Factors affecting the stability of O/W emulsion in BSA solution: Stabilization by electrically neutral protein at high ionic strength

The A filament of the striated muscle sarcomere is an ordered aggregate of one or a few species of proteins. Ordering of these filaments into a parallel array is the basis of birefringence in the A region, and loss of birefringence is therefore a measure of decreased order. Heating caused a large decrease in the birefringence of glycerinated rabbit psoas muscle fibers over a narrow temperature range (∼3°C) and a large decrease in both the birefringence and optical density of the A region of Drosophila melanogaster fibrils. These changes were interpreted as a loss of A filament structure and were used to define a transition temperature (Ttr) as a measure of the stability of the A region. Since the transition temperature was sensitive to pH, ionic strength, and urea, solvent conditions which often affect protein structure, it is an experimentally useful indicator for factors affecting the structure of the A filament. Fibers from glycerinated frog muscle were less stable over a wide pH range than fibers from glycerinated rabbit muscle, a fact which demonstrates a species difference in structure. Glycerinated rabbit fibrils heated to 70°C shortened to about 40% of their initial length. The extent of shortening was not correlated with the loss of birefringence, and phase-contrast microscopy showed that this shortening occurred in the I region as well as in the A region. This response may be useful for studying the I filament and actin in much the same way that the decrease in birefringence was used for studying the A filament and myosin. The observations presented show that some properties of muscle proteins can be studied essentially in situ without the necessity of first dispersing the structure in solutions of high or low ionic strength.

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Study of the Stability of Functionalized Gold Nanoparticles for the Colorimetric Detection of Dipeptidyl Peptidase IV

Applied Sciences ◽

10.3390/app8122589 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2589 ◽

Cited By ~ 8

Author(s):

Hasan Aldewachi ◽

Nicola Woodroofe ◽

Philip Gardiner

Keyword(s):

Gold Nanoparticles ◽

Ionic Strength ◽

Biomedical Applications ◽

Colorimetric Detection ◽

Dipeptidyl Peptidase ◽

High Ionic Strength ◽

Dipeptidyl Peptidase Iv ◽

Au Nps ◽

Dpp Iv ◽

The Stability

In this report, we investigated three stabilization strategies of gold nanoparticles and their practical application for the visual detection of dipeptidyl peptidase IV (DPP-IV). Citrate-capped gold nanoparticles (Au NPs) are generally unstable in high-ionic-strength samples. Au NPs are easily tagged with various proteins and biomolecules rich in amino acids, leading to important biomedical applications including targeted drug delivery, cellular imaging, and biosensing. The investigated assays were based on different modes of stabilization, such as the incorporation of polyethylene glycol (PEG) groups, stabilizer peptide, and bifunctionalization. Although all approaches provided highly stable Au NP platforms demonstrated by zeta potential measurements and resistance to aggregation in a high-ionic-strength saline solution, we found that the Au NPs modified with a separate stabilizer ligand provided the highest stability and was the only platform that demonstrated sensitivity to the addition of DPP-IV, whilst PEGylated and peptide-stabilized Au NPs showed no significant response.

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Importance of Protease Inhibition in Studies on Purified Factor VIII (Antihaemophilic Factor)

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647943 ◽

1976 ◽

Vol 35 (01) ◽

pp. 186-190 ◽

Cited By ~ 6

Author(s):

Eugen A. Beck ◽

Peter Bachmann ◽

Peter Barbier ◽

Miha Furlan

Keyword(s):

Ionic Strength ◽

Factor Viii ◽

Gel Filtration ◽

High Ionic Strength ◽

Procoagulant Activity ◽

Carrier Protein ◽

Protease Inhibition ◽

Functional Sites ◽

Molecular Weight Peak ◽

Von Willebrand

SummaryAccording to some authors factor VIII procoagulant activity may be dissociable from carrier protein (MW~ 2 × 106) by agarose gel filtration, e.g. at high ionic strength. We were able to reproduce this phenomenon. However, addition of protease inhibitor (Trasylol) prevented the appearance of low molecular weight peak of factor VIII procoagulant activity both at high ionic strength and elevated temperature (37°C). We conclude from our results that procoagulant activity and carrier protein (von Willebrand factor, factor VIII antigen) are closely associated functional sites of native factor VIII macro molecule. Consequently, proteolytic degradation should be avoided in functional and structural studies on factor VIII and especially in preparing factor VIII concentrate for therapeutic use.

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THE RELATIVE DISTRIBUTION OF THYROXINE, TRIIODOTHYRONINE AND 3,3′,5′-(REVERSE)-TRIIODOTHYRONINE IN VARIOUS FRACTIONS OF THYROGLOBULIN

Acta Endocrinologica ◽

10.1530/acta.0.0880298 ◽

1978 ◽

Vol 88 (2) ◽

pp. 298-305 ◽

Cited By ~ 2

Author(s):

Peter Laurberg

Keyword(s):

Ionic Strength ◽

Guinea Pig ◽

Sucrose Gradient ◽

Deae Cellulose ◽

High Ionic Strength ◽

Relative Distribution ◽

Thyroid Extract ◽

Reverse Triiodothyronine ◽

Thyroid Secretion ◽

Stable Iodine

ABSTRACT Thyroglobulin fractions rich and poor in new thyroglobulin were separated by means of DEAE-cellulose chromatography of dog thyroid extracts and by zonal ultracentrifugation in a sucrose gradient of guinea pig thyroid extract incubated at low temperature. The distribution of thyroxine, triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine in hydrolysates of the different fractions was estimated by radioimmunoassays. Following DEAE-cellulose chromatography there was a small but statistically significant increase in the T4/T3 ratio in thyroglobulin fractions eluted at high ionic strength - that is fractions relatively rich in stable iodine but poor in fresh thyroglobulin. There were no differences in the T4/rT3 ratios between the different fractions. The ratios between iodothyronines were almost identical in the various thyroglobulin fractions following zonal ultracentrifugation in a sucrose gradient of cold treated guinea pig thyroid extract. These findings lend no support to the possibility that a relatively high content of triiodothyronines in freshly synthesized thyroglobulin modulates the thyroid secretion towards a preferential secretion of triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine at the expense of the secretion of thyroxine.

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Kaolin based protective barrier in municipal landfills against adverse chemo-mechanical loadings

Scientific Reports ◽

10.1038/s41598-021-89787-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Partha Das ◽

Tadikonda Venkata Bharat

Keyword(s):

Ionic Strength ◽

High Ionic Strength ◽

The Self ◽

Design Parameters ◽

Layered System ◽

Geosynthetic Clay Liners ◽

Clay Liners ◽

Landfill Liner ◽

First Time ◽

Applied Stresses

AbstractIn this work, we assess the self-sealing and swelling ability of the compacted granular bentonite (GB) under an inorganic salt environment and induced overburden stresses from the landfill waste. The laboratory permeation tests with high ionic strength salt solutions reveal that the GB fails to seal and exhibits a significant mechanical collapse under different applied stresses. The applicability of GB in the form of geosynthetic clay liners as the bottom liner facilities in landfills that produce high ionic strength salt leachates, therefore, remains a serious concern. We propose an additional barrier system based on kaolin, for the first time, to address this problem. The proposed kaolin-GB layered system performs satisfactorily in terms of its sealing and swelling ability even in adverse saline conditions and low overburden stresses. The kaolin improves the osmotic efficiency of the self and also helps the underlying GB layer to seal the inter-granular voids. The estimated design parameters by through-diffusion test suggest that the kaolin-GB layered system effectively attenuates the permeant flux and suitable as a landfill liner.

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Stabilizing effect of methylcellulose on the dispersion of multi-walled carbon nanotubes in cementitious composites

Nanotechnology Reviews ◽

10.1515/ntrev-2020-0009 ◽

2020 ◽

Vol 9 (1) ◽

pp. 93-104

Author(s):

Mingrui Du ◽

Yuan Gao ◽

Guansheng Han ◽

Luan Li ◽

Hongwen Jing

Keyword(s):

Carbon Nanotubes ◽

Pore Solution ◽

Cementitious Materials ◽

High Ionic Strength ◽

Cementitious Composites ◽

Uniform Distributions ◽

Stabilizing Effect ◽

Multi Walled Carbon Nanotubes ◽

The Stability ◽

Walled Carbon Nanotubes

AbstractMulti-walled carbon nanotubes (MWCNTs) have been added in the plain cementitious materials to manufacture composites with the higher mechanical properties and smart behavior. The uniform distributions of MWCNTs is critical to obtain the desired enhancing effect, which, however, is challenged by the high ionic strength of the cement pore solution. Here, the effects of methylcellulose (MC) on stabilizing the dispersion of MWCNTs in the simulated cement pore solution and the viscosity of MWCNT suspensions werestudied. Further observations on the distributions of MWCNTs in the ternary cementitious composites were conducted. The results showed that MC forms a membranous envelope surrounding MWCNTs, which inhibits the adsorption of cations and maintains the steric repulsion between MWCNTs; thus, the stability of MWCNT dispersion in cement-based composites is improved. MC can also work as a viscosity adjuster that retards the Brownian mobility of MWCNTs, reducing their re-agglomerate within a period. MC with an addition ratio of 0.018 wt.% is suggested to achieve the optimum dispersion stabilizing effect. The findings here provide a way for stabilizing the other dispersed nano-additives in the cementitious composites.

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