Williams W P, Salamon Z, Muallem A, Barber J, Mills J
Biochim Biophys Acta. 1976 May 14;430(2):300-11. doi: 10.1016/0005-2728(76)90086-4.
Intact isolated chloroplasts were shown to exhibit a characteristic three-phase pattern of development of oxygen evolution activity. The first phase, Phase I, appeared to be an equilibration phase in which the isolated chloroplasts adapted to the conditions on the electrode surface. It was characterised by a rapidly increasing rate of oxygen evolution accompanied by decreasing enhancement signals. The second phase, Phase II, was an intermediate phase in which the rate of oxygen evolution was maximal and no enhancement was observed. In the last phase, Phase III, the rate of oxygen fell again, normal enhancement was still missing, but the samples appeared to undergo slow adaptive changes closely related to the State I-State II changes previously reported for whole cell systems. The concentrations of Mg2+ within the chloroplast were shown to play an important role in the control of the development of both the oxygen evolution and enhancement signals. It was shown how these signals could be explained in terms of a model that was consistent with that developed in Part I of this investigation to account for the variability of enhancement of the alga Chlorella pyrenoidosa.
完整分离的叶绿体显示出氧气释放活性发展的典型三相模式。第一阶段，即阶段I，似乎是一个平衡阶段，在此阶段分离的叶绿体适应电极表面的条件。其特征是氧气释放速率迅速增加，同时增强信号减弱。第二阶段，即阶段II，是一个中间阶段，在此阶段氧气释放速率最大，未观察到增强现象。在最后一个阶段，即阶段III，氧气释放速率再次下降，仍然没有正常的增强现象，但样品似乎经历了缓慢的适应性变化，这与先前报道的全细胞系统中I态-II态变化密切相关。叶绿体内部Mg2+的浓度在控制氧气释放和增强信号的发展中起着重要作用。展示了如何根据一个模型来解释这些信号，该模型与本研究第一部分中为解释绿藻小球藻增强变化的变异性而建立的模型一致。
