Partial purification and characterization of phosphoenolpyruvate carboxylase from the cyanobacterium Anabaena variabilis

1986 ◽  
Vol 64 (5) ◽  
pp. 427-433 ◽  
Author(s):  
Nora W. Lem ◽  
Donna M. Penrose ◽  
Bernard R. Glick
Keyword(s):  
Enzyme Activity ◽  
Molecular Mass ◽  
Polyacrylamide Gel Electrophoresis ◽  
Anabaena Variabilis ◽  
Partial Purification ◽  
Purification And Characterization ◽  
Carboxylase Activity ◽  
Pep Carboxylase ◽  
Cyanobacterium Anabaena

The partial purification and characterization of phosphoenolpyruvate (PEP) carboxylase from the cyanobacterium Anabaena variabilis is reported. Spheroplasts made from photoautotrophically grown cells were lysed to produce a crude cell extract which was fractionated by (i) (NH4)2SO4 precipitation and (ii) gel filtration through Sephacryl S-300. The peak of enzyme activity that was eluted from the column corresponded to a molecular mass of approximately 365 000 daltons; the molecular mass of the sub-units was found to be approximately 100 500 daltons as assessed by polyacrylamide gel electrophoresis. The pH optimum for PEP carboxylase activity was pH 7.0. The response of this A. variabilis enzyme to effectors distinguished this enzyme from that found in C3 plants and in bacteria. Malate inhibited enzyme activity but was a much more effective inhibitor at pH 7.0 (50% inhibition at 1.6 mM malate) than at pH 8.0 (15% inhibition at 10 mM malate). Glycine stimulated PEP carboxylase activity at both pH 7.0 and 8.0, while glucose 6-phosphate had no significant effect. The Km for HCO3− was calculated to be 14.5 ± 9.2 μM. These results suggest that PEP carboxylase from A. variabilis is kinetically similar to maize PEP carboxylase and may participate in inorganic carbon uptake for photosynthesis.

scholarly journals Partial purification and characterization of an endo-α-N-acetylgalactosaminidase from the culture medium of Streptomyces sp. OH-11242

1992 ◽  
Vol 288 (2) ◽  
pp. 475-482 ◽  
Author(s):  
I Ishii-Karakasa ◽  
H Iwase ◽  
K Hotta ◽  
Y Tanaka ◽  
S Omura
Keyword(s):  
Enzyme Activity ◽  
Culture Medium ◽  
Gel Filtration ◽  
Partial Purification ◽  
Gastric Mucus ◽  
Purification And Characterization ◽  
Streptomyces Sp ◽  
Optimum Ph ◽  
New Type

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.

scholarly journals Optimization of Growth Conditions for Purification and Production of L-Asparaginase bySpirulina maxima

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hanaa H. Abd El Baky ◽  
Gamal S. El Baroty
Keyword(s):  
Enzyme Activity ◽  
Gel Filtration ◽  
Growth Conditions ◽  
Partial Purification ◽  
Specific Enzyme ◽  
Purification And Characterization ◽  
Spirulina Maxima ◽  
Optimum Ph ◽  
Biomass Yields

L-asparaginase (L-AsnA) is widely distributed among microorganisms and has important applications in medicine and in food technology sectors. Therefore, the ability of the production, purification, and characterization of AsnA fromSpirulina maxima(SM) were tested. SM cultures grown in Zarrouk medium containing different N2(in NaNO3form) concentrations (1.25, 2.50, and 5.0 g/L) for 18 days contained a significant various quantity of dry biomass yields and AsnA enzyme levels. MS L-AsnA activity was found to be directly proportional to the N2concentration. The cultures of SM at large scales (300 L medium, 5 g/L N2) showed a high AsnA enzyme activity (898 IU), total protein (405 mg/g), specific enzyme activity (2.21 IU/mg protein), and enzyme yield (51.28 IU/L) compared with those in low N2cultures. The partial purification of crude MS AsnA enzyme achieved by 80% ammonium sulfate AS precipitated and CM-Sephadex C-200 gel filtration led to increases in the purification of enzyme with 5.28 and 10.91 times as great as that in SM crude enzymes. Optimum pH and temperature of purified AsnA for the hydrolyzate were 8.5 and 37 ± 0.2°C, respectively. To the best of our knowledge, this is the first report on L-asparaginase production inS. maxima.

scholarly journals Innate Immunity in Lobsters: Partial Purification and Characterization of a Panulirus cygnus Anti-A Lectin

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Robert L. P. Flower
Keyword(s):  
Innate Immunity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Spiny Lobster ◽  
Gel Filtration ◽  
Partial Purification ◽  
Purification And Characterization ◽  
Rat Erythrocytes ◽  
Group A ◽  
Panulirus Cygnus

A lectin detected in haemolymph from the Australian spiny lobster Panulirus cygnus agglutinated human ABO Group A cells to a higher titre than Group O or B. The lectin also agglutinated rat and sheep erythrocytes, with reactivity with rat erythrocytes strongly enhanced by treatment with the proteolytic enzyme papain, an observation consistent with reactivity via a glycolipid. The lectin, purified by affinity chromatography on fixed rat-erythrocyte stroma, was inhibited equally by N-acetylglucosamine and N-acetylgalactosamine. Comparison of data from gel filtration of haemolymph (behaving as a 1,800,000 Da macromolecule), and polyacrylamide gel electrophoresis of purified lectin (a single 67,000 Da band), suggested that in haemolymph the lecin was a multimer. The purified anti-A lectin autoprecipitated unless the storage solution contained chaotropic inhibitors (125 mmol/L sucrose: 500 mmol/L urea). The properties of this anti-A lectin and other similar lectins are consistent with a role in innate immunity in these invertebrates.

scholarly journals Human liver N-acetylglucosamine-6-sulphate sulphatase. Purification and characterization

1987 ◽  
Vol 246 (2) ◽  
pp. 347-354 ◽  
Author(s):  
C Freeman ◽  
P R Clements ◽  
J J Hopwood
Keyword(s):  
Enzyme Activity ◽  
Culture Medium ◽  
Large Subunit ◽  
Polyacrylamide Gel Electrophoresis ◽  
Purification And Characterization ◽  
Isolation And Characterization ◽  
Molecular Masses ◽  
Single Polypeptide ◽  
Column Procedure

Human N-acetylglucosamine-6-sulphate sulphatase was purified at least 50,000-fold to homogeneity in 78% yield from liver with a simple three-step four-column procedure, which consists of a concanavalin A-Sepharose/Blue A-agarose coupled step, chromatofocusing and Cu2+-chelating Sepharose chromatography. In all, four forms were isolated and partially characterized. Forms A and B, both with a pI greater than 9.5 and representing 30% and 60% respectively of the recovered enzyme activity, were separated by hydroxyapatite chromatography of the enzyme preparation obtained from the Cu2+-chelating Sepharose step. Both forms A and B had native molecular masses of 75 kDa. When analysed by SDS/polyacrylamide-gel electrophoresis, form A consists of a single polypeptide of molecular mass 78 kDa, whereas form B contained 48 kDa and 32 kDa polypeptide subunits. Neither form A nor form B was taken up from the culture medium into cultured human skin fibroblasts. The two other forms (C and D), with pI values of 5.8 and 5.4 respectively, represented approx. 7% and 3% of the total recovered enzyme activity. The native molecular masses of forms C and D were 94 kDa and approx. 75 kDa respectively. Form C contained three polypeptides with molecular masses of 48, 45 and 32 kDa. N-Acetylglucosamine-6-sulphate sulphatase activity was measured with a radiolabelled disaccharide substrate derived from heparin. The development of this substrate enabled the isolation and characterization of N-acetylglucosamine-6-sulphate sulphatase to proceed efficiently. Forms A, B and C had pH optima of 5.0, Km values of 11.7, 14.2 and 11.1 microM respectively and Vmax. values of 105, 60 and 53 nmol/min per mg of protein respectively. The molecular basis of the multiple forms of this sulphatase is not known. It is postulated that the differences in structure and properties of the four enzyme forms are due to differences in the state of processing of a large subunit.

Partial Purification and Characterization of Membrane-Associated 3-Hydroxy-3-methylglutaryl-Coenzyme A Lyase from Radish Seedlings

1993 ◽  
Vol 48 (5-6) ◽  
pp. 444-450 ◽  
Author(s):  
Thomas Weber ◽  
Thomas J. Bach
Keyword(s):  
Activation Energy ◽  
Molecular Mass ◽  
Coenzyme A ◽  
Arrhenius Plot ◽  
Linear Part ◽  
Partial Purification ◽  
Purification And Characterization ◽  
Ph Optimum ◽  
Radish Seedlings

Abstract We solubilized from radish membranes and purified by 154-fold 3-hydroxy-3-methyl-glutaryl-CoA lyase (HMGL, EC 4.1.3.4) catalyzing the conversion of 3-hydroxy-3-methyl-glutaryl-(HMG -)CoA into acetyl-CoA and acetoacetate. The apparent molecular mass under non-denaturating conditions is 70 kDa. The enzyme has a broad pH optimum around 8.0 and its activation energy as determined from the linear part of an Arrhenius plot is 137.1 kJ/mol. The Km with respect to (5)-H MG-CoA is 40 μM . The enzyme is extremely unstable and rapidly loses activity even when kept on ice, but retains some activity over several weeks when stored at -80 °C.

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.

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