Light-induced changes of NADPH fluorescence in isolated chloroplasts: a spectral and fluorescence lifetime study
Light-induced changes of NADPH fluorescence in isolated chloroplasts: a spectral and fluorescence lifetime study
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DOI：
10.1016/s0005-2728(00)00198-5
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发表时间：
2000-11-20
影响因子：
4.3
通讯作者：
Moya, I
中科院分区：
文献类型：
--
作者：
Latouche, G;Cerovic, ZG;Moya, I
分离的叶绿体显示出光诱导的可逆的蓝绿色荧光(BGF)增加，这只依赖于NADPH的变化。在本文中，我们报道了在黑暗和光化光照下，重组叶绿体和完整分离叶绿体中这种BGF的时间分辨和光谱分析。根据这些测量，我们推断了不同形式的NADPH(游离的和与蛋白质结合的)对光诱导的BGF变化的贡献，并得出结论：这种变化仅仅是由于NADP池的氧化还原变化。设计了一个简单的模型来估计NADPH在游离态和结合态之间的分布，该模型解释了重组叶绿体和完整叶绿体BGF的测量差异。根据叶绿体BGF的衰变相关光谱，我们还推测了黄素参与了叶绿体荧光发射光谱的绿峰，并推测了叶绿体中存在从蛋白质到结合NADPH的激发能量转移。此外，我们重新研究了叶绿体BGF作为NADPH浓度的定量测量的用途，并证实了叶绿体BGF可以用于非破坏性的、连续的、甚至可能是定量监测光诱导的NADP氧化还原状态的变化。(C)2000 Elsevier Science B.V.保留所有权利。
Isolated chloroplasts show a light-induced reversible increase in blue-green fluorescence (BGF), which is only dependent on NADPH changes. In the present communication, we report a time-resolved and spectral analysis of this BGF in reconstituted chloroplasts and intact isolated chloroplasts, in the dark and under actinic illumination. From these measurements we deduced the contribution of the different forms of NADPH (free and bound to proteins) to the light-induced variation of BGF and conclude that this variation is due only to the redox change of the NADP pool. A simple model estimating the distribution of NADPH between the free and bound form was designed, that explains the differences measured for the BGF of reconstituted chloroplasts and intact chloroplasts. From the decay-associated spectra of the chloroplast BGF, we also deduced the participation of flavins to the green peak of chloroplast fluorescence emission spectrum, and the existence of excitation energy transfer from proteins to bound NADPH in chloroplasts. In addition, we reexamined the use of chloroplast BGF as a quantitative measure of NADPH concentration, and confirmed that chloroplast BGF can be used for non-destructive, continuous and probably quantitative monitoring of light-induced changes in NADP redox state. (C) 2000 Elsevier Science B.V. All rights reserved.