Coelenterazine

History

Coelenterazine was simultaneously isolated and characterized by two groups studying the luminescent organisms sea pansy (Renilla reniformis) and the cnidarian Aequorea victoria, respectively. Both groups independently discovered that the same compound was used in both luminescent systems. The molecule was named after the now-obsolete phylum coelenterata. Likewise, the two main metabolites – coelenteramide and coelenteramine – were named after their respective functional groups. While coelenterazine was first discovered in Aequorea victoria, it was later shown that they do not synthesize coelenterazine, but obtain it through their diet, largely from crustaceans and copepods.

Occurrence

Coelenterazine is widely found in marine organisms including:

• radiolarians
• ctenophores
• cnidarians such as Aequorea victoria, Obelia geniculata and Renilla reniformis
• squid such as Watasenia scintillans and Vampyroteuthis infernalis
• shrimp such as Systellaspis debilis and Oplophorus gracilirostris
• copepods such as Pleuromamma xiphias, Gaussia princeps and Metridia lucens
• chaetognaths
• fish including some Neoscopelidae and Myctophidae
• echinoderms such as Amphiura filiformis

The compound has also been isolated from organisms that are not luminescent, such as the Atlantic herring and several shrimp species including Pandalus borealis and Pandalus platyuros.

The compound is generally used by luciferases internal to the organism, but in the copepod Metridia longa the luciferase is secreted into extracellular space, an unusual property.

Biosynthesis

Biosynthesis of coelenterazine in Metridia starts from two molecules of tyrosine and one molecule of phenylalanine, and some researchers believe this comes in the form of a cyclized "Phe-Tyr-Tyr" (FYY) peptide.

Properties

Coelenterazine can be crystallized into orange-yellow crystals. The molecule absorbs light in the ultraviolet and visible spectrum, with peak absorption at 435 nm in methanol, giving the molecule a yellow color. The molecule spontaneously oxidizes in aerobic conditions or in some organic solvents such as dimethylformamide and DMSO and is preferentially stored in methanol or with an inert gas.

Synthetic coelenterazine derivatives

To improve its biophysical properties, derivatives of coelenterazine have been synthesized by means of different procedures including multicomponent strategies.

References

References

1. Shimomura, O.. (2006). "Bioluminescence: Chemical Principles and Methods". [[World Scientific Publishing]].
2. (October 1977). "Structure of native Renilla reinformis luciferin". Proceedings of the National Academy of Sciences of the United States of America.
3. (April 1975). "Chemical nature of bioluminescence systems in coelenterates". Proceedings of the National Academy of Sciences of the United States of America.
4. (September 2001). "Can coelenterates make coelenterazine? Dietary requirement for luciferin in cnidarian bioluminescence". Proceedings of the National Academy of Sciences of the United States of America.
5. (14 September 2018). "Metridia lucens". PeerJ.
6. (1994). "A bioluminescent chaetognath". [[Nature (journal).
7. (January 2004). "Cloning and expression of cDNA for a luciferase from the marine copepod Metridia longa. A novel secreted bioluminescent reporter enzyme". The Journal of Biological Chemistry.
8. (30 June 2015). "Occurrence of Isopenicillin-N-Synthase Homologs in Bioluminescent Ctenophores and Implications for Coelenterazine Biosynthesis". PLOS ONE.
9. (2015). "Multicomponent Synthesis of Novel Coelenterazine Derivatives Substituted at the C-3 Position". [[Tetrahedron (journal).