Mechanism of nano-anatase TiO2 on promoting photosynthetic carbon reaction of spinach -: Inducing complex of Rubisco-Rubisco activase
Mechanism of nano-anatase TiO2 on promoting photosynthetic carbon reaction of spinach -: Inducing complex of Rubisco-Rubisco activase
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DOI：
10.1385/bter:111:1:239
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发表时间：
2006-06-01
影响因子：
3.9
通讯作者：
Yang, Ping
中科院分区：
文献类型：
--
作者：
Gao, Fengqing;Hong, Fashui;Yang, Ping
纳米锐钛矿型TiO2具有光催化特性，我们前期的研究已经证明其与菠菜的光合作用密切相关。它不仅可以提高菠菜的光吸收率和光能向电子能和活性化学能的转化，而且可以促进菠菜二氧化碳（CO2）的同化。然而，纳米锐钛矿型TiO2促进碳反应的机制仍不清楚。通过电泳和Western blot方法，实验结果证明，在Rubisco提取过程中，纳米锐钛矿TiO2处理的菠菜中的Rubisco由Rubisco和包含Rubisco和Rubisco激活酶的较重分子量蛋白（约1200 kDa）组成。 Rubisco羧化酶活性是对照Rubisco的2.67倍，并且能够以与Rubisco激活酶相同的方式水解ATP。 Rubisco 的总巯基和有效巯基分别比从对照纯化的 Rubisco 多每摩尔酶 32-SH 和 21-SH。圆二色光谱表明，经纳米锐钛矿TiO2处理的菠菜中的Rubisco的二级结构与对照的Rubisco有很大不同。表明纳米锐钛矿TiO2激活菠菜Rubisco的机制是在菠菜中诱导Rubsico与Rubisco激活酶的复合物，促进Rubsico羧化，提高光合碳反应速率。
Having a photocatalyzed characteristic, our previous research had proved that nano-anatase TiO2 is closely related to the photosynthesis of spinach. It could not only improve the light absorbance and the transformation from light energy to electron energy and to active chemical energy but also promote carbon dioxide (CO2) assimilation of spinach. However, the mechanism of carbon reaction promoted by nano-anatase TiO2 remains largely unclear. By electrophoresis and Western blot methods, the results of the experiments proved that Rubisco from the nano-anatase TiO2-treated spinach during the extraction procedure of Rubisco was found to consist of Rubisco and a heavier molecular-mass protein (about 1200 kDa) comprising both Rubisco and Rubisco activase. The Rubisco carboxylase activity was 2.67 times that of Rubisco from the control and it could hydrolyze ATP in the same manner as Rubisco activase. The total sulfhydryl groups and available sulfhydryl groups of the Rubisco were 32-SH and 21-SH per mole of enzyme more than those of the Rubisco purified from the control, respectively. The circular dichroism spectra showed that the secondary structure of Rubisco from the nano-anatase TiO2-treated spinach was very different from Rubisco of the control. It suggested that the mechanism of nano-anatase TiO2 activating Rubisco of spinach was that the complex of Rubsico and Rubisco activase was induced in spinach, which promoted Rubsico carboxylation and increased the rate of photosynthetic carbon reaction.