Showing papers on "Aldehyde dehydrogenase published in 1990"
TL;DR: It is found that hematopoietic progenitor cells express the highest level of ALDH, while lymphocytes express the lowest level, in the marrow subpopulations.
294 citations
TL;DR: The differences in ethanol and acetaldehyde metabolizing activities of allelic enzyme forms may be responsible in part for the large variation in the alcohol metabolism rate in humans.
Abstract: The enzymes mainly responsible for ethanol degradation in humans are liver alcohol dehydrogenases (ADH) and aldehyde dehydrogenases (ALDH). Polymorphisms occur in both enzymes, with marked differences in the steady-state kinetic constants. The Km-values for ethanol of ADH isoenzymes relevant for alcohol degradation range from 49 microM to 36 microM, and the Vmax-values from 0.6 to 10 U/mg. Expression of an inactive form of the ALDH2 isoenzyme, the so-called Oriental variant, results in impaired acetaldehyde metabolizing capacity. The differences in ethanol and acetaldehyde metabolizing activities of allelic enzyme forms may be responsible in part for the large variation in the alcohol metabolism rate in humans. Interindividual differences in the isoenzyme pattern may contribute to the genetically determined predisposition for excessive alcohol intake.
161 citations
TL;DR: Protein yields from enzyme purification, as well as electrophoretic analyses of crude and purified enzyme preparations, demonstrated that this enzyme is the major soluble protein in bovine cornea, and constitutes around 0.5% wet weight of tissue.
133 citations
TL;DR: Kinetic data suggest a ping-pong mechanism for the reaction, and ALDH was more stable in Tris buffer than in phosphate buffer, and the ratio of NAD(H)/NADP(H)-linked activities increased with decreasing pH.
Abstract: Acetaldehyde and butyraldehyde are substrates for alcohol dehydrogenase in the production of ethanol and 1-butanol by solvent-producing clostridia. A coenzyme A (CoA)-acylating aldehyde dehydrogenase (ALDH), which also converts acyl-CoA to aldehyde and CoA, has been purified under anaerobic conditions from Clostridium beijerinckii NRRL B592. The ALDH showed a native molecular weight (Mr) of 100,000 and a subunit Mr of 55,000, suggesting that ALDH is dimeric. Purified ALDH contained no alcohol dehydrogenase activity. Activities measured with acetaldehyde and butyraldehyde as alternative substrates were copurified, indicating that the same ALDH can catalyze the formation of both aldehydes for ethanol and butanol production. Based on the Km and Vmax values for acetyl-CoA and butyryl-CoA, ALDH was more effective for the production of butyraldehyde than for acetaldehyde. ALDH could use either NAD(H) or NADP(H) as the coenzyme, but the Km for NAD(H) was much lower than that for NADP(H). Kinetic data suggest a ping-pong mechanism for the reaction. ALDH was more stable in Tris buffer than in phosphate buffer. The apparent optimum pH was between 6.5 and 7 for the forward reaction (the physiological direction; aldehyde forming), and it was 9.5 or higher for the reverse reaction (acyl-CoA forming). The ratio of NAD(H)/NADP(H)-linked activities increased with decreasing pH. ALDH was O2 sensitive, but it could be protected against O2 inactivation by dithiothreitol. The O2-inactivated enzyme could be reactivated by incubating the enzyme with CoA in the presence or absence of dithiothreitol prior to assay.
87 citations
Journal Article•
TL;DR: Of all the aldehyde dehydrogenases examined, A HD-2 and AHD-8 were estimated to be the most efficient catalysts of aldophosphamide oxidation, thus, these enzymes would seem most likely to be operative when tumor cells acquire alde Hyde dehydrogenase-mediated cycloph phosphamide resistance.
Abstract: Aldophosphamide, the penultimate cytotoxic metabolite of cyclophosphamide, can be detoxified by an oxidation reaction catalyzed by certain aldehyde dehydrogenases. The selective toxicity of cyclophosphamide is due, at least in part, to a greater expression of the relevant aldehyde dehydrogenase activity in normal cells relative to that expressed in certain tumor cells. Not known at the onset of this investigation was which of the several known mouse aldehyde dehydrogenases catalyze this reaction. Twelve enzymes that catalyze the NAD(P)-linked oxidation of aldophosphamide, acetaldehyde, benzaldehyde, and/or octanal were chromatographically resolved from mouse liver. Four of these appear to be novel; four others were determined to be betaine aldehyde dehydrogenase, succinic semialdehyde dehydrogenase, glutamic γ-semialdehyde dehydrogenase, and xanthine oxidase (dehydrogenase). An additional aldehyde dehydrogenase, namely AHD-4, was semipurified from stomach. The stomach enzyme and nine of the hepatic enzymes catalyze the oxidation of aldophosphamide. Km values for these reactions range from 16 µm to 2.5 mm. The relevant aldehyde dehydrogenase of major importance varies with the tissue. In the liver, the major cytosolic aldehyde dehydrogenase, namely AHD-2, accounts for >60% of total hepatic aldehyde dehydrogenase-catalyzed aldophosphamide (160 µm) detoxification. Succinic semialdehyde dehydrogenase (AHD-12) and three of the novel hepatic aldehyde dehydrogenases, namely AHD-8, AHD-10, and AHD-13, also contribute significantly to total hepatic aldehyde dehydrogenase-catalyzed aldophosphamide detoxification. In the stomach, AHD-4 and AHD-8 account for approximately 86% of total aldehyde dehydrogenasecatalyzed aldophosphamide (160 µm) detoxification. AHD-2 was not found in this tissue. Of all the aldehyde dehydrogenases examined, AHD-2 and AHD-8 were estimated to be the most efficient catalysts of aldophosphamide oxidation. Thus, these enzymes would seem most likely to be operative when tumor cells acquire aldehyde dehydrogenase-mediated cyclophosphamide resistance.
75 citations
TL;DR: Hepatic malondialdehyde concentrations were significantly increased in iron‐loaded livers, and mitochondrial respiratory control ratios using glutamate as a substrate were decreased by 47% largely owing to reductions in state 3 respiration.
64 citations
TL;DR: The distribution of carboxylesterase, aldehyde dehydrogenase, cytochromes P-450, epoxide hydrolase, and glutathione S-transferases within the nasal mucosa is reviewed in the context of their contribution to xenobiotic metabolism.
Abstract: An increasing number of chemicals have been identified as being toxic to the nasal mucosa of rats. While many chemicals exert their effects only after inhalation exposure, others are toxic following systemic administration, suggesting that factors other than direct deposition on the nasal mucosa may be important in mechanisms of nasal toxicity. The mucosal lining of the nasal cavity consists of a heterogeneous population of ciliated and nonciliated cells, secretory cells, sensory cells, and glandular and other cell types. For chemicals that are metabolized in the nasal mucosa, the balance between metabolic activation and detoxication within a cell type may be a key factor in determining whether that cell type will be a target for toxicity. Recent research in the area of xenobiotic metabolism in nasal mucosa has demonstrated the presence of many enzymes previously described in other tissues. In particular, carboxylesterase, aldehyde dehydrogenase, cytochromes P-450, epoxide hydrolase, and glutathione S-transferases have been localized by histochemical techniques. The distribution of these enzymes appears to be cell-type-specific and the presence of the enzyme may predispose particular cell types to enhanced susceptibility or resistance to chemical-induced injury. This paper reviews the distribution of these enzymes within the nasal mucosa in the context of their contribution to xenobiotic metabolism. The localization of the enzymes by histochemical techniques has provided important information on the potential mechanism of action of esters, aldehydes, and cytochrome P-450 substrates known to injure the nasal mucosa.
63 citations
TL;DR: Taking together with the finding that the NAD(+)-dependent activity is severalfold higher than the NADPH-dependent one, the dehydrogenase may be important in the oxidation of 20-OH-LTB4 to 20-carboxy-L TB4, which is supported by the finding of the reversal of carbon monoxide inhibition by 450 nm light and by competitive inhibition studies.
36 citations
TL;DR: Using the polymerase chain reaction to amplify genomic DNA from hair roots, it is determined that individuals from this population previously reported to lack aldehyde dehydrogenase activity do not show the presence of the inactive (ALDH2(2) allele frequently found in Orientals.
Abstract: Using the polymerase chain reaction to amplify genomic DNA from hair roots, we have examined the mitochondrial aldehyde dehydrogenase (ALDH2) genotypes of 28 individuals from the South American Mapuche Indians. We have determined that individuals from this population previously reported to lack (ALDH2) activity do not show the presence of the inactive (ALDH2(2] allele frequently found in Orientals.
32 citations
TL;DR: DETC-Me is proposed to be a metabolite of disulfiram, and may be the immediate precursor of the chemical species responsible for L Km ALDH inhibition.
32 citations
TL;DR: The N-terminal signal peptide had only 21 amino acids but showed high sequence identity to the signal sequences of human and rat enzymes, which have 17 and 19 amino acids, respectively, and had general characteristic features of typical mitochondrial signal peptides.
TL;DR: Affinity labelling of aldehyde dehydrogenase with vinyl ketones may prove to be of general utility in biochemical studies of these enzymes.
Abstract: A major component of the sex pheromone from the tobacco budworm moth Heliothis virescens is a C16 straight-chain aldehyde with a single unsaturation at the eleventh position. The sex pheromones are inactivated when metabolized to their corresponding acids by insect aldehyde dehydrogenase. During this investigation it was demonstrated that the C16 aldehyde is a good substrate for human aldehyde dehydrogenase (EC 1.2.1.3) isoenzymes E1 and E2 with Km and Kcat. values at pH 7.0 of 2 microM and 0.4 mumol of NADH/min per mg and of 0.6 microM and 0.24 mumol of NADH/min per mg respectively. A vinyl ketone analogue of the pheromone inhibited insect pheromone metabolism; it also inactivated human aldehyde dehydrogenase. Total inactivation of both isoenzymes was achieved at stoichiometric (equal or less than the subunit number) concentrations of vinyl ketone, incorporating 2.1-2.6 molecules/molecule of enzyme. Substrate protection was observed in the presence of the parent aldehyde and 5′-AMP. Peptide maps of tryptic digests of the E2 isoenzyme modified with 3H-labelled vinyl ketone showed that incorporation occurred into a single peptide peak. The labelled peptide of E2 isoenzyme was further purified on h.p.l.c. and sequenced. The label was incorporated into cysteine-302 in the primary structure of E2 isoenzyme, thus indicating that cysteine-302 is located in the aldehyde substrate area of the active site of aldehyde dehydrogenase. Affinity labelling of aldehyde dehydrogenase with vinyl ketones may prove to be of general utility in biochemical studies of these enzymes.
TL;DR: Kinetic studies have indicated that acetaldehyde derived from ethanol oxidation, medium chain length aliphatic aldehydes derived from membrane lipid peroxidation and perhaps some aldeHydes generated from neurotransmitter metabolism are potential physiological substrates for one or more ALDH forms.
Abstract: Aldehyde dehydrogenases (E. C. 1.2.1.3, ALDH) exist in multiple molecular forms which differ in their physical and/or their functional properties (Weiner, 1979). Aldehyde dehydrogenase has been identified in virtually every organism and tissue examined. Distinct ALDHs have been identified in the mitochondrial, microsomal and cytosolic compartments of the cell (Tottmar et al., 1973; Greenfield and Pietruszko, 1977; Lindahl and Evces, 1984). Some forms are constitutive, some inducible (Deitrich, 1971; Deitrich et al., 1977). Tetrameric and dimeric functional forms are known. Some forms display broad substrate specificity, oxidizing a variety of aliphatic and aromatic aldehydes. Other forms possess much narrower substrate preferences, utilizing small aliphatic aldehydes. Kinetic studies have indicated that acetaldehyde derived from ethanol oxidation, medium chain length aliphatic aldehydes derived from membrane lipid peroxidation and perhaps some aldehydes generated from neurotransmitter metabolism are potential physiological substrates for one or more ALDH forms (Tank et al., 1981; Esterbauer, 1982; Weiner, 1982; Mitchell and Petersen, 1989). While all aldehyde dehydrogenases likely use NAD+ as coenzyme in vivo, some forms can utilize NADP+ in vitro.
TL;DR: The data suggest a lack of relationship between hepatic ethanol-metabolizing activities and the in vivo ethanol elimination rate, and that human liver showed higher alcohol dehydrogenase activity and higher low Km aldehyde dehydrogenases activity than rat liver.
TL;DR: Both aldehyde-oxidizing activities were associated with soluble enzymes in the antennal extracts, and these enzymes degraded pheromone and nonpheromonal aldehydes.
TL;DR: Polymorphism is also to be considered in detoxication and/or target organ metabolism (as collagen polymorphism in alcoholic cirrhosis) and in the future, other polymorphisms in alcohol metabolism may be described.
Abstract: In alcohol toxicity, a lot of data point to genetic factors associated with environmental factors. These genetic factors can intervene at different levels : genetic variability in the distribution of polymorphic alcohol and aldehyde dehydrogenase isozymes (Bosron, et al., 1988) could play a role in determining individual difference in ethanol metabolism and toxicity. In the future, other polymorphisms in alcohol metabolism may be described. Polymorphism is also to be considered in detoxication and/or target organ metabolism (as collagen polymorphism in alcoholic cirrhosis)(Weiner, et al., 1988).
TL;DR: A nucleophilic group in the active site of aldehyde dehydrogenase was acylated with the chromophoric alde Hyde trans-4-(N,N-dimethylamino)cinnamaldehyde (DACA), and the peptide associated with the Chromophoric group was isolated and shown to be Gln-Ala-Phe-Gln-Ile-Gly-Ser-Pro-Trp-Arg.
Abstract: A nucleophilic group in the active site of aldehyde dehydrogenase, which covalently binds the aldehyde moiety during the enzyme-catalyzed oxidation of aldehydes to acids, was acylated with the chromophoric aldehyde trans-4-(N,N-dimethylamino)cinnamaldehyde (DACA). Acyl-enzyme trapped by precipitation with perchloric acid was digested with trypsin, and the peptide associated with the chromophoric group was isolated and shown to be Gln-Ala-Phe-Gln-Ile-Gly-Ser-Pro-Trp-Arg. After redigestion with thermolysin, the chromophore was associated with the C-terminal hexaresidue part. If the chromophore is attached to this peptide, serine would be expected to bind the aldehyde and lead to the required acylated derivative. Differential labeling experiments were performed in which all free thiol groups on the acylated enzyme were blocked by carboxymethylation. The acyl chromophore was then removed by controlled hydrolysis and the protein reacted with [14C]iodoacetamide. No 14C-labeled tryptic peptides were isolated, suggesting that the sulfur of a cysteine cannot be the acylated residue in the precipitated acyl-enzyme.
TL;DR: The rate at which aldehyde dehydrogenase-catalyzed biotransformation occurs in various tissues can be of major importance with regard to the ultimate therapeutic efficacy of drugs and other xenobiotics that are aldeHydes or that give rise to aldehydes.
Abstract: The rate at which aldehyde dehydrogenase-catalyzed biotransformation occurs in various tissues can be of major importance with regard to the ultimate therapeutic efficacy of drugs and other xenobiotics that are aldehydes or that give rise to aldehydes (Sladek, et al., 1989). Examples of such agents are cyclophosphamide and the retinoids, retinol and beta-carotene.
TL;DR: Labeled vinyl ketones are novel tools for the identification of molecular subunits of ALDH enzymes in the fluorescence autoradiograms of sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated proteins of the antenna, head, and leg tissues.
TL;DR: It is shown that liver alcohol dehydrogenase present in human mainly corresponded to class I and in rat to class ADH-3 which differed in a number of parameters, and caution must be paid when extrapolating to human subjects the data on ethanol metabolism obtained with rats.
Abstract: 1. On the basis of kinetic properties and sensitivity to pyrazole inhibition, it is shown that liver alcohol dehydrogenase present in human mainly corresponded to class I and in rat to class ADH-3 which differed in a number of parameters. 2. Two different aldehyde dehydrogenase (ALDH) isoenzymes were detected in both human and rat liver. The human isoenzymes corresponded to the ALDH-I and ALDH-II type. 3. In the rat, one isoenzyme had low K m and showed similar activity than in human liver but differed in their sensitivity to both disulfiran and nitrofazole inhibition whereas the other presented high K m and showed greater activity than the human one. 4. Caution must be therefore paid when extrapolating to human subjects the data on ethanol metabolism obtained with rats.
TL;DR: The results suggest that long-lasting biochemical and behavioral effects of alcohol may occur in the offspring starting at the earliest stage of development.
Abstract: The effect of maternal alcohol exposure before mating was investigated in the offspring over a period of 6 months concerning some specific aspects of energy metabolism in the brain and the liver. The following biochemical parameters were analyzed: superoxide dismutase (involved in elimination of free radicals produced during ethanol oxidation), enolase isoenzymes (markers of nerve cell maturation), and alcohol and aldehyde dehydrogenase (the main alcohol degradating enzymes). These enzymatic activities were measured at their subcellular level. In these animals never directly exposed to alcohol, superoxide dismutase activity was decreased mainly in the liver cytosol. Only the nonneuronal form of enolase activity was modified. Alcohol dehydrogenase was decreased in the liver as well as in the brain. Aldehyde dehydrogenase was also decreased in the liver and in the brain, mainly in the mitochondria. Behavioral observations showed decreased emotional reactivity as well as an increase in locomotor activity. Our results suggest that long-lasting biochemical and behavioral effects of alcohol may occur in the offspring starting at the earliest stage of development.
TL;DR: A faster ethanol elimination associated with a higher blood acetaldehyde level was observed in the Japanese subject as compared to Caucasian subjects, but no significant change in ADH and ALDH enzyme activities was detected as the result of acute ethanol intake.
TL;DR: Three different dehydrogenases able to oxidize formaldehyde were found in the Gram-positive methylotroph, Nocardia sp.
TL;DR: Kinetic data showed that placental ALDH isoenzyme had a high Km (in the millimolar range) and increased its activity raising the pH from 7.4 to 8.8, more than the hepatic ALDH I and ALDH II isoenzymes did.
TL;DR: The existence of this enzyme in mammalian brain seems to be related to a glutamate decarboxylase-independent pathway (alternative pathway) for GABA synthesis from putrescine.
Abstract: An enzyme which catalyses dehydrogenation of gamma-aminobutyraldehyde (ABAL) to gamma-aminobutyric acid (GABA) was purified to homogeneity from rat brain tissues by using DEAE-cellulose and affinity chromatography on 5'-AMP-Sepharose, phosphocellulose and Blue Agarose, followed by gel filtration. Such an enzyme was first purified from mammalian brain tissues, and was identified as an isoenzyme of aldehyde dehydrogenase. It has an Mr of 210,000 determined by polyacrylamide-gradient-gel electrophoresis, and appeared to be composed of subunits of Mr 50,000. The close similarity of substrate specificity toward acetaldehyde, propionaldehyde and glycolaldehyde between the enzyme and other aldehyde dehydrogenases previously reported was observed. But substrate specificity of the enzyme toward ABAL was higher than those of aldehyde dehydrogenases from human liver (E1 and E2), and was lower than those of ABAL dehydrogenases from human liver (E3), Escherichia coli and Pseudomonas species. The Mr and relative amino acid composition of the enzyme are also similar to those of E1 and E2. The existence of this enzyme in mammalian brain seems to be related to a glutamate decarboxylase-independent pathway (alternative pathway) for GABA synthesis from putrescine.
TL;DR: Results indicate that the increase in absorbance at 340 nm is not entirely due to NAD conversion to NADH, and it was observed that nonenzymatic interaction of NAD and aldehyde could as well result in increase in absorbsance at340 nm.
TL;DR: Differences in the ALDH distribution pattern in different rat hepatoma cell lines compared to normal rat hepatocytes are reported here and the tumor-associated aldehyde dehydrogenase is not detectable in normal hepatocytes.
TL;DR: The mean levels of all anzymes except Superoxide dismutase and aldehyde dehydrogenase in benign tissues were fairly similar to the mean levels found in normal tissue samples, and GSH transferase activity was decreased in malignant tissues relative to normal and benign tissues.
Abstract: Many anticancer drugs exert their cytotoxic effects via formation of oxygen free radicals. Cellular thiols, glutathione (GSH)-dependent enzymes and other redox enzymes are involved in the metabolism of these anticancer drugs and of the oxygen free radicals that may be generated during their metabolism. We quantified these biochemical parameters in cytosol from human ovarian tissues. We compared non-protein thiol levels, GSH transferase, GSH peroxidase, Superoxide dismutase, catalase, DT diaphorase and aldehyde dehydrogenase activity in serous ovarian tumors (n=15), other malignant ovarian tumors (n=12), benign ovarian tissue (n=10) and histologically normal ovarian tissue (n=12). Mean GSH transferase and DT diaphorase activitie were similar in serous and other malignant ovarian tumors. GSH transferase activity was decreased in malignant tissues relative to normal and benign tissues. Mean DT diaphorase and Superoxide dismutase activities were increased in the malignant tissues, although this was not statistically significant. The mean levels of all anzymes except Superoxide dismutase and aldehyde dehydrogenase in benign tissues were fairly similar to the mean levels found in normal tissue samples. Tissues from patients with serous ovarian tumors, who had received cyclophosphamide and cisplatin prior to surgery, also were analyzed (n=7). Except for aldehyde dehydrogenase, all the parameters measured were decreased in these samples relative to serous tissue from untreated patients. These biochemical analyses may be useful in understanding the mechanisms involved in the response to chemotherapy.
TL;DR: Lymphocytes appear to be an easily accessible and suitable tissue for determining type I ALDH phenotype.
Abstract: The types of isozymes of aldehyde dehydrogenase (ALDH) present in human lymphocytes has been investigated using isoelectric focusing of polyacrylamide gels followed by substrate-specific staining. Lymphocytes obtained from most individuals were found to contain both types I and II ALDH. This group of ‘typical’ individuals reported that they did not develop marked facial flushing or rapid heart rate after drinking alcohol nor did they develop an erythema to cutaneously applied ethanol. Lymphocytes obtained from ‘atypical’ individuals who do suffer from alcohol-induced flushing and rapid heart rate and who developed erythema to cutaneous ethanol displayed type II, but not type I, ALDH. Lymphocytes thus appear to be an easily accessible and suitable tissue for determining type I ALDH phenotype.
TL;DR: Aldehyde dehydrogenase was purified 187-fold from cytosol of rat testis by chromatographic methods and gel filtration with a yield of about 50%.
Abstract: Aldehyde dehydrogenase was purified 187-fold from cytosol of rat testis by chromatographic methods and gel filtration with a yield of about 50%. The enzyme exhibits absolute requirement for exogenous sulfhydryl compounds and strong dependence on temperature. Addition of 0.4mM Ca2 or Mg2 ions results in 50% inhibition. Optimally active at pH 8.5 and 50 degrees C, aldehyde dehydrogenase displays broad substrate specificity; saturation curves with acetaldehyde and propionaldehyde are non-hyperbolic, with Hill coefficients comprised between 0.8 and 0.7. Strong substrate inhibition can be observed with both aromatic and long-chain alyphatic aldehydes. According to mathematical models, Km decreases from 246 microM for acetaldehyde to 4 microM for capronaldehyde and Ki decreases from about 4mM for butyraldehyde to 0.2 mM for capronaldehyde.