scholarly journals Panagrellus redivivus ornithine decarboxylase: structure of the gene, expression in Escherichia coli and characterization of the recombinant protein

1996 ◽  
Vol 317 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Gabriele NIEMANN ◽  
Hans von BESSER ◽  
Rolf D. WALTER

A Southern blot analysis of the Panagrellus redivivus ornithine decarboxylase (ODC) gene suggests that it is a single-copy gene that resides on a genomic 3.2 kb EcoRI fragment. Phage clones possessing ODC gene sequences were isolated from a genomic EMBL-4 library and purified. The phage DNA inserts were analysed and a 3.2 kb EcoRI fragment containing the entire ODC gene was isolated. The nucleotide sequence analysis of this fragment reveals that the gene is interrupted by two introns of 47 and 49 bp. In the 5´ non-translated region of the gene, putative AP1, VPE2 and c-Myc binding sites were identified. The ODC cDNA was expressed in a bacterial system as a His-fusion protein and the enzyme was purified by Ni2+-chelating affinity chromatography. The subunit molecular mass, as deduced from the cDNA and shown by SDS/PAGE, is 47.1 kDa. On the basis of gel filtration analyses it is shown that the active enzyme is a dimer. The specific enzyme activity was determined to be 4.2 μmol CO2/min/mg protein. The enzyme is dependent on pyridoxal 5-phosphate as a cofactor, and the presence of dithioerythritol or other thiol-reducing agents is essential for maximal activity. The Km value for l-ornithine was determined as 44 μM. The Ki values for putrescine, α-difluoromethylornithine, α-hydrazino-ornithine and α-methylornithine were calculated as 51, 34, 0.34 and 42 μM respectively.

2005 ◽  
Vol 387 (1) ◽  
pp. 271-280 ◽  
Author(s):  
Seonghun KIM ◽  
Sun Bok LEE

The extremely thermoacidophilic archaeon Sulfolobus solfataricus utilizes D-glucose as a sole carbon and energy source through the non-phosphorylated Entner–Doudoroff pathway. It has been suggested that this micro-organism metabolizes D-gluconate, the oxidized form of D-glucose, to pyruvate and D-glyceraldehyde by using two unique enzymes, D-gluconate dehydratase and 2-keto-3-deoxy-D-gluconate aldolase. In the present study, we report the purification and characterization of D-gluconate dehydratase from S. solfataricus, which catalyses the conversion of D-gluconate into 2-keto-3-deoxy-D-gluconate. D-Gluconate dehydratase was purified 400-fold from extracts of S. solfataricus by ammonium sulphate fractionation and chromatography on DEAE-Sepharose, Q-Sepharose, phenyl-Sepharose and Mono Q. The native protein showed a molecular mass of 350 kDa by gel filtration, whereas SDS/PAGE analysis provided a molecular mass of 44 kDa, indicating that D-gluconate dehydratase is an octameric protein. The enzyme showed maximal activity at temperatures between 80 and 90 °C and pH values between 6.5 and 7.5, and a half-life of 40 min at 100 °C. Bivalent metal ions such as Co2+, Mg2+, Mn2+ and Ni2+ activated, whereas EDTA inhibited the enzyme. A metal analysis of the purified protein revealed the presence of one Co2+ ion per enzyme monomer. Of the 22 aldonic acids tested, only D-gluconate served as a substrate, with Km=0.45 mM and Vmax=0.15 unit/mg of enzyme. From N-terminal sequences of the purified enzyme, it was found that the gene product of SSO3198 in the S. solfataricus genome database corresponded to D-gluconate dehydratase (gnaD). We also found that the D-gluconate dehydratase of S. solfataricus is a phosphoprotein and that its catalytic activity is regulated by a phosphorylation–dephosphorylation mechanism. This is the first report on biochemical and genetic characterization of D-gluconate dehydratase involved in the non-phosphorylated Entner–Doudoroff pathway.


1993 ◽  
Vol 293 (2) ◽  
pp. 487-493 ◽  
Author(s):  
N Yarlett ◽  
B Goldberg ◽  
M A Moharrami ◽  
C J Bacchi

Ornithine decarboxylase (ODC), the lead enzyme in polyamine biosynthesis, was partially purified from Trichomonas vaginalis and its kinetic properties were studied. The enzyme appears to be of special significance in this anaerobic parasite, since the arginine dihydrolase pathway generates ATP as well as putrescine from arginine. ODC from T. vaginalis had a broad substrate specificity, decarboxylating ornithine (100%), lysine (1.0%) and arginine (0.1%). The enzyme had a pH optimum of 6.5, a temperature optimum of 37 degrees C and was pyridoxal 5′-phosphate-dependent. Attempts to separate ornithine- from lysine-decarboxylating activity by thermal-stability and pH-optima curves were not successful. Although Km values for ornithine and lysine were 109 and 91 microM respectively, and the Vmax values for these substrates were 1282 and 13 nmol/min per mg of protein respectively, the most important intracellular substrate is ornithine, since intracellular ornithine levels are 3.5 times those of lysine and extracellular putrescine levels are 7.5 times those of cadaverine. Ornithine was also an effective inhibitor of lysine-decarboxylating activity (Ki 150 microM), whereas lysine was relatively ineffective as inhibitor of ornithine-decarboxylating activity (Ki 14.5 mM). Crude ODC activity was localized (86%) in the 43,000 g supernatant and 3303-fold purification was obtained by (NH4)2SO4 salting and DEAE-Sephacel, agarose-gel and hydroxyapatite chromatography steps. The enzyme bound difluoro[3H]methylornithine ([3H]DFMO) with a ratio of drug bound to activity of 2500 fmol/unit, where 1 unit corresponds to 1 nmol of CO2 released from ornithine/min. The enzyme had a native M(r) of 210000 (gel filtration), with a subunit M(r) of 55,000 (by SDS/PAGE), suggesting that the trichomonad enzyme is a tetramer. From the subunit M(r) and binding ratio of DFMO, there is about 137 ng of ODC per mg of T. vaginalis protein (0.013%). The significant amount of ODC protein present supports the view that putrescine synthesis in T. vaginalis plays an important role in the metabolism of the parasite.


2012 ◽  
Vol 550-553 ◽  
pp. 1496-1502
Author(s):  
Hong Ju Jiang ◽  
Wei Zhen Xu ◽  
Jia Mei Song ◽  
Dong Ping Sun

Two extracellular alkaline polygalacturonases from extracts of liquid cultures of Paenibacillus polymyxa 20185 were purified by gel filtration chromatography to homogeneity as judged by SDS-PAGE. The purified alkaline polygalacturonases (PG1 and PG2) had a similar molecular weight of 65 kDa, exhibited maximal activity at 50°C with pH 10.0, and were stable in alkaline conditions. The purified alkaline polygalacturonases activities were enhanced in the presence of Mg2+, and were resistant to inhibition by Mn2+, Zn2+and Cu2+. Michaelis-menten constants of PG1 and PG2 were found as 3.6mg/mL and 3.5mg/mL, respectively.


2016 ◽  
Vol 13 (2) ◽  
pp. 392-398
Author(s):  
Baghdad Science Journal

Catalase (EC 1.11.1.6) is a well known enzyme which exists in almost all living creatures exposing to oxygen (such as plants, bacteria, and animals). It is a very necessary enzyme to protect the cell from oxidative detriment by reactive oxygen species (ROS). The aim of this study is the partial purification and characterization of Catalase enzyme from Banana peels. In this study, fresh banana peels are treated with 70 % ethanol ,further separated with chloroform ,water and ethyl acetate respectively .The supernatant of the enzymatic sample which is treated with chloroform is loaded into gel filtration column with Sephadex G-100 (1.0 x 90 cm) equilibrated with pH7 buffer media (phosphate buffer 0.1 M). Kinetic studies of the purified enzyme activity are measured and characterized .The maximal activity (26.04 units/mg) of catalase is observed with chloroform buffer extraction. The kinetics of catalase; Michalis constant Km and maximum velocity Vmax is determined using Linweaver- Burk plot, The Km value for catalase (434.7mM), Vmax (100 m mole min -1). Characterization results demonstrate that the optimal pH for activity is (7.6). And the optimal temperature for activity is 30?C .The present study indicates that Banana peels is a good source of catalase enzyme.


2016 ◽  
Vol 88 (suppl 1) ◽  
pp. 479-487 ◽  
Author(s):  
YUPING MA ◽  
SIWEN SUN ◽  
HUI HAO ◽  
CHUNPING XU

ABSTRACT A soil isolate, Penicillium janthinellum sw09 has been found to produce significant amounts of an extracellular pectinase subsequently characterized as exo-polygalacturonase (exo-PG). By optimizing growth conditions, P. janthinellum sw09 produced high amount of exo-PG (16.54 units/mL). The crude enzyme was purified by gel filtration chromatography and two exo-PG activity peaks (designated as PGI and PGII) were revealed. On SDS-PAGE analysis, purified PGII using DEAE-Sepharose FF column, was found to be a single band with a molecular mass of 66.2 kDa. The purified PGII exhibited maximal activity at the temperature of 45 oC and pH 5.0. The stability profiles show that PGII is more stable in the pH range of 4.0-8.0 and below 60 oC. The Km and Vmax for the enzyme was 1.74 mg/mL and 18.08 μmol/ (mL•min), respectively. Due to this enzymatic characterization, this pectinase is an attractive candidate for applications in degradation of pectin.


2011 ◽  
Vol 74 (8) ◽  
pp. 1309-1314 ◽  
Author(s):  
MARYSE BONNIN-JUSSERAND ◽  
COSETTE GRANDVALET ◽  
VANESSA DAVID ◽  
HERVÉ ALEXANDRE

Ornithine decarboxylase (ODC) is responsible for the production of putrescine, the major biogenic amine found in wine. Oenococcus oeni is the most important lactic acid bacterium in the winemaking process and is involved in malolactic fermentation. We report here the characterization of ODC from an O. oeni strain isolated from wine. Screening of 263 strains isolated from wine and cider from all over the world revealed that the presence of the odc gene appears to be strain specific in O. oeni. After cloning, heterologous expression in Escherichia coli, and characterization, the enzyme was found to have a molecular mass of 85 kDa and a pI of 6.2 and revealed maximal activity at pH 5.5 and an optimum temperature of 35°C. Kinetic studies showed that O. oeni ODC is specific for l-ornithine with a Km value of 1 mM and a Vmax of 0.57 U·mg−1. The hypothesis that cadaverine, which results from lysine decarboxylation, may be linked to putrescine production is not valid since O. oeni ODC cannot decarboxylate L-lysine. As no lysine decarboxylase was detected in any of the O. oeni genomes sequenced, cadaverine synthesis may result from another metabolic pathway. This work is the first characterization of an ODC from a lactic acid bacterium isolated from a fermented product.


2014 ◽  
Vol 6 (2) ◽  
pp. 49-57 ◽  
Author(s):  
L Bari ◽  
P Hassan ◽  
N Absar ◽  
S Khatun ◽  
MI Hossain

Peroxidase enzyme was isolated and purified from the pulp of disease infected ripen papaya of local variety by 90% ammonium sulphate precipitation, chromatography on DEAEcellulose followed by hydrophobic chromatography on Phenyl Sepharose CL-4B and the purifications achieved was about 7.2 fold with 2.5% recovery. The purified enzyme was homogeneous as judged by polyacrylamide slab gel electrophoresis. The purified enzyme had a Mr of about 55,000 and 50 000 as determined by gel filtration on Sephadex G-100 and SDS-PAGE, respectively. The molecular mass of the enzyme was found to be very similar under both reducing and non-reducing conditions indicating that the enzyme contains no subunit. The enzyme has the following characteristics: pH optima at 6.0, temperature optima around 38°C, enzyme activity was found to be strongly inhibited in the presence of potassium cyanide and Fe+2 while the activity was found to be remarkably increased in the presence of ammonium sulphate. The Km value for the peroxidase obtained with pyrogallol as substrate was 0.027 mM. DOI: http://dx.doi.org/10.3329/bjmb.v6i2.17643 Bangladesh J Med Biochem 2013; 6(2): 49-57


2000 ◽  
Vol 66 (1) ◽  
pp. 252-256 ◽  
Author(s):  
Katsuichi Saito ◽  
Kazuya Kondo ◽  
Ichiro Kojima ◽  
Atsushi Yokota ◽  
Fusao Tomita

ABSTRACT Streptomyces exfoliatus F3-2 produced an extracellular enzyme that converted levan, a β-2,6-linked fructan, into levanbiose. The enzyme was purified 50-fold from culture supernatant to give a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weights of this enzyme were 54,000 by SDS-PAGE and 60,000 by gel filtration, suggesting the monomeric structure of the enzyme. The isoelectric point of the enzyme was determined to be 4.7. The optimal pH and temperature of the enzyme for levan degradation were pH 5.5 and 60°C, respectively. The enzyme was stable in the pH range 3.5 to 8.0 and also up to 50°C. The enzyme gave levanbiose as a major degradation product from levan in an exo-acting manner. It was also found that this enzyme catalyzed hydrolysis of such fructooligosaccharides as 1-kestose, nystose, and 1-fructosylnystose by liberating fructose. Thus, this enzyme appeared to hydrolyze not only β-2,6-linkage of levan, but also β-2,1-linkage of fructooligosaccharides. From these data, the enzyme from S. exfoliatus F3-2 was identified as a novel 2,6-β-d-fructan 6-levanbiohydrolase (EC 3.2.1.64 ).


2011 ◽  
Vol 63 (3) ◽  
pp. 747-756 ◽  
Author(s):  
A.K.M. Asaduzzaman ◽  
Habibur Rahman ◽  
Tanzima Yeasmin

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.


2014 ◽  
Vol 28 ◽  
pp. 10-16 ◽  
Author(s):  
R. Sadeesh Kumar ◽  
R. Rajesh ◽  
S. Gokulakrishnan ◽  
J. Subramanian

Regulation and production of Fibrinolytic enzymes from bacterial sources especially from Bacillus strains has taken a leading role in the medical sciences for the treatment of cardiovascular disorders as it removes thrombus or clots adding to its significant role in curing human health issues saving millions. Significant progress has been made during the last few years on the studies of fibrinolytic enzymes in identifying, cloning, purification, characterization and overproduction of these for commercialization in medical sciences and in fields like detergents development. Production of fibrinolytic enzyme from Bacillus circulans was done using Nutrient broth medium. In addition, a strong fibrinolytic enzyme was purified from the cultivation media. The purified enzyme was almost homogeneous with other species of same genus, as examined by SDS−PAGE and sephadex G-75 column chromatography. The enzyme had an optimal pH of 7-12, an optimal temperature of 50 °C, for fibrin hydrolysis. The molecular mass estimated by gel filtration was 24 to36 KDa. Further studies for characterization and structural elucidation are necessary for their medicinal applications and molecular biological characteristics.


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