scholarly journals A Sequence-Specific Nicking Endonuclease from Streptomyces: Purification, Physical and Catalytic Properties

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Peechapack Somyoonsap ◽  
Vichein Kitpreechavanich ◽  
Somchai Pornbanlualap

A sequence-specific nicking endonuclease from Streptomyces designated as DC13 was purified to near homogeneity. Starting with 30 grams of wet cells, the enzyme was purified by ammonium sulfate fractionation, DEAE cellulose, and phenyl-Sepharose chromatography. The purified protein had a specific activity 1000 units/mg and migrated on SDS-PAGE gel with an estimated molecular weight of 71 kDa. Determination of subunit composition by gel filtration chromatography indicated that the native enzyme is a monomer. When incubated with different DNA substrates including pBluescript II KS, pUC118, pET-15b, and pET-26b, the enzyme converted these supercoiled plasmids to a mixture of open circular and linear DNA products, with the open circular DNA as the major cleavage product. Analysis of the kinetic of DNA cleavage showed that the enzyme appeared to cleave super-coiled plasmid in two distinct steps: a rapid cleavage of super-coiled plasmid to an open circular DNA followed a much slower step to linear DNA. The DNA cleavage reaction of the enzyme required Mg2+ as a cofactor. Based on the monomeric nature of the enzyme, the kinetics of DNA cleavage exhibited by the enzyme, and cofactor requirement, it is suggested here that the purified enzyme is a sequence-specific nicking endonuclease that is similar to type IIS restriction endonuclease.

2003 ◽  
Vol 69 (12) ◽  
pp. 7116-7123 ◽  
Author(s):  
Ho-Young Shin ◽  
Sun-Young Park ◽  
Jong Hwan Sung ◽  
Dong-Hyun Kim

ABSTRACT Two arabinosidases, α-l-arabinopyranosidase (no EC number) and α-l-arabinofuranosidase (EC 3.2.1.55), were purified from ginsenoside-metabolizing Bifidobacterium breve K-110, which was isolated from human intestinal microflora. α-l-Arabinopyranosidase was purified to apparent homogeneity, using a combination of ammonium sulfate fractionation, DEAE-cellulose, butyl Toyopearl, hydroxyapatite Ultrogel, QAE-cellulose, and Sephacryl S-300 HR column chromatography, with a final specific activity of 8.81 μmol/min/mg.α -l-Arabinofuranosidase was purified to apparent homogeneity, using a combination of ammonium sulfate fractionation, DEAE-cellulose, butyl Toyopearl, hydroxyapatite Ultrogel, Q-Sepharose, and Sephacryl S-300 column chromatography, with a final specific activity of 6.46 μmol/min/mg. The molecular mass ofα -l-arabinopyranosidase was found to be 310 kDa by gel filtration, consisting of four identical subunits (77 kDa each, measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE]), and that ofα -l-arabinofuranosidase was found to be 60 kDa by gel filtration and SDS-PAGE. α-l-Arabinopyranosidase and α-l-arabinofuranosidase showed optimal activity at pH 5.5 to 6.0 and 40°C and pH 4.5 and 45°C, respectively. Both purified enzymes were potently inhibited by Cu2+ and p-chlormercuryphenylsulfonic acid.α -l-Arabinopyranosidase acted to the greatest extent on p-nitrophenyl-α-l-arabinopyranoside, followed by ginsenoside Rb2. α-l-Arabinofuranosidase acted to the greatest extent on p-nitrophenyl-α-l-arabinofuranoside, followed by ginsenoside Rc. Neither enzyme acted on p-nitrophenyl-β-galactopyranoside or p-nitrophenyl-β-d-fucopyranoside. These findings suggest that the biochemical properties and substrate specificities of these purified enzymes are different from those of previously purified α-l-arabinosidases. This is the first reported purification ofα -l-arabinopyranosidase from an anaerobic Bifidobacterium sp.


2012 ◽  
Vol 61 (1) ◽  
pp. 51-55 ◽  
Author(s):  
PONNUSWAMY VIJAYARAGHAVAN ◽  
S.G. PRAKASH VINCENT

A microorganism hydrolyzing carboxymethyl cellulose was isolated from a paddy field and identified as Bacillus sp. Production of cellulase by this bacterium was found to be optimal at pH 6.5, 37 degrees C and 150 rpm of shaking. This cellulase was purified to homogeneity by the combination of ammonium sulphate precipitation, DEAE cellulose, and sephadex G-75 gel filtration chromatography. The cellulase was purified up to 14.5 fold and had a specific activity of 246 U/mg protein. The enzyme was a monomeric cellulase with a relative molecular mass of 58 kDa, as determined by SDS-PAGE. The enzyme exhibited its optimal activity at 50 degrees C and pH 6.0. The enzyme was stable in the pH range of 5.0 to 7.0 and its stability was maintained for 30 min at 50 degrees C and its activity got inhibited by Hg2+, Cu2+, Zn2+, Mg2+, Na2+, and Ca2+.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mahmoud A. Ibrahim ◽  
Abdel-Hady M. Ghazy ◽  
Ahmed M. H. Salem ◽  
Mohamed A. Ghazy ◽  
Mohamed M. Abdel-Monsef

Glucose-6-phosphate dehydrogenase from camel liver was purified to homogeneity by ammonium sulfate precipitation and a combination of DEAE-cellulose, Sephacryl S-300 gel filtration, and 2′, 5′ ADP Sepharose 4B affinity chromatography columns. The specific activity of camel liver G6PD is increased to 1.80438 units/mg proteins with 63-fold purification. It turned out to be homogenous on both native PAGE and 12% SDS PAGE, with a molecular weight of 64 kDa. The molecular weight of the native form of camel liver G6PD was determined to be 194 kDa by gel filtration indicating a trimeric protein. The Km value was found to be 0.081 mM of NADP+. Camel liver G6PD displayed its optimum activity at pH 7.8 with an isoelectric point (pI) of pH 6.6–6.8. The divalent cations MgCl2, MnCl2, and CoCl2 act as activators; on the other hand, CaCl2 and NiCl2 act as moderate inhibitors, while FeCl2, CuCl2, and ZnCl2 are potent inhibitors of camel liver G6PD activity. NADPH inhibited camel liver G6PD competitively with Ki value of 0.035 mM. One binding site was deduced for NADPH on the enzyme molecule. This study presents a simple and reproducible purification procedure of G6PD from the camel liver.


2021 ◽  
Vol 9 (2) ◽  
pp. 24-30

Streptokinase is a fibrinolytic enzyme and a product of β-hemolytic Streptococci strains. This enzyme is used as a medication to break down clots in some cases of heart disease. Streptococcus equisimilis, a species of group C Streptococci, is widely used for the production of streptokinase by fermentation technology. In this study, the sugarcane bagasse fermentation medium was optimized for metal ions (KH2PO4, MgSO4.7H2O, CaCO3 and NaHCO3) at various levels to attain the maximal production of streptokinase. Sugarcane bagasse was used due to its profuse availability and as an ideal substrate for microbial processes for the manufacturing of value-added products. The results showed that maximal streptokinase production was found at 0.04% KH2PO4, 0.04% MgSO4.7H2O, 0.15% NaHCO3 and 0.04% CaCO3. Finally, the optimized medium resulted in 84.75 U/mg specific activity and 74.5% recovery. The purification process was carried out simultaneously using ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration. Finally, a purified sample of streptokinase was run on SDS-PAGE and resolute 47 kDa molecular weight. The use of β-hemolytic Streptococci to obtain streptokinase is not free from health risks and is related to anaphylaxis. This study provides a way forward for the cost-effective ways to obtain streptokinase for the treatment of thrombosis.


2017 ◽  
Vol 18 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Dzun Noraini Jimat ◽  
Intan Baizura Firda Mohamed ◽  
Azlin Suhaida Azmi ◽  
Parveen Jamal

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.


2000 ◽  
Vol 352 (3) ◽  
pp. 875-882 ◽  
Author(s):  
William L. TURNER ◽  
William C. PLAXTON

Cytosolic pyruvate kinase (PKc) from ripened banana (Musa cavendishii L.) fruits has been purified 543-fold to electrophoretic homogeneity and a final specific activity of 59.7µmol of pyruvate produced/min per mg of protein. SDS/PAGE and gel-filtration FPLC of the final preparation indicated that this enzyme exists as a 240kDa homotetramer composed of subunits of 57kDa. Although the enzyme displayed a pH optimum of 6.9, optimal efficiency in substrate utilization [in terms of Vmax/Km for phosphoenolpyruvate (PEP) or ADP] was equivalent at pH6.9 and 7.5. PKc activity was absolutely dependent upon the presence of a bivalent and a univalent cation, with Mg2+ and K+ respectively fulfilling this requirement. Hyperbolic saturation kinetics were observed for the binding of PEP, ADP, Mg2+ and K+ (Km values of 0.098, 0.12, 0.27 and 0.91mM respectively). Although the enzyme utilized UDP, IDP, GDP and CDP as alternative nucleotides, ADP was the preferred substrate. L-Glutamate and MgATP were the most effective inhibitors, whereas L-aspartate functioned as an activator by reversing the inhibition of PKc by L-glutamate. The allosteric features of banana PKc are compared with those of banana PEP carboxylase [Law and Plaxton (1995) Biochem. J. 307, 807Ő816]. A model is presented which highlights the roles of cytosolic pH, MgATP, L-glutamate and L-aspartate in the co-ordinate control of the PEP branchpoint in ripening bananas.


1996 ◽  
Vol 319 (3) ◽  
pp. 977-983 ◽  
Author(s):  
Jeong Heon KO ◽  
Cheorl Ho KIM ◽  
Dae-Sil LEE ◽  
Yu Sam KIM

An extremely thermostable ADP-glucose pyrophosphorylase (AGPase) has been purified from Thermus caldophilus GK-24 to homogeneity by chromatographic methods, including gel filtration and ion-exchange and affinity chromatography. The specific activity of the enzyme was enriched 134.8-fold with a recovery of 10.5%. The purified enzyme was a single band by SDS/PAGE with a molecular mass of 52 kDa. The homotetrameric structure of the native enzyme was determined by gel filtration analysis, which showed a molecular mass of 230 kDa on a Superose-12 column, indicating that the structure of the enzyme is different from the heterotetrameric structures of higher-plant AGPases. The enzyme was most active at pH 6.0. The activity was maximal at 73–78 °C and its half-life was 30 min at 95 °C. Kinetic and regulatory properties were characterized. It was found that AGPase activity could be stimulated by a number of glycolytic intermediates. Fructose 6-phosphate, fructose 1,6-bisphosphate, phenylglyoxal and glucose 6-phosphate were effective activators, of which fructose 1,6-bisphosphate was the most effective. The enzyme was inhibited by phosphate, AMP or ADP. ATP and glucose 1-phosphate gave hyperbolic-shaped rate-concentration curves in the presence or absence of activator. A remarkable aspect of the amino acid composition was the existence of the hydrophobic and Ala+Gly residues. The N-terminal and internal peptide sequences were determined and compared with known sequences of various sources. It was apparently similar to those of AGPases from other bacterial and plant sources, suggesting that the enzymes are structurally related.


2005 ◽  
Vol 37 (6) ◽  
pp. 363-370 ◽  
Author(s):  
Ye-Yun Li ◽  
Chang-Jun Jiang ◽  
Xiao-Chun Wan ◽  
Zheng-Zhu Zhang ◽  
Da-Xiang Li

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.


1977 ◽  
Author(s):  
F.S. Markland ◽  
J. Chou ◽  
Y. Shih ◽  
H. Pirkle

A new procedure has been developed for large scale, rapid purification of crotalase, the thrombin-1ike enzyme from the venom of the eastern diamondback rattlesnake (Crotalus adamanteus). The three step procedure involves: (1) molecular sieve chromatography on Sephadex G-100 in 0.04 M Tris buffer containing 0.10 M sodium chloride, pH 7.1; (2) gradient elution from DEAE-cellulose with sodium acetate buffer, pH 7.0; and (3) affinity chromatography on p-aminobenzamidine Sepharose using a spacer of 6-aminohexanoic acid. Crotalase was eluted from the affinity resin by 0.05 M Tris buffer containing 0.10 M sodium chloride and 0.15 M benzamidine-hydrochloride, pH 9.0, after first washing with the Tris buffer containing 0.40 M sodium chloride. From the crude venom, pure enzyme was obtained with an overall recovery of 40-60% of clotting activity and a 90-100 fold increase in specific activity. Crotalase was shown to be pure by Polyacrylamide disk gel electrophoresis which gave one band. The molecular weight was estimated to be approximately 31,000 by gel filtration on a calibrated Sephadex G-100 column. Amino acid analysis was performed and the composition was shown to be very similar to that reported earlier (F.S. Markland and P.S. Damus, J. Biol. Chem. 246: 6460, 1971). Clotting activity of the enzyme was not inhibited by heparin, either with or without plasma, whereas, thrombin was rapidly inactivated by heparin in the presence of plasma. In conclusion, we have developed a rapid and reproducible procedure for isolation in high yield of large quantities of the thrombin-like enzyme from the venom of the eastern diamondback rattlesnake. Studies are continuing on the primary structure and possible clinical applications of this enzyme.


1993 ◽  
Vol 71 (1-2) ◽  
pp. 22-26 ◽  
Author(s):  
Pratima Dutta ◽  
Gopal C. Majumder

A neutral β-D-galactosidase has been partially purified from rat epididymis and characterized. The enzyme having molecular mass of approximately 50 kilodaltons has been purified 400-fold by using calcium phosphate gel adsorption, DEAE-cellulose chromatography, Sephadex G-100 gel filtration, and concanavalin A - agarose affinity chromatography. Although the neutral enzyme binds to the concanavalin A affinity column, the activity could be eluted with α-methyl mannoside only if the buffer contained salt (NaCl) at a concentration as high as 0.3 M. The enzyme was of cytosolic origin, since 90% of the total enzymic activity of the tissue homogenate was recovered in the soluble fraction of these cells. The neutral β-galactosidase was not dependent on metal ions for its activity and it had a pH optimum of 7.0. Zn2+, p-chloromercuribenzoate, Hg2+, and Pb2+ served as potent inhibitors of the enzyme. There was a marked increase (approximately fourfold) in the specific activity of the neutral β-galactosidase during sexual maturity of epididymis in vivo.Key words: neutral β-galactosidase, rat epididymal, cytosolic, developmental, sexual maturity.


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