Incidence of plasmid DNA in Salmonella strains isolated from clinical sources in Ontario, Canada, during 1979 and 1980

1982 ◽  
Vol 28 (10) ◽  
pp. 1150-1157 ◽  
Author(s):  
Diane E. Taylor ◽  
Jessie G. Levine ◽  
Kallie L. Kouvelos
Keyword(s):  
Molecular Weight ◽  
Plasmid Dna ◽  
Gel Electrophoresis ◽  
Temperature Sensitive ◽  
Large Plasmid ◽  
Incompatibility Group ◽  
Transfer Resistance ◽  
Antibiotic Resistant ◽  
Molecular Weights ◽  
Resistant Strains

Gel electrophoresis of DNA from 70 clinical strains of Salmonella revealed a heterogeneous plasmid population. Plasmid DNA, ranging in molecular weight from 1.4 × 106 to 145 × 106, was demonstrated in 26 of 32 antibiotic-resistant strains. Several resistant strains carried up to six plasmids; however, of these, five strains which were multiply resistant contained a single plasmid of molecular weight 54 × 106 to 145 × 106. Only one incompatibility group H2 (IncH2) plasmid (pDT28) was detected in a strain of S. heidelberg; thus, this represents a reduction in the prevalence of these plasmids in Ontario Salmonella strains since 1974. The pDT28 plasmid resembled other IncH2 plasmids by its high molecular weight (145 × 106) and by virtue of its temperature-sensitive mode of transfer, resistance to tellurium, and inhibition of coliphage development. Of the 38 antibiotic-susceptible Salmonella strains, approximately half contained plasmids, ranging in molecular weight from 1.4 × 106 to 60 × 106. The plasmid-containing antibiotic-susceptible strains carried either a group of two to four small plasmids, with molecular weights less than 4.5 × 106, or a single large plasmid of molecular weight 23 × 106 or 60 × 106.

Studies on Soluble Fibrin Complexes as a Function of pH

1975 ◽  
Author(s):  
Y. Benabid ◽  
E. Concord ◽  
M. Suscillon
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Gel Electrophoresis ◽  
Gel Chromatography ◽  
Agarose Gel ◽  
Monomer Mixture ◽  
Soluble Fibrin ◽  
Molecular Weights ◽  
Fibrin Monomer

Purified fibrinogen solutions, incubated with thrombin. CNBr. Sepharose, were subjected to agarose gel chromatography and eluted at different pH (6.5; 7.5; 8.5). Among high molecular weight derivatives formed by thrombin, the major component was a dimer. Gel chromatography at pH 8.5 showed a complexes peak distinct of that from fibrinogen, whereas at pH 6.5, only the fibrinogen peak appeared: fibrin monomer was eluted with fibrinogen as demonstrated by polyacrylamid gel electrophoresis 3.75% pH 8.9. SDS urea electrophoresis after reduction indicated that complexes peak contained two α-chains (α and α′). When fibrinogen was incubated with thrombin in the presence of FSF and calcium, several derivatives with higher and higher molecular weights were formed besides the dimer, and elution profiles of chromatography were identical at pH 6.5 and 8.5, thus indicating stable complexes formation. If fibrinogen-fibrin monomer mixture was subjected to FSF action at different pH, no complexes were formed at pH 6.5. These results confirm that at pH 6.5, any association was prevented.

Studies on Molecular Weights of Two Peptide Hormones from the Urophysis of White Sucker (Catostomus commersoni)

1975 ◽  
Vol 53 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Graham Moore ◽  
Anita Letter ◽  
Maria Tesanovic ◽  
Karl Lederis
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Hypotensive Activity ◽  
White Sucker ◽  
Urotensin Ii ◽  
Catostomus Commersoni ◽  
Molecular Weights ◽  
Long Acting

The molecular weights of two active principles extracted from the urophysis of the teleost fish Catostomus commersoni in 0.1 N HCl or in 0.25% acetic acid have been investigated by gel filtration chromatography and SDS–polyacrylamide gel electrophoresis. Two peptides with urotensin I (long-acting rat hypotensive) activity and two peptides with urotensin II (fish smooth muscle stimulating) activity were found by these procedures. The smaller of the two urotensin I peptides (molecular weight 1200–1700), designated urotensin IS, was shown to be a fragment of the larger peptide (molecular weight 2300–3000) which is produced by acid hydrolysis without loss of rat hypotensive activity. The two urotensin II peptides are suggested to represent either a monomer and a dimer or open and closed forms of a peptide.

scholarly journals MITOCHONDRIAL RNA FROM CULTURED ANIMAL CELLS

1970 ◽  
Vol 46 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Bland S. Montenecourt ◽  
Margaret E. Langsam ◽  
Donald T. Dubin
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cell Lines ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Base Composition ◽  
Size Class ◽  
Mitochondrial Rna ◽  
Animal Cells ◽  
Molecular Weights

Discrete RNA fractions sedimenting slightly slower than 18s ribosomal RNA have been found in mitochondrial preparations from both hamster (BHK-21) and mouse (L-929) cells. This RNA could be separated into two components, present in approximately equimolar amounts, by prolonged zonal centrifugation or acrylamide gel electrophoresis. The hamster components had sedimentation constants averaging 16.8 and 13.4, and molecular weights (estimated by gel electrophoresis) averaging 0.74 and 0.42 x 106 daltons. Mixed labeling experiments showed that the mouse components sedimented and electrophoresed 3–6% more slowly than the corresponding hamster components. The RNA from both cell lines resembled mitochondrial ribosomal RNA from yeast and Neurospora in being GC poor, and in addition the larger and smaller components resembled each other in base composition. These results, taken with those of other recent studies, are compatible with the idea that our high molecular weight mitochondrial RNA is ribosomal; such RNA would then constitute a uniquely small size-class of ribosomal RNA.

scholarly journals Variations in the Methionine-rich Protein Composition of the Genus Arachis1

1984 ◽  
Vol 11 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Sheikh M. Basha ◽  
Sunil K. Pancholy
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Protein Composition ◽  
Electrophoretic Analysis ◽  
Two Dimensional ◽  
Weight Group ◽  
Two Dimensional Gel Electrophoresis ◽  
One Dimensional ◽  
Molecular Weights ◽  
Isoelectric Points

Abstract Methionine-rich proteins (MRP) from seeds of different species of the Genus Arachis were isolated and analyzed by gel electrophoresis to detect possible compositional differences. One-dimensional gel electrophoretic analysis showed presence of quantitative and qualitative variations among the MRP-fractions. Following two-dimensional gel electrophoresis, the MRP-fractions were found to contain three groups of polypeptides with apparent molecular weights of approximately 21,000; 19,000 and 16,000, and isoelectric points between 5.1 and 5.8. Within each molecular weight group the number of polypeptides varied between 1 and 3.

scholarly journals Purification and subunit structure of legumin of Vicia faba L. (broad bean)

1974 ◽  
Vol 141 (2) ◽  
pp. 413-418 ◽  
Author(s):  
David J. Wright ◽  
Donald Boulter
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Broad Bean ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Exchange Chromatography ◽  
Polyacrylamide Gel ◽  
Subunit Structure ◽  
Isoelectric Precipitation ◽  
Molecular Weights

Zonal isoelectric precipitation was shown to be an effective method for the preparation of legumin which was homogeneous as judged by ultracentrifugation and polyacrylamide-gel electrophoresis. The subunit structure of legumin was investigated by preparative sodium dodecyl sulphate–polyacrylamide-gel electrophoresis and ion-exchange chromatography in urea. Five distinct subunits, of which two were acidic (α) and had a molecular weight of 37000, and three were basic (β) with molecular weights of 20100, 20900 and 23800, were identified. The α and β subunits were present in equimolar amounts in the legumin molecule and, in view of this and molecular-weight considerations, an α6β6 subunit model was proposed for legumin.

β-Galactosidase from Bacillus stearothermophilus

1976 ◽  
Vol 22 (6) ◽  
pp. 817-825 ◽  
Author(s):  
Richard E. Goodman ◽  
Dennis M. Pederson
Keyword(s):  
Activation Energy ◽  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Bacillus Stearothermophilus ◽  
Thermal Inactivation ◽  
Ph Dependence ◽  
Temperature Sensitive ◽  
Optimum Temperature ◽  
Arrhenius Activation Energy ◽  
Ph Optimum

Several strains of thermophilic aerobic spore-forming bacilli synthesize β-galactosidase (EC 3.2.1.23) constitutively. The constitutivity is apparently not the result of a temperature-sensitive repressor. The β-galactosidase from one strain, investigated in cell-free extracts, has a pH optimum between 6.0 and 6.4 and a very sharp pH dependence on the acid side of its optimum. The optimum temperature for this enzyme is 65 °C and the Arrhenius activation energy is about 24 kcal/mol below 47 °C and 16 kcal/mol above that temperature. At 55 °C the Km is 0.11 M for lactose and 9.8 × 10−3 M for o-nitrophenyl-β-D-galactopyranoside. The enzyme is strongly product-inhibited by galactose (Ki = 2.5 × 10−3 M). It is relatively stable at 50 °C, losing only half of its activity after 20 days at this temperature. At 60 °C more than 60% of the activity is lost in 10 min. However, the enzyme is protected somewhat against thermal inactivation by protein, and in the presence of 4 mg/ml of bovine serum albumin the enzyme is only 18% inactivated in 10 min at 60 °C. Its molecular weight, estimated by disc gel electrophoresis, is 215 000.

scholarly journals The fractionation, characterization, and subcellular localization of colony-stimulating activities released by the human monocyte-like cell line, GCT

Blood ◽  
1980 ◽  
Vol 56 (4) ◽  
pp. 717-727
Author(s):  
JF DiPersio ◽  
JK Brennan ◽  
MA Lichtman ◽  
CN Abboud ◽  
FH Kirkpatrick
Keyword(s):  
Molecular Weight ◽  
Cell Line ◽  
Gel Electrophoresis ◽  
Disulfide Bonds ◽  
Polyacrylamide Gel Electrophoresis ◽  
Human Monocyte ◽  
Colony Growth ◽  
Subcellular Fractionation ◽  
Molecular Weights ◽  
Cell Cytosol

GCT, a human monocyte-like cell line, has been shown to release biochemically distinct colony-stimulating activities (CSAs) for mouse and human marrows. These appear to be periodate-sensitive proteins with critical disulfide bonds. One, of molecular weight 145,000 daltons, stimulates macrophagic colony growth and is related to a 30,000-dalton molecule that also stimulates mouse growth. A 30,000-dalton CSA for human marrow can be separated from the 30,000-dalton mouse CSA by isoelectric focusing and gradient polyacrylamide gel electrophoresis. This distinction agrees with our previous finding of differential neutralization with anti-human urinary CSF antibody. The 30,000-dalton CSAs stimulate neutrophil, neutrophil-monocyte, and eosinophil colony growth in human marrow but only neutrophil and neutrophil-monocyte colonies in the mouse. Subcellular fractionation of GCT cells indicates that there are pools of preformed CSAs primarily associated with the cell cytosol that have similar apparent molecular weights to their secreted counterparts.

Analysis of proteins in rabbit pulmonary surfactant using monoclonal antibodies

1986 ◽  
Vol 250 (3) ◽  
pp. C460-C467 ◽  
Author(s):  
R. J. King ◽  
H. M. Martin ◽  
J. B. Baseman ◽  
J. Morrison-Plummer
Keyword(s):  
Molecular Weight ◽  
Monoclonal Antibodies ◽  
High Molecular Weight ◽  
Gel Electrophoresis ◽  
Pulmonary Surfactant ◽  
Polyacrylamide Gel Electrophoresis ◽  
Low Molecular Weight ◽  
Weight Group ◽  
Molecular Weights ◽  
Intermediate Group

We have used monoclonal antibodies developed against the apolipoproteins associated with pulmonary surfactant purified from rabbit lavage fluid to study the expression of epitopes common to these proteins. The pulmonary surfactant contained nearly 20 proteins, of which at least 10 were not derived from serum. Electrophoresis, with sulfhydryl reduction of these proteins indicated apparent molecular weights of approximately 155, 135, 125, and 115 X 10(3) (high-molecular-weight group); 80, 70, and 60 X 10(3) (intermediate group); and 18 through 10 X 10(3) (low-molecular-weight group). Two-dimensional polyacrylamide gel electrophoresis, in which the proteins were electrophoresed without reduction in the first dimension, but with sulfhydryl reduction in the second dimension, revealed that the 80, 70, and 60 X 10(3) proteins dissociated into proteins of nominal molecular weights of 40, 35, and 30 X 10(3), respectively. In contrast, the 125 and 115 X 10(3) proteins of the high-molecular-weight group contained a protein which could only be reduced to a minimum molecular weight of 55 to 60 X 10(3). Monoclonal antibodies generally were of three types: those that reacted strongly with the high-molecular-weight group and weakly with the intermediate group; those that reacted conversely; and those that reacted only with the low-molecular-weight group. Our results indicate that at least two different surfactant apolipoproteins, with differing minimum molecular weights in SDS-polyacrylamide gel electrophoresis, have common epitopes. Although these results cannot certify a physiological relationship between these proteins, they suggest that the intracellular synthesis or extracellular processing of surfactant apolipoproteins may be more complicated than predicted by the findings of previous experiments, perhaps involving the posttranslational assembly of one surfactant protein into oligomers which resist dissociation under the conditions used for the analyses.

scholarly journals ISOLATION AND PARTIAL CHARACTERIZATION OF MACRO- AND MICRONUCLEI FROM PARAMECIUM AURELIA

1972 ◽  
Vol 53 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Donald J. Cummings
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Calcium Ions ◽  
Gel Electrophoresis ◽  
Partial Characterization ◽  
Intact Cells ◽  
Molecular Weights ◽  
High Molecular Weight Species ◽  
Nonionic Detergents

A method was developed for the isolation of macro- and micronuclei from Paramecium aurelia. This method utilized ionic and nonionic detergents to rupture the intact cells, calcium ions and spermidine were employed to protect the nuclei, and the nuclei were purified by centrifugation. Macronuclei consisted of 22% DNA, 10% RNA, and 68% protein. Micronuclei were composed of 9% DNA, 11% RNA, and 80% protein. DNA from both macro- and micronuclei had a density of 1.687 g/cc in CsCl and 1.417 g/cc in Cs2SO4. These values corresponded to G + C content of about 23%. The RNA of macronuclei was examined by gel electrophoresis, and two high molecular weight species were identified having molecular Weights of 1.3 x 106 and 2.8 x 106 daltons. Three syngens were studied, and in each case the conditions for isolation of the nuclei were the same and no differences were observed in the properties of the nuclei.

Genetic studies of H group plasmids by bacteriophage P1 transduction

1981 ◽  
Vol 27 (2) ◽  
pp. 175-183 ◽  
Author(s):  
Diane E. Taylor ◽  
Jessie G. Levine ◽  
Godyne Sibay ◽  
Anthony Walter
Keyword(s):  
Molecular Weight ◽  
Tetracycline Resistance ◽  
Streptomycin Resistance ◽  
Mechanism Of Formation ◽  
Incompatibility Group ◽  
Genetic Studies ◽  
Bacteriophage P1 ◽  
Molecular Weights ◽  
Resistance Markers ◽  
P1 Transduction

Bacteriophage P1 transduction was used to study the incompatibility group H1 plasmid pRG1251, molecular weight 120 × 106, and the incompatibility group H2 plasmid pSD114, molecular weight 166 × 106. The order of resistance (R) determinants on pSD114 was deduced from transduction and segregation experiments to be chloramphenicol-tetracycline-kanamycin-streptomycin. Resistance to tellurium and to coliphages, which are properties also encoded by many H2 plasmids, were not transduced with the other markers. On pRG1251, the ampicillin and tetracycline resistance markers appear to be located together, as do the chloramphenicol, streptomycin, and sulfamethoxazole resistance markers. Frequently, blocks of R determinants were transposed to the P1 genome or to the Escherichia coli chromosome. P1 DNA was isolated which carried the chloramphenicol, streptomycin, and sulfamethoxazole markers from pRG1251 and had a molecular weight of 64 × 106. Other P1 prophages carried R determinants from pSD114 and had molecular weights of 86 × 106. A plasmid of molecular weight 124 × 106 was also isolated which contained incompatibility determinants from P1 (incompatibility group Y) and from the H2 group plasmid. The mechanism of formation of these unusual plasmid species is discussed.

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