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Interaction of the Fluorophenyl Analog of Retinal with Proteorhodopsin from Exiguobacterium sibiricum. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2022. [DOI: 10.1134/s1068162022060073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Abstract—
We have developed an alternative method for the synthesis of an analog of natural retinal, which contains the p-fluorophenyl fragment instead of the trimethylcyclohexene ring. The proposed scheme for the synthesis of the target all-E-isomer of the target retinoid consists of using C5-phosphonate that contains the terminal nitrile group under Horner–Emmons reaction conditions. It has been shown that this scheme is more efficient and provides a higher total yield of the target product than the previously described variant. The procedure has been developed for the preparation of an analog of microbial proteorhodopsin ESRh from Exiguobacterium sibiricum, which contains a modified chromophore. It has been found that, as in the case of bacterioopsin from Halobacterium salinarum, the replacement of the trimethylcyclohexene ring in the natural chromophore by the p-fluorophenyl fragment does not prevent the formation of the artificial pigment F-Phe-ESRh from proteorhodopsin ESRh, which preserves the cycle of photochemical reactions. Certain differences have been found between the properties of native recombinant ESRh and its analog F-Phe-ESRh including a shift in the absorption maximum to the short-wavelength region, the formation of M intermediate at lower pH values, the presence of “long-lived M,” and a general slowdown in the photocycle. The reduced stability of the resulting proteorhodopsin analog F-Phe-ESRh to prolonged exposure to visible light has been also demonstrated.
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Phycoerythrin Association with Photosystem II in the Cryptophyte Alga Rhodomonas salina. BIOCHEMISTRY (MOSCOW) 2020; 85:679-688. [PMID: 32586231 DOI: 10.1134/s000629792006005x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
# Deceased. Cryptophyte algae belong to a special group of oxygenic photosynthetic organisms containing pigment combination unique for plastids - phycobiliproteins and chlorophyll a/c-containing antenna. Despite the progress in investigation of morphological and ecological features, as well as genome-based systematics of cryptophytes, their photosynthetic apparatus remains poorly understood. The ratio of the photosystems (PS)s I and II is unknown and information on participation of the two antennal complexes in functions of the two photosystems is inconsistent. In the present work we demonstrated for the first time that the cryptophyte alga Rhodomonas salina had the PSI to PSII ratio in thylakoid membranes equal to 1 : 4, whereas this ratio in cyanobacteria and higher plants was known to be 3 : 1 and 1 : 1, respectively. Furthermore, it was established that contrary to the case of cyanobacteria the phycobiliprotein antenna represented by phycoerythrin-545 (PE-545) in R. salina was associated only with the PSII, which indicated specific spatial organization of these protein pigments within the thylakoids that did not facilitate interaction with the PSI.
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Photophysical Properties of Upconverting Nanoparticle-Phthalocyanine Complexes. BIOCHEMISTRY. BIOKHIMIIA 2019; 84:911-922. [PMID: 31522673 DOI: 10.1134/s0006297919080078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Interaction between upconverting nanoparticles and aluminum octacarboxyphthalocyanine was studied. The efficiency of non-radiative energy transfer from the nanoparticles to phthalocyanine increased with the number of phthalocyanine molecules adsorbed on the nanoparticle, but only up to a certain limit. Further increase in the phthalocyanine concentration resulted in a decrease of its sensitized fluorescence due to the dimerization of dye molecules on the nanoparticle surface. When subjected to infrared irradiation, phthalocyanine molecules in the hybrid complex generated singlet oxygen. The observed effects are of interest in regard to the targeted search for new components of efficient third-generation hybrid photosensitizers.
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Fusion with an albumin-binding domain improves pharmacokinetics of an αvβ3-integrin binding fibronectin scaffold protein. Biotechnol Appl Biochem 2019; 66:617-625. [PMID: 31140614 DOI: 10.1002/bab.1762] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 04/29/2019] [Indexed: 12/21/2022]
Abstract
Fusion with an albumin-binding domain (ABD) of streptococcal protein G represents a popular approach for half-life extension of small protein therapeutics in the organism. To increase the circulation time of engineered αvβ3-integrin-binding protein (JCL) based on the 10th human fibronectin type III domain (10 Fn3), we have constructed several fusions with ABD with different orientations of the partner proteins and linker length. The recombinant proteins were expressed in Escherichia coli cells and purified by nickel-affinity chromatography. All fusion proteins bound human serum albumin (HSA) in ELISA assay; however, fusions with longer linkers demonstrated better performance. Interaction of ABD-L15 -JCL and JCL-L14 -ABD with HSA was confirmed by analytical size exclusion chromatography and pull-down assays. Surprisingly, the thermal stability of ABD-L15 -JCL was dramatically decreased in comparison with JCL and JCL-L14 -ABD proteins. Pharmacokinetic studies revealed that JCL-L14 -ABD circulated in murine blood about 10 times longer than ABD-L15 -JCL and 960 times longer than JCL. Biodistribution studies of JCL-L14 -ABD in mice revealed its increased level in blood and a decreased accumulation in liver and kidneys in comparison with JCL. Obtained results demonstrate the utility of the fusion with ABD for half-life extension of the binding proteins based on 10 Fn3.
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Formation of an Efficient Energy Transfer Complex between Quantum Dots and Exiguobacterium sibiricum Retinal Protein via the Histidine-Cysteine Anchor. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2019. [DOI: 10.1134/s1068162018050114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Intramolecular Mobility Affects the Energy Migration from Quantum Dots to Reaction Centers of Photosynthesizing Bacterium Rb. sphaeroides. DOKL BIOCHEM BIOPHYS 2019; 484:21-24. [DOI: 10.1134/s160767291901006x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Indexed: 11/23/2022]
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Relaxation processes accompanying electron stabilization in the quinone acceptor part of Rb. sphaeroides reaction centers. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2018; 189:145-151. [PMID: 30347352 DOI: 10.1016/j.jphotobiol.2018.10.005] [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: 07/23/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 06/08/2023]
Abstract
The temperature dependence of the dark recombination rate in photooxidized bacteriochlorophyll (P) and photoreduced quinone acceptors (ubiquinones) QA and QB of photosynthetic reaction centers of purple bacteria Rhodobacter sphaeroides (Rb. sphaeroides) was studied. Photoinduced changes in the absorption were detected in the Qx absorption band of photooxidized bacteriochlorophyll at 600 nm and in the bands corresponding to the redox changes of ubiquinones at 335 and 420-450 nm. Kinetic analysis was used to evaluate the activation energy and the characteristic time of the transient process of relaxation accompanying electron stabilization at the final quinone acceptor. A comparative study of the kinetics of oxidation-reduction reactions of photoactive bacteriochlorophyll RC purple bacteria and quinone acceptors in their individual absorption bands is an informative approach to studying the mechanisms of this stabilization. The analysis of the revealed kinetic differences makes it possible to estimate the activation energy and the characteristic times of the transition relaxation processes associated with the stabilization of the electron in the quinone acceptor part of RC. Purple bacterial reaction centers have fundamental similarities with PSII reaction centers. Such a similarity represents evolutional closeness between the two types of RC. So it is possible that the photoinduced charge separation in PSII RC, as well as in purple bacteria RC, is also accompanied by definite conformational changes. The possible role of hydrogen bonds of surrounding protein in the relaxation processes accompanying the electron transfer to quinone acceptors is discussed.
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The Efficiency of Energy Transfer from Quantum Dots to Photosynthetic Reaction Centers of Rhodobacter sphaeroides in the Temperature Range of 100–310 K. Biophysics (Nagoya-shi) 2018. [DOI: 10.1134/s0006350918060180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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9
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Influence of trehalose on high-temperature stability of the photosynthetic reaction centers. DOKL BIOCHEM BIOPHYS 2018; 477:368-371. [PMID: 29297127 DOI: 10.1134/s1607672917060072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Indexed: 11/23/2022]
Abstract
The effect of heating at 65°C for 20 min on the absorption spectra and kinetics of the dark recombination of charges separated between photoactive bacteriochlorophyll and quinone acceptors was studied in dry films of bacterial photosynthetic reaction centers (RCs), RC films in polyvinyl alcohol, and trehalose. A pronounced protective effect of trehalose against pheophytinizaiton of molecules bacteriochlorophylls in RC structure and in maintaining their higher photochemical activity was found.
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The Effects of ultraviolet irradiation on hybrid films of photosynthetic reaction centers and quantum dots in various organic matrices. Biophysics (Nagoya-shi) 2017. [DOI: 10.1134/s0006350917050128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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11
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The influence of dipyridamole and its derivatives on the membrane energization state of Rhodobacter sphaeroides bacterial chromatophores. Biophysics (Nagoya-shi) 2017. [DOI: 10.1134/s0006350917050153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Excitation energy transfer from the bacteriochlorophyll Soret band to carotenoids in the LH2 light-harvesting complex from Ectothiorhodospira haloalkaliphila is negligible. PHOTOSYNTHESIS RESEARCH 2017; 133:289-295. [PMID: 28205063 DOI: 10.1007/s11120-017-0341-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/18/2017] [Indexed: 06/06/2023]
Abstract
Pathways of intramolecular conversion and intermolecular electronic excitation energy transfer (EET) in the photosynthetic apparatus of purple bacteria remain subject to debate. Here we experimentally tested the possibility of EET from the bacteriochlorophyll (BChl) Soret band to the singlet S2 level of carotenoids using femtosecond pump-probe measurements and steady-state fluorescence excitation and absorption measurements in the near-ultraviolet and visible spectral ranges. The efficiency of EET from the Soret band of BChl to S2 of the carotenoids in light-harvesting complex LH2 from the purple bacterium Ectothiorhodospira haloalkaliphila appeared not to exceed a few percent.
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A comparison of the temperature dependence of charge recombination in the ion-radical pair P870+QA - and tryptophan fluorescence in the photosynthetic reaction centers of Rhodobacter sphaeroides. Biophysics (Nagoya-shi) 2017. [DOI: 10.1134/s0006350916060191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Functions of chromophore-containing domain in the large linker LCM- polypeptide of phycobilisome. DOKL BIOCHEM BIOPHYS 2017; 471:403-406. [DOI: 10.1134/s1607672916060077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Indexed: 11/23/2022]
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15
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Investigation of stability of photosynthetic reaction center and quantum dot hybrid films. BIOCHEMISTRY (MOSCOW) 2016; 81:58-63. [DOI: 10.1134/s0006297916010065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Energy transfer pathways among phycobilin chromophores and fluorescence emission spectra of the phycobilisome core at 293 and 77 K. DOKL BIOCHEM BIOPHYS 2016; 465:401-5. [PMID: 26728735 DOI: 10.1134/s1607672915060149] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Indexed: 11/23/2022]
Abstract
Energy transfer pathways between phycobiliproteins chromophores in the phycobilisome (PBS) core of the cyanobacterium Synechocystis sp. PCC 6803 were investigated. The computer 3D model of the PBS core with determination of chromophore to chromophore distance was created. Our kinetic equations based on this model allowed us to describe the relative intensities of the fluorescence emission of the short(peaked at 665 nm) and long-wavelength (peaked at 680 nm) chromophores in the PBS core at low and room temperatures. The difference of emissions of the PBS core at 77 and 293 K are due to the back energy transfer, which is observed at room temperature and is negligible at 77 K.
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ESR — A retinal protein with unusual properties from Exiguobacterium sibiricum. BIOCHEMISTRY (MOSCOW) 2015; 80:688-700. [DOI: 10.1134/s000629791506005x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Mechanisms of anomalous temperature dependence of the recombination of the photoseparated charges between bacteriochlorophyll and primary quinone in Rb. sphaeroides: The role of RC hydrogen bonds. DOKL BIOCHEM BIOPHYS 2015; 459:199-203. [PMID: 25559979 DOI: 10.1134/s1607672914060052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Indexed: 11/23/2022]
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19
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Properties of hybrid hybrid complexes composed of photosynthetic reaction centers from the purple bacterium Rhodobacter sphaeroides and quantum dots in lecithin liposomes. BIOCHEMISTRY (MOSCOW) 2014; 79:1183-91. [DOI: 10.1134/s0006297914110054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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20
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Fluorescent fusion proteins derived from the tenth human fibronectin domain. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2014. [DOI: 10.1134/s1068162014030121] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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[Fluorescent fusion proteins with 10th human fibronectin domain]. BIOORGANICHESKAIA KHIMIIA 2014; 40:405-13. [PMID: 25898750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In the current paper we describe a new type of hybrid molecules including red fluorescent protein mCherry and 10th type III human fibronectin domain (10Fn3) - one of the alternative scaffold proteins which can be used for the construction of antibody mimics with various binding specificity. We have constructed different gene variants encoding for the hybrid fluorescent protein and studied their expression in Escherichia coli cells. It was shown that N-terminal position of mCherry and modification of its N-terminal amino acid sequence promotes efficientbacterial expression of the hybrid protein in the soluble form. On the basis of the proposed construction we have obtained the hybrid fluorescent protein ChIBF, containing alphaVbeta3-integrin binding vari- ant of 10Fn3, and demonstrated the possibility of its utilization for the visualization of alphaVbeta3-integrin at the surface of MDCK epithelial cells by confocal microscopy.
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The spectral-kinetic indicators of relaxation processes following the electron stabilization into the acceptor compartment of photosynthetic RCs of bacteria. DOKL BIOCHEM BIOPHYS 2014; 455:49-52. [PMID: 24795098 DOI: 10.1134/s1607672914020021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Indexed: 11/23/2022]
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23
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Photophysical properties of hybrid complexes of quantum dots and reaction centers of purple photosynthetic bacteria Rhodobacter sphaeroides adsorbed on crystalline mesoporous TiO2 films. ACTA ACUST UNITED AC 2013. [DOI: 10.1134/s1995078013040095] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Experimental proof of optimality of interfacing of chlorosome BChl c and membrane BChl a subantennae in superantenna of photosynthetic green bacteria from the oscillochloridaceae family. DOKL BIOCHEM BIOPHYS 2012; 444:154-7. [PMID: 22772999 DOI: 10.1134/s1607672912030088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Indexed: 11/23/2022]
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25
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Photochemical properties of photosystem 1 immobilized in a mesoporous semiconductor matrix. HIGH ENERGY CHEMISTRY 2012. [DOI: 10.1134/s0018143912030095] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Predicted bacteriorhodopsin from Exiguobacterium sibiricum is a functional proton pump. FEBS Lett 2010; 584:4193-6. [PMID: 20831870 DOI: 10.1016/j.febslet.2010.09.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 08/16/2010] [Accepted: 09/01/2010] [Indexed: 10/19/2022]
Abstract
The predicted Exigobacterium sibiricum bacterirhodopsin gene was amplified from an ancient Siberian permafrost sample. The protein bacteriorhodopsin from Exiguobacterium sibiricum (ESR) encoded by this gene was expressed in Escherichia coli membrane. ESR bound all-trans-retinal and displayed an absorbance maximum at 534nm without dark adaptation. The ESR photocycle is characterized by fast formation of an M intermediate and the presence of a significant amount of an O intermediate. Proteoliposomes with ESR incorporated transport protons in an outward direction leading to medium acidification. Proton uptake at the cytoplasmic surface of these organelles precedes proton release and coincides with M decay/O rise of the ESR.
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Influence of carbon nanotubes on chlorophyll fluorescence parameters of green algae Chlamydomonas reinhardtii. ACTA ACUST UNITED AC 2010. [DOI: 10.1134/s199507801005006x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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28
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The influence of alkylhydroxybenzenes on electron stabilization processes in the quinone acceptor portion of the reaction centers of the bacterium Rhodobacter sphaeroides. Microbiology (Reading) 2010. [DOI: 10.1134/s0026261710020190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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29
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Biotesting the biological effects of single-wall carbon nanotubes using bioluminescent bacteria test-system. ACTA ACUST UNITED AC 2010. [DOI: 10.1134/s1995078009110159] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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30
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Reduction of photosystem I reaction center by recombinant DrgA protein in isolated thylakoid membranes of the cyanobacterium Synechocystis sp. PCC 6803. BIOCHEMISTRY (MOSCOW) 2009; 74:1080-7. [DOI: 10.1134/s0006297909100034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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31
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Kinetics of recombination of photoseparated charges in Rhodobacter sphaeroides reaction centers analyzed by relaxation rate constant distribution. Biophysics (Nagoya-shi) 2009. [DOI: 10.1134/s0006350909030051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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32
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[The analysis of kinetics of recombination of photodivided charges in the Rhodobacter sphaeroides photosynthetic reaction centers using relaxation time constant distribution method]. BIOFIZIKA 2009; 54:425-433. [PMID: 19569501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The kinetics of dark recombination of charges photodivided between the bacteriochlorophyll dimer (P) and the quinone acceptors of the photosynthetic reaction centers (RCs) of Rhodobacter sphaeroides has been studied. The electron transfer between P and the quinone acceptors of times of light activation from 1 to 60 s was investigated. The relaxation time constant distribution was computed from experimental kinetic curves of charge recombination using an original method developed by the authors. In this method, relaxation curves are approximated by a set of Gaussian-like peaks in the time domain that correspond to different conformational substates of reaction centers. As the time of photoactivation increases, some peaks shift toward larger relaxation times. A bifurcation of the peaks was observed for the activation times from 20 to 30 s. The phenomenon is interpreted as evidence of the conformational transition induced by separated charges in the structure of reaction centers.
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Photosynthetic activity and components of the electron transport chain in the aerobic bacteriochlorophyll a-containing bacterium Roseinatronobacter thiooxidans. Microbiology (Reading) 2009. [DOI: 10.1134/s0026261709010020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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34
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[Photosynthetic activity and components of the electron transport chain in the aerobic bacteriochlorophyll A-containing bacterium Roseinatronobacter thiooxidans]. MIKROBIOLOGIIA 2009; 78:12-21. [PMID: 19334593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Bioenergetics of the aerobic bacteriochlorophyll a-containing (BCl a) bacterium (ABC bacterium) Roseinatronobacter thiooxidans is a combination of photosynthesis, oxygen respiration, and oxidation of sulfur compounds under alkaliphilic conditions. The photosynthetic activity of Rna. thiooxidans cells was established by the photoinhibition of cell respiration and reversible photobleaching discoloration of the BCl a of reaction centers (RC), connected by the chain of electron transfer with cytochrome c551 oxidation. The species under study, like many purple bacteria and some of the known ABC bacteria, possesses a light-harvesting pigment-protein (LHI) complex with the average number of 30 molecules of antenna BCl a per one photosynthetic RC. Under microaerobic growth conditions, the cells contained bc1 complex and two terminal oxidases: cbb3-cytochrome oxidase and the alternative cytochrome oxidase of the a3 type. Besides, Rna. thiooxidans was shown to have several different soluble low- and high-potential cytochromes c, probably associated with the ability of utilizing sulfur compounds as additional electron donors.
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Nanophotobiocatalysts based on mesoporous titanium dioxide films conjugated with enzymes and photosynthetic reaction centers of bacteria. HIGH ENERGY CHEMISTRY 2008. [DOI: 10.1134/s0018143908070291] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Electron phototransfer between photosynthetic reaction centers of the bacteria Rhodobacter sphaeroides and semiconductor mesoporous tiO2 films. DOKL BIOCHEM BIOPHYS 2007; 415:211-6. [PMID: 17933338 DOI: 10.1134/s1607672907040138] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Grafting of polylysine with polyethylenoxide prevents demixing of O-pyromellitylgramicidin in lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:1685-95. [PMID: 16901462 DOI: 10.1016/j.bbamem.2006.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Revised: 05/19/2006] [Accepted: 06/06/2006] [Indexed: 01/24/2023]
Abstract
Both natural and synthetic polycations can induce demixing of negatively charged components in artificial and possibly in natural membranes. This process can result in formation of clusters (binding of several components to a polycation chain) and/or domains (aggregation of clusters and formation of a separate phase enriched in some particular component). In order to distinguish between these two phenomena, a model lipid membrane system containing ion channels, formed by a negatively charged peptide, O-pyromellitylgramicidin, and polycations of different structures was used. Microelectrophoresis of liposomes, changes in boundary potential of planar bilayers, the shape of compression curves and potentials of lipid and lipid/peptide monolayers were used to monitor the electrostatic factors in polymer adsorption to the membrane and peptide-polymer interactions. The synthesized PEO-grafted polylysine, PLL-PEO20000, did not induce peptide demixing monitored by stabilization of the gramicidin channels, in contrast to parent polylysine (PLL). Both polymers were shown to bind effectively to negatively charged liposomes and lipid monolayers, suggesting that the ineffectiveness of PLL-PEO20000 was not due to reduction of its binding. It was hypothesized that PLL-PEO20000 could not induce domain formation due to steric hindrance of long PEO chains preventing lateral fusion of clusters. Another copolymer, PLL-PEO4000, having four PEO chains of 4000 Da, exhibited intermediate effect between PLL and PLL-PEO20000, which shows the importance of the copolymer architecture for the effect on the lateral distribution of OPg channels. The model system can be relevant to regulation of lateral organization of ion channels and other components in natural membrane systems.
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Photochemical properties of a bacteriorhodopsin analog with 13-demethyl-13-trifluoromethyl retinal. Biophysics (Nagoya-shi) 2006. [DOI: 10.1134/s0006350906030092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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39
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[Photochemical properties of a bacteriorhodopsin analogue containing 13-desmethyl-13-(trifluoromethyl)retinal]. BIOFIZIKA 2006; 51:446-53. [PMID: 16808343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
It was shown that the substitution of the CF3 group in the structure of retinal for the methyl group in the position C-13 causes not only a decrease in the affinity of the proton to the nitrogen atom in the Schiff base (pK approximately 8.4) but also considerably changes the photochemical properties of the bacteriorhodopsin analogue. At pH > 6.5, the rate of the Schiff base reprotonation during M decay depends on the concentration of protons in medium. In the photocycle of the "yellow" M-like form with the deprotonated Schiff base, the long-wavelenght product absorbing at 625 nm is formed, which has a similar pH dependence of decay kinetics. Both processes had also similar activation energies (about 15 +/- 1 kCal/mol). The conclusion was made that, in both cases, a proton transfer from water medium through the donor part of the channel accordingly up to the Schiff base and Asp96 takes place. In this analogue, however, the structure of water molecules necessary for the stabilization of the proton on the Schiff base is broken. As a result, the dehydration of the preparation gives rise to a fraction of M-like form of bacteriorhodopsin with the deprotonated Schiff base.
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On the Mechanisms of Photodynamic Effect of Sensitizers and Improvement of Methods of Their Primary Selection for Photodynamic Antimicrobial Therapy. DOKL BIOCHEM BIOPHYS 2005; 404:363-7. [PMID: 16392758 DOI: 10.1007/s10628-005-0115-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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[A comparative study of the fluorescence properties of the chlorosomal antenna of the green bacterium from the family Oscillochloridaceae and the members from two other families of green bacteria]. BIOFIZIKA 2005; 50:271-6. [PMID: 15856984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The fluorescence properties of bacteriochlorophylls (BChl) of the chlorosomal light-harvesting antenna of Oscillochloris trichoides (strain DG-6) from a new family of green filamentous bacteria Oscillochloridaceae were investigated in comparison with green bacteria from two other families. A strong dependence of the fluorescence intensity of chlorosomal bacteriochlorophyll c of Osc. trichoides on the redox potential of medium was found, which previously was observed only in green sulfur bacteria. The presence of BChl a in chlorosomes did not appear in their absorption spectra but was visualized by fluorescence spectroscopy at 77 K. From the comparative analysis of fluorescence spectral data for the chlorosomal light-harvesting antenna of Osc. trichoides and similar spectral data for green bacteria from two other families, it was concluded that, in some fluorescence spectral features (spectral position of bacteriochlorophyll c/a fluorescence bands; shape and full width at half maximum fluorescence band of chlorosomal bacteriochlorophyll c; the Stokes shift value of bacteriochlorophyll c band; a high molar ratio of bacteriochlorophyll c : bacteriochlorophyll a in chlorosomes that makes the bacteriochlorophyll a fluorescence band unresolved at room temperature; and highly redox-dependent fluorescence intensity of chlorosomal bacteriochlorophyll c), Osc. trichoides chlorosomes are close to the chlorosomal antenna of Chlorobiaceae species.
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Reduction of Photosystem I Reaction Center in DrgA Mutant of the Cyanobacterium Synechocystis sp. PCC 6803 Lacking Soluble NAD(P)H:Quinone Oxidoreductase. BIOCHEMISTRY (MOSCOW) 2004; 69:445-54. [PMID: 15170383 DOI: 10.1023/b:biry.0000026203.23785.43] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Photoautotrophically grown cells of the cyanobacterium Synechocystis sp. PCC 6803 wild type and the Ins2 mutant carrying an insertion in the drgA gene encoding soluble NAD(P)H:quinone oxidoreductase (NQR) did not differ in the rate of light-induced oxygen evolution and Photosystem I reaction center (P700+) reduction after its oxidation with a white light pulse. In the presence of DCMU, the rate of P700+ reduction was lower in mutant cells than in wild type cells. Depletion of respiratory substrates after 24 h dark-starvation caused more potent decrease in the rate of P700+ reduction in DrgA mutant cells than in wild type cells. The reduction of P700+ by electrons derived from exogenous glucose was slower in photoautotrophically grown DrgA mutant than in wild type cells. The mutation in the drgA gene did not impair the ability of Synechocystis sp. PCC 6803 cells to oxidize glucose under heterotrophic conditions and did not impair the NDH-1-dependent, rotenone-inhibited electron transfer from NADPH to P700+ in thylakoid membranes of the cyanobacterium. Under photoautotrophic growth conditions, NADPH-dehydrogenase activity in DrgA mutant cells was less than 30% from the level observed in wild type cells. The results suggest that NQR, encoded by the drgA gene, might participate in the regulation of cytoplasmic NADPH oxidation, supplying NADP+ for glucose oxidation in the pentose phosphate cycle of cyanobacteria.
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Effects of oxygen on the dark recombination between photoreduced secondary quinone and oxidized bacteriochlorophyll in Rhodobacter sphaeroides reaction centers. BIOCHEMISTRY. BIOKHIMIIA 2002; 67:901-7. [PMID: 12223089 DOI: 10.1023/a:1019966620850] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The influence of duration of exposure to actinic light (from 1 sec to 10 min) and temperature (from 3 to 35 degrees C) on the temporary stabilization of the photomobilized electron in the secondary quinone acceptor (QB) locus of Rhodobacter sphaeroides reaction centers (RC) was studied under aerobic or anaerobic conditions. Optical spectrophotometry and ESR methods were used. The stabilization time increased significantly upon increasing the exposure duration under aerobic conditions. The stabilization time decreased under anaerobic conditions, its dependence on light exposure duration being significantly less pronounced. Generation of superoxide radical in photoactivated aerobic samples was revealed by the ESR method. Possible interpretation of the effects is suggested in terms of interaction between the semiquinone QB with oxygen, the interaction efficiency being determined by the conformational transitions in the structure of RC triggered by actinic light on and off.
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Photocycle in the M-form in bacteriorhodopsin mutants devoid of primary proton acceptor Asp-85. MEMBRANE & CELL BIOLOGY 2002; 14:715-25. [PMID: 11817568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Photoinduced changes in absorption of the deprotonated M-form in the mutant bacteriorhodopsin without primary proton acceptor Asp-85 were studied and additional evidence in support of the complete transmembrane proton transfer in photocycle was obtained. Measurements of the absorption spectrum were carried out at various pH, temperature, and humidity. The direction of proton transfer was the same as in the normal photocycle of the wild-type bacteriorhodopsin: from the internal to the external side of the membrane. The effect on this process of a terminal acceptor Glu-204 was shown.
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Recombination reduction of photooxidized cytochrome c in reaction centers of Rhodopseudomonas viridis at low temperature. BIOCHEMISTRY. BIOKHIMIIA 2001; 66:769-73. [PMID: 11563957 DOI: 10.1023/a:1010264713018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The temperature dependence of dark reduction of photooxidized cytochrome c was studied in isolated preparations of Rhodopseudomonas viridis reaction centers. Within the range from room temperature to approximately 260 K this process was found to be mediated by thermal diffusion of exogenous donor molecules, whereas at lower temperatures photooxidized cytochrome is reduced as a result of indirect recombination with photoreduced primary quinone acceptor. Kinetic simulation allowed certain thermodynamic characteristics of this reaction to be calculated. To the first approximation, these characteristics correlate with the estimates obtained from the results of direct redox titration.
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The dipyridamole effect on the photoactive bacteriochlorophyll interaction with quinone acceptors in reaction centers of purple bacteria. MEMBRANE & CELL BIOLOGY 2001; 14:173-80. [PMID: 11093579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The effect of Dipyridamole (10(-6)-10(-3) M) on the photomobilized electron transport in the system of quinone acceptors Q(A)-Q(B) of isolated photosynthetic reaction centers of Rhodobacter sphaeroides and on its temporary stabilization on Q(B) was studied. Depending on the type of the detergent present in the reaction center (lauryl dimethylamine oxide, Triton X-100, sodium dodecyl sulfate, and sodium cholate), dipyridamole could increase the time of the electron transfer to Q(B). The dipyridamole effect on the efficiency of the electron stabilization on Q(B) for reaction centers with different detergents was revealed in slowing down the process of dark reduction of photoactive bacteriochlorophyll from Q(B) at initial concentrations of added dipyridamole (10(-6)-10(-5) M) with following acceleration of the process at the dipyridamole concentrations of 10(-4)-10(-3) M. The pH lowering from 6.8-7.0 to 5.9-6.0 increased the dipyridamole effect. The possibility of the dipyridamole effect on the structural-dynamic state of the reaction center complex, including its hydrogen bond system, which influences the studied parameters of functional activity, is suggested.
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Effect of dipyridamole on the recombination kinetics between photooxidized bacteriochlorophyll and photoreduced primary quinone in reaction centres of purple bacteria. MEMBRANE & CELL BIOLOGY 2001; 14:37-45. [PMID: 11051080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The action of dipyridamole (DIP) on dark recombination between the photooxidized special pair bacteriochlorophyll BChl2+ and reduced primary quinone acceptor Q(A)- in the reaction centres (RCs) of the bacteria Rhodobacter sphaeroides was studied in the presence of different detergents (LDAO, Triton X-100, sodium cholate, sodium dodecyl sulfate). DIP accelerated this reaction approximately 4-5-fold. In RCs with the extracted H-subunit, the effect of DIP was observed at lower concentrations. The possibility of modification of the RC structure-dynamic state by DIP (including changes in RC hydrogen bonds) is proposed. The modification obviously disturbs the processes of the long-life electrostatic stabilization of Q(A)-.
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Effects of extraction of the H-subunit from Rhodobacter sphaeroides reaction centers on relaxation processes associated with charge separation. BIOCHEMISTRY. BIOKHIMIIA 2001; 66:91-5. [PMID: 11240399 DOI: 10.1023/a:1002893915632] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Effects of extraction of the H-subunit from Rhodobacter sphaeroides photosynthetic reaction centers (RC) on the characteristics of the photoinduced conformational transition associated with electron transfer between photoactive bacteriochlorophyll and primary quinone acceptor were studied. Extraction of the H-subunit (i.e., the subunit that is not directly bound to electron transfer cofactors) was found to have a significant effect on the dynamic properties of the protein--pigment complex of the RC, the effect being mediated by modification of parameters of the relaxation processes associated with charge separation.
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Acceleration of the recombination reaction between photooxidized bacteriochlorophyll and reduced primary quinone in reaction centers of Rhodobacter sphaeroides at T > 300 K. DOKLADY BIOPHYSICS : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOPHYSICS SECTION 2000; 373-375:61-3. [PMID: 11216460 DOI: 10.1023/a:1026652713252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
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[Effect of dipyridamole on recombination of photooxidized bacteriochlorophylla and photoreduced primary quinone in reactive centers of purple bacteria and degradation of form M412 of bacteriorhodopsin]. BIOFIZIKA 2000; 45:648-53. [PMID: 11040971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
It is shown that the addition of dipyridamole (2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido[5,4d]py rim idine) (up to 10(-4) M) leads to a drastic acceleration of the dark recombination reaction between photooxidized bacteriochlorophyll and photoreduced primary quinone in reaction centers of Rhodobacter sphaeroides. The value of the acceleration is similar to that registered under cryogenic temperatures. The extent of the effect of dipyridamole derivatives depended on their structure. In wild-type bacteriorhodopsin and D96N mutant, dipyridamole slowed down the Schiff base reprotonation (the kinetics of M412 form decay was registered). It is suggested that dipyridamole can influence the structural and dynamic state of membrane proteins by affecting the system of their hydrogen-bonds and thus modify electron and proton transport processes.
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