The enzyme catalyzed oxidation of Cypridina luciferin

Source of oxygen in the CO(2) produced in the bioluminescent oxidation of firefly luciferin

Incorporation of (18)O into the CO(2) produced in the bioluminescent oxidation of firefly luciferin was studied. In H(2) (16)O medium with (18)O(2) gas, the product CO(2) contained up to 75% C(16)O(18)O, showing that one O of the product CO(2) arose from the O(2) that oxidized luciferin. This result is consistent with a dioxetane mechanism. Analysis of the mass spectral data of the CO(2) obtained in high-enrichment H(2) (18)O medium with (16)O(2) gas indicated the presence of about 20% contaminating CO(2), which contributes approximately 70% of the total incorporated (18)O. Thus the values of incorporated (18)O in H(2) (18)O medium with (16)O(2) gas have no significance in the present context. Data obtained with luciferases of the American firefly Photinus and Japanese firefly Luciola were similar.

Imaging of luciferase secretion from transformed Chinese hamster ovary cells

The blue luminescence characteristic of the marine ostracod crustacean Vargula hilgendorfii is from a simple, but highly specific, enzyme-substrate reaction. Light is emitted by the oxidation of Vargula luciferin (substrate) by molecular oxygen, a reaction catalyzed by luciferase. Stable transformants of Chinese hamster ovary cells carrying the Vargula luciferase gene secreted luciferase from discrete sites on the cell surface, and this secretion could be monitored in real time by the bioluminescence produced by the secreted luciferase in the presence of Vargula luciferin by using an image-intensifying technique. Addition of anti-Vargula luciferase IgG to the luminescing cells almost completely extinguished the luminescence, confirming that Vargula luciferase caused the luminescence.

Cloning and expression of cDNA for the luciferase from the marine ostracod Vargula hilgendorfii

The marine ostracod Vargula hilgendorfii ejects luciferin and luciferase into seawater to produce a bright luminous cloud. The light is due to the oxidation of luciferin, an imidazopyrazine compound, by molecular oxygen, catalyzed by luciferase. The mechanism of the reaction has been studied extensively and the 60 kcal/mol required for the blue emission have been shown to be derived from the oxidation of luciferin via a dioxetanone intermediate, in which the excited state oxyluciferin bound to luciferase is the emitter. However, only limited information is available regarding the properties of the enzyme. This paper reports the cloning and sequence analysis of the cDNA for Vargula luciferase and the expression of the cDNA in a mammalian cell system. The primary structure, deduced from the nucleotide sequence, consists of 555 amino acid residues in a single polypeptide chain with a molecular weight of 62,171. Two regions of the enzyme show significant amino acid sequence homology with an N-terminal segment of the photoprotein aequorin. The Vargula luciferase gene, which contains a signal sequence for secretion, should be well suited as a reporter in studies of gene expression.

Biological diversity, chemical mechanisms, and the evolutionary origins of bioluminescent systems

A diversity of organisms are endowed with the ability to emit light, and to display and control it in a variety of ways. Most of the luciferins (substrates) of the various phylogenetically distant systems fall into unrelated chemical classes, and, based on still limited data, the luciferases (enzymes) and reaction mechanisms are distinctly different. Based on its diversity and phylogenetic distribution, it is estimated that bioluminescence may have arisen independently as many as 30 times in the course of evolution. However, there are several examples of cross-phyletic similarities among the substrates; some of these may be accounted for nutritionally, but in other cases they may have evolved independently.

Spectral characteristics of the bioluminescence induced in the marine fish, Porichthys notatus by Cypridina (ostracod) luciferin

Specimens of Porichthys notatus, which are naturally luminous along the coast of California, are non-luminous in Puget Sound. However, luminescence capability may be induced in the adult Puget Sound Porichthys by the administration of purified Cypridina (ostracod) luciferin, synthetic Cypridina luciferin, or Cypridina organisms. The bioluminescence emission spectra produced by the Puget Sound fish following induction is similar, if not identical, to that of the naturally luminous Porichthys notatus from California waters (maxima: 485 and 507 nm).

Mechanism of oxidative carbon dioxide production during Renilla reniformis bioluminescence

The oxidation of luciferin catalyzed by sea pansy luciferase results in the emission of light. Molecular oxygen is required and carbon dioxide is produced. When the reaction occurs in the presence of H(2) (18)O, both of the oxygens of the carbon dioxide are labeled. One of the oxygens arises from the nonenzymic exchange of the ketone group of the substrate; the other oxygen is incorporated during the enzymic oxidation of the luciferin. When the reaction is carried out in the presence of (18)O(2), neither of the oxygens of the carbon dioxide is labeled. Thus the source of oxygen in the carbon dioxide is water. A mechanism for the oxidative reaction is proposed.

Cypridina Bioluminescence: Light-Emitting Oxyluciferin-Luciferase Complex

Fluorescence of Cypridina oxyluciferin is greatly enhanced when it is bound to luciferase; the spectrum is thereby shifted, so that it corresponds precisely to the emission spectrum characteristic of the bioluminescentoxidation of luciferin. Thus the oxyluciferin-luciferase complex is the lightemitter. The binding is equimolar, with dissociation constant K(D) equal to 3x 10(-7) mole per liter. The molecular weight of the luciferase, according to three different methods, is between 52,000 and 57,000; molecular activities of luciferase for the bioluminescence reaction and for the hydrolysis of oxy-luciferin are 1600 and 2 per minute, respectively.