scholarly journals Purification and characterization of a novel phosphoenolpyruvate carboxylase from banana fruit

1995 ◽  
Vol 307 (3) ◽  
pp. 807-816 ◽  
Author(s):  
R D Law ◽  
W C Plaxton
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Specific Activity ◽  
Immune Serum ◽  
Enzymic Activity ◽  
Banana Fruit ◽  
Native Molecular Mass ◽  
Apparent Homogeneity ◽  
Sds Page ◽  
Cnbr Cleavage

Phosphoenolpyruvate carboxylase (PEPC) from ripened banana (Musa cavendishii L.) fruits has been purified 127-fold to apparent homogeneity and a final specific activity of 32 mumol of oxaloacetate produced/min per mg of protein. Non-denaturing PAGE of the final preparation resolved a single protein-staining band that co-migrated with PEPC activity. Polypeptides of 103 (alpha-subunit) and 100 (beta-subunit) kDa, which stain for protein with equal intensity and cross-react strongly with anti-(maize leaf PEPC) immune serum, were observed following SDS/PAGE of the final preparation. CNBr cleavage patterns of the two subunits were similar, but not identical, suggesting that these polypeptides are related, but distinct, proteins. The enzyme's native molecular mass was estimated to be about 425 kDa. These data indicate that in contrast to the homotetrameric PEPC from most other sources, the banana fruit enzyme exists as an alpha 2 beta 2 heterotetramer. Monospecific rabbit anti-(banana PEPC) immune serum effectively immunoprecipitated the activity of the purified enzyme. Immunoblotting studies established that the 100 kDa subunit did not arise via proteolysis of the 103 kDa subunit after tissue extraction, and that the subunit composition of banana PEPC remains uniform throughout the ripening process. PEPC displayed a typical pH activity profile with an alkaline optimum and activity rapidly decreasing below pH 7.0. Enzymic activity was absolutely dependent on the presence of a bivalent metal cation, with Mg2+ or Mn2+ fulfilling this requirement. The response of the PEPC activity to PEP concentration and to various effectors was greatly influenced by pH and glycerol addition to the assay. The enzyme was activated by hexose-monophosphates and potently inhibited by malate, succinate, aspartate and glutamate at pH 7.0, whereas the effect of these metabolites was considerably diminished or completely abolished at pH 8.0. The significance of metabolite regulation of PEPC is discussed in relation to possible functions of this enzyme in banana fruit metabolism.

scholarly journals Purification and characterization of cytosolic pyruvate kinase from banana fruit

2000 ◽  
Vol 352 (3) ◽  
pp. 875-882 ◽  
Author(s):  
William L. TURNER ◽  
William C. PLAXTON
Keyword(s):  
Pyruvate Kinase ◽  
Specific Activity ◽  
Gel Filtration ◽  
Banana Fruit ◽  
Ph Optimum ◽  
Cytosolic Ph ◽  
Pep Carboxylase ◽  
Sds Page ◽  
Optimal Efficiency

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.

scholarly journals Purification and characterization of casein kinase I from broccoli

1993 ◽  
Vol 293 (1) ◽  
pp. 283-288 ◽  
Author(s):  
L J Klimczak ◽  
A R Cashmore
Keyword(s):  
Molecular Mass ◽  
Specific Activity ◽  
Gel Filtration ◽  
Cross Reactivity ◽  
Casein Kinase ◽  
Casein Kinase I ◽  
Native Molecular Mass ◽  
Specificity And Sensitivity ◽  
Sds Page

Casein kinase I from broccoli was purified approximately 65,000-fold by chromatography on phosphocellulose, phenyl-Sepharose, CM-Sephacel, and affinity chromatography on N-(2-aminoethyl)-5-chloroisoquinolone-8-sulphonamide (CKI-7)-Sepharose. The catalytic subunit of casein kinase I was identified as a 36-38 kDa polypeptide doublet by using the technique of activity gel assay after SDS/PAGE with casein as a gel-incorporated substrate. A silver-stained polypeptide doublet of the same molecular mass constituted at least 95% of the protein in the final preparation, corresponding to a specific activity of approximately 1800 nmol/min per mg of protein. The enzyme was found to be a monomer by gel filtration and glycerol gradient sedimentation; the native molecular mass was calculated to be 34.2 kDa. These characteristics, as well as other essential features of plant casein kinase I activity, such as substrate specificity and sensitivity to inhibitors, were found to be similar to those established for animal casein kinase I. Broccoli casein kinase I showed weak immunological cross-reactivity with antibodies raised against bovine casein kinase I.

scholarly journals Purification and Characterization of a Polyextremophilicα-Amylase from an Obligate HalophilicAspergillus penicillioidesIsolate and Its Potential for Souse with Detergents

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Imran Ali ◽  
Ali Akbar ◽  
Mohammad Anwar ◽  
Sehanat Prasongsuk ◽  
Pongtharin Lotrakul ◽  
...  
Keyword(s):  
Specific Activity ◽  
Amylase Activity ◽  
Gel Filtration ◽  
Soluble Starch ◽  
Ammonium Sulfate Precipitation ◽  
Purification And Characterization ◽  
Apparent Homogeneity ◽  
Sds Page ◽  
Good Potential

An extracellularα-amylase from the obligate halophilicAspergillus penicillioidesTISTR3639 strain was produced and enriched to apparent homogeneity by ammonium sulfate precipitation and Sephadex G100 gel filtration column chromatography. The mass of the purified amylase was estimated to be 42 kDa by SDS-PAGE. With soluble starch as the substrate it had a specific activity of 118.42 U·mg−1andVmax⁡andKmvalues of 1.05 µmol·min−1·mg−1and 5.41 mg·mL−1, respectively. The enzyme was found to have certain polyextremophilic characteristics, with an optimum activity at pH 9, 80°C, and 300 g·L−1NaCl. The addition of CaCl2at 2 mM was found to slightly enhance the amylase activity, while ZnCl2, FeCl2, or EDTA at 2 mM was strongly or moderately inhibitory, respectively, suggesting the requirement for a (non-Fe2+or Zn2+) divalent cation. The enzyme retained more than 80% of its activity when incubated with three different laundry detergents and had a better performance compared to a commercial amylase and three detergents in the presence of increasing NaCl concentrations up to 300 g·L−1. Accordingly, it has a good potential for use as anα-amylase in a low water activity (high salt concentration) and at high pH and temperatures.

scholarly journals Overproduction, purification and characterization of M.EcoHK31I, a bacterial methyltransferase with two polypeptides

1996 ◽  
Vol 314 (1) ◽  
pp. 321-326 ◽  
Author(s):  
Kai-Fai LEE ◽  
Yen-Chywan LIAW ◽  
Pang-Chui SHAW
Keyword(s):  
Initial Rate ◽  
Specific Activity ◽  
Overlapping Genes ◽  
Purification And Characterization ◽  
Native Molecular Mass ◽  
Apparent Homogeneity ◽  
Molecular Masses ◽  
Chromatographic Media ◽  
Lambda Dna

The two overlapping genes coding for EcoHK31I methyltransferase have previously been cloned, sequenced and expressed [Lee, Kam and Shaw (1995) Nucleic Acids Res. 23, 103–108]. Here we describe protocols developed to purify polypeptides α and β together or separately, to apparent homogeneity by various chromatographic media. M.EcoHK31I is a heterodimer with a native molecular mass of 61 kDa. Its specific activity towards non-methylated lambda DNA was 3.0×105 units per mg of protein. The respective denatured molecular masses of polypeptides α and β were 38 and 23 kDa, and their pI values were 8.7 and 6.8. Initial rate kinetic parameters of the native enzyme were 2.0 nM, 0.58 μM and 3 min-1 for KmDNA, KmAdoMet and kcat. respectively, where AdoMet stands for S-adenosyl-L-methionine. Fully active enzyme was reconstituted by co-purifying the two separately synthesized polypeptides, and activity assays confirmed our previous finding that two polypeptides were needed to methylate substrate DNA.

METABOLISM OF PROGESTERONE BY THE RAT OVARY: FORMATION OF 3β-HYDROXY-5α-PREGNAN-20-ONE BY OVARIAN MICROSOMES

1969 ◽  
Vol 61 (4) ◽  
pp. 618-628 ◽  
Author(s):  
A. Zmigrod ◽  
H. R. Lindner
Keyword(s):  
Oxidation Product ◽  
Microsomal Fraction ◽  
Biological Function ◽  
Specific Activity ◽  
Metabolite Identification ◽  
Enzymic Activity ◽  
Chromatographic Behaviour ◽  
Rat Ovary ◽  
Chromatographic Characterization

ABSTRACT A microsomal fraction from rat ovaries incubated with [4-14C] progesterone in the presence of NADPH produced radioactive 3β-hydroxy-5α-pregnan-20-one as the major metabolite. Identification of this compound, not hitherto isolated from mammalian ovaries, was based on (i) paper and gas-chromatographic behaviour of the free compound and its acetate, (ii) gas-chromatographic characterization of the thioketal derivative and the oxidation product, and (iii) recrystallization with authentic carrier to constant specific activity. Ovaries from both pregnant and prooestrous rats showed this enzymic activity. The possible biological function of ovarian steroid reductases is discussed.

scholarly journals Purificación Parcial y Caracterización de Alfa Amilasa de granos germinados de Chenopodium quinoa (Quinua)

2018 ◽  
pp. 52-58
Keyword(s):  
Specific Activity ◽  
Chenopodium Quinoa ◽  
Maximum Activity ◽  
Alpha Amylase ◽  
Partial Purification ◽  
Chemical Hydrolysis ◽  
Germination Process ◽  
Sds Page ◽  
Global Population

Purificación Parcial y Caracterización de Alfa Amilasa de granos germinados de Chenopodium quinoa (Quinua) Partial Purification and Characterization of Alpha Amylase from germinated grains from Chenopopdium quinoa (Quinua) Melissa Bedón Gómez, Oscar Nolasco Cárdenas, Carlos Santa Cruz C. y Ana I. F. Gutiérrez Román Universidad Nacional Federico Villarreal, Facultad de Ciencias Naturales y Matemática, Laboratorio de Bioquímica y Biología Molecular, Jr. Río Chepén S/N, El Agustino. Telefax: 362 - 3388 DOI: https://doi.org/10.33017/RevECIPeru2013.0007/ Resumen Las alfa amilasas son las enzimas más estudiadas e importantes en el campo biotecnológico e industrial; ya que han reemplazado por completo la hidrólisis química del almidón. Estas enzimas son imprescindibles en la elaboración de productos alimenticios, combustibles, medicamentos y detergentes con la finalidad de optimizar procesos y conservar el medio ambiente. La α-amilasa puede ser purificada de diferentes organismos como plantas, animales, hongos y bacterias; actualmente un gran número de α-amilasas bacterianas en especial del género Bacillus están disponibles comercialmente y son las más utilizadas en las industrias. Sin embargo, la producción de éstas no satisfacen los requerimientos industriales en el mundo; ya que, la demanda de esta enzima se ha incrementado en los últimos dos años y el empleo de α-amilasas bacterianas ha provocado alergias afectando al 15% de la población a nivel mundial. . En este estudio, como fuente de α-amilasa se emplearon semillas de Chenopodium quinoa (quinua) var hualhuas blanca durante el proceso de germinación; esta enzima fue parcialmente purificada por precipitación con sulfato de amonio obteniendo una actividad específica final de 35.60U/mg y un grado de purificación de 5 veces. La purificación fue confirmada por SDS-PAGE, encontrando un peso molecular de 44kDa. La actividad enzimática se evaluó mediante el método de Miller mostrando máxima actividad a pH 7 y a temperatura de 37ºC. La linealización de Lineweaver-Burk nos dio un Km de 16mg/mL y Vmax de 100µM de maltosa/min. Por lo tanto, esta caracterización reúne los pre-requisitos necesarios para la aplicación en la industria. Descriptores: Chenopodium quinoa, alfa amilasa, germinación, purificación parcial. Abstract The alpha amylases are the enzymes most studied and important in biotechnology and industry; because they have completely replaced the starch’s chemical hydrolysis. These enzymes are essential in the food production, medicines and detergents in order to optimize processes and conserve the environment. The α-amylase can be isolated from different organisms such as plants, animals, fungi and bacteria, now a large number of bacterial α-amylases especially from genus Bacillus are commercially available and they are the most used in industry. However, the production of these do not meet industry requirements in the world, because the demand for this enzyme has increased in the last two years and the use of bacterial α-amilase has caused allergies affecting the 15% of the global population. In this study, as a source of α-amylase used the seeds from Chenopodium quinoa (quinoa). Var. white hualhuas during the germination process, this enzyme was partially purified by ammonium sulfate precipitation to obtain a final specific activity of 35.60U/mg, and a grade of purification of 5 times. The purification was confirmed by SDS-PAGE, where the molecular weight was 44kDa. The enzyme activity was evaluated by Miller method showing maximum activity at pH 7 and 37ºC. The Lineweaver-Burk linearization shows a Km of 16mg/mL and Vmax of 100μM the maltose / min. Therefore, these characterizations meet the prerequisites need for industry. Keywords: Chenopodium quinoa; alpha amylase; germination; partial purification

scholarly journals PURIFICATION AND PARTIAL CHARACTERIZATION OF L-ASPARAGINASE ENZYME PRODUCED BY NEWLY ISOLATE BACILLUS SP.

2017 ◽  
Vol 18 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Dzun Noraini Jimat ◽  
Intan Baizura Firda Mohamed ◽  
Azlin Suhaida Azmi ◽  
Parveen Jamal
Keyword(s):  
Specific Activity ◽  
Hot Spring ◽  
Gel Filtration ◽  
Maximum Activity ◽  
Exchange Chromatography ◽  
Bacillus Sp ◽  
Sds Page ◽  
Fast Flow ◽  
Microbial Strain

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.

scholarly journals Purification and characterization of a thermostable ADP-glucose pyrophosphorylase from Thermus caldophilus GK-24

1996 ◽  
Vol 319 (3) ◽  
pp. 977-983 ◽  
Author(s):  
Jeong Heon KO ◽  
Cheorl Ho KIM ◽  
Dae-Sil LEE ◽  
Yu Sam KIM
Keyword(s):  
Molecular Mass ◽  
Specific Activity ◽  
Gel Filtration ◽  
Higher Plant ◽  
Sds Page ◽  
Thermus Caldophilus ◽  
Internal Peptide ◽  
Adp Glucose Pyrophosphorylase ◽  
Fructose 1,6 Bisphosphate

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.

scholarly journals Characterization of a Robust and pH-Stable Tannase from Mangrove-Derived Yeast Rhodosporidium diobovatum Q95

Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 546
Author(s):  
Jie Pan ◽  
Ni-Na Wang ◽  
Xue-Jing Yin ◽  
Xiao-Ling Liang ◽  
Zhi-Peng Wang
Keyword(s):  
Gallic Acid ◽  
Tannic Acid ◽  
Specific Activity ◽  
Maximum Activity ◽  
Sds Page ◽  
Rhodosporidium Diobovatum ◽  
Bacteria And Fungi ◽  
Ph Range ◽  
First Time

Tannase plays a crucial role in many fields, such as the pharmaceutical industry, beverage processing, and brewing. Although many tannases derived from bacteria and fungi have been thoroughly studied, those with good pH stabilities are still less reported. In this work, a mangrove-derived yeast strain Rhodosporidium diobovatum Q95, capable of efficiently degrading tannin, was screened to induce tannase, which exhibited an activity of up to 26.4 U/mL after 48 h cultivation in the presence of 15 g/L tannic acid. The tannase coding gene TANRD was cloned and expressed in Yarrowia lipolytica. The activity of recombinant tannase (named TanRd) was as high as 27.3 U/mL. TanRd was purified by chromatography and analysed by SDS-PAGE, showing a molecular weight of 75.1 kDa. The specific activity of TanRd towards tannic acid was 676.4 U/mg. Its highest activity was obtained at 40 °C, with more than 70% of the activity observed at 25–60 °C. Furthermore, it possessed at least 60% of the activity in a broad pH range of 2.5–6.5. Notably, TanRd was excellently stable at a pH range from 3.0 to 8.0; over 65% of its maximum activity remained after incubation. Besides, the broad substrate specificity of TanRd to esters of gallic acid has attracted wide attention. In view of the above, tannase resources were developed from mangrove-derived yeasts for the first time in this study. This tannase can become a promising material in tannin biodegradation and gallic acid production.

scholarly journals Purification and Partial Characterization of β-Glucosidase from Fresh Leaves of Tea Plants (Camellia sinensis (L.) O. Kuntze)

2005 ◽  
Vol 37 (6) ◽  
pp. 363-370 ◽  
Author(s):  
Ye-Yun Li ◽  
Chang-Jun Jiang ◽  
Xiao-Chun Wan ◽  
Zheng-Zhu Zhang ◽  
Da-Xiang Li
Keyword(s):  
Specific Activity ◽  
Gel Filtration ◽  
Maximum Activity ◽  
Exchange Chromatography ◽  
Optimum Activity ◽  
Development Of Resistance ◽  
Sds Page ◽  
C 50 ◽  
Tea Plants

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.

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