2024-03-29T02:06:05Z
https://repository.dl.itc.u-tokyo.ac.jp/oai
oai:repository.dl.itc.u-tokyo.ac.jp:00000707
2022-12-19T03:41:42Z
30:31
9:10:11
Energetics of proton release on the first oxidation step in the water-oxidizing enzyme
Saito, Keisuke
2620
Rutherford, A. William
2621
Ishikita, Hiroshi
2622
Chemical sciences
Biochemistry
Biophysics
In photosystem II (PSII), the Mn4CaO5 cluster catalyses the water splitting reaction. The crystal structure of PSII shows the presence of a hydrogen-bonded water molecule directly linked to O4. Here we show the detailed properties of the H-bonds associated with the Mn4CaO5 cluster using a quantum mechanical/molecular mechanical approach. When O4 is taken as a μ-hydroxo bridge acting as a hydrogen-bond donor to water539 (W539), the S0 redox state best describes the unusually short O4–OW539 distance (2.5 Å) seen in the crystal structure. We find that in S1, O4 easily releases the proton into a chain of eight strongly hydrogen-bonded water molecules. The corresponding hydrogen-bond network is absent for O5 in S1. The present study suggests that the O4-water chain could facilitate the initial deprotonation event in PSII. This unexpected insight is likely to be of real relevance to mechanistic models for water oxidation.
UTokyo Research掲載「光合成の水分解反応初期に水素イオンが放出される仕組みを解明」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/pathway-for-initial-proton-released-from-water-oxidizing-enzyme.html
UTokyo Research "Pathway for initial proton released from water-oxidizing enzyme" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/pathway-for-initial-proton-released-from-water-oxidizing-enzyme.html
journal article
Nature Publishing Group
2015-10-07
application/pdf
Nature communications
6
8488
AA12645905
20411723
https://repository.dl.itc.u-tokyo.ac.jp/record/707/files/ncomms9488.pdf
eng
info:doi/10.1038/ncomms9488
http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/pathway-for-initial-proton-released-from-water-oxidizing-enzyme.html
http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/pathway-for-initial-proton-released-from-water-oxidizing-enzyme.html
http://www.nature.com/ncomms/2015/151007/ncomms9488/abs/ncomms9488.html
Copyright © 2015, Rights Managed by Nature Publishing Group