Kinetic oxidases

Chemical kinetic methods have been applied to the quantitative analysis of a number of enzymes and substrates.One example, is the determination of glucose based on its oxidation by the enzyme glucose oxidase. ... 

Bateman, Jr. R. C. Evans, J. A. Using the Glucose Oxidase/Peroxidase Systems in Enzyme Kinetics, /. Chem. Educ. 1995, 72, A240-A241. 

Kinetic Constants for Wild-Type and Mutant Sulfite Oxidase ... 

Monoamine Oxidases and their Inhibitors. Table 2 Kinetic parameters of the two forms of monoamine oxidase... 

Escribano, J. et al., Characterization of monophenolase activity of table beet polyphenol oxidase determination of kinetic parameters on the tyramine/dopamine pair, J. Agric. Food Ghem., 45, 4209, 1997. 

Porras, A.G., Olson, J.S. and Palmer, G. (1981). The reaction of reduced xanthine oxidase with oxygen kinetics of peroxide and superoxide formation. J. Biol. Chem. 256, 9096-9103. 

Petersen LC. 1977. The effect of inhibitors on the oxygen kinetics of cytochrome c oxidase. Biochem Biophys Acta 460 299-307. 

Krebs and co-workers synthesized a series of dinuclear copper(II) complexes as models for catechol oxidase 91 (365) (distorted SP Cu-Cu 2.902 A), (366) (distorted five-coordinate geometry Cu-Cu 3.002A), (367) (distorted SP Cu-Cu 2.995 A), (368) (distorted five-coordinate geometry Cu-Cu 2.938 A), and (369) (distorted SP Cu-Cu 2.874 A). These complexes were characterized by spectroscopic and electrochemical methods. From kinetic analysis, a catalytic order for catecholase activity (aerial oxidation of 3,5 -di - ter t-buty lcatec h o 1) was obtained.326... 

FIGURE 8.9 Mitochondrial 02 and H2S consumption from non-limiting 02 to anoxic conditions, (a) Isolated mitochondria were exposed to repeated bouts of 12.5 pM H2S until anoxia was achieved, (b) At higher 02 levels, both 02 and H2S consumption events are coincident, but as the 02 levels decline the events become uncoupled and 02 consumption is limited first. The multiphasic kinetics of 02 consumption may result from transient inhibition of cytochrome c oxidase by H2S. Under anoxia, H2S consumption continues at a low level (after [36] reproduced with permission of the Company of Biologists). 

Enzyme containing Nation membranes prepared according to the proposed protocol have shown high specific activity and stability of immobilized glucose oxidase. As expected, the simplicity of preparation provided high reproducibility. When the same casting solution is used, the maximum deviation in membrane activity is <2%. This, however, is also the precision limit for kinetic investigations. 

Several enzymes have been immobilized in sol-gel matrices effectively and employed in diverse applications. Urease, catalase, and adenylic acid deaminase were first encapsulated in sol-gel matrices [72], The encapsulated urease and catalase retained partial activity but adenylic acid deaminase completely lost its activity. After three decades considerable attention has been paid again towards the bioencapsulation using sol-gel glasses. Braun et al. [73] successfully encapsulated alkaline phosphatase in silica gel, which retained its activity up to 2 months (30% of initial) with improved thermal stability. Further Shtelzer et al. [58] sequestered trypsin within a binary sol-gel-derived composite using TEOS and PEG. Ellerby et al. [74] entrapped other proteins such as cytochrome c and Mb in TEOS sol-gel. Later several proteins such as Mb [8], hemoglobin (Hb) [56], cyt c [55, 75], bacteriorhodopsin (bR) [76], lactate oxidase [77], alkaline phosphatase (AP) [78], GOD [51], HRP [79], urease [80], superoxide dismutase [8], tyrosinase [81], acetylcholinesterase [82], etc. have been immobilized into different sol-gel matrices. Hitherto some reports have described the various aspects of sol-gel entrapped biomolecules such as conformation [50, 60], dynamics [12, 83], accessibility [46], reaction kinetics [50, 54], activity [7, 84], and stability [1, 80],... 

A.M. Hartnett, C.M. Ingersoll, G.A. Baker, and F.V. Bright, Kinetics and thermodynamics of free flavins and the flavin-based redox active site within glucose oxidase dissolved in solution or sequestered within a sol-gel-derived glass. Anal. Chem. 71, 1215-1224 (1999). 

R. Hille and R.F. Anderson, Coupled electron/proton transfer in complex flavoproteins — solvent kinetic isotope effect studies of electron transfer in xanthine oxidase and trimethylamine dehydrogenase. J. Biol. Chem. 276, 31193-31201 (2001). 

Cabanes J, Escribano J, Gandia-Herrero F, Garcia-Carmona F nd Jimenez-Atienzar M. 2007. Partial purification of latent polyphenol oxidase from peach (Prumis persica L. Cv. Catherina). Molecular properties and kinetic characterization of soluble and membrane-bound forms. J Agric Food Chem 55(25) 10446-10451. 

Jimenez-Atienzar M, Cabanes J, Gandia-Herrero F and Garcia-Carmona F. 2004. Kinetic analysis of catechin oxidation by polyphenol oxidase at neutral pH. Biochem Biophys Res Commun 319 902-910. 

Orenes-Pinero E, Garcia-Carmona F and Sanchez-Ferrer A. 2005. A kinetic study of p-cresol oxidation by quince fruit polyphenol oxidase. J Agric Food Chem 53(4) 1196-1200. 

Sojo MM, Nunez-Delicado E, Sanchez-Ferrer A and Garcia-Carmona F. 2000. Oxidation of salsolinol by banana pulp polyphenol oxidase and its kinetic synergism with dopamine. J Agric Food Chem 48(11) 5543-5547. 

CL reaction can be catalyzed by enzymes other than HRP (e.g., microperoxidase and catalase) and by other substances [hemoglobin, cytochrome c, Fe(III), and other metal complexes]. The presence of suitable molecules such as phenols (p-iodophenol), naphthols (l-bromo-2-naphthol), or amines (p-anisidine) increases the light production deriving from the HRP-catalyzed oxidation of luminol and produces glow-type kinetics [6, 7], The use of other enzymes, such as glucose-6-phosphate dehydrogenase [38-41], P-galactosidase [42], and xanthine oxidase [43-46], as CL labels has been reported. 

Many transition metal complexes have been considered as synzymes for superoxide anion dismutation and activity as SOD mimics. The stability and toxicity of any metal complex intended for pharmaceutical application is of paramount concern, and the complex must also be determined to be truly catalytic for superoxide ion dismutation. Because the catalytic activity of SOD1, for instance, is essentially diffusion-controlled with rates of 2 x 1 () M 1 s 1, fast analytic techniques must be used to directly measure the decay of superoxide anion in testing complexes as SOD mimics. One needs to distinguish between the uncatalyzed stoichiometric decay of the superoxide anion (second-order kinetic behavior) and true catalytic SOD dismutation (first-order behavior with [O ] [synzyme] and many turnovers of SOD mimic catalytic behavior). Indirect detection methods such as those in which a steady-state concentration of superoxide anion is generated from a xanthine/xanthine oxidase system will not measure catalytic synzyme behavior but instead will evaluate the potential SOD mimic as a stoichiometric superoxide scavenger. Two methodologies, stopped-flow kinetic analysis and pulse radiolysis, are fast methods that will measure SOD mimic catalytic behavior. These methods are briefly described in reference 11 and in Section 3.7.2 of Chapter 3. 

Recent advances in measuring the kinetics of the various electron-transfer steps in this system have been achieved by use of flash photolysis of ruthenated derivatives of cytochrome c (Ru-Cc) (17-19). In these studies [Ru(bpy)3]2+ is covalently bound to a surface residue at a site that does not interfere with the docking of cytochrome c to cytochrome c oxidase. Solutions are then prepared containing both Ru-Cc and cytochrome c oxidase, and the two proteins associate to form a 1 1 complex. Flash photolysis of the solution leads directly to the excitation of the RuII(bpy)3 site, which then reduces heme c very rapidly. This method thus provides a convenient means to observe the subsequent intracomplex electron transfer from heme c to cytochrome c oxidase and further stages in the process. 

A number of autoxidation reactions exhibit exotic kinetic phenomena under specific experimental conditions. One of the most widely studied systems is the peroxidase-oxidase (PO) oscillator which is the only enzyme reaction showing oscillation in vitro in homogeneous stirred solution. The net reaction is the oxidation of nicotinamide adenine dinucleotide (NADH), a biologically vital coenzyme, by dioxygen in a horseradish peroxidase enzyme (HRP) catalyzed process ... 

Panoutsopoulos GI, Beedham C. Kinetics and specificity of guinea pig liver aldehyde oxidase and bovine milk xanthine oxidase towards substituted benzaldehydes. Acta Biochim Pol 2004 51(3) 649-663. 

FIGURE 5.7. Effect of changing the cosubstrate and the pH on the kinetics of an homogeneous redox enzyme reaction as exemplified by the electrochemical oxidation of glucose by glucose oxidase mediated by one-electron redox cosubstrates, ferricinium methanol ( ), + ferricinium carboxylate ( ), and (dimethylammonio)ferricinium ( ). Variation of the rate constant, k3, with pH. Ionic strength, 0.1 M temperature 25°C. Adapted from Figure 3 in reference 11, with permission from the American Chemical Society. 

Antigen-Antibody Immobilization of Glucose Oxidase. Kinetic Analysis... 

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