Slooten L, Branders C
Biochim Biophys Acta. 1979 Jul 10;547(1):79-90. doi: 10.1016/0005-2728(79)90097-5.
(1) Chromatophores were preilluminated in the presence of phenazine methosulphate or diaminodurene, and without phosphorylation substrates; next they were transferred to fresh medium and assayed for light-induced proton uptake, light-induced 9-aminoacridin fluorescence quenching, and photophosphorylation. (2) Preillumination in the presence of phenazine methosulphate or diaminodurene causes an inhibition of the photophosphorylation rate. The presence of ADP + MgCl2 + phosphate, or ADP + MgCl2 + arsenate during preillumination provides full protection against this effect. (3) Preilluminated chromatophores are leaky for protons. The leak is expressed as an accelerated dark decay, and a diminished extent of succinate-supported, light-induced proton uptake. The extent of light-induced 9-aminoacridin fluorescence quenching is also diminished. (4) The proton leak can be closed by oligomycin and by dicyclohexyl carbodiimide (at concentrations similar to those used to inhibit photophosphorylation), but not by aurovertin. Closure of the proton leak results in partial restoration of the photophosphorylation rate. (5) The inhibition of phosphorylation by oligomycin or dicyclohexyl carbodiimide is time-dependent. In untreated chromatophores, the time-dependence is determined by the extent of membrane energization. In preilluminated chromatophores, the time-dependence is determined in addition by the extent to which the proton leaks have been closed. The reasons for this are briefly discussed.
(1) 载色体在存在吩嗪硫酸甲酯或二氨基杜烯且无磷酸化底物的情况下进行预光照；接下来将它们转移到新鲜培养基中，并检测光诱导的质子摄取、光诱导的9-氨基吖啶荧光猝灭和光合磷酸化。(2) 在吩嗪硫酸甲酯或二氨基杜烯存在下的预光照会导致光合磷酸化速率受到抑制。预光照期间存在ADP + MgCl2 + 磷酸盐或ADP + MgCl2 + 砷酸盐可完全防止这种效应。(3) 预光照的载色体对质子有泄漏现象。这种泄漏表现为暗衰变加速以及琥珀酸支持的光诱导质子摄取程度降低。光诱导的9-氨基吖啶荧光猝灭程度也降低。(4) 质子泄漏可被寡霉素和二环己基碳二亚胺（浓度与用于抑制光合磷酸化的浓度相似）封闭，但不能被金盏花素封闭。质子泄漏的封闭导致光合磷酸化速率部分恢复。(5) 寡霉素或二环己基碳二亚胺对磷酸化的抑制作用是时间依赖性的。在未处理的载色体中，时间依赖性由膜去极化程度决定。在预光照的载色体中，时间依赖性还由质子泄漏被封闭的程度决定。对此原因进行了简要讨论。
