title: Inverse Ubbelohde effect in the short hydrogen bond of photosystem II: Relation between H/D isotope effect and symmetry in potential energy profile.
abstract: The short hydrogen bond between tyrosine Yz and D1-His190 of photosystem II (PSII) was investigated using multicomponent quantum mechanics, where the quantum fluctuation of a hydrogen nucleus was incorporated into electronic structure calculation. Our computation demonstrated that the deuteration for hydrogen in the short hydrogen bond of PSII led to the reduction of the O…N distance. It indicated an inverse Ubbelohde effect typically recognized in strong and symmetric hydrogen-bonding clusters such as FHF(-) and H3O2-. We confirmed that the relation between the geometric isotope effect and the symmetry of the potential energy profile of FHF(-) was reasonably agreed with that of PSII. According to this agreement, the short hydrogen bond in PSII can be regarded as a short strong hydrogen bond. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Quantum Chemistry Division, Yokohama City University, Seto 22-2, Kanazawa-Ku, Yokohama, 236-0027, Japan.|Department of biomedical information sciences, Graduate School of Information Sciences, Hiroshima City University, Ozuka-Higashi 3-4-1, Asa-Minami-Ku, Hiroshima, 731-3194, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kanematsu
authors.affiliation: Quantum Chemistry Division, Yokohama City University, Seto 22-2, Kanazawa-Ku, Yokohama, 236-0027, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Tachikawa
authors.affiliation: Department of biomedical information sciences, Graduate School of Information Sciences, Hiroshima City University, Ozuka-Higashi 3-4-1, Asa-Minami-Ku, Hiroshima, 731-3194, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Takano
keywords: geometric H/D isotope effect; inverse Ubbelohde effect; muticomponent quantum mechanics