Go toArchive
Browse byFacets
Bookbag ( 0 )
'Bacterial Photosynthesis' in keywords
Results  3 Items
Sorted by   
Publication Year
1986 (2)
1976 (1)
1Author    Achim TrebstRequires cookie*
 Title    Artificial Energy Conservation in Bacterial Photosynthetic Electron Transport  
 Abstract    In photosynthesis of chloroplasts and bacterial chromatophores an induced artificial electron flow bypass may restore the inhibition of electron flow and of coupled A T P formation by two possible mechanisms. An artificial transmembrane electron flow bypass will lead to artificial energy conservation, when the redox reaction cycle of the added mediator across the membrane acts as proton pump. In an artificial internal electron floiv bypass an inhibited native energy conservation may be reactivated; here an electron flow bypass induced by the mediator in the inside space restores the native proton translocation. The inhibition and the restoration of electron flow by antimycin, dibromothymoquinone and valinomycin 
  Reference    (Z. Naturforsch. 31c, 152 [1976]; received November 24 1975) 
  Published    1976 
  Keywords    Bacterial Photosynthesis, Adenosine Triphosphate Formation, Inhibitors, Photosynthetic Electron Transport 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/31/ZNC-1976-31c-0152.pdf 
 Identifier    ZNC-1976-31c-0152 
 Volume    31 
2Author    R. Steiner, B. Kalumenos, H. ScheerRequires cookie*
 Title    The Photosynthetic Apparatus of Ectothiorhodospira halochloris 3. Effect of Proteolytic Digestion on the Photoactivity  
 Abstract    of Rhodopseudomonas viridis and Ectothiorhodospira halochloris were treated with proteinase K. The photochemical activity (light minus dark difference spectra) were compared to the polypeptide composition (SDS-polyacrylamide gel analysis). In E. halo­ chloris, difference bands appear at 806 (+), 838 (+) and 854 nm (-) . All three decrease in intensity upon incubation with proteinase K., but this decrease is much slower than the proteolysis of both the reaction center and antenna related polypeptides. Photochemical activity remains high as long as a small part of the RC and two lower molecular weight polypeptides M* (22.0 kDa) and B* (15.3 kDa) are present. The M subunit is the most stable polypeptide in the RC of Rp. viridis too, and the photochemical activity is related to the remainder of this and to the one newly formed polypeptide (15.3 kDa), but doesn't show the typical absorption shift of the antenna (B 800/1020 —» B 800/960). The results are discussed quantitatively a containing organisms. 
  Reference    Z. Naturforsch. 41c, 873—880 (1986); received July 17 1986 
  Published    1986 
  Keywords    Bacterial Photosynthesis, Ectothiorhodospira, Reaction Center, Proteolysis, Difference Spectro­ scopy Photosynthetic membranes 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/41/ZNC-1986-41c-0873.pdf 
 Identifier    ZNC-1986-41c-0873 
 Volume    41 
3Author    R. Steiner, A. A. Ngerhofer+, H. ScheerRequires cookie*
 Title    The Photosynthetic Apparatus of Ectothiorhodospira halochloris 2. Accessibility of the Membrane Polypeptides to Partial Proteolysis and Antenna Polypeptide Assignments to Specific Chromophores  
 Abstract    E. halochloris thylakoids and spheroplasts were treated with trypsin, thermolysin or proteinase K to determ ine which proteins are exposed at the different m embrane surfaces. B ased on SD S polyacrylamide analysis, all 9 polypeptides are exposed on the cytoplasm ic side. O nly one (28 k D a) is accessible from the periplasmic side. This polypeptide is generally isolated as the H-subunit o f the reaction centers of photosynthetic bacteria, but is in the case o f E. halochloris rather isolated with the antenna (B 800/1020) (Steiner and Scheer, Biochim . Biophys. A cta 807, 278, 1983). Proteolysis is accom panied by a shift of the absorption band at longest w avelengths from 1020 to 960 nm (B 800/960), which upon standing is shifted further to 680 nm ("B " 800/680). The spectral changes are similar to the ones reported earlier for treatm ent with acid, and are also inducible with urea. The correlation o f SD S-P A G E and absorption spectroscopy show s, that the chrom ophores absorbing at 1020 nm are transformed sim ultaneously with the degradation o f the 6.5 kD a (— a) polypeptide. 
  Reference    Z. Naturforsch. 41c, 571 (1986); received January 9 1986 
  Published    1986 
  Keywords    Bacterial Photosynthesis, Ectothiorhodospira, M embrane T opology, A ntenna Polypeptides, F luorescence, Circular D ichroism, Energy Transfer 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/41/ZNC-1986-41c-0571.pdf 
 Identifier    ZNC-1986-41c-0571 
 Volume    41