Steroid Metabolism, Inborn Errors
46, XX Disorders of Sex Development
11-beta-Hydroxysteroid Dehydrogenase Type 1
Hydroxymethylglutaryl CoA Reductases
11-beta-Hydroxysteroid Dehydrogenase Type 2
Isoleucine-15 of rainbow trout carbonyl reductase-like 20beta-hydroxysteroid dehydrogenase is critical for coenzyme (NADPH) binding. (1/27)Carbonyl reductase-like 20beta-hydroxysteroid dehydrogenase (CR/20beta-HSD) is an enzyme that converts 17alpha-hydroxyprogesterone to 17alpha, 20beta-dihydroxy-4-pregnen-3-one (the maturation-inducing hormone of salmonid fish). We have previously isolated two types of CR/20beta-HSD cDNAs from ovarian follicle of rainbow trout (Oncorhynchus mykiss). Recombinant proteins produced by expression in Escherichia coli in vitro showed that one (type A) had CR and 20beta-HSD activity but that the other (type B) did not. Among the three distinct residues between the protein products encoded by the two cDNAs, two residues (positions 15 and 27) are located in the N-terminal Rossmann fold, the coenzyme binding site. To investigate the structure/function relationships of CR/20beta-HSDs, we generated mutants by site-directed mutagenesis at the following positions: MutA/I15T, MutB/T15I, and MutB/Q27K. Enzyme activity of wild-type A was abolished by substitution of Ile-15 by Thr (MutA/I15T). Conversely, enzyme activity was acquired by the replacement of Thr-15 with Ile in type B (MutB/T15I). MutB/T15I mutant showed properties similar to the wild-type A in every aspect tested. Mutation MutB/Q27K had only partial enzyme activity, indicating that Ile-15 plays an important role in enzyme binding of cofactor NADPH. (+info)
Affinity labeling of steroid binding sites. Study of the active site of 20beta-hydroxysteroid dehydrogenase with 2alpha-bromoacetoxyprogesterone and 11alpha-bromacetoxyprogesterone. (2/27)To further characterize the active site of 20beta-hydroxysteroid dehydrogenase (EC 220.127.116.11) from Streptomyced hydrogenans we synthesized 2alpha-bromoacetoxyprogesterone, a substrate for the enzyme in 0.05 M phosphate buffer at 25 degrees, pH 7.0, with Km and Vmax values of 1.90 X 10(-5) M and 6.09 nmol/min/mg of enzyme, respectively. This affinity labeling steroid inactivates 20beta-hydroxysteroid dehydrogenase in an irreversible and time-dependent manner which follows pseudo-first order kinetics with a t1/2 value of 4.6 hours. 2alpha-[2-3H]Bromoacetoxyprogesterone was synthesized and used to radiolabel the enzyme active site. Amino acid analysis of the acid hydrolysate of the radiolabeled enzyme supports a mechanism whereby the steroid moiety delivers the alkylating group to the steroid binding site of the enzyme where it reacts with a methionyl residue. Both 2alpha- and 11alpha-bromoacetoxyprogesterone alkylate a methionyl residue at the active site of 20beta-hydroxysteroid dehydrogenase. The enzyme was inactivated with a mixture containing both 2alpha-[2-3H]Bromoacetoxyprogesterone and 11alpha-2[2-14C]bromoacetoxyprogesterone. Following degradation of separate aliquots of the radiolabeled enzyme by cyanogen bromide or trypsin, the protein fragments were separated by gel filtration and ion exchange chromatography. Resolution of peptides carrying the 3H label from those possessing the 14C label demonstrates that 2alpha-bromoacetoxyprogesterone and 11alpha-bromoacetoxyprogesterone each label a different methionine at the steroid binding site of 20beta-hydroxysteroid dehydrogenase. (+info)
Teleost ovarian carbonyl reductase-like 20beta-hydroxysteroid dehydrogenase: potential role in the production of maturation-inducing hormone during final oocyte maturation. (3/27)17alpha,20beta-Dihydroxy-4-pregnen-3-one is the major oocyte maturation-inducing hormone of several teleost species. Gonadotropin-induced increase in ovarian 20beta-hydroxysteroid dehydrogenase activity is essential for the synthesis of maturation-inducing hormone. Cloning and expression studies suggest that ayu (Plecoglossus altivelis) ovarian carbonyl reductase can function as 20beta-hydroxysteroid dehydrogenase. The amino acid sequence deduced from the isolated cDNA had 276 amino acid residues and shared approximately 60% homology with mammalian and teleostean carbonyl reductases. The sequence data search showed that the ayu cDNA clone belongs to the short-chain dehydrogenase/reductase family. The clear lysate prepared from Escherichia coli harboring the cDNA catalyzed the production of maturation-inducing hormone. Its identification was confirmed by two-dimensional, thin-layer chromatography followed by recrystallization. Purification of the E. coli-expressed cDNA product revealed that it possessed both carbonyl reductase and steroid dehydrogenase activities, and 17alpha-hydroxyprogesterone, the endogenous immediate precursor of maturation-inducing hormone, was one of the preferred substrates. Furthermore, Northern blot analysis denoted that the transcripts are present both in fully grown, immature ovarian follicles and at higher levels in mature ovarian follicles. These results demonstrate that the carbonyl reductase of ayu ovary is involved in the production of maturation-inducing hormone, and they provide evidence for a novel physiological role of this enzyme in the final maturation of oocytes. Based on its functional properties, the enzyme can be referred to as carbonyl reductase-like 20beta-hydroxysteroid dehydrogenase. (+info)
Ovarian carbonyl reductase-like 20beta-hydroxysteroid dehydrogenase shows distinct surge in messenger RNA expression during natural and gonadotropin-induced meiotic maturation in nile tilapia. (4/27)Meiotic maturation in fish is accomplished by maturation-inducing hormones. 17alpha,20beta-Dihydroxy-4-pregnen-3-one (17alpha,20beta-DP) was identified as the maturation-inducing hormone of several teleosts, including Nile tilapia. A cDNA encoding 20beta-hydroxysteroid dehydrogenase (20beta-HSD), the enzyme that converts 17alpha-hydroxyprogesterone to 17alpha,20beta-DP, was cloned from the ovarian follicle of Nile tilapia. Genomic Southern analysis indicated that 20beta-HSD probably exists as a single copy in the genome. The Escherichia coli-expressed cDNA product oxidized both carbonyl and steroid compounds, including progestogens, in the presence of NADPH. Carbonyl reductase-like 20beta-HSD is broadly expressed in various tissues of tilapia, including ovary, testis, and gill. Northern blot and reverse transcription polymerase chain reaction analyses during the 14-day spawning cycle revealed that the expression of 20beta-HSD in ovarian follicles is low from Day 0 to Day 8 after spawning and is not detectable on Day 11. Distinct expression was evident at Day 14, the day of spawning. In males, 20beta-HSD expression was observed continually in mature testes but not in immature testes of 30-day-old fish. In vitro incubation of postvitellogenic immature follicles (corresponding to Day 11 after spawning) with hCG induced the expression of 20beta-HSD mRNA transcripts within 1-2 h, followed by the final meiotic maturation of oocytes. In tissues such as gill, muscle, brain, and pituitary, however, hCG treatment did not induce any changes in the levels of mRNA transcripts. Actinomycin D blockade of hCG-induced 20beta-HSD expression and final oocyte maturation demonstrated the involvement of transcriptional factors. The carbonyl reductase-like 20beta-HSD plays an important role in the meiotic maturation of tilapia gametes. (+info)
An aldose reductase with 20 alpha-hydroxysteroid dehydrogenase activity is most likely the enzyme responsible for the production of prostaglandin f2 alpha in the bovine endometrium. (5/27)Prostaglandins are important regulators of reproductive function. In particular, prostaglandin F2 alpha (PGF(2 alpha)) is involved in labor and is the functional mediator of luteolysis to initiate a new estrous cycle in many species. These actions have been extensively studied in ruminants, but the enzymes involved are not clearly identified. Our objective was to identify which prostaglandin F synthase is involved and to study its regulation in the endometrium and in endometrial primary cell cultures. The expression of all previously known prostaglandin F synthases (PGFSs), two newly discovered PGFS-like genes, and a 20 alpha-hydroxysteroid dehydrogenase was studied by Northern blot and reverse transcription PCR. These analyses revealed that none of the known PGFS or the PGFS-like genes were significantly expressed in the endometrium. On the other hand, the 20 alpha-hydroxysteroid dehydrogenase gene was strongly expressed in the endometrium at the time of luteolysis. The corresponding recombinant enzyme has a K(m) of 7 microM for PGH(2) and a PGFS activity higher than the lung PGFS. This enzyme has two different activities with the ability to terminate the estrous cycle; it metabolizes progesterone and synthesizes PGF(2 alpha). Taken together, these data point to this newly identified enzyme as the functional endometrial PGFS. (+info)
Pig testicular 20 beta-hydroxysteroid dehydrogenase exhibits carbonyl reductase-like structure and activity. cDNA cloning of pig testicular 20 beta-hydroxysteroid dehydrogenase. (6/27)cDNA inserts encoding 20 beta-hydroxysteroid dehydrogenase (EC 18.104.22.168) were, for the first time, isolated and cloned from a pig testis cDNA library using synthetic oligonucleotides deduced from the partially determined amino acid sequences. The cDNA contains an open reading frame predicted to encode 289 amino acid residues. Surprisingly, it has 85% amino acid homology to human carbonyl reductase. The purified enzyme exhibited carbonyl reductase activity. Adenine-rich sequence was located in the 3'-untranslated nine-rich sequence was located in the 3'-untranslated region, which may mean that the gene originates by retroposition. RNA transcripts of 1.3, 3, and 6 kilobases were detected in poly(A)+ RNA extracted from pig testis by Northern blot hybridization. The steady-state level of the RNA species increased to a maximum in testes from 10-day-old pigs, but rapidly declined thereafter to the same levels found in testes of mature animals. (+info)
Short-chain dehydrogenases. Proteolysis and chemical modification of prokaryotic 3 alpha/20 beta-hydroxysteroid, insect alcohol and human 15-hydroxyprostaglandin dehydrogenases. (7/27)Prokaryotic 3 alpha/20 beta-hydroxysteroid dehydrogenase exhibits one segment sensitive to proteolysis with Glu-C protease and trypsin (cleaving after Glu192 and Arg196, respectively). Cleavage is associated with dehydrogenase inactivation; the presence of NADH offers almost complete protection and substrate (cortisone) gives some protection. Distantly related insect alcohol dehydrogenase is more resistant to proteolysis, but cleavage in a corresponding segment is detectable with Asp-N protease (cleaving before Asp198), while a second site (at Glu243) is sensitive to cleavage with both Glu-C and Asp-N proteases. Combined, the results suggest the presence of limited regions especially sensitive to proteolysis and the possibility of some association between the enzyme active site and the sensitive site(s). Modification of the hydroxysteroid dehydrogenase with tetranitromethane is paralleled by enzyme inactivation. With a 10-fold excess of reagent, labeling corresponds to 1.2 nmol Tyr/nmol protein chain and is recovered largely in Tyr152, with lesser amounts in Tyr251. Tetranitromethane also rapidly inhibits the other two dehydrogenases, but they contain Cys residues, preventing direct correlation with Tyr modification. Together, the proteolysis and chemical modifications highlight three segments of short-chain dehydrogenase subunits, one mid-chain, containing Tyr152 of the steroid dehydrogenase (similar numbers in the other enzymes), strictly conserved and apparently close to the enzyme active site, the other around position 195, sensitive to proteolysis and affected by coenzyme binding, while the third is close to the C-terminus. (+info)
Cooperativity between 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase in the lumen of the endoplasmic reticulum. (8/27)The functional coupling of 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase was investigated in rat liver microsomal vesicles. The activity of both enzymes was latent in intact vesicles, indicating the intraluminal localization of their active sites. Glucose-6-phosphate, a substrate for hexose-6-phosphate dehydrogenase, stimulated the cortisone reductase activity of 11beta-hydroxysteroid dehydrogenase type 1. Inhibition of glucose-6-phosphate uptake by S3483, a specific inhibitor of the microsomal glucose-6-phosphate transporter, decreased this effect. Similarly, cortisone increased the intravesicular accumulation of radioactivity upon the addition of radiolabeled glucose-6-phosphate, indicating the stimulation of hexose-6-phosphate dehydrogenase activity. A correlation was shown between glucose-6-phosphate-dependent cortisone reduction and cortisone-dependent glucose-6-phosphate oxidation. The results demonstrate a close cooperation of the enzymes based on co-localization and the mutual generation of cofactors for each other. (+info)
Cortisone reductase is an enzyme that plays a role in the metabolism of cortisone, a hormone produced by the adrenal glands. It is also known as 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) and is primarily found in the liver, adipose tissue, and the brain. The primary function of cortisone reductase is to convert cortisone to its active form, cortisol. Cortisol is a glucocorticoid hormone that plays a crucial role in regulating metabolism, immune function, and stress response. Cortisone reductase also plays a role in regulating the balance of cortisol and cortisone in the body, which is important for maintaining normal physiological function. In the medical field, cortisone reductase is of interest because it is involved in the development of certain diseases, such as obesity, diabetes, and cardiovascular disease. In addition, cortisone reductase inhibitors are being studied as potential treatments for these conditions.
Cortisone is a synthetic form of the hormone cortisol, which is produced by the adrenal glands. It is a corticosteroid medication that is used to treat a variety of inflammatory and autoimmune conditions, such as rheumatoid arthritis, lupus, and psoriasis. Cortisone can also be used to treat allergies, asthma, and other respiratory conditions, as well as to reduce swelling and inflammation in the body. It is available in various forms, including tablets, injections, and creams. Cortisone is a potent medication and should only be used under the guidance of a healthcare professional.
Inborn errors of steroid metabolism refer to a group of genetic disorders that affect the body's ability to produce or break down steroids, which are a type of hormone. These disorders can lead to a variety of health problems, including hormonal imbalances, reproductive issues, and susceptibility to infections. There are several different types of inborn errors of steroid metabolism, each caused by a different genetic mutation. Some of the most common include: * Congenital Adrenal Hyperplasia (CAH): This is a group of genetic disorders that affect the adrenal glands, which produce hormones such as cortisol and aldosterone. CAH can cause a range of symptoms, including ambiguous genitalia in newborns, salt-wasting crises, and adrenal insufficiency. * 21-Hydroxylase Deficiency: This is the most common form of CAH, and is caused by a deficiency in the enzyme that converts progesterone to 17-hydroxyprogesterone. It can cause symptoms such as ambiguous genitalia, adrenal insufficiency, and salt-wasting crises. * 11β-Hydroxylase Deficiency: This is another form of CAH, and is caused by a deficiency in the enzyme that converts 17-hydroxyprogesterone to 11-deoxycortisol. It can cause symptoms such as ambiguous genitalia, adrenal insufficiency, and salt-wasting crises. * 3β-Hydroxysteroid Dehydrogenase Deficiency: This is a rare form of CAH, and is caused by a deficiency in the enzyme that converts 17-hydroxyprogesterone to 17-ketosteroids. It can cause symptoms such as ambiguous genitalia, adrenal insufficiency, and salt-wasting crises. Inborn errors of steroid metabolism can be diagnosed through genetic testing and blood tests to measure hormone levels. Treatment typically involves hormone replacement therapy to replace the hormones that are not being produced properly, as well as management of symptoms and complications.
Estranes are a group of synthetic estrogen hormones that are used in various medical applications. They are similar in structure to the naturally occurring estrogen hormone estradiol and are often used as a replacement for estradiol in hormone therapy for conditions such as menopause, osteoporosis, and breast cancer. Estranes are also used in some birth control pills and in veterinary medicine to promote growth and development in animals.
Androstanes are a class of organic compounds that are derived from the androstane ring system, which consists of four fused carbon rings. They are a subclass of the larger group of steroids, which are compounds that are derived from cholesterol and are involved in a wide range of physiological processes in the body. In the medical field, androstanes are often used as a reference for the structure and properties of other steroids. They are also used as a starting point for the synthesis of other steroids, such as testosterone and estradiol, which are important hormones in the body. Some androstanes have been found to have pharmacological activity and are used in the treatment of various conditions, such as prostate cancer, breast cancer, and osteoporosis. For example, the androstane derivative enzalutamide (Xtandi) is a medication that is used to treat advanced prostate cancer.
46, XX Disorders of Sex Development (DSD) are a group of conditions that affect individuals with a typical female chromosomal makeup (46, XX) but have variations in their sex characteristics. These variations can range from mild to severe and can affect the development of the reproductive system, genitalia, and secondary sexual characteristics. The term "disorder of sex development" is preferred over "intersex" because it acknowledges that these conditions are not a result of a person's choices or actions, but rather a result of genetic or hormonal differences. Some common examples of 46, XX DSD include Androgen Insensitivity Syndrome (AIS), which affects the development of the external genitalia and can result in a female with male-typical genitalia, and Congenital Adrenal Hyperplasia (CAH), which can cause ambiguous genitalia or other variations in sex characteristics. Treatment for 46, XX DSD may include hormone therapy, surgery, or other interventions to help individuals develop their sex characteristics in a way that is consistent with their gender identity and preferences. It is important for individuals with 46, XX DSD to receive appropriate medical care and support throughout their lives to help them live healthy and fulfilling lives.
Carbohydrate dehydrogenases are a group of enzymes that catalyze the oxidation of carbohydrates, such as glucose, fructose, and galactose, to produce aldehydes or ketones. These enzymes play important roles in various metabolic pathways, including glycolysis, the citric acid cycle, and the pentose phosphate pathway. There are several types of carbohydrate dehydrogenases, including glucose dehydrogenase, lactate dehydrogenase, and alcohol dehydrogenase. These enzymes are found in a variety of tissues, including the liver, muscle, and brain, and are involved in a range of physiological processes, such as energy metabolism, detoxification, and the synthesis of important molecules like nucleotides and amino acids. In the medical field, carbohydrate dehydrogenases are often used as diagnostic markers for various diseases and conditions. For example, elevated levels of lactate dehydrogenase in the blood can be an indicator of liver or muscle damage, while elevated levels of glucose dehydrogenase can be a sign of certain types of cancer or genetic disorders. Additionally, some carbohydrate dehydrogenases are used as targets for the development of new drugs and therapies.
11-beta-Hydroxysteroid dehydrogenases (11β-HSDs) are a group of enzymes that play a crucial role in regulating the levels of active glucocorticoids in the body. These enzymes are found in various tissues, including the liver, adipose tissue, and the brain. There are two main isoforms of 11β-HSD: 11β-HSD1 and 11β-HSD2. 11β-HSD1 converts inactive cortisone to its active form, cortisol, in the liver and adipose tissue. This enzyme is involved in the regulation of glucose metabolism, insulin sensitivity, and inflammation. On the other hand, 11β-HSD2 converts active cortisol to its inactive form, cortisone, in the kidneys and other tissues. This enzyme helps to protect the body from the harmful effects of excess cortisol, such as weight gain, insulin resistance, and high blood pressure. Dysregulation of 11β-HSD activity has been implicated in various diseases, including obesity, diabetes, cardiovascular disease, and depression. Therefore, understanding the role of 11β-HSDs in the body and developing drugs that target these enzymes may have therapeutic potential for the treatment of these diseases.
11-beta-Hydroxysteroid Dehydrogenase Type 1 (11β-HSD1) is an enzyme that plays a crucial role in regulating the levels of cortisol, a hormone produced by the adrenal gland. It is expressed in various tissues throughout the body, including the liver, muscle, adipose tissue, and brain. The primary function of 11β-HSD1 is to convert inactive cortisone to its active form, cortisol. This conversion occurs in the liver and adipose tissue, where 11β-HSD1 is highly expressed. Cortisol is a key hormone involved in the body's stress response and plays a role in regulating metabolism, immune function, and blood pressure. In addition to its role in cortisol metabolism, 11β-HSD1 has also been implicated in the development of various diseases, including obesity, diabetes, cardiovascular disease, and depression. For example, increased activity of 11β-HSD1 in adipose tissue has been linked to insulin resistance and the development of type 2 diabetes. Similarly, increased activity of 11β-HSD1 in the brain has been linked to depression and anxiety. Overall, 11β-HSD1 is a critical enzyme involved in regulating cortisol metabolism and has important implications for the development of various diseases.
In the medical field, Nitrate Reductases are enzymes that catalyze the reduction of nitrate ions (NO3-) to nitrite ions (NO2-). These enzymes are found in a variety of organisms, including bacteria, plants, and animals. In the context of human health, Nitrate Reductases are of particular interest because they play a role in the production of nitric oxide (NO), a molecule that has a number of important physiological functions. Nitric oxide is a potent vasodilator, meaning that it helps to relax and widen blood vessels, which can improve blood flow and lower blood pressure. In addition to their role in nitric oxide production, Nitrate Reductases have also been implicated in a number of other physiological processes, including the regulation of gene expression, the detoxification of harmful substances, and the maintenance of the balance of oxygen and nitrogen in the body. Overall, Nitrate Reductases are an important class of enzymes that play a variety of roles in human health and physiology.
Hydroxysteroid dehydrogenases (HSDs) are a group of enzymes that play a crucial role in the metabolism of steroid hormones in the body. These enzymes catalyze the conversion of one form of a steroid hormone to another by removing or adding a hydroxyl group. There are several types of HSDs, each with a specific function and localization in the body. For example, some HSDs are found in the liver, where they help regulate the levels of sex hormones such as estrogen and testosterone. Other HSDs are found in the brain, where they play a role in the regulation of mood and behavior. HSDs are also involved in the metabolism of other types of hormones, such as cortisol and aldosterone. Dysfunction of HSDs can lead to a variety of medical conditions, including hormonal imbalances, mood disorders, and metabolic disorders.
Hydroxymethylglutaryl CoA reductases (HMG-CoA reductases) are a class of enzymes that play a critical role in the metabolism of lipids in the body. Specifically, they catalyze the conversion of hydroxymethylglutaryl-CoA (HMG-CoA) to mevalonate, which is a precursor for the synthesis of cholesterol and other isoprenoid compounds. There are two main types of HMG-CoA reductases: HMG-CoA reductase 1 and HMG-CoA reductase 2. HMG-CoA reductase 1 is primarily found in the liver and is responsible for most of the cholesterol synthesis in the body. HMG-CoA reductase 2 is found in other tissues, including the kidneys, adrenal glands, and the small intestine, and is responsible for a smaller amount of cholesterol synthesis. In the medical field, HMG-CoA reductases are important targets for the treatment of hyperlipidemia, a condition characterized by high levels of cholesterol and triglycerides in the blood. Statins, a class of drugs that inhibit HMG-CoA reductase activity, are commonly used to lower cholesterol levels and reduce the risk of cardiovascular disease.
Hydrocortisone is a synthetic glucocorticoid hormone that is used in the medical field to treat a variety of conditions. It is a potent anti-inflammatory and immunosuppressive agent that can help reduce inflammation, swelling, and redness in the body. Hydrocortisone is also used to treat conditions such as allergies, asthma, eczema, and psoriasis, as well as to reduce the symptoms of adrenal insufficiency, a condition in which the body does not produce enough of the hormone cortisol. It is available in a variety of forms, including oral tablets, topical creams, and injections.
Ribonucleotide reductases (RNRs) are a family of enzymes that play a critical role in the biosynthesis of deoxyribonucleotides (dNTPs), which are the building blocks of DNA. RNRs catalyze the conversion of ribonucleotides (rNTPs) to their deoxyribonucleotide counterparts (dNTPs) by removing a phosphate group and reducing the ribose sugar to the deoxyribose form. There are two classes of RNRs: class I and class II. Class I RNRs are found in all organisms and are composed of two subunits: a large subunit (R1) and a small subunit (R2). Class II RNRs are found only in eukaryotes and are composed of four subunits: a large subunit (R1), a small subunit (R2), a third subunit (R3), and a fourth subunit (R4). RNRs are essential for DNA replication and repair, and mutations in the genes encoding RNRs can lead to various diseases, including cancer. In addition, RNRs are also important targets for the development of antiviral and antitumor drugs.
11-beta-Hydroxysteroid Dehydrogenase Type 2 (11β-HSD2) is an enzyme that plays a crucial role in regulating the levels of cortisol, a hormone produced by the adrenal gland. It is primarily found in the liver, kidney, and adipose tissue. The primary function of 11β-HSD2 is to convert cortisol to its inactive form, cortisone. This process helps to prevent cortisol from exerting its effects on various tissues throughout the body, including the brain, muscles, and immune system. In the medical field, 11β-HSD2 is of particular interest because of its role in the development of metabolic disorders such as obesity, insulin resistance, and type 2 diabetes. Studies have shown that individuals with reduced activity of 11β-HSD2 are less likely to develop these conditions, suggesting that the enzyme may play a protective role against metabolic disease. In addition, 11β-HSD2 has been implicated in the development of certain psychiatric disorders, such as depression and anxiety. Research has shown that individuals with reduced activity of 11β-HSD2 may be more susceptible to the effects of stress and may be at increased risk for developing these conditions. Overall, 11β-HSD2 is a critical enzyme that plays a key role in regulating cortisol levels and maintaining metabolic and psychiatric health.
In the medical field, Nitrite Reductases are enzymes that catalyze the reduction of nitrite ions (NO2-) to nitric oxide (NO). Nitric oxide is a signaling molecule that plays a crucial role in various physiological processes, including vasodilation, neurotransmission, and immune function. Nitrite Reductases are found in a variety of organisms, including bacteria, fungi, and plants, and are often used as biomarkers for certain diseases or as therapeutic agents for treating conditions such as erectile dysfunction and cardiovascular disease.
Glutathione Reductase is an enzyme that plays a crucial role in the antioxidant defense system of cells. It catalyzes the reduction of glutathione (GSH) to glutathione disulfide (GSSG) using nicotinamide adenine dinucleotide phosphate (NADPH) as a reducing agent. This reaction is important because GSH is a powerful antioxidant that helps to neutralize reactive oxygen species (ROS) and protect cells from oxidative damage. Glutathione Reductase is found in many tissues throughout the body, including the liver, kidneys, and lungs, and is essential for maintaining cellular health and preventing disease.
FMN Reductase is an enzyme that plays a crucial role in the metabolism of flavin mononucleotide (FMN), a cofactor involved in various cellular processes. FMN Reductase catalyzes the reduction of FMN to flavin adenine dinucleotide (FAD), which is another important cofactor used in many metabolic reactions. In the medical field, FMN Reductase is of interest because it is involved in the metabolism of several drugs and toxins, including the antibiotic rifampicin and the carcinogen benzo[a]pyrene. Mutations in the gene encoding FMN Reductase have been associated with certain genetic disorders, such as Friedreich's ataxia, a neurodegenerative disease characterized by progressive loss of coordination and balance. In addition, FMN Reductase has been studied as a potential target for the development of new drugs for the treatment of various diseases, including cancer, infectious diseases, and neurological disorders.
Thioredoxin-disulfide reductase (TDR) is an enzyme that plays a crucial role in the regulation of cellular redox homeostasis. It catalyzes the reduction of disulfide bonds in proteins, which are important for maintaining the proper structure and function of many proteins in the cell. TDR is involved in a variety of cellular processes, including protein folding, signal transduction, and antioxidant defense. In the medical field, TDR is of interest because it has been implicated in a number of diseases, including cancer, neurodegenerative disorders, and cardiovascular disease. Understanding the role of TDR in these diseases may lead to the development of new therapeutic strategies.
NADPH-Ferrihemoprotein Reductase, also known as NR5A1, is an enzyme that plays a crucial role in the metabolism of iron in the body. It is responsible for reducing ferrihemoprotein (Fe3+) to ferrous hemoprotein (Fe2+), which is an essential step in the absorption and transport of iron in the body. NR5A1 is primarily expressed in the liver, small intestine, and bone marrow, where it is involved in the regulation of iron homeostasis. It is also involved in the metabolism of other metals, such as copper and zinc. Deficiency or dysfunction of NR5A1 can lead to iron deficiency anemia, a condition characterized by low levels of iron in the body, which can cause fatigue, weakness, and other symptoms. It can also lead to other metabolic disorders, such as copper deficiency and zinc deficiency. In the medical field, NADPH-Ferrihemoprotein Reductase is an important target for the development of new treatments for iron deficiency anemia and other metabolic disorders.
Ferredoxin-NADP reductase (FNR) is an enzyme that plays a crucial role in the electron transport chain of photosynthesis and respiration in plants, algae, and some bacteria. It catalyzes the transfer of electrons from ferredoxin, a small iron-sulfur protein, to NADP+ (nicotinamide adenine dinucleotide phosphate), reducing it to NADPH (nicotinamide adenine dinucleotide phosphate hydrogen). In photosynthesis, FNR is involved in the light-dependent reactions, where it receives electrons from the photosystem I complex and passes them on to the photosystem II complex, which uses them to split water molecules and produce oxygen. In respiration, FNR is involved in the light-independent reactions, where it receives electrons from the cytochrome b6f complex and passes them on to the NADP+ pool, which is used in the Calvin cycle to fix carbon dioxide into organic compounds. FNR is a key enzyme in the regulation of photosynthesis and respiration, and its activity is influenced by various factors such as light intensity, temperature, and nutrient availability. Mutations in the FNR gene can lead to defects in photosynthesis and respiration, which can affect plant growth and development.
Oxidoreductases are a class of enzymes that catalyze redox reactions, which involve the transfer of electrons from one molecule to another. These enzymes play a crucial role in many biological processes, including metabolism, energy production, and detoxification. In the medical field, oxidoreductases are often studied in relation to various diseases and conditions. For example, some oxidoreductases are involved in the metabolism of drugs and toxins, and changes in their activity can affect the efficacy and toxicity of these substances. Other oxidoreductases are involved in the production of reactive oxygen species (ROS), which can cause cellular damage and contribute to the development of diseases such as cancer and aging. Oxidoreductases are also important in the diagnosis and treatment of certain diseases. For example, some oxidoreductases are used as markers of liver disease, and changes in their activity can indicate the severity of the disease. In addition, some oxidoreductases are targets for drugs used to treat diseases such as cancer and diabetes. Overall, oxidoreductases are a diverse and important class of enzymes that play a central role in many biological processes and are the subject of ongoing research in the medical field.
Cytochrome reductases are a group of enzymes that play a crucial role in the electron transport chain, which is a series of chemical reactions that generate energy in the form of ATP (adenosine triphosphate) in cells. These enzymes are responsible for transferring electrons from electron donors to electron acceptors, such as cytochromes, and are found in the inner mitochondrial membrane in eukaryotic cells and in the plasma membrane in prokaryotic cells. Cytochrome reductases are involved in a variety of metabolic processes, including the breakdown of fatty acids, the synthesis of cholesterol, and the detoxification of harmful substances. They are also important in the production of reactive oxygen species (ROS), which can damage cells and contribute to the development of various diseases, including cancer and neurodegenerative disorders. In the medical field, cytochrome reductases are the target of several drugs, including statins, which are used to lower cholesterol levels, and anticancer drugs, which target the enzymes to disrupt the electron transport chain and kill cancer cells.
Cortisone reductase deficiency
List of OMIM disorder codes
3alpha(or 20beta)-hydroxysteroid dehydrogenase
Polycystic ovary syndrome
11β-Hydroxysteroid dehydrogenase type 1
Index of molecular biology articles
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List of steroid abbreviations
History of intersex surgery
Cortisone reductase deficiency - Wikipedia
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- We and others have demonstrated decreased hepatic cortisol regeneration through reduced 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity that converts inactive cortisone to cortisol. (endocrine-abstracts.org)
- In addition, there is enhanced cortisol clearance by A-ring reductases, (notably 5α-reductase). (endocrine-abstracts.org)
- [ 22 , 23 ] In obesity, postulated mechanisms of hyperactivation of HPA axis include hyper-responsiveness to different neuropeptides, stress events, dietary factors, as well as a stimulation caused by augmented peripheral metabolism and clearance of cortisol by reduced conversion of cortisone to cortisol by 11β-HSD1 and increased conversion of cortisol to 5α-reduced derivatives. (medscape.com)
- 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a key enzyme that transform cortisone to cortisol, which activates the endogenous glucocorticoid function. (ijbs.com)
- Cortisol / cortisone ratio indicates activity of HSD11B2 activity and assessment of tissue specific concentrations of cortisol, which normally cannot be measured without a biopsy. (healthmatters.io)
- However, it's most unique trait and indeed what makes it extremely desirable, lies in the fact that it is capable of selectively inhibiting the function of the 11beta-HSD isoform known as '11b-hydroxysteroid dehydrogenase type 1′ (11beta-HSD1) or 'cortisone reductase', an enzyme responsible for converting cortisone to the catabolic hormone c ortisol in target tissues such as adipose, liver and skeletal muscle. (blackdiamondsupplements.com)
- It's what you get when testosterone is exposed to the enzyme Type II 5-alpha reductase. (scalpmicrousa.com)
- Any extra glucose that is absorbed into the lens is converted to sorbitol by an enzyme called aldose reductase. (vin.com)
- It is metabolized via the 5-alpha metabolic pathway (= increased 5α-reductase activity). (healthmatters.io)
- Kinostat is an aldose reductase inhibitor that curtails sorbitol production. (vin.com)
- 15. Mutations in the genes encoding 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase interact to cause cortisone reductase deficiency. (nih.gov)
- In-Depth Dissection of the P133R Mutation in Steroid 5β-Reductase (AKR1D1): A Molecular Basis of Bile Acid Deficiency. (nih.gov)
- 2. Expression and NNK reducing activities of carbonyl reductase and 11beta-hydroxysteroid dehydrogenase type 1 in human lung. (nih.gov)
- 4. Interindividual variability in the expression and NNK carbonyl reductase activity of 11beta-hydroxysteroid dehydrogenase 1 in human lung. (nih.gov)
- 16. Purification, characterization and NNK carbonyl reductase activities of 11beta-hydroxysteroid dehydrogenase type 1 from human liver: enzyme cooperativity and significance in the detoxification of a tobacco-derived carcinogen. (nih.gov)
- Testosterone supplementation while undergoing exercise training typically has the dehydrogenase Type 1, which, although bidirectional, acts predominantly in most tissues as a reductase converting cortisone to cortisol. (lunokhod.org)
- AKR1D1 (steroid 5beta-reductase) reduces all Delta(4)-3-ketosteroids to form 5beta-dihydrosteroids, a first step in the clearance of steroid hormones and an essential step in the synthesis of all bile acids. (nih.gov)
- Here, we report the first x-ray crystal structure of a mammalian steroid hormone carbon-carbon double bond reductase, human Delta(4)-3-ketosteroid 5beta-reductase (AKR1D1), and its complexes with intact substrates. (nih.gov)
- We have determined the structures of AKR1D1 complexes with NADP(+) at 1.79- and 1.35-A resolution (HEPES bound in the active site), NADP(+) and cortisone at 1.90-A resolution, NADP(+) and progesterone at 2.03-A resolution, and NADP(+) and testosterone at 1.62-A resolution. (nih.gov)
- Human steroid-5β-reductase (aldo-keto reductase 1D1, AKR1D1) stereospecifically reduces Δ(4)-3-ketosteroids to 5β-dihydrosteroids and is essential for steroid hormone metabolism and bile acid biosynthesis. (nih.gov)
- Not only is glial cell cholesterol synthesis in our brains vital for memory function and cognition, cholesterol also is the substrate for our most important homones: aldosterone, cortisone, estrogen, progesterone and testosterone as well as the quasi-hormone, vitamin D (calcitrol). (rawhorizons.com)
- The reduction of the carbon-carbon double bond in an alpha,beta-unsaturated ketone by 5beta-reductase is a unique reaction in steroid enzymology because hydride transfer from NADPH to the beta-face of a Delta(4)-3-ketosteroid yields a cis-A/B-ring configuration with an approximately 90 degrees bend in steroid structure. (nih.gov)
- An enzyme that catalyzes the interconversion of a ketone and hydroxy group at C-20 of cortisone and other 17,20,21-trihydroxy steroids. (nih.gov)
- Statins act by inhibiting HMG-CoA reductase as indicated in this figure. (rawhorizons.com)
- The disease-associated P133R mutation caused significant decreases in catalytic efficiency with both the representative steroid (cortisone) and the bile acid precursor (7α-hydroxycholest-4-en-3-one) substrates. (nih.gov)
- The reasons for statin drug side effects are better appreciated by using this figure of the Mevalonate Pathway ( also known as the HMG-CoA reductase pathway ) adapted from any medical school biochemistry book. (rawhorizons.com)
- Activity of 17α-hydroxylase/17,20-lyase (CYP17A1), essential for androgen biosynthesis, was decreased after fasting in healthy women as were 21-hydroxylase (CYP21A2) and 5α-reductase activities. (medscape.com)
- On the other hand, dealing with hair loss related to skin problems is the hardest to treat, he says, but these too may respond to creams or anti-inflammatories injections with cortisone or immune-suppressing drugs. (hairlossprotalk.com)