Showing papers on "Aldehyde dehydrogenase published in 1993"
TL;DR: Alleles that encode the high activity forms of alcohol dehydrogenase, as well as the mutantALDH2*2 allele were less frequent in alcoholics than in controls, and the presence ofALDH 2*2 was associated with slower alcohol metabolism and the most intense flushing.
Abstract: The alcohol-flush reaction occurs in Asians who inherit the mutant ALDH2*2 allele that produces an inactive aldehyde dehydrogenase enzyme. In these individuals, high blood acetaldehyde levels are believed to be the cause of the unpleasant symptoms that follow drinking. We measured the alcohol elimination rates and intensity of flushing in Chinese subjects in whom the alcohol dehydrogenase ADH2 and ALDH2 genotypes were determined. We also correlated ADH2, ADH3, and ALDH2 genotypes with drinking behavior in 100 Chinese men. We discovered that ADH2*2 and ADH3*1, alleles that encode the high activity forms of alcohol dehydrogenase, as well as the mutant ALDH2*2 allele were less frequent in alcoholics than in controls. The presence of ALDH2*2 was associated with slower alcohol metabolism and the most intense flushing. In those homozygous for ALDH2*1, the presence of two ADH2*2 alleles correlated with slightly faster alcohol metabolism and more intense flushing, although a great deal of variability in the latter was noted.
177 citations
TL;DR: Structurally related compounds surveyed inhibit ALDH-I, but only prunetin and 5-hydroxydaidzin (genistin) combine high selectivity and potency, although they are 7- to 15-fold less potent than daidzin.
Abstract: Human mitochondrial aldehyde dehydrogenase (ALDH-I) is potently, reversibly, and selectively inhibited by an isoflavone isolated from Radix puerariae and identified as daidzin, the 7-glucoside of 4',7-dihydroxyisoflavone. Kinetic analysis with formaldehyde as substrate reveals that daidzin inhibits ALDH-I competitively with respect to formaldehyde with a Ki of 40 nM, and uncompetitively with respect to the coenzyme NAD+. The human cytosolic aldehyde dehydrogenase isozyme (ALDH-II) is nearly 3 orders of magnitude less sensitive to daidzin inhibition. Daidzin does not inhibit human class I, II, or III alcohol dehydrogenases, nor does it have any significant effect on biological systems that are known to be affected by other isoflavones. Among more than 40 structurally related compounds surveyed, 12 inhibit ALDH-I, but only prunetin and 5-hydroxydaidzin (genistin) combine high selectivity and potency, although they are 7- to 15-fold less potent than daidzin. Structure-function relationships have established a basis for the design and synthesis of additional ALDH inhibitors that could both be yet more potent and specific.
161 citations
TL;DR: Because the presence of high activity and high Km mu-ADHs as well as low-activity ALDH1 were found in human esophageal mucosa, it is suggested that there may exist an accumulation of intracellular acetaldehyde during alcohol ingestion.
Abstract: Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) isoenzymes from surgical esophageal and gastric mucosa were compared by agarose isoelectric focusing. Two prominent ADH forms, designated mu 1 (equivalent to the recently reported mu-form) and mu 2, were expressed in all the 15 esophagus specimens studied, whereas only four of seven examined gastric specimens exhibited a weak to moderately strong mu 1-ADH activity band on the isoelectric focusing gels. pI values of the esophageal mu 1-ADH and mu 2-ADH, and the liver pi-ADH were determined to be 8.61, 8.13, and 8.90, respectively. mu-ADHs exhibited high Km for ethanol (12 mM) and low sensitivity to 4-methylpyrazole inhibition. ALDH3 (BB form) and ALDH1 were the major high- and low-Km aldehyde dehydrogenase in the esophagus, respectively. The ADH and ALDH activities were determined at pH 7.5 to be 751 +/- 78 and 29.9 +/- 3.0 nmol/min/g tissue, respectively (measured at 500 mM ethanol or at 200 microM acetaldehyde; mean +/- SEM; N = 15). The esophageal ADH activity was approximately 4-fold and the ALDH activity 20% that of the stomach enzyme. Because the presence of high activity and high Km mu-ADHs as well as low-activity ALDH1 were found in human esophageal mucosa, it is suggested that there may exist an accumulation of intracellular acetaldehyde during alcohol ingestion. This reactive and toxic metabolite may be involved in the pathogenesis of alcohol-induced esophageal disorders.
136 citations
TL;DR: The final two steps in the dmp operon-encoded meta-cleavage pathway for phenol degradation in Pseudomonas sp.
Abstract: The final two steps in the dmp operon-encoded meta-cleavage pathway for phenol degradation in Pseudomonas sp. strain CF600 involve conversion of 4-hydroxy-2-ketovalerate to pyruvate and acetyl coenzyme A (acetyl-CoA) by the enzymes 4-hydroxy-2-ketovalerate aldolase and aldehyde dehydrogenase (acylating) [acetaldehyde:NAD+ oxidoreductase (CoA acetylating), EC 1.2.1.10]. A procedure for purifying these two enzyme activities to homogeneity is reported here. The two activities were found to copurify through five different chromatography steps and ammonium sulfate fractionation, resulting in a preparation that contained approximately equal proportions of two polypeptides with molecular masses of 35 and 40 kDa. Amino-terminal sequencing revealed that the first six amino acids of each polypeptide were those deduced from the previously determined nucleotide sequences of the corresponding dmp operon-encoded genes. The isolated complex had a native molecular mass of 148 kDa, which is consistent with the presence of two of each polypeptide per complex. In addition to generating acetyl-CoA from acetaldehyde, CoA, and NAD+, the dehydrogenase was shown to acylate propionaldehyde, which would be generated by action of the meta-cleavage pathway enzymes on the substrates 3,4-dimethylcatechol and 4-methylcatechol. 4-Hydroxy-2-ketovalerate aldolase activity was stimulated by the addition of Mn2+ and, surprisingly, NADH to assay mixtures. The possible significance of the close physical association between these two polypeptides in ensuring efficient metabolism of the short-chain aldehyde generated by this pathway is discussed.
92 citations
TL;DR: GSH may play an important role in protection against the induction of ROS generation in the CNS and liver following exposure to toluene, in addition to existing studies on cytochrome P450 oxidation and aldehyde dehydrogenase oxidation.
90 citations
TL;DR: Associated with the oxazaphosphorine-specific acquired resistance exhibited by a human breast adenocarcinoma subline growing in monolayer culture, the MCF-7/OAP ALDH-3 was judged to be a novel class 3 aldehyde dehydrogenase.
84 citations
80 citations
TL;DR: It is suggested that aldehyde dehydrogenase found in the kidney may be a specific retinal dehydrogen enzyme, involved in vitamin A metabolism.
Abstract: A NAD-dependent aldehyde dehydrogenase (EC 1.2.1.3) which catalyzes the oxidation of retinal to retinoic acid was purified to homogeneity from rat kidney by using Affi-Gel blue affinity chromatography and chromatofocusing, followed by Mono-Q anion-exchange chromatography. The apparent molecular weight of the native enzyme determined by size-exclusion fast protein liquid chromatography was 140 000. Sodium dodecyl sulfate - polyacrylamide gel electrophoresis gave a subunit molecular weight of 53 000. The isoelectric point as measured by chromatofocusing was 8.5. The enzyme also catalyzed the oxidation of acetaldehyde, but showed much lower Km value for the retinal substrate. We suggest that aldehyde dehydrogenase found in the kidney may be a specific retinal dehydrogenase, involved in vitamin A metabolism.Key words: aldehyde dehydrogenase, vitamin A, retinal, retinoic acid, kidney.
72 citations
TL;DR: The expressed mitochondrial iso enzyme could be recognized by antibodies raised against rat mitochondrial ALDH, whereas the cytosolic isozyme could be recognizing by antibody raised against horse cytOSolic ALDH.
Abstract: The amino acid sequences of both human class 1 and 2 aldehyde dehydrogenase (ALDH) and the sequences of the genes coding for them are known. Based on this sequence data, we designed primers and isolated the full-length cDNAs encoding both isozymes from a human liver mRNA pool. cDNAs were subcloned in the plasmid pT7-7 and expressed in Escherichia coli with a yield of approximately 3 mg ALDH protein/liter of cell culture, although only one-third of the enzyme was soluble. The soluble recombinantly expressed ALDHs were purified to homogeneity using a hydroxyacetophenone-Sepharose affinity column. The mitochondrial isozyme had a subunit molecular weight of 55 kDa, an isoelectric point of 4.9, and a specific activity of 1.10 units/mg, which were in good agreement with that from the native enzyme. The expressed cytosolic isozyme had the same subunit molecular weight (55 kDa) and pI (5.4) as that reported for the native enzyme and had a specific activity of 0.26 units/mg. The expressed mitochondrial isozyme could be recognized by antibodies raised against rat mitochondrial ALDH, whereas the cytosolic isozyme could be recognized by antibody raised against horse cytosolic ALDH.
69 citations
TL;DR: The data suggest that MPP+ is reduced by lipoamide dehydrogenase, and the mechanism involved may be hydride transfer from the enzymes to MPP+, rather than a direct single-electron reduction.
66 citations
TL;DR: The ability of HL-ADH to oxidize aldehydes is much greater than previously thought and is established in accord with earlier studies using much higher enzyme concentrations where no lag phase was reported.
Abstract: The oxidation of aldehydes by horse liver alcohol dehydrogenase (HL-ADH) is more complex than previously recognized. At low enzyme concentrations and/or high aldehyde concentrations, a pronounced lag in the assay progress curve is observed when the reaction is monitored for NADH production at 340 nm. When the progress of the reaction is followed by 1H NMR spectroscopy, rapid dismutation of the aldehyde substrate into the corresponding acid and alcohol is observed during the lag phase. Steady-state production of NADH commences only after aldehyde concentrations drop below 5% of their initial value; thereafter, NADH production occurs with continuous adjustment of the equilibrium between aldehyde, alcohol, NADH, and NAD+. The steady-state NADH production exhibits normal Michaelis-Menten kinetics and is in accord with earlier studies using much higher enzyme concentrations where no lag phase was reported. These results establish that the ability of HL-ADH to oxidize aldehydes is much greater than previously thought. The relationship between aldehyde dismutase and aldehyde dehydrogenase activities of HL-ADH is discussed.
TL;DR: The data support earlier proposals for major roles for these corneal enzymes in assisting the cornea in protecting the eye against UVR-induced tissue damage.
Abstract: Adult male C57BL/6J inbred mice were subjected to ultraviolet radiation (UVR) exposure (302-nm peak wavelength; average intensity 282 microW/cm2) for 1 h and monitored for ocular aldehyde dehydrogenase (ALDH) and alcohol dehydrogenase (ADH) activity changes over a period of 25 days. Dramatic reductions in activities were observed by 4-6 days postexposure, resulting in enzyme levels of 15-16% of control animals. Major decreases in corneal enzyme levels were predominantly responsible for these changes. Ocular morphology was observed throughout using a photoslit-lamp biomicroscope, with maximum corneal clouding occurring at days 4-6. These data support earlier proposals for major roles for these corneal enzymes in assisting the cornea in protecting the eye against UVR-induced tissue damage.
TL;DR: Acetaldehyde production by H. pylori from exogenous or endogenous ethanol may be a pathogenetic mechanism behind mucosal injury associated with the organism.
TL;DR: Analysis of several studies tends to support the proposed structural function of ALDH in human cornea, and indicates that there is a correlation between the activity of GR and GST in the normal and a separate group of corneal disorders.
Abstract: Previously we have reported that various pathologic corneas exhibited a "diseased" two-band corneal aldehyde dehydrogenase (ALDH) zymogram after native polyacrylamide gel electrophoresis as compared with the three bands in the normal human cornea. Experimentally, such a "diseased" zymogram pattern could be induced by addition of reduced glutathione (GSH) to the normal corneal epithelial extract. This finding suggests that in vivo the conformation of corneal ALDH may be related to changes in the GSH redox system during the process of corneal diseases. To investigate this hypothesis in keratoconus corneal epithelial extracts and a separate group comprising other corneal disorders, mainly herpes keratitis, we indirectly measured the GSH turnover by assaying the activity of glutathione reductase (GR) which is responsible in producing GSH and glutathione s-transferase (GST), which converts GSH into mercapturic acid. Our results indicate that there is a correlation between the activity of GR and GST in the normal and the separate group of corneal disorders. Because GST is the first enzyme in the mercapturic acid pathway, which detoxifies xenobiotic substrates including aldehydes, as by-products of membrane lipid peroxidation, an elevated GSH turnover might be necessary to counteract oxidative threats. However, no correlation was found between corneal ALDH level with either GR or GST. On the other hand, keratoconus samples demonstrated a distinct enzymatic behavior that was in concordance with our earlier result in the corneal ALDH zymogram after isoelectric focusing. Furthermore, analysis of our several studies tends to support the proposed structural function of ALDH in human cornea.
TL;DR: Eighty-two Caucasian patients receiving treatment for alcohol-related problems and eighty four controls were DNA typed for variants in the alcohol dehydrogenase (ADH2 and ADH3) and mitochondrial aldehyde dehydrogenases (ALDH2) gene loci.
Abstract: Eighty-two Caucasian patients receiving treatment for alcohol-related problems and eighty four controls were DNA typed for variants in the alcohol dehydrogenase (ADH 2 and ADH 3 and mitochondrial aldehyde dehydrogenase (ALDH 2 ) gene loci. No association was observed between individual, or combined gene frequencies and the presence of alcohol-related problems
Journal Article•
TL;DR: It has been proposed that ALDH which can oxidize aldophosphamide, an intermediate metabolite produced from cycloph phosphamide, prevents the generation of tissue toxic phosphamide mustard within cells and the drug resistance of the murine cell line with high ALDH activity can be explained by this mechanism.
Abstract: Cyclophosphamide, an important cancer chemotherapeutic agent, has been shown to be effective against some types of cancer (Hilton, 1984a; Manthey and Sladek, 1989). However, both natural and acquired resistance to cyclophosphamide limits its utility in the clinic. Several investigators have observed a dramatic increase (about 200-fold) of cytosolic aldehyde dehydrogenase (ALDH, EC 1.2.1.3) activity in a cyclo-phosphamide-resistant murine leukemia cell line. It has been proposed that ALDH which can oxidize aldophosphamide, an intermediate metabolite produced from cyclophosphamide, prevents the generation of tissue toxic phosphamide mustard within cells (Manthey and Sladek, 1989; Russo et al., 1989). The drug resistance of the murine cell line with high ALDH activity can be explained by this mechanism.
TL;DR: Data demonstrate a novel means of inactivation of an NAD-dependent enzyme, namely the affinity-based modification of the enzyme NAD site by ADP-ribose, and suggest that nonenzymatic ADp-ribosylation may be responsible for modification of cysteine residues.
TL;DR: The data suggest that the Ahd-4 gene in murine cell cultures is regulated by three distinct mechanisms: Ah receptor-mediated induction by TCDD or benzo[a]pyrene, CYP1A1 metabolism-dependent repression, and Chr 7-mediated putative derepression.
Abstract: We have cloned and sequenced the murine AHD4 cDNA encoding the 'Class 3' cytosolic aldehyde dehydrogenase (ALDH-3c). The cDNA is 1722 bp in length, excluding the poly(A+) tail, and has 5' and 3' nontranslated regions of 174 bp and 186 bp, respectively. AHD4 encodes a protein of 453 amino acids, including the first methionine (M(r) = 50,466). The murine AHD4 protein is 91% and 80% similar to the rat and human ALDH3c proteins, respectively, 64% identical to the rat microsomal ALDH3 protein, and < 28% similar to ALDH 'Class 1' and 'Class 2' proteins. Surprisingly, in contrast to the rat gene that is expressed in both cell cultures and the intact liver, the murine Ahd-4 gene is inducible by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin) or benzo[a]pyrene in cell cultures but not in liver of the intact adult or newborn mouse. Southern hybridization analysis of mouse DNA probed with the full-length cDNA reveals that the Ahd-4 gene is likely to span less than a total of 15 kb, and was mapped to chromosome (Chr) 11 between the Mgat-1 and Shbg loci by analysis of two multilocus crosses. AHD4 mRNA levels are strikingly elevated in the untreated mouse hepatoma Hepa-1c1c7 mutant line c37 lacking CYP1A1 (aryl hydrocarbon hydroxylase) activity and in the untreated 14CoS/14CoS mouse cell line having a homozygous deletion of about 1.2 cM on Chr 7. Our data suggest that the Ahd-4 gene in murine cell cultures is regulated by three distinct mechanisms: Ah receptor-mediated induction by TCDD or benzo[a]pyrene, CYP1A1 metabolism-dependent repression, and Chr 7-mediated putative derepression.
TL;DR: DETC-MeSO was found to be a potent inhibitor of rat liver mitochondrial low Km ALDH both in vivo and in vitro, and that inhibition of cytochrome P450 by inhibitors such as NBI block the inhibition of low KM ALDH by DETC-me.
TL;DR: A number of aldehyde dehydrogenase isozymes are distinguished based on the separation by physicochemical methods, tissue and subcellular distributions, and enzymatic properties, and they exhibit relatively broad substrate specificities and can oxidize various biogenic and xenobiotic aliphatic and aromatic aldehydes including dopaldehyde and aminaldehydes.
Abstract: A number of aldehyde dehydrogenase isozymes are distinguished based on the separation by physicochemical methods,, tissue and subcellular distributions, and enzymatic properties. Although ALDH isozymes are usually assayed with short chain aliphatic aldehydes as substrate, they exhibit relatively broad substrate specificities and can oxidize various biogenic and xenobiotic aliphatic and aromatic aldehydes including dopaldehyde and aminaldehydes. However, their physiological substrates are not identified and the primary biological roles of individual ALDH isozymes are not yet clear.
TL;DR: It is demonstrated that, although to a lesser extent than aldehyde dehydrogenase, aldealdehyde reductase and glutathione-S-transferase also increase during carcinogenesis.
TL;DR: The human low Km aldehyde dehydrogenases, E1, E2 and E3, share many common catalytic features as mentioned in this paper, such as NAD as coenzyme, broad substrate specificity, low micro-molar Km values for short chain aliphatic aldehydes, and similar km values and maximal velocities with substrates such as imidazole acetaldehyde and the metabolites of monoamines like serotonin, dopamine and norepinephrine.
Abstract: The human “low Km” aldehyde dehydrogenases, E1, E2 and E3 share many common catalytic features. These include NAD as coenzyme, broad substrate specificity, low micro-molar Km values for short chain aliphatic aldehydes, and similar Km values and maximal velocities with substrates such as imidazole acetaldehyde and the metabolites of monoamines like serotonin, dopamine and norepinephrine (Ambroziak and Pietruszko, 1991). All three isozymes also catalyze the dehydrogenation of aminoaldehydes; however, the Km values of the E3 isozyme for these compounds are considerably lower (5 μM for γ-aminobutyraldehyde, Ambroziak and Pietruszko, 1991) than those of E1 and E2 isozymes (Km values for γ-aminobutyraldehyde, 800 μM and 500 μM, respectively, Ambroziak and Pietruszko, 1987). Work on enzymes like E1 and E2 from other species has demonstrated that both El-like (class 1) and E2-like (class 2) enzymes can catalyze the dehydrogenation of retinal to retinoic acid (Chen et al., 1994). There is good evidence for the involvement of the class 1 enzyme in mammalian eye development (McCaffery et al., 1991; Godbout et al., 1996). This enzyme may also be involved in prostaglandin metabolism (Westlund et al., 1994).
TL;DR: It is concluded that DEAB is a potent inhibitor of ALDH in vivo and has no effect on the mixed function oxidase activity as determined by antipyrine clearance.
Abstract: The compound 4-(diethylamino)benzaldehyde (DEAB) is a potent inhibitor of cytosolic (class 1) aldehyde dehydrogenase (ALDH) in vitro and can overcome cyclophosphamide resistance in murine leukemia cells characterized by their high content of ALDH. In this study, we examined the in vivo effect of DEAB in mice on ethanol metabolism and on antipyrine clearance as a measure of the microsomal mixed function oxidase activity. DEAB administered in doses of 50 and 100 mg/kg increased the blood acetaldehyde concentration and decreased the plasma acetate concentration in mice treated with ethanol. A pharmacokinetic approach demonstrated that DEAB in doses of 50 and 100 mg/kg inhibited the fraction of ethanol converted to acetate by 32.5 and 67.5%, respectively. This inhibition was comparable with that produced by disulfiram. DEAB produced optimal inhibition of ALDH 10-15 min after administration. DEAB did not change the half-life or the total clearance of antipyrine. We conclude that DEAB is a potent inhibitor of ALDH in vivo and has no effect on the mixed function oxidase activity as determined by antipyrine clearance.
Journal Article•
TL;DR: Analysis of the proteins of the cornea and surrounding tissue indicated that in both the cow and the human, changes in the nature and quantity of soluble proteins occurred, consistent with the proposal that ALDH3 plays a dual role in the absorption of UVR and the oxidation of peroxidic aldehydes in the mammalian cornea.
Abstract: Human corneal aldehyde dehydrogenase (designated ALDH3) was purified to homogeneity and characterised with respect to substrate specificity and inhibition by thiol reagents. The enzyme was present as a major soluble protein (5% of the total soluble protein) and was found to efficiently catalyse the oxidation of medium chain peroxidic aldehydes which may be found in the cornea. These findings are consistent with the proposal that ALDH3 plays a dual role in the absorption of UVR and in the oxidation of peroxidic aldehydes in the mammalian cornea. Disulfiram did not inhibit this enzyme under the conditions used in this study, however p-hydroxymercuribenzoate rapidly inactivated the enzyme. Analysis of the proteins of the cornea and surrounding tissue indicated that in both the cow and the human, changes in the nature and quantity of soluble proteins occurred. Phenotype variants of the ALDH3 were apparent in a small Australian population.
TL;DR: Aldehyde dehydrogenase, an enzyme with a broad substrate specificity and low Km values for short chain aliphatic aldehydes utilizes NAD as coenzyme, is universally distributed in mammalian livers and also at lower concentrations in other organs.
Abstract: Aldehyde dehydrogenase (EC 1.2.1.3), an enzyme with a broad substrate specificity and low Km values for short chain aliphatic aldehydes utilizes NAD as coenzyme, is universally distributed in mammalian livers and also at lower concentrations in other organs. The enzyme is a homotetramer of MW of ca. 220,000 (see review by Pietruszko, 1989). Because of its broad substrate specificity, it is frequently considered to be an enzyme of detoxication which functions in the organisms in oxidation of toxic aldehydes ingested in foodstuffs (see review by Jakoby and Ziegler, 1990). Metabolism of ethanol derived acetaldehyde, which is known to be catalyzed by this enzyme (Parrilla et al., 1974) is an example of detoxication role of aldehyde dehydrogenase. In the human liver the enzyme occurs as three known isozymes, El, E2 and E3; other isozymes not yet identified may exist.
TL;DR: The pharmacological upshot is that a relative oxazaphosphorine-insensitivity is conferred on those cells in which constitutive or induced expression of the relevant enzyme(s) occurs.
Abstract: Oxazaphosphorines such as cyclophosphamide are widely used in the treatment of certain neoplasms (Sladek, 1988). Because they are, perse, without cytotoxic activity, their metabolism, Figure 1, has been the subject of intensive investigation. In the course of these investigations, it was established that certain aldehyde dehydrogenases catalyze the irreversible detoxification of the oxazaphosphorines when they catalyze the oxidation of aldophosphamide to carboxyphosphamide. Class 1 aldehyde dehydrogenases, e.g., mouse AHD-2 and human ALDH-1, are particularly important in this regard (Manthey et al., 1990; Dockham et al., 1992). Other “aldehyde” dehydrogenases, e.g., human ALDH-2 and succinic semialdehyde dehydrogenase, also catalyze the reaction albeit less well as judged by Km values (Dockham et al., 1992). Still others, e.g., human ALDH-4, ALDH-5 and betaine aldehyde dehydrogenase, do not catalyze the reaction at all (Dockham et al., 1992). The pharmacological upshot is that a relative oxazaphosphorine-insensitivity is conferred on those cells in which constitutive or induced expression of the relevant enzyme(s) occurs.
TL;DR: Histochemical analyses showed the induction of ALDH, gamma-GT, DT-diaphorase and UDPGdH, and the depression of cytochrome P450IA1 in hepatic neoplasms, and marker enzyme histochemistry of neoplasm revealed heterogeneous populations of hepatocytes and absence of necrotic areas.
Abstract: Biochemical and histochemical studies were conducted in aflatoxin B1-induced liver tumors in adult rainbow trout. Specific activities of the phase I enzymes, ethoxyresorufin-O-deethylase (EROD), microsomal and cytosolic epoxide hydrolase (mEH and cEH), aldehyde dehydrogenase (ALDH) and DT-diaphorase, and the phase II enzymes, gamma-glutamyltransferase (gamma-GT), glutathione transferase (GST) and uridine diphosphoglucuronyl transferase (UDPGT) were measured. Cryostat sections of tumor and surrounding liver from the same cohorts were analyzed immunohistochemically for cytochrome P450IA1 and histochemically for ALDH (benzaldehyde and hexanal), DT-diaphorase, gamma-GT and uridine diphosphoglucuronyl dehydrogenase (UDPGdH). In tumor tissues, the largest biochemical changes were found with benzaldehyde dehydrogenase, where activity increased from undetectable levels to 7.4 nmol/min/mg protein, and gamma-GT, where activity increased 12-fold over controls. Increases in other enzymes ranged from 1.26 to 2.84 times that of control liver, except EROD, which decreased, and cEH and mEH, which were unchanged. Histochemical analyses showed the induction of ALDH, gamma-GT, DT-diaphorase and UDPGdH, and the depression of cytochrome P450IA1 in hepatic neoplasms. In addition, marker enzyme histochemistry of neoplasms revealed heterogeneous populations of hepatocytes and absence of necrotic areas.
Patent•
20 Dec 1993TL;DR: In this paper, a recombinant enzyme with alcohol and aldehyde dehydrogenase activity is described. DNA molecules encoding the recombinant polypeptides, vectors comprising such DNA molecules, host cells transformed by such vectors and processes for the production of such recombinant enzymes are provided.
Abstract: The present invention is directed to a recombinant enzymes having alcohol and aldehyde dehydrogenase activity which comprises one or mom recombinant polypeptides selected from the group consisting of polypeptides which are identified by SEQ ID NO 5, SEQ ID NO 6, SEQ ID NO 7, SEQ ID NO 8 and chimeric recombinant polypeptides that are a chimeric combination of at least two of the following amino acid sequences identified by SEQ ID NO 5, SEQ ID NO 6, SEQ ID NO 7, SEQ ID NO 8 and functional derivatives of the polypeptides identified above which contain addition, insertion, deletion and/or substitution of one or more amino acid residues, wherein said enzymatic polypeptides have said alcohol and aldehyde dehydrogenase activity. DNA molecules encoding the recombinant polypeptides, vectors comprising such DNA molecules, host cells transformed by such vectors and processes for the production of such recombinant enzymes are provided. Furthermore the recombinant enzymes having alcohol and aldehyde dehydrogenase activity are used for obtaining aldehydes, ketones or carboxylic acids, and specifically, 2-keto-L-gulonic acid an intermediate for the production of L-ascorbic acid (vitamin C).