Browsing by Subject "Photosynthetic bacteria"
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Item Biophysical characterization of several hemoproteins from the photosynthetic bacteria, Chromatium vinosum and Rhodospirillum rubrum(Texas Tech University, 1985-08) Gaul, Dale FrancisNot availableItem Cation/amino acid symports in the photosynthetic bacterium Chromatium vinosum(Texas Tech University, 1984-05) Cobb, K. AndreaNot availableItem Item Ion transport in photosynthetic purple bacteria(Texas Tech University, 1982-08) Davidson, Victor LesterNot availableItem Molecular biology of photosynthetic bacteria(Texas Tech University, 1997-12) Corson, Gary E.The photosynthetic reaction center of purple bacteria is a multimeric, membraneassociated protein/chromophore complex. The function of the photosynthetic reaction center is to catalyze light-driven electron transfer across the photosynthetic membranes. The photosynthetic reaction centers of purple bacteria have been well characterized, and all of them contain three subunits that are designated as L (light), M (medium), H (heavy). The designation of the subunits is based upon their apparent molecular masses as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis under denaturing conditions. Photosynthetic reaction centers are also associated with light harvesting complexes, that absorb light energy and transfer it to the bacteriochlorophyll dimer ("special pair") that serves as the primary electron donor in the reaction center. The light harvesting complex is composed of (3 and a proteins, to which are bound pigment molecules.Item Photosynthetic and respiratory electron transport chains in purple and green phototrophic bacteria(Texas Tech University, 1986-05) Wynn, Richard MaxNot availableItem Studies of the cytochrome bc1 complex and its electon acceptors in purple photosynthetic bacteria(Texas Tech University, 2001-12) Li, JunThe cytochrome bc1 complex is a key component of electron transfer chains in mitochondria and in many aerobic and photosynthetic bacteria. The bc1 complexes from photosynthetic bacteria provide many advantages for understanding electron transfer through the complex, as they are structurally simpler than the mitochondrial complexes and fast electron transfer after photoactivation of the reaction center can be easily followed using absorbance changes, something that cannot be done with mitochondria. This dissertation focuses on three aspects related to the bc1 complexes: (1) The role of HiPIP and cytochrome cg, which are reduced by the bc1 complex, as alternative electron donors to the reaction center of Chromatium vinosum. Laser flash kinetics with intact Cm. vinosum cells showed that either HiPIP or cytochrome cg can be an efficient electron donor to the reaction center, depending on the media used to grow the cells. However, the preference for one electron donor over another does not arise from significant differences in protein abundance in the cells grown in the two different media. The mechanism of this "switch" remains to be elucidated. (2) Spectroscopic and oxidation-reduction properties of M183K and M183H variants of Rhodobacter capsulatus cytochrome c8. MCD and EPR spectra suggest that Rb. capsulatus cyt c\ is flexible and that one of the three histidines present outside the normal heme-binding domain can be recruited as an alternative to the methionine heme ligand found in the wild-type cytochrome. Titrations carried out in the oxidative direction differ markedly from those carried out in the reductive direction, mdicating the possible occurrence of redox-triggered conformational changes. (3) Interaction between Rb. capsulatus cytochrome bc1 and equine cytochrome c (a homolog for Rb. capsulatus cytochrome C2). Steady-state kinetic data, using site-specific cyt c1 mutants, showed that one acidic patch on the surface of cytochrome ci is unlikely to be involved in binding to cytochrome c. However, both steady-state kinetics and redox titration revealed that the phenylanaline at position 138 plays a critical role m maintaining a normal heme environment and suggest that this aromatic amino acid may participate in mediating electron transfer to and/or from the heme of cyt c1.Item Studies on flavocytochromes from photosynthetic sulfur bacteria(Texas Tech University, 1986-05) Davidson, Michael WNot availableItem The isolation and characterization of the quinol:cytochrome C oxidoreductase from Rhodospirillum rubrum(Texas Tech University, 1988-12) Kriauciunas, Aidas VladasNOT AVAILABLE