Absorption Spectra for Firefly Bioluminescence Substrate Analog: TokeOni in Various pH Solutions
Absorption Spectra for Firefly Bioluminescence Substrate Analog: TokeOni in Various pH Solutions
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DOI：
10.1111/php.13458
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发表时间：
2021-06
影响因子：
3.3
通讯作者：
Haruhisa Ogawa;Ryohei Ono;Y. Noguchi;Nobuo Kitada;Ryohei Saito-Moriya;S. Maki;H. Akiyama;H. Itabashi;Miyabi Hiyama
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文献类型：
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作者：
Haruhisa Ogawa;Ryohei Ono;Y. Noguchi;Nobuo Kitada;Ryohei Saito-Moriya;S. Maki;H. Akiyama;H. Itabashi;Miyabi Hiyama
AkaLumine hydrochloride，名为TokeOni，是萤火虫荧光素类似物之一，它与萤火虫荧光素酶反应产生近红外（NIR）生物发光。在研究生物发光机制之前，必须获得有关TokeOni在不同pH值溶液中的化学结构，电子状态和吸收特性的基本知识。本文测定了TokeOni和AkaLumine在pH 2-10范围内的吸收光谱。进行密度泛函理论（DFT）计算、时间依赖性DFT计算和振动分析。吸收光谱表明，TokeOni在溶液中的化学形式与AkaLumine相同。吸收光谱中pH 7-10处的峰对应于AkaLumine的羧酸根阴离子的基态激发，pH 2处的峰对应于AkaLumine的具有N-质子化噻唑啉环和N-质子化二甲氨基的羧酸根阴离子的基态激发，pH 4处的峰对应于具有AkaLumine的N-质子化噻唑啉环的羧酸根阴离子的基态激发。
AkaLumine hydrochloride, named TokeOni, is one of the firefly luciferin analogs, and its reaction with firefly luciferase produces near‐infrared (NIR) bioluminescence. Prior to studying the bioluminescence mechanism, basic knowledge about the chemical structures, electronic states, and absorption properties of TokeOni at various pH values of solution has to be acquired. In this paper, the absorption spectra for TokeOni and AkaLumine at pH 2–10 were measured. Density functional theory (DFT) calculations, time‐dependent DFT calculations, and the vibrational analyses were carried out. The absorption spectra indicate that the chemical forms of TokeOni in solutions are same as those of AkaLumine. The peaks at pH 7–10 in the absorption spectra correspond to the excitation from the ground state of a carboxylate anion of AkaLumine, the peak at pH 2 corresponds to the excitation from the ground state of a carboxylate anion with an N‐protonated thiazoline ring and N‐protonated dimethylamino group of AkaLumine, and the peak at pH 4 corresponds to the excitation from the ground state of a carboxylate anion with an N‐protonated thiazoline ring of AkaLumine.