著者

斉藤 圭亮 石北 央

出版者

一般社団法人 植物化学調節学会

雑誌

植物の生長調節 (ISSN:13465406)

巻号頁・発行日

vol.50, no.2, pp.133-138, 2015-12-21 (Released:2017-09-29)

参考文献数

11

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We investigated the degrees of chlorin ring deformations of the special pair chlorophylls P_<D1>/P_<D2> in the Photosystem II (PSII) crystal structure, using a quantum mechanical/molecular mechanical approach. We found that (i) the out-of-plane distortion of the PD1 chlorin ring can be described predominantly by a large "doming mode" arising from the axial ligand D1-His198. In contrast, (ii) the deformation of PD2 was caused by a "saddling mode" arising from the D2-Trp191 side chain and the axial ligand D2-His197. However, (iii) the redox potential difference between P_<D1> and P_<D2> was predominantly determined by the PSII electrostatic environment rather than by the degree of the chlorin-ring distortion. (iv) The chlorin ring deformation appears to simply originate from the local steric protein environment of PSII.