Presence Of Triton X-100 Research Articles

Activation and Stabilization of The Hydroperoxide Lyase Enzymatic Extract from Mint Leaves (Mentha spicata) Using Selected Chemical Additives

The effects of selected lyoprotecting excipients and chemical additives on the specific activity and the thermal stability of the hydroperoxide lyase (HPL) enzymatic extract from mint leaves were investigated. The addition of KCl (5%, w/w) and dextran (2.5%, w/w) to the enzymatic extract, prior to lyophilization, increased the HPL specific activity by 2.0- and 1.2-fold, respectively, compared to the control lyophilized extract. From half-life time (t (1/2)), it can be seen that KCl has enhanced the HPL stability by 1.3- to 2.3-fold, during long-period storage at -20 degrees Celsius and 4 degrees Celsius. Among the selected additives used throughout this study, glycine appeared to be the most effective one. In addition to the activation effect conferred by glycine, it also enhanced the HPL thermal stability. In contrast, polyhydroxyl-containing additives were not effective for stabilizing the HPL enzymatic extract. On the other hand, there was no signification increase in HPL activity and its thermal stability with the presence of Triton X-100. The results also showed that in the presence of glycine (10%), the catalytic efficiency of HPL was increased by 2.45-fold than that without additive.

Nanobiosensors prepared by electrodeposition of glucose oxidase in PMMA nanochannels produced by atomic force microscopy nanolithography

Atomic force microscopy (AFM) nanolithography was employed to fabricate poly(methyl methacrylate) (PMMA) nanochannels with a width of 80 nm, a depth of 30 nm, and a length of up to 8 μm on a Pt-coated indium tin oxide substrate. Quasi-sigmoidal steady-state responses was observed in cyclic voltammograms for the Fe ( CN ) 6 4 - / Fe ( CN ) 6 3 - redox system in aqueous 0.1 M KCl at the patterned PMMA-coated Pt surface. The PMMA nanochannels were used to prepare glucose nanobiosensors by electrodeposition of glucose oxidase in the presence of Triton X-100. The height of the resulting glucose nanobiosensor was about 80 nm. The prepared glucose nanobiosensors displayed a sensitivity of 6.56 A M −1 cm −2 and a response time of less than 3 s. The sensitivity obtained in this study is much higher than those obtained at normal macroelectrodes. The present methodology demonstrates the feasibility of electrodeposition of glucose oxidase in PMMA nanochannels produced by AFM nanolithography for biosensing of glucose.

Purification of a vesicle–vacuole fraction functionally linked to aflatoxin synthesis in Aspergillus parasiticus

Current studies in our laboratory demonstrate a functional link between vesicles, vacuoles and aflatoxin biosynthesis in the filamentous fungus, Aspergillus parasiticus. Under aflatoxin inducing conditions in liquid yeast-extract sucrose medium, A. parasiticus undergoes a shift from vacuole biogenesis to accumulation of an enhanced number of vesicles which exhibit significant heterogeneity in size and density. As a first step in conducting a detailed analysis of the role of these organelles in aflatoxin synthesis, we developed a novel method to purify the vesicle and vacuole fraction using protoplasts prepared from cells harvested during aflatoxin synthesis. The method includes the following steps: 1] preparation of protoplasts from mycelia grown for 36 h under aflatoxin inducing conditions; 2] release of vesicles and vacuoles from purified protoplasts in the presence of Triton X-100; and 3] fractionation of the vesicles and vacuoles using a “one-step high density cushion”. The vesicle–vacuole fraction showed a 35 fold enrichment in alpha-mannosidase activity (vacuole marker) and non-detectable succinate dehydrogenase and lactate dehydrogenase activities (mitochondrial and cytoplasmic markers, respectively). Confocal laser scanning microscopy with the vacuole dyes MDY-64 and CMAC demonstrated that the fraction contained pure vesicles and vacuoles and was devoid of membranous debris. Transmission electron microscopy (TEM) confirmed that no mitochondria or unbroken protoplasts contaminated the purified fraction. The purified organelles exhibited significant size heterogeneity with a range of sizes similar to that observed in whole cells and protoplasts.

Coagulation of soil suspensions containing nonionic or anionic surfactants using chitosan, polyacrylamide, and polyaluminium chloride

Effective coagulation and separation of particles in a soil-washed solution is required for a successful soil washing process. The effectiveness of chitosan (CS), a polycationic biodegradable polymer, as a coagulant was compared to polyacrylamide (PAA) and polyaluminium chloride (PAC) for the coagulation of a soil suspension (5 g L −1). The effect of surfactants in the coagulation process was investigated using Triton X-100 (TX-100), a nonionic surfactant, and sodium dodecyl sulfate (SDS), an anionic surfactant. CS (5 mg L −1) removed 86% and 63% of the suspended soil in the presence of TX-100 (5 g L −1) and SDS (5 g L −1), respectively, after 30 min at a pH of 6. The results prove that coagulation in the presence of TX-100 is more effective than with SDS. CS was found to be more efficient compared to PAA and PAC under all coagulation conditions. The optimum concentration of CS required for maximum coagulation of soil suspension was 5 mg L −1. PAA and PAC could not achieve the same degree soil removal as CS even after increasing their concentrations up to 50 mg L −1. Maximum levels of 50% and 60% soil removal were achieved using PAA (50 mg L −1) and PAC (50 mg L −1), respectively, after 30 min from a 5 g L −1 suspension containing TX-100 (5 g L −1). The soil coagulation process was found to decrease with an increase in the pH of the suspension, and maximum coagulation was achieved with an acidic pH.

Purification and Characterization of Camel (Camelus dromedarius) Milk Amylase

Skimmed camel milk contains 59,900 U/L amylase, which is 39,363 times less than serum and plasma amylase. Camel milk β-amylase was purified as a 61 KDa band using DEAE-Sepharose and Sephadex G-100 and yielded 561 U/mg. The optimum working pH, Km and temperature were 7.0, 13.6 mg/Lstarch, 30–40°C, respectively. The enzyme has been shown higher affinity toward amylose and soluble starch than glycogen, amylopectin, dextrin, or pullulan. Magnesium chloride, CaCl2 and NaCl activated the amylase, while EDTA and EGTA decreased its activity. While its activity was increased in the presence of Triton X-100 and Triton X-114. Phenylmethanesulfonyl fluoride did not show any effect on enzyme activity. However, the enzyme activity was inhibited by urea, SDS, DTNB, iodoacetamide, N-ethylmalimide, aprotinin, and trypsin inhibitor. It worked on starch to yield a maltose. Scanning electron microscope images demonstrated a nano-degrading ability on starch granules from various sources (potato, corn, cassava, and rice).

A novel alkaline and low-temperature lipase ofBurkholderia cepacia isolated from Bohai in China for detergent formulation

The bacterial strain LP08 was isolated from soil collected from bay of Bohai, China. The sequence of 16S rDNA of strain LP08 showed 99% homology toBurkholderia cepacia. The lipase fromBurkholderia cepacia LP08 was purified by ammonium sulphate precipitation, ion exchange chromatography and Sephadex G-75 chromatography. The characterization of the lipase exhibited maximum activity at 30 °C and pH 9.0. The lipase retained 63, 66, 74, and 95% of its maximum activity at 10, 15, 20 and 25 °C respectively. The lipase activity was promoted in the presence of commercial detergent, sodium cholate, sodium taurocholate, glycerine and NaCl, while was little inhibited in the presence of Triton X-100, Tween-20, Tween-80, SDS, saponin. The present lipase was highly stable towards oxidizing agents and was stable after 1 h at 25 °C in the presence of hydrogen peroxide, sodium hypochlorite and sodium perborate. The results suggest that the lipase fromBurkholderia cepacia LP08 showed good potential for application in the detergent formulation.

Discovery of novel Trypanosoma cruzi glyceraldehyde-3-phosphate dehydrogenase inhibitors

Based on its essential role in the life cycle of Trypanosoma cruzi, the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH) has been considered a promising target for the development of novel chemotherapeutic agents for the treatment of Chagas’ disease. In the course of our research program to discover novel inhibitors of this trypanosomatid enzyme, we have explored a combination of structure and ligand-based virtual screening techniques as a complementary approach to a biochemical screening of natural products using a standard biochemical assay. Seven natural products, including anacardic acids, flavonoid derivatives, and one glucosylxanthone were identified as novel inhibitors of T. cruzi GAPDH. Promiscuous inhibition induced by nonspecific aggregation has been discarded as specific inhibition was not reversed or affected in all cases in the presence of Triton X-100, demonstrating the ability of the assay to find authentic inhibitors of the enzyme. The structural diversity of this series of promising natural products is of special interest in drug design, and should therefore be useful in future medicinal chemistry efforts aimed at the development of new GAPDH inhibitors having increased potency.

Effects of nonionic surfactant Triton X-100 on the laccase-catalyzed conversion of bisphenol A

The laccase-catalyzed conversion of bisphenol A (BPA) in aqueous solutions was studied in the absence and presence of nonionic surfactant Triton X-100. It was found that the addition of Triton X-100 into the reaction system increased the conversion of BPA, especially near the critical micelle concentration of Triton X-100. Also it was found that the stability of laccase was greatly improved in the presence of TritonX-100. Studies on the endogenous fluorescence emission of laccase indicated that there existed an interaction between Triton X-100 and laccase, which was beneficial to folding and stabilizating of laccase. The binding of Triton X-100 to the laccase surface also mitigated the inactivation effect caused by the free radicals and polymerization products. Under otherwise identical conditions, a lower dosage of laccase was needed for the higher conversion of BPA in the presence of Triton X-100.

Flexible Thin Films of Single-Walled Carbon Nanotubes Deposited on Plastic Substrates

In the present study, an experimental procedure used to produce thin films of single-walled carbon nanotubes is described. The method was used to prepare solid-state thin films of single walled carbon nanotubes (SWNTs) for various types of studies, such as scanning electron microscopy (SEM) and electrical resistance characterization. In particular, a series of experiments were carried out and, for the first time, a simple and reliable method for removing surfactant (Triton X-100) was described. The scanning electron microscopy studies showed that the SWNTs were shortened after the sonication process used to prepare the SWNT aqueous dispersion in the presence of Triton X-100.

Preparation and characteristics of composites based on polypropylene and ultradispersed calcium carbonate

Feasibility studies directed at the parallel increase in the elastic modulus and impact toughness of polypropylene via introduction of ultradispersed CaCO3 particles with sizes of 100 (Socal U1S2) and 60 nm (Socal 312V) have been performed. The effects of the content and sizes of CaCO3 particles and the nature of a surfactant on the character of distribution of particles, the thermophysical characteristics of the polymer matrix, and the mechanical characteristics and heat resistance of the nanocomposites are analyzed. Microscopic studies reveal that nanoparticles show a tendency toward structuring. DSC studies have proved the nucleating action of ultrafine particles during the crystallization of PP. For the composites containing 15 vol % of Socal 312V CaCO3 nanoparticles, the increase in the tensile elastic modulus achieves its maximum; depending on the nature of the surfactant, the reinforcing effect increases by 70-40%. As compared to the initial PP, the presence of ultrafine particles in the composites prevents a decrease in the storage modulus of PP with increasing temperature from 0 to 50°C; as a result, the reinforcing effect increases from 30-40% at temperatures below the glass transition temperature to 40–75% at 50°C. For the nanocomposites with U1S2 in the presence of Triton X-100 or fluorinated alcohol telomer, the impact toughness increases over the entire filler content interval; when the filler concentration is 15 vol %, the impact toughness of nanocomposites is higher than that of the initial PP by factors of 3 and 4.5, respectively. It has been found that nanocomposites containing 5 vol % CaCO3 nanoparticles show the effect of thermal stabilization, which comes up to about 50°C.

Preconcentration and Speciation of Sb(III) and Sb(V) in Water Samples and Blood Serum after Cloud Point Extraction Using Chemometric Tools for Optimization

A new Sb(III) and Sb(V) preconcentration and speciation method, optimized by multivariate design using cloud point extraction (CPE) with determination by graphite furnace atomic absorption spectrometry, is described. It is based on the formation of Sb(III) complexes with ammonium O, O- diethyl dithiophosphate (DDTP) in acid medium in the presence of Triton X-114. The Sb(V) is determined after quantitative reduction with L-cysteine, and its concentration is calculated by subtracting Sb(III) from the total antimony amount. The method provides a linear calibration range from 0.25 to 16.0 µg L−1 (r > 0.994) and limits of detection and quantification of 0.08 µg L−1 and 0.25 µg L−1, respectively. A high preconcentration factor was found to be 229-fold by preconcentrating 12.0 mL of sample. The proposed method was successfully applied for the preconcentration and speciation of Sb(III) and Sb(V) in water samples and blood serum, where satisfactory recovery values were obtained, thus attesting to the feasibility of the method.

Immobilization in the presence of Triton X-100: modifications in activity and thermostability of Geobacillus thermoleovorans CCR11 lipase

A partially purified lipase produced by the thermophile Geobacillus thermoleovorans CCR11 was immobilized by adsorption on porous polypropylene (Accurel EP-100) in the presence and absence of 0.1% Triton X-100. Lipase production was induced in a 2.5% high oleic safflower oil medium and the enzyme was partially purified by diafiltration (co. 500,000 Da). Immobilization conditions were established at 25 degrees C, pH 6, and a protein concentration of 0.9 mg/mL in the presence and absence of 0.1% Triton X-100. Immobilization increased enzyme thermostability but there was no change in neither the optimum pH nor in pH resistance irrelevant to the presence of the detergent during immobilization. Immobilization with or without Triton X-100 allowed the reuse of the lipase preparation for 11 and 8 cycles, respectively. There was a significant difference between residual activity of immobilized and soluble enzyme after 36 days of storage at 4 degrees C (P < 0.05). With respect to chain length specificity, the immobilized lipase showed less activity over short chain esters than the soluble lipase. The immobilized lipase showed good resistance to desorption with phosphate buffer and NaCl; minor loses with detergents were observed (less than 50% with Triton X-100 and Tween-80), but activity was completely lost with SDS. Immobilization of G. thermoleovorans CCR11 lipase in porous polypropylene is a simple and easy method to obtain a biocatalyst with increased stability, improved performance, with the possibility for re-use, and therefore an interesting potential use in commercial conditions.

Successive Fusion of Vesicles Aggregated by DNA Duplex Formation in the Presence of Triton X-100

Abstract Two kinds of large vesicles (average diameter: ca. 0.2 μm) bearing complementary DNA strands aggregated to form densely packed clusters. Addition of Triton X-100 (1.2 mM) as a fusogenic reagent to an aqueous suspension of the vesicle-clusters induced successive fusion of vesicles, leading to a giant multilamellar vesicle-like sphere with a diameter of ca. 3 μm.

Activation Mechanisms for Pseudomonas Species Lipase by Cardiovascular Drugs in Vitro

AbstractThe goal of this work was to determine the reaction mechanism for Pseudomonas species lipase activation by cardiovascular drugs such as lovastatin, simvastatin, amlodipine besylate, nifedipine, and hydralazine hydrochloride based on the results from enzyme kinetics. These drugs are the essential activators of Pseudomonas species lipase in the presence of triton‐X 100 or taurochloate in vitro. Moreover, QSAR studies show that the pKA values are correlated with the molecular weights of these drugs.

Successive determination of urinary protein and glucose using spectrophotometric sequential injection method

A new sequential injection (SI) system with spectrophotometric detections has been developed for successive determination of protein and glucose. The protein assay is based on ion-association of protein with tetrabromophenolphthalein ethyl ester (TBPE) in the presence of Triton X-100 at pH 3.2. The blue product is monitored for absorbance at 607 nm. For glucose, hydrogen peroxide, generated by the oxidation of glucose in the presence of glucose oxidase immobilized on glass beads packed in a minicolumn, is monitored using iron-catalyzed oxidation reaction of p-anisidine to form a red colored product (520 nm). The SI procedure takes advantage in performing the protein assay during the incubation period for glucose oxidation. Linear ranges were up to 10 mg dL −1 human serum albumin (HSA) with a limit of detection (LOD) (3 σ) of 0.3 mg dL −1, and up to 12.5 mg dL −1 glucose with LOD of 0.08 mg dL −1. R.S.D.s ( n = 11) were 2.7% and 2.5% (for 1 mg dL −1 and 5 mg dL −1 HSA) and 1.4% (9 mg dL −1 glucose). Sample throughput for the whole assay of both protein and glucose is 6 h −1. The automated system has been demonstrated for the successive assay of protein and glucose in urine samples taken from diabetic disease patients, with good agreement with the other methods. This developed SI system is an alternative automation for screening for diabetic diagnosis.

Electrostatic effect of surfactant molecules on bacteriochlorophyll a and carotenoid binding sites in the LH1 complex isolated from Rhodospirillum rubrum S1 probed by Stark spectroscopy

The LH1 complexes were isolated from the purple photosynthetic bacterium Rhodospirillum rubrum strain S1. They were initially solubilized using LDAO and then purified in the presence of Triton X-100. The purified complexes were then either used directly or following an exchange into LDAO. Stark spectroscopy was applied to probe the electrostatic field around the bacteriochlorophyll a (BChl a) and carotenoid binding sites in the LH1 complexes surrounded by these two different surfactant molecules. Polarizabilty change (deltaalpha)) and dipole moment change (deltamicrom) upon photoexcitation were determined for the BChl a Q(y) band. Both of these parameters show smaller values in the presence of LDAO than in Triton X-100. This indicates that polar detergent molecules, like LDAO, affect the electrostatic environment around BChl a, and modify the nonlinear optical parameters (deltaalpha and deltamicrom values). The electrostatic field around the BChl a binding site, which is generated by the presence of LDAO, was determined to be |E ( L )| = approximately 3.9 x 10(5) [V/cm]. Interestingly, this kind of electrostatic effect was not observed for the carotenoid-binding site. The present study demonstrates a unique electrostatic interaction between the polar detergent molecules surrounding the LH1 complex and the Q(y) absorption band of BChl a that is bound to the LH1 complex.

Size Controlled ZnO Nanoparticles Prepared by Water-in-Oil Microemulsion

ZnO nanoparticles were carried out by Microemulsion method in the presence of TritonX-100 (poly oxyethylene tert-octylphenyl ether) as a surfactant. X-100/n-hextnol/cyclohexane/ waterW/O microemulsion system was also determined. Zinc chloride (ZnCl2·2H2O) and ammonia (NH3·H2O) were used as raw materials. The results indicated that the formation of ZnO nanoparticles was confirmed, using X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The results showed that the nanoparticle was exactly ZnO with wurtzite type crystalline structure and the size of nanoparticles is strongly affected by the ratio of water to surfactant(R). With the R value increase, the particles size became larger.

Highly Selective and Sensitive Spectrophotometric Determination of Trace Amounts of Silver Ion in Surfactant Media Using 2‐Mercaptobenzoxazole

A simple and accurate spectrophotometric method for determination of trace amounts of silver ion in tap and wastewater solution and photographic solutions has been described. The spectrophotometric determination of silver ion using 2-mercaptobenzoxazole (MBO) in the presence of Triton X-100 as nonionic surfactant has been carried out. The Beer's law is obeyed over the concentration range of 0.1-9.0 microg mL(-1) of Ag+ ion with the detection limits of 1.6 ng mL(-1). The influence of type and amount of surfactant, pH, complexation time and amount of ligand on sensitivity of method were optimized. Finally the repeatability, accuracy and the effect of interfering ions on the determination of silver ion were evaluated. There is a good agreement between results of proposed method and atomic absorption spectrometry.

Effect of nonionic surfactants on the oxidation of carbaryl by anodic Fenton treatment

As a potentially promising technology, anodic Fenton treatment (AFT) has been shown to be very successful in pesticide removal. However, the influence of other constituents in the pesticide formulation, such as nonionic surfactants, has not been addressed. In this study, the effect of Triton X (TX) on the degradation kinetics and pathways of carbaryl undergoing AFT was investigated in an effort to facilitate its practical application. The presence of Triton X-100 was found to slow down the carbaryl degradation rate. This result can be attributed to the consumption of hydroxyl radicals ( OH) by surfactants and the formation of a carbaryl⋯TX⋯Fe 3+ complex, resulting in the unavailability of carbaryl to OH attack. The modified AFT kinetic model previously developed in this laboratory shows an excellent fit to the carbaryl degradation profile ( R 2>0.998), supporting the formation of a carbaryl⋯TX⋯Fe 3+ complex. The carbaryl degradation rate decreased as Triton X-100 concentration increased from 20 to 1000 mg L −1. Both OH consumption by surfactants and complex formation are responsible for the degradation rate reduction below the critical micelle concentration (CMC), whereas the complex and micelle formation becomes a more dominant factor above the CMC. The effect of ethylene oxide (EO) numbers of a given nonionic surfactant mainly lies in the consumption of hydroxyl radicals, which increases with the length of the EO chain, but does not significantly affect the formation of the carbaryl⋯TX⋯Fe 3+ complex. Based on the GC–MS and LC–ESI–MS results, no evidence was found that the carbaryl degradation pathway was affected. Carbaryl was typically oxidized to 1-naphthol and 1,4-naphthoquinone similar to what is observed in the absence of surfactants. Triton X-100 was degraded via the breakdown of EO chains and ω-oxidation of the terminal methyl group, which resulted in the production of a series of ethoxylate oligomers.

Factors Affecting the Adsorption of Bacteriocins to Lactobacillus sakei and Enterococcus sp.

Bacteriocins bacJW3BZ and bacJW6BZ produced by Lactobacillus plantarum, and bacJW11BZ and bacJW15BZ produced by Lactobacillus fermentum, inhibit Gram-positive and Gram-negative bacteria. Treatment of Enterococcus sp. HKLHS and Lactobacillus sakei DSM 20017 with these bacteriocins deformed the cells and resulted in DNA and beta-galactosidase leakage. The bacteriocins adsorbed to sensitive and resistant strains. Optimal adsorption of bacJW3BZ and bacJW6BZ to Enterococcus sp. HKLHS was recorded at pH 10.0, whereas adsorption of bacJW11BZ and bacJW15BZ was favored at pH 4.0-8.0 and 2.0-4.0, respectively. Adsorption to L. sakei DSM 20017 was less influenced by pH. Incubation temperature had a major influence on the adsorption of bacJW6BZ and bacJW11BZ to sensitive cells, with better results recorded below 30 degrees C. Although variable results were recorded for bacJW3BZ and bacJW15BZ, optimal adsorption occurred between 37 and 60 degrees C. Variable levels of adsorption were recorded in the presence of inorganic salts and solvents, and this seems to be species-specific. Maximal adsorption (100%) was recorded for bacJW3BZ and bacJW15BZ to L. sakei DSM 20017 in the presence of most inorganic salts and solvents tested. Maximal adsorption of bacJW6BZ to Enterococcus sp. HKLHS (50%) was recorded in the presence of Triton X-114 and little (17%) or no adsorption in the presence of other reagents.