Hydrolysis of dehydroepiandrosterone sulphate by human placental steroid 3beta-sulphatase in [18O] water.
Ontology highlight
ABSTRACT:
SUBMITTER: Logan GG
PROVIDER: S-EPMC1184956 | biostudies-other | 1969 Oct
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Steroid sulphatase (STS) is one of the steroid-metabolising enzymes involved in desulphating inactive steroid sulphates and oestrogen sulphotransferase (EST) sulphates active oestrogen. The roles of both STS and EST have not been examined in oestrogen-dependent non-small-cell lung cancer (NSCLC).We evaluated the immunoreactivity of STS and EST in NSCLC cases using immunohistochemistry. The function of STS and EST was further demonstrated using NSCLC cell lines.The immunoreactivity of STS and EST was detected in 49.5% and 27.8% of NSCLC cases, respectively. The immunoreactivity of STS was significantly higher in female adenocarcinoma cases. The STS-positive NSCLCs were also significantly correlated in an inversed manner with tumour size and cell proliferation and tended to be associated with better clinical outcome. However, the immunoreactivity of EST was significantly correlated with intracellular oestradiol concentration. Results of in vitro analysis demonstrated that oestrone sulphate (E1-S) induced and pregnenolone sulphate (Preg-S) inhibited the proliferation in STS-expressing cell lines. The inhibition by Preg-S was reversed by a specific progesterone receptor blocker. Simultaneous addition of E1-S and Preg-S significantly suppressed the proliferation.In NSCLC patients, STS is considered a good prognostic factor. Results of our present study also indicated the benefits of potential progesterone therapy for NSCLC patients.
| S-EPMC3629433 | biostudies-literature
Project description:Placental steroid sulphatase deficiency (SSD) is an X-linked inborn error of metabolism. Congenital X-linked ichthyosis (XLI) is a genetic disorder of keratinisation caused by steroid sulphatase (STS) deficiency, which results in a scaling skin condition in male infants shortly after birth. It may be associated with failed induction of labor and prolonged labor leading to cesarean delivery due to 'cervical dystocia'. We present two cases of congenital ichthyosis. Thorough counselling of women with a previously affected pregnancy during the antenatal period should include discussion about mode of delivery and a critical review of the complexities of prenatal diagnosis in this condition. We propose a clinical management pathway to offer women with a previous pregnancy affected by this rare condition. SIMILAR CASES PUBLISHED: Less than 50 cases reported.
| S-EPMC6302985 | biostudies-other
Project description:Derivatives of 3beta-amino-5-cholestene (3beta-cholesterylamine) are of substantial interest as cellular probes and have potential medicinal applications. However, existing syntheses of 3beta-amino-5-cholestene are of limited preparative utility. We report here a practical method for the stereoselective preparation of 3beta-amino-5-cholestene, 3beta-chloro-5-cholestene, 3beta-bromo-5-cholestene, and 3beta-iodo-5-cholestene from inexpensive cholesterol. A sequential i-steroid/retro-i-steroid rearrangement promoted by boron trifluoride etherate and trimethylsilyl azide converted cholest-5-en-3beta-ol methanesulfonate to 3beta-azido-cholest-5-ene with retention of configuration in 93% yield.
| S-EPMC2651230 | biostudies-literature
Project description:1. A simple method for the extraction of 17-oxo steroid sulphates of plasma is described; glucosiduronates and orthophosphates are extracted, but to a smaller extent. 2. Four methods of analyses of the extracts are given and are relatively simple. Three of these are specific for steroid sulphates and two measure the sulphate conjugates directly. 3. Values for dehydroepiandrosterone sulphate and androsterone sulphate concentrations of normal and pathological plasmas are given.
| S-EPMC1215184 | biostudies-other
Project description:Kinetic parameters (Km and kcat.) of the two major forms (A and B) and a minor form (C) of human liver N-acetylglucosamine-6-sulphate sulphatase [Freeman, Clements & Hopwood (1987) Biochem. J. 246, 347-354] were determined with a variety of substrates matching structural aspects of the physiological substrates in vivo, namely heparin, heparan sulphate and keratan sulphate. Enzyme activity is highly specific towards glucosamine 6-sulphate or glucose 6-sulphate residues. More structurally complex substrates, in which several aspects of the aglycone structure of the natural substrate were maintained, are hydrolysed with catalytic efficiencies up to 3900 times above that observed for the monosaccharide substrate N-acetylglucosamine 6-sulphate. Forms A and B both desulphate substrates derived from keratan sulphate and heparin. Aglycone structures that influence substrate binding and/or enzyme activity were penultimate-residue 6-carboxy and 2-sulphate ester groups for heparin-derived substrates and penultimate-residue 6-sulphate ester groups for keratan sulphate-derived substrates. The 4-hydroxy group of the N-acetylglucosamine 6-sulphate or the 2-sulphaminoglucosamine 6-sulphate under enzymic attack is involved in the catalytic mechanism. The presence of a 2-amino group in place of a 2-acetamido or a 2-sulphoamino group considerably decreases the catalytic efficiency of the sulphatase, particularly in the absence of a penultimate-aglycone-residue 6-carboxy group. Both forms A and B are exo-enzymes, since activity towards internal sulphate ester bonds was not observed. The effect of incubation pH on enzyme activity towards the variety of substrates evaluated was complex and dependent on substrate aglycone structure. The presence of aglycone 2-sulphate ester, 6-carboxy group and 6-sulphate ester groups on the glucosamine 6-sulphate residue under attack considerably affects the pH response. Sulphate and phosphate ions are potent inhibitors of enzyme activity.
| S-EPMC1148284 | biostudies-other
Project description:1. The properties of enzyme activities hydrolysing the sulphate esters of dehydroepiandrosterone, oestrone and p-nitrophenol are reported. The preparation studied was obtained from the microsomal fraction of human placenta by ultrasonic treatment and addition of Triton X-100. 2. The behaviour of the preparation during sedimentation at 105000g and attempts at purification indicated that the activities were particulate. Electron microscopy demonstrated the rupture of vesicular structures approx. 0.5mu in diameter concurrent with the release of activity. 3. The three activities were always associated throughout repeated attempts at separation by sucrose-density-gradient centrifugation and Sephadex-gel filtration. On the basis of kinetic studies, stability studies and treatment with butanol and ribonuclease it was concluded that a separate enzyme is responsible for each of the three activities. Widely varying plots of activity as a function of pH were consistent with this conclusion. 4. On the basis of sensitivity of the enzymes hydrolysing dehydroepiandrosterone sulphate and oestrone sulphate to ribonuclease and sensitivity of all three enzymes to lipase, it was concluded that the three enzymes are bound to a particle containing lipid and RNA. Enzymic activity is dependent on structural integrity of the particle. 5. A spectrophotometric method for the assay of oestrone sulphate hydrolysis is described. 6. Hydrolysis of nitrocatechol sulphate by human placenta under conditions described for arylsulphatases A and B is reported.
| S-EPMC1198294 | biostudies-other
Project description:The chemical syntheses of the 3-sulphates of 16 alpha-acetoxy-, 16 alpha-hydroxy- and 16 beta-hydroxy-dehydroepiandrosterone as their triethylammonium salts are described preparatory to studies of the metabolism of [7 alpha-3 H]dehydroepiandrosterone sulphate by homogenates of human foetal liver. Five main radioactive products of the incubation were separated by partition chromatography on a Celite column. Two were identified as 16 alpha-and 16 beta-hydroxydehydroepiandrosterone 3-sulphates by crystallization to constant specific radioactivity before and after solvolysis. The yields of the conversion to the two epimers were 24.4% (16 alpha) and 1.8% (16 beta).
| S-EPMC1163763 | biostudies-other
Project description:Human N-acetylglucosamine-6-sulphate sulphatase was purified at least 50,000-fold to homogeneity in 78% yield from liver with a simple three-step four-column procedure, which consists of a concanavalin A-Sepharose/Blue A-agarose coupled step, chromatofocusing and Cu2+-chelating Sepharose chromatography. In all, four forms were isolated and partially characterized. Forms A and B, both with a pI greater than 9.5 and representing 30% and 60% respectively of the recovered enzyme activity, were separated by hydroxyapatite chromatography of the enzyme preparation obtained from the Cu2+-chelating Sepharose step. Both forms A and B had native molecular masses of 75 kDa. When analysed by SDS/polyacrylamide-gel electrophoresis, form A consists of a single polypeptide of molecular mass 78 kDa, whereas form B contained 48 kDa and 32 kDa polypeptide subunits. Neither form A nor form B was taken up from the culture medium into cultured human skin fibroblasts. The two other forms (C and D), with pI values of 5.8 and 5.4 respectively, represented approx. 7% and 3% of the total recovered enzyme activity. The native molecular masses of forms C and D were 94 kDa and approx. 75 kDa respectively. Form C contained three polypeptides with molecular masses of 48, 45 and 32 kDa. N-Acetylglucosamine-6-sulphate sulphatase activity was measured with a radiolabelled disaccharide substrate derived from heparin. The development of this substrate enabled the isolation and characterization of N-acetylglucosamine-6-sulphate sulphatase to proceed efficiently. Forms A, B and C had pH optima of 5.0, Km values of 11.7, 14.2 and 11.1 microM respectively and Vmax. values of 105, 60 and 53 nmol/min per mg of protein respectively. The molecular basis of the multiple forms of this sulphatase is not known. It is postulated that the differences in structure and properties of the four enzyme forms are due to differences in the state of processing of a large subunit.
| S-EPMC1148283 | biostudies-other
Project description:1. N-Acetylgalactosamine 6-sulphate sulphatase was purified about 20000-fold from the soluble extract of human placenta with N-acetylgalactosamine 6-sulphate-glucuronic acid-N-acetyl[1-(3)H]galactosaminitol 6-sulphate as substrate in the activity assay. The enzyme appears to be a glycoprotein with a mol.wt. of about 100000 as determined by gel filtration. On gel electrophoresis in the presence of sodium dodecyl sulphate the major protein band had a mol.wt. of 78000. Variable charge heterogeneity was observed in several enzyme preparations. 2. The purified enzyme released up to one sulphate molecule from the disulphated trisaccharide. It was active towards N-acetylgalactosamine 6-sulphate and exhibited no measurable N-acetylglucosamine 6-sulphate sulphatase or any other known lysosomal sulphatase activity. Hydrolysis of [1-(3)H]galactitol 6-sulphate was achieved by incubation neither with a crude nor with a purified enzyme preparation. Chondroitin 6-sulphate and keratan sulphate, as well as heparin and heparan sulphate, served as competitive inhibitors of the enzyme. 3. Purified N-acetylgalactosamine 6-sulphate sulphatase activity was optimal at pH4.9 and 4.4 when assayed in 0.02m-sodium acetate buffer and at pH4.2 and 5.2 in 0.1m-sodium acetate buffer. A single pH-optimum at pH4.8 was observed for the crude enzyme and for the purified enzyme after mild periodate treatment. The sulphatase activity was inhibited by a variety of anions and cations and activated by thiol-specific and thiol reagents.
| S-EPMC1161122 | biostudies-other
Project description:OBJECTIVE:Little is known about the relationships of dietary factors, physical activity and sedentary behaviour to dehydroepiandrosterone sulphate (DHEAS) and insulin-like growth factor-1 (IGF-1) concentrations among prepubertal children. Therefore, we studied the associations of these lifestyle factors with serum DHEAS and IGF-1 in children. DESIGN AND SUBJECTS:Cross-sectional analysis of a population sample of 431 prepubertal children aged 6-9 years. MEASUREMENTS:Assessment of dietary factors by food records and physical activity and sedentary behaviour by a combined heart rate and movement monitor and a questionnaire. Measurement of serum DHEAS and IGF-1. RESULTS:Consumption of low-fibre grain products (standardized regression coefficient ? = .118, P = .017) and intake of vegetable protein (? = .100, P = .045) was positively and consumption of sugar-sweetened beverages (? = -.117, P = .018) was inversely associated with DHEAS after adjustment for sex, age and body fat percentage. Energy intake (? = .160, P = .001) was positively associated with IGF-1 adjusting for sex, age and body fat percentage. Vigorous physical activity was inversely associated with DHEAS after adjustment for sex and age (? = -.120, P = .027), and total (? = -.137, P = .007), moderate (? = -.130, P = .012), vigorous (? = -.136, P = .011) and moderate to vigorous physical activity (? = -.160, P = .003) were inversely and total sedentary behaviour (? = .151, P = .003) was positively associated with IGF-1 adjusting for sex and age. None of physical activity measures was associated with DHEAS or IGF-1 after additional adjustment for body fat percentage. CONCLUSIONS:Lifestyle factors have weak and moderate associations with biochemical markers of adrenarche in prepubertal children. These associations indicate body fat independent and dependent influences of diet and physical activity, respectively.
| S-EPMC6195184 | biostudies-literature