Membranes of Rhodopseudomonas sphaeroides. IV. Assembly of chromatophores in low-aeration cell suspensions

Niederman, Robert A.; Mallon, David E.; Langan, James J.

doi:10.1016/0005-2728(76)90076-1

Cited by 109 publications

(51 citation statements)

References 44 publications

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“…In accord with a pathway of energy transfer from B850 through B875 to reaction centers (20,38), it was proposed that B875 interconnects and surrounds reaction centers and that the vast array of B850 is arranged peripherally in larger "lakes" (32). A close association between the reaction centers and B875 has been suggested by their fixed stoichiometry in cells of varying pigment contents (6) and the observation that these are the first complexes synthesized during repigmentation (7). Our In accord with the polypeptide composition reported for other antenna preparations (11,25,28), three polypeptide bands observed near the gel front in purified chromatophore preparations were designated (29) as LH-1 to LH-3 (apparent Mr, 12,000, 10,000, and 8000, respectively).…”

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confidence: 97%

“…Absorption spectra reveal two antenna complexes designated B850 and B875 on the basis of their absorption maxima in the near-infrared (5). B875 is associated with the reaction center in a molar ratio of about 30:1 (6), unlike B850 levels which vary with changes in light intensity (6) or the stage of membrane development (7). A detailed understanding of these Bchlprotein complexes requires their isolation from the membrane.…”

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confidence: 99%

“…Chromatophores were purified from French-press extracts as described (7). All membrane isolation procedures were carried out at 4°C; buffers contained 1.0 mM phenylmethylsulfonyl fluoride (PMSF) to inhibit protease activity.…”

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confidence: 99%

“…Procedures for pigment determinations have been described (7). Values obtained for spheroidene and spheroidenone were verified after separation by thin-layer chromatography (14).…”

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confidence: 99%

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Isolation and characterization of the pigment-protein complexes of Rhodopseudomonas sphaeroides by lithium dodecyl sulfate/polyacrylamide gel electrophoresis.

Broglie¹,

Hunter²,

Delepelaire³

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

154

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When purified photosynthetic membranes from Rhodopseudomonas sphaeroides were treated with lithium dodecyl sulfate and subjected to polyacrylamide gel electrophoresis at 4VC, up to 11 pigment-protein complexes were resolved. Absorption spectra revealed that the smallest complex contained reaction center pigments and the others contained the antenna components B850 and B875 in various proportions. Of these antenna complexes, the largest was almost entirely B850 and the smallest contained only B875. After solubilization at 1000C and electrophoresis on polyacrylamide gradient gels, the B850 complex gave rise to two polypeptide components migrating with apparent M, of 10,000 and 8000, whereas with the B875 complex, two components were observed with apparent Mr of 12,000 and 8000. The reaction center complex gave rise to only the 24 The photosynthetic apparatus of the photoheterotrophic bacterium Rhodopseudomonas sphaeroides is localized in a system of intracytoplasmic membranes (1) which, upon mechanical disruption, gives rise to vesicles termed "chromatophores" (2). These contain most of the antenna (light-harvesting) and reaction center bacteriochlorophyll a (Bchl)-protein complexes (2). Radiant energy harvested by antenna migrates to the reaction center where productive photochemistry occurs (3, 4). Absorption spectra reveal two antenna complexes designated B850 and B875 on the basis of their absorption maxima in the near-infrared (5). B875 is associated with the reaction center in a molar ratio of about 30:1 (6), unlike B850 levels which vary with changes in light intensity (6) or the stage of membrane development (7). A detailed understanding of these Bchlprotein complexes requires their isolation from the membrane. After detergent treatment, reaction center preparations have been purified from chromatophores of both the carotenoidless mutant R-26 (8, 9) and the wild type (10); similarly, the B850 complex has also been isolated from the latter (11). To our knowledge, no reports on the isolation of B875 from wild-type R. sphaeroides have appeared.Recently, a novel procedure has been developed for the isolation of chlorophyll-protein complexes from thylakoid membranes of Chlamydomonas reinhardtii and higher plants (12). After solubilization of membranes in lithium dodecyl sulfate (LiDodSO4) and polyacrylamide gel electrophoresis with this detergent at 40C, two new chlorophyll-protein complexes were isolated. Under these conditions, the dissociation of pigment from the complexes is minimized. LiDodSO4 was used because the sodium salt, previously used, precipitates in the cold. It is shown here that, in R. sphaeroides wild-type chromatophores, LiDodSO4/polyacrylamide gel electrophoresis provides a convenient procedure for the isolation of the B875-antenna complex in addition to B850 and reaction centers that lack the heavy subunit.MATERIALS AND METHODS R. sphaeroides (NCIB 8253) was grown phototrophically at 30°C essentially as described (13) with 40-W General Electric incandescent lamps at a light intensi...

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confidence: 97%

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Procedures for pigment determinations have been described (7). Values obtained for spheroidene and spheroidenone were verified after separation by thin-layer chromatography (14).…”

mentioning

confidence: 99%

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Isolation and characterization of the pigment-protein complexes of Rhodopseudomonas sphaeroides by lithium dodecyl sulfate/polyacrylamide gel electrophoresis.

Broglie¹,

Hunter²,

Delepelaire³

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

154

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“…An additional peripheral light-harvesting complex, LH2, also referred to as B800-850, occurs in variable amounts in response to environmental levels of light and oxygen (1,2).…”

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Modification of a hydrogen bond to a bacteriochlorophyll a molecule in the light-harvesting 1 antenna of Rhodobacter sphaeroides.

Olsen

Sockalingum

Robert

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

119

141

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Site-directed mutagenesis has been used to examine the function of a highly conserved aromatic residue, darp43, in the light-harvesting 1 antenna ofthe photosynthetic bacterium Rhodobacter sphaeroides. In this antenna dfrp43 is thought to be located near the putative binding site for bacteriochlorophyll; in this work it was changed to both Tyr and The photosynthetic apparatus of the purple bacterium Rhodobacter sphaeroides consists of a membrane protein complex, the reaction center (RC), surrounded by a core light-harvesting complex, LH1, also referred to as B875, in a fixed stoichiometry of -12 LH1 a(3 dimers per RC. An additional peripheral light-harvesting complex, LH2, also referred to as B800-850, occurs in variable amounts in response to environmental levels of light and oxygen (1, 2). The structure of the RC of Rb. sphaeroides is known to atomic resolution (3, 4); however, the structures of the LH1 and LH2 complexes are not known, although diffracting crystals ofvarious LH complexes have been reported (5-10). As yet, these structures have not been solved, so it is necessary to employ other methods such as mutagenesis and spectroscopy to obtain relevant data. As a result of these approaches, more information is becoming available on the interaction of the chromophores of LH1 and LH2 with nearby residues of the antenna polypeptides (11,12). These data can be used to test existing model structures derived from spectroscopic and electrophoretic mobility studies of wild-type (WT) complexes. The models that have been proposed for bacterial LH complexes all follow a similar pattern in that the af8 heterodimer, which in the case of LH1 would bind 2 bacteriochlorophyll (bchl) molecules, is considered to be the minimum possible building block. The topology and conformation of these subunits are thought to be similar, each with a cytoplasmically exposed N terminus, a single transmembrane helix, and a periplasmic C terminus. There are indications of turns at or near the membrane interfaces (13 (20), and Rhodocyclus gelatinosus (21), leading to the speculation that this bchl dimer is the building block of the LH1 complex. Characterization of the B820 form (22) supports the idea that it is an excitonically coupled bchl a dimer. Moreover, resonance Raman measurements of the B820 showed that it differed from the B873 form in the interactions of the C2 acetyl carbonyl; the loss of a H bond was one possible explanation of the Raman data. A more detailed Raman study of the LH1 ofRs. rubrum G9 has shown that upon formation of the B820, the strength of one H bond was increased (23 FT, Fourier transform; WT, wild type; P-OG, n-octyl P-Dglucopyranoside; ODPS, n-octyldipropyl sulfoxide. 7124The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

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Chemoautotrophic growth of Thiocystis violacea, Chromatium gracile and C. vinosum in the dark at various O₂‐concentrations

Kämpf

Pfennig

1986

J. Basic Microbiol.

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Tlie influence of various 0,-concentrations on chemoautotrophic growth was dcterniincd in thc range from microaerobic t o aerobic conditions. Chromatium vinosurn D, Thiocystis violacea 231 1 and Chromatiurn yracile 25-1 were grown chemoautotropliically using consecutively repeated batch riiltures. Rapid growth of all thrce strains occurred only under microaerobic conditions. Thc fastcst growth (1.c = 0.058) was obtained with Chromatium gracile 25-1 grown in the prcsence of 1 mg 0, . 1 -l. For optimal chemoautotrophic growth aulfur-containing cells had to bc supplied continuously with cxtracellular electron donor. Multiplication of Thiocystis violacea 231 1 and Chromatiwn gracile 25-1 was significantly inhibited after several cell generations, while Chromatiurn winosum D could be grown unlimited. I n case of the latter bacterium any given 0,-concentration determined il unique growth rate and a unique specific bclil a content. The analysis of absorption spect.ra of whole cclls revealed that different pigment complexes were regulated separately by oxygen. Growth yields were not dependent on the 0,-concentration. A growth yield of 12 g dry cell mass per mol of thiosulfate oxidized was determined for Chromatium vinosum D growing in the micro-to semiaerobic 0,-concentration range. When compared to phototrophically grown cells, the catalase content of chemotrophically grown cells was 2 times lower while the maximal specific respiration rate of the cells was 7 times higher. The ecological significance of the kinetics of chemotrophic growth under various growth conditions is discussed.

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Membranes of Rhodopseudomonas sphaeroides. IV. Assembly of chromatophores in low-aeration cell suspensions

Cited by 109 publications

References 44 publications

Isolation and characterization of the pigment-protein complexes of Rhodopseudomonas sphaeroides by lithium dodecyl sulfate/polyacrylamide gel electrophoresis.

Isolation and characterization of the pigment-protein complexes of Rhodopseudomonas sphaeroides by lithium dodecyl sulfate/polyacrylamide gel electrophoresis.

Modification of a hydrogen bond to a bacteriochlorophyll a molecule in the light-harvesting 1 antenna of Rhodobacter sphaeroides.

Chemoautotrophic growth of Thiocystis violacea, Chromatium gracile and C. vinosum in the dark at various O₂‐concentrations

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Membranes of Rhodopseudomonas sphaeroides. IV. Assembly of chromatophores in low-aeration cell suspensions

Cited by 109 publications

References 44 publications

Isolation and characterization of the pigment-protein complexes of Rhodopseudomonas sphaeroides by lithium dodecyl sulfate/polyacrylamide gel electrophoresis.

Isolation and characterization of the pigment-protein complexes of Rhodopseudomonas sphaeroides by lithium dodecyl sulfate/polyacrylamide gel electrophoresis.

Modification of a hydrogen bond to a bacteriochlorophyll a molecule in the light-harvesting 1 antenna of Rhodobacter sphaeroides.

Chemoautotrophic growth of Thiocystis violacea, Chromatium gracile and C. vinosum in the dark at various O2‐concentrations

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Chemoautotrophic growth of Thiocystis violacea, Chromatium gracile and C. vinosum in the dark at various O₂‐concentrations