对光系统II和类囊体膜中细胞色素b559化学计量学的重新评估。

Reevaluation of the stoichiometry of cytochrome b559 in photosystem II and thylakoid membranes.

作者信息

Buser C A, Diner B A, Brudvig G W

机构信息

Department of Chemistry, Yale University, New Haven, Connecticut 06511.

出版信息

Biochemistry. 1992 Nov 24;31(46):11441-8. doi: 10.1021/bi00161a024.

DOI:10.1021/bi00161a024

PMID:1332760

Abstract

The stoichiometry of cytochrome b559 (one or two copies) per reaction center of photosystem II (PSII) has been the subject of considerable debate. The molar ratio of cytochrome b559 has a number of significant implications on our understanding of the functional role of cytochrome b559, the mechanism of electron donation in PSII, and the stoichiometry of the other redox-active, reaction center components. We have reinvestigated the stoichiometry of cytochrome b559 in PSII-enriched and thylakoid membranes, using differential absorbance and electron paramagnetic resonance spectroscopies. The data from both quantitation procedures strongly indicate only one copy of cytochrome b559 per reaction center in PSII-enriched membranes and also suggest one copy of cytochrome b559 per reaction center in thylakoid membranes.

摘要

细胞色素b559在光系统II（PSII）每个反应中心的化学计量比（一个或两个拷贝）一直是大量争论的主题。细胞色素b559的摩尔比对于我们理解细胞色素b559的功能作用、PSII中的电子供体机制以及其他氧化还原活性反应中心组分的化学计量比具有许多重要意义。我们使用差分吸收光谱和电子顺磁共振光谱，重新研究了富集PSII的膜和类囊体膜中细胞色素b559的化学计量比。两种定量方法的数据都强烈表明，在富集PSII的膜中，PSII每个反应中心只有一个细胞色素b559拷贝，并且也表明类囊体膜中每个反应中心有一个细胞色素b559拷贝。