scholarly journals Purification and Characterization of Asparaginase fromPhaseolus vulgarisSeeds

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Saleh A. Mohamed ◽  
Mohamed F. Elshal ◽  
Taha A. Kumosani ◽  
Alia M. Aldahlawi

L-asparaginase from bacteria has been used in treatment of acute lymphoblastic leukemia. The aim of this study was to purify and characterize L-asparaginase fromPhaseolus vulgarisseeds instead of microbial sources. L-asparaginase was purified to apparent homogeneity. The enzyme has molecular mass of 79 kDa. The purified asparaginase had very low activity toward a number of asparagine and glutamine analogues. L-asparaginase was free from glutaminase activity. Kinetic parameters, Km andVmax of purified enzyme, were found to be 6.72 mM and 0.16 μM, respectively. The enzyme had optimum pH at 8.0. The enzyme showed high stability at alkaline pH (pH 7.5–9.0) when incubated for up to 24 h. L-asparaginase had the same temperature optimum and thermal stability at 37°C. K+was able to greatly enhance the activity of asparaginase by 150% compared with other metals tested. In conclusion, L-asparaginase showed no glutaminase activity and good stability over a wide range of physiological conditions, and thus it could be used as a potential candidate for treatment of acute lymphoblastic leukemia.

1988 ◽  
Vol 66 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Eduardo T. Cánepa ◽  
Elena B.C. Llambías

Pig liver ferrochelatase was purified 465-fold with about 30% yield, to apparent homogeneity, by a procedure involving solubilization from mitochondria, ammonium sulfate fractionation, and Sephacryl S-300 chromatography. The fraction of each purification step had cobaltochelatase as well as ferrochelatase activity. A purified protein of molecular weight 40 000 was found by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. A molecular weight of approximately 240 000 was obtained by Sephacryl S-300 chromatography. Both activities of the purified fraction increased linearly with time until 2 h. but nonlinear plots were obtained with increasing concentrations of protein. Their optimum pH values were similar. Km values were, for ferrochelatase activity, 23.3 μM for the metal and 30.3 μM for mesoporphyrin. and for cobaltochelatase activity. 27 and 45.5 μM, respectively. Fe2+ and Co2+ each protected against inactivation by heat. Pb2+, Zn2+, Cu2+, or Hg2+ inhibited both activities, while Mn2+ slightly activated; Mg2+ had no effect, at the concentrations tested. There appeared to be an involvement of sulfhydryl groups in metal insertion. Lipids, in correlation with their degree of unsaturation, activated both purified activities; phospholipids also had activation effects. We conclude that a single protein catalyzes the insertion of Fe2+ or Co2+ into mesoporphyrin.


2009 ◽  
Vol 221 (03) ◽  
Author(s):  
R Vagkopoulou ◽  
C Eckert ◽  
U Ungethüm ◽  
G Körner ◽  
M Stanulla ◽  
...  

Leukemia ◽  
2020 ◽  
Vol 34 (10) ◽  
pp. 2785-2789
Author(s):  
Peter Horak ◽  
Sebastian Uhrig ◽  
Maximilian Witzel ◽  
Irene Gil-Farina ◽  
Barbara Hutter ◽  
...  

1992 ◽  
Vol 282 (3) ◽  
pp. 711-714 ◽  
Author(s):  
E Blée ◽  
F Schuber

Epoxide hydrolases catalysing the hydration of cis-9,10-epoxystearate into threo-9,10-dihydroxystearate have been detected in soybean (Glycine max) seedlings. The major activity was found in the cytosol, a minor fraction being strongly associated with microsomes. The soluble enzyme, which was purified to apparent homogeneity by (NH4)2SO4 fractionation, hydrophobic, DEAE- and gel-filtration chromatographies, has a molecular mass of 64 kDa and a pI of 5.4.


1996 ◽  
Vol 20 (4) ◽  
pp. 349-355 ◽  
Author(s):  
Eduardo M. Rego ◽  
Aglair B. Garcia ◽  
Sonia R. Viana ◽  
Roberto P. Falcão

1992 ◽  
Vol 288 (2) ◽  
pp. 475-482 ◽  
Author(s):  
I Ishii-Karakasa ◽  
H Iwase ◽  
K Hotta ◽  
Y Tanaka ◽  
S Omura

For the purification of a new type of endo-alpha-N-acetylgalactosaminidase from the culture medium of Streptomyces sp. OH-11242 (endo-GalNAc-ase-S) [Iwase, Ishii, Ishihara, Tanaka, Omura & Hotta (1988) Biochem. Biophys. Res. Commun. 151, 422-428], a method for assaying enzyme activity was established. Using purified pig gastric mucus glycoprotein (PGM) as the substrate, oligosaccharides liberated from PGM were pyridylaminated, and the reducing terminal sugars of oligosaccharides larger than Gal beta 1-3GalNAc were analysed by h.p.1.c. The crude enzyme of endo-GalNAc-ase-S was prepared as an 80% (w/v) ammonium sulphate precipitate from the concentrated culture medium. The enzyme was partially purified by gel chromatofocusing and subsequent DEAE-Toyopearl chromatography. Endo-enzyme activity eluted around pI 4.8 on a gel chromatofocusing column and eluted with 0.19-0.25 M-NaCl on a DEAE-Toyopearl column. In the enzyme fraction obtained, no exo-glycosidases or proteases could be detected. The molecular mass of the enzyme was estimated as 105 kDa by gel filtration, and the optimum pH was 5.5. Endo-GalNAc-ase-S hydrolysed the O-glycosidic linkage between GalNAc and Ser (Thr) in 3H-labelled and unlabelled asialofetuin, liberating both the disaccharide (Gal beta 1-3GalNAc) and the tetrasaccharide [Gal beta 1-3 (Gal beta 1-4GlcNAc beta 1-6)GalNAc]. When endo-alpha-N-acetylgalactosaminidase from Alcaligenes sp. (endo-GalNac-ase-A) was incubated with 3H-labelled and unlabelled asialofetuin, only the disaccharide (Gal beta 1-3GalNAc) was liberated.


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