Liang Chen, Xiao Wu, Hao Huang, Xiaoqing Liu, Chao Liu, Lei Zheng, Fashui Hong
Medical College of Suzhou University, Suzhou 215123, People's Republic of China.
Spectrochim Acta A Mol Biomol Spectrosc. 2009 Mar;72(2):343-7. doi: 10.1016/j.saa.2008.10.012. Epub 2008 Oct 25.
In the present paper we report the results obtained with the photosystem II (PSII) isolated from spinach treated by MgCl(2), and studied the effect of Mg(2+) on spectral characteristics and photosynthetic functions of PSII. The results showed that Mg(2+) treatment at a suitable concentration could significantly increase the absorption intensity of PSII and the intensity ratio of Soret band to Q band of chlorophyll-a. The treatment also elevated the excited peak intensity at 230, 278 and 343 nm, and the emitted peak intensity at 304 and 682 nm, and the ratio of F(278)/F(230), respectively. The results implied that Mg(2+) increased absorbance for visible light, improving energy transfer among amino acids within PSII protein complex and accelerating energy transport from tyrosine residue to chlorophyll-a. The photochemical activity and oxygen evolving rate of PSII were also enhanced by Mg(2+). This is viewed as evidence that Mg(2+) can promote energy transfer and oxygen evolution in PSII of spinach.
在本文中，我们报告了用MgCl₂处理从菠菜中分离出的光系统II（PSII）所获得的结果，并研究了Mg²⁺对PSII光谱特性和光合功能的影响。结果表明，适宜浓度的Mg²⁺处理可显著提高PSII的吸收强度以及叶绿素a的Soret带与Q带的强度比。该处理还分别提高了230、278和343nm处的激发峰强度，304和682nm处的发射峰强度，以及F(278)/F(230)的比值。结果表明，Mg²⁺增加了对可见光的吸收，改善了PSII蛋白复合物内氨基酸之间的能量转移，并加速了从酪氨酸残基到叶绿素a的能量传递。Mg²⁺还增强了PSII的光化学活性和放氧速率。这被视为Mg²⁺可促进菠菜PSII中能量转移和氧气释放的证据。
