甲藻生物发光机理的量子化学研究

Bioluminescence is a widespread phenomenon in nature, especially in the marine environment. People often observe bright light in the surface ocean. Dinoflagellate, a kind of eukaryotic protists is mainly responsible for this blue light. The dinoflagellate bioluminescence has been used to assess the pollution of heavy metals in water, and probably can be employed as a new technique in military and marine monitoring to detect the targets under water. Considering its prominence and ecological importance, dinoflagellate bioluminescence has received little attention by experimentalists. Moreover, there has not been any level of quantum chemical study. Both the bioluminescent process and mechanism are not clear. Fortunately, the molecular structure of the luciferin and the x-ray structure of a kind of lucifrase of bioluminescent dinoflagellate have been roughly confirmed, which is the base of theoretical study. This project will employ the quantum mechanics, combination of quantum mechanics and molecular mechanics and molecular dynamics to study every chemical reaction and its mechanism, the spectra and energetics of the bioluminescence process in the protein environment. The purpose is to expand and support the application of dinoflagellate bioluminescence by understanding its details, mechanism, chemical origin and effects on light emission at the molecular and electronic-state levels.

生物发光现象在自然界特别是在海洋中广泛存在。海洋表层经常在夜晚发出明亮的蓝光。这种蓝光主要由一类真核原生生物发光甲藻产生。甲藻发光已经被用来评价水体重金属污染，也有望作为水下目标探测新手段用于军事和海洋环境监测。相对于其在海洋发光中的普遍性和对海洋生态环境的重要性，对甲藻发光的实验研究很少。目前也没有任何形式的理论研究。甲藻发光的整个发光过程和机理尚不清楚。有限的实验研究大致确定了发光甲藻的荧光素分子和一种荧光素酶的结构。这为理论研究提供了基础。本项目将从发光甲藻的荧光素分子入手，在蛋白环境内，使用量子力学、组合量子力学分子力学以及分子动力学的计算手段来研究其发光过程所经历的每一步化学反应以及相应的谱学和能量学等问题，以期在分子和电子态水平阐明甲藻发光的细节、机理、化学起源和影响发光的因素，为拓展其实际应用提供理论依据和指导。

生物发光现象在自然界特别是在海洋中广泛存在。海洋表层经常在夜晚发出明亮的蓝光。这种蓝光主要由一类真核原生生物发光甲藻产生。甲藻发光已经被用来评价水体重金属污染，也有望用于军事和海洋环境监测。相对于其在海洋发光中的普遍性和对海洋生态环境的重要性，对甲藻发光的实验研究很少。在该项目之前没有任何形式的理论研究。该项目综合采用密度泛函理论、含时密度泛函理论、完全活化空间自洽场方法和完全活化空间二阶微扰等量子力学方法，首次研究了甲藻发光生物中的荧光素所经历的一系列反应，详细阐述了直链型和四元环型两类高能中间体的加氧形成机理，并提出在作为电子供体的第二个荧光素分子的参与下，直链型高能中间体发生过氧键解离可通过化学诱导电子交换发光机理生成激发态的荧光素分子作为发光体发光。项目在分子和电子态水平阐明了甲藻发光的细节、机理、化学起源，为拓展其实际应用提供理论依据和指导。