TY - JOUR
T1 - Carotenoid-to-(bacterio)chlorophyll energy transfer in LH2 antenna complexes from Rba. sphaeroides reconstituted with non-native (bacterio)chlorophylls
AU - Niedzwiedzki, Dariusz M.
AU - Swainsbury, David J. K.
AU - Hunter, C. Neil
N1 - Acknowledgements: All spectroscopic work was supported by Photosynthetic Antenna Research Center an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC 0001035. Sample preparation was supported by the Biotechnology and Biological Sciences Research Council (BBSRC UK), Award Number BB/M000265/1. The authors acknowledge Prof. Harry A. Frank for the S 1 excited state fluorescence emission spectrum of 3,4,5,6-tetrahydrospheroidene used in Fig. 5.
PY - 2020/5/1
Y1 - 2020/5/1
N2 - Six variants of the LH2 antenna complex from Rba. sphaeroides, comprising the native B800-B850, B800-free LH2 (B850) and four LH2s with various (bacterio)chlorophylls reconstituted into the B800 site, have been investigated with static and time-resolved optical spectroscopies at room temperature and at 77 K. The study particularly focused on how reconstitution of a non-native (bacterio)chlorophylls affects excitation energy transfer between the naturally bound carotenoid spheroidene and artificially substituted pigments in the B800 site. Results demonstrate there is no apparent trend in the overall energy transfer rate from spheroidene to B850 bacteriochlorophyll a; however, a trend in energy transfer rate from the spheroidene S1 state to Qy of the B800 (bacterio)chlorophylls is noticeable. These outcomes were applied to test the validity of previously proposed energy values of the spheroidene S1 state, supporting a value in the vicinity of 13,400 cm−1 (746 nm).
AB - Six variants of the LH2 antenna complex from Rba. sphaeroides, comprising the native B800-B850, B800-free LH2 (B850) and four LH2s with various (bacterio)chlorophylls reconstituted into the B800 site, have been investigated with static and time-resolved optical spectroscopies at room temperature and at 77 K. The study particularly focused on how reconstitution of a non-native (bacterio)chlorophylls affects excitation energy transfer between the naturally bound carotenoid spheroidene and artificially substituted pigments in the B800 site. Results demonstrate there is no apparent trend in the overall energy transfer rate from spheroidene to B850 bacteriochlorophyll a; however, a trend in energy transfer rate from the spheroidene S1 state to Qy of the B800 (bacterio)chlorophylls is noticeable. These outcomes were applied to test the validity of previously proposed energy values of the spheroidene S1 state, supporting a value in the vicinity of 13,400 cm−1 (746 nm).
KW - Carotenoids
KW - Light harvesting
KW - Light harvesting complex 2
KW - Purple bacteria
KW - Spheroidene
KW - Transient absorption
UR - http://www.scopus.com/inward/record.url?scp=85069703788&partnerID=8YFLogxK
U2 - 10.1007/s11120-019-00661-6
DO - 10.1007/s11120-019-00661-6
M3 - Article
C2 - 31350671
AN - SCOPUS:85069703788
VL - 144
SP - 155
EP - 169
JO - Photosynthesis Research
JF - Photosynthesis Research
SN - 0166-8595
IS - 2
ER -