阴离子表面活性剂存在下光系统II中酪氨酸残基的性能研究

通过荧光光谱和富立叶变换红外(FT-IR)光谱研究了阴离子型表面活性剂－十 二烷基硫酸钠（SDS）与光系统II（PSII）的相互作用。结果表明，PSII表现出酪 氨酸荧光的特性。在PSII蛋白质内部，存在着232 nm处的组分与酪氨酸之间以及这 两种氨基酸列基与叶绿素a之间的能量传递。SDS的存在会使这些能量传递以及 PSII中蛋白的骨架结构和酪氨酸残基的结构发生改变，而变化方式又明显受SDS在 溶液中聚集状态的影响。低于其临界胶束浓度(cmc)时，SDS会促进蛋白质中232 nm外的组分与酪氨酸之间的能量传递，并且使酪氨酸残基外于极性更小的环境； 而大于cmc时，SDS却产生相反的效应。但不同浓度的SDS均会抑制酪氨酸残基至叶 绿素a的能量传递。

Studies on Properties of Tyrosyl Residues in Photosystem II in the Presence of Anionic Surfactant

The interaction of anionic surfactant sodium dodecyl sulfate (SDS) with photosystem II (PS II) was studied by ultraviolet (UV)absorption, fluorescence and Fourier transform infrared (FT-IR) spectroscopy. It was found that PS II was characteristics of tyrosyl residue fluorescence. The results have shown that there exist excitation energy transfers from the component at 232 nm in PS II proteins to the tyrosyl residues, and from these two amino acid residues to chlorophyll a. The effect of SDS on PS II caused the changes in these energy transfers, and also given rise to the changes in structural aspects of PS II protein skeleton and tyrosyl residues, which was dependent on the aggregate state of SDS molecules in solution. Below its critical micelle concentration (cmc), SDS effect facilitated the energy transfer from the component at 232 nm to the tyrosyl residues in PS II proteins, and also resulted in less micropolarity for tyrosyl residues, whilst at or above its cmc, SDS had an opposite effect. However, SDS exhibited an inhibition of the energy transfer from tyrosine residues to chlorophyll a, regardless of SDS concentration.