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European Journal of Biochemistry Dec 1982Two monomeric NADPH enzymes from pig lens, an aldehyde reductase and an aldose reductase, have been characterized. The aldose reductase is obtained in a pure form. The... (Comparative Study)
Comparative Study
Two monomeric NADPH enzymes from pig lens, an aldehyde reductase and an aldose reductase, have been characterized. The aldose reductase is obtained in a pure form. The aldehyde reductase, usually called hexonate dehydrogenase, is the same protein as that was recently isolated from pig liver [Branlant, G. and Biellmann, J.F. (1980) Eur. J. Biochem. 105, 611-621]. The aldose reductase is shown to have a number of properties in common with the aldehyde reductase, namely its physico-chemical properties, its tendency to be inhibited by quercitine derivatives and its substrate specificity. These two enzymes differ in their immunological properties. Only aldose reductase has a reactive Cys residue, localized in or near the substrate binding site. In contrast to that shown for aldehyde reductase [Branlant, G. et al. (1981) Eur. J. Biochem. 116, 505-512; Branlant, G. (1982) Eur. J. Biochem. 121, 407-411], no anion-recognition sites are in the substrate binding site of aldose reductase. The fact that also sugars are substrates for aldose reductase support the idea that this enzyme is implicated in the formation of sugar cataract as suggested by Kinoshita, J.H. et al. [J. Am. Med. Ass. 246, 257-261 (1981)]. Pig lens aldose reductase does not show homotropic cooperative effects with respect to either substrate or coenzyme.
Topics: Alcohol Oxidoreductases; Aldehyde Reductase; Animals; Chemical Phenomena; Chemistry; Chemistry, Physical; Dithionitrobenzoic Acid; Lens, Crystalline; NADP; Substrate Specificity; Sugar Alcohol Dehydrogenases; Swine; Zinc
PubMed: 6819141
DOI: 10.1111/j.1432-1033.1982.tb07026.x -
Chemical & Pharmaceutical Bulletin Jun 1990Aldose reductase and aldehyde reductase from the medulla of the rat kidney have been purified to homogeneity by using affinity chromatography, gel filtration and...
Aldose reductase and aldehyde reductase from the medulla of the rat kidney have been purified to homogeneity by using affinity chromatography, gel filtration and chromatofocusing. The molecular weights of aldose reductase and aldehyde reductase by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis were found to be 37000 and 39000, respectively. The isoelectric points of aldose reductase and aldehyde reductase were found to be 5.4 and 6.2 by chromatofocusing, respectively. The major differences of amino acid compositions between both enzymes were found in serine, alanine and aspartic acid. Substrate specificity studies showed that aldose reductase utilized aldo-sugars such as D-glucose and D-galactose, but aldehyde reductase did not use them. The Km values of aldose reductase for various substrates were lower than those of aldehyde reductase. Aldose reductase utilized both reduced nicotinamide adenine dinucleotide phosphate (NADPH) and reduced nicotinamide adenine dinucleotide (NADH) as coenzymes, whereas aldehyde reductase utilized only NADPH. The presence of the sulfate ion resulted in a dramatic activation of aldose reductase whereas it did not affect aldehyde reductase activity. These enzymes were strongly inhibited by the known aldose reductase inhibitors. However, aldose reductase was more susceptible than aldehyde reductase to inhibition by the aldose reductase inhibitors.
Topics: Aldehyde Oxidoreductases; Aldehyde Reductase; Animals; Kidney Medulla; Male; Rats; Rats, Inbred Strains
PubMed: 2119895
DOI: 10.1248/cpb.38.1639 -
Recent Patents on Anti-cancer Drug... 2016Cytosolic NADPH-dependent reductase AKR1B10 is a member of the aldo-keto reductase (AKR) superfamily. This enzyme is normally expressed in the gastrointestinal tract.... (Review)
Review
Cytosolic NADPH-dependent reductase AKR1B10 is a member of the aldo-keto reductase (AKR) superfamily. This enzyme is normally expressed in the gastrointestinal tract. However, it is overexpressed in many solid tumors, such as hepatocarcinoma, lung cancer and breast cancer. AKR1B10 may play a role in the formation and development of carcinomas through multiple mechanisms including detoxification of cytotoxic carbonyls, modulation of retinoic acid level, and regulation of cellular fatty acid synthesis and lipid metabolism. Studies have suggested that AKR1B10 may be a useful biomarker for cancer diagnosis and a potential target for cancer treatment. Over the last decade, a number of AKR1B10 inhibitors including aldose reductase inhibitors (ARIs), endogenous substances, natural-based derivatives and synthetic compounds have been developed, which could be novel anticancer drugs. This review provides an overview on related articles and patents about AKR1B10 inhibitors, with a focus on their inhibition selectivity and mechanism of function.
Topics: Aldehyde Reductase; Aldo-Keto Reductases; Animals; Antineoplastic Agents; Enzyme Inhibitors; Humans; Neoplasms; Treatment Outcome
PubMed: 26844556
DOI: 10.2174/1574892811888160304113346 -
Progress in Retinal and Eye Research Jul 1998Kinetic studies on the aldose reductase protein (AR2) have shown that it does not behave as a classical enzyme in relation to ring aldose sugars. These results have been... (Review)
Review
Kinetic studies on the aldose reductase protein (AR2) have shown that it does not behave as a classical enzyme in relation to ring aldose sugars. These results have been confirmed by X-ray crystallography studies, which have pinpointed binding sites for pharmacological "aklose reductase inhibitors" (ARIs). As with non-enzymic glycation reactions, there is probably a free-radical element involved derived from monosaccharide autoxidation. In the case of AR2, there is free radical oxidation of NADPH by autoxidising monosaccharides, enhanced in the presence of the NADPH-binding protein. Whatever the behaviour of AR2, many studies have showed that sorbitol production is not an initiating aetiological factor in the development of diabetic complications in humans. Vitamin E (alpha-tocopherol), other antioxidants and high fat diets can delay or prevent cataract in diabetic animals even though sorbitol and fructose levels are not modified; vitamin C acts as an AR1 in humans. Protein post-translational modification by glyc-oxidation or other events is probably the key factor in the aetiology of diabetic complications. There is now no need to invoke AR2 in xylitol biosynthesis. Xylitol can be produced in the lens from glucose, via a pathway involving the enzymes myo-inositol-oxygen oxidoreductase, D-glucuronate reductase. L-gulonate NAD(+)-3-oxidoreductase and L-iditol-NAD(+)-5-oxidoreductase, all of which have recently been found in bovine and rat lens. This chapter investigates the molecular events underlying AR2 and its binding and kinetics. Induction of the protein by osmotic response elements is discussed, with detailed analysis of recent in vitro and in vivo experiments on numerous ARIs. These have a number of actions in the cell which are not specific, and which do not involve them binding to AR2. These include peroxy-radical scavenging and recently discovered effects of metal ion chelation. In controlled experiments, it has been found that incubation of rat lens homogenate with glucose and the copper chelator o-phenanthroline abolishes production of sorbitol. Taken together, these results suggest AR2 is a vestigial NADPH-binding protein, perhaps similar in function to a number of non-mammalian crystallins which have been recruited into the lens. There is mounting evidence for the binding of reactive aldehyde moieties to the protein, and the involvement of AR2 either as a 'housekeeping' protein, or in a free-radial-mediated 'catalytic' role. Interfering with the NADPH binding and flux levels--possibly involving free radicals and metal ions--has a deleterious effect. We have yet to determine whether aldose reductase is the black sheep of the aldehyde reductase family, or whether it is a skeleton in the cupboard, waiting to be clothed in the flesh of new revelations in the interactions between proteins, metal ions and redox metabolites.
Topics: Aldehyde Reductase; Animals; Cataract; Cattle; Diabetes Complications; Diabetes Mellitus; Diabetic Retinopathy; Enzyme Inhibitors; Humans; Lens, Crystalline; Rats; Retina; Sugar Alcohols
PubMed: 9695797
DOI: 10.1016/s1350-9462(97)00013-x -
The International Journal of... 19911. Aldose reductase and aldehyde reductase were purified to homogeneity from human testis. 2. The molecular weight of aldose reductase and aldehyde reductase were...
1. Aldose reductase and aldehyde reductase were purified to homogeneity from human testis. 2. The molecular weight of aldose reductase and aldehyde reductase were estimated to be 36,000 and 38,000 by SDS-PAGE, and the pI values of these enzymes were found to be 5.9 and 5.1 by chromatofocusing, respectively. 3. Aldose reductase had activity for aldo-sugars, whereas aldehyde reductase was virtually inactive for aldo-sugars. The Km values of aldose reductase for D-glucose, D-galactose and D-xylose were 57, 49 and 6.2 mM, respectively. Aldose reductase utilized both NADPH and NADH as coenzymes, whereas aldehyde reductase only NADPH. 4. Sulfate ion caused 3-fold activation of aldose reductase, but little for that of aldehyde reductase. 5. Sodium valproate inhibited significantly aldehyde reductase, but not aldose reductase. Aldose reductase was inhibited strongly by aldose reductase inhibitors being in clinical trials at concentrations of the order of 10(-7)-10(-9) M. Aldehyde reductase was also inhibited by these inhibitors, but its susceptibility was less than aldose reductase. 6. Reaction of aldose reductase with pyridoxal 5'-phosphate (PLP) resulted ca 2.5-fold activation, but aldehyde reductase did not cause the activation. PLP-treated aldose reductase has lost the susceptibility to aldose reductase inhibitor.
Topics: Alcohol Dehydrogenase; Aldehyde Reductase; Humans; Isoelectric Point; Kinetics; Male; Molecular Weight; Pyridoxal Phosphate; Substrate Specificity; Testis
PubMed: 1901806
DOI: 10.1016/0020-711x(91)90169-n -
Yeast (Chichester, England) Apr 2015The aldehyde reductase gene ARI1 is a recently characterized member of an intermediate subfamily within the short-chain dehydrogenase/reductase (SDR) superfamily that...
The aldehyde reductase gene ARI1 is a recently characterized member of an intermediate subfamily within the short-chain dehydrogenase/reductase (SDR) superfamily that clarified mechanisms of in situ detoxification of 2-furaldehyde and 5-hydroxymethyl-2-furaldehyde by Saccharomyces cerevisiae. Uncharacterized open reading frames (ORFs) are common among tolerant candidate genes identified for lignocellulose-to-advanced biofuels conversion. This study presents partially purified proteins of two ORFs, YDR541C and YGL039W, and direct enzyme assay evidence against aldehyde-inhibitory compounds commonly encountered during lignocellulosic biomass fermentation processes. Each of the partially purified proteins encoded by these ORFs showed a molecular mass of approximately 38 kDa, similar to Ari1p, a protein encoded by aldehyde reductase gene. Both proteins demonstrated strong aldehyde reduction activities toward 14 aldehyde substrates, with high levels of reduction activity for Ydr541cp toward both aromatic and aliphatic aldehydes. While Ydr541cp was observed to have a significantly higher specific enzyme activity at 20 U/mg using co-factor NADPH, Ygl039wp displayed a NADH preference at 25 U/mg in reduction of butylaldehyde. Amino acid sequence analysis identified a characteristic catalytic triad, Ser, Tyr and Lys; a conserved catalytic motif of Tyr-X-X-X-Lys; and a cofactor-binding sequence motif, Gly-X-X-Gly-X-X-Ala, near the N-terminus that are shared by Ydr541cp, Ygl039wp, Yol151wp/GRE2 and Ari1p. Findings of aldehyde reductase genes contribute to the yeast gene annotation and aids development of the next-generation biocatalyst for advanced biofuels production.
Topics: Aldehyde Reductase; Aldehydes; Amino Acid Motifs; Amino Acid Sequence; Enzyme Assays; Enzyme Stability; Kinetics; Molecular Sequence Data; NADP; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Sequence Alignment; Substrate Specificity
PubMed: 25656103
DOI: 10.1002/yea.3067 -
Biochemical Pharmacology Feb 1990Engelbreth-Holm-Swarm (EHS) tumor cells were utilized as a model for investigating the production of basement membrane components. These cells contain two... (Comparative Study)
Comparative Study
Engelbreth-Holm-Swarm (EHS) tumor cells were utilized as a model for investigating the production of basement membrane components. These cells contain two immunologically distinct NADPH-dependent reductases, aldose reductase (EC 1.1.1.21) and aldehyde reductase (EC 1.1.1.2), which were purified to apparent homogeneity by a combination of procedures which included ammonium sulfate fractionation, Sephadex G-75 gel filtration, Matrex Gel Orange A affinity chromatography, and chromatofocusing on Pharmacia Mono P. The molecular weights of aldose and aldehyde reductases were estimated to be 38K and 40K, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Substrate specificity studies showed that both enzymes were capable of reducing a variety of aldehydes to their respective alcohols; however, only aldehyde reductase oxidized L-gulonic acid. Surprisingly, both enzymes showed similar reactivities with D-glucose and D-galactose, suggesting that both aldose and aldehyde reductases may contribute to sorbitol production in the EHS tumor cell. The activities of both enzymes were increased by the presence of sulfate ion, but chloride ion decreased the activity of aldose reductase. Both aldose and aldehyde reductases were inhibited by a series of structurally diverse aldose reductase inhibitors.
Topics: Alcohol Dehydrogenase; Aldehyde Reductase; Amino Acids; Animals; Basement Membrane; Chromatography; Electrophoresis, Polyacrylamide Gel; Molecular Weight; NADP; Neoplasms, Experimental; Rats; Substrate Specificity; Sugar Alcohol Dehydrogenases
PubMed: 2106320
DOI: 10.1016/0006-2952(90)90049-q -
Biochemistry Sep 1995Human aldehyde reductase is a NADPH-dependent aldo-keto reductase that is closely related (65% identity) to aldose reductase, an enzyme involved in the pathogenesis of...
Human aldehyde reductase is a NADPH-dependent aldo-keto reductase that is closely related (65% identity) to aldose reductase, an enzyme involved in the pathogenesis of some diabetic and galactosemic complications. In aldose reductase, the active site residue Tyr48 is the proton donor in a hydrogen-bonding network involving residues Asp43/Lys77, while His110 directs the orientation of substrates in the active site pocket. Mutation of the homologous Tyr49 to phenylalamine or histidine (Y49F or Y49H) and of Lys79 to methionine (K79M) in aldehyde reductase yields inactive enzymes, indicating similar roles for these residues in the catalytic mechanism of aldehyde reductase. A H112Q mutant aldehyde reductase exhibited a substantial decrease in catalytic efficiency (kcat/Km) for hydrophilic (average 150-fold) and aromatic substrates (average 4200-fold) and 50-fold higher IC50 values for a variety of inhibitors than that of the wild-type enzyme. The data suggest that His112 plays a major role in determining the substrate specificity of aldehyde reductase, similar to that shown earlier for the homologous His110 in aldose reductase [Bohren, K. M., et. al. (1994) Biochemistry 33, 2021-2032]. Mutation of Ile298 or Val299 affected the kinetic parameters to a much lesser degree. Unlike native aldose reductase, which contains a thiol-sensitive Cys298, neither the I298C or V299C mutant exhibited any thiol sensitivity, suggesting a geometry of the active site pocket different from that in aldose reductase. Also different from aldose reductase, the detection of a significant primary deuterium isotope effect on kcat (1.48 +/- 0.02) shows that nucleotide exchange is only partially rate-limiting. Primary substrate and solvent deuterium isotope effects on the H112Q mutant suggest that hydride and proton transfers occur in two discrete steps with hydride transfer taking place first. Dissociation constants and spectroscopic and fluorimetric properties of nucleotide complexes with various mutants suggest that, in addition to Tyr49 and His112, Lys79 plays a hitherto unappreciated role in nucleotide binding. The mode of inhibition of aldehyde reductase by aldose reductase inhibitors (ARIs) is generally similar to that of aldose reductase and involves binding to the E:NADP+ complex, as shown by kinetic and direct inhibitor-binding experiments. The order of ARI potency was AL1576 (Ki = 60 nM) > tolrestat > ponalrestat > sorbinil > FK366 > zopolrestat > alrestatin (Ki = 148 microM). Our data on aldehyde reductase suggest that the active site pocket significantly differs from that of aldose reductase, possibly due to the participation of the C-terminal loop in its formation.
Topics: Aldehyde Reductase; Amino Acid Sequence; Base Sequence; Binding Sites; DNA Primers; Deuterium; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Kinetics; Molecular Sequence Data; Mutagenesis, Site-Directed; NADP; Protons; Recombinant Proteins; Substrate Specificity
PubMed: 7669785
DOI: 10.1021/bi00035a036 -
International Journal of Molecular... Jan 2021Aldose reductase (AR) is a member of the reduced nicotinamide adenosine dinucleotide phosphate (NADPH)-dependent aldo-keto reductase superfamily. It is also the... (Review)
Review
Aldose reductase (AR) is a member of the reduced nicotinamide adenosine dinucleotide phosphate (NADPH)-dependent aldo-keto reductase superfamily. It is also the rate-limiting enzyme of the polyol pathway, catalyzing the conversion of glucose to sorbitol, which is subsequently converted to fructose by sorbitol dehydrogenase. AR is highly expressed by Schwann cells in the peripheral nervous system (PNS). The excess glucose flux through AR of the polyol pathway under hyperglycemic conditions has been suggested to play a critical role in the development and progression of diabetic peripheral neuropathy (DPN). Despite the intensive basic and clinical studies over the past four decades, the significance of AR over-activation as the pathogenic mechanism of DPN remains to be elucidated. Moreover, the expected efficacy of some AR inhibitors in patients with DPN has been unsatisfactory, which prompted us to further investigate and review the understanding of the physiological and pathological roles of AR in the PNS. Particularly, the investigation of AR and the polyol pathway using immortalized Schwann cells established from normal and AR-deficient mice could shed light on the causal relationship between the metabolic abnormalities of Schwann cells and discordance of axon-Schwann cell interplay in DPN, and led to the development of better therapeutic strategies against DPN.
Topics: Aldehyde Reductase; Animals; Diabetes Mellitus; Enzyme Inhibitors; Glucose; Humans; Metabolic Networks and Pathways; Oxidation-Reduction; Polymers; Schwann Cells; Sorbitol
PubMed: 33494154
DOI: 10.3390/ijms22031031 -
Chemico-biological Interactions Jun 2019Autophagy is a dynamic recycling process that eliminates damaged proteins and cellular organelles to maintain cellular homeostasis. Aldose reductase (AR) catalyzes...
Autophagy is a dynamic recycling process that eliminates damaged proteins and cellular organelles to maintain cellular homeostasis. Aldose reductase (AR) catalyzes conversion of glucose to sorbitol. It also catalyzes the reduction of a broad array of saturated and unsaturated aldehydes. Recently we demonstrated that deletion of AR promotes pathological cardiac remodeling via excessive autophagy; however, the role of AR in starvation-induced autophagy has not been determined. To determine the role of AR in starvation-induced autophagy, WTC57/Bl6 mice were pretreated with the AR inhibitor sorbinil (0.2 g/L for 48 h) in drinking water, followed by 24 h fasting. We found that the sorbinil pretreatment in fed mice did not affect blood glucose levels, whereas, it decreased the blood glucose levels in fasting mice. In comparison with fed mice, the LC3II formation and LCII/LCI ratio were increased in the fasted mice hearts and sorbinil pretreatment further enhanced LC3II formation and LC3II/LC3I ratios in these hearts. Fasting-induced autophagy coincided with AMPK activation in the sorbinil pretreated fasted mice hearts. Autophagy and activation of AMPK was also induced in the gastrocnemius skeletal muscle of sorbinil pre-treated fasted mice. Induction of autophagy in the cardiac tissues of sorbinil pretreated fasted mice was accompanied by increased clearance of 4-hydroxytrans-2-nonenal-protein adducts. Taken together, these results indicate that the inhibition of AR during fasting activates autophagic response, increases clearance of aldehyde-protein adducts, which could serve as a mechanism to maintain cellular homeostasis during starvation.
Topics: Aldehyde Reductase; Aldehydes; Animals; Autophagy; Imidazolidines; Male; Mice; Mice, Inbred C57BL; Starvation
PubMed: 30998906
DOI: 10.1016/j.cbi.2019.04.014