Electron transfer in the heliobacterial reaction center:: evidence against a quinone-type electron acceptor functioning analogous to A1 in photosystem I
Electron transfer in the heliobacterial reaction center:: evidence against a quinone-type electron acceptor functioning analogous to A1 in photosystem I
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DOI：
10.1016/s0005-2728(98)00010-3
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发表时间：
1998-03-25
影响因子：
4.3
通讯作者：
Liebl, U
中科院分区：
文献类型：
--
作者：
Brettel, K;Leibl, W;Liebl, U
利用时间分辨光谱和光电压测量对运动太阳杆菌（Heliobacillus mobilis）的膜碎片进行了表征，以检测甲基萘醌（MQ）作为电子从初级受体A（0）转移到光合反应中心的铁硫簇F-X的中间体的可能参与，其功能类似于光系统I中的叶绿醌A（1）。获得的光谱数据排除了电子从半醌阴离子MQ（-）到F-X的转移发生在从2 ns到4 μ S的时间窗口内，在那里它将被预期类似于光系统I。在F-X预还原的情况下，仅形成初级对P798（+）A（0）。光电压数据产生了一个单一的动力学阶段，时间常数为700 ps的跨膜电子转移超过A（0）;该阶段的相对振幅表明，它反映了电子转移从A（0）（-）到FX。(C)出版社：Elsevier Science B. V.
Membrane fragments from Heliobacillus mobilis were characterized using time resolved optical spectroscopy and photovoltage measurements in order to detect a possible participation of menaquinone (MQ), functioning analogous to the phylloquinone A(1) in photosystem I, as intermediate in electron transfer from the primary acceptor A(0) to the iron-sulfur cluster F-X in the photosynthetic reaction center. The spectroscopic data obtained exclude that electron transfer from a semiquinone anion MQ(-) to F-X occurred in the time window from 2 ns to 4 mu S, where it would be expected in analogy to photosystem I. In the case of a prereduction of F-X, only the primary pair P798(+)A(0) was formed. The photovoltage data yielded a single kinetic phase with a time constant of 700 ps for the transmembrane electron transfer beyond A(0); the relative amplitude of this phase suggests that it reflects electron transfer from A(0)(-) to FX. (C) 1998 Published by Elsevier Science B.V.