Investigation of the Dinoflagellate Bioluminescence Mechanism: Chemically Initiated Electron Exchange Luminescence or Twisted Intramolecular Charge Transfer?
| Autor: | Steven O. Mansoorabadi, Phong D. Ngo |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010304 chemical physics
biology Chemistry Organic Chemistry Dinoflagellate 010402 general chemistry biology.organism_classification Photochemistry 01 natural sciences Luciferin 0104 chemical sciences Analytical Chemistry Excited state Intramolecular force 0103 physical sciences Bioluminescence Molecular orbital Density functional theory Physical and Theoretical Chemistry Luminescence |
| Zdroj: | ChemPhotoChem. 1:383-387 |
| ISSN: | 2367-0932 |
| DOI: | 10.1002/cptc.201700060 |
| Popis: | Ubiquitous in the world's oceans, dinoflagellates are capable of fantastic displays of bright blue bioluminescence. This luminosity is a consequence of the oxidation of an open-chain tetrapyrrole, dinoflagellate luciferin (LH2), by the enzyme dinoflagellate luciferase (LCF). While many other bioluminescence systems are well understood, the reaction mechanism of LCF remains enigmatic. A comprehensive density functional theory investigation was used to evaluate several competing mechanisms of LCF catalysis employing distinct excited state luminophores. The results provide strong evidence in favor of a mechanism of dinoflagellate bioluminescence involving an excited state gem-diol(ate) intermediate. Analysis of the molecular orbitals relevant to the emission process indicates that catalysis from the E-isomer of LH2 is likely to proceed via a chemically initiated electron exchange luminescence reaction, while that from the Z-isomer may involve the formation of a biologically unprecedented twisted intramolecular charge transfer state. |
| Databáze: | OpenAIRE |
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