突变体大麦Mb1832C的叶绿素蛋白复合体

The Gel Protein Complexes of a Mutant Barley Mb1832C

用低浓度ＳＤＳ对突变体大麦Ｍｂ１８３２Ｃ的类囊体膜进行增溶，再经不连续的ＳＤＳ聚丙烯酰胺凝胶电泳后，按电泳迁移率的增加顺序，分离出ＣＰＩ，ＣＰａｌ，ＣＰａ２和ＦＣ４条蓝绿色的带。ＣＰＩ在红区和蓝区的吸收峰分别位于６７７ｎｍ和４３８ｎｍ处。低温荧光发射光谱表明ＣＰＩ为含有少量光系统ＩＩ的光系统Ｉ反应中心复合体。ＣＰａ１和ＣＰａ２的光谱性质相似。它们的红峰和蓝峰的位置分别位于６７２ｎｍ和４３６ｎｍ处。它们在７７Ｋ的荧光发射峰都位于６８５ｎｍ的事实证明ＣＰａ１和ＣＰａ２都属于光系统ＩＩ。上述结果表明该突变体大麦包含有３种叶绿素ａ蛋白复合体ＣＰＩ，ＣＰａｌ和ＣＰａ２，而不含任何捕光叶绿素ａ／ｂ蛋白复合体。Ｍｂ１８３２Ｃ为一新的缺失叶绿素ｂ，但能独立生存的大麦突变体。

When the mutant barley Mb1832C thylakoid membranes were solubilized at a lower SDS concentration and subjected to discontinuous SDS PAGE at 4 ℃, 4 blue green bands were resolved. The resolved bands in order of increasing mobility were CPI,CPa1,CPa2 and FC. CPI had absorption peaks at 677 nm in the red region and at 438 nm in the blue region. Low temperature fluorescence emission spectrum showed that it is photosystem I reaction center complex containing less photosystem II. The spectral properties of CPa1 and CPa2 were similar. They had a red absorption maximum at 672 nm and a blue one at 436 nm. Their fluorescence emission peaks at 77 K were at 685 nm, indicating that they belong to photosystem II. The results in this paper indicate that the mutant barley only contains 3 chl a protein complexes: CPI,CPa1 and CPa2. It totally lacks any light harvesting chl a/b protein complexes. Therefore, Mb1832C is a new type of chl b less mutant and can survive independently in nature.