scholarly journals Introduction of a norA Promoter Region Mutation into the Chromosome of a Fluoroquinolone-Susceptible Strain ofStaphylococcus aureus Using Plasmid Integration

1999 ◽  
Vol 43 (9) ◽  
pp. 2222-2224 ◽  
Author(s):  
Glenn W. Kaatz ◽  
Susan M. Seo ◽  
Timothy J. Foster
Keyword(s):  
Molecular Weight ◽  
Promoter Region ◽  
Parent Strain ◽  
Susceptible Strain ◽  
Fluoroquinolone Resistance ◽  
Ofstaphylococcus Aureus ◽  
Molecular Weight Range ◽  
Similar Molecular Weight ◽  
Plasmid Integration ◽  
Integrating Vector

ABSTRACT It has been postulated that a mutation 11 bp 3′ to the −10 motif of the norA promoter is involved in the increased expression of the gene observed in some strains of Staphylococcus aureus exhibiting efflux-related fluoroquinolone resistance. Introduction of this mutation into the chromosome of a fluoroquinolone-susceptible strain by plasmid integration resulted in the minimum inhibitory concentrations of NorA substrates being increased, fluoroquinolone uptake being reduced, and norAexpression being enhanced. Diffuse hybridization of norAand integrating vector probes at a similar molecular weight range, higher than that of the norA transcript, was observed in the integrant, suggesting the possibility of a plasmid-based promoter contributing to norA expression. The ratio of the quantity of this transcript, which was also observed in the parent strain of the integrant, to the quantity of primary norA transcript was 0.14, demonstrating that it was unlikely that this mRNA species contributed significantly to the results observed. It is more likely that the introduced promoter region mutation does affect the expression of norA.

scholarly journals Nuclear matrix of HeLa S3 cells. Polypeptide composition during adenovirus infection and in phases of the cell cycle.

1977 ◽  
Vol 72 (1) ◽  
pp. 194-208 ◽  
Author(s):  
L D Hodge ◽  
P Mancini ◽  
F M Davis ◽  
P Heywood
Keyword(s):  
Cell Cycle ◽  
Molecular Weight ◽  
Nuclear Matrix ◽  
Apparent Molecular Weight ◽  
Molecular Weight Range ◽  
Weight Range ◽  
Molecular Weights ◽  
Liver Nuclei ◽  
Hela S3 ◽  
Biochemical Analyses

A subnuclear fraction has been isolated from HeLa S3 nuclei after treatment with high salt buffer, deoxyribonuclease, and dithiothreitol. This fraction retains the approximate size and shape of nuclei and resembles the nuclear matrix recently isolated from rat liver nuclei. Ultrastructural and biochemical analyses indicate that this structure consists of nonmembranous elements as well as some membranous elements. Its chemical composition is 87% protein, 12% phospholipid, 1% DNA, and 0.1% RNA by weight. The protein constituents are resolved in SDS-polyacrylamide slab gels into 30-35 distinguishable bands in the apparent molecular weight range of 14,000 - 200,000 with major peptides at 14,000 - 18,000 and 45,000 - 75,000. Analysis of newly synthesized polypeptides by cylindrical gel electrophoresis reveals another cluster in the 90,000-130,000 molecular weight range. Infection with adenovirus results in an altered polypeptide profile. Additional polypeptides with apparent molecular weights of 21,000, 23,000, and 92,000 become major components by 22 h after infection. Concomitantly, some peptides in the 45,000-75,000 mol wt range become less prominent. In synchronized cells the relative staining capacity of the six bands in the 45,000-75,000 mol wt range changes during the cell cycle. Synthesis of at least some matrix polypeptides occures in all phases of the cell cycle, although there is decreased synthesis in late S/G2. In the absence of protein synthesis after cell division, at least some polypeptides in the 45,000-75,000 mol wt range survive nuclear dispersal and subsequent reformation during mitosis. The possible significance of this subnuclear structure with regard to structure-function relationships within the nucleus during virus replication and during the life cycle of the cell is discussed.

Structure and Solution Properties of High Molecular Weight Butadiene-Styrene Copolymers

1957 ◽  
Vol 30 (1) ◽  
pp. 315-325
Author(s):  
R. B. MacFarlane ◽  
L. A. McLeod
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Complex Structure ◽  
Mixed Solvents ◽  
Solution Time ◽  
Solution Viscosity ◽  
Solution Properties ◽  
Molecular Weight Range ◽  
Viscosity Measurements ◽  
Commercial Practice

Abstract Production of high molecular weight copolymers of butadiene and styrene for use in oil-extended rubbers has aroused interest in the solution properties of copolymers above the molecular weight range commonly encountered in commercial practice. It has been observed that solubility of such polymers in toluene is a time-dependent phenomenon and the apparent solubility can increase continuously, in the absence of agitation, for as long as 800 hours. Although a standard Harris cage solubility test may show the presence of 50% gel, other properties do not confirm the presence of any appreciable quantities of insoluble material. Mild agitation rapidly promotes almost complete solubility. Dilute solution viscosity measurements are very misleading unless the influence of solution time is recognized and apparent intrinsic viscosities rise progressively with time of contact of the sample with solvent. This time-dependence of solution has been found to occur at conversions higher than 50% and is also a function of the amount of modifier used in the polymerization recipe. It has not been possible to shorten the solution time for viscosity measurements by mild heating or gentle agitation. Mixed solvents cause a change in the amount of increase of the apparent intrinsic viscosity but do not shorten the time to equilibrium. Measurement of the slope constant in the Huggins viscosity equation indicate that these solubility and viscosity effects coincide with the appearance of a marked degree of branching in the polymer molecules. The effect is, therefore, interpreted as being caused by the relatively slow disentanglement of molecules of complex structure.

A comparative study of the insoluble storage proteins and the lectins of seeds of the Euphorbiaceae

1984 ◽  
Vol 62 (8) ◽  
pp. 1671-1677 ◽  
Author(s):  
Louise Lalonde ◽  
David W. Fountain ◽  
Allison Kermode ◽  
Francis B. Ouellette ◽  
Kelly Scott ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Castor Bean ◽  
Storage Proteins ◽  
Reduced Form ◽  
Polyacrylamide Gels ◽  
Salt Solutions ◽  
Sodium Dodecylsulphate ◽  
Molecular Weight Range ◽  
Jatropha Gossypifolia ◽  
Major Storage Protein

The major storage protein within seeds of the Euphorbiaceae is the 11S crystalloid, which is only completely soluble in buffer or salt solutions if sodium dodecylsulphate or urea is present. Prior to this study, only the storage proteins of the castor bean had been characterized. The nonreduced crystalloid protein complex in all species tested has a molecular weight of 50 000 – 55 000, and in reduced form the proteins migrate on polyacrylamide gels as two distinct groups of polypeptides, one in the molecular weight range 20 000 – 25 000 and the other in the 29 000 – 35 000 range. In this respect the proteins have the general characteristics of those of castor bean, but only the proteins of Jatropha gossypifolia show striking similarities. Within any one genus, the storage proteins appear to be more or less identical (e.g., Manihot spp.) or show distinct differences (e.g., Euphorbia spp.). The soluble lectin proteins of J. gossypifolia have very similar haemagglutination properties to those of castor bean lectins, and the glycoproteins of both species separate similarly on polyacrylamide gels. Few other species contain glycoproteins or lectins that can cause agglutination.

scholarly journals Immunohistochemical and immunochemical characterization of a new endothelial cell-specific antigen.

1986 ◽  
Vol 34 (2) ◽  
pp. 209-214 ◽  
Author(s):  
J U Alles ◽  
K Bosslet
Keyword(s):  
Molecular Weight ◽  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Specific Antigen ◽  
Similar Molecular Weight ◽  
Immunochemical Characterization ◽  
Sds Page

A new monoclonal antibody (moab BW 200) of IgG3 kappa-isotype was generated which recognizes an epitope located on an antigen molecule restricted to human neoplastic and non-neoplastic endothelial cells. The molecular weight of the antigen was determined using immunoprecipitation analysis followed by SDS-PAGE. Despite its similar molecular weight to FVIII-RAG, the antigen detected by moab BW 200 was shown to be different from FVIII-RAG.

Uremic Neurotoxin in the Middle Molecular Weight Range

1980 ◽  
Vol 4 (2) ◽  
pp. 116-120 ◽  
Author(s):  
N.K. Man ◽  
G. Cueille ◽  
J. Zingraff ◽  
J. Boudet ◽  
A. Sausse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Range ◽  
Weight Range

scholarly journals Physicochemical and Antioxidant Properties of the Degradations of Polysaccharides from Dendrobium officinale and Their Suitable Molecular Weight Range on Inducing HeLa Cell Apoptosis

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaofeng Zhang ◽  
Yingyi Luo ◽  
Gang Wei ◽  
Yunrong Li ◽  
Yuechun Huang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Antitumor Activity ◽  
Hela Cells ◽  
Biological Activities ◽  
Antioxidant Properties ◽  
Mitochondrial Pathway ◽  
Influential Factor ◽  
Dendrobium Officinale ◽  
Molecular Weight Range ◽  
Pharmaceutical Industries

Different molecular weight polysaccharides of Dendrobium officinale (DOPs) have gradually attracted attention because of their broad biological activities. They, however, remain poorly defined whether their antitumor activity is associated with molecular weight. In this study, the physicochemical, antioxidant, and antitumor properties of DOPs, including the crude polysaccharide (DOP) and its six degradation fractions (DOP1–DOP6) extracted from Dendrobium officinale, were determined. Consequently, DOPs were mainly composed of different ratios of mannose and glucose as follows: 5.15 : 1, 4.62 : 1, 4.19 : 1, 4.46 : 1, 4.32 : 1, 4.29 : 1, and 4.23 : 1, and their molecular weights were significantly different ranging from 652.29 kDa to 11.10 kDa. With the concentration increase of DOPs, the scavenging capacity against OH and DPPH free radicals increased. The antitumor ability of DOPs was different that DOP1–DOP5 (Mw: 176.29 kDa–28.48 kDa) exhibited the best antiproliferation activity than DOP (Mw: 652.29 kDa) and DOP6 (Mw: 11.10 kDa) in HeLa cells rather than PC9, A549, and HepG2 cells. Moreover, it is worth mentioning that DOP1 and DOP5 showed stronger capability on inducing apoptosis of HeLa cells than DOP and DOP6 via the mitochondrial pathway by upregulating the ratio of the Bax/Bal-2 mRNA expression. The results demonstrated that DOPs can be used as the potential natural antioxidant and antitumor products in pharmaceutical industries, and the molecular weight is a crucial influential factor of their antitumor activity that 28.48 kDa–176.29 kDa is a suitable range we may refer to.

Aqueous polypropylene glycol induces swelling and severe plasticization of high Tg amphiphilic copolymers containing hexafluoroisopropanol groups

Soft Matter ◽  
2020 ◽  
Vol 16 (27) ◽  
pp. 6362-6370
Author(s):  
Siyuan Li ◽  
Bryan D. Vogt
Keyword(s):  
Molecular Weight ◽  
Propylene Glycol ◽  
Polypropylene Glycol ◽  
Amphiphilic Copolymers ◽  
Molecular Weight Range ◽  
Weight Range ◽  
Poly Propylene

Not too big, not too small, but a narrow molecular weight range for poly(propylene glycol) where swelling of the copolymer increases tremendously for poly(propylene glycol).

scholarly journals Experimental and Theoretical Studies of Carboxylic Polymers with Low Molecular Weight as Inhibitors for Calcium Carbonate Scale

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 406 ◽  
Author(s):  
Yuwei Zuo ◽  
Wenzhong Yang ◽  
Kegui Zhang ◽  
Yun Chen ◽  
Xiaoshuang Yin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Calcium Carbonate ◽  
Normal Growth ◽  
Dynamics Simulation ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
Crystal Surfaces ◽  
Molecular Weight Range ◽  
Scale Inhibition ◽  
Diffraction Patterns

Poly acrylic acid (PAA) and polyepoxysuccinic acid (PESA) were investigated as scale inhibitors. The static experiments certified that PAA was superior to PESA for the inhibition of calcium carbonate in the low molecular weight range. The X-ray diffraction patterns suggest that the effect of PAA on the calcite (1 0 4) and (1 1 0) crystal plane was more obvious. Scanning electron microscopy was used to study the surface morphology of the depositions, which indicated that the addition of scale inhibitors could disturb the normal growth of CaCO3 scale. The transmittance ratio of ferric oxide demonstrated that PAA had a better dispersion performance than PESA. The molecular dynamics simulation and quantum calculation were selected to theoretically explore the mechanism and structure of scale inhibitors, indicating that the interaction of PAA with (1 0 4) and (1 1 0) calcite crystal surfaces was stronger than PESA. In addition, the results indicated that the PAA with negative charge more easily adsorbed free Ca2+ in the aqueous phase. Based on these observations, PAA exhibited better scale inhibition and dispersion effects than PESA in the case of low molecular weight.

scholarly journals Lab-on-a-Chip method uncertanties in determination of high-molecular-weight glutenin subunits

2013 ◽  
Vol 19 (4) ◽  
pp. 553-561 ◽  
Author(s):  
Dragan Zivancev ◽  
Branislava Nikolovski ◽  
Aleksandra Torbica ◽  
Jasna Mastilovic ◽  
Nevena Djukic
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Wheat Variety ◽  
Lab On A Chip ◽  
Good Resolution ◽  
Glutenin Subunits ◽  
Bread Making ◽  
Molecular Weight Range ◽  
Essential Information ◽  
Significant Difference

Polymeric wheat endosperm proteins, especially the high-molecular-weight glutenin subunits (HMW-GS), are probably the most interesting protein fraction giving the essential information about bread-making quality of wheat flour. A relatively new method that shows a great potential for a fast, reliable and automatable analysis of protein purity, sizing and quantification is microfluidic or Lab-on-a-Chip (LoaC) capillary electrophoresis. This work was aimed to explore the possibilities of implementation of LoaC method to analysis of protein samples isolated from a Serbian common wheat variety, emphasizing the steps that might bring uncertainties and affect reproducibility of obtained glutenin subunits quantitation results. A good resolution of protein bands in a molecular weight range of 14.0 to 220.0 kDa was achieved. The reproducibility of HMW-GS sizing and quantitation were good, with the average coefficient of variation values of 1.2% and 12.2%. The ratio of HMW-GS to low-molecular-weight glutenin subunits (LMW-GS) was about 20%. The investigation ruled out influences of the extract solution addition and the buffer addition steps of the applied method, as well as the individual chip influence on GS quantitation results. However, there was statistically significant difference between HMW-GS quantitation results of multi-step and one-step extraction procedures applied prior to glutenin subunits extraction step.

scholarly journals The composition of peptidochitodextrins from sarcophagid puparial cases

1971 ◽  
Vol 125 (3) ◽  
pp. 703-716 ◽  
Author(s):  
H. Lipke ◽  
T. Geoghegan
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Protein Complex ◽  
Covalent Bonds ◽  
Aromatic Residues ◽  
Similar Molecular Weight ◽  
X Ray ◽  
Molecular Weights ◽  
Physical Interactions ◽  
The Stability

1. N-Bromosuccinimide cleaved proteins and pigments from fly puparia, increasing the chitin:protein ratio from 0.5 to 1.5. The product afforded subfractions (ratio 5:1) of molecular weights of 1200 and 1600 devoid of aromatic residues and N-terminal β-alanine, direct aryl links between polysaccharide chains being discounted. 2. The chitin–protein complex decreased in molecular weight when treated with Pronase, which suggested polypeptide bridges within the native chitin micelle. The limit dextrins generated by chitinase were mixtures of unsubstituted dextrins and peptidylated oligosaccharides, with the former predominating. 3. Peptidochitodextrins of similar molecular weight but markedly different solubility were prepared, which were indistinguishable with respect to amino acid, glucosamine, acetyl, X-ray or infrared characteristics. It is suggested that physical interactions contribute to the stability of the integument in addition to the covalent bonds that form during sclerotization.

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