Purification and properties of L-asparaginase of Erwinia aroideae

1972 ◽  
Vol 18 (12) ◽  
pp. 1953-1957 ◽  
Author(s):  
F. S. Liu ◽  
J. E. Zajic

The intracellular enzyme, L-asparaginase, from aerobically grown Erwinia aroideae NRRL B-138 has been purified and some of its properties studied. Sonic treatment permitted recovery of 95% of L-asparaginase from cells. The crude cell lysate was purified 167-fold by means of ammonium sulfate fractionation and column chromatography on hydroxylapatite–cellulose, and DEAE–Sephadex. The specific activity of the most active fraction of L-asparaginase is 256 IU/mg protein. The enzyme has a broad pH activity profile with maximum at pH 9.0–9.5. The optimum temperature for enzyme reaction was determined to be 41 °C. The apparent activation energy is 11 000 cal/mole. The molecular weight of L-asparaginase was estimated by gel filtration to be 108 000.

1992 ◽  
Vol 12 (1) ◽  
pp. 15-21
Author(s):  
S. Kojima ◽  
K. Nara ◽  
Y. Inada ◽  
S. Hirose ◽  
Y. Saito

Platelet aggregation activity due to platelet-activating factor (PAF) was detected at high molecular weight (HMW) and low molecular weight fractions after gel-filtration chromatography of cell lysate of endothelial cells. [3H]PAF added to the cell lysate was similarly distributed after chromatography. The radioactivity associated with HMW fraction was not reduced by digesting the lysate with trypsin, suggesting that PAF was not making complexes with proteins but was included in lipid vesicles in cell lysate. Further evidence showed that an unknown specific factor(s) was needed to form these PAF-containing lipid vesicles. Radioactivity was not found in HMW fraction when [3H]PAF was mixed with cell lysate of vascular smooth muscle cells. When monomeric PAF was added to endothelial cell lysate, the specific activity of aggregation decreased to the level exerted by endogenous PAF-containing lipid vesicles due to incorporation into lipid vesicles. PAF in the form of lipid vesicles was more stable in plasma than monomeric form.


2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Marcin Grąz ◽  
Kamila Rachwał ◽  
Radosław Zan ◽  
Anna Jarosz-Wilkołazka

Oxalate oxidase was identified in mycelial extracts of a basidiomycete Abortiporus biennis strain. Intracellular enzyme activity was detected only after prior lowering of the pH value of the fungal cultures by using oxalic or hydrochloric acids. This enzyme was purified using size exclusion chromatography (Sephadex G-25) and ion-exchange chromatography (DEAE-Sepharose). This enzyme exhibited optimum activity at pH 2 when incubated at 40°C, and the optimum temperature was established at 60°C. Among the tested organic acids, this enzyme exhibited specificity only towards oxalic acid. Molecular mass was calculated as 58 kDa. The values of Km for oxalate and Vmax for the enzyme reaction were 0.015 M and 30 mmol min-1, respectively.


1961 ◽  
Vol 7 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Hans H. Gadebusch ◽  
John D. Johnson

A partially purified intracellular enzyme from a species of Alcaligenes is described which specifically initiates the degradation of the he heteropolysaccharide of Cryptococcus neoformans, isolate 3723, The enzyme is active in the presence of serum and can be inactivated by heating at 45 °C for 10 minutes, The kinetics of the enzyme reaction are similar to those of other enzymes. Recovery and identification of the four known monosaccharides from enzymatic hydrolyzates suggest the presence of a number of other enzymes in these preparations.


1977 ◽  
Vol 37 (03) ◽  
pp. 556-565 ◽  
Author(s):  
S. E Papaioannou ◽  
W. J Marsheck

SummaryAn extracellular protease SN 687, secreted by the soil bacterium isolate WM 122, has been purified by means of gel filtration, ammonium sulfate precipitation, DEAE-Sephadex and hydroxylapatite chromatography. Apparent homogeneity was ascertained by Polyacrylamide gel electrophoresis. The protease was inactivated by ethylenediamine tetracetic acid (EDTA) but not by diisopropylfluorophosphate (DFP), and it was partially inhibited by serum inhibitors. SN 687 was shown to be of high specific activity against casein and fibrin, but it did not hydrolyze L- lysine -methyl ester dihydrochloride (LME), p-tosyl-L-arginine-methyl ester hydrochloride (TAME) and N-benzoyl-L-tyrosine-ethyl ester hydrochloride (BTEE) synthetic substrates. The optimum pH for hydrolysis of casein was 7.5 and the molecular weight, as determined by gel filtration, was 31,000.


2009 ◽  
Vol 4 (1) ◽  
pp. 68-73 ◽  
Author(s):  
Gražina Giedraityte ◽  
Lilija Kalėdienė

AbstractThe purpose of this study was purification and characterization of catechol 1,2-dioxygenase from Geobacillus sp. G27 strain, which degrades α-naphthol by the β-ketoadipate pathway. The catechol 1,2-dioxygenase (C1,2O) was purified using four steps of ammonium sulfate precipitation, DEAE-celullose, Sephadex G-150 and hydroxylapatite chromatographies. The enzyme was purified about 18-fold with a specific activity of 7.42 U mg of protein−1. The relative molecular mass of the native enzyme estimated on gel chromatography of Sephadex G-150 was 96 kDa. The pH and temperature optima for enzyme activity were 7 and 60°C, respectively. A half-life of the catechol 1,2-dioxygenase at the optimum temperature was 40 min. The kinetic parameters of the Geobacillus sp. G27 strain catechol 1,2-dioxygenase were determined. The enzyme had apparent Km of 29 µM for catechol and the cleavage activities for methylcatechols were much less than for catechol and no activity with gentisate or protocatechuate was detected.


1985 ◽  
Vol 63 (11) ◽  
pp. 1160-1166 ◽  
Author(s):  
Pierre Gondé ◽  
Robert Ratomahenina ◽  
Alain Arnaud ◽  
Pierre Galzy

The exocellular enzyme β-glucosidase of Candida molischiana was studied. This strain is able to ferment soluble cellodextrins. The enzyme was partially purified by ion-exchange chromatography and gel filtration. The molecular weight of this enzyme was 120 000; its optimum pH was between 4 and 4.5 and its optimum temperature was 60 °C. This enzyme was active against different soluble glucosides and was inhibited by p-chloromercuribenzoate, gluconolactone, and glucose. A "glucosyltransferase" activity appeared in the presence of ethanol. The biosynthesis of the enzyme was constitutive but repressed by glucose.


1972 ◽  
Vol 50 (4) ◽  
pp. 352-362 ◽  
Author(s):  
V. S. Gupta ◽  
J. B. Meldrum

Thymidylate synthetase of pig thymus has been separated into two principal forms (designated I and II, based on their order of elution) by chromatography on CM-Sephadex. By the use of (NH4)2SO4 the synthetase activity was separated into two fractions, and these were further purified by gel filtration using Sephadex G-100 and chromatography on CM-Sephadex. The highest specific activity obtained for I and II was 10.4 and 16.3 μmol of thymidine-5′-phosphate per hour per milligram of protein at 25° and pH 7.3 which represents a purification of 1680- and 2630-fold, respectively. Electrophoretically, I and II appear to be 70–80% pure. The Michaelis constants of 7.4 × 10−6 M, 1.7 × 10−5 M, and 1.8 × 10−4 M for II with respect to deoxyuridine-5′-phosphate, 5,10-methlenetetrahydrofolate, and uridine-5′-phosphate, respectively, have been determined. A double pH optima in the range of 6.6–6.8 and 7.2–7.4 in 2-N-morpholinoethane sulfonic acid buffer was exhibited by both forms. Forms I and II showed maximal catalytic activity only in the presence of sulfhydryl compounds (60 mM) and also had the ability to methylate uridine-5′-phosphate, although at a slower rate (ca. 28% and 13%, respectively) compared with the rate of methylation of deoxyuridine-5′-phosphate. Both deoxyuridine-5′-phosphate and tetrahydrofolate (to a lesser extent) afforded protection to II against heat inactivation.


1975 ◽  
Vol 151 (2) ◽  
pp. 263-270 ◽  
Author(s):  
S A Betts ◽  
R J Mayer

1. 6-Phosphogluconate dehydrogenase from rabbit mammary gland was purified to homogeneity by the criterion of polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. The molecular weight of the subunit is 52 000. The enzyme was purified 150-fold with a final specific activity of 20 mumol of NADP+ reduced/min per mg of protein and overall yield of 3%. The molecular weight of the native enzyme is estimated to be 104 000 from gel-filtration studies. The final purification step was carried out by affinity chromatography with NADP+-Sepharose. 2. The Km values for 6-phosphogluconate and NADP+ are approx. 54 muM and 23 muM respectively. 3. Citrate and pyrophosphate are competitive inhibitors of the enzyme with respect to both 6-phosphogluconate and NADP+. 4. MgCl2 affects the apparent Km for NADP+ at saturating concentrations of 6-phosphogluconate.


2007 ◽  
Vol 13 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Elidar Naiola ◽  
Nunuk Widhyastuti

The aim of the research was to find the partial purified of enzyme protease from Bacillus sp. The crude enzyme of protease was produce in rice brand medium (100 gram of rice brand in a liter tofu liquid waste). The enzyme was semi-purified by the procedure of precipitation using ethanol in different percentages of saturation, gel filtration using Sephadex G 100 and Ion Exchanged Chromatography using DEAE Sephadex A50. Specific activities of the enzyme during purification were 5.71 U/mg (crude enzyme); 6.75 U/mg (ethanol precipitations); 37.16 U/mg (gel filtration) and 43.02 U/mg (Ion Exchanged Chromatography). The optimum temperature for enzyme reaction was 45–50 °C, while the optimum pH was 7.0–8.0. Protease was relatively stable after heating until 37–50 °C for 60 minutes. Metal ions had different effects to the enzyme. CaCl2, FeCl3, MnCl2, ZnCl2 and MgCl2 increased enzyme activity, CdCl2 and HgCl2 gave an inhibitory effect, and another of metal ions had no effects to the enzyme.


2011 ◽  
Vol 14 (3) ◽  
pp. 5-11
Author(s):  
Thy Bao Vuong ◽  
Lam Bich Tran ◽  
Duan Luu

Lipase from the hepatopancreas of Tra (Pangasius) catfish was purified by ammonium sulfate fractionation, followed by ion-exhange chromatography on DEAE Cellulose and gel filtration Sephadex G-75. The preparation was homogeneous on polyacrylamide disc gel electrophoresis. The specific activity of the purified enzyme was 37.95 times higher than that of the crude extract. The enzyme showed a molecular weight of 57000 Da. The pH and temperature optima of purified lipase were 8 and 500C respectively. Enzyme activity was enhanced by Ca2+ but inhibited by heavy metals Zn2+, Cd2+, Mg2+.


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