突变的叶绿体ATP合成酶ε亚基对菠菜叶绿体毫秒延迟发光的影响  

Effect of Mutated ε Subunit of Chloroplast ATP Synthase on the Fast Phase of the Millisecond Delayed Light Emission in Spinach Chloroplast

作　　者：石晓冰[1] 史瑾[1] 沈允钢[1] 

机构地区：[1]中国科学院上海植物生理研究所,上海200032

出　　处：《植物生理学报（0257-4829)》1999年第3期244-248,共5页Acta Phytophysiologica Sinica

基　　金：国家自然科学基金;国家重点研究发展规划资助

摘　　要：突变和野生型叶绿体ＡＴＰ 合成酶的ε亚基均可增强叶绿体毫秒延迟发光的快相；不同的突变体对快相的增强强度不同，但与它们对离体ＣＦ１ 的Ｃａ２＋ＡＴＰ酶水解活力的抑制程度情况一致。且这种影响在１ ℃左右的低温下较显著，而温度升至２５ ℃时，这种增强作用趋于消失。加入解联剂后，快相部分消除，ε亚基仍有增强作用。这些结果说明，ε亚基是通过与ＣＦ１ 的专一作用而影响光系统Ⅱ附近类囊体膜的动态结构， 使质子不易从类囊体膜上流失。By studying the enhancing effect of the mutated ε subunit of ATP synthase on the fast phase of millisecond delayed light emission (ms DLE) in spinach chloroplast, the specific interaction between the ε subunit and the CF 1 part of ATP synthase was confirmed. Both the ε subunit of the wild type and the mutants enhanced the fast phase of ms DLE (Fig.1A). The mutants ε T42R (substitute Thr 42 with Arg) and ε T42C (substitute Thr 42 with Cys) enhanced the fast phase of ms DLE slightly higher than the ε subunit of the wild type, and the mutant εT42I (substitute Thr 42 with Ile) enhanced it in a higher degree. These results were consistent with the degree of inhibitory effect on the activity of Ca + ATPase by these mutants of ε subunit. The enhancement of the fast phase of ms DLE was obvious at a low temperature of 1℃ (Fig.1), while it was decreased at 25℃ (Fig.2). It suggests that the ε subunit interacts with the CF 1 specifically, and this interaction could change the dynamic structure of the thylakoid membranes near the photosystem Ⅱ at low temperature, which makes it more difficult for the protons to leak out through the membrane.

关 键 词：叶绿体 毫秒延迟发光 ATP合成酶 Ε亚基 

分 类 号：Q945.11[生物学—植物学]