Guo Ya-Jie, Cui Cheng-Xing, Liu Ya-Jun
Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China.
School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang, China.
Photochem Photobiol. 2022 Jan;98(1):184-192. doi: 10.1111/php.13496. Epub 2021 Aug 7.
Among numerous bioluminescent organisms, firefly is the most studied one. Recent experiment proposed that sulfoluciferin (SLH ) may serve as a storage form of luciferin (LH ). In the present article, we employed density functional theory calculation to uncover the mechanism and detailed process of the storage and release reactions. Due to lack of available crystallographic structure of the related enzyme, the calculation was performed on a model system. For the storage reaction, possible amino acid residues were used for imitating the protein environment. For the release reaction, the dielectric constant of 3.0 was employed to simulate the polarity of the protein cavity. The computational results indicated that the reactions from LH to SLH and from SLH to LH are both exergonic, which favor the storage and release processes and coincide with the experimental observation. Basing on experimental and current theoretical study, we supplemented the stages of LH storage and release in the entire bioluminescent cycle of firefly. The current theoretical calculation could inspire the study on LH storage and release of other bioluminescent organisms.
在众多生物发光生物中，萤火虫是研究最多的一种。最近的实验表明，磺酸荧光素（SLH）可能是荧光素（LH）的一种储存形式。在本文中，我们采用密度泛函理论计算来揭示储存和释放反应的机制及详细过程。由于缺乏相关酶的可用晶体结构，计算是在一个模型系统上进行的。对于储存反应，使用可能的氨基酸残基来模拟蛋白质环境。对于释放反应，采用介电常数3.0来模拟蛋白质腔的极性。计算结果表明，从LH到SLH以及从SLH到LH的反应都是放能的，这有利于储存和释放过程，与实验观察结果一致。基于实验和当前的理论研究，我们补充了萤火虫整个生物发光循环中LH储存和释放的阶段。当前的理论计算可能会激发对其他生物发光生物LH储存和释放的研究。
