期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1971
卷号：68
期号：12
页码：3064-3068
DOI：10.1073/pnas.68.12.3064
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Spinach chloroplasts were found to contain three forms of cytochrome b559 that have the same -peak at 559 nm, but are distinguished from one another by their oxidation-reduction potentials. The high-potential (H) form (Em about 330-350 mV) is reducible by hydroquinone, the middle-potential (M) form (Em about 50-80 mV) is reducible by ascorbate but not by hydroquinone, and the low-potential (L) form is reducible by dithionite but not by ascorbate. The H form was the predominant one in freshly prepared chloroplasts and was strongly correlated with Photosystem II activity. Chloroplast treatments such as aging, sonication, and mild heating, singly or in combination, brought about a shift of the H to the M form. More drastic treatments resulted in shifts of the H and M forms to the L form. The role of cytochrome b559 as an electron carrier in System II of plant photosynthesis is discussed.
关键词：electron carriers ; redox potential ; light-induced electron transport ; spinach
