Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.6.1 (sulfatase)
3,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Characteristics and activities of estrone sulfate (E1S) and dehydroepiandrosterone sulfate (DHAS) sulfatases were studied in epithelium and stroma of benign hyperplastic tissues from human prostates. Tissues were obtained by suprapubic prostatectomy, and epithelium and stroma were separated mechanically by standard techniques. The assay procedure comprised homogenization in Tris-buffer, incubation of the homogenate with [3H]E1S or [3H]DHAS, separation of free steroids from nonhydrolyzed steroid sulfates by extraction with ether, and their final quantification by LSC. The main results were: (1) The pH-optimum of the sulfatase was found at pH 7.0. (2) The highest specific sulfatase activity was found in the epithelium and was associated with its nuclear fraction. (3) Michaelis-Menten constants Km (microM) were 8.7 +/- 1.4 (7) and 4.3 +/- 0.8 (5), maximum velocity rates Vmax (nmol/h x mgDNA) were 47.4 +/- 8.8 (7) and 8.4 +/- 1.5 (5) for E1S and DHAS, respectively (means +/- SEM (n]. (4) The enzymatic cleavage of E1-sulfate was competitively inhibited by DHA-sulfate and vice versa with inhibition constants Ki (microM) of 4.0 +/- 0.5 (2) for E1S and 2.7 +/- 0.4 (2) for DHAS. On the basis of these findings, possible roles of steroid sulfate-sulfatases in forming precursors of active androgens and estrogens from the high amounts of E1S and DHAS in blood are discussed.
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PMID:Steroid sulfate sulfatase in human benign prostatic hyperplasia: characterization and quantification of the enzyme in epithelium and stroma. 247 73

Steroid sulfatase (STS) activity was studied in the Long-Evans rat testis. The rate of dehydroepiandrosterone sulfate (DHA-S) hydrolysis determined in whole testis homogenates was low compared to that of the corresponding microsomal fractions, which was, in contrast, as high as that expressed in homogenates from purified Leydig cells. Such an increment in STS activity between total homogenates and the corresponding microsomes was not observed for the seminiferous tubules. The STS affinity reported for total testicular microsomes (Km = 3.47 +/- 0.54 microM; mean +/- SEM) was of the same magnitude as that previously reported for Leydig cells, but was about 3 times higher than that measured for whole testis homogenate (Km = 10.11 +/- 0.92 microM). In vivo hCG treatment decreased the STS affinity in total testicular microsomes without affecting this kinetic parameter in whole testis homogenate. These data suggest that the steroid sulfatase expressed in total testicular microsomes (activity and regulation by hCG) could be considered as a good index of Leydig cell STS activity.
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PMID:Steroid sulfatase activity in homogenates, microsomes and purified Leydig cells from adult rat testis. 253 91

One-third of the cases of breast cancer in postmenopausal women are hormone-dependent and the lesions regress upon treatment with antiestrogens or inhibition of estrogen biosynthesis. In these patients, estrogens are synthesized in extraglandular tissues from adrenal precursors and re-enter plasma to produce estrone levels of 52 +/- 6.5 pg/ml (mean +/- SEM) and estradiol concentrations of 13.1 +/- 0.7 pg/ml. However, the fact that the levels of estrogen in breast tumor tissue are an order of magnitude higher than plasma levels suggested the possibility of in situ estrogen production. To address this possibility, we measured several enzymes involved in estradiol biosynthesis in human tumors. Forty-eight of 61 tumors contained aromatase (estrogen synthetase) activity ranging from 5-80 pg/gm protein per hour. By comparison, the levels of estrone sulfatase were 10(6) higher, ranging from 0.8-125 micrograms/gm protein per hour. Because the sulfatase enzyme was of lower affinity (i.e., Km = 27 microM) than that of aromatase (i.e., 0.027 microM), the amount of estrogen formed under conditions of similar substrate concentrations was compared and found to be 10-fold higher via the sulfatase enzyme. In 41 additional tumors, the 17 beta-hydroxysteroid dehydrogenase enzyme, catalyzing the conversion of estrone to estradiol, was uniformly present. To test the biologic relevance of the estrone sulfate to estrone to estradiol pathway, estrogen-dependent nitrosomethylurea rat mammary tumors were grown in soft agar in the presence of estrone sulfate. Concentrations of estrone sulfate of 10(-6) microM significantly (p less than 0.01) stimulated colony formation in this system in which 75.5-98.6% of estrone sulfate was converted to estrone and 0.2 to 6% to estradiol. These data support the hypothesis that mammary carcinomas can synthesize estradiol in situ from circulating estrogen precursor and that local conversion is biologically important. On the basis of comparative data, the estrone sulfate to estrone to estradiol pathway is quantitatively more important than that involving androstenedione to estrone to estradiol.
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PMID:Enzymatic control of estrogen production in human breast cancer: relative significance of aromatase versus sulfatase pathways. 352 46

The degree of tyrosine sulfation and the distribution between gastrin-17- and gastrin-34-like immunoreactivity (LI) were studied in the antra of ten mammalian species. Specific radioimmunoassays, gel-, and ion-exchange chromatography as well as enzymatic cleavage with trypsin and arylsulfatase were used. The percentage of sulfation varied from 24.4 +/- 4.2 (mean +/- SEM) in dogs to 80.1 +/- 2.6 in sheep, 46.8 +/- 3.3 in humans, 50.1 +/- 3.2 in cows, 55.9 +/- 2.3 in rats, 57.4 +/- 3.1 in pigs, 61.3 +/- 2.2 in guinea pigs, 64.1 +/- 4.7 in cats, 64.8 +/- 2.1 in mice and 68.2 +/- 2.8 in rabbits. Gastrin-34-LI in antral extracts could be converted to gastrin-17-LI by trypsin in all species. Five percent of antral gastrins eluted as gastrin-34-LI in all species. We conclude that while the ratio of gastrin-34-LI to gastrin-17-LI varies little in mammals, large differences occur in the degree of sulfation.
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PMID:Species variation in the tyrosine sulfation of mammalian gastrins. 398 36

It is well recognized that in the fetal adrenal cortex, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity is lower and in fetal tissues, steroid sulfokinase (SK) is higher than in the adult. In order to clarify a part of the development processes of the adrenal cortex or steroidgenesis in humans, a combined radioimmunoassay (RIA) method to estimate serum 17 alpha-hydroxypregnenolone (17-OH-delta 5 P), 17 alpha-hydroxypregnenolone sulfate (17-OH-delta 5 P-S) and 17 alpha-hydroxyprogesterone (17-OH-delta 4P) was devised. The method consisted of the following procedures: 1) diethyl ether extraction and chromatographic separation of unconjugated steroids (17-OH-delta 5P and 17-OH-delta 4P), 2) enzymatic hydrolysis of 17-OH-delta 5P-S using the residue of diethyl ether extraction for a material, 3) diethyl ether extraction and chromatographic purification of hydrolyzed 17-OH-delta 5P-S, and 4) RIAs for 17-OH-delta 5-P to estimate 17-OH-delta 5P and 17-OH-delta 5P-S concentration, and for 17-OH-delta 4P. Extracted 17-OH-delta 5P was well separated from 17-OH-delta 4P by Sephadex LH-20 microcolumn chromatography, using a benzene/methanol = 95/5 (v/v) solvent as a mobile phase. Several procedures for hydrolysis or solvolysis of 17-OH-delta 5P-S were compared using available tritiated delta 5-3 beta-hydroxysteroids including dehydroepiandrosterone (DHA), DHA sulfate (DHA-S) and 17-OH-delta 5P, and it was found that the most suitable method was an enzymatic hydrolysis by arylsulfatase from Helix Pomatia in an appropriate condition in which the percent hydrolysis was 92.9 +/- 1.2 (mean +/- SEM)%. The final percent recoveries were 88.7 +/- 1.2% in 17-OH-delta 4P, 90.7 +/- 1.4% in 17-OH-delta 5P and 78.1 +/- 2.1% in 17-OH-delta 5P-S, respectively. A suitable antiserum and its final dilution titer for RIA of 17-OH-delta 5P (hydrolyzed 17-OH-delta 5P-S also) was 1:12,000 dilution of anti-17-OH-delta 5P-3-succinate-BSA serum. An anti-7-oxo-17-OH-delta 5P-7-carboxymethyloxime-BSA serum was considered to be unsuitable for the measurement of hydrolyzed 17-OH-delta 5-P-S, presumably because of a significant cross-reactivity with a large amount of unknown steroid sulfates simultaneously hydrolyzed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[A combined radioimmunoassay method for the determination of 17 alpha-hydroxypregnenolone, 17 alpha-hydroxypregnenolone sulfate and 17 alpha-hydroxyprogesterone in human blood]. 405 6

The concentrations of free and total normetanephrine (NMN) were determined in the plasma of normotensives and patients with primary hypertension and pheochromocytoma. NMN values were measured in the cerebrospinal fluid (CSF) of patients. Free and conjugated NMN, the latter after acid hydrolysis, were assayed using S-adenosylmethionine in the presence of phenylethanolamine-N-methyltransferase to form labeled metanephrine. The conjugates of NMN were present in plasma as sulfates principally, as they were also liberated with arylsulfatase. Free and conjugated NMN levels were 117 +/- 10 and 1417 +/- 109 ng/liter, respectively in plasma of normotensives. The mean ratio of the content of conjugated to free NMN was 14.9 +/- 1.8 (mean +/- SEM). The contents of free and conjugated NMN were 155 +/- 33 and 1670 +/- 320 ng/liter in primary hypertensives, respectively, and the ratio of conjugated to free NMN was 18.5 +/- 3.3. These values did not differ significantly from those in normotensives. The contents of free and total NMN in the plasma of patients with pheochromocytoma were 50- to 60-fold greater than values in normotensive and primary hypertensives. The mean ratio of conjugated to free NMN in the plasma of patients with pheochromocytoma was similar to those in normotensives and primary hypertensives. The contents of free and conjugated NMN in the CSF of patients with pheochromocytoma exceeded those in primary hypertensives (P less than 0.01 and P less than 0.001). Further, the ratio of conjugated to free NMN in CSF was increased in patients with pheochromocytoma (33.9 +/- 8.1) compared to that primary hypertensives (8.3 +/- 2.3; P less than 0.001). The measurement of NMN in plasma and CSF may help characterize sympathetic nerve tone in patients with primary hypertension to elucidate the pathophysiology of the elevated blood pressure.
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PMID:The relationships of free to conjugated normetanephrine in plasma and spinal fluid of hypertensive patients. 707 10

To investigate the changes in the serum androgen concentrations and the Free Androgen Index (FAI) in women during danazol therapy, we measured the serum concentrations of adrenal steroids and danazol metabolites, and then examined the effects of danazol metabolites on assays for serum androgens. Thirteen women who had endometriosis were treated with danazol (300 or 400 mg/day) for 8 to 16 weeks. Blood samples were taken before, during, and after the medication. During the danazol therapy, serum testosterone (T), cortisol (F), and sex-hormone binding globulin (SHBG) significantly decreased (P < 0.05); but serum dehydroepiandrosterone-sulfate (DHEAS) and FAI increased (P < 0.05). The serum concentrations of danazol metabolites were: danazol, 209.0 +/- 28.3 (ng/mL, mean +/- SEM); delta 1-2-hydroxymethyl ethisterone, 114.4 +/- 8.4; and 2-hydroxymethyl ethisterone, 660.0 +/- 54.2. There was considerable cross-reaction between danazol metabolites and androgens [T, androstenedione (A), and dehydroepiandrosterone (DHEA)] in the direct assays. As for the ratios of adrenal steroids in serum, the DHEAS/F, DHEAS/DHEA, and 11-deoxycortisol (S)/F ratios increased (P < 0.05). We conclude that the increase in FAI and DHEAS represents increased native androgenic activity with danazol, and the changes in adrenal steroid ratios in serum indicate the inhibition of 11 beta-hydroxylase and sulfatase activities during danazol therapy.
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PMID:Adrenal steroids in serum during danazol therapy, taking into account cross-reactions between danazol metabolites and serum androgens. 795 34

To elucidate whether increased plasma levels of free dopamine (F-DA) after exercise are due to deconjugation of sulfoconjugated (S-) DA in plasma, we compared the changes in plasma F- and S- DA, as well as changes in both the S- and F- forms of epinephrine (E) and norepinephrine (NE), after running a half-marathon. Free catecholamines (F-CAs) were measured by automated high-performance liquid chromatography (HPLC). Total (F+S) CAs were determined using an efficient deconjugation method as follows; 1200 microliters plasma was incubated with 152 mU arylsulfatase (AS) for 30 min at pH 7.6. The plasma levels of F-CA (pg/ml) (mean +/- SEM) all increased significantly (p < 0.01) after the half-marathon; i.e., F-DA increased from 13.3 +/- 5.7 to 176.3 +/- 32.2; F-E from 58.0 +/- 12.3 to 764.3 +/- 136.4; F-NE from 246.6 +/- 15.2 to 3082.0 +/- 690.3. OF S-CAs, S-E (from 127.8 +/- 26.0 to 1218.2 +/- 190.8) and S-NE (from 717.1 +/- 61.6 to 5586.9 +/- 761.9) also increased, but, in contrast, among the S-CAs, only the increase in S-DA (from 5324.9 +/- 1967.3 to 7359.6 +/- 1627.9) was not statistically significant. Sulfoconjugation may play an important role in inactivating F-DA as well as F-NE and -E, that are released into plasma in response to vigorous exercise. Thus, plasma F-DA is unlikely to be derived through deconjugation of plasma S-DA.
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PMID:Plasma free and sulfoconjugated dopamine before and after a half-marathon. 852 50

This report concerns the evaluation of various estrogens, estrone (El), estradiol (E2), and estrone sulfate (E1S), as well as E1S-sulfatase and aromatase activities in pre- and postmenopausal women with breast cancer. The levels (in picomoles per g; mean +/- SEM) of the various estrogens in the breast tissue from premenopausal patients (n = 11) are: El, 1.4 +/- 0.5; E2, 1.2 +/- 0.6; and E1S, 1.2 +/- 0.3. In postmenopausal patients (n = 23), the values are, respectively, 1.0 +/- 0.4, 1.4 +/- 0.7, and 3.3 +/- 1.9. These concentrations of estrogens in the tumors of postmenopausal patients are significantly higher than those found in plasma. The activity of E1S-sulfatase in both pre- and postmenopausal patients was 50-200 times higher than that of aromatase. E1S-sulfatase and aromatase activities are significantly higher in post-menopausal than in cycling patients. It is concluded that despite the low levels of circulating estrogens in postmenopausal patients, the tissue concentrations of these steroids are several-fold higher than those in plasma, suggesting tumor accumulation of these estrogens. The physiopathology and clinical significance of these high levels of the various estrogens (E1, E2, and E1S) as well as sulfatase and aromatase activities in postmenopausal patients with breast cancer is yet to be explored.
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PMID:Concentrations of estrone, estradiol, and estrone sulfate and evaluation of sulfatase and aromatase activities in pre- and postmenopausal breast cancer patients. 863 51

Enteric bacteria have been postulated to have a role in thyroid economy by promoting the hydrolysis of thyroid hormone conjugates of biliary origin, thus permitting the absorption and recycling of thyroxine (T4) and triiodothyronine (T3). An enterohepatic circulation of T3 might be more pronounced under conditions in which type I iodothyronine deiodinase activity (5'D-I) is inhibited, because this augments the accumulation of T3 sulfate conjugates in bile. This potential of increased gut reabsorption of T3 might explain, at least in part, the failure of serum T3 values to decrease appreciably when marked reductions in peripheral 5'D-I activity are induced by selenium deficiency or 6-anilino-2-thiouracil (ATU) administration. Thus, studies were performed to determine the effect of intestinal decontamination, in the absence and in the presence of 5'D-I inhibition, on plasma T4 and T3 concentrations. Groups of adult male rats received either enteric antibiotics or no antibiotics for 12 days and then, in half of the rats in each group, treatment for 10 days with ATU, a 5'D-I inhibitor that does not affect thyroid hormone synthesis. The activity of intestinal arylsulfatase and arylsulfotransferase, enzymes that catalyze hydrolysis of thyroid hormone conjugates, was reduced markedly by approximately 87% in rats that received antibiotics, regardless of whether or not they also received ATU. The ATU treatment markedly inhibited liver 5'D-I activity in antibiotic-treated as well as in non-antibiotic-treated rats (control = 399 +/- 32 U/mg protein (mean +/- SEM); ATU = 152 +/- 17: antibiotics = 351 +/- 29; antibiotics + ATU = 130 +/- 10; p < 0.01) and significantly increased plasma T4 and T3 sulfate (T4S, T3S) concentrations (control: T4S = 2.8 +/- 0.4 and T3S = 6.7 +/- 1.3 ng/dl; ATU: T4S = 6.2 +/- 1.4 and T3S = 10.6 +/- 2.1 ng/dl; antibiotics: T4S = 1.8 +/- 0.2 and T3S = 3.6 +/- 1.0 ng/dl; antibiotics + ATU: T4S = 6.8 +/- 0.7 and T3S = 9.7 +/- 1.8 ng/dl; p < 0.05). The ATU treatment was associated with a significant increase in plasma T4 and rT3 concentrations but did not affect plasma T3 concentrations, and intestinal decontamination did not alter these ATU-associated effects on circulating thyroid hormones. These results suggest that anaerobic enteric bacteria in the rat do not have an important role in recycling of thyroid hormones, either under normal conditions or in circumstances where 5'D-I activity is markedly reduced, and that increased gut absorption of T3 from T3S cannot explain the near-normal serum T3 values found when peripheral 5'D-I activity is markedly decreased.
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PMID:Serum iodothyronine concentrations in intestinally decontaminated rats treated with a 5'-deiodinase type I inhibitor 6-anilino-2-thiouracil. 864 Mar 7


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