Catalyzes the NADPH-dependent reduction of a wide variety of carbonyl-containing compounds to their corresponding alcohols with a broad range of catalytic efficiencies.
Aldose reductase has been shown to be expressed in large amount by human embryonic epithelial cells (EUE) in response to osmotic stress. This conclusion is the result of studies undertaken following the purification to homogeneity of two forms of a 35-kDa protein overexpressed in EUE cells grown in hypertonic saline culture medium as compared to EUE cells grown in isoosmotic medium. Amino-acid composition, molecular weight and partial internal amino-acid sequence showed that the above proteins are two different forms of aldose reductase. These findings were confirmed by the observation that aldose reductase activity increased about 150-fold in adapted cells and returned to basal levels in de-adapted cells.
J. Biol. Chem. 265, 9788-9792 (1990)[PubMed:2112546]
The complete amino acid sequence of human retina and muscle aldose reductase was determined by nucleotide analysis of cDNA clones isolated using synthetic oligonucleotide probes based on partial amino acid sequences of purified human psoas muscle aldose reductase. The cDNA sequence differs substantially in the noncoding and coding regions of recently published sequences of this enzyme. The mRNA for aldose reductase was abundantly expressed in HeLa cells, but only scarcely in a neuroblastoma cell line. Recombinant baculovirus containing one of the muscle cDNA clones was constructed and used to infect Spodoptera frugiperda (SF9) cells. A prominent protein with an apparent molecular size of 36 kDa was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the culture medium as well as in the homogenate of SF9 cells after 2 days of infection. Culture medium or the supernatant fraction of cell homogenates containing this protein had high aldose reductase activity which showed characteristics of the reported human enzyme. These findings indicate that the amino acid sequence reported in this paper represents human retina and muscle aldose reductase and that functional human aldose reductase can be expressed in large amounts in a baculovirus expression system. The result should facilitate refined structural analysis and the development of new specific aldose reductase inhibitors for the treatment of diabetic complications.
Doxorubicin (DOX) and daunorubicin (DAUN) are effective anticancer drugs; however, considerable interpatient variability exists in their pharmacokinetics. This may be caused by altered metabolism by nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in genes encoding aldo-keto reductases (AKRs) and carbonyl reductases. This study examined the effect of 27 ns-SNPs, in eight human genes, on the in vitro metabolism of both drugs to their major metabolites, doxorubicinol and daunorubicinol. Kinetic assays measured metabolite levels by high-performance liquid chromatography separation with fluorescence detection using purified, histidine-tagged, human wild-type, and variant enzymes. Maximal rate of activity (V(max)), substrate affinity (K(m)), turnover rate (k(cat)), and catalytic efficiency (k(cat)/K(m)) were determined. With DAUN as substrate, variants for three genes exhibited significant differences in these parameters compared with their wild-type counterparts: the A106T, R170C, and P180S variants significantly reduced metabolism compared with the AKR1C3 wild-type (V(max), 23-47% decrease; k(cat), 22-47%; k(cat)/K(m), 38-44%); the L311V variant of AKR1C4 significantly decreased V(max) (47% lower) and k(cat) and k(cat)/K(m) (both 43% lower); and the A142T variant of AKR7A2 significantly affected all kinetic parameters (V(max) and k(cat), 61% decrease; K(m), 156% increase; k(cat)/K(m), 85% decrease). With DOX, the R170C and P180S variants of AKR1C3 showed significantly reduced V(max) (41-44% decrease), k(cat) (39-45%), and k(cat)/K(m) (52-69%), whereas the A142T variant significantly altered all kinetic parameters for AKR7A2 (V(max), 41% decrease; k(cat), 44% decrease; K(m), 47% increase; k(cat)/K(m), 60% decrease). These findings suggest that ns-SNPs in human AKR1C3, AKR1C4, and AKR7A2 significantly decrease the in vitro metabolism of DOX and DAUN.
The chemical reactions and pathways involving carbohydrates, any of a group of organic compounds based of the general formula Cx(H2O)y. Includes the formation of carbohydrate derivatives by the addition of a carbohydrate residue to another molecule.
J. Biol. Chem. 265, 9788-9792 (1990)[PubMed:2112546]
The complete amino acid sequence of human retina and muscle aldose reductase was determined by nucleotide analysis of cDNA clones isolated using synthetic oligonucleotide probes based on partial amino acid sequences of purified human psoas muscle aldose reductase. The cDNA sequence differs substantially in the noncoding and coding regions of recently published sequences of this enzyme. The mRNA for aldose reductase was abundantly expressed in HeLa cells, but only scarcely in a neuroblastoma cell line. Recombinant baculovirus containing one of the muscle cDNA clones was constructed and used to infect Spodoptera frugiperda (SF9) cells. A prominent protein with an apparent molecular size of 36 kDa was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the culture medium as well as in the homogenate of SF9 cells after 2 days of infection. Culture medium or the supernatant fraction of cell homogenates containing this protein had high aldose reductase activity which showed characteristics of the reported human enzyme. These findings indicate that the amino acid sequence reported in this paper represents human retina and muscle aldose reductase and that functional human aldose reductase can be expressed in large amounts in a baculovirus expression system. The result should facilitate refined structural analysis and the development of new specific aldose reductase inhibitors for the treatment of diabetic complications.
The chemical reactions and pathways involving daunorubicin, a chemotherapeutic of the anthracycline family that is given as a treatment for some types of cancer.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Doxorubicin (DOX) and daunorubicin (DAUN) are effective anticancer drugs; however, considerable interpatient variability exists in their pharmacokinetics. This may be caused by altered metabolism by nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in genes encoding aldo-keto reductases (AKRs) and carbonyl reductases. This study examined the effect of 27 ns-SNPs, in eight human genes, on the in vitro metabolism of both drugs to their major metabolites, doxorubicinol and daunorubicinol. Kinetic assays measured metabolite levels by high-performance liquid chromatography separation with fluorescence detection using purified, histidine-tagged, human wild-type, and variant enzymes. Maximal rate of activity (V(max)), substrate affinity (K(m)), turnover rate (k(cat)), and catalytic efficiency (k(cat)/K(m)) were determined. With DAUN as substrate, variants for three genes exhibited significant differences in these parameters compared with their wild-type counterparts: the A106T, R170C, and P180S variants significantly reduced metabolism compared with the AKR1C3 wild-type (V(max), 23-47% decrease; k(cat), 22-47%; k(cat)/K(m), 38-44%); the L311V variant of AKR1C4 significantly decreased V(max) (47% lower) and k(cat) and k(cat)/K(m) (both 43% lower); and the A142T variant of AKR7A2 significantly affected all kinetic parameters (V(max) and k(cat), 61% decrease; K(m), 156% increase; k(cat)/K(m), 85% decrease). With DOX, the R170C and P180S variants of AKR1C3 showed significantly reduced V(max) (41-44% decrease), k(cat) (39-45%), and k(cat)/K(m) (52-69%), whereas the A142T variant significantly altered all kinetic parameters for AKR7A2 (V(max), 41% decrease; k(cat), 44% decrease; K(m), 47% increase; k(cat)/K(m), 60% decrease). These findings suggest that ns-SNPs in human AKR1C3, AKR1C4, and AKR7A2 significantly decrease the in vitro metabolism of DOX and DAUN.
Doxorubicin (DOX) and daunorubicin (DAUN) are effective anticancer drugs; however, considerable interpatient variability exists in their pharmacokinetics. This may be caused by altered metabolism by nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in genes encoding aldo-keto reductases (AKRs) and carbonyl reductases. This study examined the effect of 27 ns-SNPs, in eight human genes, on the in vitro metabolism of both drugs to their major metabolites, doxorubicinol and daunorubicinol. Kinetic assays measured metabolite levels by high-performance liquid chromatography separation with fluorescence detection using purified, histidine-tagged, human wild-type, and variant enzymes. Maximal rate of activity (V(max)), substrate affinity (K(m)), turnover rate (k(cat)), and catalytic efficiency (k(cat)/K(m)) were determined. With DAUN as substrate, variants for three genes exhibited significant differences in these parameters compared with their wild-type counterparts: the A106T, R170C, and P180S variants significantly reduced metabolism compared with the AKR1C3 wild-type (V(max), 23-47% decrease; k(cat), 22-47%; k(cat)/K(m), 38-44%); the L311V variant of AKR1C4 significantly decreased V(max) (47% lower) and k(cat) and k(cat)/K(m) (both 43% lower); and the A142T variant of AKR7A2 significantly affected all kinetic parameters (V(max) and k(cat), 61% decrease; K(m), 156% increase; k(cat)/K(m), 85% decrease). With DOX, the R170C and P180S variants of AKR1C3 showed significantly reduced V(max) (41-44% decrease), k(cat) (39-45%), and k(cat)/K(m) (52-69%), whereas the A142T variant significantly altered all kinetic parameters for AKR7A2 (V(max), 41% decrease; k(cat), 44% decrease; K(m), 47% increase; k(cat)/K(m), 60% decrease). These findings suggest that ns-SNPs in human AKR1C3, AKR1C4, and AKR7A2 significantly decrease the in vitro metabolism of DOX and DAUN.
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a disturbance in organismal or cellular homeostasis, usually, but not necessarily, exogenous (e.g. temperature, humidity, ionizing radiation).
Aldose reductase has been shown to be expressed in large amount by human embryonic epithelial cells (EUE) in response to osmotic stress. This conclusion is the result of studies undertaken following the purification to homogeneity of two forms of a 35-kDa protein overexpressed in EUE cells grown in hypertonic saline culture medium as compared to EUE cells grown in isoosmotic medium. Amino-acid composition, molecular weight and partial internal amino-acid sequence showed that the above proteins are two different forms of aldose reductase. These findings were confirmed by the observation that aldose reductase activity increased about 150-fold in adapted cells and returned to basal levels in de-adapted cells.
Modification of human placental aldose reductase by iodoacetate (IAA) led to a mol/mol binding of IAA, a 40% decrease in the kcat, a 3-5-fold increase in the Km,NADPH and Km,glyceraldehyde and a 600-fold increase in the Ki,sorbinil; determined at pH 6.0. NADPH and 2'-monophosphoadenosine 5'-diphosphoribose but neither glyceraldehyde nor sorbinil, prevented carboxymethylation-induced changes. Cleavage of [14C]IAA-modified enzyme by trypsin resulted in two radiolabeled peptides: Val-297 to Lys-307 and Val-297 to Phe-315. In both these peptides Cys-298 was the only radiolabeled residue. It is suggested that Cys-298 regulates the kinetic and inhibition properties of the enzyme, but does not participate in catalysis.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.
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