Bacterial photosynthetic reaction center

Although quinone structures and short, non-covalent contacts between quinones and proteins are available from X-ray diffraction structures, analogous information for the quinoidal radicals usually must be inferred indirectly from spectroscopic data. The primary spectroscopic methods used to infer the structures, side-chain conformations, and intermolecular contacts of quinoidal 

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Haran G, Wynne K, Moser 0 0, Dutton P L and Hochstrasser R M 1996 Level mixing and energy redistribution in bacterial photosynthetic reaction centers J. Rhys. Chem. 100 5562-9... 

The bacterial photosynthetic reaction center is built up from four different polypeptide chains and many pigments... 

Figure 12.12 X-ray diffraction pattern from crystals of a membrane-bound protein, the bacterial photosynthetic reaction center. (Courtesy of H. Michel.)...

Rees, D.C., et al. The bacterial photosynthetic reaction center as a model for membrane proteins. Anna. Rev. Biochem. 58 607-633, 1989. 

The ion pore has a narrow ion selectivity filter The bacterial photosynthetic reaction center is built up from four different polypeptide chains and many pigments The L, M, and H subunits have transmembrane a helices... 

Fig.4.30 Immobilization ofthe bacterial photosynthetic reaction center on tailored three-dimensional wormlike mesoporous W03-Ti02 films for artificial photosynthetic systems (A) procedure of film coating (B) proposed scheme of photoelectric conversion. Reprinted with permission from [229], Y. Lu et at., Langmuir 2005, 21, 4071. 2005, American Chemical Society.

Figure 1. Structure of bacterial photosynthetic reaction center. Part of this figure is adapted from Ref. 29.

Ultrafast Dynamics and Spectroscopy of Bacterial Photosynthetic Reaction Centers 1... 

Interpretation of the Primary Electron Transfer in Bacterial Photosynthetic Reaction Centers... 

Q Yang, X-Y Liu, M Hara, P Lundahl, J Miyake. Quantitative affinity chromatographic studies of mitochondrial cytochrome c binding to bacterial photosynthetic reaction center, reconstituted in liposome membranes and immobilized by detergent dialysis and avidin-biotin binding. Anal Chem 280 94-102, 2000. 

Deisenhofer, J. Michel, H. (1991) Structures of bacterial photosynthetic reaction centers. Annu. Rev. Cell Biol. 7, 1-23. Description of the structure of the reaction center of purple bacteria and implications for the function of bacterial and plant reaction centers. 

Woodbury, N. W., M. Becker, D. Middendorf, and W. W. Parson, Picosecond kinetics of the initial photochemical electron transfer reaction in bacterial photosynthetic reaction centers. Biochem. 24 7516, 1985. Fast spectrophotometric techniques are used to follow the initial steps in reaction centers purified from photosynthetic bacteria. 

Sinning, I. (1992). Herbicide binding in the bacterial photosynthetic reaction center. Trends Biochem. Sci., 17 150-154. 

In making rotaxanes usable as parts of molecular devices and with the purpose of studying long range election transfer processes within large molecular systems of well controlled geometries, the introduction of photoactive and electroactive compounds has been a valuable development. Photoinduced electron transfer between porphyrin species has a particular relevance to the primary events occurring in bacterial photosynthetic reaction center complexes, and so is a well studied phenomenon. 

The next two chapters are devoted to ultrafast radiationless transitions. In Chapter 5, the generalized linear response theory is used to treat the non-equilibrium dynamics of molecular systems. This method, based on the density matrix method, can also be used to calculate the transient spectroscopic signals that are often monitored experimentally. As an application of the method, the authors present the study of the interfadal photo-induced electron transfer in dye-sensitized solar cell as observed by transient absorption spectroscopy. Chapter 6 uses the density matrix method to discuss important processes that occur in the bacterial photosynthetic reaction center, which has congested electronic structure within 200-1500cm 1 and weak interactions between these electronic states. Therefore, this biological system is an ideal system to examine theoretical models (memory effect, coherence effect, vibrational relaxation, etc.) and techniques (generalized linear response theory, Forster-Dexter theory, Marcus theory, internal conversion theory, etc.) for treating ultrafast radiationless transition phenomena. 

It should be noted that the ultrafast PIET is usually studied by the pump-probe experiment using ultrashort laser pulses. The probe signals usually include the dynamic information of both coherence and population and to obtain the PIET rate, a theoretical analysis of these signals is required. This has been accomplished for the studies of ultrafast PIET in bacterial photosynthetic reaction centers [22]. 

A microscopic theory for describing ultrafast radiationless transitions in particular for, photo-induced ultrafast radiationless transitions is presented. For this purpose, one example system that well represents the ultrafast radiationless transaction problem is considered. More specifically, bacterial photosynthetic reaction centers (RCs) are investigated for their ultrafast electronic-excitation energy transfer (EET) processes and ultrafast electron transfer (ET) processes. Several applications of the density matrix method are presented for emphasizing that the density matrix method can not only treat the dynamics due to the radiationless transitions but also deal with the population and coherence dynamics. Several rate constants of the radiationless transitions and the analytic estimation methods of those rate... 

Recent rapid developments in ultrashort pulse laser [1-5] make it possible to probe not only the dynamics of population of the system but also the coherence (or phase) of the system. To treat these problems, the density matrix method is an ideal approach. The main purpose of this paper is to briefly describe the application of the density matrix method in molecular terms and show how to apply it to study the photochemistry and photophysics [6-9]. Ultrafast radiationless transactions taking place in bacterial photosynthetic reaction centers (RCs) are very important examples to which the proposed theoretical approach can be applied. 

This review highlights recent studies of synthetic, covalently linked multicomponent molecular devices which mimic aspects of photosynthetic electron transfer. After an introduction to the topic, some of the salient features of natural bacterial photosynthetic reaction centers are described. Elementary electron transfer theory is briefly discussed in order to provide a framework for the discussion which follows. Early work with covalently linked photosynthetic models is then mentioned, with references to recent reviews. The bulk of the discussion concerns current progress with various triad (three-part) molecules. Finally, some even more complex multicomponent molecules are examined. The discussion will endeavor to point out aspects of photoinitiated electron transfer which are unique to the multicomponent species, and some of the considerations important to the design, synthesis and photochemical study of such molecules. 

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