Mulkidjanian A Y, Junge W
Biophysik, Fachbereich Biologie/Chemie, Universität Osnabrück, Germany.
FEBS Lett. 1994 Oct 17;353(2):189-93. doi: 10.1016/0014-5793(94)01031-5.
The flash-induced proton release into the lumen of chromatophores from Rhodobacter capsulatus was studied with Neutral red as pH-indicator. Calibration of the acidification jump after a single flash yielded a much larger figure, at least 0.8 units, than previously thought. A slow kinetic phase of proton release (85-90% of total) was sensitive to inhibitors of the cytochrome bc1-complex. Its half-rise time, about 10 ms, was the same as the rise time of the electrogenic reaction in the cytochrome bc1-complex that was recorded by electrochromism of carotenoids. The oxidoreduction of the two b-hemes was significantly faster (t1/2 approximately equal to 3 ms). Thus the major electrogenic event in the cytochome bc1-complex is proton and not electron transfer.
以中性红作为pH指示剂，研究了闪光诱导的质子从荚膜红细菌的载色体释放到内腔中的过程。单次闪光后酸化跃变的校准得出的数值比之前认为的要大得多，至少为0.8个单位。质子释放的缓慢动力学阶段（占总量的85%-90%）对细胞色素bc1复合体的抑制剂敏感。其半上升时间约为10毫秒，与通过类胡萝卜素的电致变色记录的细胞色素bc1复合体中电化学反应的上升时间相同。两个b-血红素的氧化还原明显更快（半衰期约为3毫秒）。因此，细胞色素bc1复合体中的主要电化学反应是质子转移而非电子转移。
