scholarly journals Easy and Rapid Purification of Highly Active Nisin

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
André Abts ◽  
Antonino Mavaro ◽  
Jan Stindt ◽  
Patrick J. Bakkes ◽  
Sabine Metzger ◽  
...  
Keyword(s):  
Low Ph ◽  
Exchange Chromatography ◽  
Single Step ◽  
Cation Exchange Chromatography ◽  
Gram Positive Bacteria ◽  
Highly Active ◽  
One Step ◽  
Rapid Purification ◽  
The One ◽  
Purification Protocol

Nisin is an antimicrobial peptide produced and secreted by several L. lactis strains and is specifically active against Gram-positive bacteria. In previous studies, nisin was purified via cation exchange chromatography at low pH employing a single-step elution using 1 M NaCl. Here, we describe an optimized purification protocol using a five-step NaCl elution to remove contaminants. The obtained nisin is devoid of impurities and shows high bactericidal activity against the nisin-sensitive L. lactis strain NZ9000. Purified nisin exhibits an IC50 of ~3 nM, which is a tenfold improvement as compared to nisin obtained via the one-step elution procedure.

A modified fractionation procedure for avian erythrocyte histones

1969 ◽  
Vol 47 (12) ◽  
pp. 1121-1123 ◽  
Author(s):  
G. H. M. Adams ◽  
J. M. Neelin
Keyword(s):  
Cation Exchange ◽  
Exchange Chromatography ◽  
Cation Exchange Chromatography ◽  
Fractionation Procedure ◽  
Exclusion Chromatography ◽  
One Step ◽  
Avian Erythrocyte ◽  
Fractionation Method ◽  
Time Required

The fractionation method of Vidali and Neelin for avian erythrocyte histones was modified to reduce the time required to obtain clean fractions of serine-rich and arginine-rich histones. Histones were extracted from washed nuclei in one step with 0.20 M HCl. The lysine-rich and the moderately lysine-rich histones were fractionated by cation-exchange chromatography but the serine-rich and arginine-rich histones were eluted together. These histones were separated by subsequent exclusion chromatography.

On the Occurrence and Structure of Subunits of Endopolygalacturonase Isoforms in Mature-Green and Ripening Tomato Fruits

1991 ◽  
Vol 18 (1) ◽  
pp. 65 ◽  
Author(s):  
BJ Pogson ◽  
CJ Brady ◽  
GR Orr
Keyword(s):  
Tomato Fruit ◽  
Exchange Chromatography ◽  
Molecular Forms ◽  
Cation Exchange Chromatography ◽  
Ripe Fruit ◽  
Tomato Fruits ◽  
Green Fruit ◽  
C Terminus ◽  
The One ◽  
Polygalacturonase Activity

Endopolygalacturonase [poly(1,4-α-galacturonide) glycanohydrolase EC 3.2.1.151 occurs in tomato fruit in three molecular forms- PG1, PG2A, PG2B. Trace amounts of PG1, 1-10 pkat g-1 are shown to occur in mature-green fruit as compared to 17 nkat in ripe fruit. As polygalacturonase activity increases through ripening, the percentage of the activity due to PG1 decreases progressively from 100 to less than 20. On fully or partly demethylated substrates, PG1 is more active than PG2 when the ionic strength is that expected in the tissue apoplast. A method for purifying PGI from ripe fruit is described. PG1 preparations contain polypeptides of Mr 45, 43 and 38 thousand. The Mr 43 thousand and 45 thousand components correspond in size to PG2A and PG2B and are detected by antisera raised against PG2A. The M, 38 thousand polypeptide is immunologically distinct. From carbohydrate and amino acid analyses, this polypeptide appears to contain 2870 carbohydrate as glucosamine, mannose, xylose and fucose attached to a polypeptide of estimated Mr 28 342 that is rich in tyrosine and glycine. A method for purifying the subunits of PG1 by cation exchange chromatography in 6 M urea is described. PG2A and PG2B were separated by column chromatography and shown to have identical N-terminal sequences, and serine at the C-terminus. PG2A and PG2B are confirmed as two glycoforms of the one polypeptide. The possibility that PGl consists of populations of molecules containing either PG2A or PG2B coupled with the Mr 38 thousand polypeptide is discussed.

scholarly journals Improving the Activity of Fe/C/N ORR Electrocatalyst Using Double Ammonia Promoted CO2 Laser Pyrolysis

2020 ◽  
Vol 6 (4) ◽  
pp. 63
Author(s):  
Henri Perez ◽  
Mathieu Frégnaux ◽  
Emeline Charon ◽  
Arnaud Etcheberry ◽  
Olivier Sublemontier
Keyword(s):  
Co2 Laser ◽  
Large Scale ◽  
Laser Energy ◽  
Reduction Reaction ◽  
Laser Pyrolysis ◽  
Highly Active ◽  
One Step ◽  
Orr Activity ◽  
Set Up ◽  
The One

Recently, we reported the use of CO2 laser pyrolysis for the synthesis of promising Fe/C/N electrocatalysts for Oxygen Reduction Reaction (ORR) in fuel cells. The set-up used single laser pyrolysis of an aerosolized solution of iron acetylacetonate in toluene with ammonia, both as laser energy transfer agent and nitrogen source. In the present paper, we investigate the effect of a second ammonia promoted CO2 laser pyrolysis on the feature and ORR activity of Fe/C/N electrocatalysts. Indeed, compared to single pyrolysis, the second ammonia promoted CO2 laser pyrolysis could be an interesting way to synthesize in one-step performing ORR electrocatalysts on a large scale. For this comparison, a two-stage reactor was built, allowing both single ammonia-induced CO2 laser pyrolysis as reported previously or double ammonia-induced CO2 laser pyrolysis. In the latter configuration, the catalyst nanopowder flow is formed at the first stage of the reactor, then mixed with a second ammonia flow and allowed to cross a second CO2 laser beam, thus undergoing a second ammonia-induced CO2 laser pyrolysis before being collected on filters. It is found that the second ammonia-induced CO2 laser pyrolysis significantly improves the ORR performances of the materials prepared by single CO2 laser pyrolysis. The effect is demonstrated for three different catalysts for which the onset potentials for the ORR from single-stage to double-stage configuration increase from 625 mV to 845 mV, 790 mV to 860 mV, and 800 mV to 885 mV, respectively. The selectivity of the ORR was determined at 600 mV/SHE and lie between 3.41 and 3.72. These promising performances suggesting potentialities for the one-step formation of highly active Fe/C/N ORR electrocatalysts are discussed, based on results of surface analysis by XPS, specific surface area measurements, and Raman spectroscopy.

scholarly journals Characterization of highly active 2-keto-3-deoxy-L-arabinonate and 2-keto-3-deoxy-D-xylonate dehydratases in terms of the biotransformation of hemicellulose sugars to chemicals

2020 ◽  
Vol 104 (16) ◽  
pp. 7023-7035
Author(s):  
Samuel Sutiono ◽  
Bettina Siebers ◽  
Volker Sieber
Keyword(s):  
Racemic Mixture ◽  
Highly Active ◽  
Key Points ◽  
Deoxy Sugar ◽  
Weimberg Pathway ◽  
One Step ◽  
The One ◽  
Increased Activity ◽  
Enzyme Class

Abstract2-keto-3-L-arabinonate dehydratase (L-KdpD) and 2-keto-3-D-xylonate dehydratase (D-KdpD) are the third enzymes in the Weimberg pathway catalyzing the dehydration of respective 2-keto-3-deoxy sugar acids (KDP) to α-ketoglutaric semialdehyde (KGSA). The Weimberg pathway has been explored recently with respect to the synthesis of chemicals from L-arabinose and D-xylose. However, only limited work has been done toward characterizing these two enzymes. In this work, several new L-KdpDs and D-KdpDs were cloned and heterologously expressed in Escherichia coli. Following kinetic characterizations and kinetic stability studies, the L-KdpD from Cupriavidus necator (CnL-KdpD) and D-KdpD from Pseudomonas putida (PpD-KdpD) appeared to be the most promising variants from each enzyme class. Magnesium had no effect on CnL-KdpD, whereas increased activity and stability were observed for PpD-KdpD in the presence of Mg2+. Furthermore, CnL-KdpD was not inhibited in the presence of L-arabinose and L-arabinonate, whereas PpD-KdpD was inhibited with D-xylonate (I50 of 75 mM), but not with D-xylose. Both enzymes were shown to be highly active in the one-step conversions of L-KDP and D-KDP. CnL-KdpD converted > 95% of 500 mM L-KDP to KGSA in the first 2 h while PpD-KdpD converted > 90% of 500 mM D-KDP after 4 h. Both enzymes in combination were able to convert 83% of a racemic mixture of D,L-KDP (500 mM) after 4 h, with both enzymes being specific toward the respective stereoisomer. Key points• L-KdpDs and D-KdpDs are specific toward L- and D-KDP, respectively.• Mg2+affected activity and stabilities of D-KdpDs, but not of L-KdpDs.• CnL-KdpD and PpD-KdpD converted 0.5 M of each KDP isomer reaching 95 and 90% yield.• Both enzymes in combination converted 0.5 M racemic D,L-KDP reaching 83% yield.

scholarly journals Chemistry and Mechanism of One-Step Formation of Graphene from Agrowaste

2020 ◽  
Vol 9 (3) ◽  
pp. 1389-1394
Keyword(s):  
Sugarcane Bagasse ◽  
High Performance ◽  
Graphene Nanosheets ◽  
Atmospheric Condition ◽  
Single Step ◽  
Xrd Pattern ◽  
Graphene Derivatives ◽  
One Step ◽  
The One ◽  
First Time

The one-step synthesis of high-quality graphene derivatives via CVD process has gained considerable importance nowadays for high-performance electronics and sensors. However, the use of harsh chemicals, high temperature, sensitivity, and the problem of separation of graphene from the substrate, motivated the one-step synthesis of graphene from a non-graphitic precursor, bypassing the use of graphite. In this paper, we have reported for the first time, the synthesis of graphene nanosheets from sugarcane bagasse at the normal atmospheric condition in a single step, avoiding the formation of GO. Here, the pyrolysis of sugarcane bagasse was carried out in the temperature range of 250-450o C in the presence of sodium hydroxide. The results suggested that even the low temperature (250–450o C) facilitated the development of graphitic planes via condensation and aromatization of the glucose monomers present in the precursor. The XRD pattern showed 2θ at around 25o in each case, which confirmed the formation of graphene instead of GO. The FESEM, TEM, and EDX analysis proved the formation of few-layer nanosheets of graphene from carbon-rich waste precursors in a single step.

Investigation of pyrolysis temperature in the one-step synthesis of L10 FePt nanoparticles from a FePt-containing metallopolymer

2015 ◽  
Vol 3 (4) ◽  
pp. 734-741 ◽  
Author(s):  
Qingchen Dong ◽  
Guijun Li ◽  
Hua Wang ◽  
Philip Wing-Tat Pong ◽  
Chi-Wah Leung ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Pyrolysis Temperature ◽  
Single Step ◽  
Fept Nanoparticles ◽  
Alloy Nanoparticles ◽  
Fept Alloy ◽  
One Step ◽  
The One

Ferromagnetic (L10 phase) FePt alloy nanoparticles (NPs) can be generated by single-step pyrolysis of metallopolymers. The influence of the pyrolysis temperature on the size and magnetic properties of these NPs were investigated.

scholarly journals One step Purification and Characterisation of Abrin Toxin from Abrus Precatorius Seeds

2019 ◽  
Vol 4 (4) ◽  
pp. 231-235
Author(s):  
Swati Banger ◽  
Rita Singh ◽  
Nagesh Tripathi ◽  
Vijai Pal ◽  
Ajay Kumar Goel
Keyword(s):  
Detection System ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Single Step ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plant Toxin ◽  
Abrus Precatorius ◽  
Catalytically Active ◽  
One Step ◽  
A Chain

Abrin is a plant toxin obtained from Abrus precatorius seeds. It belongs to the type II ribosomal inactivating proteins (RIPs) consisting of two chains namely, catalytically active A chain and sugar binding B chain linked by a single disulphide bond.  Due to high toxicity of abrin, its exposure or consumption can lead to serious public health problems. In the present work, we have extracted and purified the abrin toxin from Abrus precatorius seeds. The toxin was purified using a single step anion exchange chromatography. The purified protein was characterized by SDS-PAGE and MALDI- TOF to confirm its purity. The toxicity of purified abrin toxin was also confirmed by injecting the toxin in mice.  The purified protein was further used to raise antibodies in mice and characterized by indirect Enzyme Linked Immunosorbent Assay. The results of present study established the use of single step ion exchange chromatography to purify abrin toxin for further development of its detection system.

scholarly journals Purification of colony-stimulating factor by affinity chromatography

Blood ◽  
1982 ◽  
Vol 60 (1) ◽  
pp. 238-244 ◽  
Author(s):  
A Waheed ◽  
RK Shadduck
Keyword(s):  
Biochemical Characterization ◽  
Specific Activity ◽  
Low Ph ◽  
Single Step ◽  
Chromatographic Technique ◽  
Colony Stimulating Factor ◽  
L Cell ◽  
Rapid Purification ◽  
Sepharose 4B ◽  
Stimulating Factor

Abstract Studies were undertaken to determine whether L-cell-derived colony-stimulating factor (CSF) could be purified by a single step affinity chromatographic technique. A quantity of 100 X 10(6) units of purified anti-CSF was coupled to cyanogen bromide activated Sepharose 4B; colony assays revealed complete binding of the antibodies to the gel. Three 10- liter pools of serum-free L-cell CSF were concentrated by ultrafiltration, applied to the gel, and eluted with a low pH, high molarity buffer. Recovery of CSF ranged from 68%-100% with greater than 1000-fold decreases in protein content. Specific activity of the purified CSF ranged from 2.8 to 5.9 X 10(7) U of CSF/mg protein. Following iodination, each purified pool of CSF revealed a major 63,000- dalton peak of radioactivity that comigrated with CSF activity in SDS- acrylamide gels. In addition, several smaller peaks of 50,000 and 40,000 molecular weight were also detected. Approximately two-thirds of the purified CSF was adherent to concanavalin-A with elution by a competing sugar. Electrophoretic mobility was retarded by incubation with neuraminidase. These chromatographic studies confirm the observation that CSF is a glycoprotein but also suggest variable degrees of glycosylation of the molecule. This chromatographic technique should prove useful in the rapid purification of large quantities of CSF for physiologic and biochemical characterization.

Purification and Characterization of an Alkaline Protease from Bacillus alcalophilus

2012 ◽  
Vol 192 ◽  
pp. 285-288 ◽  
Author(s):  
Shan Shan Liu ◽  
Li Li Wang ◽  
Lin Yuan
Keyword(s):  
Alkaline Protease ◽  
Exchange Chromatography ◽  
Cation Exchange Chromatography ◽  
Ammonium Sulfate Precipitation ◽  
Purification And Characterization ◽  
Highly Active ◽  
Wide Range ◽  
Commercial Applications ◽  
Ph Range

The purification and characterization of an alkaline protease produced by Bacillus alcalophilus were investigated. The enzyme was purified in two steps: concentrating the crude enzyme using ammonium sulfate precipitation, followed by cation-exchange chromatography. The purified protease had a molecular mass of approximately 28 kDa, was highly active over an alkaline pH range of 10.0 to 11.0, and remained stable over a pH range of 7.0 to 12.0. The optimum temperature for the enzyme activity was found to be 40~60°C, while the thermotolerance of the enzyme was poor. Therefore, these characteristics of the protease indicate its potential for a wide range of commercial applications.

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