Heathcote P, Moënne-Loccoz P, Rigby S E, Evans M C
School of Biological Sciences, Queen Mary and Westfield College, University of London, U.K.
Biochemistry. 1996 May 28;35(21):6644-50. doi: 10.1021/bi9526185.
Previous work has challenged the assignment of a photoaccumulated EPR signal to the phylloquinone electron acceptor in photosystem I, A1.-. Biosynthetic deuteration of the phylloquinone in the cyanobacterium Anabaena variabilis has been shown to narrow this photoaccumulated signal, demonstrating that the signal arises from A1.-. The ESP signal attributed to P700.+A1.- is also narrowed by this deuteration, showing that the photoaccumulated EPR signal and the ESP signal are monitoring the same redox component. Confirmation that the photoaccumulated EPR signal comes from deuterated phylloquinone was obtained by exchanging the deuterated for protonated phylloquinone, which broadened the photoaccumulated EPR signal.
先前的研究对光系统I中光积累的电子顺磁共振（EPR）信号归属于叶绿醌电子受体A1提出了质疑。已证明，对多变鱼腥藻中的叶绿醌进行生物合成氘代可使该光积累信号变窄，这表明该信号源自A1。这种氘代也使归因于P700 + A1的电子自旋极化（ESP）信号变窄，表明光积累的EPR信号和ESP信号监测的是同一氧化还原成分。通过将氘代叶绿醌换成质子化叶绿醌，使光积累的EPR信号变宽，从而证实了光积累的EPR信号来自氘代叶绿醌。
