Properties of the reaction center of the thermophilic purple photosynthetic bacterium Chromatium tepidum
| Autor: | James D. McManus, Robert E. Blankenship, Taisei Fukada, Tsunenori Nozawa, Jeffrey T. Trost, Masahiro Hatano |
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| Rok vydání: | 1987 |
| Předmět: |
Photosynthetic reaction centre
Cytochrome Stereochemistry Chromatium Photosynthetic Reaction Center Complex Proteins Biophysics Photochemistry Biochemistry chemistry.chemical_compound Chromatiaceae Bacterial Proteins Heme Photosystem biology Cytochrome c Circular Dichroism Quinones Cell Biology biology.organism_classification chemistry Spectrophotometry biology.protein Cytochromes Electrophoresis Polyacrylamide Gel Photosynthetic bacteria |
| Zdroj: | Biochimica et biophysica acta. 894(3) |
| ISSN: | 0006-3002 |
| Popis: | Reaction centers were purified from the thermophilic purple sulfur photosynthetic bacterium Chromatium tepidum. The reaction center consists of four polypeptides L, M, H and C, whose apparent molecular masses were determined to be 25, 30, 34 and 44 kDa, respectively, by polyacrylamide gel electrophoresis. The heaviest peptide corresponds to tightly bound cytochrome. The tightly bound cytochrome c contains two types of heme, high-potential c-556 and low-potential c-553. The low-potential heme is able to be photooxidized at 77 K. The reaction center exhibits laser-flash-induced absorption changes and circular dichroism spectra similar to those observed in other purple photosynthetic bacteria. Whole cells contain both ubiquinone and menaquinone. Reaction centers contain only a single active quinone; chemical analysis showed this to be menaquinone. Reaction center complexes without the tightly bound cytochrome were also prepared. The near-infrared pigment absorption bands are red-shifted in reaction centers with cytochrome compared to those without cytochrome. |
| Databáze: | OpenAIRE |
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