Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We developed a simple, kinetic method for the determination of catalase activity in which i) the enzyme catalyzes the peroxidation of ethanol by hydrogen peroxide to acetaldehyde and water, and ii) the acetaldehyde so formed is rapidly oxidized to acetic acid and NADPH by the addition of an excess of NADP+ and aldehyde dehydrogenase. The rate of NADPH production was monitored at 340 nm in a COBAS centrifugal analyzer. The reaction was linear to 800 U/L or a delta A of 0.020/min. Using human serum pools containing 80 and 460 U/L of peroxidase activity, the within-run coefficients of variation (CV) were 1.9 and 1.3%, respectively. Between-run CV values were 5% for both pools. The reference range for sera from 72 males and 52 females was 23 to 158 U/L (mean + 2 SD) by log normal transformation. The activity in red cells was 600 U/g hemoglobin but did not change the reference range appreciably provided that serum without visible hemolysis was used. Preliminary observations on sera from nine patients with various pancreatic disorders showed a poor correlation between the activities of catalase (peroxidase) and amylase in serum. The reasons for this discrepancy are under investigation.
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PMID:Determination of serum catalase activity on a centrifugal analyzer by an NADP/NADPH coupled enzyme reaction system. 155 Dec 37

The conversion of pheromonal aldehydes to carboxylic acids in vitro in tissue extracts of Heliothis virescens is catalyzed by both aldehyde dehydrogenase and aldehyde oxidase enzymes. The aldehyde-oxidizing activity in antennae, heads, legs, and hemolymph from male and female moths was examined by radiochromatographic and spectroscopic assays. First, the enzymatic activity was measured in the presence or absence of added NAD+ using either (Z)-9-tetradecenal or (Z)-11-hexadecenal as tritiated substrate. Second, substrate specificity was determined spectroscopically by (i) indirect measurement of the AO-released hydrogen peroxide through the coupled AO-horseradish peroxidase reaction and by (ii) direct measurement of the ALDH-produced NADH. Both aldehyde-oxidizing activities were associated with soluble enzymes in the antennal extracts, and these enzymes degraded pheromone and nonpheromonal aldehydes. Both AO and ALDH activities were present in male and female tissues. AO activity was exhibited primarily in the antennal extracts and to a lesser degree in the leg extracts. Moreover, ALDH activity was distributed in the antenna, head, and leg extracts. A vinyl ketone analog of (Z)-11-hexadecenal preferentially inhibited the ALDH activity over the AO activity.
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PMID:Aldehyde-oxidizing enzymes in an adult moth: in vitro study of aldehyde metabolism in Heliothis virescens. 232 97

The 9,10-mono-ozonide of methyl linoleate was shown to be a substrate for rat hepatic cytosolic, rat lung cytosolic and rat hepatic microsomal glutathione S-transferases (GST). The activities of lung cytosol and liver microsomes with methyl linoleate ozonide (MLO) were found to be high relative to the activity demonstrated by liver cytosol, as compared with their respective activities towards 1-chloro-2,4-dinitrobenzene (CDNB). Only a slight catalytic activity towards the ozonide was noticed for rat lung microsomes. Isoenzyme 2-2 exhibited the highest specific activity (208 nmol/min/mg) when isoenzymes 1-1, 1-2, 2-2, 3-3, 3-4, 4-4 and 7-7 were compared. This isoenzyme accounts for approx. 25% of cytosolic GST protein in rat lung, while in rat liver it represents approx. 9%. This may partly explain the high activity towards the ozonide noticed for rat lung cytosol. No stable conjugates were formed as products of the reaction of MLO with glutathione; although two glutathione-conjugates were noticed on TLC, they were only formed as intermediate compounds. Coupling of an aldehyde dehydrogenase assay or a glutathione reductase assay to the GST-catalyzed conjugation, demonstrated that oxidized glutathione and aldehydes are formed as the major products in the reaction. To further confirm the formation of aldehydes, the products of the GST-catalyzed reaction were incubated with 2,4-dinitrophenylhydrazine, which resulted in hydrazone formation. In conclusion, the activity of the GST towards the ozonide of methyl linoleate is similar to their peroxidase activity with lipid hydroperoxides as substrates.
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PMID:Methyl linoleate ozonide as a substrate for rat glutathione S-transferases: reaction pathway and isoenzyme selectivity. 270 6

We have previously reported the detection of a 37 kD liver protein-acetaldehyde adduct in rats fed alcohol chronically with the AIN'76 diet. It was surprising that only one liver protein-acetaldehyde adduct was found. In this report, we have tried to detect additional protein-acetaldehyde adducts by electroimmunotransblot with rabbit anti-hemocyanin-acetaldehyde adduct IgG and to further characterize the 37 kD liver protein-acetaldehyde adduct. Sensitivity of electroimmunotransblot increased 10- to 20-fold when alkaline phosphatase-linked antibody was used in place of horseradish peroxidase, but only one protein-acetaldehyde adduct band was detected in liver. Feeding rats the Lieber-DeCarli alcohol diet also did not produce more protein-acetaldehyde adduct bands in electroimmunotransblot. Addition of cyanamide, an aldehyde dehydrogenase inhibitor, to the AIN'76 alcohol diet greatly increased the intensity of the 37-kD protein-acetaldehyde adduct band on electroimmunotransblot but did not produce other bands. The 37 kD protein-acetaldehyde adduct decayed in vivo with a half-life of 4 days when alcohol was removed from the diet. The 37 kD protein-acetaldehyde adduct in liver is cytosolic. Its interaction with anti-hemocyanin-acetaldehyde adduct IgG was blocked by polylysine-acetaldehyde adduct and polytyrosine-acetaldehyde adduct. It could be removed by immunosorption with anti-hemocyanin-acetaldehyde adduct IgG-bound immunoresin. When immunoblotted with anti-alcohol dehydrogenase and anti-aldehyde dehydrogenase antibodies, the alcohol dehydrogenase and aldehyde dehydrogenase bands in liver of alcohol-fed rats showed identical intensities before and after immunosorption.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Further studies on the 37 kD liver protein-acetaldehyde adduct that forms in vivo during chronic alcohol ingestion. 280 59

We describe the problems encountered with the adaptation of two enzymatic assays for uric acid to a centrifugal analyser. A method employing the uricase/catalase/aldehyde dehydrogenase enzyme system sometimes suffered from interference due to light-scattering species in samples and reagents. The second method employing the uricase/peroxidase system gave results that were lower than the comparison method.
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PMID:Problems associated with the measurement of uric acid using two enzyme-mediated reaction systems. 650 11

A library derived from mRNA in the bacterial light organ of the squid, Euprymna scolopes, contained an unexpectedly high proportion of cDNAs that encode proteins with approximately 30% similarity to a family of mammalian peroxidases (PO) including myelo-PO, eosinophil PO, and thyroid PO (donor:hydrogen-peroxide oxidoreductase; EC 1.11.1.7). Two nearly full-length cDNAs were determined to encode putative PO of nearly 93 kDa each that are 97% identical in amino acid sequence to each other. Each contains four potential glycosylation sites, and His416, believed to be within the active site of the human PO, is conserved in the putative PO from the squid light organ. The mRNAs for the putative squid PO were approximately 250 times more abundant in the tissue housing the bacterial symbiont than in the ocular lens or mantle and were undetectable in the light organ lens. By analogy with the bacteriocidal function of PO in mammalian neutrophils, the putative squid PO may be important for modulating or limiting the population of bacteria within the light organ. The possibility that the squid light organ contains a high concentration of PO raises the possibility that the light organ lens is under oxidative stress, providing a possible rationale for the recruitment of its aldehyde dehydrogenase-like crystallin.
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PMID:Abundant mRNAs in the squid light organ encode proteins with a high similarity to mammalian peroxidases. 822 67

Immunocytochemical study of regional and cellular distribution of mitochondrial high-affinity aldehyde dehydrogenase (MA AlDH) in the rat CNS was performed by streptavidin-biotin-peroxidase method. Specific immunoreactivity of diverse intensity was found in most structures of brain and spinal cord regions mainly in neuronal and gliocyte cytoplasm and to a smaller extent, in their processes, terminations (neuropile conducting tracts, white matter) and blood vessels: immune reaction intensity of perikarya of different type neurons exceeds those of neuropile 1.8-3.3 times. MA AlDH positive neurons were observed in all the cerebral regions, with the most intensive specific staining in inferior olives and hippocamp pyramidal layer (0.500-0.520 optical density units) and the minimal in nucleus rubrum and substantia nigra (0.260-0.290 units). In both cases MA AlDH immunoreactive neurons made only part (from 40 to 88) of morphologically identified (thianine-positive) neurons. Comparative analysis of histochemical preparations and the cytophotometric results revealed significant diversities in topographic distribution of MA AlDG and general AlDG activity in the cerebrum. The data obtained assist in elucidation the spatial organization of alcohol and aldehyde metabolism in CNS and in comprehension the reasons of different sensitivity of brain structures to alcohol.
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PMID:[Regional and cellular distribution of mitochondrial high-affinity aldehyde dehydrogenase in the rat brain (an immunocytochemical study)]. 871 39

S-Methyl N,N-diethylthiolcarbamate sulfoxide (DETC-MeSO) and sulfone (DETC-MeSO2) both inhibit rat liver low Km aldehyde dehydrogenase (ALDH2) in vitro and in vivo (Nagendra et al., Biochem Pharmacol 47: 1465-1467, 1994). DETC-MeSO has been shown to be a metabolite of disulfiram, but DETC-MeSO2 has not. Studies were carried out to further investigate the inhibition of ALDH2 by DETC-MeSO and DETC-MeSO2. In an in vitro system containing hydrogen peroxide and horseradish peroxidase, the rate of DETC-MeSO oxidation corresponded to the rate of DETC-MeSO2 formation. Carbamoylation of GSH by both DETC-MeSO and DETC-MeSO2 was observed in a rat liver S9 fraction. Carbamoylation of GSH was not observed in the presence of N-methylmaleimide. In in vitro studies, DETC-MeSO and DETC-MeSO2 were equipotent ALDH2 inhibitors when solubilized mitochondria were used, but DETC-MeSO was approximately four times more potent than DETC-MeSO2 in intact mitochondria. In studies with rats, the dose (i.p. or oral) required to inhibit 50% ALDH2 (ED50) was 3.5 mg/kg for DETC-MeSO and approximately 35 mg/kg for DETC-MeSO2, approximately a 10-fold difference. Furthermore, maximum ALDH2 inhibition occurred 1 hr after DET(-MeSO administration, whereas maximal ALDH2 inhibition occurred 8 hr after DETC-MeSO2 dosing. DETC-MeSO is, therefore, not only a more potent ALDH2 inhibitor than DETC-MeSO2 in vivo, but also in vitro when intact mitochondria are utilized. The in vitro results thus support the in vivo findings. Since oxidation of DETC-MeSO can occur both enzymatically and non-enzymatically, it is possible that DETC-MeSO2 is formed in vivo. DETC-MeSO2, however, is not as effective as DETC-MeSO in inhibiting ALDH2, probably because it has difficulty penetrating the mitochondrial membrane. Thus, even if DETC-MeSO2 is formed in vivo from DETC-MeSO, it is the metabolite DETC-MeSO that is most likely responsible for the inhibition of ALDH2 after disulfiram administration.
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PMID:Glutathione carbamoylation with S-methyl N,N-diethylthiolcarbamate sulfoxide and sulfone. Mitochondrial low Km aldehyde dehydrogenase inhibition and implications for its alcohol-deterrent action. 958 46

Genetic polymorphisms may modify the effects of environmental risk factors on cancer occurrence. We have recently launched a comprehensive epidemiologic project, HERPACC II (Hospital-based Epidemiologic Research Program at Aichi Cancer Center II), including both lifestyle and polymorphism data, following HERPACC-I which solely concentrated on lifestyle data. As of April 2001, about 3000 samples of DNA are being stored to conduct case-control studies. Genotyping of 46 polymorphisms has been conducted at the laboratory of the Division of Epidemiology and Prevention. Twelve case-control studies and two papers on a new PCR method, PCR-CTPP (polymerase chain reaction with confronting two-pair primers), have been accepted for publication. Significant findings in Japanese were found for 1) gene-environment interaction for esophageal cancer between heavy drinking and aldehyde dehydrogenase 2 (ALDH2), 2) malignant lymphoma risk with methylenetetrahydrofalate reductase (MTHFR) and methionine synthase (MS), 3) interactions between smoking and two polymorphisms, interleukin 1B (IL-1B) and myeloperoxidase (MPO) for Helicobacter pylori infection, and 4) smoking habits with dopamine receptor D2 (DRD2) and IL-1B. Further studies on interactions with polymorphisms will continue to be conducted for Japanese, using larger sizes of samples.
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PMID:Gene-environment Interactions and Polymorphism Studies of Cancer Risk in the Hospital-based Epidemiologic Research Program at Aichi Cancer Center II (HERPACC-II). 1271 40

A proteomic differential display technique was utilized to study cellular responses of Phanerochaete chrysosporium exposed to vanillin, one of the key intermediates found during lignin biodegradation. Intracellular proteins were resolved by 2-DE and target protein spots were identified using MALDI-MS after in-gel tryptic digestions. Upon addition of vanillin to P. chrysosporium, up-regulation of homogentisate 1,2-dioxygenase, 1,4-benzoquinone reductases, aldehyde dehydrogenase, and aryl-alcohol dehydrogenase, which seem to play roles in vanillin metabolism, was observed. Furthermore, enzymes involved in glycolysis, the tricarboxylic acid cycle, the pentose-phosphate cycle, and heme biosynthesis were also activated. Up-regulation of extracellular peroxidase was also observed. One of the most unique phenomena against exogenous vanillin was a switch from the glyoxylate cycle to the tricarboxylic acid cycle, where a drastic increase in isocitrate dehydrogenase activity was observed. The exogenous addition of other aromatic compounds also caused an increase in its activity, which in turn triggered NAD(P)H production via the action of dehydrogenases in the tricarboxylic acid cycle, heme biosynthesis via the action of aminolevulinic acid synthase on succinyl-CoA, and energy production via activation of the mitochondrial electron transfer system. These metabolic shifts seem to be required for activating a metabolic system for aromatic compounds.
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PMID:Metabolic regulation at the tricarboxylic acid and glyoxylate cycles of the lignin-degrading basidiomycete Phanerochaete chrysosporium against exogenous addition of vanillin. 1621 26


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