Rhodopseudomonas sphaeroides

Even entrapment of entire cells within reversed micelles without loss of their functionality has been achieved. For example, mitochondria and bacteria (Actinobacter cal-coaceticus, Escherichia coli, Corynebacterium equi) have been successfully solubilized in a microemulsion consisting of isopropyl pahnitate, polyoxyethylene sorbitan trioleate [162], Enhanced hydrogen photoproduction by the bacterium Rhodopseudomonas sphaeroides or by the coupled system Halobacterium halobium and chloroplasts organelles entrapped inside the aqueous core of reversed micelles with respect to the same cells suspended in normal aqueous medium has been reported [183,184],... 

In the cell-wall antigen from Staphylococcus aureus M, taurine is linked as an amide (51) to a 2-acetamido-2-deoxy-D-galactosyluronic residue. l-Threonine and L-glutamic acid are linked as amides to D-glucuronic acid residues in the LPS from Rhodopseudomonas sphaeroides ATCC 17023 and in the capsular polysaccharide from Klebsiella K82, respectively. In the capsular polysaccharide from E. coli K54, L-serine and L-threonine, in the ratio 1 9, are linked to the carboxyl group of a D-glucuronic acid residue. In the capsular polysaccharide from Haemophilus influenzae type d,... 

Figure 3. The bacterial reaction-center protein model from Rhodopseudomonas sphaeroides the structure and positioning of components are highly speculative.

Rhodobacter sphaeroides R. sphaeroides formerly Rhodopseudomonas sphaeroides... 

Qureshi N, Takayama K, Kurtz R. (1991) Diphosphoryl lipid A obtained from the nontoxic hpopolysaccharide of Rhodopseudomonas Sphaeroides is an endotoxin antagonist in mice. Infect Immun 59 441 44. 

Reaction centers from photosynthetic organisms are specialized pigment-protein complexes in which photon energy is converted into chemical energy ( ) This is accomplished by a series of rapid electron transfer reactions that produce a spacially-separated oxidized donor and a reduced electron acceptor 2). Reaction centers from the purple photosynthetic bacterium Rhodopseudomonas sphaeroides contain four molecules of bacteriochlorophyll (BChl), two of bac-teriopheophytin (BPh), one tightly-bound or primary ubiquinone (Q), a... 

Acyclic Carotenoids. Two pigments from Rhodopseudomonas sphaeroides have been identified as methoxyspheroidene [l,T-dimethoxy-3,4-didehydro-l,2,T,2, 7, 8 -hexahydro-i/f,i/f-carotene (1)] and methoxyspheroidenone [1,T-dimethoxy-3,4-didehydro-1,2,1, 2, 7, 8 -hexahydro-(/f, />-caroten-2-one (2)]. Ano-... 

Sodium lauryl sulfate/benzene Rhodopseudomonas sphaeroides Hydrogen production by cells entrapped in RMs was 25-fold higher [282]... 

Michalski, W. P., and Nicholas, D. j. D. (1987). Inhibition of nitrogenase by nitrite and nitric oxide in Rhodopseudomonas sphaeroides f. sp. denitrificans. Arch. Microbiol. 147, 304-308. 

Brouwer, M. Elferink, M.G.L. Robillard, G.T. Phosphoenolpyruvate-de-pendent fructose phosphotransferase system of Rhodopseudomonas sphaeroides purification and physicochemical and immunochemical characterization of a membrane-associated enzyme I. Biochemistry, 21, 82-88 (1982)... 

Early works on electron transfer in RC from Chromatium vinosum [204] and Rhodopseudomonas sphaeroides [205] demonstrated that these could occur down to 1 K. Then authors of [9] recognized that the oxidation of cytochrome c in Chromatium vinosum at low temperatures occurs by a quantum mechanical tunneling mechanism, providing one of the first demonstrations of this phenomenon (see above and Refs. [232-237] for reviews). Figure 25 which represents the rates of the reactions at ambient temperatures and below 100 K, shows the remarkable capability of reaction centres to support nearly temperature-independent electron transfer at low temperatures. Indeed, for electron transfer from BPh to Qa and from QA to (BChl)2 the rates have been shown to become independent of temperature below 100 K [238-243], But it is necessary to note that electron transfer can occur in a RC also by an alternative thermally activated route which becomes dominant at high enough temperatures [244-248],... 

Fio 12 Flash induced fBChl)J formation and decay in Rhodopseudomonas sphaeroides reaction centre protein (A) - for native RC, (B) - for RC, reconstituted with ubiquinone-7. T = 14 K. From Ref. [258]... 

Qureshi, N., Honovich, J.P., Hara, H., Cotter, R.J., Takayama, K. Location of fatty acids in lipid A obtained from lipopolysaccharide of Rhodopseudomonas sphaeroides ATCC 17023. J Biol Chem 263 (1988) 5502-5504. 

Everybody knows of the spectacular success of unravelling the structure and kinetics of the photosynthetic bacteria, rhodopseudomonas sphaeroides and viridis the structure by Deisenhoffer, Huber and Michel (Deisenhofer et al., 1984) following the isolation and crystallisation by Michel (Michel, 1982) and the picosecond kinetics (which came first) by Rockley, Windsor, Cogdell and Parson (Rockley et al., 1975) and also by Dutton, Rentzepis, Netzel et al. (Netzel et al., 1977). 

Returning to the photosynthetic system it now seems plausible that the explanation for the short charge-separation times in the primary steps must be found in the nature of the medium between the redox-sites involved. In this connection it is interesting to note that saturated hydrocarbon chains (i.e. phytyl sidechains) extend from the special pair and from the menaquinone towards the intermediate bacteriopheophytin (see Fig.l). At this moment it is not clear, however, whether in rhodopseudomonas viridis any of these phytyl sidechains plays the role of a molecular wire (see also Kuhn, 1986) that we attribute to the hydrocarbon bridges in l(n). For rhodopseudomonas sphaeroides a fivefold decrease in the rate of the reverse electron transfer from the quinone (ubiquinone) to the bacteriopheophytin was recently reported to result upon removal of the isoprenoid sidechain from the quinone (Gunner et al., 1986). 

Cogdell, R.J., Parson, W.W. and Kerr, M.A. 1976. The type, amount, location and energy transfer properties of the carotenoid in reaction centers from Rhodopseudomonas sphaeroides. Biochim. Biophys. Acta, 430. 83-93. 

Heathcote, P. and Clayton, R.K. 1977. Reconstituted energy transfer from antenna pigment-protein to reaction centers isolated from Rhodopseudomonas sphaeroides. Biochim. Biophys. Acta, 459. 506-515. 

Satoh, T., and Kurihara, F. N., 1987, Purification and properties of dimediylsulfoxide reductase containing a molybdenum cofactor from a denitrifier, Rhodopseudomonas sphaeroides f.s. denitrificans, J. Biochem. 102 191fil97. 

Crofts, A. R., 1985, The mechanism of ubiquinokcytochrome c oxidoreductases of mitochondria and of Rhodopseudomonas sphaeroides, in The Enzymes of Biological Membranes, Volume 4 (A. N. Martonosi, ed.). Plenum Press, New York, pp. 347n382. 

Meinhardt, S. W., and Crofts, A. R., 1982, The site and mechanism of action of myxothiazol as an inhibitor of electron transfer in Rhodopseudomonas sphaeroides, FEBS Lett. 149 217n222. 

Allen, J. P., Feher, G., Yeates, T. O., Rees, D. C., Deisenhofer, J., Michel, H., and Huber, R., 1986, Structural homology of reaction centers from Rhodopseudomonas sphaeroides and Rhodopseudomonas viridis as determined by X-ray diffraction. Proc. Natl. Acad. Sci. USA, 83 858998593. 

Chang, C. H., Tiede, D., Tang, J., Smith, U., Norris, J., and Schiffer, M., 1986, Structure of Rhodopseudomonas sphaeroides R-26 reaction center. FEBS Letts., 205 82n86. 

Dutton, P. L., Petty, K. M., Bonner, H. S., and Morse, S. D., 1975, Cytochrome c and reaction center of Rhodopseudomonas sphaeroides Ga membranes. Extinction coefficients, content, half-reduction potentials, kinetics and electric field altertions. Biochim. Biophys. Acta, 387 5369556. 

Kirmaier, C., Holten, D., and Parson, W. W., 1985a, Temperature and detection-wavelength dependence of the picosecond electron transfer kinetics measured in Rhodopseudomonas sphaeroides reaction centers Resolution of new spectral and kinetic components in the primary charge-separation process. Biochim. Biophys. Acta, 810 33n48. 

Since the first isolation of a reaction center preparation from the membrane of a facultative photosynthetic bacterium [6] our knowledge on the structure and function of these complexes has made great advances. Today the RC from purple bacteria, and particularly from the carotenoid-less strain R26 of Rhodopseudomonas sphaeroides, are by far the best known examples of photosynthetic complexes studied. Other RC from different bacteria species have also been studied and differences in components sometimes observed these differences will be mentioned below, whenever necessary, while discussing the properties of the preparations from Rp. sphaeroides R26. 

Kim, J. S., Ito, K. and Takahashi, H. (1982). Production of molecular hydrogen in outdoor batch cultures of Rhodopseudomonas sphaeroides. Agric. Biol. Chem. 46,937-941. 

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