title: The dynamics simulation and quantum calculation investigation about luminescence mechanism of coelenteramide.
abstract: The dynamics simulation and quantum chemical calculation are employed to investigate spectrum properties of deprotonation process of coelenteramide and two final states neutral state and phenolate anion. According to the calculation results, theoretical evidence supporting the luminescence mechanism hypothesis is proposed in a significant bioluminescence process. In vivo of marine bioluminescent organisms, if the protein motion provides the conditions for the deprotonation of coelenteramide in some protein molecules, the phenolate anion is completely deprotonated coelenteramide as an emitter in these protein molecules and emits fluorescence assigned to the lower energy peak. And in another emitter in which the condition of deprotonation is not met, the fluorescence is produced by the neutral state of coelenteramide and assigned to the higher energy peak. The energy difference decreases gradually when the proton of coelenteramide gradually approaches to His22. For phenolate anion and neutral state, electronic cloud distributions between their each frontier molecular orbitals HOMO and LUMO have high overlapping volume. The molecular electrostatic potential indicates that for phenolate anion, the oxygen atom after deprotonation has greater electron density, which is good for formation hydrogen bonds with amino acids in the environment.
authors.affiliation: State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, China.
authors.forename: Zuo-Sheng
authors.initials: ZS
authors.lastname: Li
authors.forename: Xi
authors.initials: X
authors.lastname: Zhao
authors.forename: Lu-Yi
authors.initials: LY
authors.lastname: Zou
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Ren
mesh_terms: D044482:Benzeneacetamides / Q000737:chemistry*; D003198:Computer Simulation; D049449:Luminescence; D008956:Models, Chemical; D008958:Models, Molecular; D056951:Photoelectron Spectroscopy; D011487:Protein Conformation; D011719:Pyrazines / Q000737:chemistry*; D013054:Spectrophotometry, Atomic; D013237:Stereoisomerism
chemical_list: D044482:Benzeneacetamides; D011719:Pyrazines; C542661:coelenteramide