单体和二聚体形式的叶绿体细胞色素 b6f 复合物的功能活动。

Functional activities of monomeric and dimeric forms of the chloroplast cytochrome b6f complex.

机构信息

Department of Plant Biology, University of California Berkeley, 111 Koshland Hall, 94720-3102, CA, USA.

出版信息

Photosynth Res. 1995 Jan;46(3):419-26. doi: 10.1007/BF00032296.

Abstract

A monomeric form of the isolated cytochrome b6f complex from spinach chloroplast membranes has been isolated after treatment of the dimeric complex with varying concentrations of Triton X-100. The two forms of the complex are similar as regards electron transfer components and subunit composition. In contrast to a previous report (Huang et al. (1994) Biochemistry 33: 4401-4409) both the monomer and dimer are enzymatically active. However, after incorporation of the respective complexes into phospholipid vesicles, only the dimeric form of the cytochrome complex shows uncoupler sensitive electron transport, an indication of coupling of electron transport to proton translocation. The absence of this activity with the monomeric form of the cytochrome complex may be related to an inhibition by added lipids.

摘要

用不同浓度的 Triton X-100 处理二聚体复合物后，从菠菜叶绿体膜中分离出单体形式的细胞色素 b6f 复合物。这两种形式的复合物在电子传递成分和亚基组成方面相似。与之前的报道（Huang 等人，（1994）生物化学 33:4401-4409）相反，单体和二聚体都是具有酶活性的。然而，将相应的复合物掺入磷脂囊泡后，只有细胞色素复合物的二聚体形式显示解偶联剂敏感的电子传递，这表明电子传递与质子转运相偶联。单体形式的细胞色素复合物没有这种活性，可能与添加的脂质的抑制作用有关。