STUDIES ON 17β-HYDROXYSTEROID DEHYDROGENASE IN HUMAN ENDOMETRIUM AND ENDOMETRIAL CARCINOMA

1975 ◽  
Vol 80 (2) ◽  
pp. 355-364 ◽  
Author(s):  
K. Pollow ◽  
H. Lübbert ◽  
B. Pollow
Keyword(s):  
Endometrial Carcinoma ◽  
Ammonium Sulphate ◽  
Isoelectric Focusing ◽  
Hydroxysteroid Dehydrogenase ◽  
Maximal Velocity ◽  
Optimum Temperature ◽  
Ammonium Sulphate Precipitation ◽  
Optimum Ph ◽  
Triton X ◽  
Secretory Endometrium

ABSTRACT Microsomal 17β-hydroxysteroid dehydrogenase obtained from the human secretory endometrium (17β-HSD) was solubilized with triton X-100. A 4-fold purification was achieved by ammonium sulphate precipitation and isoelectric focusing. In the presence of glycerol the partially purified enzyme was stable at 4°C for at least 48 h. Using crude microsomes, the conversion of oestradiol to oestrone was linear with time and with the concentration of protein. The optimum temperature was approximately 40°C and the optimum pH 9.4. For the reduction of oestrone the optimum pH was 6.5. With NAD, oestradiol was oxidized approximately three times more rapidly than with NADP. Km-values for oestradiol were nearly the same in endometrial carcinoma and in proliferative and secretory endometrium (i. e. approximately 3 × 10−6 m). The maximal velocity was highest in secretory endometrium. Testosterone and androstenedione could also serve as substrates but they were interconverted more slowly than oestradiol and oestrone. Sulphhydryl groups were shown to be essential for catalysis.

STUDIES ON 17β-HYDROXYSTEROID DEHYDROGENASE IN HUMAN ENDOMETRIUM AND ENDOMETRIAL CARCINOMA

1975 ◽  
Vol 79 (1) ◽  
pp. 146-156 ◽  
Author(s):  
K. Pollow ◽  
H. Lübbert ◽  
R. Jeske ◽  
B. Pollow
Keyword(s):  
Substrate Specificity ◽  
Endometrial Carcinoma ◽  
Hydroxysteroid Dehydrogenase ◽  
Maximal Velocity ◽  
Optimum Temperature ◽  
Optimum Ph ◽  
Cold Sensitive ◽  
Cold Inactivation ◽  
Secretory Endometrium ◽  
Optimal Ph

ABSTRACT Kinetic parameters, substrate specificity and stability of a cytoplasmic 17β-hydroxysteroid dehydrogenase of human secretory endometrium were studied. Using oestradiol as substrate, oestrone formation was found to be linear with time and the concentration of protein. The optimum temperature was 40°C and the optimum pH 9.5. For the reduction of oestrone the optimal pH was 6. With NADP the maximal velocity was about 1/3 of that with NAD (0.23 nmoles/mg protein/10 min). The Km for oestradiol was 3.3 × 10−6 m. Testosterone and androstenedione also served as substrates but they were interconverted more slowly than oestradiol and oestrone. Sulphhydryl groups were shown to be essential for catalysis. The enzyme is cold sensitive but cold inactivation can be reduced by NAD, NADP, oestradiol or glycerol.

Anreicherung und Charakterisierung einer „Transhydrogenase-Aktivität“ und der 17 β-Hydroxysteroid-Oxidoreduktase aus der Cytoplasma-Fraktion der Leber von weiblichen Ratten / The Enrichment and Characterisation of Cytoplasmatic “Transhydrogenase-activity” and 17 β-hydroxysteroid-oxidoreductase from Rat Liver

1972 ◽  
Vol 27 (8) ◽  
pp. 981-988
Author(s):  
Kunhard Pollow ◽  
Barbara Pollow
Keyword(s):  
Molecular Weight ◽  
Ammonium Sulphate ◽  
Rat Liver ◽  
Isoelectric Focusing ◽  
Isoelectric Point ◽  
Column Chromatography ◽  
Enzymatic Activities ◽  
Kinetic Constants ◽  
Gel Chromatography ◽  
Ammonium Sulphate Precipitation

The cytoplasmatic fraction of rat liver contains both 17 β-hydroxysteroid-oxidoreductase and a “transhydrogenase-activity”, which catalyses the transfer of hydrogen from the 17 β-position of estradiol-17 β to the 17-position of 4-androstene-3,17-dione. The 17 β-hydroxysteroid-oxidoreductase was purified 718-fold and the “transhydrogenase-activity” 264-fold by ammonium sulphate precipitation, gel chromatography with Sephadex G-200, column chromatography on DEAE-Sephadex and isoelectric focusing. The two enzymic activities could not be separated. The characteristics of the two enzymatic activities give some evidence that the “transhydrogenase-activity” is identical with the already known 17 β-hydroxysteroid-oxidoreductase.Isoelectric focusing of the chromatographycally enriched 17 β-enzyme gave an isoelectric point at 5,2. The 17 β-enzyme has a molecular weight of 62 — 65 000 as determined by mobility on Sephadex G-200 superfine.The kinetic constants for both the 17 β-enzyme and the “transhydrogenase-activity” were determined.

Meta-Methylation of Flavonol Rings A (8-) and B (3'-) Is Catalysed by Two Distinct O-Methyltransferases in Lotus corniculatus

1983 ◽  
Vol 38 (5-6) ◽  
pp. 413-417 ◽  
Author(s):  
Maurice Jay ◽  
Vincenzo De Luca ◽  
Ragai Ibrahim
Keyword(s):  
Ammonium Sulphate ◽  
Biochemical Markers ◽  
Flower Colour ◽  
Lotus Corniculatus ◽  
The Other ◽  
Flower Buds ◽  
Ph Optimum ◽  
Genetic Studies ◽  
Ammonium Sulphate Precipitation ◽  
Optimum Ph

Two O-methyltransferases specific for flavonol rings A and B were isolated from young flower buds of Lotus corniculatus. They were partially purified by ammonium sulphate precipitation and successive chromatography on Sephadex G-100 and Polybuffer ion exchanger. One enzyme focused at pI 5.5 and catalysed the O-methylation of position 8 of flavonols with a pH optimum of 8.1. The other enzyme had a pi of 5.1 and preferentially attacked position 3' at an optimum pH of 7.7. The methylated products of both enzymes seem to contribute to the flower colour of Lotus and may be used as biochemical markers in genetic studies of this genus.

scholarly journals AKTIVITAS AMILASE, LIPASE DAN PROTEASE DARI CACING Peryonix excavatus

Molekul ◽  
2009 ◽  
Vol 4 (2) ◽  
pp. 115
Author(s):  
Ari Asnani ◽  
Puji Lestari
Keyword(s):  
Enzymatic Activity ◽  
Ammonium Sulphate ◽  
Crude Extract ◽  
Isolation Procedure ◽  
Optimum Temperature ◽  
Enzymes Activities ◽  
Optimum Ph ◽  
Ammonium Sulphate Fractionation

The ability of Peryonix excavatus to live in extremely dirty area indicates that P. excavatus secretes distinctive enzymes which might be useful for industry. Thus, this research were aimed to isolate amylase, lipase and protease from P. excavatus, and to characterize the enzymes to know the optimum temperature and pH. The isolation procedure consisted of extraction and ammonium sulphate fractionation. The results showed that crude extract and ammonium sulphate fractions of P.excavatus had amylase, lipase, and protease enzymes activities. Among the three enzymes, amylase had the highest enzymatic activity whereas lipase was the least. The optimum temperature of amylase, lipase and protease were 60, 40, and 60 oC, respectively. The optimum pH of amylase, lipase and protease were 7, 7, and 8, respectively.

scholarly journals Purification of soluble arylsulphatases from ox brain

1965 ◽  
Vol 97 (2) ◽  
pp. 360-364 ◽  
Author(s):  
W Bleszynski ◽  
LM Dzialoszynski
Keyword(s):  
Ammonium Sulphate ◽  
Specific Activity ◽  
Ammonium Sulphate Precipitation ◽  
Optimum Ph ◽  
Arylsulphatase A

1. Two soluble arylsulphatases (A and B) have been extracted from ox brain by a modified Albers autolysis method and purified by acetone and ammonium sulphate precipitation and dialysis. 2. A 1600-fold purification was achieved with arylsulphatase A and 320-fold purification with arylsulphatase B. 3. The specific activity of arylsulphatase A was 266000 4-nitrocatechol units/mg. of protein N, and that of arylsulphatase B was 64600units/mg. of protein N. 4. Arylsulphatase A seems to be electrophoretically homogeneous. 5. With 3mm-dipotassium 2-hydroxy-5-nitrophenyl sulphate as substrate the optimum pH for the activity of arylsulphatase A was 4.7, and for arylsulphatase B it was 6.1 with a 60mm solution of the same substrate.

scholarly journals Purification of NADP-Isocitrate dehydrogenase from Red Kidney beans (Phaseolus vulgaris rogue)

2010 ◽  
Vol 4 (1) ◽  
pp. 61-72
Author(s):  
Mukaram Shikara ◽  
Hiba Muneer Al-Khafagi ◽  
Wasnaa H. Faris
Keyword(s):  
Phaseolus Vulgaris ◽  
Isocitrate Dehydrogenase ◽  
Deae Cellulose ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Optimum Temperature ◽  
Ammonium Sulphate Precipitation ◽  
Kidney Beans ◽  
Optimum Ph ◽  
Murashige Skoog ◽  
Red Kidney Beans

Nicotinamide adenine dinucleotide phosphate-dependent isocitrate dehydrogenase (NADP+-IDH; EC 1.1.1.42) was extracted from red kidney beans (Phaseolus vulgaris.) after the beans were placed into Murashige-Skoog medium and incubated under continuous white light (110 μmol photon m−2 s−1), then filtered, centrifuged and the supernatant was used for purification. The enzyme purified using ammonium sulphate precipitation, DEAE-cellulose and Matrex Bio red A (dye-ligand-chromatography) techniques, and exhibits several bands through electrophoresis, with one band corresponds to the IDH activity. Km values for the enzyme was 55.71± 4.56 x 10-6M. The enzyme has an optimum pH at 8.5, and optimum temperature at 30°C. The enzyme can be stable at RT (about 25°C) for 180min, but the activity disappears at 400min. Enzyme activity appears to be independent of divalent metals in deionized water, but the addition of Mg+2 and Mn+2 by 4.5 and 2-folds respectively. The purified enzyme was injected into white rabbits to raise an antiserum against NADP+-IDH. The specificity of the antiserum was assayed by its ability to decrease the NADP+-IDH activity present in the extract. NADP+-IDH activity decreased when the extract was incubated with increasing volumes of the antiserum obtained.

scholarly journals Encapsulation of HRP Enzyme onto a Magnetic Fe3O4 Np–PMMA Film via Casting with Sustainable Biocatalytic Activity

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 181 ◽  
Author(s):  
Wesam H. Abdulaal ◽  
Yaaser Q. Almulaiky ◽  
Reda M. El-Shishtawy
Keyword(s):  
Metal Ions ◽  
Immobilized Enzyme ◽  
Pmma Film ◽  
Optimum Temperature ◽  
Initial Activity ◽  
Casting Method ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Triton X ◽  
Enzyme Changes

Horseradish peroxidase (HRP) enzyme was effectively encapsulated onto an Fe3O4 nanoparticle–polymethyl methacrylate (PMMA) film via the casting method. The HRP was immobilized on the 0.5% Fe3O4Np–PMMA film and characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Moreover, the reusability, thermal stability, optimum pH, optimum temperature, the influence of metal ions, and the effects of detergent and organic solvent were investigated. After optimizing the immobilization conditions, the highest efficiency of the immobilized enzyme was 88.4% using 0.5% Fe3O4Np–PMMA. The reusability of the immobilized HRP activity was 78.5% of its initial activity after being repeatedly used for 10 cycles. When comparing the free and immobilized forms of the HRP enzyme, changes in the optimum temperature and optimum pH from 30 to 40 °C and 7.0 to 7.5, respectively, were observed. The Km and Vmax for the immobilized HRP were estimated to be 41 mM, 0.89 U/mL for guaiacol and 5.84 mM, 0.66 U/mL for H2O2, respectively. The high stability of the immobilized HRP enzyme was obtained using metal ions, a high urea concentration, isopropanol, and Triton X-100. In conclusion, the applicability of immobilized HRP involves the removal of phenol in the presence of hydrogen peroxide, therefore, it could be a potential catalyst for the removal of wastewater aromatic pollutants.

THE INFLUENCE OF ETHANOL ON THE CONVERSION OF PREGNENOLONE TO PROGESTERONE BY HUMAN PLACENTAL MICROSOMES

1974 ◽  
Vol 76 (1) ◽  
pp. 178-188 ◽  
Author(s):  
H. Lübbert ◽  
K. Pollow ◽  
R. Wagner ◽  
J. Hammerstein
Keyword(s):  
Kinetic Parameters ◽  
Enzyme Preparation ◽  
Ethanol Concentration ◽  
Hydroxysteroid Dehydrogenase ◽  
Product Formation ◽  
Linear Increase ◽  
Maximal Velocity ◽  
Microsomal Enzyme ◽  
Temperature Optima ◽  
Substrate Concentrations

ABSTRACT The effects of ethanol on kinetic parameters of placental Δ5-3β-hydroxysteroid dehydrogenase were studied. In the presence of high pregnenolone concentrations (50 μm, [S] > Km) the microsomal enzyme preparation exhibited an almost linear increase in activity as the ethanol concentration in the medium was raised from 2.5 to 15 % (v/v). At lower substrate concentrations ([S] << Km) ethanol caused inhibition. Other effects of ethanol were: linearity of product formation with time was prolonged; the maximal velocity was markedly increased; the Km for pregnenolone slightly decreased with increasing ethanol concentrations (2.5 to 10 %, v/v) whereas the Km for NAD remained the same. The pH and temperature optima of the reaction were unaffected by ethanol. Other organic solvents caused similar effects.

scholarly journals Thermostable glucose isomerase from psychrotolerant Streptomyces species

1970 ◽  
Vol 1 ◽  
pp. 6-10 ◽  
Author(s):  
Bidur Dhungel ◽  
Manoj Subedi ◽  
Kiran Babu Tiwari ◽  
Upendra Thapa Shrestha ◽  
Subarna Pokhrel ◽  
...  
Keyword(s):  
Specific Activity ◽  
Fold Increase ◽  
Glucose Isomerase ◽  
Enzyme Concentration ◽  
Maximal Velocity ◽  
Ph Optimum ◽  
Streptomyces Spp ◽  
Optimum Ph ◽  
Optimum Reaction ◽  
Sepharose 4B

Glucose isomerase (EC 5.3.1.5) was extracted from Streptomyces spp., isolated from Mt. Everest soil sample, and purified by ammonium sulfate fractionation and Sepharose-4B chromatography. A 7.1 fold increase in specific activity of the purified enzyme over crude was observed. Using glucose as substrate, the Michaelis constant (KM<) and maximal velocity (Vmax) were found to be 0.45M and 0.18U/mg. respectively. The optimum substrate (glucose) concentration, optimum enzyme concentration, optimum pH, optimum temperature, and optimum reaction time were 0.6M, 62.14μg/100μl, 6.9, 70ºC, and 30 minutes, respectively. Optimum concentrations of Mg2+ and Co2+ were 5mM and 0.5mM, respectively. The enzyme was thermostable with half-life 30 minutes at 100ºC.DOI: 10.3126/ijls.v1i0.2300 Int J Life Sci 1 : 6-10

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