Vargulin
Chemical compound
From Wikipedia, the free encyclopedia
Vargulin,[1] also called Cypridinid luciferin,[2] Cypridina luciferin, or Vargula luciferin, is the luciferin found in the ostracod Cypridina hilgendorfii, also named Vargula hilgendorfii.[3] These bottom dwelling ostracods emit a light stream into water when disturbed presumably to deter predation. Vargulin is also used by the midshipman fish, Porichthys.
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| Names | |
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| IUPAC name
2-[3-[2-[(2S)-butan-2-yl]-6-(1H-indol-3-yl)-3-oxo-7H-imidazo[2,
1-c]pyrazin-8-yl]propyl]guanidine | |
Other names
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| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C22H27N7O | |
| Molar mass | 405.506 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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History
A partial extraction procedure was developed in 1935 which involved reacting the compound with benzoyl chloride to allow it to be separated from the water-soluble components.[4] The compound was first isolated and purified to crystals by Osamu Shimomura.[5] The structure of the compound was confirmed some years later.[6] Feeding experiments suggest that the compound is synthesized in the animal from three amino-acids: tryptophan, isoleucine, and arginine.[7]
Biochemistry
Vargulin is oxidized by cypridina-luciferin 2-monooxygenase,[8][9][10] a 62 kDa enzyme, to produce blue light at 462 nm (max emission, detected with a 425 to 525 nm filter).
The vargulin does not cross react with luciferases using coelenterazine or Firefly luciferin.
Uses
Vargulin (with the associated luciferase) has applications in biotechnology:
- in a variety of assays, to report gene or gene expression after luciferase have been genetically introduced in cells,
- to detect ATP, that is used in the vargulin/luciferase reaction (cell viability assays).[11]
Although less stable, the Cypridina system is useful because can be used in multiplex assays with other (red-emitting) luciferin assays.
