TY - JOUR
T1 - How energy funnels from the phycoerythrin antenna complex to photosystem i and photosystem II in cryptophyte rhodomonas CS24 cells
AU - Van Der Weij-De Wit, Chantal D.
AU - Doust, Alexander B.
AU - Van Stokkum, Ivo H.M.
AU - Dekker, Jan P.
AU - Wilk, Krystyna E.
AU - Curmi, Paul M.G.
AU - Scholes, Gregory D.
AU - Van Grondelle, Rienk
PY - 2006/12/14
Y1 - 2006/12/14
N2 - We report an investigation of energy migration dynamics in intact cells of the photosynthetic cryptophyte Rhodomonas CS24 using analyses of steady-state and time-resolved fluorescence anisotropy measurements. By fitting a specific model to the fluorescence data, we obtain three time scales (17, 58, and 113 ps) by which the energy is transferred from phycoerythrin 545 (PE545) to the membrane-associated chlorophylls (Chls). We propose that these time scales reflect both an angular distribution of PE545 around the photosystems and the relative orientations of the donor dihydrobiliverdin (DBV) bilin and the acceptor Chl. Contrary to investigations of the isolated antenna complex, it is demonstrated that energy transfer from PE545 does not occur from a single-emitting bilin, but rather both the peripheral dihydrobiliverdin (DBV) chromophores in PE545 appear to be viable donors of excitation energy to the membrane-bound proteins. The model shows an almost equal distribution of excitation energy from PE545 to both photosystem I (PSI) and photosystem II (PSII), whose trap times correspond well to those obtained from experiments on isolated photosystems.
AB - We report an investigation of energy migration dynamics in intact cells of the photosynthetic cryptophyte Rhodomonas CS24 using analyses of steady-state and time-resolved fluorescence anisotropy measurements. By fitting a specific model to the fluorescence data, we obtain three time scales (17, 58, and 113 ps) by which the energy is transferred from phycoerythrin 545 (PE545) to the membrane-associated chlorophylls (Chls). We propose that these time scales reflect both an angular distribution of PE545 around the photosystems and the relative orientations of the donor dihydrobiliverdin (DBV) bilin and the acceptor Chl. Contrary to investigations of the isolated antenna complex, it is demonstrated that energy transfer from PE545 does not occur from a single-emitting bilin, but rather both the peripheral dihydrobiliverdin (DBV) chromophores in PE545 appear to be viable donors of excitation energy to the membrane-bound proteins. The model shows an almost equal distribution of excitation energy from PE545 to both photosystem I (PSI) and photosystem II (PSII), whose trap times correspond well to those obtained from experiments on isolated photosystems.
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U2 - 10.1021/jp061546w
DO - 10.1021/jp061546w
M3 - Article
C2 - 17149931
AN - SCOPUS:33846062948
SN - 1089-5647
VL - 110
SP - 25066
EP - 25073
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 49
ER -