Quantitation of P840 reaction center preparations from Chlorobium tepidum: chlorophylls and FMO-protein
| Autor: | Christoph Griesbeck, Hans Rogl, Günter Hauska, Christine Hager-Braun |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Photosynthetic reaction centre
biology Chemistry Stereochemistry Biophysics chemistry.chemical_element Cell Biology biology.organism_classification Photochemistry Sulfur Biochemistry (Chlorobium tepidum) chemistry.chemical_compound Chlorobium tepidum Membrane Extinction coefficient for bacteriochlorophyll a Fenna-Mathews-Olson protein Green sulfur bacteria Bacteriochlorophyll Bacteriochlorophyll A P840 reaction center Bacteria |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1365(1-2):285-293 |
| ISSN: | 0005-2728 |
| DOI: | 10.1016/s0005-2728(98)00081-4 |
| Popis: | Bacteriochlorophyll a is extracted from the reaction center complex and the Fenna-Mathews-Olson protein (FMO) of the green sulfur bacterium Chlorobium tepidum into organic solvent at different time scales. This allows the distinction of bacteriochlorophyll a bound to the reaction center and to FMO. The average extinction coefficients of bacteriochlorophyll a in the reaction center and in FMO are 90 and 153 mM−1 cm−1 and thus differ by a factor of 1.7. With this the amount of FMO present per reaction center in membranes and isolates from green sulfur bacteria requires re-evaluation. The reaction center core from which FMO has been removed contains 135 μg protein per ml and OD unit cm−1 at the Qy peak and binds 16 bacteriochlorophylls a plus four chlorophylls a. The functionally intact RC with five subunits can also be separated from contaminating FMO trimers, but retains one to two FMO proteins. Membranes contain about five FMO proteins per reaction center, substantially less than considered before. |
| Databáze: | OpenAIRE |
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