Reed D W, Zankel K L, Clayton R K
SECTION OF GENETICS, DEVELOPMENT, AND PHYSIOLOGY, ITHACA, NEW YORK.
Proc Natl Acad Sci U S A. 1969 May;63(1):42-6. doi: 10.1073/pnas.63.1.42.
We have prepared photosynthetic reaction centers from Rhodopseudomonas spheroides and have studied the fluorescence of the photochemical electron donor, P870. The yield of this fluorescence rises at low redox potential, presumably because the photochemical electron acceptor becomes reduced and the photochemical utilization of excitation energy is then prevented. The redox titration curve for this increase in the fluorescence has a shape corresponding to the transfer of one electron. The midpoint potential is -0.05 volt, independent of the pH from 6.5 to 8.8. The amplitude of a light-induced absorbance change at 280 nanometers varies with redox potential and shows, at pH 7.5, a midpoint potential of 0.00 volt. These studies indicate that the primary photochemical electron acceptor is not ubiquinone and is not the substance responsible for the absorbance change at 280 nanometers.
我们已经制备了来自球形红假单胞菌的光合反应中心,并研究了光化学电子供体P870的荧光。这种荧光的产率在低氧化还原电位下会升高,大概是因为光化学电子受体被还原,从而阻止了激发能的光化学利用。荧光增加的氧化还原滴定曲线的形状对应于一个电子的转移。中点电位为-0.05伏,在pH值6.5至8.8范围内与pH无关。在280纳米处光诱导吸光度变化的幅度随氧化还原电位而变化,在pH 7.5时,中点电位为0.00伏。这些研究表明,初级光化学电子受体不是泛醌,也不是负责280纳米处吸光度变化的物质。