User:ShrimpEyes813/Cypridina-luciferin 2-monooxygenase

Cypridina-luciferin 2-monooxygenase, CLase, (EC 1.13.12.6), is a protein that serves as a bioluminescent enzyme found in a certain bioluminescent crustacean known as Cypridina. As per its EC number, it belongs to a family of oxidoreductases, which catalyze the transfer of electrons form one molecule, the reductant, to another, the oxidant. It belongs specifically to those acting on single donors with the incorporation of molecular oxygen, oxygenases. The oxygen incorporated does not need to be derived from O with incorporation of one atom of oxygen (internal monooxygenases or internal mixed-function oxidases). The systematic name of this enzyme class is Cypridina-luciferin:oxygen 2-oxidoreductase (decarboxylating). Other names in common use include Cypridina-type luciferase, luciferase (Cypridina luciferin), and Cypridina luciferase. The enzyme may be assayed by measurement of light emission from the chemical reaction.

Chemical Reaction
CLuc is an oxidoreductase, specifically acting on single donors with O2 as the oxidant. Thus, the bioluminescent reaction that Cypridina luciferase catalyzes is simple, requiring only the substrate luciferin, the enzyme luciferase and oxygen necessary to produce light. CLuc catalyzes the chemical reaction:

Cypridina luciferin + O2 ⇌  oxidized Cypridina luciferin + CO2 + hnu

Thus, the two substrates of Cypridina luciferase are Cypridina luciferin and O2, whereas its 3 products are oxidized Cypridina luciferin, CO2, and light. As per enzyme kinetics, the addition of CLase increases the rate of the process of bioluminescence.

Biological Functions and Organisms Found In
As discussed, this enzyme is an oxidoreductase, oxygenase, and furthermore an internal monooxygenase/interal mixed-function oxygenase as per its EC number. Oxygen is needed for bioluminescence to oxxur, to CLase introduces 1 molecule of oxygen into the reaction when it binds to Cypridina-luciferin.

Cypridina luciferase is found in bioluminescent crustaceans of the family Cypridinidae of the ostracods. When disturbed, these ostracods emit a light cloud of luciferin and luciferase into the water column, likely as a defense mechanism to ward off predators. The light results when the luciferin is oxidized by molecular oxygen. The bioluminescence of this enzyme is best studied in Vargula hilgendorfii, formerly Cypridina hilgendorfii, which is better known as the “sea-firefly." While it is known that Cypridina luciferase is found in these bioluminescent crustacea, the luciferases, potentially as well as luciferins as they cross react, of certain bioluminescent fish seem to be similar. It is currently being studied to determine if these organisms bear the same enzymes as Cypridina ostracods . According to BRENDA, this enzyme also appears in viruses . While CLase is an important part of all of these organisms and the reaction it catalyzes, it is only detected in the photophores, wherease luciferin is found in both the photophores and tissues of the body

Structure
The primary sequence of this enzyme was determined by cloning the cDNA. As of 2020, the crystalline structure of Cypridina luciferase is unknown, as is information about its active sites and various catalytic mechanisms. However, the crystalline structure of its substrate, Cypridina luciferin, is known, and is something that scientists are currently using to determine the structure of Cypridina luciferase. The crystalline structure of Cypridina luciferin may also allow for the eventual discovery of the active site(s) of CLase.

As an example of the genomic structure of Cypridina luciferase, the genomic structure of this enzyme in the sample organism Vargula hilgendorfii consists of a complex genetic organization. It is comprised of 13 exons and 12 introns, with some clones, such as λ34 and λ61. Clone λ45, however, contains only the first five exons. Notably, the splicing sites within λ34 and λ61 conform precisely to a consensus sequence. When these genes are translated, they yield luciferase proteins, each consisting of 555 amino acid residues in a singular polypeptide chain with a molecular weight of 62,171. These luciferase proteins share a high degree of identity, with over 98.6% similarity to those found in previously reported cDNA clones. However, the introns in these clones exhibit significant variation in length, suggesting the presence of structural diversity within the luciferase gene.

Mechanism
Investigations into this enzyme show that, when luciferin exposed to Cypridina luciferase and oxygem, it is converted to two compounds, deened oxyluciferin and etioluciferin that results in bioluminescence. This synthesis and change is confirmed in Karpetsky et al.

The CLase mediated chemical reaction involves the catalytic oxidation of Cypridina luciferin. The change in crystalline structure that takes place during this is found on the BRENDA Enzyme Database.

New Developments in the Field
Bioluminescence reporter imaging is a tool that is often used in cancer biology for monitoring tumor development and study other biological processes. In a recent study by Moroz et al., researchers introduced a new bioluminescent reporter called membrane-anchored Cypridina luciferase (maCLuc), which doesn’t interfere with other established luciferase reporters when paired with its substrate. This reporter gene was derived from Cyrpdina luciferase.