Gaussia luciferase: A highly unusual enzyme

The luciferase from the mesopelagic planktonic crustacean Gaussia princeps has garnered attention as reporter protein due to its small size and its ability to produce a very bright luminescence. Over the past two decades much research has focused on the development of improved mutant variants as well as variants designed by combining sequence information from luciferases from several related copepod species. Gaussia luciferase is however of basic scientific interest because it is unusual in two main respects. First, structural analysis of Gaussia luciferase has demonstrated that this enzyme is extensively disordered with little hydrophobic core. This has complicated the identification of a substrate binding site and elucidation of the enzymatic mechanism remains obscure. Second, this luciferase is subject to rapid irreversible inactivation upon oxidation of its substrate, coelenterazine. These findings open fundamental enzymology questions and have significant implications for the use of Gaussia luciferase in life sciences; areas such as bioluminescence-based reporting assays and in high-throughput screening. Thus, past research is examined considering these recent findings, and with special emphasis on their implications for consistent assays and evaluation of mutant variants.