In nature, the American firefly (photinus pyralis) uses the luciferase bioluminescence to find a partner for reproduction. The result of the luciferase reaction is the emission of yellow-green light at 560 nm. This reaction requires the enzyme luciferase, the substrate D-Luciferin and the co-factors ATP, Mg2+ and Oxygen. The reaction is a cascade of several steps: the initial adenylation of Luciferin is followed by oxidation to Oxyluciferin.
The Oxyluciferin resulting from this reaction is in an electronically excited state. On relaxation to ground state a photon is released (from 550 nm (yellow-green) at neutral pH to 620 nm (red) at low pH).
In modern biotechnology there are numerous applications for the Luciferase system.
- Food industry: As only living organisms produce ATP,
a positive Luciferase test on food surfaces is indicating microbial contamination [1]. - Identification of gene expression[2] at very low level: As luciferase is naturally absent in
almost any cells, this system is a very sensitive method for detection in the luc reporter gene system. - Modern applications are the identification of protein-protein interactions,
measuring the activity of cellular receptors or monitoring of tumor growth[3].
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