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Khristin AM, Fufina TY, Khatypov RA. Femtosecond Dynamics of the Excited Primary Electron Donor in Reaction Centers of the Purple Bacterium Rhodobacter sphaeroides. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:1313-1324. [PMID: 39218027 DOI: 10.1134/s0006297924070125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 06/03/2024] [Accepted: 06/06/2024] [Indexed: 09/04/2024]
Abstract
Femtosecond transient absorption spectroscopy was used to study the dynamics of the excited primary electron donor in the reaction centers of the purple bacterium Rhodobacter sphaeroides. Using global analysis and the interval method, we found a correlation between the vibrational coherence damping of the excited primary electron donor and the lifetime of the charge-separated state P+BA-, indicating the reversibility of electron transfer to the primary electron acceptor, the BA molecule. In the reaction centers, the signs of superposition of two electronic states of P were found for a delay time of less than 200 fs. It is suggested that the admixture value of the charge transfer state PA+PB- with the excited primary electron donor P* is about 24%. The results obtained are discussed in terms of the two-step electron transfer mechanism.
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Affiliation(s)
- Anton M Khristin
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Tatyana Yu Fufina
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Ravil A Khatypov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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Fufina TY, Selikhanov GK, Gabdulkhakov AG, Vasilieva LG. Properties and Crystal Structure of the Cereibacter sphaeroides Photosynthetic Reaction Center with Double Amino Acid Substitution I(L177)H + F(M197)H. MEMBRANES 2023; 13:157. [PMID: 36837660 PMCID: PMC9964780 DOI: 10.3390/membranes13020157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/19/2023] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
The photosynthetic reaction center of the purple bacterium Cereibacter sphaeroides with two site-directed mutations Ile-L177-His and M197 Phe-His is of double interest. The substitution I(L177)H results in strong binding of a bacteriochlorophyll molecule with L-subunit. The second mutation F(M197)H introduces a new H-bond between the C2-acetyl carbonyl group of the bacteriochlorophyll PB and His-M197, which is known to enhance the stability of the complex. Due to this H-bond, π -electron system of P finds itself connected to an extensive H-bonding network on the periplasmic surface of the complex. The crystal structure of the double mutant reaction center obtained with 2.6 Å resolution allows clarifying consequences of the Ile L177 - His substitution. The value of the P/P+ midpoint potential in the double mutant RC was found to be ~20 mV less than the sum of potentials measured in the two RCs with single mutations I(L177)H and F(M197)H. The protein environment of the BChls PA and BB were found to be similar to that in the RC with single substitution I(L177)H, whereas an altered pattern of the H-bonding networks was found in the vicinity of bacteriochlorophyll PB. The data obtained are consistent with our previous assumption on a correlation between the bulk of the H-bonding network connected with the π-electron system of the primary electron donor P and the value of its oxidation potential.
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Affiliation(s)
- Tatiana Yu. Fufina
- Federal Research Center Pushchino Scientific Center for Biological Research PSCBR, Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, 142290 Pushchino, Russia
| | - Georgii K. Selikhanov
- Federal Research Center Pushchino Scientific Center for Biological Research PSCBR, Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, 142290 Pushchino, Russia
- Institute of Protein Research, Russian Academy of Sciences, Institutskaya Street 4, 142290 Pushchino, Russia
| | - Azat G. Gabdulkhakov
- Institute of Protein Research, Russian Academy of Sciences, Institutskaya Street 4, 142290 Pushchino, Russia
| | - Lyudmila G. Vasilieva
- Federal Research Center Pushchino Scientific Center for Biological Research PSCBR, Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya Street 2, 142290 Pushchino, Russia
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Vasilieva LG, Kaminskaya OP, Yakovlev AG, Shkuropatov AY, Semenov AY, Nadtochenko VA, Krasnovsky AA, Parson WW, Allakhverdiev SI, Govindjee G. In memory of Vladimir Anatolievich Shuvalov (1943-2022): an outstanding biophysicist. PHOTOSYNTHESIS RESEARCH 2022; 154:207-223. [PMID: 36070062 DOI: 10.1007/s11120-022-00932-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
We present here a tribute to one of the foremost biophysicists of our time, Vladimir Anatolievich Shuvalov, who made important contributions in bioenergetics, especially on the primary steps of conversion of light energy into charge-separated states in both anoxygenic and oxygenic photosynthesis. For this, he and his research team exploited pico- and femtosecond transient absorption spectroscopy, photodichroism & circular dichroism spectroscopy, light-induced FTIR (Fourier-transform infrared) spectroscopy, and hole-burning spectroscopy. We remember him for his outstanding leadership and for being a wonderful mentor to many scientists in this area. Reminiscences by many [Suleyman Allakhverdiev (Russia); Robert Blankenship (USA); Richard Cogdell (UK); Arvi Freiberg (Estonia); Govindjee Govindjee (USA); Alexander Krasnovsky, jr, (Russia); William Parson (USA); Andrei Razjivin (Russia); Jian- Ren Shen (Japan); Sergei Shuvalov (Russia); Lyudmilla Vasilieva (Russia); and Andrei Yakovlev (Russia)] have included not only his wonderful personal character, but his outstanding scientific research.
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Affiliation(s)
- Lyudmila G Vasilieva
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Moscow Region, Pushchino, Russian Federation
| | - Olga P Kaminskaya
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Moscow Region, Pushchino, Russian Federation
| | - Andrei G Yakovlev
- A.N. Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119992, Russian Federation
| | - Anatoliy Ya Shkuropatov
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Moscow Region, Pushchino, Russian Federation
| | - Alexey Yu Semenov
- A.N. Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119992, Russian Federation
| | - Victor A Nadtochenko
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Kosygina St. 4, Moscow, 117977, Russian Federation
| | - Alexander A Krasnovsky
- Bach Institute of Biochemistry, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russian Federation
| | - William W Parson
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA.
| | - Suleyman I Allakhverdiev
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Moscow Region, Pushchino, Russian Federation.
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russian Federation.
| | - Govindjee Govindjee
- Department of Biochemistry, Department of Plant Biology and Center of Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 289 Morrill Hall, 505 South Goodwin Avenue, Urbana, IL, 61801, USA.
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Selikhanov G, Fufina T, Guenther S, Meents A, Gabdulkhakov A, Vasilieva L. X-ray structure of the Rhodobacter sphaeroides reaction center with an M197 Phe→His substitution clarifies the properties of the mutant complex. IUCRJ 2022; 9:261-271. [PMID: 35371503 PMCID: PMC8895020 DOI: 10.1107/s2052252521013178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/11/2021] [Indexed: 06/14/2023]
Abstract
The first steps of the global process of photosynthesis take place in specialized membrane pigment-protein complexes called photosynthetic reaction centers (RCs). The RC of the photosynthetic purple bacterium Rhodobacter sphaeroides, a relatively simple analog of the more complexly organized photosystem II in plants, algae and cyanobacteria, serves as a convenient model for studying pigment-protein interactions that affect photochemical processes. In bacterial RCs the bacteriochlorophyll (BChl) dimer P serves as the primary electron donor, and its redox potential is a critical factor in the efficient functioning of the RC. It has previously been shown that the replacement of Phe M197 by His strongly affects the oxidation potential of P (E m P/P+), increasing its value by 125 mV, as well as increasing the thermal stability of RC and its stability in response to external pressure. The crystal structures of F(M197)H RC at high resolution obtained using various techniques presented in this report clarify the optical and electrochemical properties of the primary electron donor and the increased resistance of the mutant complex to denaturation. The electron-density maps are consistent with the donation of a hydrogen bond from the imidazole group of His M197 to the C2-acetyl carbonyl group of BChl PB. The formation of this hydrogen bond leads to a considerable out-of-plane rotation of the acetyl carbonyl group and results in a 1.2 Å shift of the O atom of this group relative to the wild-type structure. Besides, the distance between BChl PA and PB in the area of pyrrole ring I was found to be increased by up to 0.17 Å. These structural changes are discussed in association with the spectral properties of BChl dimer P. The electron-density maps strongly suggest that the imidazole group of His M197 accepts another hydrogen bond from the nearest water molecule, which in turn appears to form two more hydrogen bonds to Asn M195 and Asp L155. As a result of the F(M197)H mutation, BChl PB finds itself connected to the extensive hydrogen-bonding network that pre-existed in wild-type RC. Dissimilarities in the two hydrogen-bonding networks near the M197 and L168 sites may account for the different changes of the E m P/P+ in F(M197)H and H(L168)F RCs. The involvement of His M197 in the hydrogen-bonding network also appears to be related to stabilization of the F(M197)H RC structure. Analysis of the experimental data presented here and of the data available in the literature points to the fact that the hydrogen-bonding networks in the vicinity of BChl dimer P may play an important role in fine-tuning the redox properties of the primary electron donor.
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Affiliation(s)
- Georgii Selikhanov
- Group of Structural Studies of Macromolecular Complexes, Institute of Protein Research, Russian Academy of Sciences, Institutskaya 4, Pushchino 142290, Moscow Region, Russian Federation
- Federal Research Center Pushchino Scientific Center for Biological Research PSCBR, Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya 2, Pushchino 142290, Moscow Region, Russian Federation
| | - Tatiana Fufina
- Federal Research Center Pushchino Scientific Center for Biological Research PSCBR, Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya 2, Pushchino 142290, Moscow Region, Russian Federation
| | - Sebastian Guenther
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Alke Meents
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Azat Gabdulkhakov
- Group of Structural Studies of Macromolecular Complexes, Institute of Protein Research, Russian Academy of Sciences, Institutskaya 4, Pushchino 142290, Moscow Region, Russian Federation
| | - Lyudmila Vasilieva
- Federal Research Center Pushchino Scientific Center for Biological Research PSCBR, Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya 2, Pushchino 142290, Moscow Region, Russian Federation
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Amoruso G, Liu J, Polak DW, Tiwari K, Jones MR, Oliver TAA. High-Efficiency Excitation Energy Transfer in Biohybrid Quantum Dot-Bacterial Reaction Center Nanoconjugates. J Phys Chem Lett 2021; 12:5448-5455. [PMID: 34081477 DOI: 10.1021/acs.jpclett.1c01407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Reaction centers (RCs) are the pivotal component of natural photosystems, converting solar energy into the potential difference between separated electrons and holes that is used to power much of biology. RCs from anoxygenic purple photosynthetic bacteria such as Rhodobacter sphaeroides only weakly absorb much of the visible region of the solar spectrum, which limits their overall light-harvesting capacity. For in vitro applications such as biohybrid photodevices, this deficiency can be addressed by effectively coupling RCs with synthetic light-harvesting materials. Here, we studied the time scale and efficiency of Förster resonance energy transfer (FRET) in a nanoconjugate assembled from a synthetic quantum dot (QD) antenna and a tailored RC engineered to be fluorescent. Time-correlated single-photon counting spectroscopy of biohybrid conjugates enabled the direct determination of FRET from QDs to attached RCs on a time scale of 26.6 ± 0.1 ns and with a high efficiency of 0.75 ± 0.01.
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Affiliation(s)
- Giordano Amoruso
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Juntai Liu
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K
| | - Daniel W Polak
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Kavita Tiwari
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, U.K
| | - Michael R Jones
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, U.K
| | - Thomas A A Oliver
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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Khmelnitskiy A, Williams JC, Allen JP, Jankowiak R. Influence of Hydrogen Bonds on the Electron-Phonon Coupling Strength/Marker Mode Structure and Charge Separation Rates in Reaction Centers from Rhodobacter sphaeroides. J Phys Chem B 2019; 123:8717-8726. [PMID: 31539255 DOI: 10.1021/acs.jpcb.9b08388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Low-temperature persistent and transient hole-burning (HB) spectra are presented for the triple hydrogen-bonded L131LH + M160LH + M197FH mutant of Rhodobacter sphaeroides. These spectra expose the heterogeneous nature of the P-, B-, and H-bands, consistent with a distribution of electron transfer (ET) times and excitation energy transfer (EET) rates. Transient P+QA- holes are observed for fast (tens of picoseconds or faster) ET times and reveal strong coupling to phonons and marker mode(s), while the persistent holes are bleached in a fraction of reaction centers with long-lived excited states characterized by much weaker electron-phonon coupling. Exposed differences in electron-phonon coupling strength, as well as a different coupling to the marker mode(s), appear to affect the ET times. Both resonantly and nonresonantly burned persistent HB spectra show weak blue- (∼150 cm-1) and large, red-shifted (∼300 cm-1) antiholes of the P band. Slower EET times from the H- and B-bands to the special pair dimer provide new insight on the influence of hydrogen bonds on mutation-induced heterogeneity.
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Affiliation(s)
| | - JoAnn C Williams
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
| | - James P Allen
- School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287 , United States
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Milanovsky GE, Shuvalov VA, Semenov AY, Cherepanov DA. Elastic Vibrations in the Photosynthetic Bacterial Reaction Center Coupled to the Primary Charge Separation: Implications from Molecular Dynamics Simulations and Stochastic Langevin Approach. J Phys Chem B 2015; 119:13656-67. [PMID: 26148224 DOI: 10.1021/acs.jpcb.5b03036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Primary electron transfer reactions in the bacterial reaction center are difficult for theoretical explication: the reaction kinetics, almost unalterable over a wide range of temperature and free energy changes, revealed oscillatory features observed initially by Shuvalov and coauthors (1997, 2002). Here the reaction mechanism was studied by molecular dynamics and analyzed within a phenomenological Langevin approach. The spectral function of polarization around the bacteriochlorophyll special pair PLPM and the dielectric response upon the formation of PL(+)PM(-) dipole within the special pair were calculated. The system response was approximated by Langevin oscillators; the respective frequencies, friction, and energy coupling coefficients were determined. The protein dynamics around PL and PM were distinctly asymmetric. The polarization around PL included slow modes with the frequency 30-80 cm(-1) and the total amplitude of 130 mV. Two main low-frequency modes of protein response around PM had frequencies of 95 and 155 cm(-1) and the total amplitude of 30 mV. In addition, a slowly damping mode with the frequency of 118 cm(-1) and the damping time >1.1 ps was coupled to the formation of PL(+)PM(-) dipole. It was attributed to elastic vibrations of α-helices in the vicinity of PLPM. The proposed trapping of P excitation energy in the form of the elastic vibrations can rationalize the observed properties of the primary electron transfer reactions, namely, the unusual temperature and ΔG dependences, the oscillating phenomena in kinetics, and the asymmetry of the charge separation reactions.
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Affiliation(s)
- Georgy E Milanovsky
- A. N. Belozersky Institute of Physical-Chemical Biology, Moscow State University , Leninskiye Gory, 119992 Moscow, Russia
| | - Vladimir A Shuvalov
- A. N. Belozersky Institute of Physical-Chemical Biology, Moscow State University , Leninskiye Gory, 119992 Moscow, Russia.,N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences , Kosygina st., 4, 117977 Moscow, Russia
| | - Alexey Yu Semenov
- A. N. Belozersky Institute of Physical-Chemical Biology, Moscow State University , Leninskiye Gory, 119992 Moscow, Russia.,N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences , Kosygina st., 4, 117977 Moscow, Russia
| | - Dmitry A Cherepanov
- A. N. Belozersky Institute of Physical-Chemical Biology, Moscow State University , Leninskiye Gory, 119992 Moscow, Russia.,A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences , 31, Leninsky Prospect, 119071 Moscow, Russia
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