Dynamics of β-carotene-to-chlorophyll singlet energy transfer in the core of photosystem II
Dynamics of β-carotene-to-chlorophyll singlet energy transfer in the core of photosystem II
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DOI：
10.1021/jp027737q
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发表时间：
2003-06-26
影响因子：
3.3
通讯作者：
van Grondelle, R
中科院分区：
文献类型：
--
作者：
de Weerd, FL;Dekker, JP;van Grondelle, R
光系统II的核心由三个主要的亚配合物组成：光化学反应中心（RC）和核心天线CP43和CP47。它们都含有β -胡萝卜素作为唯一的类胡萝卜素，但在CP43、CP47和RC配合物中β -胡萝卜素到叶绿素单线态能量传递的量子效率较差。通过对β -胡萝卜素激发后分离亚配合物的飞秒瞬态吸收研究，我们发现β -胡萝卜素S-2 (1B（u)(+)）态主要参与了能量转移过程。最多，从“热”β -胡萝卜素S-1 (2A（g)(-)）状态的少量能量转移存在于CP43和CP47中，但这种S-1贡献在RC中不存在。在所有配合物中，松弛的S-1态都不参与能量传递。这种S-1态能量转移的缺失解释了PSII核心中β -胡萝卜素到叶绿素单线态能量转移的总体产量较低。
The core of photosystem II comprises three major subcomplexes: the photochemical reaction center (RC) and the core antennas CP43 and CP47. All contain beta-carotene as the only carotenoid, but the quantum efficiency of beta-carotene-to-chlorophyll singlet energy transfer in the CP43, CP47, and RC complexes is poor. From a femtosecond transient absorption study of the isolated subcomplexes following beta-carotene excitation, we show that mainly the beta-carotene S-2 (1B(u)(+)) state is involved in the energy-transfer process. At most, a minor amount of energy transfer from "hot" beta-carotene S-1 (2A(g)(-)) states is present in CP43 and CP47, but this S-1 contribution is absent in the RC. In all complexes, the relaxed S-1 state is not participating in energy transfer. This absence of energy transfer from S-1 states explains the low overall yield of beta-carotene-to-chlorophyll singlet energy transfer in the PSII core.