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Topic: Aequorin

	Fluorescent proteins: Introduction (Site not responding. Last check: 2007-11-03)
		Aequorin was originally obtained by purification from the jellyfish Aequorea victoria, but now it is prepared more efficiently using recombinant techniques.
		The active aequorin is formed by a complex between apoaequorin (APO), oxygen and coelenterazine.
		Reconstitution of aequorin can be done using the native coelenterazine or analogs (some analogs with quicker response and more intese signal have been described and are comercially available).
	www.sct.ub.es:802 /Tutorial/proteins/aequorin.htm (194 words)

	Bioluminescence and Secondary Structure Properties of Aequorin Mutants Produced for Site-Specific Conjugation and ...
		Aequorin is one of several photoproteins that emits visible light upon binding to calcium ions.
		To further extend the application of aequorin in bioanalytical methods, we have explored the feasibility of producing a mutant of aequorin (i.e., one containing a single cysteine residue) suited for site-specific conjugation of nonpeptidic molecules and site-specific immobilization of the protein onto a surface.
		The mutant aequorin solution is assumed to be completely saturated with calcium ions as soon as it is added to the quartz cell, thus, producing a constant luminescence signal over the required time period of 3-4 min.
	pubs.acs.org /cgi-bin/jtextd?bcches/11/i01/html/bc9900800.html (4483 words)

	Quincy Bioscience Amyotrophic Lateral Sclerosis (Site not responding. Last check: 2007-11-03)
		Aequorin could provide a neuroprotective role in ALS by buffering calcium ions that cannot be handled correctly due to a deficiency in endogenous calcium-binding proteins.
		In order to test the potential benefits of aequorin, it is necessary to begin by investigating the feasibility of introducing aequorin into neurons in a series of in vitro and in vivo studies.
		After evaluating the effects of aequorin on neuron survival, the long-term effects of aequorin treatment will be studied to demonstrate (a) how long it remains in neurons and (b) whether there are any negative side effects with long-term exposure to aequorin.
	www.qrgbioscience.com /bioscienceals.html (778 words)

	Aequorin-based measurements of intracellular Ca2+-signatures in plant cells
		Aequorin is a Ca -binding photoprotein composed of an apoprotein (apoaequorin) which has an approximate molecular weight of 22 kDa and a prosthetic group, a luciferin molecule, coelenterazine (MW 432).
		Again, the residual aequorin was completely discharged and the resulting luminescence was used to estimate the total amount of aequorin present in various experiments in order to determine the rate of aequorin consumption.
		Combining the Ca sensitivity of aequorin and the fluorescence of GFP, the fusion protein enables to visualize calcium signals in a single neuroblastoma cell using an intensified CCD camera (29).
	www.biologicalprocedures.com /bpo/arts/1/40/m40.htm (6473 words)

	Technological Background
		Aequorin has been used extensively, most notably for the detection of calcium concentrations in vivo and as a label in immunoassays.
		We use aequorin as a highly sensitive label in multiple assays and biosensors to detect the concentration of various physiologically relevant analytes, such as cortisol, prostacyclin, angiotensin, and vasopressin.
		To develop the assay, the analyte of interest is either chemically or genetically conjugated to aequorin, depending upon the characteristics of the analyte.
	www.senseomics.com /tech.htm (824 words)

	page2
		Aequorin, a calcium-specific indicator, was regenerated in vivo from apoaequorin produced in the cells by incubation with coelenterazine.
		Aequorin expressing cells treated with agonists of endogenous receptors were used in luminescence measurements to demonstrate that the reporter lines offer a highly sensitive and robust means of assaying changes in the concentration of cytosolic Ca2+ ion.
		Aequorin is a calcium-sensitive luminescent protein from the coelenterate Aequorea victoria (A. forskalea) which is formed from apoaequorin, a polypeptide of relative molecular mass approximately 22,000, and coelenterazine, a hydrophobic luminophore.
	www.nanolight.com /butref.HTM (5740 words)

	Aequorin: Genetic Music
		The jellyfishat the left was taken from a recent article in Nature describing the tertiarystructure of one of the Aequorins: James F. Head*, Satoshi Inouye,Katsunori Teranish and Osamu Shimomura.
		The 3-Dmodel of Aequorin displayed here is from a different member of theAequorin family.
		The primary structure of this Aequorin, on which the musicis based, is given in the table below, with Calmodulin for comparison.
	www.whozoo.org /mac/Music/Aequorin.html (307 words)

	Assembly of Chimeric Connexin-Aequorin Proteins into Functional Gap Junction Channels. REPORTING INTRACELLULAR AND ... (Site not responding. Last check: 2007-11-03)
		the amino terminus of aequorin to the carboxyl terminus of connexins.
		Construction of Connexin-Aequorin Chimeric cDNAs-- Aequorin was fused in frame to the COOH terminus of Cx26 (23), Cx32 (24), and Cx43 (25) using a two-step PCR procedure
		The orientation of the chimerae in the endoplasmic reticulum was examined by determining the aequorin activity of Cx32-Aeq
	www.jbc.org /cgi/content/full/273/3/1719 (5664 words)

	UWM brain research supports drug development from jellyfish protein
		Aequorin, the jellyfish protein, appears to be a viable substitute.
		He became interested in aequorin as an undergraduate at UW-Milwaukee, after reading an article that linked the stings of jellyfish with the symptoms of multiple sclerosis, a disease of the central nervous system that his mother has.
		Aequorin was discovered in the 1960s and has been used in research for a long time as an indicator of calcium.
	www.eurekalert.org /pub_releases/2006-10/uow--ubr102706.php (584 words)

	Research Interests of the Daunert Group (Site not responding. Last check: 2007-11-03)
		The use of bioluminescent photoproteins, such as aequorin, as labelscan circumvent this limitation of conventional chemiluminescence assays.Aequorin is a calcium-activated photoprotein found in Aequorea victoria(jellyfish), and it can be used as a biological Ca2+ indicator.
		In ourlaboratory we use aequorin as a bioluminescent label in the developmentof novel competitive binding assays for biomolecules by taking advantageof the selective interaction between biological binders (antibodies, bindingproteins, receptors, etc.) and ligands.
		Moreover, we were ableto detect 4 attomol of biotin (vitamin H) by using aequorin as a labelin a homogeneous competitive binding assay.
	www.chem.uky.edu /research/daunert (484 words)

	Science Supplemental Material--Falciatore et al.
		Upon complete Ca binding, aequorin undergoes an irreversibile reaction, with emission of light in the visible range (peak at 470 nm) and the consequent consumption of the active photoprotein.
		The fractional rate of aequorin consumption at a given photoprotein concentration is proportional, in the physiological pCa range, to free calcium that can react with the protein; i.e., that is not tightly bound to other molecules or accumulated in Ca stores.
		Aequorin was reconstituted in vivo by incubating 1
	www.sciencemag.org /feature/data/1048586.dtl (1099 words)

	News & Events - News Releases
		Since his discovery of aequorin 38 years ago, Shimomura's life's work has been devoted to shedding light on luminescence-a complex chemical reaction within an organism's cells that results in the release of energy in the form of light instead of heat.
		This discovery led to the use of aequorin as an important biomedical tool for tracking the movement of calcium within cells.
		Now that Shimomura and his colleagues know the exact structure of aequorin, they'll be better able to study how the protein functions in concert with other chemicals, and, possibly, enhance its usefulness as a biological marker.
	www.bu.edu /phpbin/news/releases/display.php?id=252 (486 words)

	BioMed Central \| Full text \| A new short-term toxicity assay using Aspergillus awamoriwith recombinant aequorin gene
		The recombinant aequorin gene from the jellyfish Aequorea victoria responsible for the expression of the Ca -sensitive aequorin photoprotein has been cloned in the filamentous fungus Aspergillus awamori.
		Aequorin is a Ca -sensitive photoprotein of the jellyfish Aequorea victoria (Mr = 21,400) [11].
		With different parameters available for analysis in the aequorin test it could be useful to assess the toxicity by calculating the NOEC (no observable effect concentration) or a nominal IC value [22].
	www.biomedcentral.com /1471-2180/5/40 (4089 words)

	UniProtKB/Swiss-Prot entry P07164 [AEQ1_AEQVI] Aequorin-1
		Charbonneau H. Walsh K.A. McCann R.O. Prendergast F.G. Cormier M.J. Vanaman T.C. "Amino acid sequence of the calcium-dependent photoprotein aequorin.";
		: The reduction of the disulfide bond is necessary to regenerate aequorin from apoaequorin.
		Aequorin has a number of advantages over other Ca(2+) indicators, for example, low leakage rate from cells, lack of intracellular compartmentalization or sequestration and it does not disrupt cell functions or embryo development.
	ca.expasy.org /uniprot/P07164 (388 words)

	Glucose-stimulated Insulin Secretion Correlates with Changes in Mitochondrial and Cytosolic Ca2+ in Aequorin-expressing ...
		For analysis of aequorin expression, cells were plated on coverslips as described by Rutter et al.
		expression of aequorin in a subset of mitochondria.
		Aequorin luminescence measurements of INS-1 EK-3 and C-29 cells stimulated with 20 mM KCl.
	www.jci.org /cgi/content/full/98/11/2524 (6369 words)

	wisbusiness (Site not responding. Last check: 2007-11-03)
		Aequorin might also be able to able to help stroke patients and people who have multiple sclerosis (MS).
		Although aequorin has been used for years in scientific assays to measure calcium levels in cells, Moyer said it has not been tested to see if it could restore calcium homeostasis or balance.
		Moyer said he has begun working with rats to determine if there is any improvement in cognitive decline once they have had aequorin injected into their brains.
	www.wisbusiness.com /index.iml?Article=33575 (1249 words)

	[No title]
		Aequorin is the active photoprotein containing partially oxidized Coelenterazine (FW 423.5) complexed with 2 oxygen atoms (MW 32) to make a stable complex when dry of FW=22,727.2.
		Aequorin powder or liquid suspension when accidentally mixed with Calcium as a result of powder residues left on the clothes or hands of employees or on the surfaces of packaging machines will cause the product to emit its stored light energy and will revert the Aequorin complex back to Apoaequorin, Coelenteramide, and Carbon Dioxide.
		Spent Aequorin may be regenerated and the light emitting reaction is reversible by incubation of Apoaequorin and fresh Coelenterazine in the presence of a mild reducing agent, and in suitable physiologic buffers.
	www.nanolight.com /downloads/307_307A_307B_307C_308_MSDS.doc (1253 words)

	Citric acid cycle intermediates as ligands for orphan G-protein-coupled receptors : Nature
		The activity of each fraction was assayed by the aequorin assay in CHO cells transfected with GPR91 (fl bars) or control plasmid (grey bars).
		GPR91 was selectively activated by succinate but not by other citric acid cycle intermediates (Supplementary Information) or any of a collection of 800 pharmacologically active compounds and known GPCR ligands tested (data not shown).
		Aequorin luminescence was recorded with a Microlumat (Berthold).
	www.nature.com /uidfinder/10.1038/nature02488 (3597 words)

	Use of aequorin GFP fused protein
		Aequorin is a photoprotein isolated from the bioluminescent jellyfish Aequorea victoria.
		Researchers at the Institut Pasteur have constructed several hybrid proteins, using GFP and aequorin genes.
		The coupling of these two bioluminescent proteins is particularly useful for calcium detection, because when calcium binds to aequorin, GFP emits its characteristic green light by chemoluminescent energy transfer (CRET).
	www.pasteur.fr /applications/dri/English/DI/98.03.html (401 words)

	Aequorin - flies that glow in the dark! (Site not responding. Last check: 2007-11-03)
		Aequorin is a photoprotein originally characterised in the luminescent jellyfish Aequorea victoria.
		As the dynamic range of calcium signalling concentrations in jellyfish is very similar to those in plants and animals generally (50-500 nM), this means that aequorin is a useful calcium indicator.
		Aequorin was first used by direct extraction from jellyfish and microinjection, but over the last decade, recombinant aequorin has become available, and it has also been used as a transgene, originally in plants.
	www.mblab.gla.ac.uk /tubules/aequorin.html (474 words)

	Expression and Secretion of Aequorin as a Chimeric Antibody by Means of a Mammalian Expression Vector -- Casadei et al. ... (Site not responding. Last check: 2007-11-03)
		Initially the cDNA of the photoprotein aequorin from Aequorea victoria was cloned and expressed in Escherichia coli.
		The gene was expressed as apoaequorin and, by using luciferin isolated from Renilla reniformis, its activity was found essentially identical to native aequorin.
		The aequorin gene was subcloned into a mammalian expression vector to produce a fusion protein directing secretion of apoaequorin; the aequorin gene was fused to the 3' terminus of an immunoglobulin heavy-chain gene that directed expression of an anti-4-hydroxy-3-nitrophenacetyl antibody.
	www.pnas.org /cgi/content/abstract/87/6/2047 (333 words)

	Use of the Ca2+ reporter GFP-aequorin for probing infection and physiology
		Aequorin, a genetically encoded luminescent reporter, has been used for measuring intracellular concentrations of Ca2+.
		However, the amount of light produced by aequorin is very low.
		When Ca2+ binds to aequorin, GFP emits its characteristic green light by chemoluminescent energy transfer (CRET), without a need for light excitation.
	www.pasteur.fr /applications/dri/English/DI/04-97.htm (515 words)

	Decrease in Ca2+-Sensitizing Effect of UD-CG 212 Cl, a Metabolite of Pimobendan, under Acidotic Condition in Canine ...
		Aequorin light signals were detected with a photomultiplier (9789A; Thorn EMI Electron Tubes, Ruislip, UK) and light signals
		on aequorin light transients (tracings with faster rate of rise) and of isometric contractions (tracings with slower rate of rise).
		Takahashi R, Talukder MA and Endoh M (2000b) Effects of OR-1896, an active metabolite of levosimendan, on contractile force and aequorin light transients in intact rabbit ventricular myocardium.
	jpet.aspetjournals.org /cgi/content/full/298/3/1060 (4549 words)

	Biochemical Light Emission
		Here you find a model of the structure of aequorin with the coelenterazine hydroperoxide bound prior to the binding of calcium ions.
		This may be accomplished by absorbing the light by some chromophore and splitting the energy into a less energetic photon and thermal energy dissipated as heat.
		Organisms employing aequorin as primary light source face the problem of redshifting the generated light by a substance called green fluorescent protein (GFP).
	www.biologie.uni-hamburg.de /lehre/bza/light/introlight.htm (663 words)

	Lack of Direct Role for Calcium in Ischemic Diastolic Dysfunction in Isolated Hearts -- Eberli et al. 102 (21): 2643 -- ... (Site not responding. Last check: 2007-11-03)
		Aequorin was macroinjected with a technique previously described for
		Aequorin light signals were recorded on a 4-channel recorder.
		Aequorin measurements of free calcium in single heart cells.
	circ.ahajournals.org /cgi/content/full/102/21/2643 (3425 words)

	Quincy Bioscience Enters the Southeastern Wisconsin Biotech Arena (Site not responding. Last check: 2007-11-03)
		The company develops therapeutics that address the imbalance of calcium ions commonly thought to be related to the neuronal degeneration seen in such diseases of aging.
		While aequorin is a commonly used tool in biotechnology research, to date it has not been utilized in any therapeutic manner, setting Quincy Bioscience's technology apart.
		Quincy Bioscience is investigating aequorin for its potential to restore the balance of that critical ion in the human body.
	www.qrgbioscience.com /7_12_04pressrelease.html (276 words)

	Ca2+ Homeostasis in the Endoplasmic Reticulum: Coexistence of High and Low [Ca2+] Subcompartments in Intact HeLa Cells ...
		Relationship between the drop in aequorin luminescence induced by histamine and the level of aequorin consumption at the moment
		Transfected aequorin in the measurement of cytosolic Ca concentration ([Ca ]c).
		Aequorin targeted to the endoplasmic reticulum reveals heterogeneity in luminal Ca concentration and reports agonist- or IP -induced release of Ca Mol.
	www.jcb.org /cgi/content/full/139/3/601 (7859 words)

	Measurement of Intracellular Calcium -- Takahashi et al. 79 (4): 1089 -- Physiological Reviews
		Aequorin, isolated from the jellyfish Aequore forskålea (353, 355), is the most popular bioluminescent Ca indicator.
		When cells in suspension are used, the gravity-loading technique may be the easiest available to load aequorin (37).
		Another calibration procedure for aequorin is based on the rate of aequorin consumption.
	physrev.physiology.org /cgi/content/full/79/4/1089 (9338 words)

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