Oxidase enzymes process

Compared with ketoreductases, the synthetic application of alcohol oxidases has been less explored. However, selective oxidation of primary alcohols to aldehydes is superior to the chemical methods in terms of conversion yields, selectivity, and environmental friendliness of reaction conditions. In addition, coupling of alcohol oxidase with other enzymes provides a tremendous opportunity to develop multi-enzyme processes for the production of complex molecules. Therefore, a growing impact of alcohol oxidases on synthetic organic chemistry is expected in the coming years. 

Many natural products are produced by the coupling of two or more phenolic systems, in a process readily rationalized by means of radical reactions. The reactions can be brought about by oxidase enzymes,... 

Although molybdenum and tungsten enzymes carry the name of a single substrate, they are often not as selective as this nomenclature suggests. Many of the enzymes process more than one substrate, both in vivo and in vitro. Several enzymes can function as both oxidases and reductases, for example, xanthine oxidases not only oxidize purines but can deoxygenate amine N-oxides [82]. There are also sets of enzymes that catalyze the same reaction but in opposite directions. These enzymes include aldehyde and formate oxidases/carboxylic acid reductase [31,75] and nitrate reductase/nitrite oxidase [83-87]. These complementary enzymes have considerable sequence homology, and the direction of the preferred catalytic reaction depends on the electrochemical reduction potentials of the redox partners that have evolved to couple the reactions to cellular redox systems and metabolic requirements. 

Aryl hydrocarbon hydroxylase (AHH) is a complex mixed function oxidase enzyme which converts polycyclic aromatic hydrocarbons such as DMBA to more hydrophilic and readily excretable products. During this process metabolites that are more carcinogenic than the parent compound can be produced. The distribution of MFO enzymes, their activity, and the balance between conversion of procarcinogens to active carcinogens and their detoxification is probably a... 

Synthesis Histamine is an amine formed by the decarboxylation of the amino acid histidine (Figure 40.3). This process occurs primarily in the mast cells, basophils, and in the lungs, skin, and gastrointestinal mucosa—the same tissues in which histamine is stored. In mast cells, histamine is stored in granules as an inactive complex composed of histamine and the polysulfated anion, heparin, along with an anionic protein. If histamine is not stored, it is rapidly inactivated by amine oxidase enzymes. 

Glucose and lactate were simultaneously monitored by Wei Min et al. [191] during the fermentation of Lactococcus lactis. They made use of a microdialysis probe connected to a dual flow-through cell in which two amperometric biosensors were located. The biosensors were based on the co-immobilization of the respective oxidase enzymes together with HRP in a carbon paste matrix. Both analytes were monitored on-hne for about 14 h in a very complex aqueous two-phase fermentation process, and the results were in good agreement with independent ofiF-line HPLC measurements. 

The main advantage of the proposed wine analysis is its selectivity because only primary amines can be detected using this method. Also, byproducts do not interfere with phenols or thiols. The quality of the wine and its organoleptic characteristics are well defined considering the effects of the malolactic fermentation process. The electrometric methods assure reliable results for the 1-malic and 1-lactic acids assay. The biosensors construction for 1-malic and 1-lactic acids assay in wine are based on malate dehydrogenase and lactate oxidase enzymes.117 The reproducibility of the results as well as the selectivity make it reliable for establishing the quality of the wine. 

A. The cyanide ion forms a reversible complex with the respiratory cytochrome oxidase enzyme system, an enzyme system essential for oxidative processes within cells. This results in impairment of cellular oxygen utilization. The central nervous system, particularly the respiratory center, is especially susceptible to this effect and respiratory failure is the usual cause of death. 

In recent experiments mass spectrography has been used to identify 3-(2-hydroxy-4-chlorophenyl)-1,1-dimethylurea and 3-(2-hydroxy-4-chlorophenyl)-1 -methylurea in bean leaves as metabolites of monuron (Lee et al., 1973). This is, in the case of urea herbicides, experimental proof of the hydroxylating (oxidative) detoxication process, performed together with N-dealkylation by the microsomal oxidase enzyme system. 

Ovazyme. [Finnsugar Bioprods.] Glucose oxidase enzyme for food processing. 

Both hydrogen cyanide, HCN, and cyanide salts, are rapidly acting poisons. A dose of only 60-90 mg is sufficient to kill a human. Cyanide bonds to Fe in an iron-containing ferrocytochrome oxidase enzyme, preventing its reduction to Fe " " in the oxidative phosphorylation process, by which the body utilizes oxygen. The cmcial enzyme is inhibited because ferrocytochrome oxidase, which is required to react with O2, is not formed and utilization of oxygen in cells is prevented so that metabolic processes cease. 

Oxidations. Most oxidative processes take place in liver microsomes and are catalysed by mono-oxygenase enzymes known as mixed-function oxidases. These processes require reduced nicotinamide-adenine dinucleotide phosphate, molecular oxygen and a complex of enzymes in the endoplas-matic reticulum. The terminal oxidizing enzyme is cytochrome P450, a hemoprotein. The notation P450 refers to the ability of the reduced (ferrous) form of the hemoprotein to react with carbon monoxide, yielding a complex with absorption peak at 450 nm. For each molecule... 

Heme A is an obligatory cofactor in all eukaryotic and most bacterial cytochrome c oxidase enzymes (CcO). Because of its importance to CcO and aerobic metabolism, considerable effort has recently been invested in understanding the mechanism and regulation of heme A biosynthesis. The activity of heme A synthase is strictly dependent on O2, and yet there is no incorporation of O2 into the products. Heme A synthase is now known to utilize a unique electron-transfer mechanism when oxidizing heme O to heme A. Interestingly, the heme A biosynthetic pathway is regulated at least partly via a heme-dependent process in which heme A synthase is positively regulated by intracellular heme levels via Hapl. 

The purpose of the study by Quoc et al (2006) was to develop a process to enable quick inactivation of the polyphenol oxidase enzyme, which is present in cloudy or unclarified apple juice. This enzyme is responsible for enzymatic... 

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