40 research outputs found
Properties of Hybrid Complexes Composed of Photosynthetic Reaction Centers from the Purple Bacterium Rhodobacter sphaeroides and Quantum Dots in Lecithin Liposomes
No full textA photosynthetic reaction center (RC) is a natural mesoscopic structure with dimensions of ~10 nm However, for creating a RC-based hybrid energy transformer it is necessary to solve some problems. First, it is necessary to obtain a high stability of photosynthetic pigment-protein complexes in vitro, because without photoprotection and repair systems they are subject to pronounced photodestruction. Second, the solar light absorption by the pigment-protein complexes of RCs is not equally efficient throughout the whole spectrum: the main absorption bands of the RC pigments are in the blue and near infrared regions of the spectrum, and it is impor- ISSN 0006-2979, Biochemistry (Moscow), 2014, Vol. 79, No. 11, pp. 1183-1191. © Pleiades Publishing, Ltd., 2014. Original Russian Text © V. E. Zagidullin, E. P. Lukashev, P. P. Knox, N. Kh. Seifullina, O. S. Sokolova, E. V. Pechnikova, H. Lokstein, V. Z. Paschenko, 2014, published in Biokhimiya, 2014, Vol. 79, No. 11, pp. 1452-1463 On-Line Papers in Press, as Manuscript BM14-145, Published on September 7, 2014. 1183 Abbreviations: BChl, bacteriochlorophyll; BPheo, bacteriopheophytin; D-D, detergent-and dialysis-based method of liposomes preparation; RC, photosynthetic reaction center; QDs, quantum dots. * To whom correspondence should be addressed. Abstract-Quantum dots (QDs) can absorb ultraviolet and long-wavelength light energy much more efficiently than natural light-harvesting proteins and transfer the excitation energy to photosynthetic reaction centers (RCs). Inclusion into liposomes of RC membrane pigment−protein complexes combined with QDs as antennae opens new opportunities for using such hybrid systems as a basis for artificial energy-transforming devices that potentially can operate with greater efficiency and stability than devices based only on biological components. RCs from Rhodobacter sphaeroides and QDs with fluorescence maximum at 530 nm (CdSe/ZnS with hydrophilic covering) were embedded in lecithin liposomes by extrusion of a solution of multilayer lipid vesicles through a polycarbonate membrane or by dialysis of lipids and proteins dispersed with excess detergent. The dimensions of the resulting hybrid systems were evaluated using dynamic light scattering and by transmission cryoelectron microscopy. The efficiency of RC and QD interaction within the liposomes was estimated using fluorescence excitation spectra of the photoactive bacteriochlorophyll of the RCs and by measuring the fluorescence decay kinetics of the QDs. The functional activity of the RCs in hybrid complexes was fully maintained, and their stability was even increased. Properties of Hybrid Complexes Composed of Photosyntheti
On the Relationship Between Structural and Dynamic Properties in Purple Bacteria Reaction Centers and Stabilization of Photomobilized Electron on Quinone Acceptors
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Using of the 120-cm cyclotron for the study of simultaneous ionizing radiation and hypomagnetic conditions effects on the simplest biological objects
No full textSection V. Equipment, Methods and Automation of Nuclear Experiments, Interaction of Nuclear Radiation with the Matter and Applications of Methods of Nuclear PhysicsThe work was performed by using equipment purchased by "Program for Development of Moscow University"
Influence of Hydrogen Bonds on the Energy and Electron Transfer in Reaction Centers of Rhodobacter Sphaeroides
No full textApplication of the standard theory of electronic transitions to the description of oscillations in the kinetics of electron transfer in reaction centers of purple bacteria
No full textPhotophysical processes of energy conversion in thylakoid membranes of Chlamydomonas reinhardtii mutants D1-R323H, D1-R323D, and D1-R323L
No full textPhotosystem 2 effective fluorescence cross-section of cyanobacterium Synechocystis sp. PCC6803 and its mutants
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