Presence Of Sodium Dodecyl Sulfate Research Articles

Analysis of bovine serum albumin unfolding in the absence and presence of ATP by SYPRO Orange staining of agarose native gel electrophoresis

An attempt was made to specifically stain unfolded proteins on agarose native gels. SYPRO Orange is routinely used to detect unfolded protein in differential scanning fluorimetry, which is based on the enhanced fluorescence intensity upon binding to the unfolded protein. We demonstrated that this dye barely bound to the native proteins, resulting in no or faint staining of the native bands, but bound to and stained the unfolded proteins, on agarose native gels. Using bovine serum albumin (BSA), it was shown that staining did not depend on whether BSA was thermally unfolded in the presence of SYPRO Orange or stained after electrophoresis. On the contrary, SYPRO Orange dye stained protein bands in the presence of sodium dodecylsulfate (SDS) due to incorporation of the dye into SDS micelles that bound to the unfolded proteins. This staining resulted in detection of new, intermediately unfolded structure of BSA during thermal unfolding. Such intermediate structure occurred at higher temperature in the presence of ATP.

Synthesis of nickel oxide nanostructures and its application for acyclovir antivirus drug sensing in the presence of sodium dodecyl sulfate

Synthesis of nickel oxide nanostructures and its application for acyclovir antivirus drug sensing in the presence of sodium dodecyl sulfate

Trichothiodystrophy hair shafts display distinct ultrastructural features.

Hair shafts from three trichothiodystrophy (TTD) patients with mutations in the ERCC2 (XPD) gene were examined by transmission electron microscopy. TTD is a rare, recessive disorder with mutations in several genes in the DNA repair/transcription pathway, including ERCC2. Unlike previous studies, the hair shafts were examined after relaxation of their structure by partial disulphide bond reduction in the presence of sodium dodecyl sulphate, permitting improved visualization. Compared with hair shafts of normal phenotype, TTD cuticle cells displayed aberrant marginal bands and exocuticle layers. Clusters of cells stained differently (light versus dark) in the cortex of aberrant shafts, and the keratin macrofibrils appeared much shorter in the cytoplasm. Considerable heterogeneity in these properties was evident among samples and even along the length of single hair shafts. The results are consistent with not only a paucity of high sulphur components, such as keratin-associated proteins, but also a profound imbalance in protein content and organization.

The study of Piszkiewicz’s and Berezin’s models on the redox reaction of allylthiourea and bis-(2-pyridinealdoximato)dioxomolybdate(IV) complex in an aqueous acidic medium

BackgroundThe study of Piszkiewicz’s and Berezin’s models on the redox reaction of allylthiourea and bis-(2-pyridinealdoximato)dioxomolybdate(IV) complex ([MoIVO2(paoH)2]2−) in an aqueous acidic medium is suggested. The Piszkiewicz’s and Berezin’s models are applied, and their parameters are used to explain the redox behaviour of allylthiourea with Mo(IV) complex in the presence of surfactants.ResultsThe reaction followed a high cooperativity pattern that reflects a strong interaction between the two redox partners in the presence of cetyltrimethylammonium bromide (CTAB) which is reinforced by a notable binding constant at the Stern layer of the micelle. The effect of cationic counter-ion (Ca2+) on the reaction rate further confirmed the effectiveness of the interaction at the rate-limiting step. The presence of sodium dodecyl sulphate (SDS) in the reaction medium resulted in reaction inhibition which reveals the interplay of electrostatic repulsion at the electrophilic polar head of the surfactant and the redox species. The effect of ionic strength on the reaction rate shows that one of the reacting species is not charged (neutral) which kept the rate of the reaction uniform at different salt concentrations studied. The change in the medium polarity buttressed the effect of ionic strength on the reaction which is explained better by Piszkiewicz’s and Berezin’s models. Free radical was actively engaged in the reductive process of the Mo(IV) complex, and this revealed that the hydrophobic region is a possible location for the interaction of the redox partner in the presence of SDS micelle.ConclusionsThe models depict well the microenvironments of enzymatic reactions involving bimolecular interactions with significant binding constants and cooperativity indexes that show the strength of the interaction between the substrates and surfactant molecules.Graphical

Conductive electrospun composite fibers based on solid-state polymerized Poly(3,4-ethylenedioxythiophene) for simultaneous electrochemical detection of metal ions.

Conductive composite fibers containing poly (3,4-ethylenedioxythiophene) (PEDOT) and silver nanoparticles (AgNPs) were fabricated by emulsion electrospinning of 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) in toluene together with aqueous solution of poly (vinyl alcohol) (PVA) and silver nanoparticles (AgNPs) in the presence of sodium dodecylsulfate followed by heat treatment at 70°C to convert DBEDOT to conductive PEDOT via solid state polymerization (SSP). The composite fibers were characterized by scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and thermogravimetric analysis. The PEDOT/PVA/AgNPs composite fibers deposited on a screen-printed carbon electrode (SPCE) surface exhibited good electrochemical response and was applied for simultaneous detection of heavy metal ions in a mixture, namely Zn(II), Cd(II), and Pb(II) via square wave anodic stripping voltammetry (SWASV). With added Bi+3 into the detection system, the bismuth film formed on the electrode allows effective alloy formation with the deposited heavy metals obtained upon reduction of the heavy metal ions, the detection of heavy metal ions after stripping was successfully accomplished with a linear range of 10-80ppb and limits of detections (LOD) of 6, 3 and 8ppb for Zn(II), Cd(II), and Pb(II), respectively.

Poly(N-isopropylacrylamide) copolymer nanogels with thermogelling ability prepared by a single step of dispersion polymerization

The copolymer nanogels composed of two N-substituted acrylamides with different water solubility, N-isopropylacrylamide (NIPAM, water-soluble) and N-t-butylacrylamide (TBAM, water-insoluble), were prepared by free-radical polymerization in the presence of sodium dodecyl sulfate (SDS) as a dispersant and found to exhibit thermogelling ability at very low concentrations. To investigate the structure of the P(NIPAM-TBAM) nanogel and its formation mechanism in dispersion polymerization, we prepared the nanogels by changing the conditioning time, which is the time between the addition of SDS to the monomer solution and the start of polymerization, and compared the thermogelling properties of the resultant nanogels. As the conditioning time increased, (i) the hydrodynamic diameter of the nanogel decreased, (ii) the sol–gel and gel-syneresis transition temperatures of the nanogel dispersion decreased, and (iii) the storage moduli of the nanogel dispersion in a gel state increased. These results indicate that the P(NIPAM-TBAM) nanogel has a block-like structure composed of the TBAM-rich brushes and the NIPAM-rich core with three-dimensional polymer network, and that the TBAM ratio in the brushes increases with an increase in the conditioning time. It should be noted that the critical gelation concentration of the P(NIPAM-TBAM) nanogel dispersion was very low (∼1.3 wt%), compared with other thermogelling polymers reported in literatures. This low gelation concentration can be attributed to the gel structure of the nanogel core because the NIPAM-rich core can retain water inside even when the TBAM-rich brushes are dehydrated and crosslink with each other to induce gelation of the system.

Determination of Propranolol at a Carbon Paste Electrode Modified with Magnetite–Graphene Oxide in Combination with Presence of Sodium Dodecyl Sulfate

Determination of Propranolol at a Carbon Paste Electrode Modified with Magnetite–Graphene Oxide in Combination with Presence of Sodium Dodecyl Sulfate

One‐Step Synthesis of Degradable Vinylic Polymer‐Based Latexes via Aqueous Radical Emulsion Polymerization

AbstractAqueous emulsion copolymerizations of dibenzo[c,e]oxepane‐5‐thione (DOT) were performed with n‐butyl acrylate (BA), styrene (S) and a combination of both. In all cases, stable latexes were obtained in less than two hours under conventional conditions; that is in the presence of sodium dodecyl sulfate (SDS) used as surfactant and potassium persulfate (KPS) as initiator. A limited solubility of DOT in BA was observed compared to S, yielding to a more homogeneous integration of DOT units in the PS latex. In both cases, the copolymer could be easily degraded under basic conditions. Emulsion terpolymerization between DOT, BA and S allowed us to produce stable latexes not only composed of degradable chains but also featuring a broad range of glass transition temperatures.

One-Step Synthesis of Degradable Vinylic Polymer-Based Latexes via Aqueous Radical Emulsion Polymerization.

Aqueous emulsion copolymerizations of dibenzo[c,e]oxepane-5-thione (DOT) were performed with n-butyl acrylate (BA), styrene (S) and a combination of both. In all cases, stable latexes were obtained in less than two hours under conventional conditions; that is in the presence of sodium dodecyl sulfate (SDS) used as surfactant and potassium persulfate (KPS) as initiator. A limited solubility of DOT in BA was observed compared to S, yielding to a more homogeneous integration of DOT units in the PS latex. In both cases, the copolymer could be easily degraded under basic conditions. Emulsion terpolymerization between DOT, BA and S allowed us to produce stable latexes not only composed of degradable chains but also featuring a broad range of glass transition temperatures.

Experimental Evaluation of a Polymer Foam Agent on the Foam Stability, Concern to Surfactant, Nanoparticle, and Salinity

Summary In recent years, rising oil demand has led to a strong need to improve enhanced oil recovery (EOR) techniques. One of the most common methods for EOR in the oil industry is gas injection. When gas is injected into the reservoir, because of the low density of the gas relative to the oil and the undesirable gas mobility ratio, problems such as gas uptakes and the injected gas flow channeling arise, thus reducing the efficiency of oil production. Foam can improve mobility and increase EOR by reducing gas permeability. One of the most important properties of the foam is stability which affects the EOR. In recent years, many studies have been conducted on the use of nanoparticles (NPs) and polymers as stabilizers, but the use of stabilizers that have the ability to produce foam has been less studied. The main objective of this work is an experimental study of foam stability by the dynamic method of CO2 gas injection and static method of “Ross-Miles” in the presence of sodium dodecyl sulfate (SDS) and nanosilica in combination with a foaming polymer such as hydroxyethyl cellulose (HEC). The aim of this study was to compare the effect of a polymer that has the ability to produce foam relative to the stabilizer of NP on the foam stability. The zeta potential and the structure of the foam bubbles were measured to better understand the parameters affecting the foam stability. Experimental outcomes of this work show that the HEC polymer, despite being a foaming agent, has less effect on the foam stability than the nanosilica. That is, under similar conditions, SDS-NP based foams are more stable than SDS-HEC based foams. In addition, the composition of the SDS-NP-HEC foam system shows weaker foam performance compared to the case of SDS-NP and SDS-HEC dispersions. Also, salinity has an optimal concentration in which foam concentration has the best performance and stability; in this study, the optimal NaCl salt concentration is 2 wt% NaCl.

Purification and Identification of the 20S Proteasome Complex from Zebrafish.

The proteasome is a large polymeric protease complex responsible for degradation of intracellular proteins and generation of peptides. In this study, we purified a native 20S proteasome protein complex from zebrafish (Danio rerio) from the whole body. The cytosolic fraction of zebrafish hydrolyzed Suc-Leu-Leu-Val-Tyr-MCA (Suc-LLVY-MCA), a well-known substrate for the proteasome, in the presence of sodium dodecyl sulfate. From the cytosolic fraction, the 20S proteasome was purified using five column chromatography steps: DEAE cellulose, Q-Sepharose, Sephacryl S-300 gel, hydroxylapatite, and phenyl Sepharose. Electrophoresis and Western blot analyses showed that zebrafish 20S proteasome subunits have molecular masses ranging from 22 to 33 kDa. The subunit composition of the purified 20S proteasome was identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis after two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) separation. Fourteen kinds of 20S subunits were found. As a special characteristic of zebrafish, two proteins of the α1 subunit were identified. In addition, the results suggested that the α8 subunit is in the 20S complex instead of the α4 subunit. In this study, we demonstrated the subunit composition of the 20S proteasome complex present in zebrafish cells.

High rate performance of Lithium-ion batteries with Co-free LiNiO2 cathode

Co-free LiNiO2 (H-LNO) nanoparticles were synthesized by the urea-based hydrothermal synthesis in the presence of sodium dodecyl sulfate as an anionic surfactant, followed by a high-temperature calcination process with a lithium source. Compared to the LiNiO2 samples prepared via the co-precipitation method (C-LNO), the H-LNO samples exhibited superior electrochemical properties, such as charge/discharge capacity, rate capability, and cycle performance. Electrochemical tests showed that the H-LNO cathode reached an ultra-high initial discharge capacity of 211.9 mAh/g at 0.1C and maintained a capacity of 131.9 mAh/g at 5C, approximately twice greater than that of the C-LNO cathode. The H-LNO sample retained 77.33 % of its capacity, which is higher than that for the C-LNO sample (65.84 %) after 50 cycles at 0.5C. These results were attributed to the combined effect of the high Li+ diffusion coefficient and low charge transfer resistance, suggesting that the H-LNO powder is beneficial for practical applications in Li-ion batteries.

The Fluorescence Detection of Phenolic Compounds in Plicosepalus curviflorus Extract Using Biosynthesized ZnO Nanoparticles and Their Biomedical Potential.

A facile, eco-friendly fluorescence approach based on the biogenic formation of zinc oxide nanoparticles using the biomass of Plicosepalus curviflorus shoots was developed. The suggested approach was employed to analyze three phenolic compounds (catechin, curviflorside, and curviflorin) isolated from the shoots of P. curviflorus. The surface morphology of the prepared ZnONPs was characterized by carrying out different microscopic and spectroscopic investigations. A significant UV-Vis absorption peak of ZnONPs was recognized at 345 nm and the FT-IR spectra of the isolated catechin, curviflorside, and curviflorin in the presence of sodium dodecyl sulfate (SDS) and ZnONPs were recorded at λem 470, 490, and 484 nm after excitation at λex 380, 420, and 410 nm. The suggested fluorescence method displayed linear concentration ranges of 10–120, 5–100, and 10–150 μg mL−1 for the three isolated compounds, respectively. The shoot extract, isolated compounds, and ZnONPs were screened for antibacterial and anticancer effects against four different types of bacterial strains and HeLa cells, respectively. The ZnONPs exhibited the highest zone of inhibition against Escherichia coli and Staphylococcus aureus strains when compared with pure, isolated compounds and shoot extract. The anticancer potential of ZnONPs (64%) was stronger as compared to the 160 µg mL−1 of shoot extract (49%), catechin (52%), curviflorside (54%), and curviflorin (58%) at 160 µg mL−1. Moreover, all the samples were investigated for hemolysis activity and showed a potent anti-hemolytic effect. The developed analytical method showed excellent sensitivity and reliability for the concurrent analysis of the isolated bioactive markers.

Preparation and Characterization of Thermoresponsive Poly(N-vinylisobutyramide) Microgels.

Microgels are soft, adaptive materials exhibiting various properties not only like hydrogels and microparticles but also like macromolecules, colloids, and surfactants. To widen the range of their biomedical and environmental applications, the exploration of an alternative for poly(N-alkylacrylamide)s without potential safety risks is of great importance. In this article, thermoresponsive poly(N-vinylisobutyramide) (PNVIBA) microgels of uniform size were synthesized with NVIBA as a monomer and N,N'-5-oxanonamethyene-bis-N-vinylacetamide as a cross-linker in the presence of sodium dodecyl sulfate by aqueous free radical precipitation polymerization. The introduction of cationic groups into PNVIBA microgels was also accomplished using N-vinylformamide (NVF) as a comonomer and the subsequent conversion of NVF into vinylamine by hydrolysis.

Kaolinite colloidal suspensions under the influence of sodium dodecyl sulfate

Rheological properties of kaolinite particle suspensions in water were studied in the presence of sodium dodecyl sulfate (SDS). The characterization of slightly and strongly sonicated samples revealed the impact of particle initial clustering and agglomeration on their flow behavior; findings revealed that sonicated samples exhibit a stronger network. The influence of kaolinite concentration, sonication, and SDS loading on the apparent slip of kaolinite suspensions was also studied. The presence of SDS molecules prevents particle aggregation and network formation, which leads to a gradual reduction in yield stress. Through a suggested spatial hindrance mechanism, adding SDS above the minimum amount for micelle formation also stops network formation. Finally, it was found that increasing the concentration of kaolinite and sonication reduces the apparent slip, whereas increasing the surfactant concentration increases slip significantly. As a result of shear-induced migration, adding surfactant causes the interface to deplete and thus exhibit apparent slip.

Comparison of the influence of cationic polysaccharides on the stability properties of montmorillonite suspensions in the presence of sodium dodecyl sulphate

The mixtures of cationic cellulose (CC) or cationic guar gum (CGG) with the anionic sodium dodecyl sulfate surfactant (SDS) were used as stabilizers for the aqueous suspensions of montmorillonite (Mt). The stabilization processes and the stabilization mechanism were investigated using the UV-VIS. The obtained results show that both polysaccharides can be used as stabilizers of the water suspensions of montmorillonite due to the effective adsorption of CC and CGG with or without SDS on the Mt. surface. To obtain complete information on the studied systems, the additional measurements of the surface tension, zeta potential, FT-IR, XRD and SEM were made. The results prove that the intermolecular complexes formed between the polysaccharides and SDS can adsorb on the Mt. surface, change the structure of the electrical double layer and the stability properties of the studied suspensions.

Controlled Transdermal Iontophoresis of Insulin from Water-Soluble Polypyrrole Nanoparticles: An In Vitro Study.

The iontophoresis delivery of insulin (INS) remains a serious challenge due to the low permeability of the drug through the skin. This work aims to investigate the potential of water-soluble polypyrrole nanoparticles (WS-PPyNPs) as a drug donor matrix for controlled transdermal iontophoresis of INS. WS-PPyNPs have been prepared via a simple chemical polymerization in the presence of sodium dodecyl sulfate (SDS) as both dopant and the stabilizing agent. The synthesis of the soluble polymer was characterized using field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), fluorescence spectroscopy, and Fourier transform infrared (FT–IR) spectroscopy. The loading mechanism of INS onto the WS-PPyNPs is based on the fact that the drug molecules can be replaced with doped dodecyl sulfate. A two-compartment Franz-type diffusion cell was employed to study the effect of current density, formulation pH, INS concentration, and sodium chloride concentration on anodal iontophoresis (AIP) and cathodal iontophoresis (CIP) of INS across the rat skin. Both AIP and CIP delivery of INS using WS-PPyNPs were significantly increased compared to passive delivery. Furthermore, while the AIP experiment (60 min at 0.13 mA cm–2) show low cumulative drug permeation for INS (about 20.48 µg cm−2); the CIP stimulation exhibited a cumulative drug permeation of 68.29 µg cm−2. This improvement is due to the separation of positively charged WS-PPyNPs and negatively charged INS that has occurred in the presence of cathodal stimulation. The obtained results confirm the potential applicability of WS-PPyNPs as an effective approach in the development of controlled transdermal iontophoresis of INS.

A Green Approach for Photometric Determination of Copper β-Resorcylate in Double Base Solid Propellants

This paper describes the applicability of micellar media instead of extraction steps with toxic solvents for direct determination of copper beta-resorcylate as burning rate catalyst in double base propellant (DB propellant). The method is based on a simple and safe sample preparation of DB propellant, and then complex formation of copper ion with Diethyldithiocarbamate (DDTC) in the presence of sodium dodecyl sulfate (SDS) as a micellar media. Under optimal conditions, at λmax= 445 nm, the calibration graph was linear in the range of 0.25-4.5 µg mL-1 for copper with detection limits 0.125 µg mL-1. The validity of the method was evaluated by means of the data statistical analysis. For this purpose, the method was applied to the determination of copper beta-resorcylate in DB propellant and the results were statistically compared based on t- and F-tests with those obtained by the by ICP-AES. There was no significant difference between the mean values and the precisions of the two methods at the 95% confidence level. The results showed that the proposed method offers an accuracy and reliable approach for the determination of copper β-resorcylate in DB propellant, and can be suggested as a routine method in military quality control laboratories.

The effect of exogenous factors on the polyenzymatic activity of RuBisCO and ATP synthase of chloroplasts from pea leaves

Aim. To isolate and purify protein complexes – ATP synthase and RuBisCO – from pea leaf chloroplasts and study the effect of a microbiological fertilizer “Extracon” and sulfonamide inhibitors acetazolamide and ethoxyzolamide on the enzymatic activity of these proteins.Materials and methods. Chloroplasts were isolated from the leaves of two-week-old pea sprouts, protein complexes of purified thylakoid membranes were solubilized with digitonin (10 mg of digitonin per 1 mg of protein), the protein concentration was determined according to Lowry. Native electrophoresis with displacement of the charge of the soluble protein fraction from the chloroplast stroma, as well as membrane proteins, was carried out in the modified system of Anderson et al., Kolisnichenko et al. A modified Lemmley system was applied to the protein electrophoresis in the polyacrylamide gel in the presence of sodium dodecyl sulfate. The methods of Alain and Hintsik, as well as Gomorrah were used to determine the ATPase activity in the polyacrylamide gel. Visualization of the carbonic anhydrase activity in the polyacrylamide gel was performed by the method of Edwards and Petton. Results and discussion. Using physicochemical methods of potentiometry, spectrophotometry the ATPase, carbonic anhydrase and esterase activities of the enzymes were studied. The results obtained indicate that specific carbonic anhydrase inhibitors (acetazolamide and ethoxyzolamide) also block the esterase and ATPase activity of the enzyme complexes. “Extracon” (a multifunctional microbiological preparation) almost 1.5 times increases the activity of the enzymes, showing a complex activating effect of the fertilizer on both light and dark reactions of photosynthesis.Conclusions. The method of identification and isolation of RuBisCO and ATP synthase on the basis of two-dimensional electrophoresis and electrophoretic elution has been proposed. It allows determining the presence of certain enzyme activity of complexes at first in SDS plates (express analysis) and further to study the effect of various factors of endogenous and exogenous origin on the enzymatic properties of electrophoretically pure enzymes. The use of two-dimensional electrophoresis as a tool for assessing the impact of various factors of endogenous and exogenous origin on the plant cell and the plant as a whole through constant monitoring of the work and activity of enzyme systems of the plant cell is promising.

Synthesis of mixed phase crystalline CoNi2S4 nanomaterial and selective mechanism for adsorption of Congo red from aqueous solution

Calcination is an important factor to obtain crystalline nanomaterial with well-developed morphologies. A new adsorbent, crystalline CoNi2S4 was synthesized by sulfuration reactions with thioacetamide and metal precursors in the presence of sodium dodecyl sulfate (SDS) followed by calcination at different temperatures. Powder X-ray diffraction (PXRD) patterns suggested that the nanomaterial consists of a mixture of cubic and hexagonal phase, and crystallinity and crystallite size increases upon increasing the calcination temperature. SEM (scanning electron microscopy) micrographs concluded the formation of different shapes and sizes of nanomaterials at different temperatures. TEM (Transmission electron microscopy) analyses confirmed cactus tree-like morphology with hexagonal and cubic lattice fringes. The adsorption performance study showed that the nanomaterial exhibited a selective adsorption mechanism towards the adsorption of congo red (CR) among other dyes. The nanomaterial displayed a very high adsorption capacity of CR i.e. 2884 mg g–1. Moreover, the adsorption of CR is best fitted with pseudo-first-order kinetics and the modified Zhu and Gu isotherm model. The adsorption mechanism was investigated in detail through FTIR (Fourier-transform infrared), zeta potential and UV–Vis studies and thereby deliberate the possible interactions present between CR and CoNi2S4 nanomaterial. These results displayed high adsorption ability towards the dyes containing both amine (–NH2/NH) and azo (–NN–) groups. Adsorption occurred mainly through hydrogen bonding and metal coordination between the molecules of dye and the adsorbent followed by π-π interactions between dyes. Overall results suggested that the nanomaterial could be the prominent adsorbent for the removal of CR pollutants from water.