy. Comparison of the light-induced BPR difference spectrum recorded at 80 K to that of green-absorbing proteorhodopsin (GPR) reveals that there are several differences in the BPR and GPR primary photoreactions despite the similar structure of the retinal chromophore and all-trans --> 13-cis isomerization. Strong bands near 1700 cm(-1) assigned previously to a change in hydrogen bonding of Asn230 in GPR are still present in BPR. However, additional bands in the same region are assigned on the basis of site-directed mutagenesis to changes occurring in Gln105. In the amide II region, bands are assigned on the basis of total (15)N labeling to structural changes of the protein backbone, although no such bands were previously observed for GPR. A band at 3642 cm(-1) in BPR, assigned to the OH stretching mode of a water molecule on the basis of H2(18)O substitution, appears at a different frequency than a band at 3626 cm(-1) previously assigned to a water molecule in GPR. However, the substitution of Gln105 for Leu105 in BPR leads to the appearance of both bands at 3642 and 3626 cm(-1), indicating the waters assigned in BPR and GPR exist in separate distinct locations and can coexist in the GPR-like Q105L mutant of BPR. These results indicate that there exist significant differences in the conformational changes occurring in these two types proteorhodopsin during the initial photoreaction despite their similar chromophore structures, which might reflect a different arrangement of water in the active site as well as substitution of a hydrophilic for hydrophobic residue at residue 105.
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Affiliation(s)
- Jason J Amsden
- Department of Physics, Photonics Center, and Molecular Biophysics Laboratory, Boston University, Boston, Massachusetts 02215, USA
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Pujols-Ayala I, Barry BA. Tyrosyl radicals in Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2004; 1655:205-16. [PMID: 15100033 DOI: 10.1016/j.bbabio.2003.07.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2003] [Revised: 07/31/2003] [Accepted: 07/31/2003] [Indexed: 11/23/2022]
Abstract
In PSII, there are two redox-active tyrosines, D and Z, with different midpoint potentials and different reduction kinetics. The factors responsible for these functional differences have not yet been elucidated. Recent model compound studies of tyrosinate and of tyrosine-containing dipeptides have demonstrated that perturbations of the amino and amide/imide group occur when the tyrosyl aromatic ring is oxidized [J. Am. Chem. Soc. 124 (2002) 5496]. Accompanying density functional calculations suggested that this perturbation is due to spin density delocalization from the aromatic ring onto the amino nitrogen. The implication of this finding is that spin density delocalization may occur in redox-active, tyrosine-containing enzymes, like Photosystem II. In this paper, we review the supporting evidence for the hypothesis that tyrosyl radical spin density delocalizes into the peptide bond in a conformationally sensitive, sequence-dependent manner. Our experimental measurements on tyrosyl radicals in dipeptides have suggested that the magnitude of the putative spin migration may be sequence-dependent. Vibrational spectroscopic studies on the tyrosyl radicals in Photosystem II, which are consistent with spin migration, are reviewed. Migration of the unpaired spin may provide a mechanism for control of the direction and possibly the rate of electron transfer.
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Affiliation(s)
- Idelisa Pujols-Ayala
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 1479 Gortner Ave., St. Paul, MN 55108, USA
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Fang Y, Liu L, Feng Y, Li XS, Guo QX. Effects of Hydrogen Bonding to Amines on the Phenol/Phenoxyl Radical Oxidation. J Phys Chem A 2002. [DOI: 10.1021/jp014425z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ying Fang
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Lei Liu
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Yong Feng
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Xiao-Song Li
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Qing-Xiang Guo
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
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Affiliation(s)
- R P Pesavento
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Ayala I, Kim S, Barry BA. A Difference Fourier transform infrared study of tyrosyl radical Z* decay in photosystem II. Biophys J 1999; 77:2137-44. [PMID: 10512833 PMCID: PMC1300494 DOI: 10.1016/s0006-3495(99)77054-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Photosystem II (PSII) contains a redox-active tyrosine, Z* Difference Fourier transform infrared (FTIR) spectroscopy can be used to obtain structural information about this species, which is a neutral radical, Z*, in the photooxidized form. Previously, we have used isotopic labeling, inhibitors, and site-directed mutagenesis to assign a vibrational line at 1478 cm(-1) to Z*; these studies were performed on highly resolved PSII preparations at pH 7.5, under conditions where Q(A)(-) and Q(B)(-) make no detectable contribution to the vibrational spectrum (Kim, Ayala, Steenhuis, Gonzalez, Razeghifard, and Barry. 1998. Biochim. Biophys. Acta. 1366:330-354). Here, time-resolved infrared data associated with the reduction of tyrosyl radical Z* were acquired from spinach core PSII preparations at pH 6.0. Electron paramagnetic resonance spectroscopy and fluorescence control experiments were employed to measure the rate of Q(A)(-) and Z* decay. Q(B)(-) did not recombine with Z* under these conditions. Difference FTIR spectra, acquired over this time regime, exhibited time-dependent decreases in the amplitude of a 1478 cm(-1) line. Quantitative comparison of the rates of Q(A)(-) and Z* decay with the decay of the 1478 cm(-1) line supported the assignment of a 1478 cm(-1) component to Z*. Comparison with difference FTIR spectra obtained from PSII samples, in which tyrosine is labeled, supported this conclusion and identified other spectral components assignable to Z* and Z. To our knowledge, this is the first kinetic study to use quantitative comparison of kinetic constants in order to assign spectral features to Z*.
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Affiliation(s)
- I Ayala
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, St. Paul, Minnesota 55108-1022, USA
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Steenhuis JJ, Hutchison RS, Barry BA. Alterations in carboxylate ligation at the active site of photosystem II. J Biol Chem 1999; 274:14609-16. [PMID: 10329653 DOI: 10.1074/jbc.274.21.14609] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photosystem II (PSII) is the photosynthetic enzyme catalyzing the oxidation of water and reduction of plastoquinone (Q). This reaction occurs at a catalytic site containing four manganese atoms and cycling among five oxidation states, the Sn states, where n refers to the number of oxidizing equivalents stored. Biochemical and spectroscopic techniques have been used previously to conclude that aspartate 170 in the D1 subunit influences the structure and function of the PSII active site (Boerner, R. J., Nguyen, A. P., Barry, B. A., and Debus, R. J. (1992) Biochemistry 31, 6660-6672). Substitution of glutamate for aspartate 170 resulted in an assembled manganese cluster, which was capable of enzymatic turnover, but at lower steady-state oxygen evolution rates. Here, we obtained the difference (light-minus-dark) Fourier transform IR spectrum associated with the S2Q--minus-S1Q transition by illumination of oxygen-evolving wild-type and DE170D1 PSII preparations at 200 K. These spectra are known to be dominated by contributions from carboxylic acid and carboxylate residues that are close to or ligating the manganese cluster. Substitution of glutamate for aspartate 170 results in alterations in the S2Q--minus-S1Q spectrum; the alterations are consistent with a change in carboxylate coordination to manganese or calcium. In particular, the spectra are consistent with a shift from bridging/bidentate carboxylates in wild-type PSII to unidentate carboxylate ligation in DE170D1 PSII.
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Affiliation(s)
- J J Steenhuis
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, St. Paul, Minnesota 55108-1022, USA
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Kim S, Barry BA. The protein environment surrounding tyrosyl radicals D. and Z. in photosystem II: a difference Fourier-transform infrared spectroscopic study. Biophys J 1998; 74:2588-600. [PMID: 9591683 PMCID: PMC1299599 DOI: 10.1016/s0006-3495(98)77965-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Photosystem II contains two redox-active tyrosine residues, termed D and Z, which have different midpoint potentials and oxidation/reduction kinetics. To understand the functional properties of redox-active tyrosines, we report a difference Fourier-transform infrared (FT-IR) spectroscopic study of these species. Vibrational spectra associated with the oxidation of each tyrosine residue are acquired; electron paramagnetic resonance (EPR) and fluorescence experiments demonstrate that there is no detectable contribution of Q(A)- to these spectra. Vibrational lines are assigned to the radicals by isotopic labeling of tyrosine. Global 15N labeling, 2H exchange, and changes in pH identify differences in the reversible interactions of the two redox-active tyrosines with N-containing, titratable amino acid side chains in their environments. To identify the amino acid residue that contributes to the spectrum of D, mutations at His189 in the D2 polypeptide were examined. Mutations at this site result in substantial changes in the spectrum of tyrosine D. Previously, mutations at the analogous histidine, His190 in the D1 polypeptide, were shown to have no significant effect on the FT-IR spectrum of tyrosine Z (Bernard, M. T., et al. 1995. J. Biol. Chem. 270:1589-1594). A disparity in the number of accessible, proton-accepting groups could influence electron transfer rates and energetics and account for functional differences between the two redox-active tyrosines.
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Affiliation(s)
- S Kim
- Department of Biochemistry, University of Minnesota, St. Paul 55108-1022, USA
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Diner BA. [23]Application of spectroscopic techniques to the Study of Photosystem II Mutations Engineered in Synechocystis and Chlamydomonas. Methods Enzymol 1998. [DOI: 10.1016/s0076-6879(98)97025-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Kim S, Liang J, Barry BA. Chemical complementation identifies a proton acceptor for redox-active tyrosine D in photosystem II. Proc Natl Acad Sci U S A 1997; 94:14406-11. [PMID: 9405625 PMCID: PMC24999 DOI: 10.1073/pnas.94.26.14406] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/1997] [Accepted: 10/27/1997] [Indexed: 02/05/2023] Open
Abstract
Through the use of site-directed mutagenesis and chemical rescue, we have identified the proton acceptor for redox-active tyrosine D in photosystem II (PSII). Effects of chemical rescue on the tyrosyl radical were monitored by EPR spectroscopy. We also have acquired the Fourier-transform infrared (FT-IR) spectrum associated with the oxidation of tyrosine D and concomitant protonation of the acceptor. Mutant and isotopically labeled PSII samples are used to assign vibrational lines in the 3,600-3,100 cm-1 region to N-H modes of His-189 in the D2 polypeptide. When His-189 in D2 is changed to a leucine (HL189D2) in PSII, dramatic alterations of both EPR and FT-IR spectra are observed. When imidazole is introduced into HL189D2 samples, results from both EPR and FT-IR spectroscopy argue that imidazole is functionally reconstituted into an accessible pocket and that imidazole acts as a chemical mimic for His-189. Small perturbations of EPR and FT-IR spectra are consistent with access to this pocket in wild-type PSII, as well. Structures of the analogous site in bacterial reaction centers suggest that an accessible pocket, large enough to contain imidazole, is bordered by tyrosine D and His-189 in the D2 polypeptide. These data provide evidence that His-189 in the D2 polypeptide of PSII acts as a proton acceptor for redox-active tyrosine D and that proton transfer to the imidazole ring facilitates the efficient oxidation/reduction of tyrosine D.
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Affiliation(s)
- S Kim
- Department of Biochemistry, College of Biological Sciences, University of Minnesota, St. Paul, MN 55108-1022, USA
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17
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Ma C, Barry BA. Electron paramagnetic resonance characterization of tyrosine radical, M+, in site-directed mutants of photosystem II(t). Biophys J 1996; 71:1961-72. [PMID: 8889170 PMCID: PMC1233662 DOI: 10.1016/s0006-3495(96)79394-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Photosystem II contains two well-characterized tyrosine radicals, D(.) and Z(.). Z is an electron carrier between the primary chlorophyll donor and the manganese catalytic site and is essential for enzymatic function. On the other hand, D forms a stable radical with no known role in oxygen evolution. D(.) and Z(.) give rise to similar, but not identical, room temperature electron paramagnetic resonance (EPR) signals, which can be distinguished by their decay kinetics. A third room temperature EPR signal has also been observed in site-directed mutants in which a nonredox active amino acid is substituted at the D or Z site. This four-line EPR signal has been shown to have a tyrosine origin by isotopic labeling (Boerner and Barry, 1994, J. Biol. Chem. 269:134-137), but such an EPR signal has never before been observed from a tyrosyl radical. The radical giving rise to this third unique signal has been named M+. Here we provide kinetic evidence that this signal arises from a third redox active tyrosine, distinct from tyrosine D and Z, in the photosystem II reaction center. Isotopic labeling and EPR spectroscopy provide evidence that M is a covalently modified tyrosine.
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Affiliation(s)
- C Ma
- Department of Biochemistry, College of Biological Sciences, University of Minnesota, St. Paul 55108, USA
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McKelvy ML, Britt TR, Davis BL, Gillie JK, Lentz LA, Leugers A, Nyquist RA, Putzig CL. Infrared Spectroscopy. Anal Chem 1996. [DOI: 10.1021/a1960003c] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marianne L. McKelvy
- Analytical Sciences Laboratory, The Dow Chemical Company, Michigan Division, Midland, Michigan 48667
| | - Thomas R. Britt
- Analytical Sciences Laboratory, The Dow Chemical Company, Michigan Division, Midland, Michigan 48667
| | - Bradley L. Davis
- Analytical Sciences Laboratory, The Dow Chemical Company, Michigan Division, Midland, Michigan 48667
| | - J. Kevin Gillie
- Analytical Sciences Laboratory, The Dow Chemical Company, Michigan Division, Midland, Michigan 48667
| | - L. Alice Lentz
- Analytical Sciences Laboratory, The Dow Chemical Company, Michigan Division, Midland, Michigan 48667
| | - Anne Leugers
- Analytical Sciences Laboratory, The Dow Chemical Company, Michigan Division, Midland, Michigan 48667
| | - Richard A. Nyquist
- Analytical Sciences Laboratory, The Dow Chemical Company, Michigan Division, Midland, Michigan 48667
| | - Curtis L. Putzig
- Analytical Sciences Laboratory, The Dow Chemical Company, Michigan Division, Midland, Michigan 48667
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Hoganson CW, Lydakis-Simantiris N, Tang XS, Tommos C, Warncke K, Babcock GT, Diner BA, McCracken J, Styring S. A hydrogen-atom abstraction model for the function of YZ in photosynthetic oxygen evolution. PHOTOSYNTHESIS RESEARCH 1995; 46:177-184. [PMID: 24301580 DOI: 10.1007/bf00020428] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/1995] [Accepted: 05/25/1995] [Indexed: 06/02/2023]
Abstract
Recent magnetic-resonance work on YŻ suggests that this species exhibits considerable motional flexibility in its functional site and that its phenol oxygen is not involved in a well-ordered hydrogen-bond interaction (Tang et al., submitted; Tommos et al., in press). Both of these observations are inconsistent with a simple electron-transfer function for this radical in photosynthetic water oxidation. By considering the roles of catalytically active amino acid radicals in other enzymes and recent data on the water-oxidation process in Photosystem II, we rationalize these observations by suggesting that YŻ functions to abstract hydrogen atoms from aquo- and hydroxy-bound managanese ions in the (Mn)4 cluster on each S-state transition. The hydrogen-atom abstraction process may occur either by sequential or concerted kinetic pathways. Within this model, the (Mn)4/YZ center forms a single catalytic center that comprises the Oxygen Evolving Complex in Photosystem II.
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Affiliation(s)
- C W Hoganson
- Department of Chemistry, Michigan State University, 48824, East Lansing, MI, USA
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MacDonald GM, Steenhuis JJ, Barry BA. A difference Fourier transform infrared spectroscopic study of chlorophyll oxidation in hydroxylamine-treated photosystem II. J Biol Chem 1995; 270:8420-8. [PMID: 7721736 DOI: 10.1074/jbc.270.15.8420] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In oxygenic photosynthesis, photosystem II is the chlorophyll-containing reaction center that carries out the light-induced transfer of electrons from water to plastoquinone. Fourier transform infrared spectroscopy can be used to obtain information about the structural changes that accompany electron transfer in photosystem II. The vibrational difference spectrum associated with the reduction of photosystem II acceptor quinones is of interest. Previously, a high concentration of the photosystem II donor, hydroxylamine, has been used to obtain a spectrum attributed to QA- -QA (Berthomieu, C., Nabedryk, E., Mantele, W. and Breton, J. FEBS Lett. (1990) 269, 363). Here, we use electron paramagnetic resonance, Fourier transform infrared spectroscopy, and 15N isotopic labeling to show that the difference infrared spectrum, obtained under these conditions, also exhibits a contribution from the oxidation of chlorophyll.
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Affiliation(s)
- G M MacDonald
- Department of Biochemistry, University of Minnesota, St. Paul 55108, USA
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Affiliation(s)
- B A Barry
- Department of Biochemistry, University of Minnesota, St. Paul 55108, USA
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