scholarly journals Isolation and characterization of 17β-hydroxy steroid dehydrogenase from human erythrocytes

1972 ◽  
Vol 127 (4) ◽  
pp. 649-659 ◽  
Author(s):  
E. Mulder ◽  
G. J. M. Lamers-Stahlhofen ◽  
H. J. Van Der Molen

1. The 17β-hydroxy steroid dehydrogenase was solubilized during haemolysis of erythrocytes and was isolated from the membrane-free haemolysate. Membrane preparations isolated in different ways did not contain 17β-hydroxy steroid dehydrogenase activity. The 17β-hydroxy steroid dehydrogenase activity in the haemolysate was concentrated by repeated ammonium sulphate precipitation and gel filtration on Sephadex G-150. The 17β-hydroxy steroid dehydrogenase activity of the purified preparation per unit weight of protein was 350–3000 times higher than the activity of the crude erythrocyte haemolysate. The 20α-hydroxy steroid dehydrogenase activity was lost during this purification procedure. 2. The 17β-hydroxy steroid dehydrogenase was NADP-dependent and had a pH optimum for conversion of testosterone between 8.5 and 10. For the molecular weight of the enzyme a value of 64000 was calculated from Sephadex chromatography results. 3. p-Chloromercuribenzoate inhibited the enzymic activity. The oxidative activity of the enzyme for the 17β-hydroxyl group was only partly inhibited when a large excess of 17-oxo steroids was added. The catalysing activity of the enzyme was influenced by the NADP+/NADPH ratio. The oxidation of the 17β-hydroxyl group in the presence of NADP+ proceeded faster than the reduction of the 17-oxo group with NADPH. When both reduced and oxidized cofactors were present the oxidation of the 17β-hydroxyl group was inhibited to a considerable extent. 4. The enzyme had a broad substrate specificity and not only catalysed the conversion of androstanes with a 17β-hydroxyl group, or 17-oxo group, but also the conversion oestradiol⇆oestrone. In addition the steroid conjugates dehydroepiandrosterone sulphate and oestrone sulphate were also converted. There were no indications that more than one 17β-hydroxy steroid dehydrogenase was present in the partially purified preparation.

1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.


1993 ◽  
Vol 71 (1-2) ◽  
pp. 22-26 ◽  
Author(s):  
Pratima Dutta ◽  
Gopal C. Majumder

A neutral β-D-galactosidase has been partially purified from rat epididymis and characterized. The enzyme having molecular mass of approximately 50 kilodaltons has been purified 400-fold by using calcium phosphate gel adsorption, DEAE-cellulose chromatography, Sephadex G-100 gel filtration, and concanavalin A - agarose affinity chromatography. Although the neutral enzyme binds to the concanavalin A affinity column, the activity could be eluted with α-methyl mannoside only if the buffer contained salt (NaCl) at a concentration as high as 0.3 M. The enzyme was of cytosolic origin, since 90% of the total enzymic activity of the tissue homogenate was recovered in the soluble fraction of these cells. The neutral β-galactosidase was not dependent on metal ions for its activity and it had a pH optimum of 7.0. Zn2+, p-chloromercuribenzoate, Hg2+, and Pb2+ served as potent inhibitors of the enzyme. There was a marked increase (approximately fourfold) in the specific activity of the neutral β-galactosidase during sexual maturity of epididymis in vivo.Key words: neutral β-galactosidase, rat epididymal, cytosolic, developmental, sexual maturity.


1976 ◽  
Vol 157 (1) ◽  
pp. 207-210 ◽  
Author(s):  
E S Haslewood ◽  
G A D Haslewood

1. Thirty-eight steroids were tested as substrates for a 7 alpha-hydroxy steroid dehydrogenase preparation from a strain of Escherichia coli; an improved method of making the crude enzyme is described. 2. Steroids having a 7 alpha-hydroxyl group in the molecule were substrates except (a) when the 5 beta-cholan-24-oic acid side chain was shortened to less than four carbon atoms and (b) in certain cases when sulphate ester groups were present in the molecule. 3. For testing with the enzyme, a new specimen of 7 alpha-hydroxy-3,12-dioxo-5 beta-cholan-24-oic acid was made, which had properties different from those previously described.


1979 ◽  
Vol 181 (3) ◽  
pp. 685-689 ◽  
Author(s):  
D G Armstrong

1. The distribution of 3 beta-hydroxy steroid dehydrogenase was examined in the subcellular fractions of granulosa cells collected from the ovary of the domestic fowl. 2. 3 beta-hydroxy steroid dehydrogenase activity was observed in the mitochondrial (4000g for 20min) and microsomal (105 000g for 120min) fractions. 3. Approximately three times more 3 beta-hydroxy steroid dehydrogenase activity was associated with the cytochrome oxidase activity (a mitochondrial marker enzyme) in anteovulatory-follicle granulosa cells than with that of the postovulatory follicle. 4. Comparison of the latent properties of mitochondrial 3 beta-hydroxy steroid dehydrogenase with those of cytochrome oxidase and isocitrate dehydrogenase indicated that 3 beta-hydroxy steroid dehydrogenase is located extramitochondrially. 5. This apparent distribution of 3 beta-hydroxy steroid dehydrogenase is explained on the basis that the mitochondrial activity is either an artefact caused by a redistribution in the subcellular location of the enzyme, occurring during homogenization, or by the existence of a functionally heterogeneous endoplasmic reticulum that yields particles of widely differing sedimentation properties.


1979 ◽  
Vol 34 (9-10) ◽  
pp. 726-737 ◽  
Author(s):  
Kunhard Pollow ◽  
Walter Eiger ◽  
Herrmann Heßlinger ◽  
Barbara Pollow

Abstract 17 β-Hydroxysteroid dehydrogenase activity towards estradiol-17 β has been demonstrated in the 105,000 X g supernatant of rabbit uterus. Hydroxylapatite chromatography of the enzyme activity isolated by ammonium sulfate precipitation, gel filtration and DEAE-cellulose chromato­graphy yielded a single 17 β-hydroxysteroid dehydrogenase activity. Further purification of the enzyme preparation by isoelectric focusing resulted in multiple peaks of activity. The molecular weight or the enzyme, calculated from mobility data on Sephadex gel, is approximately 64,000. Some properties of partially purified 17 β-hydroxysteroid dehydrogenase activity have been studied. Estradiol-17 β reacts at a faster rate than testosterone. The Km for estradiol is 4.16X 10-5 mol/1 for the NAD-linked enzyme activity and 4.37 X 10-5 mol/1 when NADP as cofactor was used. The ratio of the maximal velocity for NADP to that for NAD was 1.42. The pH-optimum for estradiol appears between 9.5 and 10.5 and for estrone between 5.5 and 6.5. The enzyme appears to be of the sulfhydryl type.


2001 ◽  
Vol 44 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Sailas Benjamin ◽  
Ashok Pandey

Three distinct forms (Lip A, Lip B and Lip C) of extra-cellular lipases (EC- 3.1.1.3), produced by Candida rugosa in solid state fermentation (SSF) were purified and characterised. SSF was carried out in glass columns using coconut oil cake and wheat bran. The enzyme was purified from the aqueous extract of fermented matter by ammonium sulphate precipitation, dialysis, ultra-filtration and gel filtration using Sephadex-200 to a 43-fold purification and 64.35-mg/ml specific activity. SDS-PAGE of purified enzyme revealed three distinct bands, indicating the existence of three iso-forms, Lip A, Lip B and Lip C with apparent molecular weight about 64,000, 62,000 and 60,000 Da, respectively. All the three iso-forms were optimally active at 35-40°C and pH 7-8. They showed marked differences in their Km values with different saturated and unsaturated triacyl glycerols. Ag++ and Hg++ strongly inhibited enzyme activity of all the iso-forms, Mn++ has no effect and Ca++ and Mg++ enhanced the activity. EDTA also strongly inhibited the enzyme activities of iso-forms. However, activities of all the three lipases were completely inhibited by serine protease inhibitors such as 3,4-dichloroisocoumarin, pefabloc and partially by phenylmethanesulphonyl fluoride. To the best of our knowledge, this is the first report describing the purification and characterisation of C. rugosa lipase iso-forms from solid cultures. These lipase iso-forms with diverse characteristics produced in solid cultures may find potential application in biomedical field.


1996 ◽  
Vol 316 (3) ◽  
pp. 723-727 ◽  
Author(s):  
Q. Khai HUYNH ◽  
Jeffry R. BORGMEYER ◽  
Christine E. SMITH ◽  
Leslie D. BELL ◽  
Dilip M. SHAH

During the course of screening plants for novel antifungal activity, we found that a high-molecular-mass fraction of an extract from leaves of Engelmannia pinnatifida exhibited potent and broad-spectrum antifungal activity. In this study a 30 kDa protein from E. pinnatifida leaves was purified to homogeneity by ammonium sulphate precipitation, gel filtration, Mono-Q and C18 reverse-phase column chromatographies. The purified protein showed potent antifungal activity against various plant pathogens with as little as 50 ng. The N-terminal amino acid sequence of the purified protein was determined as XXTKFDFFTLALQXPAXF, where X indicates an unidentified residue. This sequence showed 35–50% sequence identity with purified style glycoproteins associated with self-incompatibility from wild tomato, tobacco and petunia, a phosphate-starvation-induced ribonuclease from cultured tomato cells and the SIR 63.4 kDa protein from yeast.


Author(s):  
Chimdi E. Esonu ◽  
G. O. C. Onyeze ◽  
Kizito M. E. Iheanacho ◽  
Linus N. Nwaogu ◽  
Simon-Peter Odirichukwu

Aim: This study focused on the extraction, purification and kinetic studies of lactate dehydrogenase of male chickens from Ebocha oil exploration area, Imo state, Nigeria. Methods: Twenty-one apparently healthy mature (6-9 months) male chickens (Gallus domesticus) from Ebocha oil exploration area, Imo State, Nigeria were screened for lactate dehydrogenase activity, thus accessing the level of chronic cell exposure to gas flaring. Their thigh muscle tissues were severed and investigated for lactate dehydrogenase activity using the standard method and sodium pyruvate as the substrate. Lactate dehydrogenase was isolated and purified by ammonium sulphate precipitation, desalted by dialysis and then gel filtration. Results: The enzyme activity increased with advancement in the purification steps and was maximum using dialysis. The values for the lactate dehydrogenase activities were 103.43±3.27 U/L, 279.50±5.38 U/L, 318.16±13.08 U/L, 100.47±2.59 U/L, with a purification fold of 1, 3.7, 6.24 and 2.55 for the purification steps respectively. Also, the values of the protein concentrations were 0.071 mg/ml, 0.050 mg/ml, 0.035 mg/ml and 0.027 mg/ml (values for the crude enzyme, ammonium sulphate precipitation, dialysis and gel filtration respectively). The enzyme showed optimal activity at pH range of 5.5-6.5 and temperature of 30ºC-40ºC. Using sodium pyruvate as the substrate, with a fixed enzyme volume, an increase in the concentration of substrate resulted in increase in enzyme activity until a saturation point 0.3mM was reached. The apparent Km and Vmax values obtained were 0.01 mM and 0.12 U/mg/min. The Lineweaver-burk plot of the partially purified enzyme gave real Km and Vmax values of 0.20 mM and 0.16 U/mg/min respectively. Conclusion: Partial purification procedures and biochemical properties of lactate dehydrogenase, from the muscle tissues of male chickens of Ebocha origin, gives room for more investigation on the metabolic shift caused by chronic exposure of the environment, humans and livestock to gas flaring and petroleum exploration.


1965 ◽  
Vol 48 (3) ◽  
pp. 429-438 ◽  
Author(s):  
A. H. Baillie ◽  
M. Niemi ◽  
M. Ikonen

ABSTRACT Sections of testes from nine human foetuses ranging in crown-rump length from 3.0 to 18.3 cm were incubated to determine 3β-hydroxy-steroid dehydrogenase activity histochemically with the following steroids: 3β-hydroxy-pregn-5-en-20-one (pregnenolong). 3β,17α-dihydroxy-pregn-5-en-20-one (17α-hydroxypregnenolone). 3β-hydroxy-androst-5-en-17-one (DHA). 3β,17β-dihydroxy-androst-5-ene (androstenediol). 3β-sulphoxy-pregn-5-en-20-one (pregnenolone sulphate). 3β-sulphoxy-1 7α-hydroxy-pregn-5-en-20-one (17α-hydroxy-pregnenolone sulphate) 3β-sulphoxy-androst-5-en-17-one (DHAsulphate). 3β-hydroxy-5α-androstan-17-one (epiandrosterone). Pregnenolone and DHA gave a colour reaction in the interstitium of all testes studied. 17α-hydroxypregnenolone was utilised by testes from foetuses of C-R length 8.8 cm and over, androstenediol by testes from foetuses of C-R length 6.1 cm and over. These facts are thought to support the concept of separate substrate-specific 3β-hydroxysteroid dehydrogenases in the testis. Pregnenolone sulphate was used by the interstitial cells of all testes studied but gave a stronger reaction than the free steroid. 17α-hydroxy-pregnenolone sulphate was used by all foetal testes surveyed. DHA sulphate was not well used by the interstitial cells. The utilisation of steroid sulphates in a different manner from the free steroids in this histochemical system may mean that the presence of a sulphate group affects enzyme-substrate binding or that a steroid sulphatase is involved. Intense formazan deposition followed incubation with epiandrosterone in all testes studied. This seems to imply that a δ5 configuration is not necessary for enzyme-substrate binding.


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