Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
J Chem Theory Comput. 2020 Jun 9;16(6):3904-3909. doi: 10.1021/acs.jctc.0c00074. Epub 2020 May 15.
Bioluminescent beetles, firefly, click beetle, and railroad worm, naturally emit different-color light via the identical luciferin and bioluminescence (BL) mechanisms. Railroad worm especially emits two colors of light in its dorsal-lateral and cephalic lanterns. Four computational models of bioluminophore (oLu) in luciferases of red-emitting, yellow-green-emitting, red-emitting with additional loop, and red-emitting without C-terminal were built in this paper. To unveil the details of this luciferase effect at the molecular and electronic-state levels, second-order multiconfigurational perturbation calculations were performed following molecular dynamic simulations and time-dependent density functional calculations for the above four oLu-luciferase systems. Via a systematic analysis on properties of oLu at the first singlet state (S-oLu) in different luciferases, one clearly see the details of the microenvironment and secondary structure of luciferase affecting the excited-state property of S-oLu, which ultimately result in the variant color of light emission. Typically, the increase in charge transfer of S-oLu leads to the longer wavelength BL.
生物发光甲虫、萤火虫、叩头虫和铁路蠕虫通过相同的荧光素和生物发光 (BL) 机制自然发出不同颜色的光。铁路蠕虫特别在其背外侧和头灯笼中发出两种颜色的光。本文构建了四种生物发光体（oLu）在红色发射、黄绿发射、带附加环的红色发射和不带 C 末端的红色发射荧光酶中的计算模型。为了揭示这种荧光酶效应在分子和电子态水平上的细节，在分子动力学模拟和上述四个 oLu-荧光酶体系的时间相关密度泛函计算之后，进行了二阶多组态微扰计算。通过对不同荧光酶中第一单重态 (S-oLu) 的 oLu 性质的系统分析，可以清楚地看到荧光酶的微环境和二级结构对 S-oLu 激发态性质的影响，这最终导致了发光颜色的变化。通常，S-oLu 的电荷转移增加会导致 BL 波长变长。
