Center for Advanced Materials Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China.
School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, China.
Molecules. 2021 Jul 12;26(14):4222. doi: 10.3390/molecules26144222.
Among all bioluminescent organisms, the firefly is the most famous, with a high luminescent efficiency of 41%, which is widely used in the fields of biotechnology, biomedicine and so on. The entire bioluminescence (BL) process involves a series of complicated in-vivo chemical reactions. The BL is initiated by the enzymatic oxidation of luciferin (LH). However, the mechanism of the efficient spin-forbidden oxygenation is far from being totally understood. Via MD simulation and QM/MM calculations, this article describes the complete process of oxygenation in real protein. The oxygenation of luciferin is initiated by a single electron transfer from the trivalent anionic LH () to O to form […O]; the entire reaction is carried out along the ground-state potential energy surface to produce the dioxetanone (FDO) via three transition states and two intermediates. The low energy barriers of the oxygenation reaction and biradical annihilation involved in the reaction explain this spin-forbidden reaction with high efficiency. This study is helpful for understanding the BL initiation of fireflies and the other oxygen-dependent bioluminescent organisms.
在所有生物发光生物中，萤火虫最为著名，其发光效率高达 41%，广泛应用于生物技术、生物医药等领域。整个生物发光（BL）过程涉及一系列复杂的体内化学反应。BL 由荧光素（LH）的酶促氧化引发。然而，高效的禁阻氧合的机制远未完全理解。通过 MD 模拟和 QM/MM 计算，本文描述了真实蛋白质中氧合的完整过程。荧光素的氧合是由三价阴离子 LH（）向 O 的单电子转移引发的，形成 […O]；整个反应沿着基态势能面进行，通过三个过渡态和两个中间体生成二氧戊环酮（FDO）。氧合反应和反应中涉及的双自由基消除的低能垒解释了这种高效率的禁阻自旋反应。本研究有助于理解萤火虫和其他依赖氧的生物发光生物的 BL 起始。
