scholarly journals Molecular Characterization of KatY (Antigen 5), a Thermoregulated Chromosomally Encoded Catalase-Peroxidase of Yersinia pestis

1999 ◽  
Vol 181 (10) ◽  
pp. 3114-3122 ◽  
Author(s):  
Emilio Garcia ◽  
Yuri A. Nedialkov ◽  
Jeffrey Elliott ◽  
Vladimir L. Motin ◽  
Robert R. Brubaker
Keyword(s):  
Molecular Mass ◽  
Yersinia Pestis ◽  
Yersinia Pseudotuberculosis ◽  
Rabbit Antiserum ◽  
Deae Cellulose ◽  
Recognition Sequence ◽  
E Coli ◽  
Catalase Peroxidase ◽  
A Minor

ABSTRACT The first temperature-dependent proteins (expressed at 37°C, but not 26°C) to be identified in Yersinia pestis were antigens 3 (fraction 1), 4 (pH 6 antigen), and 5 (hereafter termed KatY). Antigens 3 and 4 are now established virulence factors, whereas little is known about KatY, except that it is encoded chromosomally, produced in abundance, possesses modest catalase activity, and is shared by Yersinia pseudotuberculosis, but notYersinia enterocolitica. We report here an improved chromatographic method (DEAE-cellulose, calcium hydroxylapatite, and Sephadex G-150) that yields enzymatically active KatY (2,423 U/mg of protein). Corresponding mouse monoclonal antibody 1B70.1 detected plasminogen activator-mediated hydrolysis of KatY, and a polyclonal rabbit antiserum raised against outer membranes of Y. pestis was enriched for anti-KatY. A sequenced ∼16-kb Y. pestis DNA insert of a positive pLG338 clone indicated thatkatY encodes an 81.4-kDa protein (pI 6.98) containing a leader sequence of 2.6 kDa; the deduced molecular mass and pI of processed KatY were 78.8 kDa and 6.43, respectively. A minor truncated variant (predicted molecular mass of 53.6 kDa) was also expressed. KatY is similar (39 to 59% identity) to vegetative bacterial catalase-peroxidases (KatG in Escherichia coli) and is closely related to plasmid-encoded KatP of enterohemorrhagic E. coli O157:H7 (75% identity). katY encoded a putative Ca2+-binding site, and its promoter contained three homologues to the consensus recognition sequence of the pCD-encoded transcriptional activator LcrF. rbsA was located upstream of katY, and cybB, cybC,dmsABC, and araD were mapped downstream. These genes are not linked to katG or katP inE. coli.

Identification and physical characterization of a Col E1 hybrid plasmid containing a catalase gene of Escherichia coli

1983 ◽  
Vol 61 (12) ◽  
pp. 1315-1321 ◽  
Author(s):  
Peter C. Loewen ◽  
Barbara L. Triggs ◽  
Glen R. Klassen ◽  
Joel H. Weiner
Keyword(s):  
Escherichia Coli ◽  
Catalase Activity ◽  
Physical Map ◽  
Polyacrylamide Gel Electrophoresis ◽  
Hybrid Plasmid ◽  
E Coli ◽  
Catalase Gene ◽  
Restriction Sites ◽  
Catalase Peroxidase

A hybrid Escherichia coli: Col E1 plasmid, pLC36-19, containing a catalase gene has been identified in the Clarke and Carbon colony bank. Catalase activity was amplified two- to three-fold in the pLC36-19-containing strain relative to other hybrid-plasmid-containing strains and this activity could be induced three- or four-fold by hydrogen peroxide or ascorbic acid. The plasmid was transferred to a strain chromosomally deficient in catalase synthesis, resulting in a strain with high and inducible levels of catalase. The plasmid was also transferred to a minicell-producing strain and minicells harbouring the plasmid were found to synthesize a labelled protein with a molecular weight of 84 000 characteristic of catalase from E. coli. A catalase activity was also synthesized by the plasmid-containing minicells. Two catalase activities with associated peroxidase activities coded for by the plasmid were separable by polyacrylamide gel electrophoresis and migrated coincident with chromosomally encoded catalase–peroxidase activities. A third catalase activity which did not have an associated peroxidase activity was not coded for by the plasmid. A physical map of the 25.5-kilobase pair plasmid was constructed by restriction nuclease analysis and the relative positions of 38 restriction sites were defined.

scholarly journals Localization and characterization of two structurally different forms of acetyl-CoA carboxylase in young pea leaves, of which one is sensitive to aryloxyphenoxypropionate herbicides

1994 ◽  
Vol 300 (2) ◽  
pp. 557-565 ◽  
Author(s):  
C Alban ◽  
P Baldet ◽  
R Douce
Keyword(s):  
Molecular Mass ◽  
Subunit Structure ◽  
Acetyl Coa Carboxylase ◽  
Leaf Extracts ◽  
Acetyl Coa ◽  
Native Molecular Mass ◽  
Molecular Masses ◽  
Minor Form ◽  
A Minor

Young pea leaves contain two structurally different forms of acetyl-CoA carboxylase (EC 6.4.1.2; ACCase). A minor form, which accounted for about 20% of the total ACCase activity in the whole leaf, was detected in the epidermal tissue. This enzyme was soluble and was purified to homogeneity from young pea leaf extracts. It consisted of a dimer of two identical biotinyl subunits of molecular mass 220 kDa. In this respect, this multifunctional enzyme was comparable with that described in other plants and in other eukaryotes. A predominant form was present in both the epidermal and mesophyll tissues. In mesophyll protoplasts, ACCase was detected exclusively in the soluble phase of chloroplasts. This enzyme was partially purified from pea chloroplasts and consisted of a freely dissociating complex, the activity of which may be restored by combination of its separated constituents. The partially purified enzyme was composed of several subunits of molecular masses ranging from 32 to 79 kDa, for a native molecular mass > 600 kDa. One of these subunits, of molecular mass 38 kDa, was biotinylated. This complex subunit structure was comparable with that of microorganisms and was referred to as a ‘prokaryotic’ form of ACCase. Biochemical parameters were determined for both ACCase forms. Finally, both pea leaf ACCases exhibited different sensitivities towards the grass ACCase herbicide, diclofop. This compound had no effect on the ‘prokaryotic’ form of ACCase, while the ‘eukaryotic’ form was strongly inhibited.

Detection and Isolation of Yersinia pestis Without Fraction 1 Antigen by Monoclonal Antibody in Foods and Water

2012 ◽  
Vol 75 (9) ◽  
pp. 1555-1561 ◽  
Author(s):  
TONG ZHAO ◽  
PING ZHAO ◽  
MICHAEL P. DOYLE
Keyword(s):  
Monoclonal Antibody ◽  
Yersinia Pestis ◽  
Magnetic Beads ◽  
Yersinia Pseudotuberculosis ◽  
Brain Heart Infusion ◽  
Enteric Bacteria ◽  
Immunoblot Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Whole Cells ◽  
A Minor

Most available immunoassays for Yersinia pestis are based on the detection of fraction 1 antigen (F1) when yersiniae are grown at 37°C. A monoclonal antibody (MAb) was developed based on the detection of surface antigens that are not F1. F1-deficient Y. pestis cells were induced and used to immunize BALB/c mice from which MAb (immunoglobulin G1), which specifically recognizes Y. pestis, with or without F1, was obtained. This MAb (6B5) did not cross-react with enteric bacteria, including Yersinia enterocolitica. Enzyme-linked immunosorbent assay results revealed that MAb 6B5 is specific for Y. pestis, with the exception of a minor cross-reaction with Yersinia pseudotuberculosis. Western immunoblot analysis revealed that MAb 6B5 recognizes a Y. pestis outer membrane protein of ca. 30 kDa. Magnetic beads that were coated with MAb 6B5 were compared with beads coated with polyclonal antibody (PAb; rabbit) against Y. pestis for the isolation of Y. pestis in food and water samples by using a PATHATRIX cell concentration apparatus. Enrichment cultures of Y. pestis in different foods by using two different times (6 and 24 h) in brain heart infusion broth at 37°C were evaluated. Results revealed MAb 6B5–coated magnetic beads were equivalent to magnetic beads coated with PAb against Y. pestis A1122 whole cells in concentrating Y. pestis for isolation, especially when samples were enriched for 6 h. However, the selectivity for Y. pestis of the magnetic beads coated with MAb 6B5 was greater than that coated with PAb.

scholarly journals Ferric Enterochelin Transport in Yersinia enterocolitica: Molecular and Evolutionary Aspects

1999 ◽  
Vol 181 (20) ◽  
pp. 6387-6395 ◽  
Author(s):  
S. Schubert ◽  
D. Fischer ◽  
J. Heesemann
Keyword(s):  
Gene Cluster ◽  
Yersinia Enterocolitica ◽  
Insertional Mutagenesis ◽  
Yersinia Pseudotuberculosis ◽  
Functional Characterization ◽  
In Vitro Transcription ◽  
E Coli ◽  
The Family

ABSTRACT Yersinia enterocolitica is well equipped for siderophore piracy, encompassing the utilization of siderophores such as ferrioxamine, ferrichrome, and ferrienterochelin. In this study, we report on the molecular and functional characterization of theYersinia fep-fes gene cluster orthologous to theEscherichia coli ferrienterochelin transport genes (fepA, fepDGC, and fepB) and the esterase gene fes. In vitro transcription-translation analysis identified polypeptides of 30 and 35 kDa encoded byfepC and fes, respectively. A frameshift mutation within the fepA gene led to expression of a truncated polypeptide of 40 kDa. The fepD,fepG, and fes genes of Y. enterocolitica were shown to complement corresponding E. coli mutants. Insertional mutagenesis of fepD orfes genes abrogates enterochelin-supported growth ofY. enterocolitica on iron-chelated media. In contrast toE. coli, the fep-fes gene cluster inY. enterocolitica consists solely of genes required for uptake and utilization of enterochelin (fep) and not of enterochelin synthesis genes such as entF. By Southern hybridization, fepDGC and fes sequences could be detected in Y. enterocolitica biotypes IB, IA, and II but not in biotype IV strains, Yersinia pestis, andYersinia pseudotuberculosis strains. According to sequence alignment data and the coherent structure of the Yersinia fep-fes gene cluster, we suggest early genetic divergence of ferrienterochelin uptake determinants among species of the familyEnterobacteriaceae.

scholarly journals Polyphenol Polymerization by an Alternative Oxidative Microbial Enzyme and Characterization of the Biological Activity of Oligomers

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Patrizia Di Gennaro ◽  
Valentina Sabatini ◽  
Silvia Fallarini ◽  
Roberto Pagliarin ◽  
Guido Sello
Keyword(s):  
Biological Activity ◽  
Oxidative Polymerization ◽  
Reaction Conditions ◽  
E Coli ◽  
Microbial Enzyme ◽  
Oligomeric Form ◽  
Catalase Peroxidase ◽  
Hplc Analyses

The recombinant catalase-peroxidase HPI from E. coli was used as an alternative enzyme in polymerization reactions for the production of (−) epicatechin oligomers and their biological activity was characterized. The enzyme was prepared in two forms: a purified and an immobilized form. Both were tested for their activity in oxidative polymerization reactions, and their stability and reusability were assessed. The polymerization reactions were followed by SEC-HPLC analyses, and the substrate was completely converted into one or more polymerization products depending on the reactions conditions. Results showed that the utilized conditions allowed for the isolation of some oligomers of different molecular weight: the oligomers containing 6 and 7 units of epicatechin substrate are the heaviest ones. Epicatechin was also used in reactions catalyzed by HRP in the same reaction conditions for comparison. In addition, one selected oligomer obtained by HPI enzyme catalysis was shown to act as in vitro inhibitor of tumor cell growth, like one oligomer deriving from epicatechin by HRP catalysis. These data confirm that epicatechin oligomeric form is more effective than its monomer in biological activity and suggest the use of HPI as an alternative enzyme in reactions for the production of epicatechin oligomers.

scholarly journals Proteomic Characterization of Yersinia pestis Virulence

2005 ◽  
Vol 187 (23) ◽  
pp. 8172-8180 ◽  
Author(s):  
Brett A. Chromy ◽  
Megan W. Choi ◽  
Gloria A. Murphy ◽  
Arlene D. Gonzales ◽  
Chris H. Corzett ◽  
...  
Keyword(s):  
Yersinia Pestis ◽  
Differentially Expressed ◽  
Virulence Determinants ◽  
Differentially Expressed Proteins ◽  
Mechanistic Studies ◽  
Differentially Expressed Protein ◽  
Catalase Peroxidase ◽  
Membrane Bound ◽  
Differential Gel Electrophoresis

ABSTRACT The Yersinia pestis proteome was studied as a function of temperature and calcium by two-dimensional differential gel electrophoresis. Over 4,100 individual protein spots were detected, of which hundreds were differentially expressed. A total of 43 differentially expressed protein spots, representing 24 unique proteins, were identified by mass spectrometry. Differences in expression were observed for several virulence-associated factors, including catalase-peroxidase (KatY), murine toxin (Ymt), plasminogen activator (Pla), and F1 capsule antigen (Caf1), as well as several putative virulence factors and membrane-bound and metabolic proteins. Differentially expressed proteins not previously reported to contribute to virulence are candidates for more detailed mechanistic studies, representing potential new virulence determinants.

scholarly journals Characterization of Chromosomal Regions Conserved in Yersinia pseudotuberculosis and Lost by Yersinia pestis

2008 ◽  
Vol 76 (10) ◽  
pp. 4592-4599 ◽  
Author(s):  
Flavie Pouillot ◽  
Corinne Fayolle ◽  
Elisabeth Carniel
Keyword(s):  
Yersinia Pestis ◽  
Yersinia Pseudotuberculosis ◽  
Rna Stability ◽  
Optimal Growth ◽  
Defined Medium ◽  
Open Reading Frames ◽  
Pcr Screening

ABSTRACT The transformation of the enteropathogenic bacterium Yersinia pseudotuberculosis into the plague bacillus, Yersinia pestis, has been accompanied by extensive genetic loss. This study focused on chromosomal regions conserved in Y. pseudotuberculosis and lost during its transformation into Y. pestis. An extensive PCR screening of 78 strains of the two species identified five regions (R1 to R5) and four open reading frames (ORFs; orf1 to orf4) that were conserved in Y. pseudotuberculosis and absent from Y. pestis. Their conservation in Y. pseudotuberculosis suggests a positive selective pressure and a role during the life cycle of this species. Attempts to delete two ORFs (orf3 and orf4) from the chromosome of strain IP32953 were unsuccessful, indicating that they are essential for its viability. The seven remaining loci were individually deleted from the IP32953 chromosome, and the ability of each mutant to grow in vitro and to kill mice upon intragastric infection was evaluated. Four loci (orf1, R2, R4, and R5) were not required for optimal growth or virulence of Y. pseudotuberculosis. In contrast, orf2, encoding a putative pseudouridylate synthase involved in RNA stability, was necessary for the optimal growth of IP32953 at 37°C in a chemically defined medium (M63S). Deletion of R1, a region predicted to encode the methionine salvage pathway, altered the mutant pathogenicity, suggesting that the availability of free methionine is severely restricted in vivo. R3, a region composed mostly of genes of unknown functions, was necessary for both optimal growth of Y. pseudotuberculosis at 37°C in M63S and for virulence. Therefore, despite their loss in Y. pestis, five of the nine Y. pseudotuberculosis-specific chromosomal loci studied play a role in the survival, growth, or virulence of this species.

scholarly journals Purification and biochemical characterization of recombinant human placental growth hormone produced in Escherichia coli

1993 ◽  
Vol 295 (3) ◽  
pp. 719-724 ◽  
Author(s):  
A Igout ◽  
J Van Beeumen ◽  
F Frankenne ◽  
M L Scippo ◽  
B Devreese ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Hormone ◽  
Molecular Mass ◽  
Biochemical Characterization ◽  
Expression System ◽  
Pituitary Hormone ◽  
Native Form ◽  
E Coli ◽  
Placental Growth Hormone

The hGH-V (or hGH-2) gene codes for human placental growth hormone (hPGH). Secretion of hPGH is continuous, in contrast with the pulsed secretion of pituitary growth hormone (hGH) which it progressively replaces in the maternal bloodstream. hGH-V cDNA has previously been cloned and isolated. Analysis of its nucleotide sequence has revealed a 191-residue protein, hPGH, differing from hGH at 13 positions. The calculated pI is more basic than that of the pituitary hormone. Here we have inserted hGH-V cDNA into the pIN-III-ompA3 plasmid in order to produce hPGH in its native form in Escherichia coli D1210. Expression of hGH-V cDNA in E. coli is significantly lower than that of hGH cDNA with the same expression system. The hPGH produced in E. coli was purified in quantities sufficient to allow its biochemical and immunochemical characterization. The molecular mass of the protein was determined by electrospray m.s. The determined mass, 22,320 Da, agrees well with the molecular mass calculated from the translated cDNA sequence, assuming the presence of two disulphide bridges. Having established the technique for producing hPGH with a primary structure identical to the natural, non-glycosylated, 22 kDa isoform, we can now plan the full physicochemical and pharmaceutical characterization of this new hormonal entity.

Cloning and characterization of chromosomally encoded cephalosporinase gene of Enterobacter cloacae

1986 ◽  
Vol 32 (4) ◽  
pp. 301-309 ◽  
Author(s):  
Sylvain Guerin ◽  
François Paradis ◽  
Roger Guay
Keyword(s):  
Escherichia Coli ◽  
Molecular Mass ◽  
Restriction Fragment ◽  
Initial Level ◽  
Plasmid Vector ◽  
Enterobacter Cloacae ◽  
Deletion Mapping ◽  
Genomic Fragment ◽  
E Coli

The cephalosporinase gene, cpa, which codes for an inducible class I chromosomal β-lactamase in Enterobacter cloacae was cloned on a fragment of 6.05 kilobase pairs inserted into plasmid pACYC184 and transferred into Escherichia coli HB101 recipient cells. The constructed hybrid plasmid, designated pGGQ101, carried a genomic fragment which retained its parental inducibility characteristics, although its expression level in transformed E. coli cells fell to 40–65% of its initial level in E. cloacae. The localization of the cpa gene on pGGQ101 plasmid was determined by Bal31 exonuclease deletion mapping and further confirmed by subcloning HindIII–AvaI restriction fragment on pMB9 plasmid vector. Labeling with [35S]methionine of pGGQ101 specified proteins in a minicell system showed that six or seven proteins are encoded by the insert. Two proteins with apparent molecular mass of 42 000 and 39 500 daltons, respectively, most probably represent the premature and mature cephalosporinase forms.

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