Oplophorus-luciferin 2-monooxygenase

Last updated
Oplophorus-luciferin 2-monooxygenase
Identifiers
EC no. 1.13.12.13
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
Search
PMC articles
PubMed articles
NCBI proteins

In enzymology, an Oplophorus-luciferin 2-monooxygenase (EC 1.13.12.13), also known as Oplophorus luciferase (referred in this article as OpLuc) is a luciferase, an enzyme, from the deep-sea shrimp Oplophorus gracilirostris [2], belonging to a group of coelenterazine luciferases. Unlike other luciferases, it has a broader substrate specificity [3,4,6] and can also bind to bisdeoxycoelenterazine efficiently [3,4]. It is the third example of a luciferase (Other than Aequorea and Renilla) to be purified in lab [2]. The systematic name of this enzyme class is Oplophorus-luciferin:oxygen 2-oxidoreductase (decarboxylating). This enzyme is also called Oplophorus luciferase.

Contents

Chemical reaction

The two substrates of this enzyme are the luciferin, Coelenterazine and O2 and its 3 products are the oxyluciferin, Coelenteramide, CO2, and light. This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O2 as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O with incorporation of one atom of oxygen (internal monooxygenases o internal mixed-function oxidases). Although the enzyme is part of the group of enzymes that act on coelenterazine, such as Renilla and Gaussia luciferases, it does not share base pair sequences with these enzymes [3,4,5,7].

OpLuc catalyzes the ATP independent chemical reaction [3,4,5,6]:

coelenterazine (Oplophorus luciferin) + O2 coelenteramide + CO2 + hν

The result of this process in some loss in CO2 as well as a photon of blue light emitted at   ~460 nm [2,3,4]. This reaction has an optimal pH of 9, optimal salt concentration of 0.05-0.1 M, and optimal temperature of ~40 C (making it an unusually heat resistant luciferase) [2], although because O.gracilirostris are deep sea animals living in below 20 C temperatures, luciferase is normally expressed and folded at low temperatures [6].

Biological Function

When stimulated in Oplophorus gracilirostris, OpLuc is secreted from the base of legs and antennae of the deep-sea shrimp as a defense mechanism. This mechanism causes O.gracilirostris release a luminous, bright blue luciferase cloud [2].

Oplophorus gracilirostris Oplophorus gracilirostris (MNHN-IU-2013-2565).jpeg
Oplophorus gracilirostris

Enzyme Pathway

The small protein subunit of OpLuc, 19kda, has an amino terminal peptide sequence that, when stimulated, signals the enzyme to bind to the coelenterazine, Oplophorus luciferin (the substrate) [3,7]. Shown in figure 1,the enzyme then oxidizes the coelenterazine in a water medium into the luminescent product, coelenteramide, and releases CO2 as a byproduct [2,3,7].

Structure

OpLuc is a complex of two covalently bonded [3] protein subunits: two molecules of 19 kDa and two molecules of 35 kDa components, making it a heterotetrameric molecule. The proteins signal the enzyme for secretion in luminescence, catalyzed by the protein 19 kDa [3,4,7]. The luciferase has many cysteine residues that stabilize the enzyme in extracellular environments using disulfide bonds [5].

19 kDa Protein

This catalytic component of OpLuc has 196 amino acids [3] with one cysteine in the carboxyl terminus and is distinct from proteins found in other luciferases [4]. The protein is made up of two domains with repetitive sequencing of Ia-c and Ila-d in the peptide chain [4]. It is thought to be the protein to cause the bioluminescent reaction of O.gracilirostris, but functions ineffectively without its larger, subunit counterpart [3,4]. Although the crystal structure of OpLec has yet to be completely analyzed and mapped, 19 kDa experimentally expressed in mammalian cells (regarded as KAZ [7]). The protein was isolated and mutated to catalyze a bright and sustained luminescent reaction to create an engineered luciferase, NanoLuc (NLuc), and a coelenterazine analogue (furimazine) to be used as a cellular reporter [5,8]. A mutated ribbon model of the 19 kDa protein (named nanoKaz) is shown in figure 2.

35 kDa Protein

The lesser known component of the OpLuc enzyme has 320 amino acids [3] with 11 cysteine and 5 leucine molecules [4]. The amino terminus of the protein was experimentally concluded to begin at 39 amino acids [3].  It is thought to stabilize 19 kDa and is not thought to be affect by substrate specificity [3], however its exact function is not known [3,4,7].

Mechanism

Although originally thought to have the exact same mechanism as the Renilla luciferase [1], this luminescence has two possible reaction routes [2], as shown in figure 3. In the top route, Oplophorus luciferin (the coelenterazine displayed as I in the scheme) is oxidized when it combines with O2(radioactively labelled O18 was used in lab experiment) in a water medium and uses a dioxetane peroxide intermediate resulting in a CO2 product and coelenteramide (II in the scheme). The lower pathway does not use an intermediate and has rapid exchanges of oxygen with the water medium. Studies show there is less product yield and is suggested to have partial involvement in the overall reaction [2]. It should be noted, however, it is likely CO2 contamination during experiments demonstrated higher yield than was occurring for the lower pathway, making this pathway highly unlikely in natural conditions [2].

Related Research Articles

<span class="mw-page-title-main">Bioluminescence</span> Emission of light by a living organism

Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria, and terrestrial arthropods such as fireflies. In some animals, the light is bacteriogenic, produced by symbiotic bacteria such as those from the genus Vibrio; in others, it is autogenic, produced by the animals themselves.

<span class="mw-page-title-main">Luciferase</span> Enzyme family

Luciferase is a generic term for the class of oxidative enzymes that produce bioluminescence, and is usually distinguished from a photoprotein. The name was first used by Raphaël Dubois who invented the words luciferin and luciferase, for the substrate and enzyme, respectively. Both words are derived from the Latin word lucifer, meaning "lightbearer", which in turn is derived from the Latin words for "light" (lux) and "to bring or carry" (ferre).

<span class="mw-page-title-main">RuBisCO</span> Key enzyme of the photosynthesis involved in carbon fixation

Ribulose-1,5-bisphosphate carboxylase/oxygenase, commonly known by the abbreviations RuBisCo, rubisco, RuBPCase, or RuBPco, is an enzyme involved in light-independent part of photosynthesis, including the carbon fixation by which atmospheric carbon dioxide is converted by plants and other photosynthetic organisms to energy-rich molecules such as glucose. It emerged approximately four billion years ago in primordial metabolism prior to the presence of oxygen on earth. It is probably the most abundant enzyme on Earth. In chemical terms, it catalyzes the carboxylation of ribulose-1,5-bisphosphate.

<span class="mw-page-title-main">Luciferin</span> Class of light-emitting chemical compounds

Luciferin is a generic term for the light-emitting compound found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalyzed reaction with molecular oxygen. The resulting transformation, which usually involves splitting off a molecular fragment, produces an excited state intermediate that emits light upon decaying to its ground state. The term may refer to molecules that are substrates for both luciferases and photoproteins.

<span class="mw-page-title-main">Förster resonance energy transfer</span> Photochemical energy transfer mechanism

Förster resonance energy transfer (FRET), fluorescence resonance energy transfer, resonance energy transfer (RET) or electronic energy transfer (EET) is a mechanism describing energy transfer between two light-sensitive molecules (chromophores). A donor chromophore, initially in its electronic excited state, may transfer energy to an acceptor chromophore through nonradiative dipole–dipole coupling. The efficiency of this energy transfer is inversely proportional to the sixth power of the distance between donor and acceptor, making FRET extremely sensitive to small changes in distance.

<i>Noctiluca scintillans</i> Bioluminescent, marine dinoflagellate

Noctiluca scintillans is a marine species of dinoflagellate that can exist in a green or red form, depending on the pigmentation in its vacuoles. It can be found worldwide, but its geographical distribution varies depending on whether it is green or red. This unicellular microorganism is known for its ability to bioluminesce, giving the water a bright blue glow seen at night. However, blooms of this species can be responsible for environmental hazards, such as toxic red tides. They may also be an indicator of anthropogenic eutrophication.

<span class="mw-page-title-main">Aequorin</span> Calcium-activated photoprotein

Aequorin is a calcium-activated photoprotein isolated from the hydrozoan Aequorea victoria. Its bioluminescence was studied decades before the protein was isolated from the animal by Osamu Shimomura in 1962. In the animal, the protein occurs together with the green fluorescent protein to produce green light by resonant energy transfer, while aequorin by itself generates blue light.

<span class="mw-page-title-main">Firefly luciferase</span>

Firefly luciferase is the light-emitting enzyme responsible for the bioluminescence of fireflies and click beetles. The enzyme catalyses the oxidation of firefly luciferin, requiring oxygen and ATP. Because of the requirement of ATP, firefly luciferases have been used extensively in biotechnology.

<span class="mw-page-title-main">Firefly luciferin</span> Chemical compound

Firefly luciferin is the luciferin, or light-emitting compound, used for the firefly (Lampyridae), railroad worm (Phengodidae), starworm (Rhagophthalmidae), and click-beetle (Pyrophorini) bioluminescent systems. It is the substrate of luciferase, which is responsible for the characteristic yellow light emission from many firefly species.

A photocyte is a cell that specializes in catalyzing enzymes to produce light (bioluminescence). Photocytes typically occur in select layers of epithelial tissue, functioning singly or in a group, or as part of a larger apparatus. They contain special structures termed as photocyte granules. These specialized cells are found in a range of multicellular animals including ctenophora, coelenterates (cnidaria), annelids, arthropoda and fishes. Although some fungi are bioluminescent, they do not have such specialized cells.

In enzymology, a Latia-luciferin monooxygenase (demethylating) (EC 1.14.99.21) is an enzyme that catalyzes the chemical reaction

In enzymology, a Cypridina-luciferin 2-monooxygenase (EC 1.13.12.6) is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">Renilla-luciferin 2-monooxygenase</span>

Renilla-luciferin 2-monooxygenase, Renilla luciferase, or RLuc, is a bioluminescent enzyme found in Renilla reniformis, belonging to a group of coelenterazine luciferases. Of this group of enzymes, the luciferase from Renilla reniformis has been the most extensively studied, and due to its bioluminescence requiring only molecular oxygen, has a wide range of applications, with uses as a reporter gene probe in cell culture, in vivo imaging, and various other areas of biological research. Recently, chimeras of RLuc have been developed and demonstrated to be the brightest luminescent proteins to date, and have proved effective in both noninvasive single-cell and whole body imaging.

In enzymology, a Watasenia-luciferin 2-monooxygenase (EC 1.13.12.8) is an enzyme that catalyzes the chemical reaction

In enzymology, a Renilla-luciferin sulfotransferase is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">Bioreporter</span> Genetically engineered microbial cells

Bioreporters are intact, living microbial cells that have been genetically engineered to produce a measurable signal in response to a specific chemical or physical agent in their environment. Bioreporters contain two essential genetic elements, a promoter gene and a reporter gene. The promoter gene is turned on (transcribed) when the target agent is present in the cell’s environment. The promoter gene in a normal bacterial cell is linked to other genes that are then likewise transcribed and then translated into proteins that help the cell in either combating or adapting to the agent to which it has been exposed. In the case of a bioreporter, these genes, or portions thereof, have been removed and replaced with a reporter gene. Consequently, turning on the promoter gene now causes the reporter gene to be turned on. Activation of the reporter gene leads to production of reporter proteins that ultimately generate some type of a detectable signal. Therefore, the presence of a signal indicates that the bioreporter has sensed a particular target agent in its environment.

<span class="mw-page-title-main">Coelenterazine</span> Chemical compound

Coelenterazine is a luciferin, a molecule that emits light after reaction with oxygen, found in many aquatic organisms across eight phyla. It is the substrate of many luciferases such as Renilla reniformis luciferase (Rluc), Gaussia luciferase (Gluc), and photoproteins, including aequorin, and obelin. All these proteins catalyze the oxidation of this substance, a reaction catalogued EC 1.13.12.5.

<span class="mw-page-title-main">Vargulin</span> Chemical compound

Vargulin, also called Cypridinid luciferin, Cypridina luciferin, or Vargula luciferin, is the luciferin found in the ostracod Cypridina hilgendorfii, also named Vargula hilgendorfii. 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.

<i>Vargula hilgendorfii</i> Species of seed shrimp

Vargula hilgendorfii, sometimes called the sea-firefly and one of three bioluminescent species known in Japan as umi-hotaru (海蛍), is a species of ostracod crustacean. It is the only member of genus Vargula to inhabit Japanese waters; all other members of its genus inhabit the Gulf of Mexico, the Caribbean Sea, and waters off the coast of California. V. hilgendorfii was formerly more common, but its numbers have fallen significantly.

<span class="mw-page-title-main">Dinoflagellate luciferase</span>

Dinoflagellate luciferase (EC 1.13.12.18, Gonyaulax luciferase) is a specific luciferase, an enzyme with systematic name dinoflagellate-luciferin:oxygen 132-oxidoreductase.

References

    1. DeLuca, M., Dempsey, M. E., Hori, K., Wampler, J. E., & Cormier, M. J. (1971). Mechanism of oxidative carbon dioxide production during Renilla reniformis bioluminescence. Proceedings of the National Academy of Sciences, 68(7), 1658-1660.
    2. Shimomura O, Masugi T, Johnson FH, Haneda Y (1978). "Properties and reaction mechanism of the bioluminescence system of the deep-sea shrimp Oplophorus gracilorostris". Biochemistry. 17 (6): 994–8. doi:10.1021/bi00599a008. PMID   629957.
    3. Shimomura O, Masugi T, Johnson FH, Haneda Y (1978). "Properties and reaction mechanism of the bioluminescence system of the deep-sea shrimp Oplophorus gracilorostris". Biochemistry. 17 (6): 994–8. doi:10.1021/bi00599a008. PMID   629957.
    4. Inouye, S., & Sasaki, S. (2007). Overexpression, purification and characterization of the catalytic component of Oplophorus luciferase in the deep-sea shrimp, Oplophorus gracilirostris. Protein expression and purification, 56(2), 261-268.
    5. Hall, M. P., Unch, J., Binkowski, B. F., Valley, M. P., Butler, B. L., Wood, M. G., ... & Robers, M. B. (2012). Engineered luciferase reporter from a deep sea shrimp utilizing a novel imidazopyrazinone substrate. ACS chemical biology, 7(11), 1848-1857
    6. Inouye, S., Sahara-Miura, Y., Sato, J. I., Iimori, R., Yoshida, S., & Hosoya, T. (2012). Expression, purification and luminescence properties of coelenterazine-utilizing luciferases from Renilla, Oplophorus and Gaussia: comparison of substrate specificity for C2-modified coelenterazines. Protein Expression and Purification, 88(1), 150-156.
    7. Inouye, S., Sato, J. I., Sahara-Miura, Y., Hosoya, T., & Suzuki, T. (2014). Unconventional secretion of the mutated 19 kDa protein of Oplophorus luciferase (nanoKAZ) in mammalian cells. Biochemical and biophysical research communications, 450(4), 1313-1319.
    8. Tomabechi, Y., Hosoya, T., Ehara, H., Sekine, S. I., Shirouzu, M., & Inouye, S. (2016). Crystal structure of nanoKAZ: The mutated 19 kDa component of Oplophorus luciferase catalyzing the bioluminescent reaction with coelenterazine. Biochemical and biophysical research communications, 470(1), 88-93.