scholarly journals Purification and characterization of N-acetylglutamate 5-phosphotransferase from pea (Pisum sativum) cotyledons

1981 ◽  
Vol 195 (1) ◽  
pp. 71-81 ◽  
Author(s):  
G McKay ◽  
P D Shargool
Keyword(s):  
Pisum Sativum ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Kinetic Studies ◽  
Exchange Chromatography ◽  
Purification And Characterization ◽  
Coomassie Blue ◽  
Km Value ◽  
Acetylglutamate Kinase

N-Acetylglutamate 5-phosphotransferase (acetylglutamate kinase, EC 2.7.2.8) has been isolated from pea (Pisum sativum) cotyledons and purified 312-fold by using heat treatment, (NH4)2SO4 fractionation, affinity chromatography on ATP--Sepharose and ion-exchange chromatography on DEAE-cellulose. This preparation was shown on polyacrylamide-gel electrophoresis to yield one band staining with Coomassie Blue. The enzyme was shown by a variety of techniques to be composed of two different kinds of subunits, of mol.wts. 43000 and 53000 respectively. These subunits are arranged to give either a dimeric or tetrameric enzyme composed of equal numbers of each type of subunit. The dimeric and tetrameric enzyme forms are thought to be interconvertible, the equilibrium between these forms being influenced by the type of ligand bound to the subunits. Kinetic studies performed on the purified enzyme, indicated a random Bi Bi type of mechanism. The enzyme displayed apparent negative co-operativity with respect to one of its substrates, N-acetylglutamate; as a result, two Km values were found for this substrate, one at 1.9 X 10(-3) M and the other at 6.2 X 10(-3) M. A single Km value for ATP was found to be 1.7 X 10(-3) M. Allosteric regulation by arginine was also shown. A model, based on the Koshland, Némethy & Filmer [(1966) Biochemistry 5, 365-385] Sequential model, which adequately describes the kinetic and structural properties of N-acetylglutamate 5-phosphotransferase, is presented.

scholarly journals Purification and characterization of acid phosphatase from a germinating black gram (Vigna mungo L.) seedling

2011 ◽  
Vol 63 (3) ◽  
pp. 747-756 ◽  
Author(s):  
A.K.M. Asaduzzaman ◽  
Habibur Rahman ◽  
Tanzima Yeasmin
Keyword(s):  
Acid Phosphatase ◽  
Gel Electrophoresis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Inhibitory Effect ◽  
Maximum Activity ◽  
Exchange Chromatography ◽  
Black Gram ◽  
Km Value

An acid phosphatase has been isolated and purified from an extract of a germinating black gram seedling. The method was accomplished by gel filtration of a germinating black gram seedling crude extract on sephadex G-75 followed by ion exchange chromatography on DEAE cellulose. The acid phosphatase gave a single band on SDS-polyacrylamide slab gel electrophoresis. The molecular weight of the acid phosphatase determined by SDS-polyacrylamide slab gel electrophoresis was estimated to be 25 kDa. The purified enzyme showed maximum activity at pH 5 and at temperature of 55?C. Mg2+, Zn2+ and EDTA had an inhibitory effect on the activity of the acid phosphatase. Black gram seedling acid phosphatase was activated by K+, Cu2+ and Ba2+. The Km value of the enzyme was found to be 0.49 mM for pNPP as substrate.

scholarly journals The purification and characterization of glucokinase from the thermophile Bacillus stearothermophilus

1986 ◽  
Vol 237 (2) ◽  
pp. 415-420 ◽  
Author(s):  
C R Goward ◽  
R Hartwell ◽  
T Atkinson ◽  
M D Scawen
Keyword(s):  
Large Scale ◽  
Bacillus Stearothermophilus ◽  
Specific Activity ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Purification And Characterization ◽  
Km Value ◽  
Extraneous Material ◽  
Sepharose 4B

Homogeneous glucokinase (EC 2.7.1.2) from the thermophile Bacillus stearothermophilus was isolated on the large scale by using four major steps: precipitation of extraneous material at pH 5.5, ion-exchange chromatography on DEAE-Sepharose, pseudo-affinity chromatography on Procion Brown H-3R-Sepharose 4B and gel filtration on Ultrogel AcA 34. The purified enzyme had a specific activity of about 330 units/mg of protein and was shown to exist as a dimer of subunit Mr 33,000. Kinetic parameters for the enzyme were determined with a variety of substrates. The glucokinase was highly specific for alpha-D-glucose, and the only other sugar substrate utilized was N-acetyl-alpha-D-glucosamine. The enzyme shows Michaelis-Menten kinetics, with a Km value of 150 microM for alpha-D-glucose. The glucokinase was maximally active at pH 9.0.

scholarly journals Partial Purification and Characterization of Catalase from Banana Peels

2016 ◽  
Vol 13 (2) ◽  
pp. 392-398
Author(s):  
Baghdad Science Journal
Keyword(s):  
Gel Filtration ◽  
Maximum Velocity ◽  
Kinetic Studies ◽  
Maximal Activity ◽  
Partial Purification ◽  
Purification And Characterization ◽  
Km Value ◽  
Almost All ◽  
Kinetics Of

Catalase (EC 1.11.1.6) is a well known enzyme which exists in almost all living creatures exposing to oxygen (such as plants, bacteria, and animals). It is a very necessary enzyme to protect the cell from oxidative detriment by reactive oxygen species (ROS). The aim of this study is the partial purification and characterization of Catalase enzyme from Banana peels. In this study, fresh banana peels are treated with 70 % ethanol ,further separated with chloroform ,water and ethyl acetate respectively .The supernatant of the enzymatic sample which is treated with chloroform is loaded into gel filtration column with Sephadex G-100 (1.0 x 90 cm) equilibrated with pH7 buffer media (phosphate buffer 0.1 M). Kinetic studies of the purified enzyme activity are measured and characterized .The maximal activity (26.04 units/mg) of catalase is observed with chloroform buffer extraction. The kinetics of catalase; Michalis constant Km and maximum velocity Vmax is determined using Linweaver- Burk plot, The Km value for catalase (434.7mM), Vmax (100 m mole min -1). Characterization results demonstrate that the optimal pH for activity is (7.6). And the optimal temperature for activity is 30?C .The present study indicates that Banana peels is a good source of catalase enzyme.

Purification and Characterization of Ginsenoside-Hydrolyzing β-Glucosidase from Wheat Bran

2013 ◽  
Vol 641-642 ◽  
pp. 906-909
Author(s):  
Chun Zhi Zhang ◽  
Ming Chen ◽  
Hai Chen Guo ◽  
Guo Ren Zu ◽  
Li Chen
Keyword(s):  
Molecular Weight ◽  
Wheat Bran ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Polyacrylamide Gel ◽  
Purification And Characterization ◽  
Enzyme Solution ◽  
Crude Enzyme Solution

The ginsenoside-hydrolyzing β-glucosidase that can converse the major ginsenosides into the minor ginsenosides was isolated from wheat bran, and the enzyme was purified and characterized. The crude enzyme solution extracted from wheat bran could hydrolyse the protopanaxadiol-type ginsenosides such as Rb1, Rc, Rd and Rg3, but could not hydrolyse the protopanaxatriol-type ginsenosides such as Re and Rg2. The enzyme fractionated on the DEAE-Cellulose DE-52 column was purified to one spot in SDS polyacrylamide gel electrophoresis, and the molecular weight of enzyme in the fraction 34, 47, and 61 was approximately 62 kDa, 62 kDa, and 68 kDa, respectively.

scholarly journals Identification of a Marine AgarolyticPseudoalteromonas Isolate and Characterization of Its Extracellular Agarase

1998 ◽  
Vol 64 (11) ◽  
pp. 4378-4383 ◽  
Author(s):  
Jorge Vera ◽  
Raul Alvarez ◽  
Erminio Murano ◽  
Juan Carlos Slebe ◽  
Oscar Leon
Keyword(s):  
Pacific Coast ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Maximal Activity ◽  
Exchange Chromatography ◽  
Phenotypic Characters ◽  
Solid Agar

ABSTRACT The phenotypic and agarolytic features of an unidentified marine bacteria that was isolated from the southern Pacific coast was investigated. The strain was gram negative, obligately aerobic, and polarly flagellated. On the basis of several phenotypic characters and a phylogenetic analysis of the genes coding for the 16S rRNA, this strain was identified as Pseudoalteromonas antarcticastrain N-1. In solid agar, this isolate produced a diffusible agarase that caused agar softening around the colonies. An extracellular agarase was purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography on DEAE-cellulose. The purified protein was determined to be homogeneous on the basis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and it had a molecular mass of 33 kDa. The enzyme hydrolyzed the β-1,4-glycosydic linkages of agar, yielding neoagarotetraose and neoagarohexaose as the main products, and exhibited maximal activity at pH 7. The enzyme was stable at temperatures up to 30°C, and its activity was not affected by salt concentrations up to 0.5 M NaCl.

scholarly journals Purification and characterization of a heterogeneous glycosylated invertase from the rumen holotrich ciliate Isotricha prostoma

1989 ◽  
Vol 264 (3) ◽  
pp. 721-727 ◽  
Author(s):  
T Dauvrin ◽  
D Thinès-Sempoux
Keyword(s):  
Enzyme Purification ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Product Inhibition ◽  
Maximum Activity ◽  
Kinetic Properties ◽  
Transferase Activity ◽  
Purification And Characterization ◽  
Sepharose 4B

The invertase (beta-fructofuranosidase, EC 3.2.1.26) of the rumen holotrich ciliate Isotricha prostoma has been purified. This is the first report of an enzyme purification from a known species of rumen protozoon. Cells were disrupted by ultrasonic treatment and the enzyme was purified from the cell-free extract by three successive liquid column chromatographies (Sepharose CL4B/octyl-Sepharose CL4B, DE52 DEAE-cellulose and concanavalin A-Sepharose 4B). This resulted in a 160-fold purification and a 15% yield. The major form of the purified enzyme was a tetramer with Mr about 350,000 that was readily dissociated by electrophoresis. The invertase was heterogeneous, as five types of monomers were shown by SDS/polyacrylamide-gel electrophoresis after denaturation. Part of this heterogeneity was due to different glycosylated forms of one of the polypeptides present in the purified enzyme. Isotricha prostoma invertase exhibited maximum activity at pH 5.5-6.0 and 50 degrees C. The kinetic properties of the purified enzyme were very similar to those of invertases from other sources such as yeast or plants (substrate and product inhibition, transferase activity).

Purification and Characterization of an α-Glucosidase from Rhizobium sp. (Robinia pseudoacacia L.) Strain USDA 4280

1999 ◽  
Vol 65 (7) ◽  
pp. 2907-2911 ◽  
Author(s):  
Karine Berthelot ◽  
Francis M. Delmotte
Keyword(s):  
Enzyme Activity ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Robinia Pseudoacacia ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Purification And Characterization ◽  
Robinia Pseudoacacia L ◽  
Strain Usda

ABSTRACT A novel α-glucosidase with an apparent subunit mass of 59 ± 0.5 kDa was purified from protein extracts of Rhizobium sp. strain USDA 4280, a nodulating strain of black locust (Robinia pseudoacacia L), and characterized. After purification to homogeneity (475-fold; yield, 18%) by ammonium sulfate precipitation, cation-exchange chromatography, hydrophobic chromatography, dye chromatography, and gel filtration, this enzyme had a pI of 4.75 ± 0.05. The enzyme activity was optimal at pH 6.0 to 6.5 and 35°C. The activity increased in the presence of NH4 +and K+ ions but was inhibited by Cu2+, Ag+, Hg+, and Fe2+ ions and by various phenyl, phenol, and flavonoid derivatives. Native enzyme activity was revealed by native gel electrophoresis and isoelectrofocusing-polyacrylamide gel electrophoresis with fluorescence detection in which 4-methylumbelliferyl α-glucoside was the fluorogenic substrate. The enzyme was more active with α-glucosides substituted with aromatic aglycones than with oligosaccharides. This α-glucosidase exhibited Michaelis-Menten kinetics with 4-methylumbelliferyl α-d-glucopyranoside (Km , 0.141 μM; V max, 6.79 μmol min−1 mg−1) and withp-nitrophenyl α-d-glucopyranoside (Km , 0.037 μM; V max, 2.92 μmol min−1 mg−1). Maltose, trehalose, and sucrose were also hydrolyzed by this enzyme.

scholarly journals Purification and Characterization of ?-N-Acetylgalactosaminidase from Hilsha ilisha

2017 ◽  
Vol 9 (2) ◽  
pp. 235-246
Author(s):  
M. H. Rashid ◽  
A. H. M. K. Alam ◽  
J. Uddin ◽  
N. Karim ◽  
M. G. Sadik
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Kinetic Studies ◽  
Ammonium Sulphate Precipitation ◽  
Heat Stable ◽  
Optimum Ph ◽  
Km Value ◽  
C 50 ◽  
Inhibition Studies

The objective of this study was to purify and characterize the alpha-N-acetylgalactosaminidase (?-GalNAcase) from hilsha fish, Hilsha ilisha. Digestive organ of hilsha fish was found to contain a large amount of ?-GalNAcase in compared with the other tissues examined. ?-GalNAcase was purified from the crude extract of hilsha fish by ammonium sulphate precipitation, Sephadex G-200 gel filtration, and SP-Sephadex C-50 column chromatography. The purified enzyme gave a single band on sodium dodecylsulphate-polyacrylamide gel electrophoresis and exhibited a molecular mass of 48 kDa. The final preparation of ?-GalNAcase showed 3.02% ?-galactosidase activity. The enzyme had an optimum pH of 4.0 and was found to be quiet heat stable at 37°C. Inhibition studies with metal ions demonstrated that the enzyme was highly inhibited by silver and mercury ions. Both N-acetylgalactosamine and galactose affect the enzyme activity. Kinetic studies with the enzyme showed that the KM value for p-nitrophenyl-?-N-acetylgalactosaminide substrate was 3.31 mM and the Vmax value was 35.04 unit/mg.

Purification and characterization of cholesterol sulfotransferase from rat skin

2001 ◽  
Vol 79 (4) ◽  
pp. 499-506 ◽  
Author(s):  
James I Rearick ◽  
Eric S Calhoun
Keyword(s):  
Gel Electrophoresis ◽  
Molecular Mechanisms ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Partial Purification ◽  
Epidermal Keratinocytes ◽  
Rat Skin ◽  
Purification And Characterization ◽  
Coomassie Blue

Previous work has demonstrated that the activity of the enzyme cholesterol sulfotransferase is rapidly and dramatically increased upon squamous differentiation of a variety of epithelial cells in culture, including epidermal keratinocytes. As a step toward understanding the molecular mechanisms underlying this differentiation-related change, we now report the partial purification and characterization of this enzyme activity from rat skin. Supernatant solutions from rat skin homogenates were subjected to a series of column chromatography steps including anion exchange, gel filtration, chromatofocusing and hydrophobic interaction chromatography. The purification procedure resulted in cholesterol sulfotransferase activity purified 2700-fold with a 11% recovery. The most purified preparation yielded a major Coomassie blue-stained band on denaturing polyacrylamide gel electrophoresis of an apparent molecular weight (MW) of 40 000 Da. Photoaffinity labeling with the donor substrate, 3'-phosphoadenosine-5'-phospho-[35S]-sulfate resulted in a single radiolabeled protein band on denaturing polyacrylamide gel electrophoresis, again of apparent MW 40 000 Da, strongly suggesting that the major Coomassie blue-stained band in the most purified preparation is the cholesterol sulfotransferase protein. Among 3β-hydroxysteroids with a Δ5 double bond that were tested, each served as a substrate, while androgens, estrogens, corticosteroids, p-nitrophenol and DOPA did not serve as substrates. Apparent Michaelis constants for the 3β-hydroxysteroid substrates ranged from 0.6 to 8 µM.Key words: sulfotransferase, ichthyosis, cholesterol, skin, enzymology.

Prothrombin Metz : Purification and Characterization of a Variant of Human Prothrombin

1979 ◽  
Author(s):  
M Ribieto ◽  
J Elion ◽  
D Labie ◽  
F Josso
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Cleavage Pattern ◽  
Purification And Characterization ◽  
Double Immunodiffusion ◽  
The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.

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