Luciferin

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This is a space-filling model of firefly luciferin. Color coding: yellow=sulfur; blue=nitrogen; black=carbon; red=oxygen; white=hydrogen.

Luciferin (from the Latin lucifer, "light-bringer") is a generic term for the light-emitting compound found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalysed oxidation and the resulting excited state intermediate emits light upon decaying to its ground state. This may refer to molecules that are substrates for both luciferases and photoproteins.[1]

Types[edit]

This structure of firefly luciferin is reversed (left to right) from the space-filling model shown above

Luciferins are a class of small-molecule substrates that are oxidized in the presence of the enzyme luciferase to produce oxyluciferin and energy in the form of light. It is not known just how many types of luciferins there are, but some of the better-studied compounds are listed below. There are many types of luciferins, yet all share the use of reactive oxygen species to emit light.[2]

Firefly[edit]

Main article: Firefly luciferin

Firefly luciferin is the luciferin found in many Lampyridae species. It is the substrate of luciferase (EC 1.13.12.7) responsible for the characteristic yellow light emission from fireflies. The chemistry is unusual, as it was found that ATP is required for light emission.[3]

Snail[edit]

This structure of Latia luciferin

Latia luciferin is, in terms of chemistry, (E)-2-methyl-4-(2,6,6-trimethyl-1-cyclohex-1-yl)-1-buten-1-ol formate and is from freshwater snail Latia neritoides.[4]

Bacterial[edit]

Bacterial luciferin is a type of luciferin found in bacteria, some of which live within the specialized tissues of some squid and fish. It consists of a long-chain aldehyde and a reduced riboflavin phosphate.

Coelenterazine[edit]

Main article: Coelenterazine
Coelenterazine

Coelenterazine is found in radiolarians, ctenophores, cnidarians, squid, copepods, chaetognaths, fish, and shrimp. It is the prosthetic group in the protein aequorin responsible for the blue light emission.[5]

Dinoflagellate[edit]

Dinoflagellate luciferin is a chlorophyll derivative and is found in dinoflagellates, which are often responsible for the phenomenon of nighttime ocean phosphorescence. A very similar type of luciferin is found in some types of euphausiid shrimp.

Vargulin[edit]

Main article: Vargulin

Vargulin is found in certain ostracods and deep-sea fish, to be specific, Poricthys. Like the compound coelenterazine, it is an imidazopyrazinone and emits primarily blue light in the animals.

References[edit]

  1. ^ Hastings JW (1996). "Chemistries and colors of bioluminescent reactions: a review". Gene 173 (1 Spec No): 5–11. doi:10.1016/0378-1119(95)00676-1. PMID 8707056. 
  2. ^ Hastings JW (1983). "Biological diversity, chemical mechanisms, and the evolutionary origins of bioluminescent systems". J. Mol. Evol. 19 (5): 309–21. doi:10.1007/BF02101634. PMID 6358519. 
  3. ^ Green A, McElroy WD (October 1956). "Function of adenosine triphosphate in the activation of luciferin". Arch. Biochem. Biophys. 64 (2): 257–71. doi:10.1016/0003-9861(56)90268-5. PMID 13363432. 
  4. ^ EC 1.14.99.21. ORENZA: a database of ORphan ENZyme Activities, accessed 27 November 2009.
  5. ^ Shimomura O, Johnson FH (April 1975). "Chemical nature of bioluminescence systems in coelenterates". Proc. Natl. Acad. Sci. U.S.A. 72 (4): 1546–9. doi:10.1073/pnas.72.4.1546. PMC 432574. PMID 236561. 

External links[edit]

  • "Major luciferin types". The Bioluminescence Web Page. University of California, Santa Barbara. 2009-01-09. Retrieved 2009-03-06.