@article{oai:nagoya.repo.nii.ac.jp:00030516, author = {Taguchi, Shota and Shen, Liangliang and Han, Guangye and Umena, Yasufumi and Shen, Jian-Ren and Noguchi, Takumi and Mino, Hiroyuki}, issue = {20}, journal = {The Journal of Physical Chemistry Letters}, month = {Oct}, note = {The high-spin S2 state was investigated with photosystem II (PSII) from spinach, Thermosynechococcus vulcanus, and Cyanidioschyzon merolae. In extrinsic protein-depleted PSII, high-spin electron paramagnetic resonance (EPR) signals were not detected in either species, whereas all species showed g ∼ 5 signals in the presence of a high concentration of Ca^2+ instead of the multiline signal. In the intact and PsbP/Q-depleted PSII from spinach, the g = 4.1 EPR signal was detected. These results show that formation of the high-spin S2 state of the manganese cluster is regulated by the extrinsic proteins through a charge located near the Mn4 atom in the Mn4CaO5 cluster but is independent of the intrinsic proteins. The shift to the g ∼ 5 state is caused by tilting of the z-axis in the Mn4 coordinates through hydrogen bonds or external divalent cations. The structural modification may allow insertion of an oxygen atom during the S2-to-S3 transition., Published online: 29 September 2020 ファイル公開:2021-09-29}, pages = {8908--8913}, title = {Formation of the High-Spin S2 State Related to the Extrinsic Proteins in the Oxygen Evolving Complex of Photosystem II}, volume = {11}, year = {2020} }