Disease relevance of Spheroidene

• Unusually large electric field effects have been measured for the absorption spectra of carotenoids (spheroidene) in the B800-850 light-harvesting complex from the photosynthetic bacterium Rhodobacter sphaeroides [1].
• The structure of spheroidene in Y reaction center is compared to that proposed for 1,2-dihydroneurosporene in Rhodopseudomonas viridis reaction center crystals [2].
• Like all known Rhodovulum species, the new strains had ovoid to rod-shaped cells, contained bacteriochlorophyll a and carotenoids of the spheroidene series, and were able to oxidize sulfide and thiosulfate [3].
• Methylated carotenoids, such as spheroidene and spirilloxanthin, are known to function as accessory pigments in the light-harvesting and reaction-center complexes of purple bacteria; the demethylated carotenoids described here were able to fulfill the same functions in the mutants [4].

High impact information on Spheroidene

• An associated phenotype, involving the enhanced conversion of the carotenoid spheroidene to spheroidenone, is also observed in the RdxB, -H, -I, and -S mutant strains [5].
• Anaerobic carotenoid biosynthesis in Rhodobacter sphaeroides 2.4.1: H2O is a source of oxygen for the 1-methoxy group of spheroidene but not for the 2-oxo group of spheroidenone [6].
• The cells of strain JA125(T) contained vesicular internal membranes and bacteriochlorophyll a and carotenoids of the spheroidene series [7].
• Enzyme kinetic studies including the determination of substrate specificity constants indicate that among the alternative biosynthetic routes to 1'-HO-spheroidene the one via spheroidene is the dominating pathway [8].
• When the crtI deletion mutant was complemented by the three-step phytoene desaturase of Rhodobacter capsulatus, spirilloxanthin and its precursors were not synthesized, although spheroidene and OH-spheroidene were accumulated [9].

Chemical compound and disease context of Spheroidene

• Four carotenoids, 3,4,7,8-tetrahydrospheroidene, 3,4,5,6-tetrahydrospheroidene, 3,4-dihydrospheroidene and spheroidene, have been incorporated into the B850 light-harvesting complex of the carotenoidless mutant, photosynthetic bacterium, Rhodobacter sphaeroides R-26 [10].
• As a step towards the structural analysis of the carotenoid spheroidene in the Rhodobacter sphaeroides reaction centre, we present the resonance Raman spectra of 14-2H, 15-2H, 15'-2H, 14'-2H, 14,15'-2H2 and 15-15'-2H2 spheroidenes in petroleum ether and, except for 14,15'-2H2 spheroidene, in the Rb. sphaeroides R26 reaction center (RC) [11].

Biological context of Spheroidene

• Triplet energy transfer between the primary donor and carotenoids in Rhodobacter sphaeroides R-26.1 reaction centers incorporated with spheroidene analogs having different extents of pi-electron conjugation [12].

Anatomical context of Spheroidene

• Strain JA128(T) contained vesicular intracytoplasmic membranes, bacteriochlorophyll a and carotenoids of the spheroidene series [13].

Associations of Spheroidene with other chemical compounds

• The S(1)-mediated carotenoid-to- bacteriochlorophyll energy transfer efficiencies were determined to be 96%, 84%, and 73% for neurosporene, spheroidene, and spheroidenone, respectively [14].

Analytical, diagnostic and therapeutic context of Spheroidene

• Towards a vibrational analysis of spheroidene. Resonance Raman spectroscopy of 13C-labelled spheroidenes in petroleum ether and in the Rhodobacter sphaeroides reaction centre [15].

References