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Magdaong NCM, Buhrmaster JC, Faries KM, Liu H, Tira GA, Lindsey JS, Hanson DK, Holten D, Laible PD, Kirmaier C. In Situ, Protein-Mediated Generation of a Photochemically Active Chlorophyll Analogue in a Mutant Bacterial Photosynthetic Reaction Center. Biochemistry 2021; 60:1260-1275. [PMID: 33835797 DOI: 10.1021/acs.biochem.1c00137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
All possible natural amino acids have been substituted for the native LeuL185 positioned near the B-side bacteriopheophytin (HB) in the bacterial reaction center (RC) from Rhodobacter sphaeroides. Additional mutations that enhance electron transfer to the normally inactive B-side cofactors are present. Approximately half of the isolated RCs with Glu at L185 contain a magnesium chlorin (CB) in place of HB. The chlorin is not the common BChl a oxidation product 3-desvinyl-3-acetyl chlorophyll a with a C-C bond in ring D and a C═C bond in ring B but has properties consistent with reversal of these bond orders, giving 17,18-didehydro BChl a. In such RCs, charge-separated state P+CB- forms in ∼5% yield. The other half of the GluL185-containing RCs have a bacteriochlorophyll a (BChl a) denoted βB in place of HB. Residues His, Asp, Asn, and Gln at L185 yield RCs with ≥85% βB in the HB site, while most other amino acids result in RCs that retain HB (≥95%). To the best of our knowledge, neither bacterial RCs that harbor five BChl a molecules and one chlorophyll analogue nor those with six BChl a molecules have been reported previously. The finding that altering the local environment within a cofactor binding site of a transmembrane complex leads to in situ generation of a photoactive chlorin with an unusual ring oxidation pattern suggests new strategies for amino acid control over pigment type at specific sites in photosynthetic proteins.
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Affiliation(s)
- Nikki Cecil M Magdaong
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - James C Buhrmaster
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Kaitlyn M Faries
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Haijun Liu
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Gregory A Tira
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Deborah K Hanson
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Dewey Holten
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Philip D Laible
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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Gangada S, Chakali M, Mandal H, Duvva N, Chitta R, Lingamallu G, Bangal PR. Excitation-dependent electron exchange energy and electron transfer dynamics in a series of covalently tethered N,N-bis(4'-tert-butylbiphenyl-4-yl)aniline - [C 60] fullerene dyads via varying π-conjugated spacers. Phys Chem Chem Phys 2018; 20:21352-21367. [PMID: 30095832 DOI: 10.1039/c8cp03521k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Femtosecond time-resolved fluorescence and transient absorption studies are reported for three newly synthesized covalently linked N,N-bis(4'-tert-butylbiphenyl-4-yl)aniline (BBA) and pyrrolidinofullerenes (C60)-based donor-π conjugated bridge-acceptor dyads (D-B-A) as functions of the bridge length (7.1, 9.5 and 11.2 Å for Dyad-1, Dyad-2 and Dyad-3), dielectric constants of the medium and pump wavelengths. In polar solvent, ultrafast fluorescence quenching (kEET ≥ 2 × 1012 s-1) of the BBA moiety upon excitation of the BBA moiety (320 nm) is observed in the dyads and is assigned to a mechanism involving electron exchange energy transfer (EET) from 1BBA* to C60 followed by electron transfer from BBA to 1C60*. Cohesive rise and decay dynamics of conjugated BBA˙+-C60˙- anion pairs confirm the involvement of a distance independent adiabatic charge-separation (CS) process (kCS ≥ 2.2 × 1011 s-1) with near unity quantum efficiency (φCS ≥ 99.7%) and a distance-dependent non-adiabatic charge-recombination (CR) process [kCR ∼ (1010-108) s-1]. In contrast, excitation of the C60 moiety (λex = 430 to 700 nm) illustrates photoinduced electron transfer from BBA to 1C60*, involving non-adiabatic (diabatic) and distance-dependent CS (kCS in the range of 0.59-1.78 × 1011 s-1) with 98.86-99.6% (Dyad-3-Dyad-1) quantum efficiency and a CR process with kCR values [kCR ∼ (1010-108) s-1] up to three orders greater than kCS of the respective dyads. Both the processes, CS and CR, upon C60 excitation and the CR process upon BBA excitation show distance dependent rate constants with exponential factor β ≤ 0.5 Å-1, and electron transfer is concluded to occur through a covalently linked conjugated π bridge. Global and target analysis of fsTA data reveal the occurrence of two closely lying CS states, thermally hot (CShot) and thermally relaxed (CSeq) states, and two CR processes with two orders of different rate constants. Careful analysis of the kinetic and thermodynamic data allowed us to estimate the total reorganization energy and electronic coupling matrix (V), which decrease exponentially with distance. These novel features of the distance independent adiabatic CS process and the distance-dependent diabatic CR process upon donor excitation are due to extending the π-conjugation between BBA and C60. The demonstrated results may provide a benchmark in the design of light-harvesting molecular devices where ultrafast CS processes and long-lived CS states are essential requirements.
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Affiliation(s)
- Suneel Gangada
- Department of Chemistry, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan - 305817, India.
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Villamaina D, Kelson MMA, Bhosale SV, Vauthey E. Excitation wavelength dependence of the charge separation pathways in tetraporphyrin-naphthalene diimide pentads. Phys Chem Chem Phys 2014; 16:5188-200. [DOI: 10.1039/c3cp54871f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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4
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Yakovlev AG, Khmelnitsky AY, Shuvalov VA. Femtosecond charge separation in dry films of reaction centers of Rhodobacter sphaeroides and Chloroflexus aurantiacus. BIOCHEMISTRY (MOSCOW) 2012; 77:444-55. [DOI: 10.1134/s0006297912050045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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YAKOVLEV ANDREIG, SHKUROPATOVA TATIANAA, VASILIEVA LYUDMILAG, YA. SHKUROPATOV ANATOLI, SHUVALOV VLADIMIRA. WAVE PACKET MOTIONS COUPLED TO ELECTRON TRANSFER IN REACTION CENTERS OF CHLOROFLEXUS AURANTIACUS. J Bioinform Comput Biol 2012; 6:643-66. [DOI: 10.1142/s0219720008003680] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 12/03/2007] [Accepted: 01/04/2008] [Indexed: 11/18/2022]
Abstract
Transient absorption difference spectroscopy with ~20 femtosecond (fs) resolution was applied to study the time and spectral evolution of low-temperature (90 K) absorbance changes in isolated reaction centers (RCs) of Chloroflexus (C.) aurantiacus. In RCs, the composition of the B-branch chromophores is different with respect to that of purple bacterial RCs by occupying the BB binding site of accessory bacteriochlorophyll by bacteriopheophytin molecule (ΦB). It was found that the nuclear wave packet motion induced on the potential energy surface of the excited state of the primary electron donor P* by ~20 fs excitation leads to a coherent formation of the states [Formula: see text] and [Formula: see text] (BA is a bacteriochlorophyll monomer in the A-branch of cofactors). The processes were studied by measuring coherent oscillations in kinetics of the absorbance changes at 900 nm and 940 nm (P* stimulated emission), at 750 nm and 785 nm (ΦB absorption bands), and at 1,020–1028 nm ([Formula: see text] absorption band). In RCs, the immediate bleaching of the P band at 880 nm and the appearance of the stimulated wave packet emission at 900 nm were accompanied (with a small delay of 10–20 fs) by electron transfer from P* to the B-branch with bleaching of the ΦB absorption band at 785 nm due to [Formula: see text] formation. These data are consistent with recent measurements for the mutant HM182L Rb. sphaeroides RCs (Yakovlev et al., Biochim Biophys Acta1757:369–379, 2006). Only at a delay of 120 fs was the electron transfer from P* to the A-branch observed with a development of the [Formula: see text] absorption band at 1028 nm. This development was in phase with the appearance of the P* stimulated emission at 940 nm. The data on the A-branch electron transfer in C. aurantiacus RCs are consistent with those observed in native RCs of Rb. sphaeroides. The mechanism of charge separation in RCs with the modified B-branch pigment composition is discussed in terms of coupling between the nuclear wave packet motion and electron transfer from P* to ΦB and BA primary acceptors in the B-branch and A-branch, respectively.
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Affiliation(s)
- ANDREI G. YAKOVLEV
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119991, Russian Federation
| | - TATIANA A. SHKUROPATOVA
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - LYUDMILA G. VASILIEVA
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| | - ANATOLI YA. SHKUROPATOV
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| | - VLADIMIR A. SHUVALOV
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119991, Russian Federation
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
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Leonova MM, Fufina TY, Vasilieva LG, Shuvalov VA. Structure-function investigations of bacterial photosynthetic reaction centers. BIOCHEMISTRY (MOSCOW) 2012; 76:1465-83. [DOI: 10.1134/s0006297911130074] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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7
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Khatypov RA, Khmelnitskiy AY, Khristin AM, Fufina TY, Vasilieva LG, Shuvalov VA. Primary charge separation within P870* in wild type and heterodimer mutants in femtosecond time domain. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:1392-8. [PMID: 22209778 DOI: 10.1016/j.bbabio.2011.12.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 12/09/2011] [Accepted: 12/14/2011] [Indexed: 10/14/2022]
Abstract
Primary charge separation dynamics in the reaction center (RC) of purple bacterium Rhodobacter sphaeroides and its P870 heterodimer mutants have been studied using femtosecond time-resolved spectroscopy with 20 and 40fs excitation at 870nm at 293K. Absorbance increase in the 1060-1130nm region that is presumably attributed to P(A)(δ+) cation radical molecule as a part of mixed state with a charge transfer character P*(P(A)(δ+)P(B)(δ-)) was found. This state appears at 120-180fs time delay in the wild type RC and even faster in H(L173)L and H(M202)L heterodimer mutants and precedes electron transfer (ET) to B(A) bacteriochlorophyll with absorption band at 1020nm in WT. The formation of the P(A)(δ+)B(A)(δ-) state is a result of the electron transfer from P*(P(A)(δ+)P(B)(δ-)) to the primary electron acceptor B(A) (still mixed with P*) with the apparent time delay of ~1.1ps. Next step of ET is accompanied by the 3-ps appearance of bacteriopheophytin a(-) (H(A)(-)) band at 960nm. The study of the wave packet formation upon 20-fs illumination has shown that the vibration energy of the wave packet promotes reversible overcoming of an energy barrier between two potential energy surfaces P* and P*(P(A)(δ+)B(A)(δ-)) at ~500fs. For longer excitation pulses (40fs) this promotion is absent and tunneling through an energy barrier takes about 3ps. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.
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Affiliation(s)
- R A Khatypov
- Russian Academy of Sciences, Moscow, Russian Federation
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Yakovlev AG, Vasilieva LG, Khmelnitskaya TI, Shkuropatova VA, Shkuropatov AY, Shuvalov VA. Primary electron transfer in reaction centers of YM210L and YM210L/HL168L mutants of Rhodobacter sphaeroides. BIOCHEMISTRY. BIOKHIMIIA 2010; 75:832-40. [PMID: 20673206 DOI: 10.1134/s0006297910070047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The role of tyrosine M210 in charge separation and stabilization of separated charges was studied by analyzing of the femtosecond oscillations in the kinetics of decay of stimulated emission from P* and of a population of the primary charge separated state P(+)B(A)(-) in YM210L and YM210L/HL168L mutant reaction centers (RCs) of Rhodobacter sphaeroides in comparison with those in native Rba. sphaeroides RCs. In the mutant RCs, TyrM210 was replaced by Leu. The HL168L mutation placed the redox potential of the P(+)/P pair 123 mV below that of native RCs, thus creating a theoretical possibility of P(+)B(A)(-) stabilization. Kinetics of P* decay at 940 nm of both mutants show a significant slowing of the primary charge separation reaction in comparison with native RCs. Distinct damped oscillations in these kinetics with main frequency bands in the range of 90-150 cm(-1) reflect mostly nuclear motions inside the dimer P. Formation of a very small absorption band of B(A)(-) at 1020 nm is registered in RCs of both mutants. The formation of the B(A)(-) band is accompanied by damped oscillations with main frequencies from ~10 to ~150 cm(-1). Only a partial stabilization of the P(+)B(A)(-) state is seen in the YM210L/HL168L mutant in the form of a small non-oscillating background of the 1020-nm kinetics. A similar charge stabilization is absent in the YM210L mutant. A model of oscillatory reorientation of the OH-group of TyrM210 in the electric fields of P(+) and B(A)(-) is proposed to explain rapid stabilization of the P(+)B(A)(-) state in native RCs. Small oscillatory components at ~330-380 cm(-1) in the 1020-nm kinetics of native RCs are assumed to reflect this reorientation. We conclude that the absence of TyrM210 probably cannot be compensated by lowering of the P(+)B(A)(-) free energy that is expected for the double YM210L/HL168L mutant. An oscillatory motion of the HOH55 water molecule under the influence of P(+) and B(A)(-) is assumed to be another potential contributor to the mechanism of P(+)B(A)(-) stabilization.
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Affiliation(s)
- A G Yakovlev
- Department of Photobiophysics, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Russia.
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Yang D, Qing Y, Min C. Incorporation of the chlorophyll d-binding light-harvesting protein from Acaryochloris marina and its localization within the photosynthetic apparatus of Synechocystis sp. PCC6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:204-11. [DOI: 10.1016/j.bbabio.2009.10.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 10/11/2009] [Accepted: 10/14/2009] [Indexed: 11/30/2022]
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10
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Mechanism of Charge Separation in Purple Bacterial Reaction Centers. THE PURPLE PHOTOTROPHIC BACTERIA 2009. [DOI: 10.1007/978-1-4020-8815-5_19] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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Jones MR. Structural Plasticity of Reaction Centers from Purple Bacteria. THE PURPLE PHOTOTROPHIC BACTERIA 2009. [DOI: 10.1007/978-1-4020-8815-5_16] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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12
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Saito K, Kikuchi T, Mukai K, Sumi H. Sequential or superexchange mechanism in bridged electron transfer distinguished by dynamics at a bridging molecule. Phys Chem Chem Phys 2009; 11:5290-301. [DOI: 10.1039/b822206a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ivashin N, Larsson S. Trapped Water Molecule in the Charge Separation of a Bacterial Reaction Center. J Phys Chem B 2008; 112:12124-33. [DOI: 10.1021/jp711924f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Nikolai Ivashin
- Institute of Physics, National Academy of Sciences, Nezalezhnasti Avenue 70, 220072 Minsk, Belarus, Department of Physical Chemistry, Chalmers University of Technology, S-41296, Göteborg, Sweden
| | - Sven Larsson
- Institute of Physics, National Academy of Sciences, Nezalezhnasti Avenue 70, 220072 Minsk, Belarus, Department of Physical Chemistry, Chalmers University of Technology, S-41296, Göteborg, Sweden
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Ziolek M, Pawlowicz N, Naskrecki R, Dobek A. Electron transfer in the reaction center of the Rb. sphaeroides R-26 studied by transient absorption. J Phys Chem B 2007; 109:18171-6. [PMID: 16853333 DOI: 10.1021/jp050682i] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electron transfer at the reaction center of the purple photosynthetic bacterium Rb. sphaeroides R-26 was measured at room temperature by the time-resolved transient absorption spectroscopy technique with 200 fs temporal resolution. The absorbance changes characteristic of the excited state of the primary donor and extending over the whole spectral range investigated from 350 nm up to 720 nm appeared after excitation with a laser pulse of about 100 fs duration at 800 nm. The time evolution of the spectra reflected the excitation of bacteriochlorophylls (BChl) M and L and the subsequent transfer of this excitation to the primary electron donor (P), with the time constant shorter than 1 ps. The decay time constant of the excited primary donor P was determined as about 3 ps, and it was faster than the rise of the reduced intermediary acceptor bacteriopheophytin (BPhe(L)). Photoreduction of BPhe(L) and its further reoxidation was clearly observed as an increase in its bleaching band intensity at around 540 nm in about 4 ps and its decrease in about 200 ps. Our findings support the theoretical model assuming the involvement of the intermediate state P(+)BChl- in the so-called "two-step" model. In this model an electron is transferred in a sequence from the excited special pair P* to bacteriochlorophyll, BChl(L), then to bacteriopheophytin, BPhe(L), and further on to quinone, Q(A). The branched charge separation, partially via P and partially via BChl(L), was also observed.
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Affiliation(s)
- Marcin Ziolek
- Center for Ultrafast Laser Spectroscopy, A. Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland
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Chen M, Cai ZL. Theoretical study on the thermodynamic properties of chlorophyll d-peptides coordinating ligand. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:603-9. [PMID: 17306215 DOI: 10.1016/j.bbabio.2007.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 12/26/2006] [Accepted: 01/08/2007] [Indexed: 10/23/2022]
Abstract
The chlorophyll d containing cyanobacterium, Acaryochloris marina has provided a model system for the study of chlorophyll replacement in the function of oxygenic photosynthesis. Chlorophyll d replaces most functions of chlorophyll a in Acaryochloris marina. It not only functions as the major light-harvesting pigment, but also acts as an electron transfer cofactor in the primary charge separation reaction in the two photosystems. The Mg-chlorophyll d-peptide coordinating interaction between the amino acid residues and chlorophylls using the latest semi-empirical PM5 method were examined. It is suggested that chlorophyll d possesses similar coordination ligand properties to chlorophyll a, but chlorophyll b possesses different ligand properties. Compared with other studies involving theoretical correlation and our prior experiments, this study suggests that the chlorophyll a-bound proteins will bind chlorophyll d without difficulty when chlorophyll d is available.
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Affiliation(s)
- Min Chen
- School of Biological Sciences, The University of Sydney, NSW 2006, Australia.
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Kee HL, Laible PD, Bautista JA, Hanson DK, Holten D, Kirmaier C. Determination of the Rate and Yield of B-side Quinone Reduction in Rhodobacter capsulatus Reaction Centers. Biochemistry 2006; 45:7314-22. [PMID: 16752920 DOI: 10.1021/bi060277x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the native purple bacterial reaction center (RC), light-driven charge separation utilizes only the A-side cofactors, with the symmetry related B-side inactive. The process is initiated by electron transfer from the excited primary donor (P*) to the A-side bacteriopheophytin (P* --> P+ H(A)-) in approximately 3 ps. This is followed by electron transfer to the A-side quinone (P+ H(A)- --> P+ Q(A)-) in approximately 200 ps, with an overall quantum yield of approximately 100%. Using nanosecond flash photolysis and RCs from the Rhodobacter capsulatus F(L181)Y/Y(M208)F/L(M212)H mutant (designated YFH), we have probed the decay pathways of the analogous B-side state P+ H(B)-. The rate of the P+ H(B)- --> ground-state charge-recombination process is found to be (3.0 +/- 0.8 ns)(-1), which is much faster than the analogous (10-20 ns)(-1) rate of P+ H(A)- --> ground state. The rate of P+ H(B)- --> P+ Q(B)- electron transfer is determined to be (3.9 +/- 0.9 ns)(-1), which is about a factor of 20 slower than the analogous A-side process P+ H(A)- --> P+ Q(A)-. The yield of P+ H(B)- --> P+ Q(B)- electron-transfer calculated from these rate constants is 44%. This value, when combined with the known 30% yield of P+ H(B)- from P in YFH RCs, gives an overall yield of 13% for B-side charge separation P* --> P+ H(B)- --> P+ Q(B)- in this mutant. We determine essentially the same value (15%) by comparing the P-bleaching amplitude at approximately 1 ms in YFH and wild-type RCs.
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Affiliation(s)
- Hooi Ling Kee
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
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Yakovlev AG, Shkuropatova TA, Vasilieva LG, Shkuropatov AY, Gast P, Shuvalov VA. Vibrational coherence in bacterial reaction centers with genetically modified B-branch pigment composition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:369-79. [PMID: 16829225 DOI: 10.1016/j.bbabio.2006.05.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Revised: 05/10/2006] [Accepted: 05/11/2006] [Indexed: 11/25/2022]
Abstract
Femtosecond absorption difference spectroscopy was applied to study the time and spectral evolution of low-temperature (90 K) absorbance changes in isolated reaction centers (RCs) of the HM182L mutant of Rhodobacter (Rb.) sphaeroides. In this mutant, the composition of the B-branch RC cofactors is modified with respect to that of wild-type RCs by replacing the photochemically inactive BB accessory bacteriochlorophyll (BChl) by a photoreducible bacteriopheophytin molecule (referred to as PhiB). We have examined vibrational coherence within the first 400 fs after excitation of the primary electron donor P with 20-fs pulses at 870 nm by studying the kinetics of absorbance changes at 785 nm (PhiB absorption band), 940 nm (P*-stimulated emission), and 1020 nm (BA- absorption band). The results of the femtosecond measurements are compared with those recently reported for native Rb. sphaeroides R-26 RCs containing an intact BB BChl. At delay times longer than approximately 50 fs (maximum at 120 fs), the mutant RCs exhibit a pronounced BChl radical anion (BA-) absorption band at 1020 nm, which is similar to that observed for Rb. sphaeroides R-26 RCs and represents the formation of the intermediate charge-separated state P+ BA-. Femtosecond oscillations are revealed in the kinetics of the absorption development at 1020 nm and of decay of the P*-stimulated emission at 940 nm, with the oscillatory components of both kinetics displaying a generally synchronous behavior. These data are interpreted in terms of coupling of wave packet-like nuclear motions on the potential energy surface of the P* excited state to the primary electron-transfer reaction P*-->P+ BA- in the A-branch of the RC cofactors. At very early delay times (up to 80 fs), the mutant RCs exhibit a weak absorption decrease around 785 nm that is not observed for Rb. sphaeroides R-26 RCs and can be assigned to a transient bleaching of the Qy ground-state absorption band of the PhiB molecule. In the range of 740-795 nm, encompassing the Qy optical transitions of bacteriopheophytins HA, HB, and PhiB, the absorption difference spectra collected for mutant RCs at 30-50 fs resemble the difference spectrum of the P+ PhiB- charge-separated state previously detected for this mutant in the picosecond time domain (E. Katilius, Z. Katiliene, S. Lin, A.K.W. Taguchi, N.W. Woodbury, J. Phys. Chem., B 106 (2002) 1471-1475). The dynamics of bleaching at 785 nm has a non-monotonous character, showing a single peak with a maximum at 40 fs. Based on these observations, the 785-nm bleaching is speculated to reflect reduction of 1% of PhiB in the B-branch within about 40 fs, which is earlier by approximately 80 fs than the reduction process in the A-branch, both being possibly linked to nuclear wave packet motion in the P* state.
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Affiliation(s)
- Andrei G Yakovlev
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119899, Russian Federation
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Noy D, Moser CC, Dutton PL. Design and engineering of photosynthetic light-harvesting and electron transfer using length, time, and energy scales. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:90-105. [PMID: 16457774 DOI: 10.1016/j.bbabio.2005.11.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2005] [Revised: 11/16/2005] [Accepted: 11/21/2005] [Indexed: 11/20/2022]
Abstract
Decades of research on the physical processes and chemical reaction-pathways in photosynthetic enzymes have resulted in an extensive database of kinetic information. Recently, this database has been augmented by a variety of high and medium resolution crystal structures of key photosynthetic enzymes that now include the two photosystems (PSI and PSII) of oxygenic photosynthetic organisms. Here, we examine the currently available structural and functional information from an engineer's point of view with the long-term goal of reproducing the key features of natural photosystems in de novo designed and custom-built molecular solar energy conversion devices. We find that the basic physics of the transfer processes, namely, the time constraints imposed by the rates of incoming photon flux and the various decay processes allow for a large degree of tolerance in the engineering parameters. Moreover, we find that the requirements to guarantee energy and electron transfer rates that yield high efficiency in natural photosystems are largely met by control of distance between chromophores and redox cofactors. Thus, for projected de novo designed constructions, the control of spatial organization of cofactor molecules within a dense array is initially given priority. Nevertheless, constructions accommodating dense arrays of different cofactors, some well within 1 nm from each other, still presents a significant challenge for protein design.
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Affiliation(s)
- Dror Noy
- Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
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19
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Yakovlev AG, Jones MR, Potter JA, Fyfe PK, Vasilieva LG, Shkuropatov AY, Shuvalov VA. Primary charge separation between P* and BA: Electron-transfer pathways in native and mutant GM203L bacterial reaction centers. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2005.08.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Zinth W, Wachtveitl J. The First Picoseconds in Bacterial Photosynthesis?Ultrafast Electron Transfer for the Efficient Conversion of Light Energy. Chemphyschem 2005; 6:871-80. [PMID: 15884069 DOI: 10.1002/cphc.200400458] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this Minireview, we describe the function of the bacterial reaction centre (RC) as the central photosynthetic energy-conversion unit by ultrafast spectroscopy combined with structural analysis, site-directed mutagenesis, pigment exchange and theoretical modelling. We show that primary energy conversion is a stepwise process in which an electron is transferred via neighbouring chromophores of the RC. A well-defined chromophore arrangement in a rigid protein matrix, combined with optimised energetics of the different electron carriers, allows a highly efficient charge-separation process. The individual molecular reactions at room temperature are well described by conventional electron-transfer theory.
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Affiliation(s)
- Wolfgang Zinth
- Department für Physik, Ludwig-Maximilians-Universität München, Oettingenstr. 67, 80538 München, Germany.
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21
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Sumi H. Uphill Energy Trapping by Reaction Center in Bacterial Photosynthesis. 2. Unistep Charge Separation, Virtually Mediated by Special Pair, by Photoexcitation in Place of Excitation Transfer from the Antenna System. J Phys Chem B 2004. [DOI: 10.1021/jp031341c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hitoshi Sumi
- Institute of Materials Science, University of Tsukuba, Tsukuba, 305-8573 Japan
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22
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Katilius E, Babendure JL, Katiliene Z, Lin S, Taguchi AKW, Woodbury NW. Manipulations of the B-Side Charge-Separated States' Energetics in the Rhodobacter sphaeroides Reaction Center. J Phys Chem B 2003. [DOI: 10.1021/jp035013o] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Evaldas Katilius
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Jennie L. Babendure
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Zivile Katiliene
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Su Lin
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Aileen K. W. Taguchi
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Neal W. Woodbury
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
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23
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Yakovlev AG, Vasilieva LG, Shkuropatov AY, Bolgarina TI, Shkuropatova VA, Shuvalov VA. Mechanism of Charge Separation and Stabilization of Separated Charges in Reaction Centers of Chloroflexus aurantiacus and of YM210W(L) Mutants of Rhodobacter sphaeroides Excited by 20 fs Pulses at 90 K. J Phys Chem A 2003. [DOI: 10.1021/jp0300647] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. G. Yakovlev
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119992, Russia, and Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
| | - L. G. Vasilieva
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119992, Russia, and Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
| | - A. Ya. Shkuropatov
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119992, Russia, and Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
| | - T. I. Bolgarina
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119992, Russia, and Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
| | - V. A. Shkuropatova
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119992, Russia, and Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
| | - V. A. Shuvalov
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119992, Russia, and Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
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24
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Huppmann P, Spörlein S, Bibikova M, Oesterhelt D, Wachtveitl J, Zinth W. Electron Transfer in Reaction Centers of Blastochloris viridis: Photosynthetic Reactions Approximating the Adiabatic Regime. J Phys Chem A 2003. [DOI: 10.1021/jp027845c] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P. Huppmann
- Institut für BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universität, Oettingenstr. 67, D-80538 München, Germany, Institut für Physikalische und Theoretische Chemie, Johann-Wolfgang-Goethe-Universität, Marie-Curie-Str. 11, D-60439 Frankfurt, Germany, and Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Martinsried, Germany
| | - S. Spörlein
- Institut für BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universität, Oettingenstr. 67, D-80538 München, Germany, Institut für Physikalische und Theoretische Chemie, Johann-Wolfgang-Goethe-Universität, Marie-Curie-Str. 11, D-60439 Frankfurt, Germany, and Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Martinsried, Germany
| | - M. Bibikova
- Institut für BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universität, Oettingenstr. 67, D-80538 München, Germany, Institut für Physikalische und Theoretische Chemie, Johann-Wolfgang-Goethe-Universität, Marie-Curie-Str. 11, D-60439 Frankfurt, Germany, and Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Martinsried, Germany
| | - D. Oesterhelt
- Institut für BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universität, Oettingenstr. 67, D-80538 München, Germany, Institut für Physikalische und Theoretische Chemie, Johann-Wolfgang-Goethe-Universität, Marie-Curie-Str. 11, D-60439 Frankfurt, Germany, and Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Martinsried, Germany
| | - J. Wachtveitl
- Institut für BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universität, Oettingenstr. 67, D-80538 München, Germany, Institut für Physikalische und Theoretische Chemie, Johann-Wolfgang-Goethe-Universität, Marie-Curie-Str. 11, D-60439 Frankfurt, Germany, and Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Martinsried, Germany
| | - W. Zinth
- Institut für BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universität, Oettingenstr. 67, D-80538 München, Germany, Institut für Physikalische und Theoretische Chemie, Johann-Wolfgang-Goethe-Universität, Marie-Curie-Str. 11, D-60439 Frankfurt, Germany, and Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Martinsried, Germany
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Sumi H. Uphill Energy Trapping by Reaction Center in Bacterial Photosynthesis: Charge Separation Unistep from Antenna Excitation, Virtually Mediated by Special-Pair Excitation. J Phys Chem B 2002. [DOI: 10.1021/jp021716e] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hitoshi Sumi
- Institute of Materials Science, University of Tsukuba, Tsukuba 305-8573, Japan
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26
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Yakovlev AG, Shkuropatov AY, Shuvalov VA. Nuclear wave packet motion between P* and P(+)B(A)(-) potential surfaces with a subsequent electron transfer to H(A) in bacterial reaction centers at 90 K. Electron transfer pathway. Biochemistry 2002; 41:14019-27. [PMID: 12437359 DOI: 10.1021/bi020250n] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In Rhodobacter sphaeroides R-26 reaction centers (RCs) the nuclear wave packet induced by 25 fs excitation at 90 K moves on the primary electron donor P* potential energy hypersurface with initial frequency at approximately 130 cm(-1) (monitored by stimulated emission measurement). At the long-wavelength side of P* stimulated emission at 935 nm the wave packet is transferred to the surface with P(+)B(A)(-) character at 120, 380, 1.2 fs, etc. delays (monitored by measurement of the primary electron acceptor B(A)(-) band at 1020 nm). However, only beginning from 380 fs delay and later the relative stabilization of the state P(+)B(A)(-) is observed. This is accompanied by the electron transfer to bacteriopheophytin H(A) (monitored by H(A) band measurement at 760 nm). The most active mode of 32 cm(-1) in the electron transfer and its overtones up to the seventh were found in the Fourier transform spectrum of the oscillatory part of the kinetics of the P* stimulated emission and of the P(+)B(A)(-) and P(+)H(A)(-) formation. This mode and its overtones are apparently populated via the 130 cm(-1) vibrational mode. The deuteration of the sample shifts the fundamental frequency (32 cm(-1)) and all overtones by the same factor of approximately 1.3. This mode and its overtones are suppressed by a factor of approximately 4.7 in the dry film of RCs. The results obtained indicate that the 32 cm(-1) mode might be related to a rotation of hydrogen-containing groups (possibly the water molecule) participating in the modulation of the primary electron transfer from P* to B(A)(-) in at least 35% of RCs. The Brookhaven Protein Data Bank (1PRC) displays the water molecule located at the position HOH302 between His M200 (axial ligand for P(B)) and the oxygen of ring V of B(A) which might be a part (approximately 35%) of the molecular pathway for electron transfer from P* to B(A).
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Affiliation(s)
- Andrei G Yakovlev
- Department of Photobiophysics, Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119992, Russia
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27
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Jortner J, Bixon M, Voityuk AA, Rösch N. Superexchange Mediated Charge Hopping in DNA. J Phys Chem A 2002. [DOI: 10.1021/jp014232b] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joshua Jortner
- School of Chemistry, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel, and Institut für Physikalische und Theoretische Chemie, Technische Universität München, 85747 Garching, Germany
| | - M. Bixon
- School of Chemistry, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel, and Institut für Physikalische und Theoretische Chemie, Technische Universität München, 85747 Garching, Germany
| | - Alexander A. Voityuk
- School of Chemistry, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel, and Institut für Physikalische und Theoretische Chemie, Technische Universität München, 85747 Garching, Germany
| | - Notker Rösch
- School of Chemistry, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel, and Institut für Physikalische und Theoretische Chemie, Technische Universität München, 85747 Garching, Germany
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28
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Huppman P, Arlt T, Penzkofer H, Schmidt S, Bibikova M, Dohse B, Oesterhelt D, Wachtveit J, Zinth W. Kinetics, energetics, and electronic coupling of the primary electron transfer reactions in mutated reaction centers of Blastochloris viridis. Biophys J 2002; 82:3186-97. [PMID: 12023243 PMCID: PMC1302108 DOI: 10.1016/s0006-3495(02)75661-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Femtosecond spectroscopy in combination with site-directed mutagenesis has been used to study the dynamics of primary electron transfer in native and 12 mutated reaction centers of Blastochloris (B) (formerly called Rhodopseudomonas) viridis. The decay times of the first excited state P* vary at room temperature between of 0.6 and 50 ps, and at low temperatures between 0.25 and 90 ps. These changes in time constants are discussed within the scope of nonadiabatic electron transfer theory using different models: 1) If the mutation is assumed to predominantly influence the energetics of the primary electron transfer intermediates, the analysis of the room temperature data for the first electron transfer step to the intermediate P(+)B(A)(-) yields a reorganization energy lambda = 600 +/- 200 cm(-1) and a free energy gap Delta G ranging from -600 cm(-1) to 800 cm(-1). However, this analysis fails to describe the temperature dependence of the reaction rates. 2) A more realistic description of the temperature dependence of the primary electron transfer requires different values for the energetics and specific variations of the electronic coupling upon mutation. Apparently the mutations also lead to pronounced changes in the electronic coupling, which may even dominate the change in the reaction rate. One main message of the paper is that a simple relationship between mutation and a change in one reaction parameter cannot be given and that at the very least the electronic coupling is changed upon mutation.
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Affiliation(s)
- P Huppman
- Institut für BioMolekulare Optik, Sektion Physik, Ludwig-Maximilians-Universität, D-80538 München, Germany
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29
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Schenkl S, Spörlein S, Müh F, Witt H, Lubitz W, Zinth W, Wachtveitl J. Selective perturbation of the second electron transfer step in mutant bacterial reaction centers. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1554:36-47. [PMID: 12034469 DOI: 10.1016/s0005-2728(02)00211-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In order to specifically perturb the primary electron acceptor B(A) -- a monomeric bacteriochlorophyll (BChl) a -- involved in bacterial photosynthetic charge separation (CS), the protein environment of B(A) in the reaction center (RC) of Rhodobacter sphaeroides was modified by site-directed mutagenesis. Isolated RCs were characterized by redox titrations, low temperature optical spectroscopy, ENDOR/TRIPLE resonance spectroscopy and femtosecond time-resolved spectroscopy. Two mutations were studied: In the GS(M203) mutant a serine is introduced near the ring E keto group of B(A), while in FY(L146) a phenylalanine near the ring A acetyl group of B(A) is replaced by tyrosine. In all mutations the oxidation potential of the primary electron donor P as well as the electronic structure of both the P(*+) radical cation and the radical anion of the secondary electron acceptor, H(A)(*-), are not significantly altered compared to the wild type (WT), while changes of the optical absorption spectra at 77 K in the BChl Q(X) and Q(Y) regions are observed. The GS(M203) mutation only leads to a minor retardation of the CS reactions at room temperature, whereas for FY(L146) significant deviations from the native electron transfer (ET) rates could be detected: In addition to a faster first (2.9 ps) and a slower second (1 ps) ET step, a new 8-ps time constant was found in the FY(L146) mutant, which can be ascribed to a fraction of RCs with slowed down secondary ET. The results allow us to address the functional role of the acetyl group of B(A) and question the role of the free energy changes as the main determining factor of ET rates in RCs. It is concluded that structural rearrangements alter the electronic coupling between the pigments and thereby influence the rate of fast CS.
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Affiliation(s)
- Selma Schenkl
- Sektion Physik, Ludwig-Maximilians-Universität München, Oettingenstr. 67, 80538 Munich, Germany
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30
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Ivashin N, Larsson S. Vibrational Mechanism for Primary Charge Separation in the Reaction Center of Rhodobacter Sphaeroides. J Phys Chem B 2002. [DOI: 10.1021/jp013431s] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nikolaj Ivashin
- Institute of Molecular and Atomic Physics, National Academy of Sciences, 70 F. Skaryna Avenue, 220072 Minsk, Belarus
| | - Sven Larsson
- Department of Physical Chemistry, Chalmers University of Technology, S-41296 Göteborg, Sweden
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31
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Katilius E, Katiliene Z, Lin S, Taguchi AKW, Woodbury NW. B Side Electron Transfer in a Rhodobacter sphaeroides Reaction Center Mutant in Which the B Side Monomer Bacteriochlorophyll Is Replaced with Bacteriopheophytin: Low-Temperature Study and Energetics of Charge-Separated States. J Phys Chem B 2002. [DOI: 10.1021/jp013265o] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Evaldas Katilius
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Zivile Katiliene
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Su Lin
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Aileen K. W. Taguchi
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
| | - Neal W. Woodbury
- Department of Chemistry and Biochemistry and the Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604
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33
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Sumi H, Kakitani T. Unified Theory on Rates for Electron Transfer Mediated by a Midway Molecule, Bridging between Superexchange and Sequential Processes. J Phys Chem B 2001. [DOI: 10.1021/jp010018b] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hitoshi Sumi
- Institute of Materials Science, University of Tsukuba, Tsukuba, 305-8573, Japan, and Department of Physics, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Toshiaki Kakitani
- Institute of Materials Science, University of Tsukuba, Tsukuba, 305-8573, Japan, and Department of Physics, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan
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