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1.
Immunochemical characterizations of aldose reductase and aldehyde reductases I and II, partially purified by DEAE-cellulose (DE-52) column chromatography from human tissues, were carried out by immunotitration, using antisera raised against the homogenous preparations of human and bovine lens aldose reductase and human placenta aldehyde reductase I and aldehyde reductase II. Anti-aldose reductase antiserum cross-reacted with aldehyde reductase I, anti-aldehyde reductase I antiserum cross-reacted with aldose reductase and anti-aldehyde reductase II antiserum precipitated aldehyde reductase II, but did not cross-react with aldose reductase or aldehyde reductase I from all the tissues examined. DE-52 elution profiles, substrate specificity and immunochemical characterization indicate that aldose reductase is present in human aorta, brain, erythrocyte and muscle; aldehyde reductase I is present in human kidney, liver and placenta; and aldehyde reductase II is present in human brain, erythrocyte, kidney, liver, lung and placenta. Monospecific anti-α and anti-β antisera were purified from placenta anti-aldehyde reductase I antiserum, using immunoaffinity techniques. Anti-α antiserum precipitated both aldehyde reductase I and aldose reductase, whereas anti-β antibodies cross-reacted with only aldehyde reductase I. Based on these studies, a three gene loci model is proposed to explain the genetic interrelationships among these enzymes. Aldose reductase is a monomer of α subunits, aldehyde reductase I is a dimer of α and β subunits and aldehyde reductase II is a monomer of δ subunits.  相似文献   

2.
By a procedure involving ammonium sulfate precipitation, gel filtration, and affinity chromatography, four aldehyde reductases (ALRs) were purified to enzymatic homogeneity from pig brain. These enzymes, designated ALR1, ALR2, ALR3, and succinic semialdehyde reductase were chemically and physically identical with, respectively, the high-Km aldehyde reductase, the low-Km aldehyde reductase, carbonyl reductase, and succinic semialdehyde reductase of other tissues and species. The purification procedure allows the purification of these enzymes from the same tissue homogenate in amounts sufficient for characterization and other enzymatic studies. This methodology should be applicable to the simultaneous and rapid purification of aldehyde reductases from other tissues.  相似文献   

3.
Aldose reductase and aldehyde reductases have been purified to homogeneity from human kidney and have molecular weights of 32,000 and 40,000 and isoelectric pH 5.8 and 5.3, respectively. Aldose reductase, beside catalyzing the reduction of various aldehydes, reduces aldo-sugars, whereas aldehyde reductase, does not reduce aldo-sugars. Aldose reductase activity is expressed with either NADH or NADPH as cofactor, whereas aldehyde reductase utilizes only NADPH. Both enzymes are inhibited to varying degrees by aldose reductase inhibitors. Antibodies against bovine lens aldose reductase precipitated aldose reductase but not aldehyde reductase. The sequence of addition of the substrates to aldehyde reductase is ordered and to aldose reductase is random, whereas for both the enzymes the release of product is ordered with NADP released last.  相似文献   

4.
Circular dichroism and fluorescence spectra of aldose reductase (E.C.1.1.1.21) and aldehyde reductase II (E.C.1.1.1.19) purified to homogeneity from human placenta have been studied. The alpha helical content of aldose reductase and aldehyde reductase II was 51% and 56%, respectively, whereas no beta helical structure was found in either case. In the case of aldose reductase, the secondary structure was unaffected at alkaline pH (9.5), whereas a drastic alteration in the structure was observed at 58 degrees C. The secondary structure of aldehyde reductase II, on the other hand, remained unaffected at higher pH and temperature.  相似文献   

5.
An NADPH-dependent aldehyde reductase (ALR) isolated from a red yeast, Sporobolomyces salmonicolor, catalyzes the reduction of a variety of carbonyl compounds. To investigate its primary structure, we cloned and sequenced the cDNA coding for ALR. The aldehyde reductase gene (ALR) comprises 969 bp and encodes a polypeptide of 35,232 Da. The deduced amino acid sequence showed a high degree of similarity to other members of the aldo-keto reductase superfamily. Analysis of the genomic DNA sequence indicated that the ALR gene was interrupted by six introns (two in the 5' noncoding region and four in the coding region). Southern hybridization analysis of the genomic DNA from S. salmonicolor indicated that there was one copy of the gene. The ALR gene was expressed in Escherichia coli under the control of the tac promoter. The enzyme expressed in E. coli was purified to homogeneity and showed the same catalytic properties as did the enzyme from S. salmonicolor.  相似文献   

6.
The life cycle transformation of the protozoan parasite Leishmania from promastigote to amastigote is accompanied by changes in the level of expression of a number of proteins whose function may be necessary for parasite survival in the sandfly vector or mammalian host. To genetically characterize these proteins, we have cloned and characterized cDNA sequences that vary in abundance during the life cycle of Leishmania major. One sequence (P100/11E) encodes a poly(A+) RNA whose abundance is markedly elevated in promastigotes of L. major. The DNA sequence of the P100/11E cDNA predicts an acidic polypeptide of Mr = 32,000 which shows 40-46% similarity to the superfamily of reductase proteins including 2,5-diketo-D-gluconic acid reductase, aldose reductase, aldehyde reductase, and rho-crystallin. The P100/11E sequence of L. major contains the IPKS motif located at the active site of both aldose and aldehyde reductases. The P100/11H sequence was expressed in Escherichia coli, and the purified polypeptide was used to raise rabbit antisera which detect a protein of Mr = 35,000 in promastigotes of L. major. These results provide direct genetic evidence that L. major expresses a sequence homologous to the reductase superfamily as a developmentally regulated gene product in promastigotes.  相似文献   

7.
We have proposed earlier a three gene loci model to explain the expression of the aldo-keto reductases in human tissues. According to this model, aldose reductase is a monomer of alpha subunits, aldehyde reductase I is a dimer of alpha, beta subunits, and aldehyde reductase II is a monomer of delta subunits. Using immunoaffinity methods, we have isolated the subunits of aldehyde reductase I (alpha and beta) and characterized them by immunocompetition studies. It is observed that the two subunits of aldehyde reductase I are weakly held together in the holoenzyme and can be dissociated under high ionic conditions. Aldose reductase (alpha subunits) was generated from human placenta and liver aldehyde reductase I by ammonium sulfate (80% saturation). The kinetic, structural and immunological properties of the generated aldose reductase are similar to the aldose reductase obtained from the human erythrocytes and bovine lens. The main characteristic of the generated enzyme is the requirement of Li2SO4 (0.4 M) for the expression of maximum enzyme activity, and its Km for glucose is less than 50 mM, whereas the parent enzyme, aldehyde reductase I, is completely inhibited by 0.4 M Li2SO4 and its Km for glucose is more than 200 mM. The beta subunits of aldehyde reductase I did not have enzyme activity but cross-reacted with anti-aldehyde reductase I antiserum. The beta subunits hybridized with the alpha subunits of placenta aldehyde reductase I, and aldose reductase purified from human brain and bovine lens. The hybridized enzyme had the characteristic properties of placenta aldehyde reductase I.  相似文献   

8.
Aldose reductase (EC 1.1.1.21) and aldehyde reductase II (L-hexonate dehydrogenase, EC 1.1.1.2) have been purified to homogeneity from human erythrocytes by using ion-exchange chromatography, chromatofocusing, affinity chromatography, and Sephadex gel filtration. Both enzymes are monomeric, Mr 32,500, by the criteria of the Sephadex gel filtration and polyacrylamide slab gel electrophoresis under denaturing conditions. The isoelectric pH's for aldose reductase and aldehyde reductase II were determined to be 5.47 and 5.06, respectively. Substrate specificity studies showed that aldose reductase, besides catalyzing the reduction of various aldehydes such as propionaldehyde, pyridine-3-aldehyde and glyceraldehyde, utilizes aldo-sugars such as glucose and galactose. Aldehyde reductase II, however, did not use aldo-sugars as substrate. Aldose reductase activity is expressed with either NADH or NADPH as cofactors, whereas aldehyde reductase II can utilize only NADPH. The pH optima for aldose reductase and aldehyde reductase II are 6.2 and 7.0, respectively. Both enzymes are susceptible to the inhibition by p-hydroxymercuribenzoate and N-ethylmaleimide. They are also inhibited to varying degrees by aldose reductase inhibitors such as sorbinil, alrestatin, quercetrin, tetramethylene glutaric acid, and sodium phenobarbital. The presence of 0.4 M lithium sulfate in the assay mixture is essential for the full expression of aldose reductase activity whereas it completely inhibits aldehyde reductase II. Amino acid compositions and immunological studies further show that erythrocyte aldose reductase is similar to human and bovine lens aldose reductase, and that aldehyde reductase II is similar to human liver and brain aldehyde reductase II.  相似文献   

9.
The neuromodulator gamma-hydroxybutyrate is synthesized in vivo from gamma-aminobutyrate by transamination to succinic semialdehyde and subsequent reduction of the aldehyde group. In human brain, succinic semialdehyde reductase is thought to be responsible for the conversion of succinic semialdehyde to gamma-hydroxybutyrate. In the present work, we cloned the cDNA coding for succinic semialdehyde reductase and expressed it in Escherichia coli. A data bank search indicated that the enzyme is identical with aflatoxin B1-aldehyde reductase, an enzyme implicated in the detoxification of xenobiotic carbonyl compounds. Structurally, succinic semialdehyde reductase thus belongs to the aldo-keto reductase superfamily. The recombinant protein was indistinguishable from native human brain succinic semialdehyde reductase by SDS/PAGE. In addition to succinic semialdehyde, it readily catalyzed the reduction 9,10-phenanthrene quinone, phenylglyoxal and 4-nitrobenzaldehyde, typical substrates of aflatoxin B1 aldehyde reductase. The results suggest multiple functions of succinic semialdehyde reductase/aflatoxin B1 aldehyde reductase in the biosynthesis of gamma-hydroxybutyrate and the detoxification of xenobiotic carbonyl compounds, respectively.  相似文献   

10.
We have propsed earlier a three gene loci model to explain the expression of the aldo-keto reductases in human tissues. According to this model, aldose reductase is a monomer of α subunits, aldehyde reductase I is a dimer of α, β subunits, and aldehyde reductase II is a monomer of δ subunits. Using immunoaffinity methods, we have isolated the subunits of aldehyde reductase I (α and β) and characterized them by immunocompetition studies. It is observed that the two subunits of aldehyde reductase I are weakly held together in the holoenzyme and can be dissociated under high ionic conditions. Aldose reductase (α subunits) was generated from human placenta and liver aldehyde reductase I by ammonium sulfate (80% saturation). The kinetic, structural and immunological properties of the generated aldose reductase are similar to the aldose reductase obtained from the human erythrocytes and bovine lens. The main characteristic of the generated enzyme is the requirement of Li2SO4(0.4 M) for the expression of maximum enzyme activity, and its Km for glucose is less than 50 mM, whereas the parent enzyme, aldehyde reductase I, is completely inhibited by 0.4 M Li2SO4 and its Km for glucose is more than 200 mM. The β subunits of aldehyde reductase I did not have enzyme activity but cross-reacted with anti-aldehyde reductase I antiserum. The β subunits hybridized with the α subunits of placenta aldehyde I, and aldose reductase purified from human brain and bovine lens. The hybridized enzyme had the characteristics properties of placenta aldehyde reductase I.  相似文献   

11.
Immunochemical characterization of aldo-keto reductases from human tissues   总被引:1,自引:0,他引:1  
H P Wirth  B Wermuth 《FEBS letters》1985,187(2):280-282
Aldose reductase, aldehyde reductase and carbonyl reductase constitute a family of monomeric NADPH-dependent oxidoreductases with similar physical and chemical properties. Characterization of the enzymes from human tissues by immunotitration and an enzyme immunoassay indicated that, despite their apparent likeness, the three reductases do not cross-react immunochemically.  相似文献   

12.
A 30,000 MW, barbiturate sensitive TPNH-linked aldehyde reductase which reduces aromatic aldehydes (3-pyridinecarboxaldehyde, 4-nitrobenzaldehyde, 4-cyanobenzaldehyde), d-glyceraldehyde, d-glucuronate and (+)-camphorquinone was found in liver, kidney, brain and heart tissue from a variety of animals. In livers, rabbit kidney, rabbit heart, and bovine brain a high molecular weight reductase was also found, which was less sensitive to barbiturate inhibition and had higher reactivity for cyclohexanone and d-ribose. The low molecular weight, TPNH-linked aldehyde reductases are probably homologous and should be classified under the systematic name alcohol:NADP oxidoreductase (EC 1.1.1.2). Since the substrate specificity of aldehyde reductase overlaps several previously described TPNH-linked reductases from the same tissues, reexamination of the properties of these enzymes for reclassification as EC 1.1.1.2 is necessary.  相似文献   

13.
Complementary DNA clones encoding 3 alpha-hydroxysteroid dehydrogenase (3 alpha HSD) were isolated from a rat liver cDNA lambda gt11 expression library using monoclonal antibodies as probes. The sizes of the cDNA inserts ranged from 1.3-2.3 kilobases. Sequence analysis indicated that variation in the DNA size was due to heterogeneity in the length of 3' noncoding sequences. A full-length cDNA clone of 1286 basepairs contained an open reading frame encoding a protein of 322 amino acids with an estimated mol wt of 37 kDa. When expressed in E. coli, the encoded protein migrated to the same position on sodium dodecyl sulfate-polyacrylamide gels as the enzyme purified from rat liver cytosols. The protein expressed in bacteria was highly active in androsterone reduction in the presence of NAD as cofactor, and this activity was inhibited by indomethacin, a potent inhibitor of 3 alpha HSD. The predicted amino acid sequence of 3 alpha HSD was related to sequences of several other enzymes, including bovine prostaglandin F synthase, human chlordecone reductase, human aldose reductase, human aldehyde reductase, and frog lens epsilon-crystalline, suggesting that these proteins belong to the same gene family.  相似文献   

14.
Characterization of aldose reductase and aldehyde reductase from rat testis   总被引:4,自引:0,他引:4  
Aldose reductase (alditol:NAD(P)+ 1-oxidoreductase, EC 1.1.1.21) and aldehyde reductase (alcohol:NADP+ oxidoreductase, EC 1.1.1.2) were purified to a homogeneity from rat testis. The molecular weights of aldose reductase and aldehyde reductase were estimated to be 38,000 and 41,000 by SDS-polyacrylamide gel electrophoresis, and the pI values of these enzymes were found to be 5.3 and 6.1 by chromatofocusing, respectively. Aldose reductase had activity for aldo-sugars such as xylose, glucose and galactose, whereas aldehyde reductase was virtually inactive for these aldo-sugars. The Km values of aldose reductase for aldo-sugars were relatively high. When a correction was made for the fraction of aldo-sugar present as the aldehyde form, which is the real substrate of the enzyme, the Km values were much lower. Aldose reductase utilized both NADPH and NADH as coenzyme, whereas aldehyde reductase utilized only NADPH. Aldose reductase was activated significantly by sulfate ion, while aldehyde reductase was little affected. Both enzymes were inhibited strongly by the known aldose reductase inhibitors. However, aldehyde reductase was in general less susceptible to these inhibitors when compared to aldose reductase. Both aldose reductase and aldehyde reductase treated with pyridoxal 5-phosphate have lost the susceptibility to aldose reductase inhibitor, suggesting that in these two enzymes aldose reductase inhibitor interacts with a lysine residue.  相似文献   

15.
During the purification of pig kidney aldehyde reductase by an established procedure [Flynn, Cromlish & Davidson (1982) Methods Enzymol. 89, 501-506] a second enzyme with aldehyde reductase activity may be purified. When the procedure was performed in the presence of 5 mM-EDTA, only traces of the second reductase, pig kidney aldehyde reductase (minor form), were present. By the criterion of sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, pig kidney aldehyde reductase (minor form) had Mr 35 000, in comparison with Mr 40 200 found for pig kidney aldehyde reductase. Amino acid analysis of both enzymes and tryptic-peptide-map comparisons indicated differences in primary structure. The N-terminus of pig kidney aldehyde reductase (minor form) had the sequence Lys-Val-Leu, in contrast with the blocked (acetylated) N-terminus of pig kidney aldehyde reductase. The C-terminal sequence of both enzymes was the same. Both reductases were immunologically identical by double immunodiffusion and rocket immunoelectrophoresis. Pig kidney aldehyde reductase (minor form) had 50% of the specific activity of pig kidney aldehyde reductase when tested with a variety of aldehyde substrates. Michaelis constants of both enzymes for these substrates and for NADPH were similar, but values for kcat. and kcat./Km indicated that catalytically pig kidney aldehyde reductase was the more efficient enzyme. Typical aldehyde reductase inhibitors, such as phenobarbital and sodium valproate, had the same effect on both enzymes. It was concluded that pig kidney aldehyde reductase (minor form) is an enzymically active cleavage product of pig kidney aldehyde reductase which is formed when the latter is purified in the absence of the metalloproteinase inhibitor EDTA.  相似文献   

16.
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.  相似文献   

17.
Farnesol (FOH) and geranylgeraniol (GGOH) with multiple biological actions are produced from the mevalonate pathway, and catabolized into farnesoic acid and geranylgeranoic acid, respectively, via the aldehyde intermediates (farnesal and geranylgeranial). We investigated the intracellular distribution, sequences and properties of the oxidoreductases responsible for the metabolic steps in rat tissues. The oxidation of FOH and GGOH into their aldehyde intermediates were mainly mediated by alcohol dehydrogenases 1 (in the liver and colon) and 7 (in the stomach and lung), and the subsequent step into the carboxylic acids was catalyzed by a microsomal aldehyde dehydrogenase. In addition, high reductase activity catalyzing the aldehyde intermediates into FOH (or GGOH) was detected in the cytosols of the extra-hepatic tissues, where the major reductase was identified as aldo-keto reductase (AKR) 1C15. Human reductases with similar specificity were identified as AKR1B10 and AKR1C3, which most efficiently reduced farnesal and geranylgeranial among seven enzymes in the AKR1A-1C subfamilies. The overall metabolism from FOH to farnesoic acid in cultured cells was significantly decreased by overexpression of AKR1C15, and increased by addition of AKR1C3 inhibitors, tolfenamic acid and R-flurbiprofen. Thus, AKRs (1C15 in rats, and 1B10 and 1C3 in humans) may play an important role in controlling the bioavailability of FOH and GGOH.  相似文献   

18.
In the present study, we investigated the differentially expressed proteins associated with ulcerative colitis (UC) using proteomic methods. Two-dimensional electrophoresis (2-DE) technology was performed to separate the total proteins of ulcerative tissues from those of the normal tissues of UC patients. PDQuest software was applied to analyze the obtained 2-DE images. Candidate protein spots between the two groups were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and bioinformatics analysis. The well resolution and reproducible 2-DE patterns of UC and normal tissues were established. Of the 12 differentially expressed proteins, 9 were successfully identified, of which 6 proteins were up-regulated including apolipoprotein C-III, haptoglobin, receptor tyrosine kinase, aldehyde reductase, pericentriolar material 1, and heat shock factor protein 2, and 3 were down-regulated including keratin, filamin A-interacting protein 1, and tropomyosin 3. These identified proteins were related to hormonal modulation, immune response, oxidative stress, and signal conduction. The 2-DE protein expression profile of the UC tissues displays an obvious difference from that of the normal controls. Various proteins may be involved in the occurrence of UC.  相似文献   

19.
使用DEAE纤维素柱层析、PBE-94层析聚焦、NADP~+-Sepharose 4B亲合层析及SephadexG-100凝胶过滤分离纯化了人脑醛糖还原酶。在DEAE层析中,用咪唑-HCI缓冲液替代了磷酸缓冲液,改善了分离效果。在聚丙烯酰胺及SDS聚丙烯酰胺凝胶电泳中,纯化的人脑醛糖还原酶均呈一条区带。它的pI为5.6,最适pH为6.5,分子量为36,000,底物特异性和氨基酸组成与其它哺乳动物的醛糖还原酶有相似性。开链式醛糖是醛糖还原酶的真正底物,它在开链式和半缩醛的平衡体系中占比例极小,因而推知醛糖还原酶对此底物有很高的K_(cat)和K_(cat)/K_m值,能有效地将它们还原成相应的醇。  相似文献   

20.
Three kinds of NADPH-dependent aldehyde reducing enzymes were present in the dog kidney. Aldose reductase was located in the inner medulla region and aldehyde reductase in all regions of the renal cortex, outer medulla and inner medulla. In addition, a new reductase designated tentatively as high-Km aldose reductase, which was converted into an aldose reductase-like enzyme, was present in the inner medulla region of the kidney. Aldose reductase, aldehyde reductase and high-Km aldose reductase were purified to homogeneity from each region of the dog kidney. The molecular weight of aldose reductase was estimated to be 38,500 by SDS-polyacrylamide gel electrophoresis and the isoelectric point was found to be 5.7 by chromatofocusing. Aldose reductase had activity for aldo-sugars such as D-xylose, D-glucose and D-galactose as substrates and utilized both NADPH and NADH as coenzymes. Sulfate ions resulted in over 2-fold activation of aldose reductase. All aldehyde reductases from the three regions had the same properties. The molecular weights and isoelectric points of aldehyde reductases were 40,000 and 6.1, respectively. The aldehyde reductases were inactive for D-hexose, utilized only NADPH as coenzyme and were not affected by sulfate ions. High-Km aldose reductase had a molecular weight of 38,500 and an isoelectric point of 5.4. It had activity for aldo-sugars, but showed much higher Km and lower kcat/Km values than aldose reductase. Sulfate ions inhibited high-Km aldose reductase. It was converted into an aldose reductase-like enzyme by incubation in phosphate buffer at pH 7.0. The three kinds of enzymes were strongly inhibited by the known aldose reductase inhibitors. However, aldehyde reductase and high-Km aldose reductase were, in general, less susceptible than aldose reductase.  相似文献   

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