Dehydrogenase/reductase (SDR family) member 7 (DHRS7, retSDR4, SDR34C1) is a previously uncharacterized member of the short-chain dehydrogenase/reductase (SDR) superfamily. While human SDR members are known to play an important role in various (patho)biochemical pathways including intermediary metabolism and biotransformation of xenobiotics, only 20% of them are considered to be well characterized. Based on phylogenetic tree and SDR sequence clusters analysis DHRS7 is a close relative to well-known SDR member 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) that participates in metabolism of endogenous and xenobiotic substances with carbonyl group. The aim of present study is to determine the basic biochemical properties of DHRS7 and its possible involvement in metabolism of substrates with carbonyl group. For the first time the computational predictions of this membrane protein and membrane topology were experimentally confirmed. DHRS7 has been demonstrated to be an integral protein facing the lumen of the endoplasmic reticulum with lack of posttranscriptional glycosylation modification. Subsequently, NADP(H) cofactor preference and enzymatic reducing activity of DHRS7 was determined towards endogenous substrates with a steroid structure (cortisone, 4-androstene-3,17-dion) and also toward relevant exogenous substances bearing a carbonyl group harmful to human health (1,2-naphtoquinone, 9,10-phenantrenequinone). In addition to 11β-HSD1, DHRS7 is another enzyme from SDR superfamily that have been proved, at least in vitro, to contribute to the metabolism of xenobiotics with carbonyl group.

• MeSH
• 11-beta-hydroxysteroiddehydrogenasa typ 1 chemie   metabolismus   MeSH
• benzaldehydy metabolismus   MeSH
• fluorescenční protilátková technika MeSH
• intracelulární membrány metabolismus   MeSH
• izoenzymy chemie   metabolismus   MeSH
• jaterní mikrozomy enzymologie   MeSH
• kinetika MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• NAD metabolismus   MeSH
• NADP metabolismus   MeSH
• nitrosaminy chemie   metabolismus   MeSH
• oxidoreduktasy chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• Sf9 buňky MeSH
• spektrofotometrie MeSH
• substrátová specifita MeSH
• ultracentrifugace MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Bupropion is widely used as an antidepressant drug and also as a smoking cessation aid. In humans, this drug is extensively metabolized to form several metabolites. Oxidised hydroxybupropion and two reduced metabolites, threohydrobupropion and erythrohydrobupropion, are major metabolites. All of these metabolites are considered to be active. Although the oxidative metabolic pathway and the central role of CYP2B6 are known, the enzymes that participate in the reduction have not been identified to date. The aim of this study was to confirm the role of human liver subcellular fractions in the metabolism of bupropion and elucidate the contribution of particular carbonyl-reducing enzymes. An HPLC method for the determination of bupropion metabolites was utilised. Bupropion is reduced to threohydrobupropion and less to erythrohydrobupropion in human liver cytosol, microsomes and also mitochondria. Surprisingly, intrinsic clearance for formation of both metabolites is the highest in mitochondrial fraction. Moreover this study provides the first direct evidence that 11β-hydroxysteroid dehydrogenase 1, AKR1C1, AKR1C2, AKR1C3 and CBR1 participate in the reducing biotransformation of bupropion in vitro. The enzyme kinetics of all of these reductases was investigated and kinetic parameters were calculated.

• MeSH
• alkoholoxidoreduktasy genetika   metabolismus   MeSH
• antidepresiva druhé generace metabolismus   MeSH
• biotransformace MeSH
• bupropion analogy a deriváty   metabolismus   MeSH
• cytosol enzymologie   MeSH
• hydroxysteroiddehydrogenasy genetika   metabolismus   MeSH
• jaterní mikrozomy enzymologie   MeSH
• jaterní mitochondrie enzymologie   MeSH
• játra enzymologie   MeSH
• kinetika MeSH
• lidé MeSH
• oxidace-redukce MeSH
• rekombinantní proteiny metabolismus   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

AKR1C3 is an important human enzyme that participates in the reduction of steroids and prostaglandins, which leads to proliferative signalling. In addition, this enzyme also participates in the biotransformation of xenobiotics, such as drugs and procarcinogens. AKR1C3 is involved in the development of both hormone-dependent and hormone-independent cancers and was recently demonstrated to confer cell resistance to anthracyclines. Because AKR1C3 is frequently upregulated in various cancers, this enzyme has been suggested as a therapeutic target for the treatment of these pathological conditions. In this study, nineteen isoquinoline alkaloids were examined for their ability to inhibit a recombinant AKR1C3 enzyme. As a result, stylopine was demonstrated to be the most potent inhibitor among the tested compounds and exhibited moderate selectivity towards AKR1C3. In the follow-up cellular studies, stylopine significantly inhibited the AKR1C3-mediated reduction of daunorubicin in intact cells without considerable cytotoxic effects. This inhibitor could therefore be used as a model AKR1C3 inhibitor in research or evaluated as a possible therapeutic anticancer drug. Furthermore, based on our results, stylopine can serve as a model compound for the design and future development of structurally related AKR1C3 inhibitors.

• MeSH
• 3-hydroxysteroid dehydrogenasy antagonisté a inhibitory   MeSH
• berberinové alkaloidy farmakologie   MeSH
• hydroxyprostaglandindehydrogenasy antagonisté a inhibitory   MeSH
• inhibitory enzymů farmakologie   MeSH
• kolorektální nádory farmakoterapie   enzymologie   patologie   MeSH
• lidé MeSH
• nádorové buňky kultivované MeSH
• nádory prsu farmakoterapie   enzymologie   patologie   MeSH
• proliferace buněk MeSH
• testosteron metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• western blotting MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

1. Nabumetone is a clinically used non-steroidal anti-inflammatory drug, its biotransformation includes major active metabolite 6-methoxy-2-naphtylacetic acid and another three phase I as well as corresponding phase II metabolites which are regarded as inactive. One important biotransformation pathway is carbonyl reduction, which leads to the phase I metabolite, reduced nabumetone. 2. The aim of this study is the determination of the role of a particular human liver subcellular fraction in the nabumetone reduction and the identification of participating carbonyl reducing enzymes along with their stereospecificities. 3. Both subcellular fractions take part in the carbonyl reduction of nabumetone and the reduction is at least in vitro the main biotransformation pathway. The activities of eight cytosolic carbonyl reducing enzymes--CBR1, CBR3, AKR1B1, AKR1B10, AKR1C1-4--toward nabumetone were tested. Except for CBR3, all tested reductases transform nabumetone to its reduced metabolite. AKR1C4 and AKR1C3 have the highest intrinsic clearances. 4. The stereospecificity of the majority of the tested enzymes is shifted to the production of an (+)-enantiomer of reduced nabumetone; only AKR1C1 and AKR1C4 produce predominantly an (-)-enantiomer. This project provides for the first time evidence that seven specific carbonyl reducing enzymes participate in nabumetone metabolism.

• MeSH
• alkoholoxidoreduktasy metabolismus   MeSH
• antiflogistika nesteroidní chemie   metabolismus   MeSH
• biokatalýza účinky léků   MeSH
• biotransformace účinky léků   MeSH
• butanony chemie   metabolismus   MeSH
• I. fáze biotransformace * MeSH
• játra účinky léků   enzymologie   MeSH
• kinetika MeSH
• lidé MeSH
• NADP farmakologie   MeSH
• stereoizomerie MeSH
• subcelulární frakce účinky léků   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Carbonyl-reducing enzymes are important in both metabolism of endogenous substances and biotransformation of xenobiotics. Because sufficient amounts of native enzymes must be obtained to study their roles in metabolism, an efficient purification strategy is very important. Oracin (6-[2-(2-hydroxyethyl)aminoethyl]-5,11-dioxo-5,6-dihydro-11H-indeno[1,2-c] isoquinoline) is a prospective anticancer drug and one of the xenobiotic substrates for carbonyl-reducing enzymes. A new purification strategy based on molecular recognition of carbonyl-reducing enzymes with oracin as a ligand is reported here. The type of covalent bond, ligand molecules orientation, and their distance from the backbone of the solid matrix for good stearic accessibility were taken into account during the designing of the carrier. The carriers based on magnetically active microparticles were tested by recombinant enzymes AKR1C3 and CBR1. The SiMAG-COOH magnetic microparticles with N-alkylated oracin and BAPA as spacer arm provide required parameters: proper selectivity and specificity enabling to isolate the target enzyme in sufficient quantity, purity, and activity.

• MeSH
• alkoholoxidoreduktasy izolace a purifikace   MeSH
• biotest MeSH
• chromatografie afinitní MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• enzymatické testy metody   MeSH
• enzymy izolace a purifikace   MeSH
• ethanolaminy chemie   MeSH
• isochinoliny chemie   MeSH
• ligandy MeSH
• magnetismus * MeSH
• mikrosféry MeSH
• molekulární struktura MeSH
• protinádorové látky chemie   MeSH
• Schiffovy báze chemie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The best known, most widely studied enzyme system in phase I biotransformation is cytochrome P450 (CYP), which participates in the metabolism of roughly 9 of 10 drugs in use today. The main biotransformation isoforms of CYP are associated with the membrane of the endoplasmatic reticulum (ER). Other enzymes that are also active in phase I biotransformation are carbonyl reducing enzymes. Much is known about the role of cytosolic forms of carbonyl reducing enzymes in the metabolism of xenobiotics, but their microsomal forms have been mostly poorly studied. The only well-known microsomal carbonyl reducing enzyme taking part in the biotransformation of xenobiotics is 11β-hydroxysteroid dehydrogenase 1, a member of the short-chain dehydrogenase/reductase superfamily. Physiological roles of microsomal carbonyl reducing enzymes are better known than their participation in the metabolism of xenobiotics. This review is a summary of the fragmentary information known about the roles of the microsomal forms. Besides 11β-hydroxysteroid dehydrogenase 1, it has been reported, so far, that retinol dehydrogenase 12 participates only in the detoxification of unsaturated aldehydes formed upon oxidative stress. Another promising group of microsomal biotransformation carbonyl reducing enzymes are some members of 17β-hydroxysteroid dehydrogenases. Generally, it is clear that this area is, overall, quite unexplored, but carbonyl reducing enzymes located in the ER have proven very interesting. The study of these enzymes could shed new light on the metabolism of several clinically used drugs or they could become an important target in connection with some diseases.

• MeSH
• 11-beta-hydroxysteroiddehydrogenasa typ 1 metabolismus   MeSH
• 17-hydroxysteroidní dehydrogenasy metabolismus   MeSH
• alkoholoxidoreduktasy metabolismus   MeSH
• biotransformace MeSH
• endoplazmatické retikulum enzymologie   MeSH
• katalýza MeSH
• kyseliny karboxylové chemie   MeSH
• lidé MeSH
• mikrozomy enzymologie   MeSH
• molekulární struktura MeSH
• oxidace-redukce MeSH
• substrátová specifita MeSH
• xenobiotika chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Tobacco smoking is the most widely known cause of human cancer-related death worldwide. NNK is one of the proved human carcinogens contributing to the development of several types of cancer. The carcinogenic effect of NNK depends on the metabolic pathway. Reduction of NNK by carbonyl reducing enzymes leads to the formation of NNAL. This pathway is generally regarded as detoxification pathway although the conditions and circumstances are quite complicated - the process depends on a formed enantiomer of NNAL. In this study a novel method for the determination of the metabolite NNAL was developed. This makes it possible to findand characterize carbonyl reducing enzymes that are involved in NNK metabolism. This simple HPLC method uses conventional HPLC instrumentation and is designed mainly for biochemical laboratories. A new microsomal carbonyl reducing enzyme participating in the metabolism of NNK in vitro has been described. Its activity was compared with other carbonyl reducing enzymes taking part in the biotransformation of NNK.

• MeSH
• alkoholoxidoreduktasy metabolismus   MeSH
• jaterní mikrozomy metabolismus   MeSH
• karcinogeny metabolismus   MeSH
• kouření škodlivé účinky   metabolismus   MeSH
• lidé MeSH
• nitrosaminy analýza   metabolismus   MeSH
• pyridiny analýza   MeSH
• stereoizomerie MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• abstrakty MeSH

Anthracyclines (ANTs) are widely used in the treatment of various forms of cancer. Although their usage contributes to an improvement in life expectancy, it is limited by severe adverse effects-acute and chronic cardiotoxicity. Several enzymes from both AKR and SDR superfamilies have been reported as participants in the reduction of ANTs. Nevertheless all of these are located in the cytosolic compartment. One microsomal reductase has been found to be involved in the metabolism of xenobiotics-11beta-HSD1, but no further information has been reported about its role in the metabolism of ANTs. The aim of this study is to bring new information about the biotransformation of doxorubicin (DOX), daunorubicin (DAUN) and idarubicin (IDA), not only in human liver microsomal fraction, but also by a novel human liver microsomal carbonyl reductase that has been purified by our group. The reduction of ANTs at C-13 position is regarded as the main pathway in the biotransformation of ANTs. However, our experiments with human liver microsomal fraction show different behaviour, especially when the concentration of ANTs in the incubation mixture is increased. Microsomal fraction was incubated with doxorubicin, daunorubicin and idarubicin. DOX was both reduced into doxorubicinol (DOXOL) and hydrolyzed into aglycone DOX and then subsequently reduced. The same behaviour was observed for the metabolism of DAUN and IDA. The activity of hydrolases definitely brings a new look to the entire metabolism of ANTs in microsomal fraction, as formed aglycones undergo reduction and compete for the binding site with the main ANTs. Moreover, as there are two competitive reducing reactions present for all three ANTs, kinetic values of direct reduction and the reduction of aglycone were calculated. These results were compared to previously published data for human liver cytosol. In addition, the participation of the newly determined human liver microsomal carbonyl reductase was studied. No reduction of DOX into DOXOL was detected. Nevertheless, the involvement in reduction of DAUN into DAUNOL as well as IDA into IDAOL was demonstrated. The kinetic values obtained were then compared with data which have already been reported for cytosolic ANTs reductases.

• MeSH
• alkoholoxidoreduktasy metabolismus   MeSH
• antracykliny metabolismus   MeSH
• biotransformace MeSH
• buněčná membrána enzymologie   metabolismus   MeSH
• jaterní mikrozomy enzymologie   metabolismus   MeSH
• lidé MeSH
• protinádorové látky metabolismus   MeSH
• substrátová specifita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH