Structures of Bacteriochlorophyll c’s in Chlorosomes from a New Thermophilic Bacterium <i>Chlorobium tepidum</i>

Nozawa, Tsunenori; Ohtomo, Katsunori; Suzuki, Manabu; Morishita, Yumi; Madigan, Michael T.

doi:10.1246/cl.1991.1763

Cited by 15 publications

(3 citation statements)

References 7 publications

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“…An unlabeled sample of BChl c aggregate of the same organism and grown under similar conditions could be separated by HPLC into five components 1-5, numbered in the increasing order of elution times (Table 1). The two major BChl c components (2 and 3), which account for over 90% of the mixture, have been identified earlier on the basis of their !H-NMR and mass spectra (Nozawa et al, 1991b).…”

Section: Resultsmentioning

confidence: 99%

CP-MAS 13C-NMR Dipolar Correlation Spectroscopy of 13C-Enriched Chlorosomes and Isolated Bacteriochlorophyll c Aggregates of Chlorobium tepidum: The Self-Organization of Pigments Is the Main Structural Feature of Chlorosomes

Balaban¹,

Holzwarth²,

Schaffner³

et al. 1995

Biochemistry

143

192

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Magic angle spinning (MAS) NMR dipolar correlation spectroscopy was applied for the first time to a biologically intact system, the light-harvesting chlorosomes of the green photosynthetic bacterium Chlorobium tepidum. The MAS spectra provide evidence that the self-organization of many thousands of bacteriochlorophyll c (BChl c) molecules is the predominant structural feature of the chlorosome. 13C-Enriched chlorosomes were prepared from nonuniformly labeled cultures grown with NaH13CO3 as the main carbon source and from a uniformly 13C-labeled culture grown with NaH13CO3 as the sole carbon source. For the nonuniformly labeled samples, the positions of the chlorin macrocycle originating from C-4 and C-5 of 5-aminolevulinic acid contained > 95% 13C while the remaining positions, which could have originated also from unlabeled acetate, were labeled to approximately 60% with 13C. The 1-D and 2-D MAS data of the labeled chlorosomes, when compared with data on the isolated labeled BChl c aggregated in n-hexane, show that the major component of the MAS signals in the chlorosomes is from BChl c, and only minor signal contributions arise from lipids and proteins. The 13C MAS signals of the BChl c aggregates were fully assigned by MAS 2-D dipolar correlation spectroscopy, using data on monomeric BChl c in CDCl3/CD3OD as reference. The 2(1)-, 3-, 3(2-), 5-, 12(1)-, 13-, and 13(1)-carbons are shifted by 2.5 ppm or more upfield with respect to the solution data.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Resultsmentioning

confidence: 99%

CP-MAS 13C-NMR Dipolar Correlation Spectroscopy of 13C-Enriched Chlorosomes and Isolated Bacteriochlorophyll c Aggregates of Chlorobium tepidum: The Self-Organization of Pigments Is the Main Structural Feature of Chlorosomes

Balaban¹,

Holzwarth²,

Schaffner³

et al. 1995

Biochemistry

143

192

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“…In C. tepidum, BChl c occurs as a number of homologs which differ in the side chains attached to the C-8 and C-12 positions of the chlorin ring (Nozawa et al 1991). Others have correlated the in vivo BChl c spectral shift with variations in the distribution of BChl c homologs (Bobe et al 1990;Borrego and Garcia-Gil 1994;Borrego et al 1999;Chew et al 2007).…”

Section: Hplc Analysis Of Bchl C Homologsmentioning

confidence: 99%

“…Single chlorosomes contain *200,000 BChl c F molecules that self-aggregate into dimers, parallel dimer layers, and higher order rod elements, the major internal structural unit (Egawa et al 2007;Montaño et al 2003). BChl c molecules exist as a set of homologs which differ in the number and identity of alkyl groups on positions 8 and 12 of the chlorin ring (Nozawa et al 1991) that can be resolved by HPLC (Persson et al 2000). Despite being considered low-light specialists (Overmann and Garcia-Pichel 2006), C. tepidum and other green phototrophic bacteria can acclimate to changes in growth light intensity by altering the distribution of BChl c homologs (Bobe et al 1990;Borrego and Garcia-Gil 1994;Borrego et al 1999).…”

Section: Introductionmentioning

confidence: 99%

Chlorobaculum tepidum regulates chlorosome structure and function in response to temperature and electron donor availability

et al. 2008

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Green sulfur bacteria (GSB) rely on the chlorosome, a light-harvesting apparatus comprised almost entirely of self-organizing arrays of bacteriochlorophyll (BChl) molecules, to harvest light energy and pass it to the reaction center. In Chlorobaculum tepidum, over 97% of the total BChl is made up of a mixture of four BChl c homologs in the chlorosome that differ in the number and identity of alkyl side chains attached to the chlorin ring. C. tepidum has been reported to vary the distribution of BChl c homologs with growth light intensity, with the highest degree of BChl c alkylation observed under low-light conditions. Here, we provide evidence that this functional response at the level of the chlorosome can be induced not only by light intensity, but also by temperature and a mutation that prevents phototrophic thiosulfate oxidation. Furthermore, we show that in conjunction with these functional adjustments, the fraction of cellular volume occupied by chlorosomes was altered in response to environmental conditions that perturb the balance between energy absorbed by the light-harvesting apparatus and energy utilized by downstream metabolic reactions.

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Identification of the major chlorosomal bacteriochlorophylls of the green sulfur bacteria Chlorobium vibrioforme and Chlorobium phaeovibrioides; their function in lateral energy transfer

Otte¹,

Meent

Veelen

et al. 1993

Photosynth Res

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The chlorosomal bacteriochlorophyll (BChl) composition of the green sulfur bacteria Chlorobium vibrioforme and Chlorobium phaeovibrioides was investigated by means of normal-phase high-performance liquid chromatography. From both species a number of homologues was isolated, which were identified by absorption and (252)Cf-plasma desorption mass spectroscopy. Besides BChl d, C. vibrioforme contained a significant amount of BChl c, which may provide an explanation for the previous observation of at least two spectrally different pools of BChl in the chlorosomes of green sulfur bacteria (Otte et al. 1991). C. phaeovibrioides contained various homologues of BChl e only. Absorption spectra in acetone of BChl c, d and e, as well as bacteriopheophytin e are presented. No systematic differences were found for the various homologues of each pigment. In addition to farnesol, the mass spectra revealed the presence of various minor esterifying alcohols in both species, including phytol, oleol, cetol and 4-undecyl-2-furanmethanol, as well as an alcohol of low molecular mass, which is tentatively assumed to be decenol.

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Structures of Bacteriochlorophyll c’s in Chlorosomes from a New Thermophilic Bacterium Chlorobium tepidum

Cited by 15 publications

References 7 publications

CP-MAS 13C-NMR Dipolar Correlation Spectroscopy of 13C-Enriched Chlorosomes and Isolated Bacteriochlorophyll c Aggregates of Chlorobium tepidum: The Self-Organization of Pigments Is the Main Structural Feature of Chlorosomes

CP-MAS 13C-NMR Dipolar Correlation Spectroscopy of 13C-Enriched Chlorosomes and Isolated Bacteriochlorophyll c Aggregates of Chlorobium tepidum: The Self-Organization of Pigments Is the Main Structural Feature of Chlorosomes

Chlorobaculum tepidum regulates chlorosome structure and function in response to temperature and electron donor availability

Identification of the major chlorosomal bacteriochlorophylls of the green sulfur bacteria Chlorobium vibrioforme and Chlorobium phaeovibrioides; their function in lateral energy transfer

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