Steroids that contain a ketone group at position 17.
Steroid derivatives formed by oxidation of a methyl group on the side chain or a methylene group in the ring skeleton to form a ketone.
A group of hydroxycorticosteroids bearing a hydroxy group at the 17-position. Urinary excretion of these compounds is used as an index of adrenal function. They are used systemically in the free alcohol form, but with esterification of the hydroxy groups, topical effectiveness is increased.
Catalyze the oxidation of 3-hydroxysteroids to 3-ketosteroids.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

Accumulation of 3-ketosteroids induced by itraconazole in azole-resistant clinical Candida albicans isolates. (1/70)

The effects of itraconazole on ergosterol biosynthesis were investigated in a series of 16 matched clinical Candida albicans isolates which had been previously analyzed for mechanisms of resistance to azoles (D. Sanglard, K. Kuchler, F. Ischer, J. L. Pagani, M. Monod, and J. Bille, Antimicrob. Agents Chemother., 39:2378-2386, 1995). Under control conditions, all isolates contained ergosterol as the predominant sterol, except two strains (C48 and C56). In isolates C48 and C56, both less susceptible to azoles than their parent, C43, substantial concentrations (20 to 30%) of 14alpha-methyl-ergosta-8,24(28)-diene-3beta,6alpha-dio l (3, 6-diol) were found. Itraconazole treatment of C43 resulted in a dose-dependent inhibition of ergosterol biosynthesis (50% inhibitory concentration, 2 nM) and accumulation of 3,6-diol (up to 60% of the total sterols) together with eburicol, lanosterol, obtusifoliol, 14alpha-methyl-ergosta-5,7,22,24(28)-tetraene-3betaol, and 14alpha-methyl-fecosterol. In strains C48 and C56, no further increase of 3,6-diol was observed after exposure to itraconazole. Ergosterol synthesis was less sensitive to itraconazole inhibition, as was expected for these azole-resistant isolates which overexpress ATP-binding cassette transporter genes CDR1 and CDR2. In addition to 3,6-diol, substantial amounts of obtusifolione were found after exposure to itraconazole. This toxic 3-ketosteroid was demonstrated previously to accumulate after itraconazole treatment in Cryptococcus neoformans and Histoplasma capsulatum but has not been reported in Candida isolates. Accumulation of obtusifolione correlated with nearly complete growth inhibition in these azole-resistant strains compared to that found in the susceptible parent strain, although the onset of growth inhibition only occurred at higher concentrations of itraconazole. ERG25 and ERG26 are the only genes assigned to the 4-demethylation process, of which the 3-ketoreductase is part. To verify whether mutations in these ERG25 genes contributed to obtusifolione accumulation, their nucleotide sequences were determined in all three related isolates. No mutations in ERG25 alleles of isolates C48 and C56 were found, suggesting that this gene is not involved in obtusifolione accumulation. The molecular basis for the accumulation of this sterol in these two strains remains to be established.  (+info)

Inhibition of the steroidogenic effects of cholera and heat-labile Escherichia coli enterotoxins by GM1 ganglioside: evidence for a similar receptor site for the two toxins. (2/70)

The effects of three different ganglioside preparations on cholera enterotoxin (CT) and heat-labile Escherichia coli enterotoxin (ECT)-induced steroidogenesis in Y1 and OS3 adrenal tumor cells in tissue culture were examined. Only with GM1 ganglioside was any inhibition of the toxins' effects noted. Concentrations of the crude ECT preparation that gave similar morphogenic and steroidogenic effects as CT were inhibited by the same amount or less of GM1 as that required to inhibit the effects of CT. The results of competition experiments also demonstrated that previous incubation of GM1 with one toxin could inhibit the ganglioside's ability to inactivate the other toxin. These findings indicate that at least for Y1 and OS3 adrenal tumor cells, GM1 may resemble or be the receptor for both CT and ECT.  (+info)

Biosynthesis of bile acids in man. Hydroxylation of the C27-steroid side chain. (3/70)

The first step in the degradation of the steroid side chain during biosynthesis of bile acids from cholesterol in man was studied in microsomal and mitochondrial fraction of homogenate of livers from 14 patients. The microsomal fraction was found to catalyze an efficient 25-hydroxylation of 5,8-cholestane-3a,7a,12atriol. A small extent of 23-, 24-, and 26-hydroxylation of the same substrate was observed. 53-Cholestane-3a,7adiol was hydroxylated in the 25-position only to a very small extent. The mitochondrial fraction was found to catalyze 26-hydroxylation of cholesterol, 5-cholestene-3P,7a-diol, 5P-cholestane-3a,7a-diol, 7a-hydroxy-4-cholesten-3-one, and 5,0-cholestane-3a,7a,12a-triol. Addition of Mg++ stimulated the 26-hydroxylation of cholesterol but had no effect or an inhibitory effect on 26-hydroxylation of the other substrates, indicating a heterogeneity of the mitochondrial 26-hydroxylating system. The level of 26-hydroxylase activity towards different substrates varied considerably with different mitochondrial preparations. The roles of the microsomal and mitochondrial 26- hydroxylations as well as the microsomal 25-hydroxylation in biosynthesis of bile acids in man are discussed. The results indicate that microsomal 26-hydroxylation is less important than mitochondrial 26-hydroxylation under normal conditions. The possibility that microsomal 25-hydroxylation is important cannot be ruled out.  (+info)

Cholesterol ester formation in cultured human fibroblasts. Stimulation by oxygenated sterols. (4/70)

Incubation of monolayers of cultured human fibroblasts with oxygenated sterols (25-hydroxycholesterol, 7-ketocholesterol, or 6-ketocholestanol) markedly enhanced the rate at which the cells esterified their endogenous cholesterol and produced an increase in the cellular content of cholesterol esters. The enhanced esterification capacity was associated with an increase in the activity of a membrane-bound fatty acyl-CoA:cholesteryl acyltransferase. Incubation of cells for 5 hours with 5 mug/ml of 25-hydroxycholesterol produced an 8-fold increase in the specific activity of this enzyme when assayed in cell-free extracts. Since the oxygenated sterols that elevated the activity of fatty acyl-CoA:cholesteryl acyl-transferase also suppressed the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase, the data suggest that the processes of cholesterol ester formation and cholesterol synthesis in human fibroblasts are regulated in a reciprocal manner by coordinate changes in the activities of these two membrane-bound enzymes.  (+info)

Roles of dimerization in folding and stability of ketosteroid isomerase from Pseudomonas putida biotype B. (5/70)

Equilibrium and kinetic analyses have been performed to elucidate the roles of dimerization in folding and stability of KSI from Pseudomonas putida biotype B. Folding was reversible in secondary and tertiary structures as well as in activity. Equilibrium unfolding transition, as monitored by fluorescence and ellipticity measurements, could be modeled by a two-state mechanism without thermodynamically stable intermediates. Consistent with the two-state model, one dimensional (1D) NMR spectra and gel-filtration chromatography analysis did not show any evidence for a folded monomeric intermediate. Interestingly enough, Cys 81 located at the dimeric interface was modified by DTNB before unfolding. This inconsistent result might be explained by increased dynamic motion of the interface residues in the presence of urea to expose Cys 81 more frequently without the dimer dissociation. The refolding process, as monitored by fluorescence change, could best be described by five kinetic phases, in which the second phase was a bimolecular step. Because <30% of the total fluorescence change occurred during the first step, most of the native tertiary structure may be driven to form by the bimolecular step. During the refolding process, negative ellipticity at 225 nm increased very fast within 80 msec to account for >80% of the total amplitude. This result suggests that the protein folds into a monomer containing most of the alpha-helical structures before dimerization. Monitoring the enzyme activity during the refolding process could estimate the activity of the monomer that is not fully active. Together, these results stress the importance of dimerization in the formation and maintenance of the functional native tertiary structure.  (+info)

Concentration-dependent association of delta5-3-ketosteroid isomerase of Pseudomonas testosteroni. (6/70)

Gel chromatography and ultracentrifugation studies show that delta5-3-ketosteroid isomerase of Pseudomonas testosteroni a dimer with a molecular weight of 26,800 at concentrations below 1 mg per ml, undergoes reversible, concentration-dependent association at higher enzyme concentrations. In the concentration range between 0.04 and 15.6 mg per ml, apparent molecular radii of 23 A to 36 A and molecular weights of 26,000 to 69,000 were observed. The latter value represents the weight average molecular weight of two or more ploymerization species in rapid equilibrium, rather than a discrete polymeric form of the enzyme. The isomerase dimer has been found to be unusually stable to dissociation upon dilution, even at concentrations in the nanogram per ml range. Evidence is presented which suggests that the enzyme is present as a dimer in P. testosteroni cells and that this is a catalytically active species. The isomerase monomer has been obtained and its molecular weight studied by gel electrophoresis in the presence of sodium dodecyl sulfate. A new determination of the extinction coefficient of the isomerase gives the value of 0.336 for the absorbance at 280 nm in a 1-cm light path of a solution containing 1 mg of the isomerase per ml.  (+info)

0-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride as a sensitive derivatizing agent for the electron capture gas liquid chromatographic analysis of keto steroids. (7/70)

0-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride was used to prepare oximes of steroids with keto groups in selected positions; 3,17 and 20-monoketo; 3,17 and 3,20-diketo. Some of the 3-keto steroids had hindered 17-hydroxyl groups which were not readily amenable to esterification with perfluoroanhydrides, the most commonly used derivatizing agents for electron capture gas chromatographic analysis of hydroxy steroids. The oximes were readily prepared from 5 ng of each of the compounds tested, and with testosterone it was demonstrated that the derivative could be prepared from as little as 0.1 ng. The derivatives were stable to gas chromatography and extremely sensitive to electron capture detection. The sensitivity ranged from 1.5 X 10(4) coulombs per mole of progesterone. Because of the ease of preparation of the derivatives, their stability in common solvents and analytical manipulative techniques, the reagent would be suitable for the micro analysis of biologically significant keto steroids by electron capture gas chromatography.  (+info)

Chemical modification of amino acid residues associated with the delta-4-3-ketosteroid-dependent photoinactivation of delta-5-3-ketosteroid isomerase. (8/70)

The photoinactivation of the Delta (5)-3-ketosteroid isomerase of Pseudomonas testosteroni in the presence of 3-oxo-4-estren-17beta-yl acetate and air is accompanied by destruction of histidine and aspartate (or asparagine). The first order rate constant of photoinactivation of the enzyme is equal, within experimental error, to the first order rate constant for the destruction of a single aspartate (or asparagine) residue and is considerably greater than the first order rate constant for the destruction of a single residue of histidine. When the photolysis is carried out under anaerobic conditions, only aspartic acid (or asparagine) is destroyed as enzyme is inactivated. Both inactivation and aspartate (or asparagine) destruction occur to a greater extent in the absence of oxygen than in its presence. The destruction of histidine, on the other hand, is found to be strictly oxygen-dependent. These results suggest that photochemical modification of a single residue of aspartate (or asparagine) is largely, if not entirely, responsible for photoinactivation of the enzyme under these conditions. When irradiated in the presence of 3-oxo-4-entren-17beta-yl acetate, performic acid-oxidized bovine pancreatic ribonuclease does not suffer any detectable destruction of its aspartic or asparaginyl residues but does undergo significant destruction of its histidine residues. These observations suggest that the aspartate (or asparagine) residue modification found with isomerase is an active site-directed photochemical reaction, whereas the modification of histidine may not be.  (+info)

17-Ketosteroids are a group of steroid compounds that contain a ketone group at the 17th carbon position in their molecular structure. They are produced as metabolic byproducts of certain hormones, such as androgens and estrogens, in the human body.

The term "17-KS" or "17-ketosteroids" is often used to refer to a class of urinary steroid metabolites that can be measured in the urine to assess adrenal and gonadal function. The measurement of 17-KS is particularly useful in monitoring patients with certain endocrine disorders, such as congenital adrenal hyperplasia or adrenal tumors.

The two major 17-KS that are routinely measured in urine are androsterone and etiocholanolone, which are derived from the metabolism of testosterone and dehydroepiandrosterone (DHEA), respectively. Other 17-KS include tetrahydrocortisone, tetrahydrocortisol, and 5-androstene-3β,17β-diol.

It's worth noting that the measurement of 17-KS has largely been replaced by more specific tests, such as the measurement of individual steroid hormones or their metabolites using mass spectrometry-based methods.

Ketosteroids are a type of steroid compound that contain a ketone functional group in their chemical structure. They are derived from cholesterol and are present in both animal and plant tissues. Some ketosteroids are produced endogenously, while others can be introduced exogenously through the diet or medication.

Endogenous ketosteroids include steroid hormones such as testosterone, estradiol, and cortisol, which contain a ketone group in their structure. Exogenous ketosteroids can be found in certain medications, such as those used to treat hormonal imbalances or inflammation.

Ketosteroids have been studied for their potential therapeutic uses, including as anti-inflammatory agents and for the treatment of hormone-related disorders. However, more research is needed to fully understand their mechanisms of action and potential benefits.

17-Hydroxycorticosteroids are a class of steroid hormones that are produced in the adrenal gland. They are formed from the metabolism of cortisol, which is a hormone that helps regulate metabolism, immune response, and stress response. 17-Hydroxycorticosteroids include compounds such as cortisone and corticosterone.

These hormones have various functions in the body, including:

* Regulation of carbohydrate, fat, and protein metabolism
* Suppression of the immune system
* Modulation of the stress response
* Influence on blood pressure and electrolyte balance

Abnormal levels of 17-hydroxycorticosteroids can indicate problems with the adrenal gland or pituitary gland, which regulates adrenal function. They are often measured in urine or blood tests to help diagnose conditions such as Cushing's syndrome (overproduction of cortisol) and Addison's disease (underproduction of cortisol).

3-Hydroxysteroid dehydrogenases (3-HSDs) are a group of enzymes that play a crucial role in steroid hormone biosynthesis. These enzymes catalyze the conversion of 3-beta-hydroxy steroids to 3-keto steroids, which is an essential step in the production of various steroid hormones, including progesterone, cortisol, aldosterone, and sex hormones such as testosterone and estradiol.

There are several isoforms of 3-HSDs that are expressed in different tissues and have distinct substrate specificities. For instance, 3-HSD type I is primarily found in the ovary and adrenal gland, where it catalyzes the conversion of pregnenolone to progesterone and 17-hydroxyprogesterone to 17-hydroxycortisol. On the other hand, 3-HSD type II is mainly expressed in the testes, adrenal gland, and placenta, where it catalyzes the conversion of dehydroepiandrosterone (DHEA) to androstenedione and androstenedione to testosterone.

Defects in 3-HSDs can lead to various genetic disorders that affect steroid hormone production and metabolism, resulting in a range of clinical manifestations such as adrenal insufficiency, ambiguous genitalia, and sexual development disorders.

Substrate specificity in the context of medical biochemistry and enzymology refers to the ability of an enzyme to selectively bind and catalyze a chemical reaction with a particular substrate (or a group of similar substrates) while discriminating against other molecules that are not substrates. This specificity arises from the three-dimensional structure of the enzyme, which has evolved to match the shape, charge distribution, and functional groups of its physiological substrate(s).

Substrate specificity is a fundamental property of enzymes that enables them to carry out highly selective chemical transformations in the complex cellular environment. The active site of an enzyme, where the catalysis takes place, has a unique conformation that complements the shape and charge distribution of its substrate(s). This ensures efficient recognition, binding, and conversion of the substrate into the desired product while minimizing unwanted side reactions with other molecules.

Substrate specificity can be categorized as:

1. Absolute specificity: An enzyme that can only act on a single substrate or a very narrow group of structurally related substrates, showing no activity towards any other molecule.
2. Group specificity: An enzyme that prefers to act on a particular functional group or class of compounds but can still accommodate minor structural variations within the substrate.
3. Broad or promiscuous specificity: An enzyme that can act on a wide range of structurally diverse substrates, albeit with varying catalytic efficiencies.

Understanding substrate specificity is crucial for elucidating enzymatic mechanisms, designing drugs that target specific enzymes or pathways, and developing biotechnological applications that rely on the controlled manipulation of enzyme activities.

A 17-ketosteroid is a ketosteroid in which the ketone is located specifically at the C17 position (in the upper right corner of ... A ketosteroid, or an oxosteroid, is a steroid in which a hydrogen atom has been replaced with a ketone (C=O) group. ... Hydroxysteroid Hydroxysteroid dehydrogenase 17-Ketosteroids at the U.S. National Library of Medicine Medical Subject Headings ( ... most structure diagrams). Examples of 17-ketosteroids include: Androstenedione Androstanedione Androsterone ...
Ketosteroid+monooxygenase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology (Articles ... Ketosteroid monooxygenase (EC 1.14.13.54, steroid-ketone monooxygenase, progesterone, NADPH2:oxygen oxidoreductase (20- ... H2O Ketosteroid monooxygenase is a single FAD-containing enzyme that catalyses three types of monooxygenase reaction. Katagiri ... is an enzyme with systematic name ketosteroid,NADPH:oxygen oxidoreductase (20-hydroxylating, ester-producing/20-hydroxylating, ...
In enzymology, a 3-keto-steroid reductase (EC 1.1.1.270) is an enzyme that catalyzes the chemical reaction 4alpha-methyl-5alpha ... Formation and metabolism of 3-ketosteroid intermediates". J. Biol. Chem. 243 (21): 5546-55. PMID 4387005. Portal: Biology v t e ... Billheimer JT, Alcorn M, Gaylor JL (1981). "Solubilization and partial purification of a microsomal 3-ketosteroid reductase of ...
... (EC 1.14.13.142, KshAB, 3-ketosteroid 9alpha-hydroxylase) is an enzyme with systematic name ... 3-ketosteroid+9alpha-monooxygenase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology ( ... Capyk JK, Casabon I, Gruninger R, Strynadka NC, Eltis LD (November 2011). "Activity of 3-ketosteroid 9α-hydroxylase (KshAB) ... Capyk JK, D'Angelo I, Strynadka NC, Eltis LD (April 2009). "Characterization of 3-ketosteroid 9{alpha}-hydroxylase, a Rieske ...
... correlation with the urinary 17-ketosteroids". AMA Arch Derm Syphilol. 65 (5): 601-8. doi:10.1001/archderm.1952.01530240093012 ...
3-ketosteroid isomerase just transfers a double bond at Δ5 of 3-ketosteroid to Δ4. A Δ5-3-ketosteroid isomerase-disrupted ... Δ5-ketosteroid isomerase, Δ5(or Δ4)-3-keto steroid isomerase, Δ5-steroid isomerase, 3-oxosteroid isomerase, Δ5-3-keto steroid ... Cho HS, Choi G, Choi KY, Oh BH (June 1998). "Crystal structure and enzyme mechanism of Delta 5-3-ketosteroid isomerase from ... Talalay P, Benson AM (1972). "Δ5-3-Ketosteroid Isomerase". In Boyer PD (ed.). The Enzymes. Vol. 6 (3rd ed.). Academic Press. pp ...
Furuebisu M, Deguchi S, Okuda K (March 1987). "Identification of cortisone 5 beta-reductase as delta 4-3-ketosteroid 5 beta- ... Okuda A, Okuda K (June 1984). "Purification and characterization of delta 4-3-ketosteroid 5 beta-reductase". The Journal of ... Tomkins GM (March 1957). "The enzymatic reduction of delta 4-3-ketosteroids". The Journal of Biological Chemistry. 225 (1): 13- ... Δ4-3-ketosteroid 5β-reductase, Δ4-5β-reductase, Δ4-hydrogenase, 4,5β-dihydrocortisone:NADP+ Δ4-oxidoreductase, 3-oxo-5β-steroid ...
Bagramian ER, Bogdanova EA, Krymskaia ML, Sokovykh SI (February 1977). "[Diagnostic importance of determining 17-ketosteroids ...
The earliest PubChem patent record for 16-DPA is US2656364A of 1951, describing its conversion into 17-ketosteroids. Mexican ... Hershberg, Emanuel B.; Oliveto, Eugene P. (20 October 1953). "Process for the manufacture of 17-keto steroids". Ramakrishna, ...
Hamburger, Christian (1952). "17-Ketosteroid Excretion and Modes of Administering Testosterone Preparations". Ciba Foundation ... "Testosterone treatment and 17-ketosteroid excretion. V. Administration of testosterone per rectum". Acta Endocrinol. 28 (4): ...
List of androgen esters § Testosterone esters Hamburger C (August 1956). "Testosterone treatment and 17-ketosteroid excretion. ...
Gallagher, T. F.; Kritchevsky, Theodore H. (1950). "Perbenzoic Acid Oxidation of 20-Ketosteroids and the Stereochemistry of C- ...
The term '17-keto steroids', often used in the medical literature, is incorrect because C-17 is specified twice, as the term ... Microbial catabolism of phytosterol side chains yields C-19 steroids, C-22 steroids, and 17-ketosteroids (i.e. precursors to ... "17-ketosteroid" is also important in medicine. The gonane (steroid nucleus) is the parent 17-carbon tetracyclic hydrocarbon ... 11-oxo steroids rather than 11-keto steroids), because "keto" includes the carbon that is part of the steroid nucleus and the ...
247-. ISBN 978-1-60795-008-0. Hamburger C (1952). "17-Ketosteroid Excretion and Modes of Administering Testosterone ...
For example, ethynylation of 17-ketosteroids produces important contraceptive medications known as progestins. Examples include ...
"Male pseudohermaphroditism with gynaecomastia due to testicular 17-ketosteroid reductase deficiency". Clinical Endocrinology. 7 ...
... and 3-ketosteroids (group NR3C). In addition to nuclear receptors, several G protein-coupled receptors and ion channels act as ... 3-Ketosteroid receptors 1: Glucocorticoid receptor (GR; NR3C1) (Cortisol) 2: Mineralocorticoid receptor (MR; NR3C2) ( ...
Similar stereoelectronic effects were observed in studies of the rearrangement of 17-hydroxy-20-ketosteroids. In this case, ...
"Changes in the excretion pattern of neutral 17-ketosteroids during oestrogen administration to male subjects". The Journal of ...
This reaction is the basis of the Zimmermann test used for the detection of ketosteroids. The Jackson-Meisenheimer complex was ...
Beranič N, Gobec S, Rižner TL (May 2011). "Progestins as inhibitors of the human 20-ketosteroid reductases, AKR1C1 and AKR1C3 ...
401-. ISBN 978-0-412-02791-8. Beranič N, Gobec S, Rižner TL (May 2011). "Progestins as inhibitors of the human 20-ketosteroid ...
These enzymes also catalyze the reverse reaction, acting as ketosteroid reductases (KSRs). There are four types, classified by ...
Fried SD, Bagchi S, Boxer SG (December 2014). "Extreme electric fields power catalysis in the active site of ketosteroid ...
"Progestins as inhibitors of the human 20-ketosteroid reductases, AKR1C1 and AKR1C3". Chem. Biol. Interact. 191 (1-3): 227-33. ...
1964;34:1401-3. Polish) EXCRETION OF UROPEPSIN AND 17-KETOSTEROIDS IN PATIENTS WITH RESPIRATORY INSUFFICIENCY (Pol Arch Med ...
His later research covered topics including androgen hormones, 17-ketosteroids, antigonadotropins, and methods for ...
"Regulation of the gene for estrogenic 17-ketosteroid reductase lying on chromosome 17cen----q25". The Journal of Biological ...
Chen M, Penning TM (May 2014). "5β-Reduced steroids and human Δ(4)-3-ketosteroid 5β-reductase (AKR1D1)". Steroids. 83: 17-26. ...
Studies on ketosteroid isomerase have provided experimental evidence that the enzyme actually enhances the coupled motion/ ... "Experimental evidence for enzyme-enhanced coupled motion/quantum mechanical hydrogen tunneling by ketosteroid isomerase". ...
A 17-ketosteroid is a ketosteroid in which the ketone is located specifically at the C17 position (in the upper right corner of ... A ketosteroid, or an oxosteroid, is a steroid in which a hydrogen atom has been replaced with a ketone (C=O) group. ... Hydroxysteroid Hydroxysteroid dehydrogenase 17-Ketosteroids at the U.S. National Library of Medicine Medical Subject Headings ( ... most structure diagrams). Examples of 17-ketosteroids include: Androstenedione Androstanedione Androsterone ...
Learn about 17-Ketosteroids at online-medical-dictionary.org ...
... By Miriam Pollak 04.06.2017 Dehydroepiandrosterone (DHEA); 4-androstene-3, ... 2016) "Validation of highly sensitive simultaneous targeted and untargeted analysis of keto-steroids by Girard P derivatization ...
"17-Ketosteroids" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical Subject ... This graph shows the total number of publications written about "17-Ketosteroids" by people in this website by year, and ... Below are the most recent publications written about "17-Ketosteroids" by people in Profiles. ... Below are MeSH descriptors whose meaning is more general than "17-Ketosteroids". ...
The reference range of urinary 17-ketosteroids is as follows: Males: 10-20 mg (34-69 µmol)/24 h Females: 5-15 mg (17-52 µmol)/ ... The 17-ketosteroids are breakdown products of androgens. Examples of 17-ketosteroids include androstenedione, androsterone, ... encoded search term (17-Ketosteroids) and 17-Ketosteroids What to Read Next on Medscape ... Newer tests have superseded 17-ketosteroid testing, and the assay is seldom used now. ...
The reference range of urinary 17-ketosteroids is as follows: Males: 10-20 mg (34-69 µmol)/24 h Females: 5-15 mg (17-52 µmol)/ ... The 17-ketosteroids are breakdown products of androgens. Examples of 17-ketosteroids include androstenedione, androsterone, ... encoded search term (17-Ketosteroids) and 17-Ketosteroids What to Read Next on Medscape ... Newer tests have superseded 17-ketosteroid testing, and the assay is seldom used now. ...
Home Pathology 17 - HYDROXYCORTICOSTEROIDS & 17 - KETOSTEROIDS, 24-HOUR URINE. 17 - HYDROXYCORTICOSTEROIDS & 17 - KETOSTEROIDS ...
The preprint of the paper Universal Capability of 3-Ketosteroid Δ1-Dehydrogenases to Catalyze Δ1-Dehydrogenation of C17- ... MLBKE scientists managed to show that 3-ketosteroid dehydrogenases (KSTD) exhibit universal capabilities of catalysing ... dehydrogenation of 3-ketosteroids with undegraded C-17 substituent (this long black chain sticking out of the enzyme in the ...
Leydig cell tumors (see the image below) are rare testicular tumors of the male gonadal interstitium that may be hormonally active and lead to feminizing or virilizing syndromes.{file39581}Signs and symptoms Clinical manifestations include the following: A nontender palpable testicular mass or nodule Precocious puberty in prepubertal boys wit...
Levels of 17-hydroxycorticosteroids and 17-ketosteroids in maternal and cord plasma in term anencephaly. The Journal of ... NICHOLS, J. ; LESCURE, O. L. ; MIGEON, C. J. / Levels of 17-hydroxycorticosteroids and 17-ketosteroids in maternal and cord ... NICHOLS, J., LESCURE, O. L., & MIGEON, C. J. (1958). Levels of 17-hydroxycorticosteroids and 17-ketosteroids in maternal and ... Levels of 17-hydroxycorticosteroids and 17-ketosteroids in maternal and cord plasma in term anencephaly. / NICHOLS, J.; LESCURE ...
These enzymes each degrade aromatic heterocycles and/or phenols, whereas 3-ketosteroid-9-α-hydroxylase (KshA15) catabolizes the ... Capyk, J. K., DAngelo, I., Strynadka, N. C. & Eltis, L. D. Characterization of 3-ketosteroid 9α-hydroxylase, a Rieske ... 3-ketosteroid-9-α-hydroxylase; 6ICK, NdmA; 6ICL, NdmB. b Rieske monohydroxylases SxtT and GxtA catalyze highly selective C-H ... cycloalkane rings of ketosteroids. The disparity between the large number of known Rieske oxygenases and the number that have ...
Although ketosteroid isomerase (KSI) is a commonly used affinity tag for expression and purification of short peptides, KSI tag ... expression-and-purification-of-the-p75-neurotrophin-receptor-transmembrane-domain-using-a-ketosteroid-isomerase-tag.pdf 1.11 MB ... Li et al: Expression and purification of the p75 neurotrophin receptor transmembrane domain using a ketosteroid isomerase tag. ... Expression and purification of the p75 neurotrophin receptor transmembrane domain using a ketosteroid isomerase tag ...
Catalytic Domain, Hydrogen Bonding, Ion Transport, Ketosteroids, Models, Molecular, Protons, Pseudomonas putida, ... Quantitative dissection of hydrogen bond-mediated proton transfer in the ketosteroid isomerase active site.. ... Quantitative dissection of hydrogen bond-mediated proton transfer in the ketosteroid isomerase active site.. ... of the proton transfer equilibrium within a hydrogen bond network formed to bound phenols in the active site of ketosteroid ...
Tags: Electronic inductive effects, hydrogen bond coupling, hydrogen bonding, Ketosteroid Isomerase. Share this entry. *Share ... Hydrogen bonding in the active site of ketosteroid isomerase: Electronic inductive effects and hydrogen bond coupling. 134. P. ... Calculation of vibrational shifts of nitrile probes in the active site of ketosteroid isomerase upon ligand binding ... Impact of mutation on proton transfer reactions in ketosteroid isomerase: Insights from molecular dynamics simulations. ...
5beta-Reduced steroids and human Delta(4)-3-ketosteroid 5beta-reductase (AKR1D1). Steroids. 2014 May;83:17-26. doi: 10.1016/j. ...
Testosterone is metabolized to various 17-keto steroids through two different pathways. There are considerable variations of ...
Testosterone is metabolized to various 17-keto steroids through two different pathways. There are considerable variations of ...
The excretion of 17-ketosteroids was reduced by benactyzine and increased by LSD. ...
CRYSTAL STRUCTURE OF MUTANT ENZYME Y32F/Y57F OF KETOSTEROID ISOMERASE FROM PSEUDOMONAS PUTIDA BIOTYPE B ... CRYSTAL STRUCTURE OF MUTANT ENZYME Y32F/Y57F OF KETOSTEROID ISOMERASE FROM PSEUDOMONAS PUTIDA BIOTYPE B Coordinates. PDB Format ... network involving a tyrosine triad in the active site to the structure and function of a highly proficient ketosteroid ...
Testosterone is metabolized to various 17-keto steroids through two different pathways.. The half-life of testosterone ...
Specimen Collection Guides and Resources at Meadville Medical Center | This section includes specimen collection information for the laboratory, microbiology, pathology, and blood bank. Reference materials such as log sheets for reference specimens, instructions for using a lock box, and courier specimen packing lists are also available. Consult separate information for microbiology, pathology, and blood bank specimens on their respective pages.
... whereas C19 17-ketosteroids such as dehydroepiandrosterone (DHEA) and androstendione do not bind so easily. SHBG has a high ...
5-alpha ketosteroid reductase: ... Even species where both mating types can reproduce pay a price for sex ... Jamie Lee Curtis ...
Extreme electric fields power catalysis in the active site of ketosteroid isomerase. Science 2014; 346: 1510-1514 ... Extreme electric fields power catalysis in the active site of ketosteroid isomerase. Science 2014; 346: 1510-1514 ...
17-Ketosteroid Excretion in Men with Gout (1 September, 1957) E. R. Cook, G. D. Kersley, M. Luscombe ...
Delta-5-3-ketosteroid isomerase; Dihydrotestosterone oxidoreductase; HGNC:5217; hydroxysteroid dehydrogenase-1, delta. -3-beta ...
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: 3-ketosteroid Δ1-dehydrogenase; KSTD; KSDH; ... Keywords: 3-ketosteroid D1-dehydrogenase; KSTD; KSDH; AcmB; 1,2-dehydrogenation; cholest-4-en-3-one Δ1-dehydrogenase; enzyme ...
  • Although ketosteroid isomerase (KSI) is a commonly used affinity tag for expression and purification of short peptides, KSI tag needs to be removed with the toxic reagent cyanogen bromide (CNBr). (a-star.edu.sg)
  • Quantitative dissection of hydrogen bond-mediated proton transfer in the ketosteroid isomerase active site. (cornell.edu)
  • We have carried out in-depth interrogations of the proton transfer equilibrium within a hydrogen bond network formed to bound phenols in the active site of ketosteroid isomerase. (cornell.edu)
  • 134. P. Hanoian, P. A. Sigala, D. Herschlag, and S. Hammes-Schiffer, "Hydrogen bonding in the active site of ketosteroid isomerase: Electronic inductive effects and hydrogen bond coupling," Biochemistry 49 , 10339-10348 (2010). (hammes-schiffer-group.org)
  • The enzyme 3 beta-hydroxysteroid dehydrogenase/5-ene-4-ene isomerase (3 beta-HSD) catalyses the oxidation and isomerisation of 5-ene-3 beta-hydroxypregnene and 5-ene-hydroxyandrostene steroid precursors into the corresponding 4-ene-ketosteroids necessary for the formation of all classes of steroid hormones. (embl.de)
  • However, the structure of the ketosteroid isomerase had to be refined in P1 at atomic resolution, although it refines well in C2221 at lower resolution such as 1.5A. (uni-konstanz.de)
  • 5beta-Reduced steroids and human Delta(4)-3-ketosteroid 5beta-reductase (AKR1D1). (medlineplus.gov)
  • The excretion of 17-ketosteroids was reduced by benactyzine and increased by LSD. (erowid.org)
  • Examples of 17-ketosteroids include: Androstenedione Androstanedione Androsterone Dehydroepiandrosterone Epiandrosterone Epietiocholanolone Etiocholanolone 17-Ketosteroids are endogenous steroid hormones. (wikipedia.org)
  • A ketosteroid, or an oxosteroid, is a steroid in which a hydrogen atom has been replaced with a ketone (C=O) group. (wikipedia.org)
  • A 17-ketosteroid is a ketosteroid in which the ketone is located specifically at the C17 position (in the upper right corner of most structure diagrams). (wikipedia.org)
  • Levels of 17-hydroxycorticosteroids and 17-ketosteroids in maternal and cord plasma in term anencephaly. (johnshopkins.edu)
  • 1953 ) Acylation of 17-hydroxy-20-ketosteroids Journal of the American Chemical Society . (academictree.org)
  • Newer tests have superseded 17-ketosteroid testing, and the assay is seldom used now. (medscape.com)
  • This graph shows the total number of publications written about "17-Ketosteroids" by people in this website by year, and whether "17-Ketosteroids" was a major or minor topic of these publications. (rush.edu)
  • 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)
  • 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)
  • 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)
  • The activity of 3 beta-hydroxysteroid dehydrogenase/isomerase (3 beta-HSD), 17-hydroxylase (17-OHase), 17,20-desmolase (17,20D), 17-ketosteroid reductase (17-KSR) and aromatase were measured using a constant amount (50 microM) of 14C-labelled substrates in the presence of varying concentrations of pure ketoconazole. (regrowth.com)
  • The glutamate-histidine substitution prevents a 3-ketosteroid from penetrating the active site so that hydride transfer is directed toward the C3 carbonyl group rather than the Δ(4)-double bond and confers 3β-HSD activity on the 5β-reductase. (anl.gov)
  • The substrate spectrum of N. simplex 3-ketosteroid-Δ 1 -dehydrogenase was expanded in this study with progesterone and its 17α-hydroxylated and 11α,17α-dihydroxylated derivatives, that effectively were 1(2)-dehydrogenated in vivo by the whole cells of the N. simplex VKM Ac-2033D. (biomedcentral.com)
  • A ketosteroid, or an oxosteroid, is a steroid in which a hydrogen atom has been replaced with a ketone (C=O) group. (wikipedia.org)
  • Examples of 17-ketosteroids include: Androstenedione Androstanedione Androsterone Dehydroepiandrosterone Epiandrosterone Epietiocholanolone Etiocholanolone 17-Ketosteroids are endogenous steroid hormones. (wikipedia.org)
  • 17-ketosteroids are substances that form when the body breaks down male steroid sex hormones called androgens and other hormones released by the adrenal glands in males and females, and by the testes in males. (medlineplus.gov)
  • A study by Adriaansen et al suggested that salivary samples of the 17-ketosteroid androstenedione as well as of another steroid, 17-hydroxyprogesterone, can be used to monitor the efficacy of treatment in congenital adrenal hyperplasia. (medscape.com)
  • 6. Human ketosteroid receptors interact with hazardous phthalate plasticizers and their metabolites: an in silico study. (nih.gov)
  • AKR1D1 catalyzes the 5β-reduction of Δ(4)-3-ketosteroids, whereas AKR1C enzymes are hydroxysteroid dehydrogenases (HSDs). (anl.gov)
  • Hammond GL, 1995) whereas C19 17-ketosteroids such as dehydroepiandrosterone (DHEA) and androstendione do not bind so easily. (cdc.gov)
  • An important point is not vigorous at birth, vitamin d - hydroxycholecalciferol - oh pregnenolone, desmolase dhea - ol dehydrogenase urinary ketosteroids dhea elevated plasma bicarbonate concentration or carrying capacity is maintained. (elastizell.com)
  • The genome sequence of R.pyridinivorans strain AK37 has identified several key enzymes involved in the six pathways of monocyclic aromatic compound biodegradation: protocatechuate 3,4-dioxygenase, benzoate 1,2-dioxygenase, 3-ketosteroid-9α-hydroxylase, 3-ketosteroid-σ-dehydrogenase, and so on. (kenyon.edu)
  • Merriam-Webster.com Dictionary , Merriam-Webster, https://www.merriam-webster.com/dictionary/ketosteroid. (merriam-webster.com)
  • These hormones include glucocorticoids, mineralocorticoids and 17-ketosteroids. (kschmidtobgyn.com)
  • The strain of Nocardioides simplex VKM Ac-2033D is well known mainly for its superior 3-ketosteroid Δ 1 -dehydrogenase activity towards various 3-oxosteroids and other important reactions of sterol degradation. (biomedcentral.com)
  • Superior 3-ketosteroid-Δ 1 -dehydrogenase activity of N. simplex VKM Ac-2033D is due to the kstDs redundancy in the genome, with the highest expression level of the gene KR76_27125 orthologous to kstD2, in response to cortisone 21-acetate. (biomedcentral.com)
  • Search Medline for 3-ketosteroid 9alpha-hydroxylase . (ethz.ch)