luciferin

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

Luciferins (from the Latin lucifer, "light-bringer") are a class of light-emitting biological pigments found in organisms that causes bioluminescence. The term is used generically to refer to any light emitting molecule utilized by a luciferase or photoprotein.^[1]

Types

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 each for their corresponding protein enzyme luciferase. Luciferins are oxidized in the presence of the enzyme luciferase to produce oxyluciferin and energy in the form of light. As it is not known just how many types of luciferins there are, some of the better studied compounds are listed below. There are many types of luciferins though they all share the use of reactive oxygen species to emit light.^[2]

Firefly

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 was unusual as it was found that ATP was required for light emission.^[3]

Snail

Latia luciferin is chemically (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

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

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

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

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

References

External links

• "Major luciferin types". The Bioluminescence Web Page. University of California, Santa Barbara. 2009-01-09. http://www.lifesci.ucsb.edu/~biolum/chem/detail1.html. Retrieved 2009-03-06.