Carbon-13 magic angle spinning NMR evidence for a 15,15'-cis configuration of the spheroidene in the Rhodobacter sphaeroides photosynthetic reaction center
Citations Over Time
Abstract
The photosynthetic reaction center of Rhodobacter sphaeroides 2.4.1 contains one carotenoid that protects the protein complex against photodestruction. The structure around the central (15,15') double bond of the bound spheroidene carotenoid was investigated with low-temperature magic angle spinning 13C NMR, which allows an in situ characterization of the configuration of the central double bond in the carotenoid. Carotenoidless reaction centers of R. sphaeroides R26 were reconstituted with spheroidene specifically labeled at the C-14' or C-15' position, and the signals from the labels were separated from the natural abundance background using 13C MAS NMR difference spectroscopy. The resonances shift 5.2 and 3.8 ppm upfield upon incorporation in the protein complex, similar to the 5.6 and 4.4 ppm upfield shift occurring in the model compound beta-carotene upon trans to 15,15'-cis isomerization. Hence the MAS NMR favors a cis configuration, as opposed to the trans configuration deduced from X-ray data.
Related Papers
- → Bacteriopheophytin a in the Active Branch of the Reaction Center of Rhodobacter sphaeroides Is Not Disturbed by the Protein Matrix as Shown by 13C Photo-CIDNP MAS NMR(2013)12 cited
- → 13C Photo-CIDNP MAS NMR on the Reaction Center of Green Sulphur Bacterium at Two Different Magnetic Fields(2008)4 cited
- → Carbon-13 magic angle spinning NMR evidence for a 15,15'-cis configuration of the spheroidene in the Rhodobacter sphaeroides photosynthetic reaction center(1992)37 cited
- → 13C Magic angle spinning NMR evidence for a 15,15’-Z configuration of the spheroidene chromophore in the Rhodobacter sphaeroides reaction center; synthesis of 13C- and 2H-labelled spheroidenes(1991)27 cited
- → Magic Angle Spinning Nuclear Magnetic Resonance of Photosynthetic Components(1996)5 cited