A Reconstituted Light-Harvesting Complex from the Green Sulfur Bacterium Chlorobium tepidum Containing CsmA and Bacteriochlorophyll a
| Autor: | Lan Pham, Dorte Bjerre Steensgaard, Mette Miller, Marie Østergaard Pedersen |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Circular dichroism
Spectrophotometry Infrared biology Stereochemistry Circular Dichroism Size-exclusion chromatography Light-Harvesting Protein Complexes Chlorosome Bacteriochlorophyll A Chlorobium biology.organism_classification Biochemistry Light-harvesting complex chemistry.chemical_compound Chlorobium tepidum Bacterial Proteins chemistry Green sulfur bacteria Bacteriochlorophyll Structural motif Chromatography High Pressure Liquid Micelles |
| Zdroj: | Pedersen, M Ø, Pham, L, Steensgaard, D B & Miller, M 2008, ' A reconstituted light-harvesting complex from the green sulfur bacterium Chlorobium tepidum containing CsmA and bacteriochlorophyll a ', Biochemistry, vol. 47, no. 5, pp. 1435-1441 . https://doi.org/10.1021/bi701616r Pedersen, M Ø, Pham, L, Steensgaard, D B & Miller, M 2008, ' A reconstituted light-harvesting complex from the green sulfur bacterium Chlorobium tepidum containing CsmA and bacteriochlorophyll a ', Biochemistry, vol. 47, no. 5, pp. 1435-41 . https://doi.org/10.1021/bi701616r |
| ISSN: | 1520-4995 0006-2960 |
| Popis: | Udgivelsesdato: 2008-Feb-5 Green sulfur bacteria possess two light-harvesting antenna systems, the chlorosome and the Fenna-Matthews-Olson (FMO) protein. In addition to self-aggregated bacteriochlorophyll (BChl) c, chlorosomes of Chlorobium tepidum contain a small amount of BChl a (ratio 100:1). The chlorosomal BChl a is associated with CsmA, a 6.2 kDa protein that accounts for more than 50% of the protein content of chlorosomes. This CsmA-BChl a complex is located in the chlorosome baseplate with the hydrophilic C-terminal part of CsmA in contact with the FMO protein. CsmA was purified from Chl. tepidum. Isolated chlorosomes were lyophilized and extracted with chloroform/methanol (1:1, v/v). The extract was further purified using gel filtration and reverse-phase HPLC and the purity of the preparation confirmed by SDS-PAGE. Mass spectrometric analysis showed an m/z of 6154.8, in agreement with the calculated mass of the csmA gene product after C-terminal processing. CD spectroscopy of the isolated protein showed that the main structural motif was an alpha-helix. We have reconstituted the isolated CsmA protein with BChl a in micelles of n-octyl beta-d-glucopyranoside. The resulting preparation reproduced the spectral characteristics of the CsmA-BChl a complex present in the chlorosome baseplate. |
| Databáze: | OpenAIRE |
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