Where results make sense

About us   |   Why use us?   |   Reviews   |   PR   |   Contact us

Topic: Catechol oxidase

    Note: these results are not from the primary (high quality) database.

Crystal structure of a plant catechol oxidase containing a dicopper center - Nature Structural & Molecular Biology Catechol oxidases and hemocyanins show no significant sequence similarity and no resemblance in their overall fold, except for the catalytic core which is remarkably similar in both proteins. Catechol oxidases are ubiquitous plant enzymes containing a dinuclear copper center. The side chains of catechol oxidase are colored by atom type and the metal-ligating histidine residues of lpHC are shown in green. www.nature.com /nsmb/journal/v5/n12/full/nsb1298_1084.html

Catechol Oxidase In the presence of catechol oxidase, catechol is converted to benzoquinone. PTU is known to combine with the copper in catechol oxidase and inhibit its enzymatic activity. In the presence of oxygen, catechol oxidase catalyzes the removal of electrons and hydrogens from catechol, a phenolic compound found in plant cells. www.science-projects.com /co.htm

Inhibition of NAD(P)H Oxidase Activity Blocks Vascular Endothelial Growth Factor Overexpression and Neovascularization during Ischemic Retinopathy -- Al-Shabrawey et al. 167 (2): 599 -- American Journal of Pathology Stolk J, Hiltermann TJ, Dijkman JH, Verhoeven AJ: Characteristics of the inhibition of NADPH oxidase activation in neutrophils by apocynin, a methoxy-substituted catechol. NAD(P)H oxidase by interfering with the assembly of the cytosolic Fu XW, Wang D, Nurse CA, Dinauer MC, Cutz E: NADPH oxidase is an O2 sensor in airway chemoreceptors: evidence from K+ current modulation in wild-type and oxidase-deficient mice. ajp.amjpathol.org /cgi/content/full/167/2/599   (5170 words)

Practical Activities- Inhibition of catechol oxidase in banana by heavy metals This reaction is due to the enzyme catechol oxidase which converts catechol to a yellow pigment. The enzyme, catechol oxidase, is present in the clear liquid in the beaker. Formation of a yellow pigment indicates the enzyme in the banana extract is active and is acting on the catechol. www-saps.plantsci.cam.ac.uk /worksheets/activ/prac2.htm   (5170 words)

Papaine, Amylase, Catalase, Lactase, Catechol Oxidase Enzymes With catechol oxidase (aka tyrosinase), we will move one step further into enzymology and look at how inhibitors can control the enzyme. Today you will become acquainted with several common enzymes (amylase, catalase, lactase, papaine and catechol oxidase) from very common sources. These four enzymes were chosen because they are observed by using four different strategies. www.science-projects.com /CC101L5.htm   (5170 words)

Effect of inhibition of MAO and COMT on intrarenal dopamine and serotonin and on renal function -- Wang et al. 280 (1): 248 -- AJP - Regulatory, Integrative and Comparative Physiology The purpose of the present investigation was to study the effects of inhibition of monoamine oxidase (MAO) and/or catechol- O -methyltransferase Inhibition of catechol- O -methyltransferase by 1-vinyl derivatives of nitrocatechols and nitroguaiacols. Different renal effects of two inhibitors of catechol- O -methylation in the rat: entacapone and CGP 28014. ajpregu.physiology.org /cgi/content/full/280/1/R248   (5170 words)

catechol-o-methyl_transferase Dopamine is metabolized by monoamine oxidase and catechol-O-methyl transferase. Catechol-o-Methyl Transferase Cathepsin D Cholesterol Esterase Chymotrypsin d-Amino Acid Oxidase d-Glucose-6-Phosphate Deoxyribonuclease (DNase) Deoxyribonucleic Acid (DNA) Elastase... The effect of catechol-O-methyl transferase inhibition by entacapone on the pharmacokinetics and metabolism of levodopa in healthy... catechol-o-methyl_transferase.networklive.org   (5170 words)

Enzymes Hydroquinone has a very similar structure to catechol yet catechol oxidase will not use it as a substrate. For the reaction to occur, you must have both the substrate (catechol) and an enzyme source (potato extract) in the same tube. Enzymes are most active at the pH of their natural environment. www.utdallas.edu /~msweet/bioenz.htm   (5170 words)

Dopamine and quinone The catechol of the carcinogenic synthetic estrogen hexestrol, a hydrogenated derivative of diethylstilbestrol, is metabolized to its quinone, which reacts with DNA to form depurinating adducts at the N-7 of guanine and N-3 of adenine. "X-ray snapshots of quinone cofactor biogenesis in bacterial copper amine oxidase." Nat Struct Biol 9(8): 591-6. Catechol estrogens and catecholamines are metabolized to quinones, and the metabolite catechol (1,2-dihydroxybenzene) of the leukemogenic benzene can also be oxidized to its quinone. lansbury.bwh.harvard.edu /dopamine_and_quinone.htm   (5883 words)

Poison Oak ne of the authors (WLE) has studied an even more specific and potent oxidase for urushiol called catechol 2,3 oxidase. An urushiol residue on the skin is difficult to wash off and may be spread by scratching. If 2 micrograms of urushiol is sufficient to initiate a reaction in one hypersensitive person, then 1000 micrograms of urushiol (2 X 500) could initiate reactions in 500 hypersensitive people. waynesword.palomar.edu /ww0802.htm   (5883 words)

ARS Publication request: Tissue Localization of Cytokinin Dehydrogenase in Maize:possible Involvement of Quinone Species Generated from Plant Phenolics by Other Enzymatic Systems in the Catalytic Reaction The results reported here revealed that the electron acceptors may be generated in vivo from plant phenolics by other enzymatic systems such as peroxidase and tyrosinase/laccase/catechol oxidase. Histochemical localizations of cytokinin dehydrogenase by activity staining and immunochemistry using optical and confocal microscopy showed that cytokinin dehydrogenase is most abundant in the aleurone layer of maize kernels and in phloem cells of the seedling shoots. Cytokinin dehydrogenase was confirmed to be present in the apoplast of cells. www.ars.usda.gov /research/publications/publications.htm?SEQ_NO_115=170870   (571 words)

Catechol Oxidase (Tyrosinase) - Enzymes The noncompetitive inhibitor binds to the enzyme at a location away from the active site, either blocking access to the active site or changing the conformation of the enzyme, rendering it inactive. Competitive inhibition can be reversed if the concentration of substrate is raised to sufficiently high levels while the concentration of the inhibitor is held constant (Figure3). Competitive inhibition takes place when a molecule that is structurally similar to the substrate for a particular reaction competes for a position at the active site on the enzyme. www.science-projects.com /Tyrosinase.htm   (571 words)

Catechol Oxidase (Tyrosinase) - Enzymes The noncompetitive inhibitor binds to the enzyme at a location away from the active site, either blocking access to the active site or changing the conformation of the enzyme, rendering it inactive. Either the noncompetitive inhibitor itself physically blocks the access to the active site, or it causes a conformational change in the protein, thus inactivating the active site. Because the substrate molecules cannot reverse the binding of a noncompetitive inhibitor, increasing the concentration of substrate will not reverse the inhibition. www.science-projects.com /Tyrosinase.htm   (571 words)

PharmGKB: Sympathetic Nerve Pathway In nerves, the pathways include both monoamine oxidase (MAOA and MAOB) and catechol-O-methyltransferase (COMT). In dopaminergic axons (nerves), catecholamine biosynthesis ends at dopamine, which is released and subject to reuptake by the dopamine transporter (DAT, SLC6A3). Catecholamines are also subject to metabolism in both nerves and in extraneuronal sites. www.pharmgkb.org /search/pathway/neurotransmitter/pre-post.jsp   (617 words)

Potato phenol oxidase We were watching the discussion about which root to use for catechol oxidase and is published by the John Hopkins University Press. Dave McNeely, Biology, University of Texas at Brownsville, 80 Fort Brown, biowww.clemson.edu /biolab/phenolox.html   (1059 words)

Apocynin, a plant-derived, cartilage-saving drug, might be useful in the treatment of rheumatoid arthritis -- Lafeber et al. 38 (11): 1088 -- Rheumatology Characteristics of the inhibition of NADPH oxidase activation in neutrophils by apocynin a methoxy sustituted catechol. rheumatology.oupjournals.org /cgi/content/full/38/11/1088   (1059 words)

104B-18 Halitosis inhibition ogainst methyl mercaptan by polyphenol oxidase of apple extracts Results The deodorizing activity of polyphenol oxidase on substrate specificity showed the high activities of 81.3% with chlorogenic acid and 36.8% with catechol. Halitosis inhibition ogainst methyl mercaptan by polyphenol oxidase of apple extracts 104B-18 Halitosis inhibition ogainst methyl mercaptan by polyphenol oxidase of apple extracts ift.confex.com /ift/2003/techprogram/paper_19129.htm   (307 words)

Questions MAO (monoamine oxidase) is an enzyme that breaks down the class of neurotransmitters called the catecholamines. If phenylalanine (a compound similar to the catechol structure except there are no hydroxyl groups bound to the benzene ring and there is a carboxyl group (COOH) bound to the same carbon containing the amine group), an enzyme, phenylalanine hydroxylase, adds an hydroxyl group to the benzene ring. The next step in the pathway involves the enzyme tyrosine hydroxylase, the rate limiting step in the entire process, which adds a (second) hydroxyl group to the aromatic ring. www.staff.washington.edu /chudler/questions.html   (307 words)

bg.html Finally, the actions of catecholamines in the synaptic cleft are terminated by selective reuptake into the axon terminal where they are either inactivated by the enzymes monoamine oxidase or catechol-O-methyl transferase or reloaded into synaptic vesicles for reuse. After interacting with postsynaptic receptors, the neurotransmitter must be cleared from the synaptic cleft in order for another round of transmission to occur. Once the neurotransmitter is released into the synaptic cleft it can produce a variety of postsynaptic effects, depending upon the nature of the receptors on the postsynaptic neuron. neuroscience.brown.edu /pkd/bg.html   (307 words)

Influence of hypo- and hyperthyroidism on noradrenaline metabolism in brown adipose tissue of the developing rat. We studied the noradrenaline content, and monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) activities in brown adipose tissue (BAT) of normal, hypothyroid, and hyperthyroid developing rat. In the newborn, thyroid hormones are necessary for the increase in noradrenaline content which occurs between 0 and 5 days. In the full-term fetus, hypothyroidism decreases noradrenaline content as in the newborn, and also decreases MAO and COMT activities. www.arclab.org /medlineupdates/abstract_7357045.html   (139 words)

MAO COMT, and GABA-T activities in primary astroglial cultures. Cultures from cerebral hemispheres of newborn rats contain the enzymes monoamine oxidase (MAO), catechol-O-methyltransferase (COMT), and gamma-aminobutyric acid alpha-ketoglutarate transaminase (GABA-T). The COMT activity was higher in the cultures than in adult rat cerebral hemispheres. www.arclab.org /medlineupdates/abstract_6848661.html   (164 words)

Allison C. Rice-Ficht The long term goals of the project include a study of i) the concerted expression of these proteins in development, ii) the biochemistry of shell formation including crosslink structure and enzymology of shell formation (tyrosine hydroxylase, catechol oxidase), and iii) the application of recombinant eggshell proteins and worm processes to synthetic microencapsulation. Fasciola hepatica eggshells are composed of at least three novel proteins which undergo the unusual post- translational modification of tyrosine to dihydroxyphenylalanine; this modification allows the proteins to undergo oxidation and crosslinking to form a hard, porous, quinone- tanned eggshell. Fasciola hepatica (liver fluke) stained with molybdate-nitrate reagent to detect the presence of DOPA containing protein, the precursor to eggshell. pauling.tamu.edu /medbiogen/arf.html   (164 words)

Catechol Oxidase (Tyrosinase) - Enzymes Other names for catechol oxidase are diphenol oxidase and tyrosinase. In these two types of animals with this enzyme that denatures at normal body temperatures, the black is formed only on the colder extremities of the body. Normal tyrosinase converts the amino acid tyrosine into melanine (black pigment). www.science-projects.com /Tyrosinase.htm   (164 words)

Try your search on: Qwika (all wikis)

About us   |   Why use us?   |   Reviews   |   Press   |   Contact us   Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.