scholarly journals Cloning, Purification, and Partial Characterization ofBacillus subtilisUrate Oxidase Expressed inEscherichia coli

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Pollyana Pfrimer ◽  
Lidia Maria Pepe de Moraes ◽  
Alexsandro Sobreira Galdino ◽  
Loise Pedrosa Salles ◽  
Viviane Castelo Branco Reis ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Time Course ◽  
Single Step ◽  
Urate Oxidase ◽  
Inescherichia Coli ◽  
E Coli ◽  
Gene Coding ◽  
Step Procedure ◽  
Diagnostic Reagent ◽  
Optimal Ph

Urate oxidase (EC 1.7.3.3) is an enzyme involved in purine metabolism which is used in the treatment of gout and as diagnostic reagent for detection of uric acid. In order to produce this enzyme in large quantities for biotechnological purposes, the gene coding for theBacillus subtilisurate oxidase was cloned and heterologously expressed inEscherichia coli. Time course induction inE. colishowed an induced protein with an apparent molecular mass of∼60 kDa. Soluble recombinant enzyme was purified in a single-step procedure using Ni-NTA column. The enzyme was purified 2.1-fold with a yield of 56% compared to the crude extract. MALDI-TOF analysis revealed an ion with a mass of 58675 Da which is in agreement with the expected mass of the recombinant protein. The purified enzyme showed an optimal pH and temperature of 8.0 and37∘C, respectively, and retained 90% of its activity after 72 hours of incubation at −20∘Cand4∘C.

scholarly journals A Recombinant Multiepitope Protein for Hepatitis B Diagnosis

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Marilen Queiroz de Souza ◽  
Alexsandro Sobreira Galdino ◽  
José Carlos dos Santos ◽  
Marcus Vinicius Soares ◽  
Yanna C. de Nóbrega ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Time Course ◽  
Clinical Stage ◽  
Acute Infection ◽  
Single Step ◽  
Liver Inflammation ◽  
E Coli ◽  
Terminal Time ◽  
Gene Coding ◽  
B Virus

Hepatitis B is a liver inflammation caused by hepatitis B virus (HBV) and can be diagnosed in clinical stage by hepatitis B core antibody from IgM class (anti-HBcIgM). Hepatitis B core antibody from IgG class (Anti-HBcIgG) appears quickly after IgM, reaching high titers in chronic hepatitis, and remains even after cure. Since hepatitis B core antibody (anti-HBc) is the first antibody identified and sometimes the only marker detected during the course of infection, it can be used both to indicate HBV acute infection (anti-HBc-IgM) and to identify individuals who have come into contact with the virus (anti-HBc-IgG). In this work we propose a recombinant hepatitis B core multiepitope antigen (rMEHB) to be used for diagnosis of hepatitis B. For this purpose, a synthetic gene coding for rMEHB was designed and cloned into vector pET21a with a 6xHis tag at the C-terminal. Time course induction inE. colishowed an induced protein with an apparent molecular mass of ~21 kDa. Protein purification was performed by a single step with affinity chromatography Ni-NTA. Circular dichroism spectroscopy indicated rMEHB as a thermal stable protein at pH 7.0 and 8.0. In these conditions rMEHB was successfully used to perform an enzyme linked immuno sorbent assay (ELISA) with positive and negative sera.

scholarly journals A miniaturized biotyping system for strain discrimination inEscherichia coli

1993 ◽  
Vol 111 (1) ◽  
pp. 81-88
Author(s):  
P. B. Crichton ◽  
J. M. J. Logan ◽  
D. C. Old
Keyword(s):  
Escherichia Coli ◽  
Efficient Method ◽  
High Index ◽  
Inescherichia Coli ◽  
E Coli

SummaryA two-tier miniaturized scheme of eight tests was devised for biotyping strains ofEscherichia coliin microwell plates. Primary biotypes were defined by positive and negative reactions in tests for fermentation of raffinose, sorbose, dulcitol and 2-deoxy-D-ribose and for decarboxylation of ornithine when read after specified periods of incubation; subtypes were identified within primary biotypes according to results in secondary tests for rhamnose fermentation, lysine decarboxylation and motility. The method gave reproducible results on different occasions of testing.Among 100E. colistrains from various sources, 26 of the 32 possible primary biotypes and 56 full biotypes, as defined by results in both primary and secondary tests, were identified, thus demonstrating a high index of strain discrimination (D = 0·98).The scheme is recommended as a simple, reliable, inexpensive and efficient method of differentiating strains ofE. coli.

Evaluation of Structurally Different Carotenoids inEscherichia coli Transformants as Protectants against UV-B Radiation

1998 ◽  
Vol 64 (5) ◽  
pp. 1972-1974 ◽  
Author(s):  
Gerhard Sandmann ◽  
Silvia Kuhn ◽  
Peter B�ger
Keyword(s):  
Escherichia Coli ◽  
Inescherichia Coli ◽  
Short Term ◽  
E Coli ◽  
Carotenogenic Genes ◽  
Β Carotene

ABSTRACT Escherichia coli cells transformed with several carotenogenic genes to mediate the formation of ζ-carotene, neurosporene, lycopene, β-carotene, and zeaxanthin were exposed to UV-B radiation. Short-term kinetics revealed that endogenous levels of neurosporene and β-carotene protected E. coli against irradiation with UV-B. Zeaxanthin protected against only the photosensitized UV-B treatment. All other carotenoids were ineffective.

scholarly journals Optimization of the apolipoprotein B mRNA editing enzyme catalytic polypeptidelike-3G (APOBEC3G) gene to enhance its expression in Escherichia coli

2020 ◽  
Vol 29 (2) ◽  
pp. 120-8
Author(s):  
Rizkyana Avissa ◽  
Silvia Tri Widyaningtyas ◽  
Budiman Bela
Keyword(s):  
Escherichia Coli ◽  
Apolipoprotein B ◽  
Plasmid Vector ◽  
Nitrilotriacetic Acid ◽  
Mrna Editing ◽  
Specific Domain ◽  
Iptg Induction ◽  
E Coli ◽  
Gene Coding ◽  
Editing Enzyme

BACKGROUND Apolipoprotein B mRNA editing enzyme catalytic polypeptide-like-3G (APOBEC3G) can abolish HIV infection by inducing lethal mutations in the HIV genome. The HIV protein virion infectivity factor (Vif) can interact with APOBEC3G protein and cause its degradation. Development of a method that can screen substances inhibiting the APOBEC3G-Vif interaction is necessary for identification of substances that potentially used in anti-HIV drug development. In order to increase expression of recombinant APOBEC3G protein that will be used in APOBEC3G-Vif interaction assay, we developed an optimized APOBEC3G gene for expression in Escherichia coli.  METHODS The gene coding APOBEC3G was codon-optimized in accordance with prokaryotic codon using DNA 2.0 software to avoid bias codons that could inhibit its expression. The APOBEC3G gene was synthesized and sub-cloned into pQE80L plasmid vector. pQE80L containing APOBEC3G was screened by polymerase chain reaction, enzyme restriction, and sequencing to verify its DNA sequence. The recombinant APOBEC3G was expressed in E. coli under isopropyl-β-D-thiogalactoside (IPTG) induction and purified by using nickel-nitrilotriacetic acid (Ni-NTA) resin.  RESULTS The synthetic gene coding APOBEC3G was successfully cloned into the pQE80L vector and could be expressed abundantly in E. coli BL21 in the presence of IPTG.  CONCLUSIONS Recombinant APOBEC3G is robustly expressed in E. coli BL21, and the APOBEC3G protein could be purified by using Ni-NTA. The molecular weight of the recombinant APOBEC3G produced is smaller than the expected value. However, the protein is predicted to be able to interact with Vif because this interaction is determined by a specific domain located on the N-terminal of APOBEC3G. 

scholarly journals Glutathione-Dependent Conversion ofN-Ethylmaleimide to the Maleamic Acid by Escherichia coli: an Intracellular Detoxification Process

2000 ◽  
Vol 66 (4) ◽  
pp. 1393-1399 ◽  
Author(s):  
D. McLaggan ◽  
H. Rufino ◽  
M. Jaspars ◽  
I. R. Booth
Keyword(s):  
Escherichia Coli ◽  
Time Course ◽  
E Coli ◽  
Transient Activation ◽  
Low Concentrations ◽  
Maleamic Acid ◽  
High Concentrations ◽  
Hydrolysis Of ◽  
Strong Activator ◽  
Detoxification Process

ABSTRACT The electrophile N-ethylmaleimide (NEM) elicits rapid K+ efflux from Escherichia coli cells consequent upon reaction with cytoplasmic glutathione to form an adduct, N-ethylsuccinimido-S-glutathione (ESG) that is a strong activator of the KefB and KefC glutathione-gated K+ efflux systems. The fate of the ESG has not previously been investigated. In this report we demonstrate that NEM andN-phenylmaleimide (NPM) are rapidly detoxified by E. coli. The detoxification occurs through the formation of the glutathione adduct of NEM or NPM, followed by the hydrolysis of the imide bond after which N-substituted maleamic acids are released. N-Ethylmaleamic acid is not toxic to E. coli cells even at high concentrations. The glutathione adducts are not released from cells, and this allows glutathione to be recycled in the cytoplasm. The detoxification is independent of new protein synthesis and NAD+-dependent dehydrogenase activity and entirely dependent upon glutathione. The time course of the detoxification of low concentrations of NEM parallels the transient activation of the KefB and KefC glutathione-gated K+ efflux systems.

scholarly journals Characteristics of a New Enantioselective Thermostable Dipeptidase from Brevibacillus borstelensis BCS-1 and Its Application to Synthesis of a d-Amino-Acid-Containing Dipeptide

2004 ◽  
Vol 70 (3) ◽  
pp. 1570-1575 ◽  
Author(s):  
Dae Heoun Baek ◽  
Jae Jun Song ◽  
Seok-Joon Kwon ◽  
Chung Park ◽  
Chang-Min Jung ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Nucleotide Sequence ◽  
Amino Acid Sequence ◽  
Open Reading Frame ◽  
Nucleotide Sequence Analysis ◽  
Reading Frame ◽  
E Coli ◽  
Specificity Constant ◽  
Optimal Ph

ABSTRACT A new thermostable dipeptidase gene was cloned from the thermophile Brevibacillus borstelensis BCS-1 by genetic complementation of the d-Glu auxotroph Escherichia coli WM335 on a plate containing d-Ala-d-Glu. Nucleotide sequence analysis revealed that the gene included an open reading frame coding for a 307-amino-acid sequence with an M r of 35,000. The deduced amino acid sequence of the dipeptidase exhibited 52% similarity with the dipeptidase from Listeria monocytogenes. The enzyme was purified to homogeneity from recombinant E. coli WM335 harboring the dipeptidase gene from B. borstelensis BCS-1. Investigation of the enantioselectivity (E) to the P1 and P1′ site of Ala-Ala revealed that the ratio of the specificity constant (k cat /Km ) for l-enantioselectivity to the P1 site of Ala-Ala was 23.4 � 2.2 [E = (k cat /Km ) l,d /(k cat /Km ) d,d ], while the d-enantioselectivity to the P1′ site of Ala-Ala was 16.4 � 0.5 [E = (k cat /Km ) l,d /(k cat /Km ) l,l ] at 55�C. The enzyme was stable up to 55�C, and the optimal pH and temperature were 8.5 and 65�C, respectively. The enzyme was able to hydrolyze l-Asp-d-Ala, l-Asp-d-AlaOMe, Z-d-Ala-d-AlaOBzl, and Z-l-Asp-d-AlaOBzl, yet it could not hydrolyze d-Ala-l-Asp, d-Ala-l-Ala, d-AlaNH2, and l-AlaNH2. The enzyme also exhibited β-lactamase activity similar to that of a human renal dipeptidase. The dipeptidase successfully synthesized the precursor of the dipeptide sweetener Z-l-Asp-d-AlaOBzl.

scholarly journals Expression in Escherichia coli of human ARHGAP6 gene and purification of His-tagged recombinant protein.

2003 ◽  
Vol 50 (1) ◽  
pp. 239-247 ◽  
Author(s):  
Anna-Maria Ochocka ◽  
Marzena Czyzewska ◽  
Tadeusz Pawełczyk
Keyword(s):  
Escherichia Coli ◽  
Fusion Protein ◽  
Rho Gtpase ◽  
Expression System ◽  
Cloning And Expression ◽  
Soluble Form ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
Step Procedure ◽  
Shock Proteins

In this report we describe cloning and expression of human Rho GTPase activating protein (ARHGAP6) isoform 4 in Escherichia coli cells as a fusion protein with 6xHis. We cloned the ARHGAP6 cDNA into the bacterial expression vector pPROEX-1. Induction of the 6xHis-ARHGAP6 protein in BL21(DE3) and DH5alpha cells caused lysis of the cells irrespective of the kind of culture medium used. Successful expression of the fusion protein was obtained in the MC4100Deltaibp mutant strain lacking the small heat-shock proteins IbpA and IbpB. Reasonable yield was obtained when the cells were cultured in Terrific Broth + 1% glucose medium at 22 degrees C for 16 h. The optimal cell density for expression of soluble 6xHis-ARHGAP6 protein was at A(600) about 0.5. Under these conditions over 90% of the fusion protein was present in a soluble form. The 6xHis-ARHGAP6 protein was purified to near homogeneity by a two step procedure comprising chromatography on Ni-nitrilotriacetate and cation exchange columns. The expression system and purification procedure employed made it possible to obtain 1-2 mg of pure 6xHis-ARHGAP6 protein from 300 ml (1.5 g of cells) of E. coli culture.

scholarly journals Nucleotide sequence of a novel arylesterase gene from Vibro mimicus and characterization of the enzyme expressed in Escherichia coli

1994 ◽  
Vol 298 (3) ◽  
pp. 675-680 ◽  
Author(s):  
J F Shaw ◽  
R C Chang ◽  
K H Chuang ◽  
Y T Yen ◽  
Y J Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Cholesterol Acyltransferase ◽  
Reading Frame ◽  
Gene Coding ◽  
Step Procedure ◽  
Sds Page ◽  
Vibrio Mimicus ◽  
Hydrophobic Amino Acids ◽  
Cloned Gene

A gene coding for an arylesterase of Vibrio mimicus was cloned. Sequence determination reveals that the esterase gene has an open reading frame of 600 nucleotides which encodes a protein of M(r) 22,300. The deduced amino acid sequence contain a pentapeptide GDSLS (residues 27-31), which was also found in the phospholipid-cholesterol acyltransferase from Aeromonas hydrophila. Substitution of Ser-29 by alanine or cysteine in the cloned gene abolished the esterase activity in the tributyrin plate assay. On the other hand, the activity was not lost when Ser-31 was changed to alanine. The cloned gene was expressed in Escherichia coli, and the protein purified by a four-step procedure. The purified protein migrated on SDS/PAGE as a single band with an apparent M(r) of 22,100. This enzyme favoured the hydrolysis of several arylesters and was classified as an arylesterase (EC 3.1.1.2). N-Terminal analysis showed that Ser-20 was the first amino acid of the mature secreted protein, suggesting that the N-terminal 19 hydrophobic amino acids served as a signal peptide.

Uptake of exogenous DNA by plant protoplasts

1972 ◽  
Vol 50 (10) ◽  
pp. 2077-2080 ◽  
Author(s):  
Kanji Ohyama ◽  
Oluf L. Gamborg ◽  
Raymond A. Miller
Keyword(s):  
Escherichia Coli ◽  
Time Course ◽  
Cultured Cells ◽  
Incubation Temperature ◽  
Plant Protoplasts ◽  
Exogenous Dna ◽  
E Coli ◽  
Ammi Visnaga

Uptake by plant protoplasts isolated from cultured cells was demonstrated using Escherichia coli14C-DNA and Ammi visnaga protoplasts. About 0.6 to 2.8% of exogenous E. coli14C-DNA was taken up into the protoplasts, of which about 20% appeared to be acid-precipitable. The time course of uptake, the effect of incubation temperature, and the effects of DNA and protoplast concentration were studied. DEAE-dextran, poly-L-lysine, and poly-L-ornithine were found to enhance the uptake markedly.

The Aerobic Plate Count, Coliform and Escherichia coli Content of Raw Ground Beef at the Retail Level

1976 ◽  
Vol 39 (3) ◽  
pp. 175-178 ◽  
Author(s):  
J. M. GOEPFERT
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
New York ◽  
Ground Beef ◽  
The United States ◽  
Plate Count ◽  
Raw Meat ◽  
E Coli ◽  
Step Procedure ◽  
Aerobic Plate Count

Nine hundred fifty-five samples of raw ground beef obtained from supermarkets throughout the United States were examined for coliforms, Escherichia coli, and Aerobic Plate Count (APC). The results were compared with existent standards for E. coli in raw meat in New York and Oregon. Lack of homogenious distribution of E. coli in fresh ground beef was demonstrated. Observations were made that indicate that a 2 day-two step procedure will detect the same number of E. coli as the more time consuming four step MPN procedure 98% of the time. A comparison of the APC obtained by incubating plates at 20 C and 35 C showed there to be an average 10-fold difference with the 20 C incubation always higher. Questions are raised about the necessity of microbial standards for raw meat and the validity of incorporating E. coli in such standards.

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