细菌生物发光体的理论研究
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- 英文论文题名：Theoretical Study on Assigning Bacterial Bioluminophore
- 论文作者：罗艳玲 ; 刘亚军
- 英文论文作者：Yanling Luo ; Ya-Jun Liu ; College of Chemistry ; Beijing Normal University
- 年：2016
- 作者机构：北京师范大学化学学院;
- 论文关键词：细菌生物发光体 ; 荧光猝灭 ; MS-CASPT2 ; QM/MM
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十八分会：电子结构理论方法的发展与应用
- 语种：中文
- 分类号：Q93
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十八分会 ; 电子结构理论方法的发展与应用
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：113k
- 原文格式：D
- 会议级别：全国
摘要
发光细菌是自然界中广泛分布的生物发光物种,具有连续性发光的特点,被应用到环境毒性检测、生物传感器及体内显像等重要领域。对细菌生物发光反应的研究已有半世纪之久,但仍存在一些问题尚未完全解决,其中包括细菌生物发光体的指认。细菌发光反应终产物黄素单核苷酸FMN最初被认为是发光体的可能结构,后中间体羟基取代黄素单核苷酸HFOH为发光体的猜想被提出,二者具有相似的分子结构和荧光波长。然而实验和理论研究结果更倾向于后者~([1-2]),HFOH在溶液中不发光,但在细菌荧光素酶中为强的荧光发色团;FMN恰恰相反,当与蛋白结合后其荧光被猝灭,但对FMN在细菌荧光素酶中荧光猝灭机理的理论研究从未见报道。为了进一步确认发光体结构和探究FMN荧光猝灭现象,本文在原来研究基础上~([2]),采用多参考态组态二阶微扰理论方法 MS-CASPT2,同时结合QM/MM和MD考虑蛋白环境和涨落的影响。计算结果证实第一单重激发态的HFOH为细菌生物发光体,同时说明荧光素酶中的络氨酸-110为FMN荧光的主要猝灭剂。
The Assigning of bacterial bioluminophore is of prime importance to developing its applications and follow-up mechanism researches.The final product FMN and postulated intermediate HFOH are both assumed as candidates for light emitter.Currently, the latter is palatable via experimental and our DFT computational studies.HFOH displays weak fluorescence in solutions, but exhibits strong bioluminescence in bacterial luciferase.Whereas, FMN is just in the opposite way, whose fluorescence is quenched when bounded to the protein.The paucity of strong evidence makes it confusing to explain the quenching reason.To further confirm the real light emitter and investigate fluorescence quench phenomenon, a MS-CASPT2 calculation is performed together with QM/MM and MD methods to consider the protein effect.The computational results validate that the S_1 HFOH is the bioluminophore of bacteria, and imply that the tyrosine-110 in luciferase acts as the quencher for FMN fluorescence.
The Assigning of bacterial bioluminophore is of prime importance to developing its applications and follow-up mechanism researches.The final product FMN and postulated intermediate HFOH are both assumed as candidates for light emitter.Currently, the latter is palatable via experimental and our DFT computational studies.HFOH displays weak fluorescence in solutions, but exhibits strong bioluminescence in bacterial luciferase.Whereas, FMN is just in the opposite way, whose fluorescence is quenched when bounded to the protein.The paucity of strong evidence makes it confusing to explain the quenching reason.To further confirm the real light emitter and investigate fluorescence quench phenomenon, a MS-CASPT2 calculation is performed together with QM/MM and MD methods to consider the protein effect.The computational results validate that the S_1 HFOH is the bioluminophore of bacteria, and imply that the tyrosine-110 in luciferase acts as the quencher for FMN fluorescence.
引文
[1]Lei,B.F.;Ding,Q.Z.;Tu,S.C.Biochem.2004,43,15975.
[2]Hou,C.;Liu,Y.-J.;Ferre,N.;Fang,W.-H.Chem.Eur.J.2014,20,7979.
[2]Hou,C.;Liu,Y.-J.;Ferre,N.;Fang,W.-H.Chem.Eur.J.2014,20,7979.