Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.14.14.3 (luciferase)
 38,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Light-induced ATP synthesis was studied in intact cells and chromatophores of Erythrobacter sp. strain OCh114. ATP synthesis was measured by both the pH method and the luciferin-luciferase luminescence method. The rate of ATP synthesis was moderate (a typical value of 0.65 mol of ATP per mol of bacteriochlorophyll per min), and synthesis was inhibited by antimycin A. ATP was synthesized under illumination only under aerobic conditions and not under anaerobic conditions. This characteristic was similar to that of other light-induced energy transduction processes in this bacterial species, such as oxidation of reaction center, oxidation of cytochrome c551, and translocation of H+, which were not observed under anaerobic conditions. This phenomenon was reconciled with the fact that the Erythrobacter sp. could not grow anaerobically even in the light. The characteristics of oxidative phosphorylation and ATP hydrolysis were also investigated. The respiratory ratio of chromatophores was 2.3. Typical rates of oxidative phosphorylation by NADH and by succinate were 2.9 mol of ATP per mol of bacteriochlorophyll per min (P/O = 0.22) and 1.1 mol of ATP per mol of bacteriochlorophyll per min (P/O = 0.19), respectively. A typical rate of ATP hydrolysis was 0.25 mol of ATP per mol of bacteriochlorophyll per min in chromatophores. ATPase and adenylate kinase are also involved in the metabolism of adenine nucleotides in this bacterium.
 ...
PMID:Photophosphorylation and oxidative phosphorylation in intact cells and chromatophores of an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh114. 378 35

Up to now, more than 40.000 determinations of urinary estrogens (E1 + E2) have been carried out in routine clinical analysis by the enzymatic method using estradiol dehydrogenase. This method makes use of the transhydrogenating activity of the placental enzyme: this enzyme transfers hydrogen from NADP to NAD with recycling of the specific substrate (E1 + E2). For several years the necessary reagents have been commercially available in the form of a kit. Nonetheless, various improvements have been made to the measurement of reduced NAD, which accumulates in the reaction medium and is directly proportional to the concentration of the two estrogens. Three protocols are available at present: Spectrophotometric measurement at 340 nm (initial technique); Colorimetric measurement at 492 nm. The pink colour measured arises from the reduction of a tetrazolium salt (INT) by reduced NAD in a coupled system using diaphorase; Measurement by bioluminescence of the light energy liberated on the reduction of flavin derivatives by NADH. The reaction is mediated by various enzymes isolated from marine bacteria (FMN oxidoreductase and luciferase) in the presence of an aliphatic aldehyde (decanal). The procedure for each of these protocols is described as well as the means for controlling the linearity of the reaction. The choice of protocol is determined by the biological fluid available, the speed of response desired and the cost of the analysis.
 ...
PMID:[Various protocols for determining estrogens by the enzymatic method using estradiol dehydrogenase. Respective procedures and advantages]. 386 35

The luminous bacteria Beneckea Harveyi were immobilized on BrCN-sepharose and cellulose films activated with cyanuric chloride. Preparations with high luciferase and FMN-reductase activities were obtained, which showed no background luminescence without NADH being added. The storage conditions for the preparations obtained were optimized, and their kinetic parameters and thermostability were studied. Standard curves for NADH determining within the concentration range 1 nM-1 microM were plotted with the detection level of 1 picomol NADH. The preparations are very promising for bioluminescent assay due to their high activity, simple production, high stability during storage and a possibility for the repeated use.
 ...
PMID:[Bioluminescent method of determining picomolar amounts of nicotinamide-adenine dinucleotide using an immobilized extract of the luminescent bacterium Beneckea harveyi]. 387 52

A semiautomatic determination of glycerol is described, in which luminescence produced by bacterial NADH-linked luciferase is measured by an automatic luminescence analyser (Berthold LB 950 T). The glycerol determination is based on the enzymatic conversion of glycerol to 3-phosphoglycerate, made irreversible by the presence of arsenate. NADH, formed in the glycerol-3-phosphate and glyceraldehyde-3-phosphate dehydrogenase reactions, is subsequently determined by the bacterial luciferase system. Stable kinetics of light emission were obtained by reducing the catalytic concentration of NAD(P)H: FMN oxidoreductase from 85 U/1 to 8.5 U/1. This method was applied to serum samples and validated by comparison with an enzymatic fluorimetric method. The new method is approximately 10 times more sensitive than the fluorimetric one. Moreover, it is simpler, more convenient, less time consuming and also less expensive than spectrophotometric, fluorimetric or radiochemical methods used for glycerol determination.
 ...
PMID:Semiautomatic bioluminescence determination of glycerol using a computer controlled luminescence analyser (Berthold LB 950 T). 398 81

A method for antiprotease activity measurement based on the use of luminous bacteria luciferase as protein substrate of proteases is suggested. Antiprotease is incubated with protease for 1 to 2 min at 30 degrees C and then it is added to the reaction mixture containing luciferase, NADH: FMN-oxidoreductase and their substrates--myristic aldehyde, FMN and NADH. Biofluorescence is measured in a temperature-controlled cuvette for 1 min. The total time of the measurement is 3 min. The method can be applied both in fine biochemical assays and in medical rapid diagnosis.
 ...
PMID:[Bioluminescent method of determining antiprotease activity]. 406 17

The NADH-dependent and NADPH-dependent oxidoreductase activities associated with bacterial luciferase in Vibrio (Beneckea) harveyi can simultaneously be removed from purified luciferase through a Blue Sepharose CL-6B column. The result achieved with this one-step affinity chromatography is similar to that obtained with two sequential "reverse-affinity" chromatographies.
 ...
PMID:Separation of bacterial luciferase from oxidoreductases by affinity chromatography. 409 Dec 72

A new method for extracting pyridine nucleotides from tissue samples at room temperature that allows the simultaneous extraction of both the oxidized and reduced nucleotide when using a 70% buffered ethanol solution as the extractant has been developed. The extraction efficiencies for NAD+ and NADH were 91 and 102%, respectively. The extraction method was followed by a combined bioluminescent assay of both nucleotides. A bacterial bioluminescent system, which included luciferase and low levels of a NADH-specific oxidoreductase, was used to produce a constant light intensity directly proportional to the amount of NADH in the tissue extract sample. When the NADH had been measured, the NAD+ present in the extract was enzymatically converted to NADH by the addition of alcohol dehydrogenase, after which the second increase in light level was recorded. The sensitivity of the bioluminescent assay presented here is 5 X 10(-14) mol NADH or NAD+ per assay.
 ...
PMID:Simultaneous extraction and combined bioluminescent assay of NAD+ and NADH. 634 64

A simple, highly specific, and sensitive bioluminescent method for determination of free fatty acids in unextracted plasma or serum has been developed. The method is based on the activation of free fatty acids by acyl-CoA synthetase (EC 6.2.1.3). The pyrophosphate formed is used to phosphorylate fructose 6-phosphate in a reaction catalyzed by the enzyme pyrophosphate-fructose-6-phosphate phosphotransferase (EC 4.1.2.13). The triosephosphates produced from fructose 1,6-bisphosphate by aldolase are oxidized by NAD in the presence of arsenate to 3-phosphoglycerate. The NADH is detected via the bacterial NADH-linked luciferase system. Excellent agreement has been obtained by comparison with accepted methods. In addition, for the determination of serum free fatty acids, the method is particularly applicable for following lipolysis of isolated adipocytes.
 ...
PMID:Bioluminescent determination of free fatty acids. 648 22

A bioluminescent assay based on the bacterial luciferase reaction has been developed for the determination of total lactate dehydrogenase and heart-specific lactate dehydrogenase isoenzyme-1 activity in serum. The lactate dehydrogenase-catalyzed reaction was measured in both directions, but NADH formation (lactate----pyruvate) is recommended because it allows the use of optimal reaction conditions. Internal calibration with a known amount of NADH accounts for possible interference from samples when both NADH formation and consumption are followed. The bioluminescent method is sensitive, has good precision, and is readily automated. Serum lactate dehydrogenase isoenzyme-1 was immunochemically isolated and the activity was assayed by bioluminescence. A good correlation between the bioluminescent assays and the conventional spectrophotometric procedure used as reference was obtained.
 ...
PMID:Bioluminescent assay of lactate dehydrogenase and its isoenzyme-1 activity. 653 46

This simple, rapid, sensitive kinetic bioluminescent method for the assay of bile acids in serum involves use of 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) in combination with a new, commercially available NADH Monitoring Reagent (LKB-Wallac) containing a low activity of NADH:FMN-oxidoreductase and a high activity of bacterial luciferase. Interfering dehydrogenases in serum are inactivated in the test tube with trichloroacetic acid before the assay. The standard curve is linear for concentrations of bile acids up to about 300 mumol/L. With a sample volume of 20 microL, the detection limit is about 0.2 mumol/L. The within-run precision (CV) is about 10%, both at high and low concentrations of bile acids in serum. Correlation is good (r = 0.996) between results by this method and an enzymatic method based on spectrophotometry. However, the latter method is considerably less sensitive, and it is less precise at low concentrations of bile acids.
 ...
PMID:Bioluminescent assay for total bile acids in serum with use of bacterial luciferase. 657 77


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>