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Injections of horseradish peroxidase conjugated with wheat germ agglutinin (WGA-HRP) were made into the cortex of kittens. When cytochrome oxidase histochemistry was performed on sections taken through the injection sites staining of the WGA-HRP deposits occurred, demonstrating that WGA-HRP can cross-react during processing for cytochrome oxidase.
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Tomato (Lycopersicon esculentum Mill) anionic peroxidase was found to catalyze oxidase reactions with NADH, glutathione, dithiothreitol, oxaloacetate, and hydroquinone as substrates with a mean activity 30% that of horseradish peroxidase; this is in contrast to the negligible activity of the tomato enzyme as compared to the horseradish enzyme in catalyzing an indoleacetic acid-oxidase reaction with only Mn(2+) and a phenol as cofactors. Substitution of Ce(3+) for Mn(2+) produced an 18-fold larger response with the tomato enzyme than with the horseradish enzyme, suggesting a significant difference in the autocatalytic indoleacetic acid-oxidase reactions with these two enzymes. In attempting to compare enzyme activities with 2,4-dichlorophenol as a cofactor, it was found that reaction rates increased exponentially with both increasing cofactor concentration and increasing enzyme concentration. While the former response may be analogous to allosteric control of enzyme activity, the latter response is contrary to the principle that reaction rate is proportional to enzyme concentration, and additionally makes any comparison of enzyme activity difficult.
Human adult lung fragments removed from macroscopically undamaged and anthracosis exempted zones of lungs of 20 pneumonectomies made for cancer, were tested for 25 enzymic activities. The location and intensities of these enzymic activities were different in the lung tissue components; The bronchial epithelia contained highly active LDH, MDH, SDH, NADH-TR and NADPH-TR, glucose-6-phosphate dehydrogenase, active hydroxyproline-2-epimerase, alkaline phosphatase. Ca2+-activated ATP-ase, and beta-galactosidase. Bronchial and vascular muscles presented intense activities of LDH, MDH and SDH of alkalinephosphatase, AMP-ase and Ca2+-activated ATP-ase, as well as of beta-galactosidase. The alveolar walls presented high activities of SDH, MDH and LDH, of alkaline and acid phosphatases, of beta-galactosidase and of Tween-40 and 60-esterases, of HEP, cytochrome-oxidase and peroxidase. The free alveolar macrophages were active for LDH, MDH, SDH, NADH-TR and NADPH-TR, G1-6-ph-DH, acid and alkaline phosphatase, cytochrome-oxidase and peroxidase, HEP, AMP-ase and Mg2+-activated ATP-ase, Tween-esterases, naphthol-ASD-acetate esterase, and beta-galactosidase. The endothelia contained high activities of alkaline phosphatase, of AMP-ase and Mg2+-activated ATPase, of LDH, MDH and SDH, and of beta-galactosidase. In bronchial lymphoid nodules it was the LDH, MDH, SDH, cytochrome-oxidase and peroxidase, HEP, alkaline phosphatase and AMP-ase, Tween-60-esterase and beta-galactosidase that were active. The interlobular areas of the lung presented intense activities of SDH, MDH, LDH, HEP and cytochrome-oxidase. The activities of the other tested enzymes were weaker or absent in the adult human lung components, the same as those of aminopeptidases which were present only in some free alveolar macrophages. The discussion of some relationships between these enzymic actitivies and the morphology of the human adult lung tissue asserted that the latter could not be considered as a "normal" tissue but as one overstrained by the components of blood and polluted air.
The H(2)O(2) supply strategy was one of crucial factors for high efficient degradation of pollutants with lignin peroxidase (LiP). In this paper, an attempt was made to couple a H(2)O(2) producing enzymatic reaction to the LiP catalyzed oxidation of dyes. H(2)O(2) needed was generated by glucose oxidase (GOD) and its substrate glucose. The generation rate of H(2)O(2) could be easily controlled by adjusting the pH of the degradation system and the amount of GOD added. Due to the controlled release of H(2)O(2), a sustainable constant activity of LiP was observed. The inhibition of LiP by high level H(2)O(2) supplied externally by a single addition at the beginning of the experiments could be avoided. Degradation of three dyes (xylene cyanol, fuchsine and rhodamine B) with LiP coupled with GOD indicated that the present H(2)O(2) supply strategy was very effective for improvement of the efficiency of the decolourization of dyes.
Polymers and copolymers of horseradish root peroxidase (HRP) and Penicillium funiculosum 46.1 glucose oxidase (GO) have been synthesized and their catalytic properties have been characterized (free and immobilized forms of each enzyme were studied). The cooxidation reaction of phenol and 4-aminoantipyrin (4-AAP), performed in an aqueous medium in the presence of equimolar amounts of GO and HRP, was characterized by effective K(M) and k(cat) of 0.58 mM and 20.9 s(-1) (for phenol), and 14.6 mM and 18.4 s(-1) (glucose), respectively. The catalytic efficiency of polymerization products (PPs) of GO (GO-PPs) depended on the extent of their aggregation. The combinations GO + HRP-PP and HRP + GO-PP, as well as the copolymer HRP*-GO-PP, proved promising as reagents for enzyme-based analytical systems. When adsorbed on aluminum hydroxide gels, GO-PPs exhibited higher catalytic activity than the non-polymeric enzyme. Maximum retention of GO-PP activity on the inorganic carrier was observed in the case of GO-PP copolymers with an activated HRP. Polymerization of HRP in the presence of a zinc hydroxide gel, paralleled by HRP-PP immobilization onto the gel, increased both the activity of the enzyme and its operational stability.
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In the recent time, several in vitro and in vivo studies have shown the inhibitory effect of grapefruit juice on metabolism of xenobiotics catalyzed by liver oxidative enzymes including cytochrome P450 izoenzymes. However, all these experiments were done with a single dose of grapefruit juice. The primary aim of this study was to evaluate if the chronical ingestion of grapefruit juice can cause enzyme activity alteration as well as a single dose. Three groups of male mice were used: the control group, the group which was administered 0.2 mL of grapefruit juice per os 10 days and the group which was administered single dose of 0.5 mL grapefruit juice per os 90 min. before the sacrificing. After the sacrificing of animals, liver was homogenized with appropriate buffer, and the activity of oxidative liver enzymes: xanthine oxidase (XOD), peroxidase (Px), catalase (CAT), lipid peroxidase (LPx), glutathion peroxidase (GSH-Px) and liver glutathion contents (GSH) were detected by standard methods. The results show that the enzyme activity of liver MFO was changed according to a single or multiple grapefruit juice ingestion. The grapefruit juice in a single oral dose significantly decreases the activity of xanthine oxidase, glutathion peroxidase, lipid peroxidase and liver glutathion contents, and has no effect on activity of catalase and peroxidase. The multiple grapefruit ingestion increases the activity of XOD, GSH-Px, LPx, Px and GSH, while the activity of CAT enzyme is unchanged. The chronical and single grapefruit ingestion has no effect on relative liver weight, but the liver protein content is significantly decreased after the multiple oral grapefruit juice ingestion.
A method for determination of picomolar quantities of acetylcholine and choline in solutions and tissue extracts is described. The analytes are injected into a continuous stream of a simple medium flowing through a sequence of enzyme reactors containing acetylcholinesterase, choline oxidase, and peroxidase. Additional reactors with choline oxidase and catalase are used to remove endogenous choline from the tissue extracts in which the content of acetylcholine is to be measured. Reaction products are detected fluorometrically or luminometrically. The limits of sensitivity are about 10 pmol/sample with luminometric and 0.2 pmol/sample with fluorometric detection.
Stable films of dimyristoylphosphatidylcholine and M. tuberculosis catalase-peroxidase (KatG), several peroxidases, myoglobin, and catalase showed reversible FeIII/FeII voltammetry on pyrolytic graphite electrodes and catalytic current for hydrogen peroxide and oxygen. Amperometric responses for these films to H2O2 at 0 V are likely to contain significant contributions from catalytic reduction of oxygen produced during the catalytic cycles. Relative apparent turnover rates at pH 6 based on steady-state currents at 0 V versus SCE in the presence of H2O2 were in the order horseradish peroxidase > cytochrome c peroxidase (CcP) > soybean peroxidase > myoglobin > KatG > catalase. Lower currents for the very efficient peroxide scavengers KatG and catalase may be related to the instability of their compounds I in the presence of H2O2. KatG catalyzed the electrochemical reduction of oxygen more efficiently than catalase and CcP but less efficiently than the other peroxidases. DMPC films incorporating glucose oxidase and peroxidases gave good analytical responses to glucose, demonstrating the feasibility of dual enzyme-lipid films for biosensor fabrication.
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Bifidobacteria, which are obligate anaerobes, were studied to determine the relationship between their sensitivity to oxygen and oxygen metabolism. Among the four species tested, Bifidobacterium infantis, Bifidobacterium breve, and Bifidobacterium longum differed from Bifidobacterium adolescentis in sensitivity to oxygen. The former three species showed marked growth under conditions of partial aeration, whereas the growth of B. adolescentis was suppressed by low concentrations of oxygen. Bifidobacteria express reduced NAD-oxidase and -peroxidase activities, which function in a pathway for two-electron reduction of molecular oxygen, producing hydrogen peroxide and, subsequently, water. Activities of reduced NAD-oxidase and -peroxidase were inversely correlated with their sensitivities to oxygen. Bifidobacterium adolescentis exhibited lowered activities of these two enzymes; the activities were 10 to 20% of those observed with B. infantis, B. breve, and B. longum. These observations are compatible with the hypothesis that reduced NAD-oxidase and reduced NAD-peroxidase in Bifidobacterium species play a role in prevention of oxygen toxicity. Superoxide dismutase activity was also detected in Bifidobacterium species. Superoxide dismutase is probably not involved in detoxification of oxygen, because the activity of this enzyme was extremely low, and the sensitivity to oxygen varied independently of superoxide dismutase activity.
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A colorimetric peroxidase-coupled procedure for determination of creatinine in human serum and urine is described. A 30-s sample pre-treatment with bilirubin oxidase eliminates interference from endogenous bilirubin. The 4-aminoantipyrine-2-hydroxy-3,5-dichlorobenzenesulfonate chromogen system of this method is about fourfold more sensitive than current procedures that involve monitoring NAD(P)H and nearly fivefold more sensitive than the traditional picrate procedures. Incorporation of a sample blank eliminates positive interference from endogenous creatine. Results of the proposed procedure are somewhat lower than those of the common kinetic or equilibrium picrate techniques, as would be expected because of the effects of the well-known interferences in the latter methods.
Cytochemical changes during the early development of maize caryopsis are reported. Changes in the localization of different reserve substances (e.g. polysaccharides, proteins, nucleic acids and lipids) and enzymes (acid phosphatase, esterase, lipase, phosphorylase, succinate dehydrogenase, cytochrome oxidase and peroxidase) have been studied in unfertilized and fertilized ovules. Before pollination very feeble enzyme activity (acid phosphatase, succinate dehydrogenase, cytochrome oxidase and peroxidase) was observed. Reserve substances were present in low amounts before pollination. Pollination stimulated the accumulation of several substances and enzymes in the tip of the nucellus, micropylar zone. Just prior to, during and after fertilization, the cells in the micropylar zone had strong reaction for several enzymes indicating temporary enhancement of metabolic activity in the micropylar zone. The role of antipodals in the storage of reserve food products and nutrition of embryo and early stages of endosperm development is discussed. The pattern of enzymatic changes within the embryo sac reflected the biochemical changes operative during quiescent and active stages. The nucellus of Zea mays contains many enzymes required for hydrolysis of reserved food substances. A role of acid phosphatase in autolysis of nucellar cells, after fertilization is suggested. Post-fertilization increase in the activity of enzymes and accumulation of reserve materials is interpreted as reflecting a presumed increase in the metabolic rate relative to growth and differentiation.
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Lectins conjugated to horseradish peroxidase were used to stain paraffin sections of mouse, rat, and human respiratory tract tissues. An additional method was applied utilizing galactose oxidase to oxidize the C-6 hydroxyl of galactose and N-acetylgalactosamine residues and the resulting aldehyde was visualized with 2% Schiff's reagent. Sections were stained prior to and after removal of sialic acid residues. Oligosaccharides with terminal beta-galactose and alpha-N-acetylgalactosamine residues were found in all serous cells in the mouse trachea but were never seen in human tracheal serous cells. About 5-10% of serous cells in the rat trachea contained terminal beta-galactose, whereas all human tracheal serous cells and the remainder of those in the rat contained oligosaccharides with terminal sialic acid and penultimate beta-galactose residues. Fucose was not detected in tracheal serous cells of any species. Mucous cells in the mouse and rat trachea produced heterogeneous oligosaccharides containing terminal alpha-N-acetylgalactosamine and/or terminal sialic acid residues in various proportions. The structure of oligosaccharides in human tracheal mucous cells varied between individuals and was related to ABO blood group reactivity. The majority of oligosaccharides in type A individuals contained terminal alpha-N-acetylgalactosamine, whereas type AB individuals had approximately equal amounts of terminal alpha-galactose and alpha-N-acetylgalactosamine residues. Mucous cells in the two type O specimens examined contained a large amount of terminal beta-galactose and surprisingly, terminal fucose was not detected in these individuals. These results support biochemical studies showing structural diversity in oligosaccharide chains of respiratory tract secretions and reveal differences in glycoprotein secretion of different cell types.
In this study we used a peroxidase model system (glucose/glucose oxidase and horseradish peroxidase) to investigate the effect of extracellularly generated reactive metabolites of 3,5-Me2-acetaminophen on cell viability and on cellular thiol levels. Incubation of hepatocytes with 3,5-Me2-acetaminophen in the presence of glucose/glucose oxidase and horseradish peroxidase caused a concentration-dependent loss of cell viability. Loss of viability was associated with decreased protein thiol levels. Addition of the reducing agent DTT, but not catalase, during the incubation restored cellular protein thiol levels and arrested the cell killing. Protein thiol depletion occurred selectively to the mitochondrial and microsomal fractions and was specific for a very limited number of protein bands. The data suggest that the oxidative modification of individual protein cysteine residues within the latter two organelle fractions is critically involved in the mechanism of toxicity.