Reductase

WWOX is a proapoptotic protein and a tumor suppressor protein. WWOX is found in all eukaryotes and involved in the regulation of a broad range of cellular functions such as protein degradation, transcription, and RNA splicing. WWOX functions synergistically with TP53/p53 to control genotoxic stress-induced cell death. WWOX takes part in tumor necrosis factor (TNF)-mediated cell death. Loss of WWOX expression is associated with pancreatobiliary cancers. Reduced expression levels of WWOX protein is associated with the pathogenesis of basal-like differentiation in breast cancer. Loss of WWOX expression is associated with extrahepatic cholangiocarcinoma. WWOX gene alteration is an early genetic alteration contributes to oral carcinogenesis. WWOX induces apoptosis and inhibits human hepatocellular carcinoma cell growth through a mechanism enhanced by JNK inhibition.

MECR catalyzes the reduction of trans-2-enoyl-CoA to acyl-CoA with chain length from C6 to C16 in an NADPH dependent manner with preference to medium chain length substrate. MECR protein takes part in the mitochondrial synthesis of fatty acids.

QDPR belongs to the short-chain dehydrogenases/reductase (SDR) family of enzymes. Operating as a homodimer, QDPR has an imperative role in the recycling of tetrahydrobiopterin (BH4), a vital cofactor for the hydroxylation of the aromatic amino acids (tryptophan, tyrosine and phenylalanine). More precisely, QDPR catalyzes the regeneration of BH4 from quinonoid dihydrobiopterin (qBH2), the product generated from the hydroxylation reactions. Mutations in the QDPR gene may lead to phenylketonuria II.

Pyrroline-5-Carboxylate Reductase Like (PYCRL) is a member of the pyrroline-5-carboxylate reductase family and acts as a homodecamer. PYCRL plays a key role in proline bio-synthesis. Proline serves as a non-enzymatic antioxidant to reduce damage caused by reactive oxygen species (ROS) in microorganisms, animals and plants. In the final stage of proline biosynthesis, PYCRL catalyzes the reduction of aldehyde dehydrogenase 4A1 (ALDH4A1) to proline with NAD(P)H as the cofactor.

Pyrroline-5-carboxylate reductase 2 isoform 1 (PYCR2) is a member of the pyrroline-5-carboxylate reductase family. PYCR2 protein catalyzes the conversion of pyrroline-5-carboxylate to proline, which is the last step in proline biosynthesis. The three substrates of the PYCR2 enzyme are L-proline, NAD+, and NADP+, while its four products are 1-pyrroline-5-carboxylate, NADH, NADPH, and H+.

PYCR1 is a universal housekeeping enzyme which catalyzes the NAD(P)H-dependent conversion of pyrroline-5-carboxylate to proline. PYCR1 enzyme also takes a physiologic part in the generation of NADP(+) in certain cell types. PYCR1 forms a homopolymer and localizes to the mitochondrion. Mutations in PYCR1 are the source of cutis laxa autosomal recessive type 2B (ARCL2B).

Prostaglandin Reductase 2 (PTGR2) is a member of the medium-chain dehydrogenase/reductase superfamily. PTGR2 is an enzyme involved in the metabolism of prostaglandins. PTGR2 catalyzes an NADPH-dependent reduction of the conjugated alpha, beta-unsaturated double bond of 15-keto-PGE(2), which is a fundamental step in terminal inactivation of prostaglandins and suppression of PPARgamma-mediated adipocyte differentiation. PTGR2 may also be involved in controlling activation of the peroxisome proliferator-activated receptor.

Glutathione reductase (GSR) belongs to the class-I pyridine nucleotide-disulfide oxidoreductase family. The GSR enzyme is a homodimeric flavoprotein and has a role in maintaining glutathione (GSH) in its reduced form by catalyzing the reduction of glutathione disulfide (GSSG): GSSG + NADPH + H+ ->2GSH + NADP+. In the majority of eukaryotic cells, GSR upholds the ratio of [GSH] / [GSSG], and partakes in quite a few critical functions such as the detoxification of reactive oxygen species as well as protein and DNA biosynthesis.

Prostaglandin Reductase 1 (PTGR1) is a member of the NADP-dependent oxidoreductase L4BD family. PTGR1 catalyzes the conversion of leukotriene B4 into its biologically less active metabolite, 12-oxo-leukotriene B4, thus being a primary step of metabolic inactivation of leukotriene B4. PTGR1 is highly expressed in the kidney, liver, and intestine but not in leukocytes.

GRHPR located in the cytosol, belongs to the D-isomer specific 2-hydroxyacid dehydrogenase family of proteins. GRHPR is widely expressed in liver. GRHPR has widespread tissue expression and is involved in metabolism. GRHPR is an enzyme with hydroxypyruvate reductase, glyoxylate reductase, and D-glycerate dehydrogenase enzymatic activities.

Glutathione reductase (Gor) is a member of the class-I pyridine nucleotide disulfide oxidoreductase family. The main role of the Gor protein is to uphold high levels of reduced glutathione in the cytosol. With the associated oxidation of NADPH, Gor transforms oxidized glutathione to the reduced form. The active site of the Gor protein is a redox-active disulfide bond.

GMPR2 is the single known metabolic step by which guanine nucleotides can be transformed to the pivotal precursor of both adenine and guanine nucleotides. GMPR2 catalyzes the permanent NADPH-dependent reductive deamination of GMP to IMP, and is involved in re-utilization of free intracellular bases and purine nucleosides.

Guanosine monophosphate reductase (GMPR) catalyzes the irreversible NADPH-dependent deamination of GMP to IMP. GMPR acts in the conversion of nucleobase, nucleoside and nucleotide derivatives of G to A nucleotides, and in upholding the intracellular balance of A and G nucleotides. In addition, the GMPR protein functions in the re-utilization of free intracellular bases and purine nucleosides.

Thioredoxin Reductase 3 Neighbor, also known as TXNRD3NB is expressed in pancreas, esophagus, bone marrow and keratinocytes. TXNRD3NB shares overlapping exons with TXNRD3. In addition the initiation codon is found in exon 3 of the TXNRD3IT1 gene.

TXNRD1 belongs to the selenium-containing pyridine nucleotide-disulphide oxidoreductase family, which has a conserved catalytic site of Cys-Val-Asn-Val-Gly-Cys. TXNRD1 decreases thioredoxins as well as other substrates, and participates in selenium metabolism and protection against oxidative stress. Inhibition of TXNRD1 activity serves as a potential treatment for cancer, AIDS and other autoimmune diseases as well as bacterial infections and parasitic diseases.

TXNRD1 belongs to the selenium-containing pyridine nucleotide-disulphide oxidoreductase family, which has a conserved catalytic site of Cys-Val-Asn-Val-Gly-Cys. TXNRD1 decreases thioredoxins as well as other substrates, and participates in selenium metabolism and protection against oxidative stress. Inhibition of TXNRD1 activity serves as a potential treatment for cancer, AIDS and other autoimmune diseases as well as bacterial infections and parasitic diseases.

Thioredoxin reductase (TrxR/NTR), an enzyme belonging to the flavoprotein family of pyridine nucleotide-disulfide oxidoreductases. Thioredoxin reductase (TrxR), a component of the thioredoxin system, including thioredoxin (Trx) and NADPH, catalyzes the transfer of electrons from NADPH to Trx, acts as a reductant of disulfide-containing proteins and participates in the defense system against oxidative stresses.

TRXR is a ubiquitous enzyme which participates in various cellular processes such as cell growth, p53 activity, and protection against oxidation stress. The mammalian Thioredoxin reductase cleaves thioredoxins as well as non-disulfide substrates such as selenite, lipoic acids, lipid hydroperoxides, and hydrogen peroxidec.

TP53I3 participates in the generation of reactive oxygen species (ROS). TP53I3 has low NADPH-dependent naphtoquinone reductase activity, with a preference for 1,2-naphtoquinone over 1,4-naphtoquinone. TP53I3 has low NADPH-dependent diamine reductase activity (in vitro). TP53I3 is localized to the cytoplasm and induced in primary, non-transformed and transformed cell cultures after exposure to genotoxic agents. TP53I3 microsatellite polymorphism is associated with differential susceptibility to cancer.

3-ketodihydrosphingosine reductase (KDSR) is a 332 amino acid multi-pass membrane protein which localizes to the ER and is a member of the short-chain dehydrogenases/reductases (SDR) family. KDSR is a secreted protein that is weakly expressed in hematopoietic tissue. Furthermore, KDSR catalyzes the reduction of 3-ketodihydrosphingosine (KDS) to dihydrosphingosine (DHS). The putative active site residues of KDSR are found on the cytosolic side of the endoplasmic reticulum membrane. Chromosomal rearrangement in the KDSR gene is a cause of follicular lymphoma, aka type II chronic lymphatic leukemia.

CBR4 is a member of the short-chain dehydrogenase/reductase family. CBR4 has a role in biosynthesis of fatty acids in the mitochondria and a broad substrate specificity and reduces 9,10-phenanthrenequinone, 1,4-benzoquinone and a range of other o-quinones and p-quinones (in vitro). CBR4 formation of a heteroteramer with HSD17B8 has NADH-dependent 3-ketoacyl-acyl carrier protein reductase activity for o- and p-quinones.

CBR3 catalyzes the reduction of a large number of biologically and pharmacologically active carbonyl compounds to their corresponding alcohols. CBR3 is one of several monomeric NADPH-dependent oxidoreductases. Furthermore, CBR3 contains 3 exons spanning 11.2 kilobases and is strongly linked to another carbonyl reductase gene, the CBR1. It was suggested that CBR3 mediates 9-cis-retinoic acid-induced cytostatis and is a potential prognostic marker for oral malignancy.
CBR3 is identified in the ovary, pancreas, intestine, colon, kidney, brain, thymus, lung, heart, liver, spleen, leukocyte, prostate and the testis.

CBR1 is one of numerous monomeric, NADPH-dependent oxidoreductases having ubiquistly specificity for carbonyl compounds. CBR1 is broadly distributed in human tissues. CBR1 metabolizes toxic environmental quinones and pharmacological relevant substrates. CBR1 converts prostaglandin E2 to prostaglandin F2-alpha.

PECR is the main enzyme for a projected peroxisomal chain elongation pathway and is primarily expressed in kidney and liver.

BLVRB (EC 1.3.1.24) catalyzes electron transfer from reduced pyridine nucleotides to flavins as well as methylene blue, pyrroloquinoline quinone, riboflavin, or methemoglobin. BLVRB is involved in protecting cells from oxidative damage or in regulating iron metabolism. BLVRB converts biliverdin to bilirubin in the liver, converting a double-bond between the second and third pyrrole ring into a single-bond. BLVRB plays a role as in human erythrocytic heme catabolic pathway and most mammalian species. Biliverdin reductase is abundantly expressed in kidney, spleen, liver and brain as well as at lower levels in the thymus and minimal levels being detected in testis.

BLVRB (EC 1.3.1.24) catalyzes electron transfer from reduced pyridine nucleotides to flavins as well as methylene blue, pyrroloquinoline quinone, riboflavin, or methemoglobin. BLVRB is involved in protecting cells from oxidative damage or in regulating iron metabolism. BLVRB converts biliverdin to bilirubin in the liver, converting a double-bond between the second and third pyrrole ring into a single-bond. BLVRB plays a role as in human erythrocytic heme catabolic pathway and most mammalian species. Biliverdin reductase is abundantly expressed in kidney, spleen, liver and brain as well as at lower levels in the thymus and minimal levels being detected in testis.

Biliverdin reductase A (BLVRA) is a member of the gfo/idh/mocA family. BLVRA is an enzyme that converts biliverdin to bilirubin, converting a double-bond between the second and third pyrrole ring into a single-bond. BLVRA reduces the gamma-methene bridge of the open tetrapyrrole, biliverdin IX alpha, to bilirubin with the simultaneous oxidation of a NADH or NADPH cofactor (Bilirubin + NAD(P)+ = biliverdin + NAD(P)H ).
BLVRA is a regulator for induction of activating transcription factor-2 and heme oxygenase-1. Furthermore, BLVRA enhances the role of HO-1 in cytoprotection and provides cytoprotection independent of heme degradation. In addition, Bilirubin while acting as a cytoprotective antioxidant is itself oxidized to biliverdin and subsequently recycled by biliverdin reductase back to bilirubin.

Sepiapterin Reductase is an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is essential in the biosynthesis of BH4. Mutations in Sepiapterin Reductase gene result in DOPA-responsive dystonia due to sepiaterin reductase deficiency defined by the presence of sustained involuntary muscle contractions, often leading to abnormal postures. Sepiapterin reductase is part of the short-chain dehydrogenase/reductase family which reduces exogenous carbonyl compounds as well as phenylpropanedione. Sepiapterin reductase is an important enzyme for the biosynthesis of tetrahydrobiopterin, an necessary cofactor for aromatic amino acid hydrolases together with tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis.

Sepiapterin Reductase is an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is essential in the biosynthesis of BH4. Mutations in Sepiapterin Reductase gene result in DOPA-responsive dystonia due to sepiaterin reductase deficiency defined by the presence of sustained involuntary muscle contractions, often leading to abnormal postures. Sepiapterin reductase is part of the short-chain dehydrogenase/reductase family which reduces exogenous carbonyl compounds as well as phenylpropanedione. Sepiapterin reductase is an important enzyme for the biosynthesis of tetrahydrobiopterin, an necessary cofactor for aromatic amino acid hydrolases together with tyrosine hydroxylase, the rate-limiting enzyme in DOPA synthesis.

NFNB demonstrates the capability to reduce quinines. NFNB enzyme activates prodrugs in antibody directed enzyme prodrug therapy. NFNB reduces nitrofurazone, quinones and anti-tumor agent CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide). The reduction of CB1954 results in the generation of cytotoxic species.

Disulfide Oxidoreductase or DsbA is a protein, found in the plasma. It is part of the thioredoxin protein family. The protein creates disulfide bonds in the target proteins by contributing disulfide bond from its Cys30-Pro31-His32-Cys33 active site to a couple of cysteine residues.

DsbA appears to be necessary for correct formulation of disulfide bonds in exported proteins in vivo. DsbA is useful as a standard in immunoblotting. This protein catalyses the reduction and exchange of disulfide bonds and the oxidation of free sulfhydryl groups in vitro. It is the strongest oxidant of the thioredoxin superfamily. This thio/disulfide oxidoreductase is required for efficient disulfide bond formation in the periplasm of E. coli.

Dehydrogenase/reductase SDR family member 9 (DHRS9) functions as a homotetramer, which converts both 3-alpha-tetrahydroprogesterone (allopregnanolone) and 3-alpha-androstanediol to dihydroxyprogesterone and is believed to have a part in retinoic acid biosynthesis.

Dehydrogenase/reductase SDR family member 4 (DHRS4) is a member of the short-chain dehydrogenases/reductases (SDR) family. DHRS4 reduces all trans retinal and 9-cis retinal. In addition, the DHRS4 protein can catalyze the oxidation of all trans retinol with NADP as cofactor, but with a much lower efficiency. Furthermore, DHRS4 reduces alkyl phenyl ketones and alpha dicarbonyl compounds with aromatic rings, such as pyrimidine 4 aldehyde, 3 benzoylpyridine, 4 benzoylpyridine, menadione and 4 hexanoylpyridine.

Dihydrofolate reductase (DHFR) is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, with NADPH as electron donor that can be converted to the kinds of tetrahydrofolate cofactors applied in 1-carbon transfer chemistry. DHFR converts dihydrofolate into tetrahydrofolate, which is a methyl group shuttle required for the de novo synthesis of purines, thymidylic acid, and specific amino acids. Even though the functional DHFR gene is mapped to chromosome 5, numerous intronless processed pseudogenes or dihydrofolate reductase-like genes are identified on separate chromosomes. DHFR deficiency is associated with megaloblastic anemia. DHFR knockdown plays a role in the anticancer activity of 2-hydroxyoleic acid. DHFR gene insertion/deletion polymorphism is linked to variation in serum and red blood cell folate concentrations in women.

Dihydrofolate reductase (DHFR) is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, with NADPH as electron donor that can be converted to the kinds of tetrahydrofolate cofactors applied in 1-carbon transfer chemistry. DHFR converts dihydrofolate into tetrahydrofolate, which is a methyl group shuttle required for the de novo synthesis of purines, thymidylic acid, and specific amino acids. Even though the functional DHFR gene is mapped to chromosome 5, numerous intronless processed pseudogenes or dihydrofolate reductase-like genes are identified on separate chromosomes.
DHFR deficiency is associated with megaloblastic anemia.
DHFR knockdown plays a role in the anticancer activity of 2-hydroxyoleic acid.
DHFR gene insertion/deletion polymorphism is linked to variation in serum and red blood cell folate concentrations in women.

Peroxisomal 2,4-dienoyl-CoA reductase (DECR2) is an supporting enzyme of beta-oxidation. DECR2 partakes in the degradation of unsaturated fatty enoyl-CoA esters having double bonds in both even- and odd-numbered positions in peroxisome. DECR2 catalyzes the NADP-dependent reduction of 2,4-dienoyl-CoA to yield trans-3-enoyl-CoA.

DECR1 is a mitochondrial protein which exists as a homotetramer and is a member of a family of short-chain dehydrogenases/reductases. DECR1 acts as an auxiliary enzyme of beta-oxidation andt partakes in the metabolism of unsaturated fatty enoyl-CoA esters. in particular, DECR1 uses NADP+ to catalyze the reduction of 2,4-dienoyl-CoA to yield trans-3-enoyl-CoA that can subsequently be used as an intermediate in the Krebs cycle. Furthermore, DECR1 is believed to work as a tumor suppressor, possibly downregulating the expression of Neu and slowing the rate of tumorigenesis.

DCXR catalyzes the NADPH-dependent reduction of numerous pentoses, tetroses, trioses, alpha-dicarbonyl molecules and L-xylulose. DCXR takes part in the uronate cycle of glucose metabolism. DCXR participates in the water absorption and cellular osmoregulation in the proximal renal tubules by producing xylitol, an osmolyte, thus preventing osmolytic stress from occurring in the renal tubules.

DCXR catalyzes the NADPH-dependent reduction of numerous pentoses, tetroses, trioses, alpha-dicarbonyl molecules and L-xylulose. DCXR takes part in the uronate cycle of glucose metabolism. DCXR participates in the water absorption and cellular osmoregulation in the proximal renal tubules by producing xylitol, an osmolyte, thus preventing osmolytic stress from occurring in the renal tubules.

Aldo-Keto Reductase Family 7 Member A3 or AKR7A3, is an enzyme, it is part of the detoxification of aldehydes and ketones process. AKR7A3 diminishes the dialdehyde protein-binding form of aflatoxin B1 to the non-binding AFB1 dialcohol. The enzyme takes partin protection of liver from toxic and carcinogenic effects of AFB1, a potent hepatocarcinogen.

AKR7A3, takes part in the detoxification of aldehydes and ketones. AKR7A3 reduces the dialdehyde protein-binding form of aflatoxin B1 (AFB1) to the non-binding AFB1 dialcohol. AKR7A3 participates in protection of liver against the toxic and carcinogenic effects of AFB1, a potent hepatocarcinogen.

AKR7A2 participates in the detoxification of aldehydes and ketones. AKR7A2 catalyzes the NADPH-dependent reduction of succinic semialdehyde to gamma-hydroxybutyrate. AKR7A2 is involved in producing the neuromodulator gamma-hydroxybutyrate (GHB). AKR7A2 has extensive substrate specificity. AKR7A2 shows NADPH-dependent aldehyde reductase activity towards 2-carboxybenzaldehyde, 2-nitrobenzaldehyde and pyridine-2-aldehyde (in vitro). AKR7A2 reduces 1,2-naphthoquinone and 9,10-phenanthrenequinone (in vitro). AKR7A2 reduces the dialdehyde protein-binding form of aflatoxin B1 (AFB1) to the non-binding AFB1 dialcohol. AKR7A2 takes part in protection of liver against the toxic and carcinogenic effects of AFB1, a potent hepatocarcinogen.

Methionine sulfoxide reductase B3 (MSRB3) is a member of the methionine sulfoxide reductases (MSR) family proteins. MSRB3 catalyzes the reduction of methionine sulfoxide to methionine. The MSRB3 enzyme acts as a monomer and requires zinc as a cofactor. MSRs are thought to defend against reactive oxygen species-induced oxidative damage in various organs, including the most environmentally exposed organ, the human skin. MSRB3 has a vital role in cold tolerance by eliminating MetO and ROS which accumulate at the ER during cold acclimation.

Aldo-keto reductase family 1 member D1 (AKR1D1) belongs to the AKR superfamily. The AKR family proteins are soluble NADPH oxidoreductases, which have vital roles in the metabolism of drugs, carcinogens and reactive aldehydes. AKR1D1 is also responsible for the catalysis of the 5-beta-reduction of bile acid intermediates and steroid hormones that carry a delta (4)-3-1 structure. AKR1D1 is highly expressed in the liver, colon and testis. Deficiency of the AKR1D1 enzyme may contribute to hepatic dysfunction.

MSRB2 is a member of the methionine sulfoxide reductases(MSRs) family which are antioxidant repair enzymes. MSRB2 protein catalyzes the decrease of free and protein-bound methionine sulfoxide to methionine. MSRB2 has a part in protecting against oxidative stress in numerous organs.

Aldo-keto reductase family 1 member D1 (AKR1D1) belongs to the AKR superfamily. The AKR family proteins are soluble NADPH oxidoreductases, which have vital roles in the metabolism of drugs, carcinogens and reactive aldehydes. AKR1D1 is also responsible for the catalysis of the 5-beta-reduction of bile acid intermediates and steroid hormones that carry a delta (4)-3-1 structure. AKR1D1 is highly expressed in the liver, colon and testis. Deficiency of the AKR1D1 enzyme may contribute to hepatic dysfunction.

Methionine sulfoxide reductase B (MsrB) from Escherichia coli is a member of the msrB Met sulfoxide reductase family. The E.coli msrB carries out the reduction of methionine-R-sulfoxide to methionine. msrB possess a metal binding site composed of 2 CXXC motifs. The bound metal (zinc or iron) may stabilize the conformation of the enzymes.

Methionine sulfoxide reductase A (MSRA) is a member of the MsrA Met sulfoxide reductase family. The MSRA enzyme has a vital function as a repair enzyme for proteins which have been inactivated by oxidation. MSRA catalyzes the reversible oxidation-reduction of methionine sulfoxide in proteins to methionine. The three substrates of the MSRA enzyme are peptide-L-methionine, thioredoxin disulfide, and H2O, while its 2 products are peptide-L-methionine (R)-S-oxide and thioredoxin. The MSRA protein is ubiquitous and extremely conserved. Human and animal studies have shown the ultimate levels of expression in kidney and nervous tissue.

AKR1C4 is a member of the aldo/keto reductase superfamily that has over 40 known enzymes and proteins. AKR1C4 enables the conversion of aldehydes and ketones to their corresponding alcohols by using NADH and/or NADPH as cofactors. AKR1C4 takes part in the bioreduction of chlordecone, a toxic organochlorine pesticide, to chlordecone alcohol in liver.