scholarly journals Heterologous expression, purification and characterization of rat class theta glutathione transferase T2-2

1996 ◽  
Vol 316 (1) ◽  
pp. 131-136 ◽  
Author(s):  
Per JEMTH ◽  
Gun STENBERG ◽  
Grigoriy CHAGA ◽  
Bengt MANNERVIK
Keyword(s):  
Glutathione Transferase ◽  
Specific Activity ◽  
Catalytic Efficiency ◽  
Exchange Chromatography ◽  
Rat Tissues ◽  
Low Concentrations ◽  
Km Value ◽  
Micromolar Range ◽  
Uncatalysed Reaction

Rat glutathione transferase (GST) T2-2 of class Theta (rGST T2-2), previously known as GST 12-12 and GST Yrs-Yrs, has been heterologously expressed in Escherichia coli XL1-Blue. The corresponding cDNA was isolated from a rat hepatoma cDNA library, ligated into and expressed from the plasmid pKK-D. The sequence is the same as that of the previously reported cDNA of GST Yrs-Yrs. The enzyme was purified using ion-exchange chromatography followed by affinity chromatography with immobilized ferric ions, and the yield was approx. 200 mg from a 1 litre bacterial culture. The availability of a stable recombinant rGST T2-2 has paved the way for a more accurate characterization of the enzyme. The functional properties of the recombinant rGST T2-2 differ significantly from those reported earlier for the enzyme isolated from rat tissues. These differences probably reflect the difficulties in obtaining fully active enzyme from sources where it occurs in relatively low concentrations, which has been the case in previous studies. 1-Chloro-2,4-dinitrobenzene, a substrate often used with GSTs of classes Alpha, Mu and Pi, is a substrate also for rGST T2-2, but the specific activity is relatively low. The Km value for glutathione was determined with four different electrophiles and was found to be in the range 0.3 mM–0.8 mM. The Km values for some electrophilic substrates were found to be in the micromolar range, which is low compared with those determined for GSTs of other classes. The highest catalytic efficiency was obtained with menaphthyl sulphate, which gave a kcat/Km value of 2.3×106 s-1·M-1 and a rate enhancement over the uncatalysed reaction of 3×1010.

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 Kinetic Characterization of β-xylosidase (GbtXyl43A) from Wild-type Geobacillus thermoleovorans IT-08 and The Variant GbtXyl43A-D121N

2020 ◽  
Author(s):  
Ika Fitriani Juli Palupi ◽  
Kartika Dwi Asni Putri ◽  
Ni Nyoman Purwani ◽  
Sri Sumarsih ◽  
Ni Nyoman Tri Puspaningsih
Keyword(s):  
Catalytic Mechanism ◽  
Specific Activity ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Kinetic Characteristics ◽  
Wild Type ◽  
Geobacillus Thermoleovorans ◽  
Purity Level ◽  
Km Value

GbtXyl43A, a β-xylosidase that is isolated from Geobacillus thermoleovorans IT-08 and grouped in GH43 family. The substitution of 121Asp residue with Asn in GbtXyl43A caused decrease the enzyme activity. The aim of this study, determine the kinetic characteristics of wild-type GbtXyl43A and D121N variant using Vmax, KM, kcat, and kcat/KM. These parameters indicated catalytic mechanism of GbtXyl43A and its derivative. All of them were produced in Escherichia coli BL21 star. The purification of wild-type GbtXyl43A using affinity chromatography, but D121N variant also required anion-exchange chromatography. The specific activity of wild-type GbtXyl43A and D121N variant were 0.471 U mg-1 in purity level 55,44 and 0.012 U mg-1 in purity level 2,407, respectively. Both enzymes had same molecular weight, ~58 kDa. The kinetic parameters of wild-type GbtXyl43A were KM: 2.845 mM, kcat: 0.033 s-1, Vmax: 0.0033 mM min-1and kcat/KM: 0.0115 s-1mM-1. Furthermore, the KM, kcat, Vmax, and kcat/KM values of D121N variant were 4.565 mM, 1.01 × 10-4 mM min-1, 0.140 × 10-4 s-1, and 0.0307 s-1mM-1, respectively. The KM value of the D121N variant was higher than its wild type and showed the affinity of D121N variant was lower than GbtXyl43A

Kinetic and Thermodynamic Characterization of Lignin Peroxidase Isolated from Agaricus bitorqus A66

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Ismat Bibi ◽  
Haq Nawaz Bhatti
Keyword(s):  
Lignin Peroxidase ◽  
Thermal Inactivation ◽  
Specific Activity ◽  
Gel Filtration ◽  
Veratryl Alcohol ◽  
Exchange Chromatography ◽  
Different Temperatures ◽  
Scale Experiment ◽  
Menten Kinetic

This study deals with purification and characterization of lignin peroxidase (LiP) isolated from Agaricus bitorqus A66 during decolorization of NOVASOL Direct Black dye. A laboratory scale experiment was conducted for maximum LiP production under optimal conditions. Purification & fractionation of LiP was performed on DEAE-Sepharose ion exchange chromatography followed by Sephadex G-50 gel filtration. The purified LiP has a specific activity of 519 U/mg with 6.73% activity recover. The optimum pH and temperature of purified LiP for the oxidation of veratryl alcohol were 6.8 and 45 °C, respectively. Michaelis-Menten kinetic constants (Vmax and Km) were determined using different concentrations of veratryl alcohol (1-35 mM). The Km and Vmax were 16.67 mM and 179.2 U/mL respectively, for veratryl alcohol oxidation as determined from the Lineweaver-Burk plot. Thermal inactivation studies were carried out at different temperatures to check the thermal stability of the enzyme. Enthalpy of activation decreased where Free energy of activation for thermal denaturation increased at higher temperatures. A possible explanation for the thermal inactivation of LiP at higher temperatures is also discussed.

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 PURIFICATION AND PARTIAL CHARACTERIZATION OF L-ASPARAGINASE ENZYME PRODUCED BY NEWLY ISOLATE BACILLUS SP.

2017 ◽  
Vol 18 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Dzun Noraini Jimat ◽  
Intan Baizura Firda Mohamed ◽  
Azlin Suhaida Azmi ◽  
Parveen Jamal
Keyword(s):  
Specific Activity ◽  
Hot Spring ◽  
Gel Filtration ◽  
Maximum Activity ◽  
Exchange Chromatography ◽  
Bacillus Sp ◽  
Sds Page ◽  
Fast Flow ◽  
Microbial Strain

A newly bacterial producing L-asparaginase was successful isolated from Sungai Klah Hot Spring, Perak, Malaysia and identified as Bacillus sp. It was the best L-asparaginase producer as compared to other isolates. Production of L-asparaginase from the microbial strain was carried out under liquid fermentation. The crude enzyme was then centrifuged and precipitated with ammonium sulfate before further purified with chromatographic method. The ion exchange chromatography HiTrap DEAE-Sepharose Fast Flow column followed by separation on Superose 12 gel filtration were used to obtain pure enzyme. The purified enzyme showed 10.11 U/mg of specific activity, 50.07% yield with 2.21 fold purification. The purified enzyme was found to be dimer in form, with a molecular weight of 65 kDa as estimated by SDS-PAGE. The maximum activity of the purified L-asparaginase was observed at pH 9 and temperature of 60°C.

scholarly journals Purification and Characterization of Endoglucanase from local isolate of Aspergillus flavus

2013 ◽  
Vol 10 (3) ◽  
pp. 844-853
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aspergillus Flavus ◽  
Specific Activity ◽  
Gel Filtration ◽  
Temperature Stability ◽  
Exchange Chromatography ◽  
Purification And Characterization ◽  
Original Activity ◽  
A Value ◽  
Optimum Ph

Endoglucanase produced from Aspergillus flavus was purified by several steps including precipitation with 25 % ammonium sulphate followed by Ion –exchange chromatography, the obtained specific activity was 377.35 U/ mg protein, with a yield of 51.32 % .This step was followed by gel filtration chromatography (Sepharose -6B), when a value of specific activity was 400 U/ mg protein, with a yield of 48 %. Certain properties of this purified enzyme were investigated, the optimum pH of activity was 7 and the pH of its stability was 4.5, while the temperature stability was 40 °C for 60 min. The enzyme retained 100% of its original activity after incubation at 40 °C for 60 min; the optimum temperature for enzyme activity was 40 °C.

scholarly journals Purification and Partial Characterization of β-Glucosidase from Fresh Leaves of Tea Plants (Camellia sinensis (L.) O. Kuntze)

2005 ◽  
Vol 37 (6) ◽  
pp. 363-370 ◽  
Author(s):  
Ye-Yun Li ◽  
Chang-Jun Jiang ◽  
Xiao-Chun Wan ◽  
Zheng-Zhu Zhang ◽  
Da-Xiang Li
Keyword(s):  
Specific Activity ◽  
Gel Filtration ◽  
Maximum Activity ◽  
Exchange Chromatography ◽  
Optimum Activity ◽  
Development Of Resistance ◽  
Sds Page ◽  
C 50 ◽  
Tea Plants

Abstractβ-Glucosidases are important in the formation of floral tea aroma and the development of resistance to pathogens and herbivores in tea plants. A novel β-glucosidase was purified 117-fold to homogeneity, with a yield of 1.26%, from tea leaves by chilled acetone and ammonium sulfate precipitation, ion exchange chromatography (CM-Sephadex C-50) and fast protein liquid chromatography (FPLC; Superdex 75, Resource S). The enzyme was a monomeric protein with specific activity of 2.57 U/mg. The molecular mass of the enzyme was estimated to be about 41 kDa and 34 kDa by SDS-PAGE and FPLC gel filtration on Superdex 200, respectively. The enzyme showed optimum activity at 50 °C and was stable at temperatures lower than 40 °C. It was active between pH 4.0 and pH 7.0, with an optimum activity at pH 5.5, and was fairly stable from pH 4.5 to pH 8.0. The enzyme showed maximum activity towards pNPG, low activity towards pNP-Galacto, and no activity towards pNP-Xylo.

scholarly journals Partial Chemical Characterization of S-Carboxymethylated Chains of Rabbit Fibrin(OGEN): Evidence for Separate Chain Biosynthesis

1977 ◽  
Author(s):  
B. Alving ◽  
G. Murano ◽  
D. Walz
Keyword(s):  
Amino Acid ◽  
Specific Activity ◽  
Chemical Characterization ◽  
Molecular Size ◽  
Exchange Chromatography ◽  
12 Steps ◽  
Polypeptide Chains ◽  
Sds Electrophoresis ◽  
Derivatives Of

The purpose of this study was twofold: 1) chemically characterize the isolated polypeptide chains of rabbit fibrin(ogen), and 2) explore their mode of biosynthesis. The three S-carboxy-methyl polypeptide chain derivatives of rabbit fibrin (α, β and γ) were isolated by cation exchange chromatography. Their amino acid composition was similar to the human with a methionine distribution (mole/mole) as follows: γ = 9; β = 14, α = 14. Their molecular size, (SDS electrophoresis) was estimated as follows: γ = 46,000; β = 54,000; α = 63,500. The N-terminal amino acid sequence (12 steps) of the β derivative was:Gly-His-Arg-Pro-Ile-Asp-Arg-Arg-Arg-Glu-Glu-Leu-. To determine whether the three chains are synthesized sequentially (one continuous chain, later split into three) or in parallel, turpentine-stimulated male New Zealand rabbits were given ~40 μCi of [75Se] selenomethionine (SeM) and its incorporation into fibrinogen (F) was followed. F was clotted from plasma samples, washed, reduced, and constituent chains separated by gel electrophoresis in the presence of SDS-urea. The radioactivity of each chain (expressed as percent of total F radioactivity) was determined, and the specific methionine radioactivity calculated for each chain isolated at 20, 25, and 30 min after SeM injection. During this interval the specific activity of the α and the γ chains was essentially the same (within 3%) while that of the β chain was 42 to 97% greater than that of the α chain. The similar activity of the α and γ chains during the early phase of SeM incorporation suggests that these two chains are not synthesized sequentially, rather they are synthesized in parallel.

scholarly journals Purification and Biochemical Characterization of Alkaline Serine Protease from Caesalpinia bonducella

2010 ◽  
Vol 5 (6) ◽  
pp. 1934578X1000500
Author(s):  
Hidayatullah Khan ◽  
Irshad Ali ◽  
Arif-ullah Khan ◽  
Mushtaq Ahmed ◽  
Zamarud Shah ◽  
...  
Keyword(s):  
Serine Protease ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Sodium Dodecyl ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Alkaline Serine Protease ◽  
Protease Enzyme ◽  
Caesalpinia Bonducella

A high molecular weight serine protease has been purified to electrophoretic homogeneity from the seeds of Caesalpinia bonducella Flem. (Caesalpiniaceae) by the combination of size exclusion and ion exchange chromatography. About 524 fold purification was achieved with an overall recovery of 6.8%. The specific activity was found to be 86 U/mg/min at pH 8.0. The calculated Km and Vmax were 1.66 mg/mL and 496.68 units/min per mg of protein, respectively. The molecular mass was estimated to be about 63 kDa by sodium dodecyl sulfate PAGE. The enzyme showed optimum activity at pH 8.0 and exhibited its highest activity at 40°C. The enzyme was strongly inhibited by 2mM phenylmethylsulfonyl fluoride (PMSF), suggesting the presence of a serine residue at the active site. PMSF showed a pure competitive type of inhibition with the serine protease enzyme. It was observed that enzyme activity was enhanced in the presence of dications and was active against a variety of modified substrates and natural proteins.

scholarly journals Purification and characterization of a digestive cysteine proteinase from the American lobster (Homarus americanus)

1989 ◽  
Vol 263 (2) ◽  
pp. 439-444 ◽  
Author(s):  
M V Laycock ◽  
T Hirama ◽  
S Hasnain ◽  
D Watson ◽  
A C Storer
Keyword(s):  
Proteinase Inhibitors ◽  
Cysteine Proteinase ◽  
Gel Filtration ◽  
Homarus Americanus ◽  
Exchange Chromatography ◽  
American Lobster ◽  
Digestive Juice ◽  
Effects Of Ph ◽  
Km Value

A new cysteine proteinase was isolated from the digestive juice of the American lobster (Homarus americanus). The enzyme was purified by a combination of affinity and ion-exchange chromatography and gel filtration. The cysteine proteinase accounted for 80% of the proteolytic activity in the lumen of the hepatopancreas. The most potent heavy-metal inhibitors were Hg, Cu, and Ag ions. Inhibition by organic proteinase inhibitors, including E-64 [L-trans-epoxysuccinyl-leucylamido-(4-guanidino)butane] and activation of the enzyme by 2-mercaptoethanol and dithiothreitol are characteristic of cysteine proteinases. Several similarities to papain are noted and include the N-terminal sequence, of which 22 of the first 28 amino acids are identical. Some notable differences are the higher Mr of 28,000 compared with 23,350 for papain, and the low isoelectric point (pI 4.5) of the lobster enzyme. The effects of pH and temperature on catalytic activity of the lobster proteinase were studied with benzyloxycarbonylalanine p-nitrophenyl ester as the substrate. The kcat./Km value was effectively temperature-independent between 10 and 60 degrees C. The pH-activity profile for the lobster enzyme revealed four apparent protonation states, of which only two are active.

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