Study on chemical reaction dynamics in the color determination mechanism in bioluminescence

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05379
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Gunma University (2017); The University of Tokyo (2015-2016)
• Principal Investigator: Hiyama Miyabi 群馬大学, 大学院理工学府, 准教授 (90399311)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: ホタル生物発光 / オキシルシフェリン / 水和 / 量子化学計算 / 分子動力学計算

Outline of Final Research Achievements

We elucidated the vibronic effect on the absorption and fluorescence spectra of the oxyluciferin and its conjugate bases. While the energies of the excited states were calculated with the time-dependent density functional theory, the solvent effect was incorporated using the polarized continuum model. Then, the effects of hydrogen bonding interactions were clarified through a theoretical study on the stability of the oxyluciferin anions with explicit water molecules using the first-principles molecular dynamics (FPMD) simulations. These simulations showed that enol type is more stable than keto type because of the unique features of the static and dynamical hydration structures. The absorption spectra of aqueous oxyluciferin anions were derived using the structures obtained from the FPMD simulations at room temperature for each isomeric form, in order to account for the effects of vibrations of oxyluciferin anions and dynamical fluctuations of their hydration structures.

Free Research Field

物理化学