排序方式: 共有13条查询结果,搜索用时 15 毫秒
1.
研究了人工合成的藻胆体模拟复合物的时间分辨荧光光谱,并运用多指数拟合的方法对数据进行了详细的处理和分析,结果表明能量在R-PE和R-PC之间的传递时间与能量从R-PC传递到APC的时间几乎相等(50ps);除此之外,R-PE到APC还有两种能量传递的通道,能量在这两个通道的传递时间分别为110ps和400ps.即:蛋白之间的能量传递通道是并行的. 相似文献
2.
藻胆体是一些光合藻类吸收传递光能的色素蛋白复合体,设计面向生命科学高年级本科生的综合实验,包括了藻胆体的分离、纯化、组成鉴定及性质分析,详细分析了该综合实验的特点、具有的优势以及存在的问题。 相似文献
3.
《科学通报(英文版)》2008,(21)
Pbycobilisomes(PBS) are able to transfer absorbed energy to photosystem I and Ⅱ,and the distribution of light energy between two photosystems is regulated by state transitions.In this study we show that energy transfer from PBS to photosystem I(PSI) requires ApcD.Cells were unable to perform state transitions in the absence of ApcD.The apcD mutant grows more slowly in light mainly absorbed by PBS,indicating that ApcD-dependent energy transfer to PSI is required for optimal growth under this condition.The apcD mutant showed normal blue-light induced quenching,suggesting that ApcD is not required for this process and state transitions are independent of blue-light induced quenching.Under nitrogen fixing condition,the growth rates of the wild type and the mutant were the same,indicating that energy transfer from PBS to PSI in heterocysts was not required for nitrogen fixation. 相似文献
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以新鲜的海生红藻多管藻(Polysiphonia urceolata Grev)为材料,通过DEAE-52离子交换层析,Sephadex G-150和Sephacryl S-300凝胶过滤层析纯化制备了2种R-藻红蛋白(R-phycoerythrin,R-PE)PE272-1和PE377-2.两者有非常相似的光谱特性,... 相似文献
6.
研究了人工合成的二元藻胆体模拟复合物(RPC/APC)的时间分辨荧光光谱并运用多指数拟合的方法对数据进行了详细的处理和分析,研究结果证实了能量在RPC和APC之间的传递时间与能量从RPE传递到RPC的时间几乎相等(50ps);除此之外,RPC到APC没有其它能量传递的通道.结果为能量可以从RPE直接传递到APC同时也可以经过RPC传递到APC,RPC作为能量传递的中间受体,在实际的体系中其作用是通过竞争的机制实现的. 相似文献
7.
Pbycobilisomes (PBS) are able to transfer absorbed energy to photosystem Ⅰ and Ⅱ, and the distribution of light energy between two photosystems is regulated by state transitions. In this study we show that energy transfer from PBS to photosystem Ⅰ (PSI) requires ApcD. Cells were unable to perform state transitions in the absence of ApcD. The apcD mutant grows more slowly in light mainly absorbed by PBS, indicating that ApcD-dependent energy transfer to PSI is required for optimal growth under this condition. The apcD mutant showed normal blue-light induced quenching, suggesting that ApcD is not required for this process and state transitions are independent of blue-light induced quenching. Under nitrogen fixing condition, the growth rates of the wild type and the mutant were the same, indicating that energy transfer from PBS to PSI in heterocysts was not required for nitrogen fixation. 相似文献
8.
The mechanisms of oxygen evolution and carbon fixation in oxygenic organisms depend on the equal distribution of excitation energy to photosystems Ⅰ and Ⅱ, which is regulated by a mechanism referred to as light-state transition. In this work, a novel mechanism, energy spillover from PS Ⅰ to PS Ⅱ referred to as "inverse spillover", was revealed besides "mobile phycobilisome (PBS)" and the "spillover" of energy from PS Ⅱ to PS Ⅰ in cyanobacteria. Under continuous illumination with blue light, time-dependent 77-K fluorescence spectra demonstrated heterogeneous kinetics for the PBS and photosystem components, indicating that inverse spillover and mobile PBS work successively to regulate the excitation to a balanced distribution in cyanobacterial cells under blue light. Inverse spillover and mobile PBS occur under both 100 and 300 μmol m-2 s-1 blue-light conditions but they are accelerated under the latter. 相似文献
9.
Phycobilisomes (PBSs) are the main accessory light-harvesting complexes in cyanobacteria and their movement between photosystems
(PSs) affects cyclic and respiratory electron transport. However, it remains unclear whether the movement of PBSs between
PSs also affects the transthylakoid proton gradient (ΔpH). We investigated the effect of PBS movement on ΔpH levels in a unicellular
cyanobacterium Synechocystis sp. strain PCC 6803, using glycinebetaine to immobilize and couple PBSs to photosystem II (PSII) or photosystem I (PSI) by
applying under far-red or green light, respectively. The immobilization of PBSs at PSII inhibited decreases in ΔpH, as reflected
by the slow phase of millisecond-delayed light emission (ms-DLE) that occurs during the movement of PBSs from PSII to PSI.
By contrast, the immobilization of PBSs at PSI inhibited the increase in ΔpH that occurs when PBSs move from PSI to PSII.
Comparison of the changes in ΔpH and electron transport caused by the movement of PBSs between PSs indicated that the changes
in ΔpH were most likely caused by respiratory electron transport. This will further improve our understanding of the physiological
role of PBS movement in cyanobacteria. 相似文献
10.
不同pH对多变鱼腥藻(Anabaenavariabilis)藻胆体荧光发射光谱,光能传递和解离的影响.在pH7磷酸缓冲溶液中,藻胆体处于稳定状态,不发生解离.在pH6,8,9,10磷酸缓冲溶液中,藻胆体仍处于较稳定状态,没有解离.在pH5,5.5和10.5磷酸缓冲溶液中,藻胆体发生弱解离.在pH4.5缓冲溶液中,藻胆体发生明显解离.在pH4和11缓冲溶液中,藻胆体发生严重解离;藻红蓝蛋白,C-藻蓝蛋白和别藻蓝蛋白所捕获的光能已不能传递给末端发射体 相似文献