Coelenterazine is a

luciferin Luciferin (from the Latin ''lucifer'', "light-bearer") is a generic term for the light-emitting compound found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalyzed reaction with molecular oxygen. The result ...

, a molecule that emits light after reaction with

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

, found in many aquatic organisms across eight phyla. It is the substrate of many

luciferase Luciferase is a generic term for the class of oxidative enzymes that produce bioluminescence, and is usually distinguished from a photoprotein. The name was first used by Raphaël Dubois who invented the words ''luciferin'' and ''luciferase'', ...

s such as ''

Renilla reniformis The sea pansy, ''Renilla reniformis,'' is a species of colonial cnidarian in the family Renillidae, part of an octocoral subclass of Anthozoa that inhabit an expansive range of environments. It is native to warm continental shelf waters of th ...

(Rluc), ''Gaussia'' luciferase (Gluc), and

photoprotein Photoproteins are a type of enzyme, made of protein, from bioluminescent organisms. They add to the function of the luciferins whose usual light-producing reaction is catalyzed by the enzyme luciferase. History The term photoprotein was first use ...

s, including

aequorin Aequorin is a calcium-activated photoprotein isolated from the hydrozoan ''Aequorea victoria''. Its bioluminescence was studied decades before the protein was isolated from the animal by Osamu Shimomura in 1962. In the animal, the protein occur ...

, and obelin. All these proteins catalyze the oxidation of this substance, a reaction catalogued EC 1.13.12.5.

History

Coelenterazine was simultaneously isolated and characterized by two groups studying the luminescent organisms sea pansy (''Renilla reniformis'') and the cnidarian ''

Aequorea victoria ''Aequorea victoria'', also sometimes called the crystal jelly, is a bioluminescent hydrozoan jellyfish, or hydromedusa, that is found off the west coast of North America. The species is best known as the source of two proteins involved in biolu ...

'', 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 Coelenterata is a term encompassing the animal phyla Cnidaria (coral animals, true jellies, sea anemones, sea pens, and their relatives) and Ctenophora (comb jellies). The name comes , referring to the hollow body cavity common to these two phyl ...

. Likewise, the two main metabolites – coelenteramide and coelenteramine – were named after their respective

functional groups In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest ...

. While coelenterazine was first discovered in ''

'', 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: *

radiolarian The Radiolaria, also called Radiozoa, are protozoa of diameter 0.1–0.2 mm that produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm. The elab ...

s * ctenophores * cnidarians such as ''

'', ''

Obelia geniculata ''Obelia geniculata'' is a species of cnidarian belonging to the family Campanulariidae. The species has cosmopolitan distribution. Population genetics Estimates of divergence times and distinctive haplotypes provide evidence of glacial re ...

'' and ''

'' *

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

such as '' Watasenia scintillans'' and ''

Vampyroteuthis infernalis The vampire squid (''Vampyroteuthis infernalis'', lit. 'vampire squid from hell') is a small cephalopod found throughout temperate and tropical oceans in extreme deep sea conditions. The vampire squid uses its bioluminescent organs and its uni ...

'' *

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

such as '' Systellaspis debilis'' and '' Oplophorus gracilirostris'' *

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

s such as '' Pleuromamma xiphias'' and '' Gaussia princeps'' *

chaetognath The Chaetognatha or chaetognaths (meaning ''bristle-jaws'') are a phylum of predatory marine worms that are a major component of plankton worldwide. Commonly known as arrow worms, about 20% of the known Chaetognatha species are benthic zone, be ...

s *

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

including some Neoscopelidae and Myctophidae *

echinoderm An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea ...

s such as '' Amphiura filiformis'' The compound has also been isolated from organisms that are not luminescent, such as the

Atlantic herring Atlantic herring (''Clupea harengus'') is a herring in the family (biology), family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large ...

and several

species including ''

Pandalus borealis ''Pandalus borealis'' is a species of caridean shrimp found in cold parts of the northern Atlantic and northern Pacific Oceans, although the latter population now often is regarded as a separate species, ''P. eous''. The Food and Agriculture Orga ...

'' and '' Pandalus platyuros''.

Biosynthesis

Biosynthesis of coelenterazine in ''Metridia'' starts from two molecules of

tyrosine -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Gr ...

and one molecule of

phenylalanine Phenylalanine (symbol Phe or F) is an essential α-amino acid with the formula . It can be viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine. This essential amino a ...

, and some researchers believe this comes in the form of a cyclized "Phe-Tyr-Tyr" (FYY) peptide. Many members of the genus ''Metridia'' also produce luciferases that use this compound, some of which are secreted into extracellular space, an unusual property for luciferases.

Properties

Coelenterazine can be crystallized into orange-yellow crystals. The molecule absorbs light in the

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...

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 Dimethylformamide is an organic compound with the formula ( CH3)2NC(O)H. Commonly abbreviated as DMF (although this initialism is sometimes used for dimethylfuran, or dimethyl fumarate), this colourless liquid is miscible with water and the majo ...

and

DMSO Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula ( CH3)2. This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds an ...

and is preferentially stored in

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...

or with an

inert gas An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to ...

Synthetic coelenterazine derivatives

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

References

External links

Bioluminescence Page
showing major luciferin types.

External links

*{{Commonscatinline Bioluminescence Aminopyrazines Imidazopyrazines Lactams Phenols Luciferins

History

Occurrence

Biosynthesis

Properties

Synthetic coelenterazine derivatives

See also

References

External links

External links