Comparative Analysis of the Interaction of the Primary Quinone Q(A) in Intact and Mn-Depleted Photosystem II Membranes Using Light-Induced ATR-FTIR Spectroscopy

作者：Kato Yuki^*; Ishii Rina; Noguchi Takumi^*

来源：Biochemistry, 2016, 55(46): 6355-6358.

DOI：10.1021/acs.biochem.6b01052

In photosystem II, redox potential E-m of primary quinone Q(A) shifts by approximately +150 mV upon inactivation of the Mn4CaO5 cluster. Although this phenomenon is important in photoprotection, the molecular mechanism of the positive E-m(Q(A)(-)/Q(A)) shift remains unclear. Here, we investigated the effect of Mn depletion on the interaction of Q(A) using light-induced ATR-FTIR spectroscopy. It was shown that Mn depletion hardly changed a Q(A)(-)/Q(A) FTIR difference spectrum, indicating that the H-bond interaction of Q(A) and its immediate surroundings were virtually unchanged by Mn4CaO5 cluster inactivation. On the basis of this result, a possible mechanism of the E-m(Q(A)(-)/Q(A)) shift is discussed.

• 出版日期2016-11-22