Retention of prominin in microvilli reveals distinct cholesterol-based lipid micro-domains in the apical plasma membrane.

PubMed

Röper, K; Corbeil, D; Huttner, W B

2000-09-01

Membrane cholesterol-sphingolipid 'rafts', which are characterized by their insolubility in the non-ionic detergent Triton X-100 in the cold, have been implicated in the sorting of certain membrane proteins, such as placental alkaline phosphatase (PLAP), to the apical plasma membrane domain of epithelial cells. Here we show that prominin, an apically sorted pentaspan membrane protein, becomes associated in the trans-Golgi network with a lipid raft that is soluble in Triton X-100 but insoluble in another non-ionic detergent, Lubrol WX. At the cell surface, prominin remains insoluble in Lubrol WX and is selectively associated with microvilli, being largely segregated from the membrane subdomains containing PLAP. Cholesterol depletion results in the loss of prominin's microvillus-specific localization but does not lead to its complete intermixing with PLAP. We propose the coexistence within a membrane domain, such as the apical plasma membrane, of different cholesterol-based lipid rafts, which underlie the generation and maintenance of membrane subdomains.

Mobilization of arsenic from contaminated sediment by anionic and nonionic surfactants.

PubMed

Liang, Chuan; Peng, Xianjia

2017-06-01

The increasing manufacture of surfactants and their wide application in industry, agriculture and household detergents have resulted in large amounts of surfactant residuals being discharged into water and distributed into sediment. Surfactants have the potential to enhance arsenic mobility, leading to risks to the environment and even human beings. In this study, batch and column experiments were conducted to investigate arsenic mobilization from contaminated sediment by the commercial anionic surfactants sodium dodecylbenzenesulfonate (SDBS), sodium dodecyl sulfate (SDS), sodium laureth sulfate (AES) and nonionic surfactants phenyl-polyethylene glycol (Triton X-100) and polyethylene glycol sorbitan monooleate (Tween-80). The ability of surfactants to mobilize arsenic followed the order AES>SDBS>SDS≈Triton X-100>Tween 80. Arsenic mobilization by AES and Triton X-100 increased greatly with the increase of surfactant concentration and pH, while arsenic release by SDBS, SDS and Tween-80 slightly increased. The divalent ion Ca 2+ caused greater reduction of arsenic mobilization than Na + . Sequential extraction experiments showed that the main fraction of arsenic mobilized was the specifically adsorbed fraction. Solid phase extraction showed that arsenate (As(V)) was the main species mobilized by surfactants, accounting for 65.05%-77.68% of the total mobilized arsenic. The mobilization of arsenic was positively correlated with the mobilization of iron species. The main fraction of mobilized arsenic was the dissolved fraction, accounting for 70% of total mobilized arsenic. Copyright © 2016. Published by Elsevier B.V.

Comparative lipidomics and proteomics analysis of platelet lipid rafts using different detergents.

PubMed

Rabani, Vahideh; Davani, Siamak; Gambert-Nicot, Ségolène; Meneveau, Nicolas; Montange, Damien

2016-11-01

Lipid rafts play a pivotal role in physiological functions of platelets. Their isolation using nonionic mild detergents is considered as the gold standard method, but there is no consensual detergent for lipid raft studies. We aimed to investigate which detergent is the most suitable for lipid raft isolation from platelet membrane, based on lipidomics and proteomics analysis. Platelets were obtained from healthy donors. Twelve sucrose fractions were extracted by three different detergents, namely Brij 35, Lubrol WX, and Triton X100, at 0.05% and 1%. After lipidomics analysis and determination of fractions enriched in cholesterol (Ch) and sphingomyelin (SM), proteomics analysis was performed. Lipid rafts were mainly observed in 1-4 fractions, and non-rafts were distributed on 5-12 fractions. Considering the concentration of Ch and SM, Lubrol WX 1% and Triton X100 1% were more suitable detergents as they were able to isolate lipid raft fractions that were more enriched than non-raft fractions. By proteomics analysis, overall, 822 proteins were identified in platelet membrane. Lipid raft fractions isolated with Lubrol WX 0.05% and Triton X100 1% contained mainly plasma membrane proteins. However, only Lubrol WX 0.05 and 1% and Triton X100 1% were able to extract non-denaturing proteins with more than 10 transmembrane domains. Our results suggest that Triton X100 1% is the most suitable detergent for global lipid and protein studies on platelet plasma membrane. However, the detergent should be adapted if investigation of an association between specific proteins and lipid rafts is planned.

Non-ionic detergent Triton X-114 Based vortex- synchronized matrix solid-phase dispersion method for the simultaneous determination of six compounds with various polarities from Forsythiae Fructus by ultra high-performance liquid chromatography.

PubMed

Du, Kunze; Li, Jin; Tian, Fei; Chang, Yan-Xu

2018-02-20

A simple nonionic detergent - based vortex- synchronized matrix solid-phase dispersion (ND-VSMSPD) method was developed to extract bioactive compounds in Forsythiae Fructus coupled with ultra high-performance liquid chromatography (UHPLC). Nonionic detergent Triton 114 was firstly used as a green elution reagent in vortex- synchronized MSPD procedure. The optimum parameters were investigated to attain the best results, including Florisil as sorbent, 2mL 10% (v/v) nonionic detergent Triton X-114 as the elution reagent, 1:1 of sample/sorbent ratio, grinding for 3min, and whirling for 2min. The recoveries of the six compounds in Forsythiae Fructus were in the range of 95-104% (RSD <4.6%) and the method displayed a good linearity within the range of 0.08-20μgmL -1 for caffeic acid, 0.6-150μgmL -1 for forsythoside A, 0.4-100μgmL -1 phillyrin, 0.2-50μgmL -1 for quercetin, isorhamnetin and arctigenin (r≥0.999). It was proved that the extraction yields of almost all compounds attained by the established vortex- synchronized MSPD, which required lower sample, reagent and time, were higher than the normal MSPD and the traditional ultrasonic-assisted extraction. Consequently, this developed vortex- synchronized MSPD coupled with simple UHPLC method could be efficiently applies to extract and analyze the target compounds in real Forsythiae Fructus samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Affinity Chromatography in Nonionic Detergent Solutions

NASA Astrophysics Data System (ADS)

Robinson, Jack B.; Strottmann, James M.; Wick, Donald G.; Stellwagen, Earle

1980-10-01

Anionic dye affinity chromatography is commonly unproductive in the presence of nonionic detergents used to extract particulate proteins. Using lactate dehydrogenase as a model protein, Cibacron blue F3GA as a model dye, and Triton X-100 as a model detergent, we find that the dye is encapsulated in nonionic detergent micelles, rendering the dye incapable of ligation with the enzyme. However, the dye can be liberated from the micelles without altering the nonionic detergent concentration by addition of an anionic detergent, such as deoxycholate or sodium dodecyl sulfate, forming mixed anionic/nonionic micelles that displace the anionic dye. Encapsulation of the anionic detergents prevents their activity as protein denaturants. These observations have been successfully translated to the dye affinity chromatography of a detergent extract of brain particulate cyclic nucleotide phosphodiesterase.

The selective solubilization of different murine splenocyte membrane fractions with lubrol WX and triton X-100 distinguishes two forms of Ia antigens. A cell surface (alpha, beta) and an intracellular (alpha, Ii, beta).

PubMed

Moosic, J P; Sung, E; Nilson, A; Jones, P P; McKean, D J

1982-08-25

The selective solubilization of different murine lymphocyte membrane compartments with several nonionic detergents was used to study the subcellular distribution of two distinct forms of lymphocyte cell recognition structures (Ia antigens). Ia antigens were isolated with a monoclonal anti-Ia immunoadsorbent from murine splenocytes that had been solubilized with four different nonionic detergents. Analyses of the immunoprecipitates indicated that Lubrol WX was selectively solubilizing a subpopulation of Ia consisting of mature highly glycosylated alpha and beta polypeptides which were not associated with Ii polypeptide. A second Ia subpopulation consisting of less glycosylated cytoplasmic precursor alpha and beta polypeptides associated with Ii polypeptide was immunoprecipitated from the Lubrol WX-insoluble material after solubilizing this material with Triton X-100. Comparable results were obtained when HLA-DR antigens were similarly isolated from cultured human lymphoblastoid cells. This selective solubilization phenomenon was not unique to Ia antigens. Only mature highly glycosylated H-2K molecules were immunoprecipitated from the Lubrol WX-soluble material while the less glycosylated precursor H-2K molecules were immunoprecipitated from the Triton X-100-solubilized Lubrol-insoluble material. These data directly demonstrate that the Ii polypeptide is exclusively associated with the intracellular Ia antigen cytoplasmic precursor molecules. These data also indicate that, under the conditions used in these experiments, Lubrol WX does not completely solubilize integral membrane proteins that have previously been shown to be associated with the rough endoplasmic reticulum.

Kinetic tetrazolium microtiter assay

NASA Technical Reports Server (NTRS)

Pierson, Duane L. (Inventor); Stowe, Raymond P. (Inventor); Koeing, David W. (Inventor)

1992-01-01

A method for conducting an in vitro cell assay using a tetrazolium indicator is disclosed. The indicator includes a nonionic detergent which solubilizes a tetrazolium reduction product in vitro and has low toxicity for the cells. The incubation of test cells in the presence of zolium bromide and octoxynol (TRITON X-100) permits kinetics of the cell metabolism to be determined.

Effects of surfactant and salt species in reverse micellar forward extraction efficiency of isoflavones with enriched protein from soy flour.

PubMed

Zhao, Xiaoyan; Wei, Zhiyi; Du, Fangling; Zhu, Junqing

2010-11-01

Suitability of reverse micelles of anionic surfactant sodium bis(2-ethyl hexyl) sulfosuccinate (AOT) and sodium dodecyl sulfate (SDS), cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) and nonionic surfactant polyoxyethylene p-t-octylphenol (TritonX-100) in organic solvent isooctane for extraction of soy isoflavone-enriching proteins was investigated. The results showed that the order of combined isoflavone contents was SDS>CTAB>Triton X-100>AOT, while the order of protein recovery was SDS>AOT>TritonX-100>CTAB. As compared with ACN-HCl extraction, the total amount of isoflavones was lower than reverse micellar extraction. Ion strength was one of the important conditions to control extraction of isoflavone-enriching proteins with AOT reversed micelles. For the six salt systems, KNO(3), KCl, MgCl(2), CaCl(2), NaCl, and Na(2)SO(4), extracted fraction of isoflavone-enriching proteins was measured. Salt solutions greatly influenced the extraction efficiency of isoflavones in an order of KNO(3)>MgCl(2)>CaCl(2)>KCl>NaCl>Na(2)SO(4), while protein in an order of MgCl(2)>CaCl(2)>NaCl>KNO(3)>Na(2)SO(4)>KCl.

Releasing intracellular product to prepare whole cell biocatalyst for biosynthesis of Monascus pigments in water-edible oil two-phase system.

PubMed

Hu, Minglue; Zhang, Xuehong; Wang, Zhilong

2016-11-01

Selective releasing intracellular product in Triton X-100 micelle aqueous solution to prepare whole cell biocatalyst is a novel strategy for biosynthesis of Monascus pigments, in which cell suspension culture exhibits some advantages comparing with the corresponding growing cell submerged culture. In the present work, the nonionic surfactant Triton X-100 was successfully replaced by edible plant oils for releasing intracellular Monascus pigments. High concentration of Monascus pigments (with absorbance nearly 710 AU at 470 nm in the oil phase, normalized to the aqueous phase volume approximately 142 AU) was achieved by cell suspension culture in peanut oil-water two-phase system. Furthermore, the utilization of edible oil as extractant also fulfills the demand for application of Monascus pigments as natural food colorant.

Lipid Bilayers in the Gel Phase Become Saturated by Triton X-100 at Lower Surfactant Concentrations Than Those in the Fluid Phase

PubMed Central

Ahyayauch, Hasna; Collado, M. Isabel; Alonso, Alicia; Goñi, Felix M.

2012-01-01

It has been repeatedly observed that lipid bilayers in the gel phase are solubilized by lower concentrations of Triton X-100, at least within certain temperature ranges, or other nonionic detergents than bilayers in the fluid phase. In a previous study, we showed that detergent partition coefficients into the lipid bilayer were the same for the gel and the fluid phases. In this contribution, turbidity, calorimetry, and 31P-NMR concur in showing that bilayers in the gel state (at least down to 13–20°C below the gel-fluid transition temperature) become saturated with detergent at lower detergent concentrations than those in the fluid state, irrespective of temperature. The different saturation may explain the observed differences in solubilization. PMID:22713566

Water solubility enhancements of DDT and trichlorobenzene by some surfactants below and above the critical micelle concentration

USGS Publications Warehouse

Kile, D.E.; Chiou, C.T.

1989-01-01

Water solubility enhancements of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT) and 1,2,3-trichlorobenzene (TCB) by aqueous surfactants below and above their critical micelle concentrations (CMCs) have been studied at room temperature with the following surfactants: Triton X-100, Triton X-114, Triton X-405, Brij 35, sodium dodecyl sulfate, and cetyltrimethylammonium bromide. While the solubilities of DDT and TCB are greatly enhanced by all surfactants above the measured CMC, DDT also exhibits significant solubility enhancements below the CMC of the molecularly nonhomogeneous surfactants (the Triton series and Brij 35). The plot of the apparent DDT solubility against the concentration of Triton and Brij surfactants shows an uprising curve below the nominal CMC, which is attributed to the successive micellization of the heterogeneous monomer species. Above the CMC, the enhancement effect with the nonionic surfactants is closely proportional to the nonpolar chain content of the surfactant, whereas the effect with the ionic surfactants is less accountable in terms of their nonpolar chain contents. The solubilization power of a micelle relative to a bulk solvent is evaluated by a comparison of the observed micelle-water and solvent-water partition coefficients.

Solubilization of glycoproteins of envelope viruses by detergents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berezin, V.E.; Zaides, V.M.; Artamsnov, A.F.

1986-11-20

The action of a number of known ionic and nonionic detergents, as well as the new nonionic detergent MESK, on envelope viruses was investigated. It was shown that the nonionic detergents MESK, Triton X-100, and octyl-..beta..-D-glucopyranoside selectively solubilize the outer glycoproteins of the virus particles. The nonionic detergent MESK has the mildest action. Using MESK, purified glycoproteins of influenza, parainfluenza, Venezuelan equine encephalomyelitis, vesicular stomatitis, rabies, and herpes viruses were obtained. The procedure for obtaining glycoproteins includes incubation of the virus suspension with the detergent MESK, removal of subvirus structures by centrifuging, and purification of glycoproteins from detergents by dialysis.more » Isolated glycoproteins retain a native structure and biological activity and possess high immunogenicity. The detergent MESK is promising for laboratory tests and with respect to the production of subunit vaccines.« less

Comparative study of the interaction of CHAPS and Triton X-100 with the erythrocyte membrane.

PubMed

Rodi, P M; Bocco Gianello, M D; Corregido, M C; Gennaro, A M

2014-03-01

The zwitterionic detergent CHAPS, a derivative of the bile salts, is widely used in membrane protein solubilization. It is a "facial" detergent, having a hydrophilic side and a hydrophobic back. The objective of this work is to characterize the interaction of CHAPS with a cell membrane. To this aim, erythrocytes were incubated with a wide range of detergent concentrations in order to determine CHAPS partition behavior, and its effects on membrane lipid order, hemolytic effects, and the solubilization of membrane phospholipids and cholesterol. The results were compared with those obtained with the nonionic detergent Triton X-100. It was found that CHAPS has a low affinity for the erythrocyte membrane (partition coefficient K=0.06mM(-1)), and at sub-hemolytic concentrations it causes little effect on membrane lipid order. CHAPS hemolysis and phospholipid solubilization are closely correlated. On the other side, binding of Triton X-100 disorders the membrane at all levels, and has independent mechanisms for hemolysis and solubilization. Differential behavior was observed in the solubilization of phospholipids and cholesterol. Thus, the detergent resistant membranes (DRM) obtained with the two detergents will have different composition. The behaviors of the two detergents are related to the differences in their molecular structures, suggesting that CHAPS does not penetrate the lipid bilayer but binds in a flat position on the erythrocyte surface, both in intact and cholesterol depleted erythrocytes. A relevant result for Triton X-100 is that hemolysis is not directly correlated with the solubilization of membrane lipids, as it is usually assumed. Copyright © 2013 Elsevier B.V. All rights reserved.

Study of the influence of different organic pollutants on Cu accumulation by Halimione portulacoides

NASA Astrophysics Data System (ADS)

Almeida, C. Marisa R.; Claúdia Dias, A.; Mucha, Ana P.; Bordalo, A. A.; Vasconcelos, M. Teresa S. D.

2009-12-01

The influence of each of four organic pollutants selected from among those commonly found in coastal areas, 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), monobutyltin (MBT), Triton X-100 and polycyclic aromatic hydrocarbons (PAHs), on Cu accumulation by Halimione portulacoides was investigated. Experiments were carried out in a laboratory setting, either in hydroponics (sediment elutriate) or in a salt marsh sediment ( Cávado River, NW Portugal) soaked in elutriate. Groups of H. portulacoides were exposed to media for 6 days spiked with 10 mg/L Cu(II) and with one of the selected pollutants, at an environmentally realistic concentration. DDE and MBT did not cause any major change on Cu accumulation by H. portulacoides, whereas PAHs slightly increased accumulation only in hydroponics i.e. in the absence of sediment. On the other hand, the non-ionic surfactant Triton X-100 markedly favoured Cu accumulation on plant roots both in the presence and absence of sediment. The addition of DDE, MBT and Triton X-100 also favoured Cu solubility from sediments. Therefore, the simultaneous presence of pollutants from different nature (inorganic and organic) in the estuarine environment may result in a composition of water column, pore water, sediment or biota different of that expected considering the effect of each individual pollutant.

Relationship between sol-gel conditions and enzyme stability: a case study with β-galactosidase/silica biocatalyst for whey hydrolysis.

PubMed

Escobar, Sindy; Bernal, Claudia; Mesa, Monica

2015-01-01

The sol-gel process has been very useful for preparing active and stable biocatalysts, with the possibility of being reused. Especially those based on silica are well known. However, the study of the enzyme behavior during this process is not well understood until now and more, if the surfactant is involved in the synthesis mixture. This work is devoted to the encapsulation of β-galactosidase from Bacillus circulans in silica by sol-gel process, assisted by non-ionic Triton X-100 surfactant. The correlation between enzyme activity results for the β-galactosidase in three different environments (soluble in buffered aqueous reference solution, in the silica sol, and entrapment on the silica matrix) explains the enzyme behavior under stress conditions offered by the silica sol composition and gelation conditions. A stable β-galactosidase/silica biocatalyst is obtained using sodium silicate, which is a cheap source of silica, in the presence of non-ionic Triton X-100, which avoids the enzyme deactivation, even at 40 °C. The obtained biocatalyst is used in the whey hydrolysis for obtaining high value products from this waste. The preservation of the enzyme stability, which is one of the most important challenges on the enzyme immobilization through the silica sol-gel, is achieved in this study.

A mechanism of basal spacing reduction in sodium smectitic clay materials in contact with DNAPL wastes.

PubMed

Ayral-Cinar, Derya; Otero-Diaz, Margarita; Demond, Avery H

2016-09-01

There has been concern regarding the possible attack of clays in aquitards, slurry walls and landfill liners by dense nonaqueous phase liquid (DNAPL) wastes, resulting in cracking. Despite the fact that a reduction in basal spacing in sodium smectitic clay materials has been linked to cracking, no plausible mechanism by which this reduction occurs in contact with waste DNAPLs has been formulated. To elucidate a mechanism, screening studies were conducted that showed that the combination of an anionic surfactant (AOT), a nonionic surfactant (TritonX-100) and a chlorinated solvent, tetrachloroethylene (PCE), could replicate the basal spacing reduction and cracking behavior of water-saturated bentonite caused by two waste DNAPLs obtained from the field. FTIR measurements of this system showed a displacement of the HOH bending band of water symptomatic of desiccation. Sorption measurements showed that the uptake of AOT by bentonite increased eight fold in the presence of TritonX-100 and PCE. The evidence presented here supports a mechanism of syneresis, involving the extraction of water from the interlayer space of the clay through the synergistic sorption of a nonionic and anionic surfactant mixture. It is speculated that the solvation of water in reverse micellar aggregates is the process driving the syneresis. Copyright © 2016. Published by Elsevier Ltd.

Congo red adsorption from aqueous solutions by using chitosan hydrogel beads impregnated with nonionic or anionic surfactant.

PubMed

Chatterjee, Sudipta; Lee, Dae S; Lee, Min W; Woo, Seung H

2009-09-01

The adsorption performance of CS beads impregnated with triton X-100 (TX-100) as a nonionic surfactant and sodium dodecyl sulfate (SDS) as an anionic surfactant was investigated for the removal of anionic dye (congo red) from aqueous solution. While the adsorption capacity of CS/TX-100 beads was enhanced at all concentrations of TX-100 (0.005-0.1%), the increase in the concentration of SDS above 0.01% in the CS/SDS beads gradually reduced the adsorption capacity of the beads. Equilibrium adsorption isotherm data indicated a good fit to the Sips isotherm model and a heterogeneous adsorption process. The Sips maximum adsorption capacity in dry weight of the CS/TX-100 beads was 378.79 mg/g and 318.47 mg/g for the CS/SDS beads, higher than the 223.25mg/g of the CS beads. Modification of CS beads by impregnation with nonionic surfactant, or even anionic surfactant, at low concentrations is a possible way to enhance adsorption of anionic dye.

Contrasting effects of a nonionic surfactant on the biotransformation of polycyclic aromatic hydrocarbons to cis-dihydrodiols by soil bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, C.C.R.; Boyd, D.R.; Hempenstall, F.

The biotransformation of the polycyclic aromatic hydrocarbons (PAHs) naphthalene and phenanthrene was investigated by using two dioxygenase-expressing bacteria, Pseudomonas sp. strain 9816/11 and Sphingomonas yanoikuyae B8/36, under conditions which facilitate mass-transfer limited substrate oxidation. Both of these strains are mutants that accumulate cis-dihydrodiol metabolites under the reaction conditions used. The effects of the nonpolar solvent 2,2,4,4,6,8,8-heptamethylnonane (HMN) and the nonionic surfactant Triton X-100 on the rate of accumulation of these metabolites were determined. HMN increased the rate of accumulation of metabolites for both microorganisms, with both substrates. The enhancement effect was most noticeable with phenanthrene, which has a lower aqueousmore » solubility than naphthalene. Triton X-100 increased the rate of oxidation of the PAHs with strain 9816/11 with the effect being most noticeable when phenanthrene was used as a substrate. However, the surfactant inhibited the biotransformation of both naphthalene and phenanthrene with strain B8/36 under the same conditions. The observation that a nonionic surfactant could have such contrasting effects on PAH oxidation by different bacteria, which are known to be important for the degradation of these compounds in the environment, may explain why previous research on the application of the surfactants to PAH bioremediation has yielded inconclusive results. The surfactant inhibited growth of the wild-type strain S. yanoikuyae B1 on aromatic compounds but did not inhibit B8/36 dioxygenase enzyme activity in vitro.« less

Large transient nonproton ion movements in purple membrane suspensions are abolished by solubilization in Triton X-100.

PubMed Central

Marinetti, T; Mauzerall, D

1986-01-01

Light-induced release/uptake of both protons and other ions cause transient changes in conductivity in suspensions of purple membrane (PM) fragments (Marinetti, Tim, and David Mauzerall, 1983, Proc. Natl. Acad. Sci. USA, 80:178-180). We find that the release/uptake of nonproton ions with quantum yield greater than 1 is observed at most pHs and ionic strengths. Only at both low pH and low ionic strength is the conductivity transient mostly due to protons. Our hypothesis is that during the photocycle, changes occur in the PM's dense surface charge distribution that result in changes in the number of counterions bound or condensed at the membrane surface. To test this, the PM structure was perturbed with the nonionic detergent Triton X-100. Immediately after addition, Triton does not abolish the nonproton ion movements; in fact at low detergent concentrations (0.02% vol/vol) the signal amplitudes increased considerably. However, when PM is completely solubilized into monomers in Triton, the conductivity transients are due to protons alone, though at lower quantum yield compared with native PM. These results suggest that changes in the surface charge distribution in native PM's photocycle could contribute to proton transfer between the aqueous phase and bR itself. PMID:3019444

Perstraction of Intracellular Pigments through Submerged Fermentation of Talaromyces spp. in a Surfactant Rich Media: A Novel Approach for Enhanced Pigment Recovery

PubMed Central

Oliveira, Jorge; Sousa-Gallagher, Maria; Méndez-Zavala, Alejandro; Montañez, Julio Cesar

2017-01-01

A high percentage of the pigments produced by Talaromyces spp. remains inside the cell, which could lead to a high product concentration inhibition. To overcome this issue an extractive fermentation process, perstraction, was suggested, which involves the extraction of the intracellular products out of the cell by using a two-phase system during the fermentation. The present work studied the effect of various surfactants on secretion of intracellular pigments produced by Talaromyces spp. in submerged fermentation. Surfactants used were: non-ionic surfactants (Tween 80, Span 20 and Triton X-100) and a polyethylene glycerol polymer 8000, at different concentrations (5, 20, 35 g/L). The highest extracellular pigment yield (16 OD500nm) was reached using Triton X-100 (35 g/L), which was 44% higher than the control (no surfactant added). The effect of addition time of the selected surfactant was further studied. The highest extracellular pigment concentration (22 OD500nm) was achieved when the surfactant was added at 120 h of fermentation. Kinetics of extracellular and intracellular pigments were examined. Total pigment at the end of the fermentation using Triton X-100 was 27.7% higher than the control, confirming that the use of surfactants partially alleviated the product inhibition during the pigment production culture. PMID:29371551

Influence of a nonionic surfactant (Triton X-100) on contaminant distribution between water and several soil solids

USGS Publications Warehouse

Lee, J.-F.; Liao, P.-M.; Kuo, C.-C.; Yang, H.-T.; Chiou, C.T.

2000-01-01

The influence of a nonionic surfactant (Triton X-100) on the contaminant distribution coefficients in solid-water mixtures was determined for a number of relatively nonpolar compounds (contaminants) on several natural solids. The studied compounds consisted of BTEX (benzene, toluene, ethylbenzene, and p-xylene) and chlorinated pesticides (lindane, ??-BHC, and heptachlor epoxide), which span several orders of magnitude in water solubility (S(W)); the solid samples comprised a bentonite, a peat, and two other soils, which cover a wide range of solid organic matter (SOM) content. The applied surfactant concentrations (X) ranged from below the (nominal) CMC to 2-3 times the CMC. For relatively water-soluble BTEX compounds, the distribution coefficients with surfactant (K*(d)) all exceeded those without surfactant (K(d)); the K*(d)/K(d) ratios increased with increasing S(w) from p-xylene to benzene on each solid at a given X, with increasing X for each compound on a solid, and with decreasing solid SOM content for each compound over the range of X studied. For the less-soluble pesticides, the K*(d)/K(d) ratios exhibited a large increase with X for bentonite, a marginal change (increase or decrease) for a soil of 2.4% SOM, and a moderate-to-large decrease for two soils of 14.8% and 86.4% SOM. These unique observations were rationalized in terms of the properties of the compound, the amount of surfactant sorbed on the solid, the enhanced solubilization of the compound by surfactant in water, and the relative effects of the surfactant when adsorbed on minerals and when partitioned into SOM. (C) 2000 Academic Press.

The improvement of the analytical performance of direct current atmospheric pressure glow discharge generated in contact with the small-sized liquid cathode after the addition of non-ionic surfactants to electrolyte solutions.

PubMed

Gręda, Krzysztof; Jamróz, Piotr; Pohl, Paweł

2013-04-15

A low power direct current atmospheric glow discharge sustained in the open to air atmosphere in contact with a small-sized flowing liquid cathode was used as an excitation source in optical emission spectrometry. The composition of electrolyte solutions served as the liquid cathode was modified by the addition of non-ionic surfactants, namely Triton x-45, Triton x-100, Triton x-405 and Triton x-705. The effect of the concentration of each surfactant was thoroughly studied on the emission characteristic of molecular bands identified in spectra, atomic emission lines of 16 metals studied and the background level. It was found that the presence of both heavy surfactants results in a significant increase in the net intensity of analytical lines of metals and a notable reduction of the intensity of bands of diatomic molecules and the background. In conditions considered to be a compromise for all metals, selected figures of merit for this excitation source combined with the optical emission spectrometry detection were determined. Limits of detection for all metals were within the range of 0.0003-0.05 mg L(-1), the precision was better than 6%, while calibration curves were linear over 2 orders of the magnitude of the concentration or more, e.g., for K, Li, Mg, Na and Rb. The discharge system with the liquid cathode modified by the addition of the surfactant found its application in the determination of Ca, Cu, Fe, K, Mg, Mn, Na and Zn in selected environmental samples, i.e., waters, soils and spruce needles, with the quite good precision and the accuracy comparable to that for measurements with flame atomic absorption spectrometry (FAAS) and flame atomic emission spectrometry (FAES). Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis and characterization of anionic/nonionic surfactant-interceded iron-doped TiO{sub 2} to enhance sorbent/photo-catalytic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Ajit; Lee, Byeong-Kyu, E-mail: bklee@ulsan.ac.kr

2015-09-15

We investigated the synthesis, characterization, and application of surfactant-interceded Fe nanoparticle-doped TiO{sub 2} (TiO{sub 2}/Fe-S1 and TiO{sub 2}/Fe-S2) that were used as adsorbents and photo-catalysts for the removal of As(V) ions from aqueous media. Two types of surfactant (anionic (sodium dodecyl sulfate), S1 and non-ionic (Triton X-100), S2) were used to obtain the separation and mono-dispersion of Fe(III) ions in the reaction solution. The nanocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), UV–vis, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) and elemental mapping analysis before and after As(V) removal. The Langmuir capacities (q{submore » e}, mg/g) of the sodium dodecyl sulfate (SDS) and Triton X-100 interceded nanocomposites (TiO{sub 2}/Fe-S1 and TiO{sub 2}/Fe-S2, respectively) for arsenic removal were determined to be 65.79 and 50.76 mg/g, respectively, in aqueous media with As(V) concentration ranges of 0–10 mg/L at pH 6.5. - Highlights: • Fe(III) doped TiO{sub 2} nanocomposite was prepared with surfactant. • Anionic surfactant SDS enhanced the transfer of Fe(III) ions to TiO{sub 2}. • Surfactant-interceded nanocomposite enhanced As(V) removal. • Arsenic removal efficiency was as follows: dark phase>visible phase>UV region.« less

Investigation of an optimal cell lysis method for the study of the zinc metalloproteome of Histoplasma capsulatum.

PubMed

Donnell, Anna M; Lewis, Stephanie; Abraham, Sami; Subramanian, Kavitha; Figueroa, Julio Landero; Deepe, George S; Vonderheide, Anne P

2017-10-01

This work sought to assess optimal extraction conditions in the study of the metalloproteome of the dimorphic fungus Histoplasma capsulatum. One of the body's responses to H. capsulatum infection is sequestration of zinc within host macrophage (MØ), as reported by Vignesh et al. (Immunity 39:697-710, 2013) and Vignesh et al. (PLOS Pathog 9:E1003815, 2013). Thus, metalloproteins containing zinc were of greatest interest as it plays a critical role in survival of the fungus. One challenge in metalloproteomics is the preservation of the native structure of proteins to retain non-covalently bound metals. Many of the conventional cell lysis, separation, and identification techniques in proteomics are carried out under conditions that could lead to protein denaturation. Various cell lysis techniques were investigated in an effort to both maintain the metalloproteins during lysis and subsequent analysis while, at the same time, serving to be strong enough to break the cell wall, allowing access to cytosolic metalloproteins. The addition of 1% Triton x-100, a non-ionic detergent, to the lysis buffer was also studied. Seven lysis methods were considered and these included: Glass Homogenizer (H), Bead Beater (BB), Sonication Probe (SP), Vortex with 1% Triton x-100 (V, T), Vortex with no Triton x-100 (V, NT), Sonication Bath, Vortex, and 1% Triton x-100 (SB, V, T) and Sonication Bath, Vortex, and no Triton x-100 (SB, V, NT). A Qubit® Assay was used to compare total protein concentration and inductively coupled plasma-mass spectrometry (ICP-MS) was utilized for total metal analysis of cell lysates. Size exclusion chromatography coupled to ICP-MS (SEC-HPLC-ICP-MS) was used for separation of the metalloproteins in the cell lysate and the concentration of Zn over a wide molecular weight range was examined. Additional factors such as potential contamination sources were also considered. A cell lysis method involving vortexing H. capsulatum yeast cells with 500 μm glass beads in a 1% Triton x-100 lysis buffer (V, T) was found to be most advantageous to extract intact zinc metalloproteins as demonstrated by the highest Zn to protein ratio, 1.030 ng Zn/μg protein, and Zn distribution among high, mid, and low molecular weights suggesting the least amount of protein denaturation. Graphical abstract In this work, several cell lysis techniques and two lysis buffers were investigated to evaluate the preservation of the zinc metalloproteome of H. capsulatum while maintaining compatibility with the analytical techniques employed.

The effects of non-ionic polymeric surfactants on the cleaning of biofouled hydrogel materials.

PubMed

Guan, Allan; Li, Zhenyu; Phillips, K Scott

2015-01-01

Block co-polymer surfactants have been used for cleaning hydrogel medical devices that contact the body (e.g., contact lenses) because of their biocompatibility. This work examined the relationship between concentration and detergency of two non-ionic polymeric surfactants (Pluronic F127 and Triton X-100) for cleaning protein soil, with anionic surfactants (sodium dodecyl sulfate and sodium laureth sulfate) as positive controls. Surface plasmon resonance was used to quantify removal of simulated tear soil from self-assembled monolayer surfaces, and a microplate format was used to study the removal of fluorescently labeled soil proteins from contact lenses. While detergency increased as a function of concentration for anionic surfactants, it decreased with concentration for the two polymeric surfactants. The fact that the protein detergency of some non-ionic polymeric surfactants did not increase with concentration above the critical micelle concentration could have implications for optimizing the tradeoff between detergency and biocompatibility.

Tween-20 transiently changes the surface morphology of PK-15 cells and improves PCV2 infection.

PubMed

Hua, Tao; Zhang, Xuehua; Tang, Bo; Chang, Chen; Liu, Guoyang; Feng, Lei; Yu, Yang; Zhang, Daohua; Hou, Jibo

2018-04-24

Low concentrations of nonionic surfactants can change the physical properties of cell membranes, and thus and in turn increase drug permeability. Porcine circovirus 2 (PCV2) is an extremely slow-growing virus, and PCV2 infection of PK-15 cells yields very low viral titers. The present study investigates the effect of various nonionic surfactants, namely, Tween-20, Tween-28, Tween-40, Tween-80, Brij-30, Brij-35, NP-40, and Triton X-100 on PCV2 infection and yield in PK-15 cells. Significantly increased PCV2 infection was observed in cells treated with Tween-20 compared to those treated with Tween-28, Tween-40, Brij-30, Brij-35, NP-40, and Triton X-100 (p < 0.01). Furthermore, 24 h incubation with 0.03% Tween-20 has shown to induce significant cellular morphologic changes (cell membrane underwent slight intumescence and bulged into a balloon, and the number of microvilli decreased), as well as to increase caspase-3 activity and to decrease cell viability in PCV2-infected PK-15 cells cmpared to control group; all these changes were restored to normal after Tween-20 has been washed out from the plate. Our data demonstrate that Tween-20 transiently changes the surface morphology of PK-15 cells and improves PCV2 infection. The findings of the present study may be utilized in the development of a PCV2 vaccine.

Extracellular accumulation of recombinant protein by Escherichia coli in a defined medium.

PubMed

Fu, Xiang-Yang

2010-09-01

Extracellular accumulation of recombinant proteins in the culture medium of Escherichia coli is desirable but difficult to obtain. The inner or cytoplasmic membrane and the outer membrane of E. coli are two barriers for releasing recombinant proteins expressed in the cytoplasm into the culture medium. Even if recombinant proteins have been exported into the periplasm, a space between the outer membrane and the inner membrane, the outer membrane remains the last barrier for their extracellular release. However, when E. coli was cultured in a particular defined medium, recombinant proteins exported into the periplasm could diffuse into the culture medium automatically. If a nonionic detergent, Triton X-100, was added in the medium, recombinant proteins expressed in the cytoplasm could also be released into the culture medium. It was then that extracellular accumulation of recombinant proteins could be obtained by exporting them into the periplasm or releasing them from the cytoplasm with Triton X-100 addition. The tactics described herein provided simple and valuable methods for achieving extracellular production of recombinant proteins in E. coli.

Probing pH difference between micellar solution and nanoscale water within common black film by fluorescent dye

NASA Astrophysics Data System (ADS)

Fu, Jingni; Zhang, Luning

2018-03-01

The protonation/deprotonation equilibrium of a fluorescent pH probe (carboxy-seminaphthorhodafluor-1, SNARF-1) within the nanoscale water layer confined in common black films (CBFs) has been studied. We find that SNARF-1 molecules feel a more acidic environment in CBFs than when they are in the bulk micellar solution, using the base/acid peak area ratio of the dye to indicate its microenvironment pH. Three surfactants are used to study the dependence of the pH drop versus charge: cationic (cetyltrimethylammonium bromide, CTAB), anionic (sodium dodecylsulphate, SDS) and nonionic (Triton X-100) species. The decrease of CBFs pH versus the pH of the micellar solution is the following: ΔpH ≈ 1.5 for CTAB (pH: 7.0-9.0), ΔpH ≈ 0.8 for SDS, and ΔpH ≈ 0.4 for Triton X-100. With the addition of electrolyte in CBFs, we observe large decrease the amplitude of the pH anomaly, thus suggesting an electrostatic origin of the pH change at nanoscale environment.

[Rapid and efficient extraction of soluble proteins from gram-negative microorganisms without disruption of cell walls].

PubMed

Danilevich, V N; Petrovskaia, L E; Grishin, E V

2006-01-01

The ability of buffer solutions containing low concentrations of nonionic detergents (Triton X-100, Tween 20, Brij 58, and Lubrol PX) and the anionic detergent sodium deoxycholate, as well as mixtures of these detergents with chaeotropes (urea and guanidine hydrochloride), to extract intracellular proteins of Gram-negative microorganisms (Escherichia coli and Pseudomonas aeruginosa) was studied. It was established that the solutions containing Triton X-100 and sodium deoxycholate and the mixtures of these detergents with urea are the most effective. It was shown that the extraction of proteins from bacterial cells under the studied conditions is not accompanied by a release of DNA into solution but is associated with extraction of low-molecular RNAs. The level of protein extraction reaches 80%. No disruption of the bacterial cell wall occurs during the extraction, and proteins probably permeate through meshes of the murein network. The efficiencies of our buffer mixtures are close to or higher than that of the commercial reagent CelLytic B (Sigma, United States). The practical uses of the chaeotropic mixtures developed are discussed.

Formulation of a Broad-Spectrum, All-Weather, Solid-Based, Peracetate - Solvent Dry Decontaminant Concentrate

DTIC Science & Technology

2010-04-01

PAB 17 2.5.2 PAB/SPC Mixtures 17 2.5.3 PAB/SPC Mixtures with Ethylene Carbonate 19 2.5.4 Peroxydone/PAB Mixtures 19 2.5.4.1 Chem Agent Testing 19...Effect of Surfactant and Ethylene Carbonate (EC) Penetrant on Decontamination of HD on CARC Painted Panels 20 5. Effect of Surfactant, Alone, on...previous peroxide-based decontaminants7൓ (i.e., Triton® X-100 (non-ionic surfactant) and propylene carbonate [PC]) could not be used. However, there

Adsorption of hydrophobic organic compounds onto a hydrophobic carbonaceous geosorbent in the presence of surfactants.

PubMed

Wang, Peng; Keller, Arturo A

2008-06-01

The adsorption of hydrophobic organic compounds (HOCs; atrazine and diuron) onto lampblack was studied in the presence of nonionic, cationic, and anionic surfactants (Triton(R) X-100), benzalkonium chloride [BC], and linear alkylbenzene sulfonate [LAS]) to determine the effect of the surfactant on HOC adsorption onto a hydrophobic carbonaceous geosorbent. Linear alkylbenzene sulfonate showed an adsorption capacity higher than that of BC but similar to that of Triton X-100, implying the charge property of a surfactant is not a useful indicator for predicting the surfactant's adsorption onto a hydrophobic medium. The results also indicated that the octanol-water partition coefficient (K(OW)) of a surfactant is not a good predictor of that surfactant's sorption onto a hydrophobic medium. Under subsaturation adsorption conditions (i.e., before sorption saturation is reached), surfactant adsorption reduced HOC adsorption to a significant extent, with the reduction in HOC adsorption increasing monotonically with the amount of surfactant adsorbed. Among the three surfactants, Triton X-100 was the most effective in reducing HOC adsorption, whereas BC and LAS showed similar effectiveness in this regard. Under the same amount of the surfactant sorbed, the reduction in atrazine adsorption was consistently greater than that for diuron because of atrazine's lower hydrophobicity. No significant difference was observed in the amount of the HOC adsorbed under different adsorption sequences. Our results showed that the presence of surfactant can significantly decrease HOC adsorption onto hydrophobic environmental media and, thus, is important in predicting HOC fate and transport in the environment.

Controlling the Interfacial Environment in the Electrosynthesis of MnOx Nanostructures for High-Performance Oxygen Reduction/Evolution Electrocatalysis.

PubMed

Hosseini-Benhangi, Pooya; Kung, Chun Haow; Alfantazi, Akram; Gyenge, Elöd L

2017-08-16

High-performance, nonprecious metal bifunctional electrocatalysts for the oxygen reduction and evolution reactions (ORR and OER, respectively) are of great importance for rechargeable metal-air batteries and regenerative fuel cells. A comprehensive study based on statistical design of experiments is presented to investigate and optimize the surfactant-assisted structure and the resultant bifunctional ORR/OER activity of anodically deposited manganese oxide (MnO x ) catalysts. Three classes of surfactants are studied: anionic (sodium dodecyl sulfate, SDS), non-ionic (t-octylphenoxypolyethoxyethanol, Triton X-100), and cationic (cetyltrimethylammonium bromide, CTAB). The adsorption of surfactants has two main effects: increased deposition current density due to higher Mn 2+ and Mn 3+ concentrations at the outer Helmholtz plane (Frumkin effect on the electrodeposition kinetics) and templating of the MnO x nanostructure. CTAB produces MnO x with nanoneedle (1D) morphology, whereas nanospherical- and nanopetal-like morphologies are obtained with SDS and Triton, respectively. The bifunctional performance is assessed based on three criteria: OER/ORR onset potential window (defined at 2 and -2 mA cm -2 ) and separately the ORR and OER mass activities. The best compromise among these three criteria is obtained either with Triton X-100 deposited catalyst composed of MnOOH and Mn 3 O 4 or SDS deposited catalyst containing a combination of α- and β-MnO 2 , MnOOH, and Mn 3 O 4 .The interaction effects among the deposition variables (surfactant type and concentration, anode potential, Mn 2+ concentration, and temperature) reveal the optimal strategy for high-activity bifunctional MnO x catalyst synthesis. Mass activities for OER and ORR up to 49 A g -1 (at 1556 mV RHE ) and -1.36 A g -1 (at 656 mV RHE ) are obtained, respectively.

Triton Hodge Test: Improved Protocol for Modified Hodge Test for Enhanced Detection of NDM and Other Carbapenemase Producers

PubMed Central

Pasteran, Fernando; Gonzalez, Lisandro J.; Albornoz, Ezequiel; Bahr, Guillermo; Vila, Alejandro J.

2015-01-01

Accurate detection of carbapenemase-producing Gram-negative bacilli is of utmost importance for the control of nosocomial spread and the initiation of appropriate antimicrobial therapy. The modified Hodge test (MHT), a carbapenem inactivation assay, has shown poor sensitivity in detecting the worldwide spread of New Delhi metallo-β-lactamase (NDM). Recent studies demonstrated that NDM is a lipoprotein anchored to the outer membrane in Gram-negative bacteria, unlike all other known carbapenemases. Here we report that membrane anchoring of β-lactamases precludes detection of carbapenemase activity by the MHT. We also show that this limitation can be overcome by the addition of Triton X-100 during the test, which allows detection of NDM. We propose an improved version of the assay, called the Triton Hodge test (THT), which allows detection of membrane-bound carbapenemases with the addition of this nonionic surfactant. This test was challenged with a panel of 185 clinical isolates (145 carrying known carbapenemase-encoding genes and 40 carbapenemase nonproducers). The THT displayed test sensitivity of >90% against NDM-producing clinical isolates, while improving performance against other carbapenemases. Ertapenem provided the highest sensitivity (97 to 100%, depending on the type of carbapenemase), followed by meropenem (92.5 to 100%). Test specificity was not affected by the addition of Triton (87.5% and 92.5% with ertapenem and meropenem, respectively). This simple inexpensive test confers a large improvement to the sensitivity of the MHT for the detection of NDM and other carbapenemases. PMID:26719442

Removal of 226Ra and 228Ra from TENORM sludge waste using surfactants solutions.

PubMed

Attallah, M F; Hamed, Mostafa M; El Afifi, E M; Aly, H F

2015-01-01

The feasibility of using surfactants as extracting agent for the removal of radium species from TENORM sludge produced from petroleum industry is evaluated. In this investigation cationic and nonionic surfactants were used as extracting agents for the removal of radium radionuclides from the sludge waste. Two surfactants namely cetyltrimethylammonium bromide (CTAB) and Triton X-100 (TX100) were investigated as the extracting agents. Different parameters affecting the removal of both (226)Ra and (228)Ra by the two surfactants as well as their admixture were studied by the batch technique. These parameters include effect of shaking time, surfactants concentration and temperature as well as the effect of surfactants admixture. It was found that, higher solution temperature improves the removal efficiency of radium species. Combined extraction of nonionic and cationic surfactants produces synergistic effect in removal both (226)Ra and (228)Ra, where the removals reached 84% and 80% for (226)Ra and (228)Ra, respectively, were obtained using surfactants admixture. Copyright © 2014 Elsevier Ltd. All rights reserved.

Topographical analysis of the plasma membrane-associated sucrose binding protein from soybean.

PubMed

Overvoorde, P J; Grimes, H D

1994-05-27

Plasma membranes of soybean cells actively engaged in sucrose transport have a sucrose binding protein (SBP) that does not appear to be an integral membrane protein. Experiments were undertaken to analyze the topographical association of this protein with the membrane. Treatment of purified plasma membrane vesicles with either 1 M KCl or KI released less than 35% of the sucrose binding protein from the membrane whereas treatment with either 4 M urea or 0.1 M Na2CO3, pH 11.5, disassociated between 50 and 70%, respectively, of this protein from the membrane. SDS, at either 0.5x, 1x, or 10x of its critical micelle concentration, effectively solubilized the sucrose binding protein. The nonionic detergents Triton X-100 and CHAPS, at either 0.5x, 1x, or 10x of their critical micelle concentration, solubilized between 65 and 75% of this protein. When either native plasma membrane-associated or in vitro-transcribed and -translated SBP were subjected to Triton X-114 phase separation, 80% partitioned into the detergent-poor aqueous phase. These results indicate that the SBP is a peripheral membrane protein but also suggest that there is a population of this protein that is tethered to the membrane.

Synergistic cloud point extraction behavior of aluminum(III) with 2-methyl-8-quinolinol and 3,5-dichlorophenol.

PubMed

Ohashi, Akira; Tsuguchi, Akira; Imura, Hisanori; Ohashi, Kousaburo

2004-07-01

The cloud point extraction behavior of aluminum(III) with 8-quinolinol (HQ) or 2-methyl-8-quinolinol (HMQ) and Triton X-100 was investigated in the absence and presence of 3,5-dichlorophenol (Hdcp). Aluminum(III) was almost extracted with HQ and 4(v/v)% Triton X-100 above pH 5.0, but was not extracted with HMQ-Triton X-100. However, in the presence of Hdcp, it was almost quantitatively extracted with HMQ-Triton X-100. The synergistic effect of Hdcp on the extraction of aluminum(III) with HMQ and Triton X-100 may be caused by the formation of a mixed-ligand complex, Al(dcp)(MQ)2.

Triton Hodge Test: Improved Protocol for Modified Hodge Test for Enhanced Detection of NDM and Other Carbapenemase Producers.

PubMed

Pasteran, Fernando; Gonzalez, Lisandro J; Albornoz, Ezequiel; Bahr, Guillermo; Vila, Alejandro J; Corso, Alejandra

2016-03-01

Accurate detection of carbapenemase-producing Gram-negative bacilli is of utmost importance for the control of nosocomial spread and the initiation of appropriate antimicrobial therapy. The modified Hodge test (MHT), a carbapenem inactivation assay, has shown poor sensitivity in detecting the worldwide spread of New Delhi metallo-β-lactamase (NDM). Recent studies demonstrated that NDM is a lipoprotein anchored to the outer membrane in Gram-negative bacteria, unlike all other known carbapenemases. Here we report that membrane anchoring of β-lactamases precludes detection of carbapenemase activity by the MHT. We also show that this limitation can be overcome by the addition of Triton X-100 during the test, which allows detection of NDM. We propose an improved version of the assay, called the Triton Hodge test (THT), which allows detection of membrane-bound carbapenemases with the addition of this nonionic surfactant. This test was challenged with a panel of 185 clinical isolates (145 carrying known carbapenemase-encoding genes and 40 carbapenemase nonproducers). The THT displayed test sensitivity of >90% against NDM-producing clinical isolates, while improving performance against other carbapenemases. Ertapenem provided the highest sensitivity (97 to 100%, depending on the type of carbapenemase), followed by meropenem (92.5 to 100%). Test specificity was not affected by the addition of Triton (87.5% and 92.5% with ertapenem and meropenem, respectively). This simple inexpensive test confers a large improvement to the sensitivity of the MHT for the detection of NDM and other carbapenemases. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

In situ SAXS study on cationic and non-ionic surfactant liquid crystals using synchrotron radiation.

PubMed

Fritscher, C; Hüsing, N; Bernstorff, S; Brandhuber, D; Koch, T; Seidler, S; Lichtenegger, H C

2005-11-01

In situ synchrotron small-angle X-ray scattering was used to investigate various surfactant/water systems with hexagonal and lamellar structures regarding their structural behaviour upon heating and cooling. Measurements of the non-ionic surfactant Triton X-45 (polyethylene glycol 4-tert-octylphenyl ether) at different surfactant concentrations show an alignment of the lamellar liquid-crystalline structure close to the wall of the glass capillaries and also a decrease in d-spacing following subsequent heating/cooling cycles. Additionally, samples were subjected to a weak magnetic field (0.3-0.7 T) during heating and cooling, but no influence of the magnetic field was observed.

Enhanced photocatalytic degradation of norfloxacin in aqueous Bi2WO6 dispersions containing nonionic surfactant under visible light irradiation.

PubMed

Tang, Lin; Wang, Jiajia; Zeng, Guangming; Liu, Yani; Deng, Yaocheng; Zhou, Yaoyu; Tang, Jing; Wang, Jingjing; Guo, Zhi

2016-04-05

Photocatalytic degradation is an alternative method to remove pharmaceutical compounds in water, however it is hard to achieve efficient rate because of the poor solubility of pharmaceutical compounds in water. This study investigated the photodegradation of norfloxacin in a nonionic surfactant Triton-X100 (TX100)/Bi2WO6 dispersion under visible light irradiation (400-750nm). It was found that the degradation of poorly soluble NOF can be strongly enhanced with the addition of TX100. TX100 was adsorbed strongly on Bi2WO6 surface and accelerated NOF photodegradation at the critical micelle concentration (CMC=0.25mM). Higher TX100 concentration (>0.25mM) lowered the degradation rate. In the presence of TX100, the degradation rate reached the maximum value when the pH value was 8.06. FTIR analyses demonstrated that the adsorbed NOF on the catalyst was completely degraded after 2h irradiation. According to the intermediates identified by HPLC/MS/MS, three possible degradation pathways were proposed to include addition of hydroxyl radical to quinolone ring, elimination of piperazynilic ring in fluoroquinolone molecules, and replacement of F atoms on the aromatic ring by hydroxyl radicals. Copyright © 2015 Elsevier B.V. All rights reserved.

Minimized virus binding for tests of barrier materials.

PubMed Central

Lytle, C D; Routson, L B

1995-01-01

Viruses are used to test the barrier properties of materials. Binding of virus particles during passage through holes in the material may yield misleading test results. The choices of challenge virus and suspending medium may be important for minimizing confounding effects that might arise from such binding. In this study, different surrogate viruses, as well as different support media, were evaluated to determine optimal test parameters. Two membranes with high-binding properties (nitrocellulose and cationic polysulfone) were used as filters to compare binding activities of different surrogate challenge viruses (MS2, phi X174, T7, PRD1, and phi 6) in different media. The media consisted of buffered saline with surfactants, serum, or culture broth as additives. In addition, elution rates of viruses that bound to the membranes were determined. The results suggest that viruses can bind by hydrophobic and electrostatic interactions, with phi X174 displaying the lowest level of binding by either process. The nonionic detergents Triton X-100 and Tween 80 (0.1%) equally minimized hydrophobic interactions. Neither anionic nor cationic surfactants were as effective at nontoxic levels. Serum was effective at reducing both hydrophobic and electrostatic binding, with 2% being sufficient for eliminating binding under our test conditions. Thus, phi X174 remains the best choice as a surrogate virus to test barrier materials, and Triton X-100 (0.1%) remains a good choice for reducing hydrophobic binding. In addition, binding of viruses by barrier materials is unlikely to prevent passage of blood-borne pathogens. PMID:7574603

Utilization of Triton X-100 and polyethylene glycols during surfactant-mediated biodegradation of diesel fuel.

PubMed

Wyrwas, Bogdan; Chrzanowski, Łukasz; Ławniczak, Łukasz; Szulc, Alicja; Cyplik, Paweł; Białas, Wojciech; Szymański, Andrzej; Hołderna-Odachowska, Aleksandra

2011-12-15

The hypothesis regarding preferential biodegradation of surfactants applied for enhancement of microbial hydrocarbons degradation was studied. At first the microbial degradation of sole Triton X-100 by soil isolated hydrocarbon degrading bacterial consortium was confirmed under both full and limited aeration with nitrate as an electron acceptor. Triton X-100 (600 mg/l) was utilized twice as fast for aerobic conditions (t(1/2)=10.3h), compared to anaerobic conditions (t(1/2)=21.8h). HPLC/ESI-MS analysis revealed the preferential biodegradation trends in both components classes of commercial Triton X-100 (alkylphenol ethoxylates) as well as polyethylene glycols. The obtained results suggest that the observed changes in the degree of ethoxylation for polyethylene glycol homologues occurred as a consequence of the 'central fission' mechanism during Triton X-100 biodegradation. Subsequent experiments with Triton X-100 at approx. CMC concentration (150 mg/l) and diesel oil supported our initial hypothesis that the surfactant would become the preferred carbon source even for hydrocarbon degrading bacteria. Regardless of aeration regimes Triton X-100 was utilized within 48-72 h. Efficiency of diesel oil degradation was decreased in the presence of surfactant for aerobic conditions by approx. 25% reaching 60 instead of 80% noted for experiments without surfactant. No surfactant influence was observed for anaerobic conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

Novel Procedure for Extraction of a Latent Grape Polyphenoloxidase Using Temperature-Induced Phase Separation in Triton X-114 1

PubMed Central

Sánchez-Ferrer, Alvaro; Bru, Roque; Garcia-Carmona, Francisco

1989-01-01

Polyphenoloxidase from grape berries is extracted only by nonionic detergents with a hydrophilic-lipophilic balance between 12.4 and 13.5. The enzyme was partially purified in latent form, free of phenolics and chlorophylls, by using temperature phase partitioning in a solution of Triton X-114. This method permits the purification of the enzyme with the same fold purification as the commonly used method, but with a yield three times higher and a 90% reduction in time needed. The latent enzyme can be activated by different treatments, including trypsin and cationic and anionic detergents. Cetyltrimethylamonium bromide was found to be the most effective detergent activator, followed by sodium dodecyl sulfate. Polyphenoloxidase in grape berries, in spite of being an integral membrane protein, had an anomalous interaction with Triton X-114, remaining in the detergent-poor phase after phase separation. This could be explained by its having a short hydrophobic tail that anchors it to the membrane. Images Figure 1 Figure 3 PMID:16667205

Bacterial properties changing under Triton X-100 presence in the diesel oil biodegradation systems: from surface and cellular changes to mono- and dioxygenases activities.

PubMed

Sałek, Karina; Kaczorek, Ewa; Guzik, Urszula; Zgoła-Grześkowiak, Agnieszka

2015-03-01

Triton X-100, as one of the most popular surfactants used in bioremediation techniques, has been reported as an effective agent enhancing the biodegradation of hydrocarbons. However efficient, the surfactant's role in different processes that together enable the satisfying biodegradation should be thoroughly analysed and verified. In this research, we present the interactions of Triton X-100 with the bacterial surfaces (hydrophobicity and zeta potential), its influence on the enzymatic properties (considering mono- and dioxygenases) and profiles of fatty acids, which then all together were compared with the biodegradation rates. The addition of various concentrations of Triton X-100 to diesel oil system revealed different cell surface hydrophobicity (CSH) of the tested strains. The results demonstrated that for Pseudomonas stutzeri strain 9, higher diesel oil biodegradation was correlated with hydrophilic properties of the tested strain and lower Triton X-100 biodegradation. Furthermore, an increase of the branched fatty acids was observed for this strain.

[Effects of Triton X-100 on the oxygen uptake rate of photosystem I particles treated at 70 degrees C].

PubMed

Chen, Wei; Yang, Zhen-Le; Li, Liang-Bi; Kuang, Ting-Yun

2005-06-01

The characteristics including oxygen uptake rates, fluorescence spectra and absorption spectra of photosystem I particles with or without Triton-X 100 treatment before or after the incubation at 70 degrees C for 10 min were compared. The oxygen uptake rates of photosystem I particles decreased after being incubated at 70 degrees C for 10 min, which could be recovered by the addition of Triton-X 100. Singlet oxygen was formed when the light-harvesting complex I was separated from the core complex of photosystem I, which resulted in high oxygen uptake rate. There was much difference in the fluorescence spectra of photosystem I particles between photosystem I particles treated with Triton-X 100 after the incubation at 70 degrees C for 10 min or not, which implies the ability of Triton-X 100 to promote the recovery of photosystem I particles after the incubation at 70 degrees C for 10 min.

Extraction and separation of tungsten (VI) from aqueous media with Triton X-100-ammonium sulfate-water aqueous two-phase system without any extractant.

PubMed

Yongqiang Zhang; Tichang Sun; Tieqiang Lu; Chunhuan Yan

2016-11-25

An aqueous two-phase system composed of Triton X-100-(NH 4 ) 2 SO 4 -H 2 O was proposed for extraction and separation of tungsten(VI) from aqueous solution without using any extractant. The effects of aqueous pH, concentration of ammonium sulfate, Triton X-100 and tungsten, extracting temperature on the extraction of tungsten were investigated. The extraction of tungsten has remarkable relationship with aqueous pH and are to above 90% at pH=1.0-3.0 under studied pH range (pH=1.0-7.0) and increases gradually with increasing Triton X-100 concentration, but decreases slightly with increasing ammonium sulfate concentration. The extraction percentage of tungsten is hardly relevant to temperature but its distribution coefficient linearly increases with increasing temperature within 303.15-343.15K. The distribution coefficient of tungsten increases with the increase of initial tungsten concentration (0.1-3%) and temperature (303.15 K-333.15K). The solubilization capacity of tungsten in Triton X-100 micellar phase is independent of temperature. FT-IR analysis reveals that there is no evident interaction between polytungstate anion and ether oxygen unit in Triton X-100, and DLS analysis indicates that zeta potential of Triton X-100 micellar phase have a little change from positive to negative after extracting tungsten. Based on the above-mentioned results, it can be deduced that polytungstate anions are solubilized in hydrophilic outer shell of Triton X-100 micelles by electrostatic attraction depending on its relatively high hydrophobic nature. The stripping of tungsten is mainly influenced by temperature and can be easily achieved to 95% in single stage stripping. The tungsten (VI) is separated out from solution containing Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Al(III), Cr(III) and Mn(II) under the suitable conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Antioxidant capacity of pure compounds and complex mixtures evaluated by the ORAC-pyrogallol red assay in the presence of Triton X-100 micelles.

PubMed

Romero, Max; Rojano, Benjamin; Mella-Raipán, Jaime; Pessoa-Mahana, Carlos David; Lissi, Eduardo; López-Alarcón, Camilo

2010-09-01

The protective effect of different antioxidants and complex mixtures on the consumption of pyrogallol red (PGR) induced by peroxyl radicals was studied in the absence and presence of Triton X-100 micelles. The presence of micelles decreased significantly the protection of PGR afforded by lipophilic antioxidants (β-carotene, octyl gallate), while no effect of micelles was observed for hydrophilic antioxidants such as Trolox, caffeic acid, gallic acid, and ascorbic acid. In the presence of complex mixtures a clear effect of Triton X-100 micelles was also observed in the protection afforded by wines, tea infusions, and seed extracts of Eugenia jambolana and Myrciaria cauliflora. On the other hand, no effect of micelles was observed for orange juice and pulp fruit extracts. The ORAC (Oxygen Radical Absorbance Capacity) index was evaluated in the absence (ORAC-PGR) and presence of Triton X-100 micelles (ORAC-PGR(MIC)). Triton X-100 micelles affect ORAC-PGR values of antioxidants in a lipophilicity-dependent way. From the obtained results, we conclude that ORAC-PGR and ORAC-PGR(MIC) assays could be considered as an alternative to estimate the antioxidant ability (ORAC-PGR) and to infer the association to Triton X-100 micelles (ORAC-PGR/ORAC-PGR(MIC)) of pure antioxidants and their complex mixtures.

Spectrophotometric determination of paracetamol in urine with tetrahydroxycalix[4]arene as a coupling reagent and preconcentration with triton X-114 using cloud point extraction.

PubMed

Filik, Hayati; Sener, Izzet; Cekiç, Sema Demirci; Kiliç, Emine; Apak, Reşat

2006-06-01

In the present paper, conventional spectrophotometry in conjunction with cloud point extraction-preconcentration were investigated as alternative methods for paracetamol (PCT) assay in urine samples. Cloud point extraction (CPE) was employed for the preconcentration of p-aminophenol (PAP) prior to spectrophotometric determination using the non-ionic surfactant Triton X-114 (TX-114) as an extractant. The developed methods were based on acidic hydrolysis of PCT to PAP, which reacted at room temperature with 25,26,27,28-tetrahydroxycalix[4]arene (CAL4) in the presence of an oxidant (KIO(4)) to form an blue colored product. The PAP-CAL4 blue dye formed was subsequently entrapped in the surfactant micelles of Triton X-114. Cloud point phase separation with the aid of Triton X-114 induced by addition of Na(2)SO(4) solution was performed at room temperature as an advantage over other CPE assays requiring elevated temperatures. The 580 nm-absorbance maximum of the formed product was shifted bathochromically to 590 nm with CPE. The working range of 1.5-12 microg ml(-1) achieved by conventional spectrophotometry was reduced down to 0.14-1.5 microg ml(-1) with cloud point extraction, which was lower than those of most literature flow-through assays that also suffer from nonspecific absorption in the UV region. By preconcentrating 10 ml sample solution, a detection limit as low as 40.0 ng ml(-1) was obtained after a single-step extraction, achieving a preconcentration factor of 10. The stoichiometric composition of the dye was found to be 1 : 4 (PAP : CAL4). The impact of a number of parameters such as concentrations of CAL4, KIO(4), Triton X-100 (TX-100), and TX-114, extraction temperature, time periods for incubation and centrifugation, and sample volume were investigated in detail. The determination of PAP in the presence of paracetamol in micellar systems under these conditions is limited. The established procedures were successfully adopted for the determination of PCT in urine samples. Since the drug is rapidly absorbed and excreted largely in urine and its high doses have been associated with lethal hepatic necrosis and renal failure, development of a rapid, sensitive and selective assay of PCT is of vital importance for fast urinary screening and antidote administration before applying more sophisticated, but costly and laborious hyphenated instrumental techniques of HPLC-SPE-NMR-MS.

Aqueous solution-chemical derived Nisbnd Al2O3 solar selective absorbing coatings. 2. Wetting agents and spreading of aqueous solutions on aluminum substrate

NASA Astrophysics Data System (ADS)

Li, Zhenxiang; Zhao, Jianxi

2013-03-01

Wettability of aluminum substrate by the aqueous solutions containing ethoxylated alcohol nonionic surfactants C12En- or Triton X-series was studied using dynamic contact angle measurements. The efficiency of wetting was found to strongly depend on the length of polyoxyethylene (POE) chain of C12En- or Triton X surfactants. For C12E4 that has a very short POE chain, it hardly made the aqueous solution spreading over aluminum. The others with a long POE chain were indeed very efficient in promoting the solution spreading. Moreover, all the spreading process could be completed within 10 s. The single-layer Nisbnd Al2O3 coatings were fabricated from the precursor solutions containing C12En- or Triton X surfactants and the reflectance spectra were measured by a UV/vis spectrophotometer equipped with an integrating sphere. The results indicated that the precursor solution with a long POE chain surfactant as wetting agent favored to fabricate a uniform film on the aluminum substrate and therefore to get a high solar absorptance.

Recellularizing of human acellular dermal matrices imaged by high-definition optical coherence tomography.

PubMed

Boone, Marc A L M; Draye, Jean Pierre; Verween, Gunther; Aiti, Annalisa; Pirnay, Jean-Paul; Verbeken, Gilbert; De Vos, Daniel; Rose, Thomas; Jennes, Serge; Jemec, Gregor B E; Del Marmol, Veronique

2015-05-01

High-definition optical coherence tomography (HD-OCT) permits real-time 3D imaging of the impact of selected agents on human skin allografts. The real-time 3D HD-OCT assessment of (i) the impact on morphological and cellular characteristics of the processing of human acellular dermal matrices (HADMs) and (ii) repopulation of HADMs in vitro by human fibroblasts and remodelling of the extracellular matrix by these cells. Four different skin decellularization methods, Dispase II/Triton X-100, Dispase II/SDS (sodium dodecyl sulphate), NaCl/Triton X-100 and NaCl/SDS, were analysed by HD-OCT. HD-OCT features of epidermal removal, dermo-epidermal junction (DEJ) integrity, cellularity and dermal architecture were correlated with reflectance confocal microscopy (RCM), histopathology and immunohistochemistry. Human adult dermal fibroblasts were in vitro seeded on the NaCl/Triton X-100 processed HADMs, cultured up to 19 days and evaluated by HD-OCT in comparison with MTT proliferation test and histology. Epidermis was effectively removed by all treatments. DEJ was best preserved after NaCl/Triton X-100 treatment. Dispase II/SDS treatment seemed to remove all cellular debris in comparison with NaCl/Triton X-100 but disturbed the DEJ severely. The dermal micro-architectural structure and vascular spaces of (sub)papillary dermis were best preserved with the NaCl/Triton X-100. The impact on the 3D structure and vascular holes was detrimental with Dispase II/SDS. Elastic fibre fragmentation was only observed after Dispase II incubation. HD-OCT showed that NaCl/Triton X-100 processed matrices permitted in vitro repopulation by human dermal fibroblasts (confirmed by MTT test and histology) and underwent remodelling upon increasing incubation time. Care must be taken in choosing the appropriate processing steps to maintain selected properties of the extracellular matrix in HADMs. Processing HADMs with NaCl/Triton X-100 permits in vitro the proliferation and remodelling activity of human dermal fibroblasts. HD-OCT provides unique real-time and non-invasive 3D imaging of tissue-engineered skin constructs and complementary morphological and cytological information. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Atomic force microscopy observation of lipopolysaccharide-induced cardiomyocyte cytoskeleton reorganization.

PubMed

Wang, Liqun; Chen, Tangting; Zhou, Xiang; Huang, Qiaobing; Jin, Chunhua

2013-08-01

We applied atomic force microscopy (AFM) to observe lipopolysaccharide (LPS)-induced intracellular cytoskeleton reorganization in primary cardiomyocytes from neonatal mouse. The nonionic detergent Triton X-100 was used to remove the membrane, soluble proteins, and organelles from the cell. The remaining cytoskeleton can then be directly visualized by AFM. Using three-dimensional technique of AFM, we were able to quantify the changes of cytoskeleton by the "density" and total "volume" of the cytoskeleton fibers. Compared to the control group, the density of cytoskeleton was remarkably decreased and the volume of cytoskeleton was significantly increased after LPS treatment, which suggests that LPS may induce the cytoskeleton reorganization and change the cardiomyocyte morphology. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hydrophobic tail length plays a pivotal role in amyloid beta (25-35) fibril-surfactant interactions.

PubMed

Bag, Sudipta; Chaudhury, Susmitnarayan; Pramanik, Dibyendu; DasGupta, Sunando; Dasgupta, Swagata

2016-09-01

The amyloid β-peptide fragment comprising residues 25-35 (Aβ25-35 ) is known to be the most toxic fragment of the full length Aβ peptide which undergoes fibrillation very rapidly. In the present work, we have investigated the effects of the micellar environment (cationic, anionic, and nonionic) on preformed Aβ25-35 fibrils. The amyloid fibrils have been prepared and characterized by several biophysical and microscopic techniques. Effects of cationic dodecyl trimethyl ammonium bromide (DTAB), cetyl trimethylammonium bromide (CTAB), anionic sodium dodecyl sulfate (SDS), and nonionic polyoxyethyleneoctyl phenyl ether (Triton X-100 or TX) on fibrils have been studied by Thioflavin T fluorescence, UV-vis spectroscopy based turbidity assay and microscopic analyses. Interestingly, DTAB and SDS micelles were observed to disintegrate prepared fibrils to some extent irrespective of their charges. CTAB micelles were found to break down the fibrillar assembly to a greater extent. On the other hand, the nonionic surfactant TX was found to trigger the fibrillation process. The presence of a longer hydrophobic tail in case of CTAB is assumed to be a reason for its higher fibril disaggregating efficacy, the premise of their formation being largely attributed to hydrophobic interactions. Proteins 2016; 84:1213-1223. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Cloud point extraction of iron(III) and vanadium(V) using 8-quinolinol derivatives and Triton X-100 and determination of 10(-7)moldm(-3) level iron(III) in riverine water reference by a graphite furnace atomic absorption spectroscopy.

PubMed

Ohashi, Akira; Ito, Hiromi; Kanai, Chikako; Imura, Hisanori; Ohashi, Kousaburo

2005-01-30

The cloud point extraction behavior of iron(III) and vanadium(V) using 8-quinolinol derivatives (HA) such as 8-quinolinol (HQ), 2-methyl-8-quinolinol (HMQ), 5-butyloxymethyl-8-quinolinol (HO(4)Q), 5-hexyloxymethyl-8-quinolinol (HO(6)Q), and 2-methyl-5-octyloxymethyl-8-quinolinol (HMO(8)Q) and Triton X-100 solution was investigated. Iron(III) was extracted with HA and 4% (v/v) Triton X-100 in the pH range of 1.70-5.44. Above pH 4.0, more than 95% of iron(III) was extracted with HQ, HMQ, and HMO(8)Q. Vanadium(V) was also extracted with HA and 4% (v/v) Triton X-100 in the pH range of 2.07-5.00, and the extractability increased in the following order of HMQ < HQ < HO(4)Q < HO(6)Q. The cloud point extraction was applied to the determination of iron(III) in the riverine water reference by a graphite furnace atomic absorption spectroscopy. When 1.25 x 10(-3)M HMQ and 1% (v/v) Triton X-100 were used, the found values showed a good agreement with the certified ones within the 2% of the R.S.D. Moreover, the effect of an alkyl group on the solubility of 5-alkyloxymethyl-8-quinolinol and 2-methyl-5-alkyloxymethyl-8-quinolinol in 4% (v/v) Triton X-100 at 25 degrees C was also investigated.

Dependence of the product chain-length on detergents for long-chain E-polyprenyl diphosphate synthases

PubMed Central

Pan, Jian-Jung; Ramamoorthy, Gurusankar; Poulter, C. Dale

2013-01-01

Long-chain E-polyprenyl diphosphate synthases (E-PDS) catalyze repetitive addition of isopentenyl diphosphate (IPP) to the growing prenyl chain of an allylic diphosphate. The polyprenyl diphosphate products are required for the biosynthesis of ubiquinones and menaquinones required for electron transport during oxidative phosphorylation to generate ATP. In vitro, the long-chain PDSs require addition of phospholipids or detergents to the assay buffer to enhance product release and maintain efficient turnover. During preliminary assays of product chain-length with anionic, zwitterionic, and non-ionic detergents, we discovered considerable variability. Examination of a series of non-ionic PEG detergents with several long-chain E-PDSs from different organisms revealed that in vitro incubations with nonaethylene glycol monododecyl ether or Triton X-100 typically gave chain lengths that corresponded to those of the isoprenoid moieties in respiratory quinones synthesized in vivo. In contrast incubations in buffer with n-butanol, CHAPS, DMSO, n-octyl-β-glucopyranoside, or β-cyclodextrin or in buffer without detergent typically proceeded more slowly and gave a broad range of chain lengths. PMID:23802587

Determination of rhodium in metallic alloy and water samples using cloud point extraction coupled with spectrophotometric technique

NASA Astrophysics Data System (ADS)

Kassem, Mohammed A.; Amin, Alaa S.

2015-02-01

A new method to estimate rhodium in different samples at trace levels had been developed. Rhodium was complexed with 5-(4‧-nitro-2‧,6‧-dichlorophenylazo)-6-hydroxypyrimidine-2,4-dione (NDPHPD) as a complexing agent in an aqueous medium and concentrated by using Triton X-114 as a surfactant. The investigated rhodium complex was preconcentrated with cloud point extraction process using the nonionic surfactant Triton X-114 to extract rhodium complex from aqueous solutions at pH 4.75. After the phase separation at 50 °C, the surfactant-rich phase was heated again at 100 °C to remove water after decantation and the remaining phase was dissolved using 0.5 mL of acetonitrile. Under optimum conditions, the calibration curve was linear for the concentration range of 0.5-75 ng mL-1 and the detection limit was 0.15 ng mL-1 of the original solution. The enhancement factor of 500 was achieved for 250 mL samples containing the analyte and relative standard deviations were ⩽1.50%. The method was found to be highly selective, fairly sensitive, simple, rapid and economical and safely applied for rhodium determination in different complex materials such as synthetic mixture of alloys and environmental water samples.

Molecular features of nonionic detergents involved in the binding kinetics and solubilization efficiency, as studied in model (Langmuir films) and biological (Erythrocytes) membranes.

PubMed

Casadei, Bruna Renata; Domingues, Cleyton Crepaldi; Clop, Eduardo M; Couto, Verônica Muniz; Perillo, Maria Angelica; de Paula, Eneida

2018-06-01

The effect of the nonionic detergents Brij-98 and Brij-58 over human erythrocytes was studied through quantitative hemolysis and in Langmuir films. Hemolytic tests revealed that Brijs are stronger membrane solubilizers than Triton X-100 (TX-100), with effective detergent/lipid ratios of 0.18 and 0.37 for Brij-98 and Brij-58, respectively. Experiments with Langmuir films provided significant information on the kinetics and thermodynamics of detergent-membrane interaction. The adsorption (k a ) and desorption (k d ) rate constants of Brijs were lower than those of TX-100. In the case of k a , that is probably due to their larger hydrophilic head (with twice (20) the oxyethylene units of TX-100). As for the thermodynamic binding constant, the linear and longer hydrophobic acyl chains of Brijs favor their stabilization in-between the lipids, through London van der Waals forces. Consequently, K b,m values of Brij-98 (12,500 M -1 ) and Brij-58 (19,300 M -1 ) resulted higher than TX-100 (7500 M -1 ), in agreement with results from the hemolytic tests. Furthermore, Brij-58 binds with higher affinity than Brij-98 to bilayers and monolayers, despite its shorter (palmitic) hydrocarbon chain, showing that unsaturation restrains the detergent insertion into these environments. Our results provide significant information about the mechanism of interaction between Brijs and membranes, supporting their distinct solubilization effect. Copyright © 2018 Elsevier B.V. All rights reserved.

Molecular Properties of neurotoxin receptors sites associated with sodium channels from mammalian brain.

PubMed

Catterall, W A; Hartshorne, R P; Beneski, D A

1982-01-01

Neurotoxins that act at specific receptor sites on voltage-sensitive sodium channels have been used as molecular probes to identify and purify protein components of sodium channels from mammalian brain. Photoreactive derivatives of scorpion toxin have been prepared and used to covalently label sodium channels in intact synaptosomes. Two polypeptides, alpha with Mr approximately 270,000 and beta with Mr approximately 38,000, are specifically labeled indicating that they are components of the scorpion toxin receptor site on the sodium channel. The sodium channel can be solubilized with retention of specific binding of [3H] saxitoxin using nonionic detergents such as Triton X-100. The solubilized saxitoxin receptor has molecular weight of 316,000 +/- 63,000 and binds 0.9 g of Triton X-100 and phospholipid per g of protein. The solubilized receptor can be purified 750-fold by ion exchange chromatography, wheat germ lectin/Sepharose chromatography and sucrose gradient sedimentation to a final specific activity of 1488 pmol/mg. Analysis of the polypeptide chain composition of the most highly purified fractions indicates that alpha and beta comprise 65% of the protein of these fractions and are only the polypeptides whose presence correlates with saxitoxin binding activity. These studies lead to a working hypothesis of sodium channel structure in which the intact channel is comprised of a complex with Mr of approximately 316,000 containing one mole of alpha (Mr approximately 270,000) and one to three moles of beta (Mr approximately 38,000).

Surfactant titration of nanoparticle-protein corona.

PubMed

Maiolo, Daniele; Bergese, Paolo; Mahon, Eugene; Dawson, Kenneth A; Monopoli, Marco P

2014-12-16

Nanoparticles (NP), when exposed to biological fluids, are coated by specific proteins that form the so-called protein corona. While some adsorbing proteins exchange with the surroundings on a short time scale, described as a "dynamic" corona, others with higher affinity and long-lived interaction with the NP surface form a "hard" corona (HC), which is believed to mediate NP interaction with cellular machineries. In-depth NP protein corona characterization is therefore a necessary step in understanding the relationship between surface layer structure and biological outcomes. In the present work, we evaluate the protein composition and stability over time and we systematically challenge the formed complexes with surfactants. Each challenge is characterized through different physicochemical measurements (dynamic light scattering, ζ-potential, and differential centrifugal sedimentation) alongside proteomic evaluation in titration type experiments (surfactant titration). 100 nm silicon oxide (Si) and 100 nm carboxylated polystyrene (PS-COOH) NPs cloaked by human plasma HC were titrated with 3-[(3-Cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS, zwitterionic), Triton X-100 (nonionic), sodium dodecyl sulfate (SDS, anionic), and dodecyltrimethylammonium bromide (DTAB, cationic) surfactants. Composition and density of HC together with size and ζ-potential of NP-HC complexes were tracked at each step after surfactant titration. Results on Si NP-HC complexes showed that SDS removes most of the HC, while DTAB induces NP agglomeration. Analogous results were obtained for PS NP-HC complexes. Interestingly, CHAPS and Triton X-100, thanks to similar surface binding preferences, enable selective extraction of apolipoprotein AI (ApoAI) from Si NP hard coronas, leaving unaltered the dispersion physicochemical properties. These findings indicate that surfactant titration can enable the study of NP-HC stability through surfactant variation and also selective separation of certain proteins from the HC. This approach thus has an immediate analytical value as well as potential applications in HC engineering.

Cloud point extraction of vanadium in pharmaceutical formulations, dialysate and parenteral solutions using 8-hydroxyquinoline and nonionic surfactant.

PubMed

Khan, Sumaira; Kazi, Tasneem G; Baig, Jameel A; Kolachi, Nida F; Afridi, Hassan I; Wadhwa, Sham Kumar; Shah, Abdul Q; Kandhro, Ghulam A; Shah, Faheem

2010-10-15

A cloud point extraction (CPE) method has been developed for the determination of trace quantity of vanadium ions in pharmaceutical formulations (PF), dialysate (DS) and parenteral solutions (PS). The CPE of vanadium (V) using 8-hydroxyquinoline (oxine) as complexing reagent and mediated by nonionic surfactant (Triton X-114) was investigated. The parameters that affect the extraction efficiency of CPE, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of CPE of V was checked by standard addition method in real samples. The extracted surfactant-rich phase was diluted with nitric acid in ethanol, prior to subjecting electrothermal atomic absorption spectrometry. Under these conditions, the preconcentration of 50 mL sample solutions, allowed raising an enrichment factor of 125-fold. The lower limit of detection obtained under the optimal conditions was 42 ng/L. The proposed method has been successfully applied to the determination of trace quantity of V in various pharmaceutical preparations with satisfactory results. The concentration ranges of V in PF, DS and PS samples were found in the range of 10.5-15.2, 0.65-1.32 and 1.76-6.93 microg/L, respectively. 2010 Elsevier B.V. All rights reserved.

Effect of Cerium(III) and ionic liquids on the clouding behavior of Triton X-100 micelles

NASA Astrophysics Data System (ADS)

Sen, Indrani Das; Negi, Charu; Jayaram, Radha V.

2018-04-01

In the present study, the effect of Ce(III) on the clouding behavior of Triton X-100 has been investigated in the presence and absence of imidazolium based ionic liquids of varying chain length and counter ions. Thermodynamic parameters of clouding were calculated to comprehend the underlying interactions between the surfactant and the additives. The cloud point (CP) of Triton X-100 was found to increase with the concentration of Ce(III) and that of the ionic liquids studied. This increase of CP reflects the solubilization of the ionic liquids in the micellar solution1.

Effect of Decellularization Protocol on the Mechanical Behavior of Porcine Descending Aorta

PubMed Central

Fitzpatrick, John C.; Clark, Peter M.; Capaldi, Franco M.

2010-01-01

Enzymatic-detergent decellularization treatments may use a combination of chemical reagents to reduce vascular tissue to sterilized scaffolds, which may be seeded with endothelial cells and implanted with a low risk of rejection. However, these chemicals may alter the mechanical properties of the native tissue and contribute to graft compliance mismatch. Uniaxial tensile data obtained from native and decellularized longitudinal aortic tissue samples was analyzed in terms of engineering stress and fit to a modified form of the Yeoh rubber model. One decellularization protocol used SDS, while the other two used TritonX-100, RNase-A, and DNase-I in combination with EDTA or sodium-deoxycholate. Statistical significance of Yeoh model parameters was determined by paired t-test analysis. The TritonX-100/EDTA and 0.075% SDS treatments resulted in relatively variable mechanical changes and did not effectively lyse VSMCs in aortic tissue. The TritonX-100/sodium-deoxycholate treatment effectively lysed VSMCs and was characterized by less variability in mechanical behavior. The data suggests a TritonX-100/sodium-deoxycholate treatment is a more effective option than TritonX-100/EDTA and SDS treatments for the preparation of aortic xenografts and allografts because it effectively lyses VSMCs and is the least likely treatment, among those considered, to promote a decrease in mechanical compliance. PMID:20689621

Diagnostic performances of clinical laboratory tests using Triton X-100 to reduce the biohazard associated with routine testing of Ebola virus-infected patients.

PubMed

Tempestilli, Massimo; Pucci, Luigia; Notari, Stefania; Di Caro, Antonino; Castilletti, Concetta; Rivelli, Maria Rosaria; Agrati, Chiara; Pucillo, Leopoldo Paolo

2015-11-01

Ebola virus, an enveloped virus, is the cause of the largest and most complex Ebola virus disease (EVD) outbreak in West Africa. Blood or body fluids of an infected person may represent a biohazard to laboratory workers. Laboratory tests of virus containing specimens should be conducted in referral centres at biosafety level 4, but based on the severity of clinical symptoms, basic laboratories might be required to execute urgent tests for patients suspected of EVD. The aim of this work was to compare the analytical performances of laboratory tests when Triton X-100, a chemical agent able to inactivate other enveloped viruses, was added to specimens. Results of clinical chemistry, coagulation and haematology parameters on samples before and after the addition of 0.1% (final concentration) of Triton X-100 and 1 h of incubation at room temperature were compared. Overall, results showed very good agreement by all statistical analyses. Triton X-100 at 0.1% did not significantly affect the results for the majority of the analytes tested. Triton X-100 at 0.1% can be used to reduce the biohazard in performing laboratory tests on samples from patients with EVD without affecting clinical decisions.

Membrane fouling and wetting in membrane distillation and their mitigation by novel membranes with special wettability.

PubMed

Wang, Zhangxin; Lin, Shihong

2017-04-01

Membrane distillation (MD) has been identified as a promising technology to desalinate the hypersaline wastewaters from fracking and other industries. However, conventional hydrophobic MD membranes are highly susceptible to fouling and/or wetting by the hydrophobic and/or amphiphilic constituents in these wastewaters of complex compositions. This study systematically investigates the impact of the surface wetting properties on the membrane wetting and/or fouling behaviors in MD. Specifically, we compare the wetting and fouling resistance of three types of membranes of different wetting properties, including hydrophobic and omniphobic membranes as well as composite membranes with a hydrophobic substrate and a superhydrophilic top surface. We challenged the MD membranes with hypersaline feed solutions that contained a relatively high concentration of crude oil with and without added synthetic surfactants, Triton X-100. We found that the composite membranes with superhydrophilic top surface were robustly resistant to oil fouling in the absence of Triton X-100, but were subject to pore wetting in the presence of Triton X-100. On the other hand, the omniphobic membranes were easily fouled by oil-in-water emulsion without Triton X-100, but successfully sustained stable MD performance with Triton X-100 stabilized oil-in-water emulsion as the feed solution. In contrast, the conventional hydrophobic membranes failed readily regardless whether Triton X-100 was present, although via different mechanisms. These findings are corroborated by contact angle measures as well as oil-probe force spectroscopy. This study provides a holistic picture regarding how a hydrophobic membrane fails in MD and how we can leverage membranes with special wettability to prevent membrane failure in MD operations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Endocytosis of GPI-linked membrane folate receptor-alpha

PubMed Central

1996-01-01

GPI-linked membrane folate receptors (MFRs) have been implicated in the receptor-mediated uptake of reduced folate cofactors and folate-based chemotherapeutic drugs. We have studied the biosynthetic transport to and internalization of MFR isoform alpha in KB-cells. MFR-alpha was synthesized as a 32-kD protein and converted in a maturely glycosylated 36-38-kD protein 1 h after synthesis. 32-kD MFR-alpha was completely soluble in Triton X-100 at 0 degree C. In contrast, only 33% of the 36- 38-kD species could be solubilized at these conditions whereas complete solubilization was obtained in Triton X-100 at 37 degrees C or in the presence of saponin at 0 degree C. Similar solubilization characteristics were found when MFR-alpha at the plasma membrane was labeled with a crosslinkable 125I-labeled photoaffinity-analog of folic acid as a ligand. Triton X-100-insoluble membrane domains containing MFR-alpha could be separated from soluble MFR-alpha on sucrose flotation gradients. Only Triton X-100 soluble MFR-alpha was internalized from the plasma membrane. The reduced-folate-carrier, an integral membrane protein capable of translocating (anti-)folates across membranes, was completely excluded from the Triton X-100- resistant membrane domains. Internalized MFR-alpha recycled slowly to the cell surface during which it remained soluble in Triton X-100 at 0 degree C. Using immunoelectron microscopy, we found MFR-alpha along the entire endocytic pathway: in clathrin-coated buds and vesicles, and in small and large endosomal vacuoles. In conclusion, our data indicate that a large fraction, if not all, of internalizing MFR-alpha bypasses caveolae. PMID:8567728

Endocytosis of GPI-linked membrane folate receptor-alpha.

PubMed

Rijnboutt, S; Jansen, G; Posthuma, G; Hynes, J B; Schornagel, J H; Strous, G J

1996-01-01

GPI-linked membrane folate receptors (MFRs) have been implicated in the receptor-mediated uptake of reduced folate cofactors and folate-based chemotherapeutic drugs. We have studied the biosynthetic transport to and internalization of MFR isoform alpha in KB-cells. MFR-alpha was synthesized as a 32-kD protein and converted in a maturely glycosylated 36-38-kD protein 1 h after synthesis. 32-kD MFR-alpha was completely soluble in Triton X-100 at 0 degree C. In contrast, only 33% of the 36-38-kD species could be solubilized at these conditions whereas complete solubilization was obtained in Triton X-100 at 37 degrees C or in the presence of saponin at 0 degree C. Similar solubilization characteristics were found when MFR-alpha at the plasma membrane was labeled with a crosslinkable 125I-labeled photoaffinity-analog of folic acid as a ligand. Triton X-100-insoluble membrane domains containing MFR-alpha could be separated from soluble MFR-alpha on sucrose flotation gradients. Only Triton X-100 soluble MFR-alpha was internalized from the plasma membrane. The reduced-folate-carrier, an integral membrane protein capable of translocating (anti-)folates across membranes, was completely excluded from the Triton X-100-resistant membrane domains. Internalized MFR-alpha recycled slowly to the cell surface during which it remained soluble in Triton X-100 at 0 degree C. Using immunoelectron microscopy, we found MFR-alpha along the entire endocytic pathway: in clathrin-coated buds and vesicles, and in small and large endosomal vacuoles. In conclusion, our data indicate that a large fraction, if not all, of internalizing MFR-alpha bypasses caveolae.

Spectrofluorimetric study on the inclusion interaction between vitamin K3 with p-(p-sulfonated benzeneazo)calix[6]arene and determination of VK3.

PubMed

Zhou, Yunyou; Xu, Hongwei; Wu, Lian; Liu, Chun; Lu, Qin; Wang, Lun

2008-11-15

The characteristics of host-guest complexation between p-(p-sulfonated benzeneazo) calix[6]arene (SBC6A) and vitamin K3 (VK3) were investigated by fluorescence spectrometry. A 1:1 stoichiometry for the complexation was established and was verified by Job's plot. An association constant of 4.95 x 10(3)L mol(-1) at 20 degrees C was calculated by applying a deduced equation. The interaction mechanism of the inclusion complex was discussed. It was found that the fluorescence of SBC6A could be remarkably quenched by an appropriate amount of VK3 especially when non-ionic surfactant Triton X-100 existed. According to the obtained results, a novel sensitive spectrofluorimetric method for the determination of VK3 based on supramolecular complex was developed with a linear range of 5.0 x 10(-7) -3.0 x 10(-5)mol L(-1) and a detection limit of 2.0 x 10(-7)mol L(-1). The proposed method was used to determine VK3 in commercial preparations with satisfactory results.

Effect of amphiphilic polyurethane nanoparticles on sorption-desorption of phenanthrene in aquifer material.

PubMed

Kim, Ju-Young; Shim, Sun-Bo; Shim, Jin-Kie

2003-03-17

Micelle-like amphiphilic nano-sized polyurethane (APU) nanoparticles were synthesized via chemical cross-linking reaction of nano-aggregates of urethane acrylate nonionomer (UAN) chain and were tested for extraction efficiency of sorbed phenanthrene from aquifer material. Even though the solubilizing performance and interfacial activity of APU nanoparticles were inferior to that of Triton X-100, in the low concentration region, APU nanoparticles could effectively reduce phenanthrene sorption on the aquifer material and extracted sorbed phenanthrene from the aquifer material, whereas Triton X-100 could not extract sorbed phenanthrene and rather increased phenanthrene sorption onto the aquifer materials. At higher concentrations, APU nanoparticles and Triton X-100 had almost the same soil washing effectiveness. This interesting result is mainly due to a lower degree of sorption of APU nanoparticles onto the aquifer material. The sorption of APU nanoparticles onto aquifer sand is largely hindered by their chemically cross-linked nature, resulting in better soil-washing performance of APU nanoparticles than Triton X-100. Copyright 2003 Elsevier Science B.V.

Asymmetrical flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry for sizing SeNPs for packaging applications

NASA Astrophysics Data System (ADS)

Palomo-Siguero, María; Vera, Paula; Echegoyen, Yolanda; Nerin, Cristina; Cámara, Carmen; Madrid, Yolanda

2017-06-01

This paper describes the application of Asymmetrical Flow Field-Flow Fractionation (AF4) coupled to diode array detector (DAD) and inductively coupled plasma mass spectrometry (AF4-UV-ICP-MS) to characterize selenium nanoparticles (SeNPs) in an aqueous acrylic adhesive to be used in a multilayer food packaging material. SeNPs were synthesized using a solution-phase approach based on the reduction of selenite with ascorbic acid in presence of different stabilizers compatible with food industry such as polysaccharides (chitosan (poly(D-glucosamine) and hydroxyethylcellulose (HEC)) and non-ionic surfactants (Triton X-100 (t-octylphenoxypolyethoxyethanol), 2,4,7,9-tetramethyl 5decyne-4,7-diol ethoxylate, and isotridecanol ethoxylate). Several parameters such as pH, ascorbic acid and stabilizers concentration, and compatibility of the stabilizer with the adhesive were evaluated. SeNPs suspensions with spherical morphology were obtained except when isotridecanol ethoxylate was employed which provides SeNPs with a nanorod morphology. AF4-DAD-ICP-MS was further applied for sizing the different SeNPs preparations. DAD was used as detector for selecting the best AF4 separation conditions before coupling to ICP-MS to ensure unequivocal identification of NPs. AF4 calibration with polystyrene latex (PSL) beads of known sizes allowed size determination of the different SeNPs. The following estimated hydrodynamic sizes (expressed as the mean ± standard deviation, n = 6 replicates) were found: chitosan-SeNPs- (26 ± 3 nm), TritonX100-SeNPs (22 ± 10 nm) HEC- SeNPs (91 ± 8 nm) and 2,4,7,9-tetramethyl 5decyne-4,7-diol ethoxylate- SeNPs (59 ± 4 nm). The proposed methodology was successfully applied to the characterization in terms of size of aqueous acrylic adhesives containing SeNPs Results from AF4-ICP-MS and TEM shown that only those SeNPs obtained with non-ionic surfactants and HEC were compatible with the adhesive. The results reported here evidence the usefulness of AF4-ICP-MS as analytical tool for controlling those manufacturing process involving nanoparticles which opens new frontiers in applicability of AF4-ICP-MS.

Fluorophotometric determination of critical micelle concentration (CMC) of ionic and non-ionic surfactants with carbon dots via Stokes shift.

PubMed

Lavkush Bhaisare, Mukesh; Pandey, Sunil; Shahnawaz Khan, M; Talib, Abou; Wu, Hui-Fen

2015-01-01

A new and facile method for the determination of critical micelle concentration (CMC) of ionic and non-ionic surfactants is proposed in this article. Carbon dots exhibited substantial fluorescence and therefore enhanced the sensitivity of this evaluation. Understanding the formation of surfactant micelles is vital for the applications of biomedicine such as drug fabrication and smart molecular vehicles in delivering therapeutic dosage to various molecular sites. The fluorescence property of carbon dots was utilized for the first time to estimate the critical micelle concentration of surfactants. The central concept of the approach is based on the Stokes shift determination of a system composed of constant amount of carbon dots with varying concentrations of ionic and non-ionic surfactants. The synthesized carbon dots were characterized by FTIR, TEM, XRD, Raman, UV, and fluorescence spectroscope. The carbon dots were excited at 280 nm so as to obtain maximum emission for the Stokes shift measurement. The CMC value of cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS), Triton X-100, dodecyldimethyl(3-sulfopropyl)ammonium hydroxide (SB-12) evaluated by this approach was found to be 0.98, 7.3, 0.19, and 3.5mM, respectively. The signals of spectra were assigned and explained in terms of both electron transitions between specific molecular orbital and the interaction with solvent. Copyright © 2014 Elsevier B.V. All rights reserved.

Molecular basis of interactions between mitochondrial proteins and hydroxyapatite in the presence of Triton X-100, as revealed by proteomic and recombinant techniques.

PubMed

Yamamoto, Takenori; Tamaki, Haruna; Katsuda, Chie; Nakatani, Kiwami; Terauchi, Satsuki; Terada, Hiroshi; Shinohara, Yasuo

2013-08-02

Hydroxyapatite chromatography is a very important step in the purification of voltage-dependent anion channels (VDACs) and several members of solute carrier family 25 (Slc25) from isolated mitochondria. In the presence of Triton X-100, VDACs and Slc25 members present a peculiar property, i.e., a lack of interaction with hydroxyapatite, resulting in their presence in the flow-through fraction of hydroxyapatite chromatography. This property has allowed selective isolation of VDACs and Slc25 members from a mixture of total mitochondrial proteins. However, the reason why only these few proteins are selectively obtained in the presence of Triton X-100 from the flow-though fraction of hydroxyapatite chromatography has not yet been adequately understood. In this study, when we examined the protein species in the flow-through fractions by proteomic analysis, VDAC isoforms, Slc25 members, and some other membrane proteins were identified. All the mitochondrial proteins had in common high hydrophobicity over their entire protein sequences. When the proteins were fused to soluble proteins, the fused proteins showed affinity for hydroxyapatite even in the presence of Triton X-100. Based on these results, we discussed the molecular basis of the interactions between proteins and hydroxyapatite in the presence of Triton X-100. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of Small Intestine Grafts Decellularization Methods for Corneal Tissue Engineering

PubMed Central

Oliveira, Ana Celeste; Garzón, Ingrid; Ionescu, Ana Maria; Carriel, Victor; Cardona, Juan de la Cruz; González-Andrades, Miguel; Pérez, María del Mar; Alaminos, Miguel; Campos, Antonio

2013-01-01

Advances in the development of cornea substitutes by tissue engineering techniques have focused on the use of decellularized tissue scaffolds. In this work, we evaluated different chemical and physical decellularization methods on small intestine tissues to determine the most appropriate decellularization protocols for corneal applications. Our results revealed that the most efficient decellularization agents were the SDS and triton X-100 detergents, which were able to efficiently remove most cell nuclei and residual DNA. Histological and histochemical analyses revealed that collagen fibers were preserved upon decellularization with triton X-100, NaCl and sonication, whereas reticular fibers were properly preserved by decellularization with UV exposure. Extracellular matrix glycoproteins were preserved after decellularization with SDS, triton X-100 and sonication, whereas proteoglycans were not affected by any of the decellularization protocols. Tissue transparency was significantly higher than control non-decellularized tissues for all protocols, although the best light transmittance results were found in tissues decellularized with SDS and triton X-100. In conclusion, our results suggest that decellularized intestinal grafts could be used as biological scaffolds for cornea tissue engineering. Decellularization with triton X-100 was able to efficiently remove all cells from the tissues while preserving tissue structure and most fibrillar and non-fibrillar extracellular matrix components, suggesting that this specific decellularization agent could be safely used for efficient decellularization of SI tissues for cornea TE applications. PMID:23799114

Manifestation of cryptic fibroblast tissue factor occurs at detergent concentrations which dissolve the plasma membrane.

PubMed

Carson, S D

1996-04-01

Cultured fibroblasts treated with increasing concentrations of detergents expressed only encrypted levels of tissue factor activity (measured by fX activation in the presence of fVIIa), characteristic of undamaged cells, until each detergent reached a critical concentration at which the cryptic tissue factor activity was manifested. Beyond the narrow ranges of concentrations over which the detergents stimulated tissue factor activity, the detergents were inhibitory. Studies with Triton X-100 and octyl glucoside revealed that manifestation of tissue factor activity coincided with breakdown of the plasma membrane. The magnitude of the increased tissue factor activity differed among detergents, with octyl glucoside giving the largest response. The tissue factor that was active after Triton X-100 treatment remained mostly associated with the insoluble cell residue, whereas the concentration of octyl glucoside which stimulated activity released tissue factor activity into the supernatant. Radiolabeled antibody against human tissue factor was used to show that a small percentage of the total accessible tissue factor remained in the insoluble fraction after treatment with either non-ionic detergent. Chromatographic analysis of lipids extracted from cells treated with detergents and dansyl chloride showed dansyl-reactivity of phosphatidylserine on intact cells, and solubilization of membrane lipids at sublytic concentrations of detergents. These findings reveal that there is a critical level of detergent-induced membrane damage at which tissue factor activity is maximally expressed, in essentially an all-or-none manner. The results are consistent with a major role for phospholipid asymmetry in regulation of tissue factor specific activity, but require either maintenance of asymmetry during sublytic detergent perturbation of the plasma membrane or additional control mechanisms.

Temperature-dependent magnetic field effect study on exciplex luminescence: probing the triton X-100 reverse micelle in cyclohexane.

PubMed

Das, Doyel; Nath, Deb Narayan

2007-09-20

The microenvironment within the reverse micelle of the nonionic surfactant Triton X-100 (TX-100) in cyclohexane has been investigated by studying the magnetic field effect (MFE) on pyrene-dimethylaniline exciplex luminescence. The nature of exciplex fluorescence and its behavior in the presence of a magnetic field have been found to vary significantly with the water content of the medium. Results are discussed in light of multiple exciplex formation within the micelle which is further supported by the fluorescence lifetime measurements. Those exciplexes emitting at longer wavelength are found to be magnetic field sensitive while those emitting toward the blue region of the spectrum are insensitive toward magnetic field. Since the exciplex's emission characteristics and magnetic field sensitivity depend on its immediate surrounding, it has been concluded that the environment within the micelle is nonuniform. With an increase in hydration level, different zones of varying polarity are created within the reverse micelle. It has been pointed out that the magnetic field sensitive components reside inside the polar core of the micelle while those located near the hydrocarbon tail are field insensitive. However it has been presumed that an interconversion between the different types of exciplexes is possible. The environment within the reverse micelle is found to be largely affected by the change in temperature, and this is reflected in the exciplex emission property and the extent of magnetic field effect. Interestingly, the variation of MFE with temperature follows different trends in the dry and the wet reverse micelle. A comparison has been drawn with the reverse micelle of the ionic surfactant to get an insight into the difference between the various types of micellar environment.

Preliminary characterization of Thy-1.1 and Ag-B antigens from rat tissues solubilized in detergents

PubMed Central

Letarte-Muirhead, Michelle; Acton, Ronald T.; Williams, Alan F.

1974-01-01

1. A radioactive binding assay for Thy-1.1 alloantigen which functions in the presence of detergents was established by using glutaraldehyde-fixed thymocytes as target cells. Thy-1.1 activity in detergent extracts was then assayed by measuring inhibition of the binding assay. 2. Solubilization of Thy-1.1 from whole thymocytes, and their membranes by a large number of non-ionic detergents and deoxycholate was studied. In the same extracts Ag-B(4) histocompatibility antigenic activities were measured. With the exception of Nonidet P-40, the detergents did not affect the antigenicity of Thy-1.1, but only Lubrol-PX and deoxycholate gave effective solubilization as measured by activity remaining in the supernatant after centrifugation at 200000g for 40min. With Ag-B(4) antigen, Triton X-100, Triton X-67 and Nonidet P-40 gave effective solubilization as well as Lubrol-PX and deoxycholate. Solubilization of Thy-1.1 activity from leukaemia cells and a brain homogenate was also studied, but none of the non-ionic detergents gave satisfactory results with these tissues. 3. Extracts from thymocyte membranes were further examined by gel filtration and sucrose gradient centrifugation. The Thy-1.1 activity behaved as a single component in deoxycholate with a density similar to that of a globular protein, but in Lubrol-PX the antigen was contained in a low-density complex. In Lubrol-PX extracts Ag-B(4) was also found in aggregates not observed in deoxycholate. 4. The s20,w values for Thy-1.1 and Ag-B(4) antigens in deoxycholate were 2.4 and 4.4, and v̄ values were 0.70 and 0.75 respectively. The Stokes radius observed for Thy-1.1 was 3.1nm and for Ag-B(4) 5.3nm. By using these values the molecular weights for the antigen–detergent complexes were calculated to be 28000 for Thy-1.1 and 100000 for Ag-B(4). PMID:4219284

HPTLC method for the simultaneous determination of four indole alkaloids in Rauwolfia tetraphylla: a study of organic/green solvent and continuous/pulse sonication.

PubMed

Gupta, Shikha; Shanker, Karuna; Srivastava, Santosh K

2012-07-01

A new validated high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous quantitation of four antipsychotic indole alkaloids (IAs), reserpiline (RP, 1), α-yohimbine (YH, 2), isoreserpiline (IRP, 3) and 10-methoxy tetrahydroalstonine (MTHA, 4) as markers in the leaves of Rauwolfia tetraphylla. Extraction efficiency of the targeted IAs from the leaf matrix with organic and ecofriendly (green) solvents using percolation, ultrasonication and microwave techniques were studied. Non-ionic surfactants, viz. Triton X-100, Triton X-114 and Genapol X-80 were used for extraction and no back-extraction or liquid chromatographic steps were used to remove the targeted IAs from the surfactant-rich extractant phase. The optimized cloud point extraction was found a potentially useful methodology for the preconcentration of the targeted IAs. The separation was achieved on silica gel 60F(254) HPTLC plates using hexane-ethylacetate-methanol (5:4:1, v/v/v) as mobile phase. The quantitation of IAs (1-4) was carried out using the densitometric reflection/absorption mode at 520 nm after post chromatographic derivatization using Dragendorff's reagent. The method was validated for peak purity, precision, accuracy, robustness, limit of detection (LOD) and quantitation (LOQ). Method specificity was confirmed using retention factor (R(f)) and visible spectral (post chromatographic scan) correlation of marker compounds in the samples and standard tracks. Copyright © 2012 Elsevier B.V. All rights reserved.

The adsorption properties of short chain alcohols and Triton X-100 mixtures at the water-air interface.

PubMed

Zdziennicka, Anna

2009-07-15

The adsorption behaviour at the water-air interface of aqueous solutions of Triton X-100 and methanol (ethanol) mixtures at constant Triton X-100 (TX-100) concentration equal to 10(-7), 10(-6), 10(-5), 10(-4), 6x10(-4) and 10(-3)M, respectively, in a wide range of alcohol concentration was investigated by surface tension measurements of solutions. The obtained values of the surface tension of aqueous solutions of "pure" methanol and ethanol and their mixtures with TX-100, as well as the values of propanol solutions and their mixtures with TX-100 as a function of alcohol concentration taken from the literature were compared with those calculated from the Szyszkowski, Connors and Fainerman and Miller equations. On the basis of this comparison it was stated that these equations can be useful for description of the solution surface tension in the wide range of alcohol concentration, but only at the concentrations of Triton X-100 corresponding to its unsaturated layer in the absence of alcohol. It was also stated that the Connors equation is more adequate for concentrated aqueous organic solutions. The measured values of the surface tension were used in the Gibbs equation to determine the surface excess concentration of Triton X-100 and alcohol. Next, on the basis of Gibbs adsorption isotherms those of Guggenheim and Adam and real adsorption isotherms were established. From the obtained adsorption isotherms it results that alcohol influences the shape of TX-100 isotherms in the whole range of alcohol and TX-100 concentration, but TX-100 influences the alcohol isotherms only at TX-100 concentration at which the saturated monolayer at the solution-air interface is formed in the absence of alcohol. This conclusion was confirmed by analysis of the composition of the surface layer in comparison to the composition of the bulk phase in the equilibrium state.

Remediation of soil-bound polynuclear aromatic hydrocarbons using nonionic surfactants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeom, IckTae; Ghosh, Mriganka; Cox, C.

1996-12-31

The solubilization and biodegradation of soil-bound PAHs from a manufactured gas plant (MGP) site soil was investigated using surfactants. Three nonionic polyoxyethylene (POE) surfactants, Triton X-100, Tween 80, and Brij 35, were used. The fate of four PAHs, phenanthrene, anthracene, pyrene, and benzo(a)pyrene were monitored during the remediation process. The measured concentrations of solubilized PAHs agreed well with those estimated using micelle-water partitioning coefficient, K{sub m}, and Raoult`s law. The solubilization of soil-bound PAHs by surfactants is a slow, nonequilibrium process. Diffusion of PAH molecules within the weathered soil-tar matrix is proposed as the rate-limiting step in solubilizing PAHs frommore » such soils. A radial diffusion model is used to describe solubilization of PAHs by surfactant washing. The model predicts experimental results fairly well at low surfactant dosages while at high dosages it somewhat overestimates the extent of solubilization. Biodegradation studies were performed using a natural consortium of microorganisms enriched from PAH-contaminated soils. Surfactants enhanced biodegradation of PAHs except for Tween 80. However, biodegradation of surfactants themselves appear to attenuate the beneficial effects of surfactant-mediated bioremediation.« less

Development of a cloud point extraction and spectrophotometry-based microplate method for the determination of nitrite in human urine and blood.

PubMed

Zhao, Jiao; Lu, Yunhui; Fan, Chongyang; Wang, Jun; Yang, Yaling

2015-02-05

A novel and simple method for the sensitive determination of trace amounts of nitrite in human urine and blood has been developed by combination of cloud point extraction (CPE) and microplate assay. The method is based on the Griess reaction and the reaction product is extracted into nonionic surfactant Triton-X114 using CPE technique. In this study, decolorization treatment of urine and blood was applied to overcome the interference of matrix and enhance the sensitivity of nitrite detection. Multi-sample can be simultaneously detected thanks to a 96-well microplate technique. The effects of different operating parameters such as type of decolorizing agent, concentration of surfactant (Triton X-114), addition of (NH4)2SO4, extraction temperature and time, interfering elements were studied and optimum conditions were obtained. Under the optimum conditions, a linear calibration graph was obtained in the range of 10-400 ng mL(-1) of nitrite with limit of detection (LOD) of 2.5 ng mL(-1). The relative standard deviation (RSD) for determination of 100 ng mL(-1) of nitrite was 2.80%. The proposed method was successfully applied for the determination of nitrite in the urine and blood samples with recoveries of 92.6-101.2%. Copyright © 2014 Elsevier B.V. All rights reserved.

Determination of rhodium in metallic alloy and water samples using cloud point extraction coupled with spectrophotometric technique.

PubMed

Kassem, Mohammed A; Amin, Alaa S

2015-02-05

A new method to estimate rhodium in different samples at trace levels had been developed. Rhodium was complexed with 5-(4'-nitro-2',6'-dichlorophenylazo)-6-hydroxypyrimidine-2,4-dione (NDPHPD) as a complexing agent in an aqueous medium and concentrated by using Triton X-114 as a surfactant. The investigated rhodium complex was preconcentrated with cloud point extraction process using the nonionic surfactant Triton X-114 to extract rhodium complex from aqueous solutions at pH 4.75. After the phase separation at 50°C, the surfactant-rich phase was heated again at 100°C to remove water after decantation and the remaining phase was dissolved using 0.5mL of acetonitrile. Under optimum conditions, the calibration curve was linear for the concentration range of 0.5-75ngmL(-1) and the detection limit was 0.15ngmL(-1) of the original solution. The enhancement factor of 500 was achieved for 250mL samples containing the analyte and relative standard deviations were ⩽1.50%. The method was found to be highly selective, fairly sensitive, simple, rapid and economical and safely applied for rhodium determination in different complex materials such as synthetic mixture of alloys and environmental water samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Incapacity of Response to Disulfide-Reducing Agent in Triton X-100-Treated Oocytes of Starfish, Asterina pectinifera

NASA Astrophysics Data System (ADS)

Mita, Masatoshi

2005-04-01

Resumption of meiosis in starfish oocytes is induced by the natural maturation-inducing hormone, 1-methyladenine (1-MeAde). Oocyte maturation is also induced by the disulfide-reducing agent, dithiothreitol (DTT). Previous studies have shown that 1-MeAde controls meiosis by interacting with its receptors, which are located exclusively on oocyte plasma membrane. However, little is known about the mechanism of oocyte maturation induced by DTT. Thus, this study examined whether DTT interacts with 1-MeAde receptors to induce oocyte maturation. When oocytes were treated with Triton X-100, they failed to respond to 1-MeAde and DTT. Although the Triton X-100-treated oocytes recovered the capacity to respond to 1-MeAde during incubation in seawater, they remained unresponsive to DTT during seawater incubations. These results suggest that DTT does not interact with 1-MeAde receptors to induce oocyte maturation in starfish. It is possible that a protein essential for mediating DTT-induced maturation is eliminated from the oocytes surface following Triton X-100 treatment.

ABC-transporters are localized in caveolin-1-positive and reggie-1-negative and reggie-2-negative microdomains of the canalicular membrane in rat hepatocytes.

PubMed

Ismair, Manfred G; Häusler, Stephanie; Stuermer, Claudia A; Guyot, Christelle; Meier, Peter J; Roth, Jürgen; Stieger, Bruno

2009-05-01

The canalicular plasma membrane is constantly exposed to bile acids acting as detergents. Bile acids are essential to mediate release of biliary lipids from the canalicular membrane. Membrane microdomains (previously called lipid rafts) are biochemically defined by their resistance to detergent solubilization at cold temperature. We aimed to investigate the canalicular plasma membrane for the presence of microdomains, which could protect this membrane against the detergent action of bile acids. Highly purified rat liver canalicular plasma membrane vesicles were extracted with 1% Triton X-100 or 1% Lubrol WX at 4 degrees C and subjected to flotation through sucrose step gradients. Both detergents yielded detergent-resistant membranes containing the microdomain markers alkaline phosphatase and sphingomyelin. However, cholesterol was resistant to Lubrol WX solubilization, whereas it was only marginally resistant to solubilization by Triton X-100. The microdomain marker caveolin-1 was localized to the canalicular plasma membrane domain and was resistant to Lubrol WX, but to a large extent solubilized by Triton X-100. The two additional microdomain markers, reggie-1 and reggie-2, were localized to the basolateral and canalicular plasma membrane and were partially resistant to Lubrol WX but resistant to Triton X-100. The canalicular transporters bile salt export pump, multidrug resistance protein 2, multidrug resistance-associated protein 2, and Abcg5 were largely resistant to Lubrol WX but were solubilized by Triton X-100. These results indicate the presence of two different types of microdomains in the canalicular plasma membrane: "Lubrol-microdomains" and "Triton-microdomains". "Lubrol-microdomains" contain the machinery for canalicular bile formation and may be the starting place for canalicular lipid secretion.

Effects of detergents on the properties of 4-hydroxybenzoate. Polyprenyl transferase and the specificity of the polyprenyl pyrophosphate synthetic system in mitochondria.

PubMed

Nishino, T; Rudney, H

1977-02-22

The properties of 4-hydroxybenzoate:polyprenyl transferase and the system synthesizing polyprenyl pyrophosphate have been studied in mitochondria from rat and guinea pig livers. With solanesyl pyrophosphate and 4-hydroxybenzoate as substrates the formation of 3-nonaprenyl-4-hydroxybenzoate was linear with time, concentration of protein, and concentration of solanesyl pyrophosphate. Solanesyl monophosphate is inactive as a substrate and is noninhibitory. Conversion of solanesyl monophosphate to the pyrophosphate could not be detected. Detergents such as Triton X-100, Tween-80, and sodium deoxycholate activated the enzyme in mitochondria which were aged by freezing at -20 degrees C for periods ranging from 1 h to several days. Maximum activation also required Mg2+. In agreement with previous observation the effect of Mg2+ and Triton X-100 on fresh mitochondria was quite variable; however, activation with aged preparations was very consistent. Treatment with TritonX-100 causes al alteration in the biosynthetic pattern of rat liver mitochondria so that rather than nonaprenyl, decaprenyl, pyrophosphate is preferentially made in the presence of solanesyl pyrophosphate and isopentenyl pyrophosphate. In the presence of Triton X-100 and added pool of solanesyl pyrophosphate appears to exert a feedback inhibition on the incorporation of isopentenyl pyrophosphate into solanesyl pyrophosphate. In the case of guinea pig liver mitochondria a different pattern is observed with Triton X-100 in contrast to the rat. The de novo formation of decaprenyl pyrophosphate from isopentenyl pyrophosphate appears to be inhibited by Triton X-100, but the synthesis of decaprenyl pyrophosphate from isopentenyl pyrophosphate and nonaprenyl pyrophosphate is not inhibited. The data also indicate that in guinea pig liver in a system synthesizing decaprenyl pyrophosphate from isopentenyl pyrophosphate, there does not appear to be a detectable pool of nonaprenyl pyrophosphate. These results show that detergents can affect the specificity of the mitochondrial system synthesizing polyprenyl pyrophosphates.

The structure of interfibrillar proteoglycan bridges (‘shape modules’) in extracellular matrix of fibrous connective tissues and their stability in various chemical environments

PubMed Central

SCOTT, JOHN E.; THOMLINSON, ALISON M.

1998-01-01

Collagen fibrils in extracellular matrices of connective tissues (tendon, cornea, etc.) are bridged and linked by the anionic glycosaminoglycans (AGAGs) of the small proteoglycans (decoron, etc.). It was proposed that these bridges and ties maintain the collagen fibril dispositions in relation to each other, helping to define tissue shape, and hence called shape modules. This investigation describes chemical and physicochemical conditions in which these structures are stable and what treatments cause their disruption. The effects on fixed and unfixed sections of tendon, cornea, lung and ear from rat, mouse and rabbit of pH, electrolyte concentration, EDTA, mercaptoethanol, hydrogen peroxide, free radicals, periodate, acetylation, urea, nonionic detergent and organic solvents were assessed by staining with Cupromeronic blue or Alcec blue in CEC techniques to localise AGAG bridges or their disintegration products. Ca2+ was not involved in the structures, oxidation/reduction had no effect and Triton X100, a nonionic detergent did not damage them. They were stable between pH 4.5 and 9.5. Periodate as a glycol-cleaving reagent did not affect them. High concentrations of urea (>2.0 m) and MgCl2 (0.5 m) disrupted the tissues. The combination of Triton and urea at concentrations too low to cause damage separately was disruptive. Free radicals in periodate solutions were damaging. Organic solvents caused collapse and rearrangements of the AGAG filaments. Acetylation caused considerable disruption of shape modules. Dermochondan but not keratan sulphate AGAGs were removed by treatment with NaOH. After fixing with glutaraldehyde only free radical and NaOH treatments were severely disruptive of shape modules. The results are compatible with a previously proposed structure for the shape modules, stabilised by hydrophobic and hydrogen bonding. PMID:9688505

Probing dynamics and mechanism of exchange process of quaternary ammonium dimeric surfactants, 14-s-14, in the presence of conventional surfactants.

PubMed

Liu, Jun; Jiang, Yan; Chen, Hong; Mao, Shi Zhen; Du, You Ru; Liu, Mai Li

2012-12-27

In this Article, we investigated effects of different types of conventional surfactants on exchange dynamics of quaternary ammonium dimeric surfactants, with chemical formula C(14)H(29)N(+)(CH(3))(2)- (CH(2))(s)-N(+)(CH(3))(2)C(14)H(29)·2Br(-), or 14-s-14 for short. Two nonionic surfactants, TritonX-100 (TX-100) and polyethylene glycol (23) laurylether (Brij-35), and one cationic surfactant, n-tetradecyltrimethyl ammonium bromide (TTAB), and one ionic surfactant, sodium dodecyl sulfate (SDS) were chosen as typical conventional surfactants. Exchange rates of 14-s-14 (s = 2, 3, and 4) between the micelle form and monomer in solution were detected by two NMR methods: one-dimensional (1D) line shape analysis and two-dimensional (2D) exchange spectroscopy (EXSY). Results show that the nonionic surfactants (TX-100 and Brij-35), the cationic surfactant (TTAB), and the ionic surfactant (SDS) respectively accelerated, barely influenced, and slowed the exchange rate of 14-s-14. The effect mechanism was investigated by the self-diffusion experiment, relaxation time measurements (T(2)/T(1)), the fluorescence experiment (I(1)/I(3)) and observed chemical shift variations. Results reveal that, nonionic conventional surfactants (TX-100 and Brij-35) loosened the molecule arrangement and decreased hydrophobic interactions in the micelle, and thus accelerated the exchange rate of 14-s-14. The cationic conventional surfactant (TTAB) barely changed the molecule arrangement and thus barely influenced the exchange rate of 14-s-14. The ionic conventional surfactant (SDS) introduced the electrostatic attraction effect, tightened the molecule arrangement, and increased hydrophobic interactions in the micelle, and thus slowed down the exchange rate of 14-s-14. Additionally, the two-step exchange mechanism of 14-s-14 in the mixed solution was revealed through interesting variation tendencies of exchange rates of 14-s-14.

A novel nonionic surfactant- and solvent-stable alkaline serine protease from Serratia sp. SYBC H with duckweed as nitrogen source: production, purification, characteristics and application.

PubMed

Li, G Y; Cai, Y J; Liao, X R; Yin, J

2011-07-01

A novel nonionic surfactant- and hydrophilic solvent-stable alkaline serine protease was purified from the culture supernatant of Serratia sp. SYBC H with duckweed as nitrogen source. The molecular mass of the purified protease is about 59 kDa as assayed via SDS-PAGE. The protease is highly active over the pH range between 5.0 and 11.0, with the maximum activity at pH 8.0. It is also fairly active over the temperature range between 30 and 80°C, with the maximum activity at 40°C. The protease activity was substantially stimulated by Mn(2+) and Na(+) (5 mM), up to 837.9 and 134.5% at 40°C, respectively. In addition, Mn(2+) enhanced the thermostability of the protease significantly at 60°C. Over 90% of its initial activity remained even after incubating for 60 min at 40°C in 50% (v/v) hydrophilic organic solvents such as DMF, DMSO, acetone and MeOH. The protease retained 81.7, 83.6 and 76.2% of its initial activity in the presence of nonionic surfactants 20% (v/v) Tween 80, 25% (v/v) glycerol and Triton X-100, respectively. The protease is strongly inhibited by PMSF, suggesting that it is a serine protease. Washing experiments revealed that the protease has an excellent ability to remove blood stains.

Colorimetric detection of melamine in milk based on Triton X-100 modified gold nanoparticles and its paper-based application

NASA Astrophysics Data System (ADS)

Gao, Nan; Huang, Pengcheng; Wu, Fangying

2018-03-01

In this study, we have developed a method for rapid, highly efficient and selective detection of melamine. The negatively charged citrate ions form an electrostatic layer on gold nanoparticles (AuNPs) and keep the NPs dispersed and stable. When citrate-capped AuNPs were further modified with Triton X-100, it stabilized the AuNPs against the conditions of high ionic strength and a broad pH range. However, the addition of melamine caused the destabilization and aggregation of NPs. This may be attributed to the interaction between melamine and the AuNPs through the ligand exchange with citrate ions on the surface of AuNPs leading Triton X-100 to be removed. As a result, the AuNPs were unstable, resulting in the aggregation. The aggregation induced a wine red-to-blue color change, and a new absorption peak around 630 nm appeared. Triton X-100-AuNPs could selectively detect melamine at the concentration as low as 5.1 nM. This probe was successfully applied to detect melamine in milk. Furthermore, paper-based quantitative detection system using this colorimetric probe was also demonstrated by integrating with a smartphone.

Measurement of tritium in natural water

NASA Astrophysics Data System (ADS)

Li, Meifen

1985-06-01

A detergent-scintillation liquid mixture applied to measure low specific activity of tritium in natural water was studied. The DYS-1 low level liquid scintillation counter designed and manufactured by our institute was employed. In comparing the Triton X-100 scintillation liquid mixture with the dioxane-based-scintillation liquid, a better formula for Triton X-100 scintillation liquid mixture was determined, the mixture possesses the quality of high water content; high efficiency and low back-ground in measuring tritium in water. Chemiluminescence of the Triton X-100 scintillation liquid mixture can be totally de-excited in short time. It can be employed at ambient temperature 11 28°C. For 20ml sample in quartz vials, counting efficiency is 15% with a background 2.17 cpm, Y=31 TU (t=30 min).

Fundamental studies of glucose oxidase deposition on a Pt electrode.

PubMed

Matsumoto, Norio; Chen, Xiaohong; Wilson, George S

2002-01-15

The direct electrodeposition of glucose oxidase (EC 1.1.3.4) on a platinum electrode was investigated as a means for controlled immobilization. The presence of a nonionic detergent, Triton X-100, was found essential to produce a multilayered deposit. Moreover, to work properly, the detergent must be present above its critical micelle concentration. Under these conditions, a deposit of approximately 50 enzyme layers (480 nm), with surface uniformity of +/-20 nm, was verified using an electrochemical quartz crystal microbalance and by atomic force microscopy. In the absence of detergent, a layer of 25 nm is formed. Contrary to most previous claims, the deposition, which is potential dependent but optimal at 1.3 V versus AgCl/Ag electrode, is not electrophoretically driven, but is instead controlled by a lowering of the pH at the electrode surface due to concomitant oxygen evolution.

The effect of a non-denaturing detergent and a guanidinium-based inactivation agent on the viability of Ebola virus in mock clinical serum samples.

PubMed

Burton, J E; Easterbrook, L; Pitman, J; Anderson, D; Roddy, S; Bailey, D; Vipond, R; Bruce, C B; Roberts, A D

2017-12-01

The 2014 Ebola outbreak in West Africa required the rapid testing of clinical material for the presence of potentially high titre Ebola virus (EBOV). Safe, fast and effective methods for the inactivation of such clinical samples are required so that rapid diagnostic tests including downstream analysis by RT-qPCR or nucleotide sequencing can be carried out. One of the most commonly used guanidinium - based denaturing agents, AVL (Qiagen) has been shown to fully inactivate EBOV once ethanol is added, however this is not compatible with the use of automated nucleic acid extraction systems. Additional inactivation agents need to be identified that can be used in automated systems. A candidate inactivation agent is Triton X-100, a non-denaturing detergent that is frequently used in clinical nucleic acid extraction procedures and has previously been used for inactivation of EBOV. In this study the effect of 0.1% and 1.0% Triton X-100 (final concentration 0.08% and 0.8% respectively) alone and in combination with AVL on the viability of EBOV (10 6 TCID 50 /ml) spiked into commercially available pooled negative human serum was tested. The presence of viable EBOV in the treated samples was assessed by carrying out three serial passages of the samples in Vero E6 cells (37°C, 5% CO 2 , 1 week for each passage). At the end of each passage the cells were observed for evidence of cytopathic effect and samples were taken for rRT-PCR analysis for the presence of EBOV RNA. Before cell culture cytotoxic components of AVL and Triton X-100 were removed from the samples using size exclusion spin column technology or a hydrophobic adsorbent resin. The results of this study showed that EBOV spiked into human serum was not fully inactivated when treated with either 0.1% (v/v) Triton X-100 for 10 mins or 1.0% (v/v) Triton X-100 for 20 mins (final concentrations 0.08% and 0.8% Triton X-100 respectively). AVL alone also did not consistently provide complete inactivation. Samples treated with both AVL and 0.1% Triton X-100 for 10 or 20 mins were shown to be completely inactivated. This treatment is compatible with downstream analysis by RT-qPCR and next generation sequencing. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Optimization and critical evaluation of decellularization strategies to develop renal extracellular matrix scaffolds as biological templates for organ engineering and transplantation.

PubMed

Caralt, M; Uzarski, J S; Iacob, S; Obergfell, K P; Berg, N; Bijonowski, B M; Kiefer, K M; Ward, H H; Wandinger-Ness, A; Miller, W M; Zhang, Z J; Abecassis, M M; Wertheim, J A

2015-01-01

The ability to generate patient-specific cells through induced pluripotent stem cell (iPSC) technology has encouraged development of three-dimensional extracellular matrix (ECM) scaffolds as bioactive substrates for cell differentiation with the long-range goal of bioengineering organs for transplantation. Perfusion decellularization uses the vasculature to remove resident cells, leaving an intact ECM template wherein new cells grow; however, a rigorous evaluative framework assessing ECM structural and biochemical quality is lacking. To address this, we developed histologic scoring systems to quantify fundamental characteristics of decellularized rodent kidneys: ECM structure (tubules, vessels, glomeruli) and cell removal. We also assessed growth factor retention--indicating matrix biofunctionality. These scoring systems evaluated three strategies developed to decellularize kidneys (1% Triton X-100, 1% Triton X-100/0.1% sodium dodecyl sulfate (SDS) and 0.02% Trypsin-0.05% EGTA/1% Triton X-100). Triton and Triton/SDS preserved renal microarchitecture and retained matrix-bound basic fibroblast growth factor and vascular endothelial growth factor. Trypsin caused structural deterioration and growth factor loss. Triton/SDS-decellularized scaffolds maintained 3 h of leak-free blood flow in a rodent transplantation model and supported repopulation with human iPSC-derived endothelial cells and tubular epithelial cells ex vivo. Taken together, we identify an optimal Triton/SDS-based decellularization strategy that produces a biomatrix that may ultimately serve as a rodent model for kidney bioengineering. © Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.

Facile Modification of Reverse Osmosis Membranes by Surfactant-Assisted Acrylate Grafting for Enhanced Selectivity.

PubMed

Baransi-Karkaby, Katie; Bass, Maria; Levchenko, Stanislav; Eitan, Shahar; Freger, Viatcheslav

2017-02-21

The top polyamide layer of composite reverse osmosis (RO) membranes has a fascinatingly complex structure, yet nanoscale nonuniformities inherently present in polyamide layer may reduce selectivity, e.g., for boron rejection. This study examines improving selectivity by in situ "caulking" such nonuniformities using concentration polarization-enhanced graft-polymerization with a surfactant added to the reactive solution. The surfactant appears to enhance both polarization (via monomer solubilization in surfactant micelles) and adherence of graft-polymer to the membrane surface, which facilitates grafting and reduces monomer consumption. The effect of surfactant was particularly notable for a hydrophobic monomer glycidyl methacrylate combined with a nonionic surfactant Triton X-100. With Triton added at an optimal level, close to critical micellization concentration (CMC), monomer gets solubilized and highly concentrated within micelles, which results in a significantly increased degree of grafting and uniformity of the coating compared to a procedure with no surfactant added. Notably, no improvement was obtained for an anionic surfactant SDS or the cationic surfactant DTAB, in which cases the high CMC of surfactant precludes high monomer concentration within micelles. The modification procedure was also up-scalable to membranes elements and resulted in elements with permeability comparable to commercial brackish water RO elements with superior boric acid rejection.

Conjugates of ubiquitin cross-reactive protein distribute in a cytoskeletal pattern.

PubMed Central

Loeb, K R; Haas, A L

1994-01-01

Ubiquitin cross-reactive protein (UCRP), a 15-kDa interferon-induced protein, is a sequence homolog of ubiquitin that is covalently ligated to intracellular proteins in a parallel enzymatic reaction and is found at low levels within cultured cell lines and human tissues not exposed to interferon. Ubiquitin and UCRP ligation reactions apparently target distinct subsets of intracellular proteins, as judged from differences in the distributions of the respective adducts revealed on immunoblots. In this study, successive passages of the human lung carcinoma line A549 in the presence of neutralizing antibodies against alpha and beta interferons had no effect on the levels of either free or conjugated UCRP, indicating that these UCRP pools are constitutively present within uninduced cells and are thus not a consequence of autoinduction by low levels of secreted alpha/beta interferon. In an effort to identify potential targets for UCRP conjugation, the immunocytochemical distribution of UCRP was examined by using affinity-purified polyclonal antibodies against recombinant polypeptide. UCRP distributes in a punctate cytoskeletal pattern that is resistant to extraction by nonionic detergents (e.g., Triton X-100) in both uninduced and interferon-treated A549 cells. The cytoskeletal pattern colocalizes with the intermediate filament network of epithelial and mesothelial cell lines. Immunoblots of parallel Triton X-100-insoluble cell extracts suggest that the cytoskeletal association largely results from the noncovalent association of UCRP conjugates with the intermediate filaments rather than direct ligation of the polypeptide to structural components of the filaments. A significant increase in the sequestration of UCRP adducts on intermediate filaments accompanies interferon induction. These results suggest that UCRP may serve as a trans-acting binding factor directing the association of ligated target proteins to intermediate filaments. Images PMID:7526157

Differential effects of non-ionic detergents on microsomal and sarcolemmal adenylate cyclase in cardiac muscle

PubMed Central

Sulakhe, Prakash V.; Narayanan, Njanoor

1978-01-01

1. About 4 and 23% of the homogenate adenylate cyclase activity was recovered in the microsomal and sarcolemmal fractions isolated from guinea-pig heart ventricles. 2. Cardiac microsomal adenylate cyclase activity [basal as well as p[NH]ppG (guanyl-5′-yl imidodiphosphate)- and NaF-stimulated] was increased over 2-fold in the presence of Lubrol-PX (0.01–0.1%). 3. The sarcolemmal enzyme, however, showed concentration-dependent inhibition caused by the detergent under all assay conditions, except when p[NH]ppG was included in the assay. In the latter case, the detergent (0.01–0.02%) caused a modest increase (30–45%) in enzyme activity. 4. Another non-ionic detergent, Triton X-100, also stimulated the microsomal cyclase and inhibited the sarcolemmal enzyme. 5. With either membrane fraction, Lubrol-PX solubilized the enzyme when the detergent/membrane protein ratio was 2.5 (μmol of detergent/mg of protein). 6. The findings with homogenate and a washed particulate fraction resembled those obtained with sarcolemma, and those with isolated sarcoplasmic reticulum resembled those with microsomal preparations. 7. p[NH]ppG, and to some extent NaF, protected the detergent-induced inactivation of the enzyme observed at higher detergent concentrations (0.5% Lubrol-PX and 0.05–0.5% Triton X-100). 8. In the absence of detergents, p[NH]ppG increased the basal enzyme activity about 2-fold in microsomal fractions, but did not appreciably stimulate the sarcolemmal enzyme. Isoproterenol, on the other hand, increased the sarcolemmal enzyme activity (>2-fold) in the presence of p[NH]ppG and caused only moderate stimulation (31%) of the microsomal enzyme under these conditions. 9. These findings support the view that, although the bulk of adenylate cyclase resides in heart sarcolemma (plasma membrane), the microsomal activity cannot be accounted for solely by contamination of the microsomal fraction with sarcolemma, as has been suggested by others [Besch, Jones & Watanabe (1976) Circ. Res. 39, 586–595; Engelhard, Plut & Storm (1976) Biochim. Biophys. Acta 451, 48–61]. Further, the results of this study show that cardiac sarcoplasmic-reticulum membranes possess this enzyme. PMID:736892

Reversible Lifting of Surface Supported Lipid Bilayers with a Membrane-Spanning Nonionic Triblock Copolymer

DOE PAGES

Hayden, Steven C.; Junghans, Ann; Majewski, Jaroslaw; ...

2017-02-22

Neutron reflectometry was used to monitor structural variations in surface supported DMPC bilayers induced by the addition of Triton X-100, a surfactant commonly used to aid solubilization of membrane proteins, and the co-addition of a membrane spanning non-ionic amphiphilic triblock copolymer, (PEO 117-PPO 47-PE O117, Pluronic F98). Surfactant addition causes slight compression of the bilayer thickness and the creation of a distinct EO layer that increases the hydrophilic layer proximal to the supporting substrate (i.e., a water and EO gap between the lipid bilayer and quartz) to 6.8 ± 0.4 Å. Addition of the triblock copolymer into the DMPC: Tritonmore » X-100 bilayer increases the complexity (broadens) the lipid phase transition, further compresses the bilayer, and continues to expand the proximal hydrophilic layer thickness. The observed structural changes are temperature dependent with transmembrane polymer insertion achieved at 37 °C leading to a compressed membrane thickness of 39.2 ± 0.2 Å and proximal gap of 45.2 ± 0.2 Å. Temperature driven exclusion of the polymer at 15 °C causes partitioning of the polymer into the proximal space generating a large hydrogel cushion 162 ± 16 Å thick. An intermediate gap width (10 – 27 Å) is achieved at room temperature (22 – 25 °C). The temperature-driven changes in the proximal hydrophilic gap dimensions are shown to be reversible but thermal history causes variation in magnitude. Temperature-driven changes in polymer association with a supported lipid bilayer offer a facile means to reversibly control both the membrane characteristics as well as the separation between membrane and solid substrate.« less

Reversible Lifting of Surface Supported Lipid Bilayers with a Membrane-Spanning Nonionic Triblock Copolymer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayden, Steven C.; Junghans, Ann; Majewski, Jaroslaw

Neutron reflectometry was used to monitor structural variations in surface supported DMPC bilayers induced by the addition of Triton X-100, a surfactant commonly used to aid solubilization of membrane proteins, and the co-addition of a membrane spanning non-ionic amphiphilic triblock copolymer, (PEO 117-PPO 47-PE O117, Pluronic F98). Surfactant addition causes slight compression of the bilayer thickness and the creation of a distinct EO layer that increases the hydrophilic layer proximal to the supporting substrate (i.e., a water and EO gap between the lipid bilayer and quartz) to 6.8 ± 0.4 Å. Addition of the triblock copolymer into the DMPC: Tritonmore » X-100 bilayer increases the complexity (broadens) the lipid phase transition, further compresses the bilayer, and continues to expand the proximal hydrophilic layer thickness. The observed structural changes are temperature dependent with transmembrane polymer insertion achieved at 37 °C leading to a compressed membrane thickness of 39.2 ± 0.2 Å and proximal gap of 45.2 ± 0.2 Å. Temperature driven exclusion of the polymer at 15 °C causes partitioning of the polymer into the proximal space generating a large hydrogel cushion 162 ± 16 Å thick. An intermediate gap width (10 – 27 Å) is achieved at room temperature (22 – 25 °C). The temperature-driven changes in the proximal hydrophilic gap dimensions are shown to be reversible but thermal history causes variation in magnitude. Temperature-driven changes in polymer association with a supported lipid bilayer offer a facile means to reversibly control both the membrane characteristics as well as the separation between membrane and solid substrate.« less

Cloud point extraction: an alternative to traditional liquid-liquid extraction for lanthanides(III) separation.

PubMed

Favre-Réguillon, Alain; Draye, Micheline; Lebuzit, Gérard; Thomas, Sylvie; Foos, Jacques; Cote, Gérard; Guy, Alain

2004-06-17

Cloud point extraction (CPE) was used to extract and separate lanthanum(III) and gadolinium(III) nitrate from an aqueous solution. The methodology used is based on the formation of lanthanide(III)-8-hydroxyquinoline (8-HQ) complexes soluble in a micellar phase of non-ionic surfactant. The lanthanide(III) complexes are then extracted into the surfactant-rich phase at a temperature above the cloud point temperature (CPT). The structure of the non-ionic surfactant, and the chelating agent-metal molar ratio are identified as factors determining the extraction efficiency and selectivity. In an aqueous solution containing equimolar concentrations of La(III) and Gd(III), extraction efficiency for Gd(III) can reach 96% with a Gd(III)/La(III) selectivity higher than 30 using Triton X-114. Under those conditions, a Gd(III) decontamination factor of 50 is obtained.

Isolation and immunochemical characterization of fractions from membranes of Aspergillus fumigatus with protease activity.

PubMed

Piechura, J E; Kurup, V P; Daft, L J

1990-01-01

Two fractions exhibiting acid protease activity (AFPI and AFPII) were isolated by extraction of membrane vesicles of Aspergillus fumigatus with Triton X-100. These two fractions produced single bands in both polyacrylamide and sodium dodecyl sulfate polyacrylamide gel electrophoresis and showed apparent molecular weights of 73,000 and 43,000, respectively. Molecular weights determined by gel filtration in the absence and presence of Triton X-100 and sedimentation velocities in analytical ultracentrifugation indicated hydrophobic characteristics, since both fractions readily aggregated and complexed with Triton X-100; both exhibited elevated enzyme activities in the presence of Triton X-100. Carbohydrate content was 93% for AFPI and 85% for AFPII. The enzymatic fractions demonstrated different pH optima in the acid range as well as different temperature stabilities. Both protease fractions cross reacted in double immunodiffusion, while in crossed immunoelectrophoresis both demonstrated five precipitin peaks, each with similar patterns. AFPI demonstrated two additional precipitin peaks in crossed immunoelectrophoresis. As determined by crossed immunoaffinoelectrophoresis, the protease fractions demonstrated galactose and mannose residues. In biotin-avidin enzyme-linked immunosorbent assay both fractions reacted with allergic bronchopulmonary aspergillosis and aspergilloma sera. It can be concluded that two fractions with protease activity of A. fumigatus reported here may be of significance in Aspergillus-induced diseases.

Effect of mesoporous g-C3N4 substrate on catalytic oxidation of CO over Co3O4

NASA Astrophysics Data System (ADS)

Yang, Heng; Lv, Kangle; Zhu, Junjiang; Li, Qin; Tang, Dingguo; Ho, Wingkei; Li, Mei; Carabineiro, Sónia A. C.

2017-04-01

Mesoporous graphitic carbon nitride (mpg-CN) was synthesized using Triton X-100, a surfactant containing a hydrophilic polyethylene oxide group and a tert-octyl-phenyl hydrophobic moiety, as a soft template. The obtained mpg-CN was used as a support for Co3O4, and this supported catalyst was used for CO oxidation. The effects of the amount of Triton X-100, weight ratio of Co3O4 to mpg-CN and calcination temperature on the catalytic performances for CO oxidation of Co3O4/mpg-CN composites were systematically studied. It was found that the presence of Triton X-100 not only retarded the polymerization of dicyandiamide, but also affected the microstructure of Co3O4. Bubbles formed because of the hydrophobic group of the surfactant Triton X-100 can be act as a soft template for the synthesis of mesoporous g-C3N4. The enhanced catalytic activity of Co3O4/mpg-CN was attributed to a synergistic effect, enlarged BET surface areas, increased Co3+ and lattice oxygen contents, and the porous structure of mpg-CN support. The high stability of 12.5% Co3O4/mpg-CN(1.0) makes it a promising catalyst for practical applications.

Analysis of three variables in sampling solutions used to assay bacteria of hands: type of solution, use of antiseptic neutralizers, and solution temperature.

PubMed Central

Larson, E L; Strom, M S; Evans, C A

1980-01-01

Tests were performed using the sterile bag technique to determine the effects of type of sampling solution, use of antiseptic neutralizers, and solution temperature on the detection and quantitation of bacteria on hands. Using paired hand cultures, three sampling solutions were compared: quarter-strength Ringer solution, a phosphate buffer containing Triton X-100, and the same buffer containing antiseptic neutralizers. The phosphate buffer containing Triton X-100 was significantly better than quarter-strength Ringer solution in mean bacterial yield; the neutralizer-containing sampling solution was slightly better than Triton X-100-containing solution, although differences were not significant at the P = 0.05 level. Temperature (6 or 23 degrees C) of the sampling solution showed no consistent effect on bacterial yield from hands tested with the fluid containing neutralizers. PMID:7012171

Evaluation of eco-friendly zwitterionic detergents for enveloped virus inactivation.

PubMed

Conley, Lynn; Tao, Yinying; Henry, Alexis; Koepf, Edward; Cecchini, Douglas; Pieracci, John; Ghose, Sanchayita

2017-04-01

Inclusion of a detergent in protein biotherapeutic purification processes is a simple and very robust method for inactivating enveloped viruses. The detergent Triton X-100 has been used for many years and is part of the production process of several commercial therapeutic proteins. However, recent ecological studies have suggested that Triton X-100 and its break-down products can potentially behave as endocrine disrupters in aquatic organisms, raising concerns from an environmental impact perspective. As such, discharge of Triton X-100 into the waste water treatment plants is regulated in some jurisdictions, and alternative detergents for viral inactivation are required. In this work, we report on the identification and evaluation of more eco-friendly detergents as viable replacements for Triton X-100. Five detergent candidates with low to moderate environmental impact were initially identified and evaluated with respect to protein stability, followed by proof-of-concept virus inactivation studies using a model enveloped virus. From the set of candidates lauryldimethylamine N-oxide (LDAO) was identified as the most promising detergent due to its low ecotoxicity, robust anti-viral activity (LRV >4 at validation set-point conditions with X-MuLX), and absence of any negative impact on protein function. This detergent exhibited effective and robust virus inactivation in a broad range of protein concentrations, solution conductivities, pHs, and in several different cell culture fluid matrices. The only process parameter which correlated with reduced virus inactivation potency was LDAO concentration, and then only when the concentration was reduced to below the detergent's critical micelle concentration (CMC). Additionally, this work also demonstrated that LDAO was cleared to below detectable levels after Protein A affinity chromatography, making it suitable for use in a platform process that utilizes this chromatographic mode for protein capture. All these findings suggest that LDAO may be a practical alternative to Triton X-100 for use in protein therapeutic production processes for inactivating enveloped viruses. Biotechnol. Bioeng. 2017;114: 813-820. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The Role of Acoustic Cavitation in Ultrasound-triggered Drug Release from Echogenic Liposomes

NASA Astrophysics Data System (ADS)

Kopechek, Jonathan A.

Cardiovascular disease (CVD) is the leading cause of death in the United States and globally. CVD-related mortality, including coronary heart disease, heart failure, or stroke, generally occurs due to atherosclerosis, a condition in which plaques build up within arterial walls, potentially causing blockage or rupture. Targeted therapies are needed to achieve more effective treatments. Echogenic liposomes (ELIP), which consist of a lipid membrane surrounding an aqueous core, have been developed to encapsulate a therapeutic agent and/or gas bubbles for targeted delivery and ultrasound image enhancement. Under certain conditions ultrasound can cause nonlinear bubble growth and collapse, known as "cavitation." Cavitation activity has been associated with enhanced drug delivery across cellular membranes. However, the mechanisms of ultrasound-mediated drug release from ELIP have not been previously investigated. Thus, the objective of this dissertation is to elucidate the role of acoustic cavitation in ultrasound-mediated drug release from ELIP. To determine the acoustic and physical properties of ELIP, the frequency-dependent attenuation and backscatter coefficients were measured between 3 and 30 MHz. The results were compared to a theoretical model by measuring the ELIP size distribution in order to determine properties of the lipid membrane. It was found that ELIP have a broad size distribution and can provide enhanced ultrasound image contrast across a broad range of clinically-relevant frequencies. Calcein, a hydrophilic fluorescent dye, and papaverine, a lipophilic vasodilator, were separately encapsulated in ELIP and exposed to color Doppler ultrasound pulses from a clinical diagnostic ultrasound scanner in a flow system. Spectrophotometric techniques (fluorescence and absorbance measurements) were used to detect calcein or papaverine release. As a positive control, Triton X-100 (a non-ionic detergent) was added to ELIP samples not exposed to ultrasound in order to release encapsulated agents completely. Also, sham samples without Triton X-100 or ultrasound exposure were used as negative controls. Color Doppler ultrasound did not release encapsulated calcein or papaverine from ELIP even though there was a complete loss of echogenicity. In subsequent experiments, calcein and rosiglitazone, a hydrophobic anti-diabetic drug, were separately encapsulated in ELIP and exposed to pulsed Doppler ultrasound in a flow system while monitoring cavitation. Samples were exposed to ultrasound pressures above and below cavitation thresholds. In addition, Triton X-100 was used for positive control samples and sham samples were also tested without ultrasound exposure. Adding Triton X-100 resulted in complete release of encapsulated calcein or rosiglitzone. However, Doppler ultrasound exposure did not induce calcein or rosiglitazone release from ELIP in the flow system even when there was persistent cavitation activity and a loss of echogenicity. The results of this dissertation indicate that cavitation of encapsulated bubbles in ELIP solutions is not sufficient to induce drug release. It is possible that ultrasoundmediated thermal processes may have a stronger effect on ELIP permeability than cavitation activity. Perhaps ultrasound-triggered drug release will be possible by improving the ELIP formulation or encapsulating a different gas instead of air. However, cavitation is not a reliable indicator of ultrasound-mediated drug release with the ELIP formulations used in this dissertation.

Effects of rhamnolipid on the cellulase and xylanase in hydrolysis of wheat straw.

PubMed

Wang, Hong-Yuan; Fan, Bing-Quan; Li, Chun-Hua; Liu, Shuang; Li, Min

2011-06-01

The effects of biosurfactant rhamnolipid (RL) and chemical surfactant Triton X-100 on the production of cellulases and xylanase from Penicillium expansum (P. expansum) in untreated, acid- and alkali-pretreated wheat straw submerged fermentations were studied, and the influences on the activity and stability of Cellulase R-10 were also investigated. The results showed that RL and Triton X-100 enhanced the activities of cellulases and xylanase to different extents and the stimulatory effects of RL were superior to those of Triton X-100. During the peak enzyme production phase, RL (60 RE mg/l) increased cellulases activities by 25.5-102.9%, in which the raise of the same enzyme in acid-pretreated straw broths was the most. It was found that the reducing sugars by hydrolyzing wheat straw with Cellulase R-100 were not visibly increased after adding RL. However, it distinctly protected Cellulase R-10 from degradation or inactivation, keeping the reducing sugars yield at about 17%. Copyright © 2011. Published by Elsevier Ltd.

[Membrane lipids and electron transfer. Effects of four detergents on NADH-ferricyanide reductase and NADH-cytochrome c reductase activities of potato tuber microsomes].

PubMed

Jolliot, A; Mazliak, P

1977-10-17

The NADH-ferricyanure reductase activity of Potato microsomes is stimulated by non ionic detergents (Triton X100 and Tween80) and is partially inhibited by ionic detergents (sodium-cholate and deoxycholate). All these four detergents progressively decreased the NADH-cytochrome c reductase in the following order: sodium deoxycholate greater than Triton X100 greater than sodium cholate greater than Tween80.

Aggregate-based sub-CMC Solubilization of Hexadecane by Surfactants.

PubMed

Zhong, Hua; Yang, Lei; Zeng, Guangming; Brusseau, Mark L; Wang, Yake; Li, Yang; Liu, Zhifeng; Yuan, Xingzhong; Tan, Fei

Solubilization of hexadecane by two surfactants, SDBS and Triton X-100, at concentrations near the critical micelle concentration (CMC) and the related aggregation behavior was investigated in this study. Solubilization was observed at surfactant concentrations lower than CMC, and the apparent solubility of hexadecane increased linearly with surfactant concentration for both surfactants. The capacity of SDBS to solubilize hexadecane is stronger at concentrations below CMC than above CMC. In contrast, Triton X-100 shows no difference. The results of dynamic light scattering (DLS) and cryogenic TEM analysis show aggregate formation at surfactant concentrations lower than CMC. DLS-based size of the aggregates ( d ) decreases with increasing surfactant concentration. Zeta potential of the SDBS aggregates decreases with increasing SDBS concentration, whereas it increases for Triton X-100. The surface excess (Γ) of SDBS calculated based on hexadecane solubility and aggregate size data increases rapidly with increasing bulk concentration, and then asymptotically approaches the maximum surface excess (Γ max ). Conversely, there is only a minor increase in Γ for Triton X-100. Comparison of Γ and d indicates that excess of surfactant molecules at aggregate surface has great impact on surface curvature. The results of this study demonstrate formation of aggregates at surfactant concentrations below CMC for hexadecane solubilization, and indicate the potential of employing low-concentration strategy for surfactant application such as remediation of HOC contaminated sites.

Surfactant-enhanced remediation of a trichloroethene-contaminated aquifer. 2. Transport of TCE

USGS Publications Warehouse

Sahoo, D.; Smith, J.A.; Imbrigiotta, T.E.; Mclellan, H.M.

1998-01-01

Field studies were conducted under an induced gradient in a trichloroethene (TCE)-contaminated aquifer at Picatinny Arsenal, NJ, to study (a) the rate-limited desorption of TCE from aquifer sediments to water and (b) the effect of a surfactant (Triton X-100) on the desorption and transport of TCE. Clean water was injected into the contaminated aquifer for 206 day. Triton X-100 was added for a 36-day period (days 36-71 from the start of clean water injection). The effect of Triton X-100 on the desorption and transport of TCE in the field was examined by observing the concentrations of these two solutes in four monitoring wells 3-9 m from the injection wells. These data show a small but discernible increase in the TCE concentration in two of the wells corresponding approximately to the time when surfactant reaches the wells; in the other two monitoring wells, the increase in TCE concentration is negligible. A solute transport model that assumes local sorption equilibrium and used a laboratory-derived distribution coefficient could not adequately describe TCE desorption and transport observed in the aquifer. Two model formulations that accounted for rate-limited sorption - two-site and multisite models - fit the data well. TCE concentrations after surfactant injection were underpredicted by the models unless mass transfer rate was increased to account for the effect of surfactant on the rate of TCE desorption. The concentration data from the two wells and the model analysis suggest that the rate of TCE desorption is increased (by approximately 30%) as a result of Triton X-100 injection.Field studies were conducted under an induced gradient in a trichloroethene (TCE)-contaminated aquifer at Picatinny Arsenal, NJ, to study (a) the rate-limited desorption of TCE from aquifer sediments to water and (b) the effect of a surfactant (Triton X-100) on the desorption and transport of TCE. Clean water was injected into the contaminated aquifer for 206 day. Triton X-100 was added for a 36-day period (days 36-71 from the start of clean water injection). The effect of Triton X-100 on the desorption and transport of TCE in the field was examined by observing the concentrations of these two solutes in four monitoring wells 3-9 m from the injection wells. These data show a small but discernible increase in the TCE concentration in two of the wells corresponding approximately to the time when surfactant reaches the wells; in the other two monitoring wells, the increase in TCE concentration is negligible. A solute transport model that assumes local sorption equilibrium and used a laboratory-derived distribution coefficient could not adequately describe TCE desorption and transport observed in the aquifer. Two model formulations that accounted for rate-limited sorption - two-site and multisite models - fit the data well. TCE concentrations after surfactant injection were underpredicted by the models unless mass transfer rate was increased to account for the effect of surfactant on the rate of TCE desorption. The concentration data from the two wells and the model analysis suggest that the rate of TCE desorption is increased (by approximately 30%) as a result of Triton X-100 injection.

Influence of iron solubility and charged surface-active compounds on lipid oxidation in fatty acid ethyl esters containing association colloids.

PubMed

Homma, Rika; Johnson, David R; McClements, D Julian; Decker, Eric A

2016-05-15

The impact of iron compounds with different solubilities on lipid oxidation was studied in the presence and absence of association colloids. Iron (III) sulfate only accelerated lipid oxidation in the presence of association colloids while iron (III) oleate accelerated oxidation in the presence and absence of association colloids. Further, iron (III) oxide retarded lipid oxidation both with and without association colloids. The impact of charged association colloids on lipid oxidation in ethyl oleate was also investigated. Association colloids consisting of the anionic surface-active compound dodecyl sulphosuccinate sodium salt (AOT), cationic surface-active compound hexadecyltrimethylammonium bromide (CTAB), and nonionic surface-active compound 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol (Triton X-100) retarded, promoted, and had no effect on lipid oxidation rates, respectively. These results indicate that the polarity of metal compounds and the charge of association colloids play a big role in lipid oxidation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phosphoinositide-specific phospholipase C in oat roots: association with the actin cytoskeleton.

PubMed

Huang, Chiung-Hua; Crain, Richard C

2009-10-01

Phosphoinositide-specific phospholipase C (PI-PLC) activities are involved in mediating plant cell responses to environmental stimuli. Two variants of PI-PLC have been partially purified from the roots of oat seedlings; one cytosolic and one particulate. Although the cytosolic enzyme was significantly purified, the activity still co-migrated with a number of other proteins on heparin HPLC and also on size-exclusion chromatography. The partially purified PI-PLC was tested by Western blotting, and we found that actin and actin-binding proteins, profilin and tropomyosin, co-purified with cytosolic phospholipase C. After a non-ionic detergent (Triton X-100) treatment, PI-PLC activities still remained with the actin cytoskeleton. The effects of phalloidin and F-buffer confirmed this association; these conditions, which favor actin polymerization, decreased the release of PI-PLC from the cytoskeleton. The treatments of latrunculin and G-buffer, the conditions that favor actin depolymerization, increased the release of PI-PLC from the cytoskeleton. These results suggest that oat PI-PLC associates with the actin cytoskeleton.

Latent nitrate reductase activity is associated with the plasma membrane of corn roots

NASA Technical Reports Server (NTRS)

Ward, M. R.; Grimes, H. D.; Huffaker, R. C.

1989-01-01

Latent nitrate reductase activity (NRA) was detected in corn (Zea mays L., Golden Jubilee) root microsome fractions. Microsome-associated NRA was stimulated up to 20-fold by Triton X-100 (octylphenoxy polyethoxyethanol) whereas soluble NRA was only increased up to 1.2-fold. Microsome-associated NRA represented up to 19% of the total root NRA. Analysis of microsomal fractions by aqueous two-phase partitioning showed that the membrane-associated NRA was localized in the second upper phase (U2). Analysis with marker enzymes indicated that the U2 fraction was plasma membrane (PM). The PM-associated NRA was not removed by washing vesicles with up to 1.0 M NACl but was solubilized from the PM with 0.05% Triton X-100. In contrast, vanadate-sensitive ATPase activity was not solubilized from the PM by treatment with 0.1% Triton X-100. The results show that a protein capable of reducing nitrate is embedded in the hydrophobic region of the PM of corn roots.

Role of surfactant on thermoelectric behaviors of organic-inorganic composites

NASA Astrophysics Data System (ADS)

Shin, Sunmi; Roh, Jong Wook; Kim, Hyun-Sik; Chen, Renkun

2018-05-01

Hybrid organic/inorganic composites have recently attracted intensive interests as a promising candidate for flexible thermoelectric (TE) devices using inherently soft polymers as well as for increasing the degree of freedom to control TE properties. Experimentally, however, enhanced TE performance in hybrid composites has not been commonly observed, primarily due to inhomogeneous mixing between the inorganic and organic components which leads to limited electrical conduction in the less conductive component and consequently a low power factor in the composites compared to their single-component counterparts. In this study, we investigated the effects of different surfactants on the uniformity of mixing and the TE behaviors of the hybrid composites consisting of Bi0.5Sb1.5Te3 (BST) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). We found that compared to dimethyl sulfoxide, which is the most widely used surfactant, Triton X-100 (TX-100) can lead to homogenous dispersion of BST in PEDOT:PSS. By systematically studying the effects of the surfactant concentration, we can attribute the better mixing capability of TX-100 to its non-ionic property, which results in homogenous mixing with a lower critical micelle concentration. Consequently, we observed simultaneous increase in electrical conductivity and Seebeck coefficient in the BST/PEDOT:PSS composites with the TX-100 surfactant.

Desorption and mobility mechanisms of co-existing polycyclic aromatic hydrocarbons and heavy metals in clays and clay minerals.

PubMed

Saeedi, Mohsen; Li, Loretta Y; Grace, John R

2018-05-15

The effects of soil components such as clay minerals and as humic acids, as well as co-existing metals and polycyclic aromatic hydrocarbons, on desorption and mobility are examined. Three types of artificially blended clay and clay mineral mixtures (pure kaolinite, kaolinite + sand and kaolinite + sand + bentonite), each with different humic acid content, were tested for desorption and mobility of acenaphthene, fluorene and fluoranthene by three extracting solutions CaCl 2 (0.01 M) and EDTA (0.01M) with non-ionic surfactants (Tween 80 and Triton X100). Heavy metals (Ni, Pb and Zn) were also studied for desorption and mobility. The influence of co-present metals on simultaneous desorption and mobility of PAHs was investigated as well. The results showed that <10% of metals in the clay mineral mixtures were mobile. Combined EDTA and non-ionic solutions can enhance the desorption and mobility of PAHs to >80% in clay mineral mixtures containing no sand, while in the same soils containing ∼40% sand, the desorption exceeded 90%. Heavy metals, as well as increasing humic acids content in the clay mineral mixtures, decreased the desorption and mobility of PAHs, especially for soils containing no sand, and for fluoranthene compared with fluorene and acenaphthene. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhanced efficiency and air-stability of NiOX-based perovskite solar cells via PCBM electron transport layer modification with Triton X-100.

PubMed

Lee, Kisu; Ryu, Jaehoon; Yu, Haejun; Yun, Juyoung; Lee, Jungsup; Jang, Jyongsik

2017-11-02

We modified phenyl-C61-butyric acid methyl ester (PCBM) for use as a stable, efficient electron transport layer (ETL) in inverted perovskite solar cells (PSCs). PCBM containing a surfactant Triton X-100 acts as the ETL and NiO X nanocrystals act as a hole transport layer (HTL). Atomic force microscopy and scanning electron microscopy images showed that surfactant-modified PCBM (s-PCBM) forms a high-quality, uniform, and dense ETL on the rough perovskite layer. This layer effectively blocks holes and reduces interfacial recombination. Steady-state photoluminescence and electrochemical impedance spectroscopy analyses confirmed that Triton X-100 improved the electron extraction performance of PCBM. When the s-PCBM ETL was used, the average power conversion efficiency increased from 10.76% to 15.68%. This improvement was primarily caused by the increases in the open-circuit voltage and fill factor. s-PCBM-based PSCs also showed good air-stability, retaining 83.8% of their initial performance after 800 h under ambient conditions.

Effect of Surfactants on Mechanical, Thermal, and Photostability of a Monoclonal Antibody.

PubMed

Agarkhed, Meera; O'Dell, Courtney; Hsieh, Ming-Ching; Zhang, Jingming; Goldstein, Joel; Srivastava, Arvind

2018-01-01

The purpose of this work was to evaluate the effect of commonly used surfactants (at 0.01% w/v concentration) on mechanical, thermal, and photostability of a monoclonal antibody (MAb1) of IgG1 sub-class and to evaluate the minimum concentration of surfactant (Polysorbate 80) required in protecting MAb1 from mechanical stress. Surfactants evaluated were non-ionic surfactants, Polysorbate 80, Polysorbate 20, Pluronic F-68 (polyoxyethylene-polyoxypropylene block polymer), Brij 35 (polyoxyethylene lauryl ether), Triton X-100, and an anionic surfactant, Caprylic acid (1-Heptanecarboxylic acid). After evaluating effect of surfactants and determining stabilizing effect of Polysorbate 80 against mechanical stress without compromising thermal and photostability of MAb1, the minimum concentration of Polysorbate 80 required for mechanical stability was further examined. Polysorbate 80 concentration was varied from 0 to 0.02%. Mechanical stability was evaluated by agitation of MAb1 at 300 rotations per minute at room temperature for 72 h. Samples were analyzed for purity by SEC-HPLC, turbidity by absorbance at 350 nm, visible particles by visual inspection, and sub-visible particles by light obscuration technique on a particle analyzer. All non-ionic surfactants tested showed a similar effect in protecting against mechanical stress and did not exhibit any significant negative effect on thermal and photostability. However, Caprylic acid had a slightly negative effect on mechanical and photostability when compared to the non-ionic surfactants or sample without surfactant. This work demonstrated that polysorbate 80 is better than other surfactants tested and that a concentration of at least 0.005% (w/v) Polysorbate 80 is needed to protect MAb1 against mechanical stress.

Effect of inhibitors on Zn-dendrite formation for zinc-polyaniline secondary battery

NASA Astrophysics Data System (ADS)

Kan, Jinqing; Xue, Huaiguo; Mu, Shaolin

The effects of Pb 2+, sodium lauryl sulfate and Triton X-100 on inhibition of Zn-dendrite growth in Zn-polyaniline batteries were studied by scanning electron micrograph and cyclic voltammetry. The results show that Triton X-100 in the region of 0.02-500 ppm in the electrolyte containing 2.5 M ZnCl 2 and 2.0 M NH 4Cl with pH 4.40 can effectively inhibit zinc-dendrite growth during charge-discharge cycles of the battery and yield longer cycles.

[Effective reconstitution of sarcoplasmic reticulum Ca2+-ATPase using lubrol PX].

PubMed

Vinokurov, M G; Pechatnikov, V A

1991-01-01

Ca2(+)-ATPase of sarcoplasmic reticulum was reconstituted in the proteoliposomes by the salting out procedure. Triton X-100, C12E8 and Lubrol PX were used for the solubilization of the Ca2(+)-ATPase. Using fluorescent probes (diS-C3-(5), chlortetracycline) as well pH-measuring method, the functional of the reconstituted Ca2(+)-ATPase was comparatively studied in three types of proteoliposomes. The efficiency of Ca2(+)-ATPase grew in the following detergent order: Triton X-100, C12E8, Lubrol PX.

[Effect of natural or synthetic detergents on the transport of D-glucose in the membranes of vesicles of the brush border of the intestine of the rabbit].

PubMed

Favilli, F; Iantomasi, T; Stio, M; Treves, C; Vanni, P; Vincenzini, M T

1988-01-01

We describe here the effects of natural and synthetic detergents on the D-glucose transport into brush-border membranes of vesicles of rabbit's intestine. Two synthetic detergents: Triton X-100 and dodecyltrimethylammonium bromide have been found very strong inhibitors (more than 50 p. 100 of inhibition of maximal D-glucose uptake). Kinetic studies showed that these detergents behaved as mixed type inhibitors. The Na+-dependent transport of amino acids (aspartic acid, lysine, phenylalanine) is only poorly affected by dodecyltrimethylammonium bromide, while Triton X-100 inhibits unspecifically all the transport studied.

Tracking of pigment accumulation and secretion in extractive fermentation of Monascus anka GIM 3.592.

PubMed

Chen, Gong; Bei, Qi; Huang, Tao; Wu, Zhenqiang

2017-10-04

Monascus pigments are promising sources for food and medicine due to their natural food-coloring functions and pharmaceutical values. The innovative technology of extractive fermentation is used to promote pigment productivity, but reports of pigment trans-membrane secretion mechanism are rare. In this study, tracking of pigment accumulation and secretion in extractive fermentation of Monascus anka GIM 3.592 was investigated. The increased vacuole size in mycelia correlated with fluorescence intensity (r > 0.85, p < 0.05), which indicates that intracellular pigments with strong fluorescence accumulated in the cytoplasmic vacuole. After adding nonionic surfactant Triton X-100, the uptake of rhodamine123 (Rh123) and 1-N-phenylnaphthylamine (NPN) and the release of K + and Na + rapidly increased, demonstrating that the physiological performances of the cell membrane varied upon damaging the integrity, increasing the permeability, and changing the potential. Simultaneously, the fatty acid composition also varied, which caused a weak fluidity in the membrane lipids. Therefore, the intracellular pigments embedded in Triton X-100 were secreted through the ion channels of the cell membrane. Dense, spherical pigment-surfactant micelles with an average size of 21 nm were distributed uniformly in the extraction broth. Based on the different pigment components between extractive fermentation and batch fermentation, a threefold decrease in the NAD + /NADH ratio in mycelia and a more than 200-fold increase in glucose-6-phosphate dehydrogenase (G6PDH) activity in extracellular broth occurred, further suggesting that a reduction reaction for pigment conversion from orange pigments to yellow pigments occurred in non-aqueous phase solution. A putative model was established to track the localization of Monascus pigment accumulation and its trans-membrane secretion in extractive fermentation. This finding provides a theoretical explanation for microbial extractive fermentation of Monascus pigments, as well as other non-water-soluble products.

Cloud point extraction and diffuse reflectance-Fourier transform infrared spectroscopic determination of chromium(VI): A probe to adulteration in food stuffs.

PubMed

Tiwari, Swapnil; Deb, Manas Kanti; Sen, Bhupendra K

2017-04-15

A new cloud point extraction (CPE) method for the determination of hexavalent chromium i.e. Cr(VI) in food samples is established with subsequent diffuse reflectance-Fourier transform infrared (DRS-FTIR) analysis. The method demonstrates enrichment of Cr(VI) after its complexation with 1,5-diphenylcarbazide. The reddish-violet complex formed showed λ max at 540nm. Micellar phase separation at cloud point temperature of non-ionic surfactant, Triton X-100 occurred and complex was entrapped in surfactant and analyzed using DRS-FTIR. Under optimized conditions, the limit of detection (LOD) and quantification (LOQ) were 1.22 and 4.02μgmL -1 , respectively. Excellent linearity with correlation coefficient value of 0.94 was found for the concentration range of 1-100μgmL -1 . At 10μgmL -1 the standard deviation for 7 replicate measurements was found to be 0.11μgmL -1 . The method was successfully applied to commercially marketed food stuffs, and good recoveries (81-112%) were obtained by spiking the real samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of trace glucose and forecast of human diseases by affinity adsorption solid substrate room temperature phosphorimetry based on Triticum valgaris lectin labeled with 4.0-generation dendrimers

NASA Astrophysics Data System (ADS)

Li, Zhiming; Zhu, Guohui; Liu, Jiaming; Lu, Qiaomei; Yang, Minlan; Wu, Hong; Shi, Xiumei; Chen, Xinhua

2007-08-01

A new phosphorescence labeling reagent Triton-100X-4.0G-D (4.0G-D refers to 4.0-generation dendrimers) was found. Quantitative specific affinity adsorption (AA) reaction between Triton-100X-4.0G-D-WGA and glucose (G) was carried out on the surface of nitrocellulose membrane (NCM), and the Δ Ip of the product of AA reaction was linear correlation to the content of G. Based on the facts above, a new method for the determination of trace G was established by WGA labeled with Triton-100X-4.0G-D affinity adsorption solid substrate room temperature phosphorimetry (Triton-100X-4.0G-D-WGA-AA-SS-RTP). This research showed that AA-SS-RTP for either direct method or sandwich method could combine very well the characteristics of both the high sensitivity of SS-RTP and the specificity of the AA reaction. Detection limits (LD) were 0.24 fg spot -1 for direct method and 0.18 fg spot -1 for sandwich method, indicating both of them were of high sensitivity. The method has been applied to the determination of the content of G in human serum, and the results were coincided with those obtained by glucose oxidize enzyme method. It can also be applied to forecast accurately some human diseases, such as primary hepatic carcinoma, cirrhosis, acute and chronic hepatitis, transfer hepatocellular, etc. Meanwhile, the mechanism for the determination of G with AA-SS-RTP was discussed.

Antigenic properties of the envelope of influenza virus rendered soluble by surfactant-solvent systems

PubMed Central

Larin, N. M.; Gallimore, P. H.

1971-01-01

Dissociating chemical treatments employing surfactant-solvent systems were applied to purified influenza A and B viruses to obtain viral preparations possessing a significantly higher or lower haemagglutinating activity than the intact virus. All preparations, whether with high or low haemagglutinating activity, with the exception of envelope protein solubilized by Triton X-100, were significantly lacking in the ability to excite the formation of haemagglutination-inhibiting and virus-neutralizing antibodies in inoculated ferrets. In contrast to other treatments, Triton X-100 treatment of virus significantly enhanced the antigenicity of viral protein as judged by virus neutralization and haemagglutination inhibition tests. Yet the haemagglutinating activity of the envelope protein solubilized with Triton X-100 was about 1% that of the intact virus. Results suggest that the correlation assumed to exist between the haemagglutinating activity of influenza virus and its ability to excite the formation of humoral antibodies is coincidental. Another important point is that the specific antigenicity of viral protein may be lost or enhanced owing to effects, other than solubilization, by surface-active agents. PMID:5291750

Determination of xanthohumol in beer based on cloud point extraction coupled with high performance liquid chromatography.

PubMed

Chen, Ligang; Zhao, Qi; Jin, Haiyan; Zhang, Xiaopan; Xu, Yang; Yu, Aimin; Zhang, Hanqi; Ding, Lan

2010-04-15

A method based on coupling of cloud point extraction (CPE) with high performance liquid chromatography separation and ultraviolet detection was developed for determination of xanthohumol in beer. The nonionic surfactant Triton X-114 was chosen as the extraction medium. The parameters affecting the CPE were evaluated and optimized. The highest extraction yield of xanthohumol was obtained with 2.5% of Triton X-114 (v/v) at pH 5.0, 15% of sodium chloride (w/v), 70 degrees C of equilibrium temperature and 10 min of equilibrium time. Under these conditions, the limit of detection of xanthohumol is 0.003 mg L(-1). The intra- and inter-day precisions expressed as relative standard deviations are 4.6% and 6.3%, respectively. The proposed method was successfully applied for determination of xanthohumol in various beer samples. The contents of xanthohumol in these samples are in the range of 0.052-0.628 mg L(-1), and the recoveries ranging from 90.7% to 101.9% were obtained. The developed method was demonstrated to be efficient, green, rapid and inexpensive for extraction and determination of xanthohumol in beer. (c) 2010 Elsevier B.V. All rights reserved.

Opposite behavior of two isozymes when refolding in the presence of non-ionic detergents.

PubMed Central

Doñate, F.; Artigues, A.; Iriarte, A.; Martinez-Carrion, M.

1998-01-01

GroEL has a greater affinity for the mitochondrial isozyme (mAAT) of aspartate aminotransferase than for its cytosolic counterpart (cAAT) (Mattingly JR Jr, Iriarte A, Martinez-Carrion M, 1995, J Biol Chem 270:1138-1148), two proteins that share a high degree of sequence similarity and an almost identical spatial structure. The effect of detergents on the refolding of these large, dimeric isozymes parallels this difference in behavior. The presence of non-ionic detergents such as Triton X-100 or lubrol at concentrations above their critical micelle concentration (CMC) interferes with reactivation of mAAT unfolded in guanidinium chloride but increases the yield of cAAT refolding at low temperatures. The inhibitory effect of detergents on the reactivation of mAAT decreases progressively as the addition of detergents is delayed after starting the refolding reaction. The rate of disappearance of the species with affinity for binding detergents coincides with the slowest of the two rate-limiting steps detected in the refolding pathway of mAAT. Limited proteolysis studies indicate that the overall structure of the detergent-bound mAAT resembles that of the protein in a complex with GroEL. The mAAT folding intermediates trapped in the presence of detergents can resume reactivation either upon dilution of the detergent below its CMC or by adding beta-cyclodextrin. Thus, isolation of otherwise transient productive folding intermediates for further characterization is possible through the use of detergents. PMID:10082379

Opposite behavior of two isozymes when refolding in the presence of non-ionic detergents.

PubMed

Doñate, F; Artigues, A; Iriarte, A; Martinez-Carrion, M

1998-08-01

GroEL has a greater affinity for the mitochondrial isozyme (mAAT) of aspartate aminotransferase than for its cytosolic counterpart (cAAT) (Mattingly JR Jr, Iriarte A, Martinez-Carrion M, 1995, J Biol Chem 270:1138-1148), two proteins that share a high degree of sequence similarity and an almost identical spatial structure. The effect of detergents on the refolding of these large, dimeric isozymes parallels this difference in behavior. The presence of non-ionic detergents such as Triton X-100 or lubrol at concentrations above their critical micelle concentration (CMC) interferes with reactivation of mAAT unfolded in guanidinium chloride but increases the yield of cAAT refolding at low temperatures. The inhibitory effect of detergents on the reactivation of mAAT decreases progressively as the addition of detergents is delayed after starting the refolding reaction. The rate of disappearance of the species with affinity for binding detergents coincides with the slowest of the two rate-limiting steps detected in the refolding pathway of mAAT. Limited proteolysis studies indicate that the overall structure of the detergent-bound mAAT resembles that of the protein in a complex with GroEL. The mAAT folding intermediates trapped in the presence of detergents can resume reactivation either upon dilution of the detergent below its CMC or by adding beta-cyclodextrin. Thus, isolation of otherwise transient productive folding intermediates for further characterization is possible through the use of detergents.

Influenza Virus Inactivation for Studies of Antigenicity and Phenotypic Neuraminidase Inhibitor Resistance Profiling ▿

PubMed Central

Jonges, Marcel; Liu, Wai Ming; van der Vries, Erhard; Jacobi, Ronald; Pronk, Inge; Boog, Claire; Koopmans, Marion; Meijer, Adam; Soethout, Ernst

2010-01-01

Introduction of a new influenza virus in humans urges quick analysis of its virological and immunological characteristics to determine the impact on public health and to develop protective measures for the human population. At present, however, the necessity of executing pandemic influenza virus research under biosafety level 3 (BSL-3) high-containment conditions severely hampers timely characterization of such viruses. We tested heat, formalin, Triton X-100, and β-propiolactone treatments for their potencies in inactivating human influenza A(H3N2) and avian A(H7N3) viruses, as well as seasonal and pandemic A(H1N1) virus isolates, while allowing the specimens to retain their virological and immunological properties. Successful heat inactivation coincided with the loss of hemagglutinin (HA) and neuraminidase (NA) characteristics, and β-propiolactone inactivation reduced the hemagglutination titer and NA activity of the human influenza virus 10-fold or more. Although Triton X-100 treatment resulted in inconsistent HA activity, the NA activities in culture supernatants were enhanced consistently. Nonetheless, formalin treatment permitted the best retention of HA and NA properties. Triton X-100 treatment proved to be the easiest-to-use influenza virus inactivation protocol for application in combination with phenotypic NA inhibitor susceptibility assays, while formalin treatment preserved B-cell and T-cell epitope antigenicity, allowing the detection of both humoral and cellular immune responses. In conclusion, we demonstrated successful influenza virus characterization using formalin- and Triton X-100-inactivated virus samples. Application of these inactivation protocols limits work under BSL-3 conditions to virus culture, thus enabling more timely determination of public health impact and development of protective measures when a new influenza virus, e.g., pandemic A(H1N1)v virus, is introduced in humans. PMID:20089763

Generation and stabilization of whey-based monodisperse naoemulsions using ultra-high pressure homogenization and small amphipathic co-emulsifier combinations

USDA-ARS?s Scientific Manuscript database

Ultra-high-pressure homogenization (UHPH) was used to generate monodisperse stable peanut oil nanoemulsions within a desired nanosize range (<100 nm) (DNR) stabilized using combinations of whey protein concentrate (WPC), sodium dodecyl sulfate, Triton X-100 (X100), and zwitterionic sulfobetaine-base...

Hyperbranched epoxy/MWCNT-CuO-nystatin nanocomposite as a high performance, biocompatible, antimicrobial material

NASA Astrophysics Data System (ADS)

Barua, Shaswat; Chattopadhyay, Pronobesh; Phukan, Mayur M.; Konwar, Bolin K.; Karak, Niranjan

2014-12-01

Hyperbranched epoxy MWCNT-CuO-nystatin nanocomposite has been presented here as an advanced antimicrobial high performance material. The material showed significant improvement of mechanical properties (tensile strength from 38 to 63 MPa) over the pristine matrix without effecting elongation. MWCNT was modified by a non-ionic surfactant, triton X-100, wherein copper oxide nanoparticles were anchored in situ by a ‘green’ method. Further, sonochemical immobilization of nystatin enhanced the stability of the system. The immobilized nanohybrid system was incorporated into the hyperbranched matrix in 1, 2 and 3 wt%. The resultant system proved its ability to prevent bacterial, fungal and microalgal fouling against the tested strains, Staphylococcus aureus, Candida albicans and Chlorella sp. Additionally, this system is quite compatible with rat heart cells. Furthermore, in vivo assessment showed that this could be utilized as an implantable antimicrobial biomaterial. Thus, the overall study pointed out that the prepared material may have immense utility in marine industry as well as in biomedical domain to address microbial fouling, without inducing any toxicity to higher organisms.

Comparison of amphiphilic polyurethane nanoparticles to nonionic surfactants for flushing phenanthrene from soil.

PubMed

Kim, Ju-Young; Shim, Sun-Bo; Shim, Jin-Kie

2004-12-31

Amphiphilic polyurethane (APU) nanoparticles were synthesized through crosslinking polymerization of nano-aggregates of urethane acrylate nonionomer (UAN). The efficiency of in situ extraction of sorbed phenanthrene from aquifer material was tested using soil columns and compared with that of surfactants such as Triton X-100, Brij 30, and Tween 80. The extraction efficiency of those washing materials strongly depended on their concentration, flow rate, and the degree of sorption within soil column. That is, the extraction efficiency increased with the decrease of flow rate and the degree of sorption and the increase of the concentration. Even though the surfactants are superior to APU nanoparticles at solubilizing phenanthrene, at the same flow rate (0.02 mL/min) and concentration (4000 mg/L), the effectiveness of in situ soil washing of APU nanoparticles was about two times higher than those of surfactants. This is because, at the lower flow rates, the degree of sorption of APU nanoparticles was lower than that of surfactants, owing to the chemically crosslinked nature of APU nanoparticles.

Spectrofluorimetric study on the inclusion interaction between vitamin K 3 with p-( p-sulfonated benzeneazo)calix[6]arene and determination of VK 3

NASA Astrophysics Data System (ADS)

Zhou, Yunyou; Xu, Hongwei; Wu, Lian; Liu, Chun; Lu, Qin; Wang, Lun

2008-11-01

The characteristics of host-guest complexation between p-( p-sulfonated benzeneazo) calix[6]arene (SBC6A) and vitamin K 3 (VK 3) were investigated by fluorescence spectrometry. A 1:1 stoichiometry for the complexation was established and was verified by Job's plot. An association constant of 4.95 × 10 3 L mol -1 at 20 °C was calculated by applying a deduced equation. The interaction mechanism of the inclusion complex was discussed. It was found that the fluorescence of SBC6A could be remarkably quenched by an appropriate amount of VK 3 especially when non-ionic surfactant Triton X-100 existed. According to the obtained results, a novel sensitive spectrofluorimetric method for the determination of VK 3 based on supramolecular complex was developed with a linear range of 5.0 × 10 -7-3.0 × 10 -5 mol L -1 and a detection limit of 2.0 × 10 -7 mol L -1. The proposed method was used to determine VK 3 in commercial preparations with satisfactory results.

Rapid determination of surfactant critical micelle concentration in aqueous solutions using fiber-optic refractive index sensing.

PubMed

Tan, Chun Hua; Huang, Zhen Jian; Huang, Xu Guang

2010-06-01

We describe a simple and rapid method for determining the critical micelle concentration (CMC) of surfactants from fiber-optic measurements of refractive index. The refractive index of an aqueous surfactant solution was monitored as the surfactant concentration was increased using an automated dispensing system. On reaching the surfactant's CMC value, an abrupt change was observed in the rate of increase of the refractive index with increasing concentration. The measurement system provides rapid semiautomatic data collection and analysis, increasing the precision, sensitivity, and range of applicability of the technique while substantially decreasing the amount of manual intervention required. Measurements of CMC for sodium dodecyl sulfate (8.10mM), cetyltrimethylammonium chloride (1.58mM), and Triton X-100 (0.21mM) were in excellent agreement with values previously reported in the literature. The method is applicable to cationic, anionic, and nonionic surfactants, and it offers a facile, in situ, and sensitive means of detecting micelle formation over a broad range of CMC values larger than 10(-1)mM. Copyright 2010 Elsevier Inc. All rights reserved.

Immunoblot detection of class-specific humoral immune response to outer membrane proteins isolated from Salmonella typhi in humans with typhoid fever.

PubMed Central

Ortiz, V; Isibasi, A; García-Ortigoza, E; Kumate, J

1989-01-01

The studies reported here were undertaken to assess the ability of the outer membrane proteins (OMPs) of Salmonella typhi to induce a humoral immune response in humans with typhoid fever. OMPs were isolated with the nonionic detergent Triton X-100 and were found to be contaminated with approximately 4% lipopolysaccharide. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns showed protein bands with molecular size ranges from 17 to 70 kilodaltons; the major groups of proteins were those that correspond to the porins and OmpA of gram-negative bacteria. Rabbit antiserum to OMPs or to S. typhi recognized OMPs after absorption with lipopolysaccharide. Sera from patients with typhoid fever contained immunoglobulin M antibodies which reacted with a protein of 28 kilodaltons and immunoglobulin G antibodies which reacted mainly with the porins, as determined by immunoblotting. These results indicate that the porins are the major immunogenic OMPs from S. typhi and that the immune response induced in the infection could be related to the protective status. Images PMID:2768450

[Effect of Triton X-100 on genetic segregation and associated monocotyledonous and dicotyledonous traits in sugarbeet (Beta vulgaris L.)].

PubMed

Kirikovich, S S; Levites, E V

2013-05-01

The effect of Triton X-100 (TX-100) on the ratio of phenotypic classes and the expression of morphological traits in the progeny of sugar beet hybrids (N12 and N2) was investigated. It was shown that the TX-100 exposition on the unopened flower buds of sugar beets has different effects on hybrid progenies. In agamospermic progeny of hybrid plant No 12km-4, a significant decrease in the heteroallelic (heterozygous) phenotypic classes of alcohol dehydrogenase (ADH1) fraction was determined in the nonagamospermic progeny of hybrid plant No 2km-2 appearance of sugar beet seedlings with one cotyledon leaf was detected. The obtained results indicate the high efficiency of the epimutagenic effect of TX-100 on the early stages of plant ontogenesis.

Effect of surfactants and natural detergents on phosphatidylcholine synthesis in photoreceptor membranes.

PubMed

Roque, M E; Castagnet, P I; Giusto, N M

2001-07-01

The synthesis of phosphatidylcholine (PC) in rod outer segments (ROS) catalysed by lysophosphatidylcholine acyltransferase and phosphatidylethanolamine N-methyltransferase (PE N-MTase) was studied and the effects of natural (FA and lysophospholipids) and synthetic (Triton X-100, deoxycholate and CHAPS) surfactants was evaluated. In all experimental conditions used, incorporation of labelled oleate into lysophosphatidylcholine (lysoPC) was at least 40 times greater than oleate incorporation into any other lysophospholipid. Acylation of lysoPC was slightly affected by Triton X-100 and was totally inhibited in the presence of 10 mM sodium deoxycholate (NaDOC) or CHAPS. Below their critical micelle concentration (cmc) Triton X-100 and NaDOC stimulated acylation of all ROS lysophospholipids analysed. The activity of PE N-MTase was stimulated at detergent concentrations below the cmc and inhibited at concentrations above the cmc for all three detergents tested. The effect of FA with differing degree of unsaturation on PC synthesis was evaluated. Oleic acid (10 microM) inhibited methyl group incorporation into total PC, whereas from 100 microM onward, the methylating activity increased with preferential synthesis of PC. Docosahexaenoic acid, in turn, inhibited PE N-MTase activity at every concentration tested. These results suggest that PC synthesis in ROS membranes is modified by bioregulators and surfactants altering the physico-chemical state of the membrane.

Trypsin digestion for determining orientation of ATPase in Halobacterium saccharovorum membrane vesicles

NASA Technical Reports Server (NTRS)

Kristjansson, H.; Hochstein, L. I.

1986-01-01

Membranes prepared by low pressure disruption of cells exhibited no ATPase activity in the absence of Triton X-100, although 43% of the total menadione reductase activity was detected. Trypsin digestion reduced menadione reductase activity by 45% whereas ATPase activity was not affected. Disruption of the membrane fraction at higher pressure solubilized about 45% of the ATPase activity. The soluble activity was still enhanced by Triton X-100, suggesting that the detergent, besides disrupting membrane vesicles, also activated the ATPase. The discrepancy in localization of menadione reductase and ATPase activities raised questions regarding the reliability of using a single marker enzyme as an indicator of vesicle orientation.

External and Intraparticle Diffusion of Coumarin 102 with Surfactant in the ODS-silica Gel/water System by Single Microparticle Injection and Confocal Fluorescence Microspectroscopy.

PubMed

Nakatani, Kiyoharu; Matsuta, Emi

2015-01-01

The release mechanism of coumarin 102 from a single ODS-silica gel microparticle into the water phase in the presence of Triton X-100 was investigated by confocal fluorescence microspectroscopy combined with the single microparticle injection technique. The release rate significantly depended on the Triton X-100 concentration in the water phase and was not limited by diffusion in the pores of the microparticle. The release rate constant was inversely proportional to the microparticle radius squared, indicating that the rate-determining step is the external diffusion between the microparticle and the water phase.

The relationship of detergent-solubilization plasma-membrane components of rabbit alveolar macrophages to an isolated inhibitor of phagocytosis.

PubMed Central

Pratt, R S; Cook, G M

1979-01-01

1. A plasma-membrane fraction prepared from rabbit alveolar macrophages by hyposmotic borate lysis is described. 2. Rabbit lung lavages, containing a glycoprotein inhibitor of phagocytosis, may be fractionated by preparative isoelectric focusing in the presence of Triton X-100. 3. Chemical analysis indicates that the glycoproteins of the lung lavage contain sialic acid, fucose, mannose, galactose, hexosamine and appreciable quantities of glucose. 4. The relationship of macrophage membrane glycoproteins, solubilized with Triton X-100 in the presence of borate, to the lung lavage glycoproteins is demonstrated immunoelectrophoretically. Images PLATE 1 Fig. 1. Fig. 2. PMID:486083

Effect of additives on the clouding and aggregation behavior of Triton X-100

NASA Astrophysics Data System (ADS)

Semwal, Divyam; Sen, Indrani Das; Jayaram, Radha V.

2018-04-01

The present study investigates the effect of additives such as CsNO3 and imidazolium ionic liquids on the cloud point (CP) of Triton X-100. Thermodynamic parameters of the clouding process were determined in order to understand the interactions. CP was found to increase with the increase in concentration of most of the ionic liquids studied. This increase of CP reflects the solubilization of the ionic liquids in the micellar phase1. The thermodynamic parameters on the introduction of CsNO3 in TX-100 - ionic liquid system helps in understanding the different interactions occurring in the system. All ΔG values for clouding were found to be positive and hence made the process non spontaneous.

Atrazine and Diuron partitioning within a soil-water-surfactant system

NASA Astrophysics Data System (ADS)

Wang, P.; Keller, A.

2006-12-01

The interaction between pesticide and soil and water is even more complex in the presence of surfactants. In this study, batch equilibrium was employed to study the sorption of surfactants and the partitioning behaviors of Atrazine and Diuron within a soil-water-surfactant system. Five soils and four surfactants (nonionic Triton- 100, cationic Benzalkonium Chloride (BC), anionic Linear Alkylbenzenesulfonate (LAS), and anionic Sodium Dodecyl Sulfate (SDS)) were used. All surfactant sorption isotherms exhibited an initial linear increase at low surfactant concentrations but reached an asymptotic value as the surfactant concentrations increased. Among the surfactants, BC had the highest sorption onto all soils, followed by Triton-100 and then by LAS and SDS, implying that the nature of the charge significantly influences surfactant sorption. Sorption of either Triton-100 or BC was highly correlated with soil Cation Exchange Capacity (CEC) while that of LAS and SDS was complicated by the presence of Ca2+ and Mg2+ in the aqueous phase and the CEC sites. Both LAS and SDS formed complexes with Ca2+ and Mg2+, resulting in a significant decrease in the detergency of the surfactants. At high surfactant concentrations and with micelles present in the aqueous phase, the micelles formed a more competitive partitioning site for the pesticides, resulting in less pesticide sorbed to the soil. At low Triton-100 and BC concentration, the sorption of the surfactants first resulted in less Atrazine sorption but more Diuron sorption, implying competition between the surfactants and Atrazine, which serves as an indirect evidence that there is a different sorption mechanism for Atrazine. Atrazine is a weak base and it protonates and becomes positively charged near particle surfaces where the pH is much lower than in the bulk solution. The protonated Atrazine may then be held on the CEC sites via electrostatic attraction. Triton-100, LAS and SDS sorbed on the soil showed similar sequestration efficiency for Atrazine and Diuron while BC sorbed on the soils with lower CECs showed much higher Atrazine and Diuron sequestration efficiency than the other surfactants, suggesting that the sorbed BC on these soils with less CEC forms bulk-like partitioning media more easily than the soils with higher CECs. These results significantly improve our understanding of partitioning of pesticides within soil-water-surfactant systems. These findings can serve to improve the pesticide removal efficiency of soil washing systems. Also, our results show that by studying the effect of surfactants on pesticide sorption can serve as a new method to study pesticide sorption mechanisms.

Effect of surfactants on weight gain in mice.

PubMed

Kaneene, J B; Ross, R W

1986-03-01

A study was conducted to determine if four surfactants can induce increased weight gain in the mouse. Basic-H, Triton X-100, Amway All Purpose Adjuvant and X-77 were put in water and fed to various groups of ICR 21 day old female mice for a period of 43 days. All the mice were clinically normal throughout the study period. Pathological examination of a random sample of the mice revealed no gross pathological changes. Similarly, histopathological examination of the lungs, livers and intestines did not reveal any visible lesions. Basic-H and Amway surfactants induced weight gain, though not significantly, better at 0.1% (V/V) concentration while X-77 and Triton X-100 induced weight gain better at 0.4% (V/V) concentration. Overall results show that none of the surfactants tested induced significant weight gain.

Determination of Prometryne in water and soil by HPLC-UV using cloud-point extraction.

PubMed

Zhou, Jihai; Chen, Jiandong; Cheng, Yanhong; Li, Daming; Hu, Feng; Li, Huixin

2009-07-15

A CPE-HPLC (UV) method has been developed for the determination of Prometryne. In this method, non-ionic surfactant Triton X-114 was first used to extract and pre-concentrate Prometryne from water and soil samples. The separation and determination of Prometryne were then carried out in an HPLC-UV system with isocratic elution using a detector set at 254 nm wavelength. The parameters and variables that affected the extraction were also investigated and the optimal conditions were found to be 0.5% of Triton X-114 (w/v), 3% of NaCl (w/v) and heat-assisted at 50 degrees C for 30 min. Using these conditions, the recovery rates of Prometryne ranged from 92.84% to 99.23% in water and 85.48% to 93.67% in soil, respectively, with all the relative standard deviations less than 3.05%. Limit of detection (LOD) and limit of quantification (LOQ) were 3.5 microg L(-1) and 11.0 microg L(-1) in water and 4.0 microg kg(-1) and 13.0 microg kg(-1) in soil, respectively. Thus, we developed a method that has proven to be an efficient, green, rapid and inexpensive approach for extraction and determination of Prometryne from soil samples.

A green method using a micellar system for determination of andrographolide and dehydroandrographolide in human plasma.

PubMed

Zhao, Qi; Ding, Jie; Jin, Haiyan; Ding, Lan; Ren, Nanqi

2013-04-01

A method based on cloud point extraction (CPE) coupled with high-performance liquid chromatography separation and ultraviolet (UV) detection was developed to determine andrographolide and dehydroandrographolide in human plasma. The nonionic surfactant Triton X-114 was chosen as the extraction medium. Variable parameters affecting the CPE efficiency were evaluated and optimized, such as concentrations of Triton X-114 and NaCl, pH, equilibration temperature and equilibration time. A Zorbax SB C18 column (250 × 4.6 mm i.d., 5 µm) was used for separation of the two analytes at 30°C. The UV detection was performed at 254 nm. Under the optimum conditions, the limits of detection of andrographolide and dehydroandrographolide are 0.032 and 0.019 µg/mL, respectively. The intra-day and inter-day precisions expressed as relative standard deviation ranged from 3.2 to 7.3% and from 2.9 and 8.6%. The recoveries of andrographolide and dehydroandrographolide were in the range of 76.8-98.6% at three fortified concentrations of 0.1, 0.5 and 1.0 µg/mL. This method was efficient, environmentally friendly, rapid and inexpensive for the extraction and determination of andrographolide and dehydroandrographolide in human plasma.

Effects of surfactants on low-molecular-weight organic acids to wash soil zinc.

PubMed

Chen, Yue; Zhang, Shirong; Xu, Xiaoxun; Yao, Ping; Li, Ting; Wang, Guiyin; Gong, Guoshu; Li, Yun; Deng, Ouping

2016-03-01

Soil washing is an effective approach to the removal of heavy metals from contaminated soil. In this study, the effects of the surfactants sodium dodecyl sulfate, Triton X-100, and non-ionic polyacrylamide (NPAM) on oxalic acid, tartaric acid, and citric acid used to remove zinc from contaminated soils were investigated. The Zn removal efficiencies of all washing solutions showed a logarithmic increase with acid concentrations from 0.5 to 10.0 g/L, while they decreased as pH increased from 4 to 9. Increasing the reaction time enhanced the effects of surfactants on Zn removal efficiencies by the acids during washing and significantly (P < 0.05) improved the removal under some mixed cases. Oxalic acid suffered antagonistic effects from the three surfactants and seriously damaged soil nutrients during the removal of soil Zn. Notably, the three surfactants caused synergistic effects on tartaric and citric acid during washing, with NPAM leading to an increase in Zn removal by 5.0 g/L citric acid of 10.60 % (P < 0.05) within 2 h. NPAM also alleviated the loss of cation exchange capacity of washed soils and obviously improved soil nitrogen concentrations. Overall, combining citric acid with NPAM offers a promising approach to the removal of zinc from contaminated soil.

Greatly decreased susceptibility of nonmetabolizing cells towards detergents.

PubMed Central

Komor, E; Weber, H; Tanner, W

1979-01-01

The addition of different detergents to Chlorella cells that had previously accumulated 6-deoxyglucose causes a rapid release of the hexose analogue into the medium. This effect is independent of the nature of the detergent and is observed only when the cells are in an energized state. Thus, in the presence of the uncoupler p-trifluoromethoxycarbonylcyanide phenylhydrazone or of inhibitors such as N-ethylmaleimide, the cells show a greatly reduced susceptibility towards detergents. Similarly, the detergent-induced loss of accumulated alpha-aminoisobutyric acid from Saccharomyces cerevisiae and of potassium from Escherichia coli is also strongly affected by the energy state of the cells. The differential susceptibility of energized and nonenergized cells was observed at all detergent concentrations tested. Measurements of substrate efflux at different concentrations of Triton indicated that only Triton monomers are responsible for the increase in permeability. The absorption of [14C]Triton X-100 by Chlorella and the binding of detergent to the cells were measured in the presence of metabolic inhibitors. Again, nonenergized cells bound a significantly lower amount of Triton X-100. The amphiphilic antibiotic nystatin produced effects on cell permeability similar to those of detergents, whereas toluene, which is apolar, gave opposite results. PMID:377284

Tips on the analysis of phosphatidic acid by the fluorometric coupled enzyme assay.

PubMed

Hassaninasab, Azam; Han, Gil-Soo; Carman, George M

2017-06-01

The fluorometric coupled enzyme assay to measure phosphatidic acid (PA) involves the solubilization of extracted lipids in Triton X-100, deacylation, and the oxidation of PA-derived glycerol-3-phosphate to produce hydrogen peroxide for conversion of Amplex Red to resorufin. The enzyme assay is sensitive, but plagued by high background fluorescence from the peroxide-containing detergent and incomplete heat inactivation of lipoprotein lipase. These problems affecting the assay reproducibility were obviated by the use of highly pure Triton X-100 and by sufficient heat inactivation of the lipase enzyme. The enzyme assay could accurately measure the PA content from the subcellular fractions of yeast cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Protochlorophyll complexes with similar steady-state fluorescence characteristics can differ in fluorescence lifetimes. A model study in Triton X-100.

PubMed

Myśliwa-Kurdziel, Beata; Solymosi, Katalin; Kruk, Jerzy; Böddi, Béla; Strzałka, Kazimierz

2007-03-01

The steady-state and time-resolved fluorescence characteristics of protochlorophyll (Pchl) dissolved in neat Triton X-100 and in Triton X-100 micelles were investigated, and the fluorescence lifetimes of different Pchl spectral forms were studied. Varying the concentration of Pchl or diluting the micellar solutions either with a buffer or with a micellar solution, 631-634, 645-655, 680-692 and above 700 nm emitting Pchl complexes were prepared, the ratios of which varied from one another. The fluorescence decay of the 631-634 nm emitting (monomeric) form had a mono-exponential character with a 5.4-ns fluorescence lifetime. The long-wavelength Pchl complexes (aggregates) had two fluorescence lifetime values within a range of 1.4-3.9 ns and 0.15-0.84 ns, which showed high variability in different environments. Depending on the conditions, either mono- or double-exponential fluorescence decay was found for a fluorescence band at 680-685 nm. These data show that despite their very similar steady-state fluorescence properties, Pchl complexes can differ in fluorescence lifetimes, which may reflect different molecular structures, intrinsic geometries or different molecular interactions. This underlines the importance of complex spectroscopic analysis for a precise description of native and artificial chlorophyllous pigment forms.

Preparation of membrane rafts.

PubMed

Waugh, Mark G; Hsuan, J Justin

2009-01-01

The concept that biological membranes contain microdomains of specialized lipid and protein composition has attracted great attention in recent years. Initially, the focus in the field was very much on the characterization of cholesterol-and sphingolipid-rich plasma membrane microdomains that were resistant to solubilization in the cold non-ionic detergent Triton X-100. Such detergent-insoluble membrane domains were of low buoyant density and could be readily purified on sucrose equilibrium density gradients. The intrinsic buoyancy of the detergent-insoluble domains gave rise to the term "lipid rafts." Cholesterol- and sphingolipid-rich rafts at the plasma membrane have been implicated in a wide range of cellular processes, including pathogen invasion, receptor signaling, and endocytosis. However, work with other non-ionic detergents such as Lubrol WX and Brij-98 has revealed the existence of various raft subtypes with differing lipid compositions and proposed functions. More recently, there has been some focus on isolating lipid rafts from intracellular organelles, in particular membranes from the Golgi-endosomal pathway, where raft lipids have been proposed to function in processes such as the sorting of vesicular cargo and the processing of amyloid precursor protein. While there remains a large degree of controversy surrounding the purity, the physiological importance, and even the existence of different types of lipid rafts in intact cells, the ability to routinely purify such domains has led to significant progress in understanding the functional architecture of biological membranes. We describe a number of widely used methods to prepare rafts, based on early preparations of caveolae by density gradient ultracentrifugation and immunoaffinity precipitation.

Surfactant toxicity to Artemia Franciscana and the influence of humic acid and chemical composition

PubMed Central

Deese, Rachel D.; LeBlanc, Madeline R.

2016-01-01

Surfactants can be extremely toxic to aquatic species and are introduced to the environment in a variety of ways. It is thus important to understand how other environmental constituents, in this case humic acids (HAs), may alter the toxicity of anthropogenic surfactants. Hatching and mortality assays of Artemia Franciscana were performed for three different toxic surfactants: Triton X-100 (Tx-100, non-ionic), cetylpyridinium chloride (CPC, cationic), and sodium dodecyl sulfate (SDS, anionic). Humic acids of varying composition and concentrations were added to the assays to determine the toxicity mitigating ability of the HAs. Tx-100 had a significant toxic effect on Artemia mortality rates and HAs from terrestrial sources were able to mitigate the toxicity, but an aquatic HA did not. CPC and SDS limited hatching success of the Artemia and, as HAs were added, the hatching percentages increased for all HA sources, indicating toxicity mitigation. In order to determine which functional groups within HAs were responsible for the interaction with the surfactants, the HAs were chemically modified by: (i) bleaching to reduce aromatics, (ii) Soxhlet extraction to reduce lipids, and (iii) acid hydrolysis to reduce O- and N-alkyl groups. Although most of the modified HAs had some toxicity mitigating ability for each of the surfactants, there were two notable differences: 1) the lipid-extracted HA did not reduce the toxicity of Tx-100 and 2) the bleached HA had a lower toxicity mitigating ability for CPC than the other modified HAs. PMID:27453688

The solubilisation of boar sperm membranes by different detergents - a microscopic, MALDI-TOF MS, 31P NMR and PAGE study on membrane lysis, extraction efficiency, lipid and protein composition

PubMed Central

2009-01-01

Background Detergents are often used to isolate proteins, lipids as well as "detergent-resistant membrane domains" (DRMs) from cells. Different detergents affect different membrane structures according to their physico-chemical properties. However, the effects of different detergents on membrane lysis of boar spermatozoa and the lipid composition of DRMs prepared from the affected sperm membranes have not been investigated so far. Results Spermatozoa were treated with the selected detergents Pluronic F-127, sodium cholate, CHAPS, Tween 20, Triton X-100 and Brij 96V. Different patterns of membrane disintegration were observed by light and electron microscopy. In accordance with microscopic data, different amounts of lipids and proteins were released from the cells by the different detergents. The biochemical methods to assay the phosphorus and cholesterol contents as well as 31P NMR to determine the phospholipids were not influenced by the presence of detergents since comparable amounts of lipids were detected in the organic extracts from whole cell suspensions after exposure to each detergent. However, matrix-assisted laser desorption and ionization time-of-flight mass spectrometry applied to identify phospholipids was essentially disturbed by the presence of detergents which exerted particular suppression effects on signal intensities. After separation of the membrane fractions released by detergents on a sucrose gradient only Triton X-100 and sodium cholate produced sharp turbid DRM bands. Only membrane solubilisation by Triton X-100 leads to an enrichment of cholesterol, sphingomyelin, phosphatidylinositol and phosphatidylethanolamine in a visible DRM band accompanied by a selective accumulation of proteins. Conclusion The boar sperm membranes are solubilised to a different extent by the used detergents. Particularly, the very unique DRMs isolated after Triton X-100 exposure are interesting candidates for further studies regarding the architecture of sperm. PMID:19906304

IR spectroscopy analysis of pancreatic lipase-related protein 2 interaction with phospholipids: 2. Discriminative recognition of various micellar systems and characterization of PLRP2-DPPC-bile salt complexes.

PubMed

Mateos-Diaz, Eduardo; Sutto-Ortiz, Priscila; Sahaka, Moulay; Byrne, Deborah; Gaussier, Hélène; Carrière, Frédéric

2018-03-01

The interaction of pancreatic lipase-related protein 2 (PLRP2) with various micelles containing phospholipids was investigated using pHstat enzyme activity measurements, differential light scattering, size exclusion chromatography (SEC) and transmission IR spectroscopy. Various micelles of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and lysophosphatidylcholine were prepared with either bile salts (sodium taurodeoxycholate or glycodeoxycholate) or Triton X-100, which are substrate-dispersing agents commonly used for measuring phospholipase activities. PLRP2 displayed a high activity on all phospholipid-bile salt micelles, but was totally inactive on phospholipid-Triton X-100 micelles. These findings clearly differentiate PLRP2 from secreted pancreatic phospholipase A2 which is highly active on both types of micelles. Using an inactive variant of PLRP2, SEC experiments allowed identifying two populations of PLRP2-DPPC-bile salt complexes corresponding to a high molecular weight 1:1 PLRP2-micelle association and to a low molecular weight association of PLRP2 with few monomers of DPPC/bile salts. IR spectroscopy analysis showed how DPPC-bile salt micelles differ from DPPC-Triton X-100 micelles by a higher fluidity of acyl chains and higher hydration/H-bonding of the interfacial carbonyl region. The presence of bile salts allowed observing changes in the IR spectrum of DPPC upon addition of PLRP2 (higher rigidity of acyl chains, dehydration of the interfacial carbonyl region), while no change was observed with Triton X-100. The differences between these surfactants and their impact on substrate recognition by PLRP2 are discussed, as well as the mechanism by which high and low molecular weight PLRP2-DPPC-bile salt complexes may be involved in the overall process of DPPC hydrolysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Oil-in-water nanocontainers as low environmental impact cleaning tools for works of art: two case studies.

PubMed

Carretti, Emiliano; Giorgi, Rodorico; Berti, Debora; Baglioni, Piero

2007-05-22

A novel class of p-xylene-in-water microemulsions mainly based on nonionic surfactants and their application as low impact cleaning tool in cultural heritage conservation is presented. Alkyl polyglycosides (APG) and Triton X-100 surfactants allow obtaining very effective low impact oil-in-water (o/w) microemulsions as alternatives to pure organic solvents for the removal of polymers (particularly Paraloid B72 and Primal AC33) applied during previous conservation treatments. The ternary APG/p-xylene/water microemulsions have been characterized by quasi elastic light scattering to obtain the hydrodynamic radius and the polydispersity of the microemulsion droplets. Laplace inversion of the correlation function CONTIN analysis provided evidence of acrylic copolymers solubilization into the oil nanodroplets. Contact angle, Fourier transform infrared (FTIR), and scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) data confirmed that microemulsions were effective in removing polymer coatings. The phase diagram of APG microemulsions showed that a reduction >90% (compared to the conventional cleaning methods) of the organic solvent can be achieved by using o/w microemulsions. The microemulsions were successfully tested in two real cases: (1) the APG based microemulsion was used in a Renaissance painting by Vecchietta in Santa Maria della Scala, Siena, Italy, degraded by the presence of a polyacrylate coating applied during a previous restoration and (2) a Triton X-100 oil-in-water microemulsion containing (NH4)2CO3 in the water continuous phase. The association of ammoniun carbonate to the microemusion led to the swelling of an organic deposit (mainly asphaltenes deposited on the fresco in the Oratorio di San Nicola al Ceppo in Florence, still contamined by the water of the Arno river during the 1966 flood) and a very efficient removal of highly insoluble inorganic deposits (mainly gypsum) strongly associated to asphaltenes. These innovative systems are very attractive for the low amount of organic solvent used to extract the polymers or highly insoluble substances as the asphaltene and the very efficient and mild impact of the cleaning procedure on the fragile painted surfaces.

The reversed-flow gas chromatography technique as a tool for the study of the evaporation retardation of SO2 and (CH3)2S from water by soluble surfactants.

PubMed

Sevastos, D; Kotsalos, E; Koliadima, A

2017-02-01

In the present work the evaporation retardation of SO 2 and (CH 3 ) 2 S (=DMS) from water by soluble surfactants was studied by the Reversed-Flow Gas Chromatography (R.F.G.C.) technique. Using suitable mathematical analysis, rate coefficients, k c , for the transfer of SO 2 and DMS from pure or artificial sea water to the atmospheric environment were determined in the presence or the absence of surfactants. The efficiency of the three surfactants used (CTAB, TRITON X-100 and SDS) to retard the evaporation rate of SO 2 and DMS from water was estimated by the decrease of the k c values in the presence of the three surfactants, compared to those in the absence of surfactants. The more efficient surfactant for the retardation evaporation of SO 2 from both the pure and the artificial sea water was found to be the cationic CTAB surfactant, as the maximum decreases of the k c values were found to be 4.61×10 -3 cms -1 (number of films, n=1) and 3.07×10 -3 cms -1 (n=3), respectively. On the other hand, more efficient surfactant for the retardation evaporation of DMS from pure water was found to be the non-ionic TRITON X-100, in which the decrease of the k c value was estimated to be 18.20×10 -3 cms -1 (n=3) and from artificial sea water the cationic CTAB surfactant in which the decrease of the k c value was found to be 8.24×10 -3 cms -1 (n=3). Finally, the precision of the R.F.G.C. method in studying the retardation effect of various surfactants in the transfer of SO 2 and DMS from the water body to the atmosphere is estimated (mean value 96.69%), and the experimental values of k c are compared with those given in the literature. Copyright © 2016 Elsevier B.V. All rights reserved.

T1alpha/podoplanin shows raft-associated distribution in mouse lung alveolar epithelial E10 cells.

PubMed

Barth, Kathrin; Bläsche, Robert; Kasper, Michael

2010-01-01

T1alpha/(podoplanin) is abundantly expressed in the alveolar epithelial type I cells (ATI) of rodent and human lungs. Caveolin-1 is a classical primary structural protein of plasmalemal invaginations, so-called caveolae, which represent specialized lipid rafts, and which are particularly abundant in ATI cells. The biological functions of T1alpha in the alveolar epithelium are unknown. Here we report on the characteristics of raft domains in the microplicae/microvillar protrusions of ATI cells, which contain T1alpha. Detergent resistant membranes (DRMs) from cell lysates of the mouse epithelial ATI-like cell line E10 were prepared using different detergents followed by flotation in a sucrose gradient and tested by Western and dot blots with raft markers (caveolin-1, GM1) and nonraft markers (transferrin receptor, PDI and beta-Cop). Immunocytochemistry was employed for the localization of T1alpha in E10 cells and in situ in rat lungs. Our biochemical results showed that the solubility or insolubility of T1alpha and caveolin-1 differs in Triton X-100 and Lubrol WX, two distinct non-ionic detergents. Caveolin-1 was unsoluble in both detergents, whereas T1alpha was Triton X-100 soluble but Lubrol WX insoluble. Immunofluorescence double stainings revealed that both proteins were colocalized with GM1, while caveolin-1 and T1alpha were not colocalized in the plasma membrane. Cholesterol depletion modified the segregation of T1alpha in Lubrol WX DRMs. Cellular processes in ultrathin sections of cultured mouse E10 cells were immunogold positive. Immunoelectron microscopy (postembedding) of rat lung tissue revealed the preferential localization of T1alpha on apical microvillar protrusions of ATI cells. We conclude that T1alpha and caveolin-1 are located in distinct plasma membrane microdomains, which differ in their protein-lipid interactions. The raft-associated distribution of T1alpha may have an impact on a specific, not yet clarified function of this protein in the alveolar epithelium. 2010 S. Karger AG, Basel

Controlling the electrophoretic mobility of single-walled carbon nanotubes: a comparison of theory and experiment.

PubMed

Usrey, Monica L; Nair, Nitish; Agnew, Daniel E; Pina, Cesar F; Strano, Michael S

2007-07-03

The electrophoretic mobilities of single-walled carbon nanotubes (SWNTs) in agarose gels subjected to negatively charged covalent functionalization and noncovalent anionic surfactant adsorption are compared using a simplified hydrodynamic model. Net charges are calculated on the basis of estimated friction coefficients for cylindrical rodlike particles. The effects of functionalization with negatively charged 4-hydroxybenzene diazonium and anionic sodium cholate are quantified and compared with model predictions. The adsorption of Na+ counterions into the nonionic surfactant layer adsorbed on SWNTs (Triton-X-405) is shown to induce a positive charge and reverse the mobility under select conditions. This effect has not been identified or quantified for nanoparticle systems and may be important in the processing of these systems.

Formation of diacylglycerol by a phospholipase D-phosphatidate phosphatase pathway specific for phosphatidylcholine in endothelial cells.

PubMed

Martin, T W

1988-10-14

The conversion of phosphatidylcholine (PC) to diacylglycerol (DAG) was studied in sonicated endothelial cells and in subcellular fractions in the presence of 0.05% Triton X-100 and 2 mM EDTA. DAG formation occurred predominantly in an organelle fraction that sedimented at 15,000 x g. In parallel reactions with exogenous 1-oleoyl-2-[3H]oleoyl-PC (sn-2-[3H]DOPC) and phosphatidyl[3H]choline ([choline-3H]PC), [3H]DAG was formed by a reaction pathway in which [3H]choline was the only product derived from [choline-3H]PC. [3H]Choline was not formed secondarily from [3H]glycerophosphocholine or [3H]phosphocholine. Small amounts of [3H]phosphatidate ([3H]PA) were isolated from reactions with sn-2-[3H]DOPC at short incubation times, and substantial PA phosphatase activity was demonstrated. These data, taken together, supported a phospholipase D-PA phosphatase pathway of DAG formation. Kinetic data established that the low ratio of [3H]PA/[3H]DAG formed in reactions with sn-2-[3H]DOPC was due to a 15-fold higher Vmax and 7-fold lower apparent Km of the PA phosphatase. The [3H]PA/[3H]DAG product ratio was increased by addition of unlabeled PA or by selective extraction of phospholipase D with Triton X-100. The characteristics of the phospholipase D indicated a unique enzyme. Activity was optimal in the presence of EDTA and was almost totally dependent upon Triton X-100. The pH profile displayed a peak at 7.0. Of particular significance was the stringent substrate specificity. Phosphatidylinositol was not hydrolyzed, and activities towards phosphatidylethanolamine and sphingomyelin were at most 30- to 50-fold lower than those towards PC. Phospholipase D and PA phosphatase were identified in a number of rat tissues and other cells. The highest activities of phospholipase D were present in lung and endothelial cells. Phospholipase D was partially purified from rat lung by Triton X-100 extraction and anion exchange chromatography. When linked with PA phosphatase, the phospholipase D could initiate a pathway of DAG formation that is highly specific for PC.

Triton X-100 functionalized Fe3O4 nanoparticles for biomedical applications

NASA Astrophysics Data System (ADS)

Gawali, Santosh L.; Madan, Devendra P.; Barick, K. C.; Somani, R.; Hassan, P. A.

2018-04-01

We report the preparation of Triton X-100 functionalized Fe3O4 nanoparticles (TXMNPs) and investigated their potential application in hyperthermia therapy. The formation of highly crystalline, spinel-structured Fe3O4 nanoparticles of average size of about 10 nm was evident from X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses. Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), UV-visible spectroscopy and zeta-potential measurements suggest the successful functionalization of nanoparticles with TX-100. These TXMNPs exhibit good colloidal stabilization in aqueous medium and show protein resistance characteristic in physiological medium. They showed excellent heating efficacy under AC magnetic field (AMF) with specific absorption rate (SAR) values of 146 and 260 W/g of Fe for 1.25 and 0.625 mg/ml of Fe, respectively at an applied AMF of 507 Oe and frequency of 300 kHz. Thus, these nanoparticles can be used as effective thermoseed for hyperthermia treatment of cancer.

Biodegradation and surfactant-mediated biodegradation of diesel fuel by 218 microbial consortia are not correlated to cell surface hydrophobicity.

PubMed

Owsianiak, Mikołaj; Szulc, Alicja; Chrzanowski, Łukasz; Cyplik, Paweł; Bogacki, Mariusz; Olejnik-Schmidt, Agnieszka K; Heipieper, Hermann J

2009-09-01

In this study, we elucidated the role of cell surface hydrophobicity (microbial adhesion to hydrocarbons method, MATH) and the effect of anionic rhamnolipids and nonionic Triton X-100 surfactants on biodegradation of diesel fuel employing 218 microbial consortia isolated from petroleum-contaminated soils. Applied enrichment procedure with floating diesel fuel as a sole carbon source in liquid cultures resulted in consortia of varying biodegradation potential and diametrically different cell surface properties, suggesting that cell surface hydrophobicity is a conserved parameter. Surprisingly, no correlations between cell surface hydrophobicity and biodegradation of diesel fuel were found. Nevertheless, both surfactants altered cell surface hydrophobicity of the consortia in similar manner: increased for the hydrophilic and decreased for the hydrophobic cultures. In addition to this, the surfactants exhibited similar influence on diesel fuel biodegradation: Increase was observed for initially slow-degrading cultures and the opposite for fast degraders. This indicates that in the surfactant-mediated biodegradation, effectiveness of surfactants depends on the specification of microorganisms and not on the type of surfactant. In contrary to what was previously reported for pure strains, cell surface hydrophobicity, as determined by MATH, is not a good descriptor of biodegrading potential for mixed cultures.

The use of specific antibodies to mediate fusion between Sendai virus envelopes and living cells.

PubMed

Loyter, A; Tomasi, M; Gitman, A G; Etinger, L; Nussbaum, O

1984-01-01

Incubation of Sendai virus particles with non-ionic detergents such as Triton X-100 completely solubilizes the viral envelopes. Removal of the detergent from the supernatant (which contains the two main viral glycoproteins) leads to the formation of fusogenic, reconstituted viral envelopes. Soluble macromolecules such as DNA or proteins can be enclosed within the reconstituted vesicles, while membrane components can be inserted into the viral envelopes. Fusion of such loaded or 'hybrid' reconstituted envelopes with living cells in culture results in either microinjection or transfer of the viral components to the recipient cells. Thus such reconstituted envelopes can serve as efficient carriers for the introduction of macromolecules of biological interest into living cells in culture. A more specific vehicle has been constructed by chemically coupling anti-cell membrane antibodies (anti-human erythrocyte antibody) to the viral envelope. Such antibody-bearing intact virus particles or reconstituted envelopes bound to and fused with virus receptor-depleted cells. In addition, anti-Sendai virus antibodies were coupled to neuraminidase-treated human erythrocytes. Such antibodies mediated the binding and fusion of intact Sendai virus particles and their reconstituted envelopes to virus receptor-depleted cells.

Cholesterol depletion modulates detergent resistant fraction of human serotonin(1A) receptors.

PubMed

Sahu, Santosh Kumar; Saxena, Roopali; Chattopadhyay, Amitabha

2012-11-01

Insolubility of membrane components in non-ionic detergents such as Triton X-100 at low temperature is a widely used biochemical criterion to identify, isolate and characterize membrane domains. In this work, we monitored the detergent insolubility of the serotonin(1A) receptor in CHO cell membranes and its modulation by membrane cholesterol. The serotonin(1A) receptor is an important member of the G-protein coupled receptor family. It is implicated in the generation and modulation of various cognitive, behavioral and developmental functions and serves as a drug target. Our results show that a significant fraction (∼28%) of the serotonin(1A) receptor resides in detergent-resistant membranes (DRMs). Interestingly, the fraction of the serotonin(1A) receptor in DRMs exhibits a reduction upon membrane cholesterol depletion. In addition, we show that contents of DRM markers such as flotillin-1, caveolin-1 and GM₁ are altered in DRMs upon cholesterol depletion. These results assume significance since the function of the serotonin(1A) receptor has previously been shown to be affected by membrane lipids, specifically cholesterol. Our results are relevant in the context of membrane organization of the serotonin(1A) receptor in particular, and G-protein coupled receptors in general.

Synthesis of colloidal metal nanocrystals in droplet reactors: the pros and cons of interfacial adsorption.

PubMed

Zhang, Lei; Wang, Yi; Tong, Limin; Xia, Younan

2014-07-09

Droplet reactors have received considerable attention in recent years as an alternative route to the synthesis and potentially high-volume production of colloidal metal nanocrystals. Interfacial adsorption will immediately become an important issue to address when one seeks to translate a nanocrystal synthesis from batch reactors to droplet reactors due to the involvement of higher surface-to-volume ratios for the droplets and the fact that nanocrystals tend to be concentrated at the water-oil interface. Here we report a systematic study to compare the pros and cons of interfacial adsorption of metal nanocrystals during their synthesis in droplet reactors. On the one hand, interfacial adsorption can be used to generate nanocrystals with asymmetric shapes or structures, including one-sixth-truncated Ag octahedra and Au-Ag nanocups. On the other hand, interfacial adsorption has to be mitigated to obtain nanocrystals with uniform sizes and controlled shapes. We confirmed that Triton X-100, a nonionic surfactant, could effectively alleviate interfacial adsorption while imposing no impact on the capping agent typically needed for a shape-controlled synthesis. With the introduction of a proper surfactant, droplet reactors offer an attractive platform for the continuous production of colloidal metal nanocrystals.

Production of citrinin-free Monascus pigments by submerged culture at low pH.

PubMed

Kang, Biyu; Zhang, Xuehong; Wu, Zhenqiang; Wang, Zhilong; Park, Sunghoon

2014-02-05

Microbial fermentation of citrinin-free Monascus pigments is of great interest to meet the demand of food safety. In the present work, the effect of various nitrogen sources, such as monosodium glutamate (MSG), cornmeal, (NH4)₂SO₄, and NaNO₃, on Monascus fermentation was examined under different initial pH conditions. The composition of Monascus pigments and the final pH of fermentation broth after Monascus fermentation were determined. It was found that nitrogen source was directly related to the final pH and the final pH regulated the composition of Monascus pigments and the biosynthesis of citrinin. Thus, an ideal nitrogen source can be selected to control the final pH and then the citrinin biosynthesis. Citrinin-free orange pigments were produced at extremely low initial pH in the medium with (NH4)₂SO₄ or MSG as nitrogen source. No citrinin biosynthesis at extremely low pH was further confirmed by extractive fermentation of intracellular pigments in the nonionic surfactant Triton X-100 micelle aqueous solution. This is the first report about the production of citrinin-free Monascus pigments at extremely low pH. Copyright © 2013 Elsevier Inc. All rights reserved.

Simultaneous injection effective mixing flow analysis of urinary albumin using dye-binding reaction.

PubMed

Ratanawimarnwong, Nuanlaor; Ponhong, Kraingkrai; Teshima, Norio; Nacapricha, Duangjai; Grudpan, Kate; Sakai, Tadao; Motomizu, Shoji

2012-07-15

A new four-channel simultaneous injection effective mixing flow analysis (SIEMA) system has been assembled for the determination of urinary albumin. The SIEMA system consisted of a syringe pump, two 5-way cross connectors, four holding coils, five 3-way solenoid valves, a 50-cm long mixing coil and a spectrophotometer. Tetrabromophenol blue anion (TBPB) in Triton X-100 micelle reacted with albumin at pH 3.2 to form a blue ion complex with a λ(max) 625nm. TBPB, Triton X-100, acetate buffer and albumin standard solutions were aspirated into four individual holding coils by a syringe pump and then the aspirated zones were simultaneously pushed in the reverse direction to the detector flow cell. Baseline drift, due to adsorption of TBPB-albumin complex on the wall of the hydrophobic PTFE tubing, was minimized by aspiration of Triton X-100 and acetate buffer solutions between samples. The calibration graph was linear in the range of 10-50μg/mL and the detection limit for albumin (3σ) was 0.53μg/mL. The RSD (n=11) at 30μg/mL was 1.35%. The sample throughput was 37/h. With a 10-fold dilution, interference from urine matrix was removed. The proposed method has advantages in terms of simple automation operation and short analysis time. Copyright © 2012 Elsevier B.V. All rights reserved.

Differential antigenic protein recovery from Taenia solium cyst tissues using several detergents.

PubMed

Navarrete-Perea, José; Orozco-Ramírez, Rodrigo; Moguel, Bárbara; Sciutto, Edda; Bobes, Raúl J; Laclette, Juan P

2015-07-01

Human and porcine cysticercosis is caused by the larval stage of the flatworm Taenia solium (Cestoda). The protein extracts of T. solium cysts are complex mixtures including cyst's and host proteins. Little is known about the influence of using different detergents in the efficiency of solubilization-extraction of these proteins, including relevant antigens. Here, we describe the use of CHAPS, ASB-14 and Triton X-100, alone or in combination in the extraction buffers, as a strategy to notably increase the recovery of proteins that are usually left aside in insoluble fractions of cysts. Using buffer with CHAPS alone, 315 protein spots were detected through 2D-PAGE. A total of 255 and 258 spots were detected using buffers with Triton X-100 or ASB-14, respectively. More protein spots were detected when detergents were combined, i.e., 2% CHAPS, 1% Triton X-100 and 1% ASB-14 allowed detection of up to 368 spots. Our results indicated that insoluble fractions of T. solium cysts were rich in antigens, including several glycoproteins that were sensitive to metaperiodate treatment. Host proteins, a common component in protein extracts of cysts, were present in larger amounts in soluble than insoluble fractions of cysts proteins. Finally, antigens present in the insoluble fraction were more appropriate as a source of antigens for diagnostic procedures. Copyright © 2015 Elsevier B.V. All rights reserved.

Specificity of diffusion channels produced by lambda phage receptor protein of Escherichia coli.

PubMed Central

Luckey, M; Nikaido, H

1980-01-01

The lamB protein, the receptor for phage lambda, was purified from the outer membrane of Escherichia coli K-12 by extraction with Triton X-100 and EDTA, chromatography on DEAE-Sephacel in Triton X-100, exchange of Triton for cholate by gel filtration, and chromatography on Sephacryl S-200 in cholate, NaCl, and EDTA. The purified protein appeared to exist as several oligomeric species. In an equilibrium retention assay with reconstituted vesicles containing phospholipids and lipopolysaccharide, the lamB protein conferred permeability for disaccharides. In a liposome swelling assay designed to measure rates of diffusion, the lamB protein conferred permeability to phospholipid liposomes for a variety of substrates. The rates obtained indicate the permeation facilitated by the lamB protein is specific, discriminating among substrates by both size and configuration. For example, maltose diffused into liposomes 40 times faster than sucrose, about 8 times faster than cellobiose, and about 12 times faster than maltoheptaose. The results suggest that the lamB protein forms a transmembrane channel containing a site (or sites) that loosely interacts with the solutes. Images PMID:6444720

Erythrocyte hemolysis by detergents.

PubMed

Chernitsky, E A; Senkovich, O A

1997-01-01

The numbers of Triton X-100 and sodium dodecyl sulfate molecules required to form respective pores were estimated from the relationship between the detergent concentrations and the rates of fast and slow hemolysis components. It has been found that the slow hemolysis component evoked by Triton X-100 is related to the existence of two different pores. It is shown that the fast hemolysis component induced by sodium dodecyl sulfate is associated with the modification of phosphatidylcholine which determines the break in the Arrhenius plots of the hemolysis rate within the range of 20 degrees C. The shape of hemolysis kinetic curves and the dependence of hemolytic parameters on the detergent concentration and temperature are discussed based on the concept of hemolysis caused by the formation of pores in various membrane lipid regions and by releasing vesicles from erythrocytes.

Stability of thermostable alkaline protease from Bacillus licheniformis RP1 in commercial solid laundry detergent formulations.

PubMed

Sellami-Kamoun, Alya; Haddar, Anissa; Ali, Nedra El-Hadj; Ghorbel-Frikha, Basma; Kanoun, Safia; Nasri, Moncef

2008-01-01

The stability of crude extracellular protease produced by Bacillus licheniformis RP1, isolated from polluted water, in various solid laundry detergents was investigated. The enzyme had an optimum pH and temperature at pH 10.0-11.0 and 65-70 degrees C. Enzyme activity was inhibited by PMSF, suggesting that the preparation contains a serine-protease. The alkaline protease showed extreme stability towards non-ionic (5% Tween 20% and 5% Triton X-100) and anionic (0.5% SDS) surfactants, which retained 100% and above 73%, respectively, of its initial activity after preincubation 60 min at 40 degrees C. The RP1 protease showed excellent stability and compatibility with a wide range of commercial solid detergents at temperatures from 40 to 50 degrees C, suggesting its further application in detergent industry. The enzyme retained 95% of its initial activity with Ariel followed by Axion (94%) then Dixan (93.5%) after preincubation 60 min at 40 degrees C in the presence of 7 mg/ml of detergents. In the presence of Nadhif and New Det, the enzyme retained about 83.5% of the original activity. The effects of additives such as maltodextrin, sucrose and PEG 4000 on the stability of the enzyme during spray-drying and during subsequent storage in New Det detergent were also examined. All additives tested enhanced stability of the enzyme.

Biodegradation of a keratin waste and the concomitant production of detergent stable serine proteases from Paecilomyces lilacinus.

PubMed

Cavello, I A; Cavalitto, S F; Hours, R A

2012-07-01

Paecilomyces lilacinus (LPS 876) efficiently degraded keratin in chicken feather during submerged cultivation producing extracellular proteases. Characterization of crude protease activity was done including its compatibility in commercial detergents. Optimum pH and temperature were 10.0 and 60 °C, respectively. Protease activity was enhanced by Ca²⁺ but was strongly inhibited by PMSF and by Hg²⁺ suggesting the presence of thiol-dependent serine proteases. The crude protease showed extreme stability toward non-ionic (Tween 20, Tween 85, and Triton X-100) and anionic (SDS) surfactants, and relative stability toward oxidizing agent (H₂O₂ and sodium perborate). In addition, it showed excellent stability and compatibility with various solid and liquid commercial detergents from 30 to 50 °C. The enzyme preparation retained more than 95% of its initial activity with solid detergents (Ariel™ and Drive™) and 97% of its original activity with a liquid detergent (Ace™) after pre-incubation at 40 °C. The protective effect of polyols (propylene glycol, PEG 4000, and glycerol) on the heat inactivation was also examined and the best results were obtained with glycerol from 50 to 60 °C. Considering its promising properties, P. lilacinus enzymatic preparation may be considered as a candidate for use in biotechnological processes (i.e., as detergent additive) and in the processing of keratinous wastes.

Structure and reactions in some amphiphilic association systems

NASA Astrophysics Data System (ADS)

Guo, Rong

1999-06-01

The partial determinations of phase diagrams for some typical surfactants, such as SDS, CTAB and Triton X-100, give the basic aggregated states of the surfactant systems. In the micellar solutions, the diffusion coefficients of some surfactant association systems are determined by the cyclic voltammetry without any probe and used to describe the phase structure. (1) The first CMC, which represents the formation of spherical micelles, and the second CMC, which represents the transformation from spherical to rod-like micelles, are measured. The first and the second CMC are 8.0 x 10-3 mol. L -1 and 5.6 x 10-3 mol. L-1 for SDS, 8.9 x 10-4 mol. L-1 and 2.1 x 10-2 mol. L-1 for CTAB, and 3.2 x 10 -4 mol. L-1 and 1.3 x 10-3 mol. L-1 for Triton X-100, respectively. (2) The addition of polar additives, such as ethanol and benzyl alcohol (BA) in SDS micelles, or hexanol in Triton X-100 micelles, increases the diffusion coefficients and diffusion activation energy, decreases the micropolarity of the micelles with different shape, and causes the transformation from rod-like micelles to spherical ones or from spherical micelles to bicontinuous structure. (3) The isotropic region, which connects to the water comer in the phase diagram, is probably not an area of a single O/W structure, but an area with three different structures---the rod structure, spherical structure and the bicontinuous one. In the lyotropic liquid crystalline phase, the measurements of the small angle X-ray diffraction indicate that the structure parameters, such as interlayer spacing and water penetration, are related to the compositions of the surfactant association systems. The lamellar liquid crystal has a high water penetration but the hexagonal liquid crystal only has a water penetration about 0.05. Some surfactant association systems have been applied in the hydrotrope action of vitamin C (VC) and preparation of nanoparticles, respectively. Vitamin C (VC) can be used as hydrotrope agent in the cationic surfactant CTAB system with various co-surfactants: n-pentanol, n-octanol, n-valeric acid, and n-caproic acid, but not in SDS or Triton X-100 systems. Presence of VC stabilizes both W/O and O/W microemulsions but destabilizes the lamellar liquid crystalline phase. Hence, the "phase transition" from the lamellar liquid crystalline phase to the isotropic phase of O/W, W/O and bicontinuous structure phase occurs with the addition of VC. The hydrotropic action of VC has been used in sunscreens to increase the solubility of sunscreen E 557. The UV absorption spectra of E557 in various media surprisingly had a dependence on the colloid structure. A new method, the preparation of water-soluble nanoparticles, has been found by employing the effect of the penetration of solvent from water layer to amphiphilic layer in lamellar liquid crystals on the solubility of inorganic salts. Water-insoluble nanoparticles have been synthesized by the reaction of two water-soluble inorganic salts in the lamellar liquid crystal. The particle size is less than 10nm and can be controlled by the thickness of the solvent layer in the lamellar liquid crystal. The lamellar liquid crystalline phase of the Triton X-100/decanol/water system has been chosen as a medium because of its large lamellar liquid crystal region and its stability when inorganic salts are added.

Determination of ultra-trace aluminum in human albumin by cloud point extraction and graphite furnace atomic absorption spectrometry.

PubMed

Sun, Mei; Wu, Qianghua

2010-04-15

A cloud point extraction (CPE) method for the preconcentration of ultra-trace aluminum in human albumin prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. The CPE method was based on the complex of Al(III) with 1-(2-pyridylazo)-2-naphthol (PAN) and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 34.8 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of Al(III) was 0.06 ng mL(-1). The relative standard deviation (n=7) of sample was 3.6%, values of recovery of aluminum were changed from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination of ultra-trace aluminum in human albumin. 2009 Elsevier B.V. All rights reserved.

Starbursts and Wispy Drops : Surfactants Spreading on Gel Substrates

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Shomeek; Daniels, Karen; Behringer, Robert

2005-11-01

We report a phase diagram for a novel instability seen in drops of nonionic surfactant solution (Triton X-305) spreading on viscoelastic agar gel substrate . This system allows us to examine the effect of varying the effective fluidity/stiffness of aqueous substrates. The morphology is strongly affected by the substrate fluidity, ranging from spreading starbursts of arms on weak gels, to wispy drops on intermediate strength gels, to circular drops on stiff gels. We analyze the dynamics of spreading in the starburst phase, where the arm length grows as t ^3/4 at early times, independent of the gel strength and surfactant concentration. The number of arms is proportional to the surfactant concentration and inversely proportional to the gel strength. Ongoing work is exploring the effects of changing the drop volume.

FOR STIMUL-RESPONSIVE POLYMERS WITH ENHANCED EFFICIENCY IN RESERVOIR RECOVERY PROCESSES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charles McCormick; Roger Hester

This report contains a series of terpolymers containing acrylic acid, methacrylamide and a twin-tailed hydrophobic monomer that were synthesized using micellar polymerization methods. These polymer systems were characterized using light scattering, viscometry, and fluorescence methods. Viscosity studies indicate that increasing the nonpolar character of the hydrophobic monomer (longer chain length or twin tailed vs. single tailed) results in enhanced viscosity in aqueous solutions. The interactions of these polymers with surfactants were investigated. These surfactants include sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB), Triton X-100. Viscosity measurements of DiC{sub 6}AM and DiC{sub 8}AM mixtures indicate little interaction with SDS,more » gelation with CTAB, and hemimicelle formation followed by polymer hydrophobe solubilization with Triton X-100. The DiC{sub 10}Am terpolymer shows similar interaction behavior with CTAB and Triton X-100. However, the enhanced hydrophobic nature of the DiC{sub 10} polymer allows complex formation with SDS as confirmed by surface tensiometry. Fluorescence measurements performed on a dansyl labeled DiC{sub 10}Am terpolymer in the presence of increasing amounts of each of the surfactant indicate relative interaction strengths to be CTAB>Triton X-100>SDS. A modified model based on Yamakawa-Fujii and Odjik-Skolnick-Fixman theories was found to describe the contribution of electrostatic forces to the excluded volume of a polyelectrolyte in solution. The model was found to be valid for flexible polymer coils in aqueous salt solutions where intermolecular interactions are minimal. The model suggested that a dimensionless group of parameters termed the dimensionless viscosity should be proportional to the dimensionless ratio of solution screening length to polyion charge spacing. Several sets of experimental data from the literature and from our laboratory have been analyzed according to the model and the results suggest that the two dimensionless groups are indeed related by a universal constant. This model has identified the parameters that are important to fluid mobility, thereby revealing methods to enhance solution performance when using polyions solutions as displacing fluids in oil reservoirs.« less

Hydrodynamic properties of the gonadotropin receptor from a murine Leydig tumor cell line are altered by desensitization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rebois, R.V.; Bradley, R.M.; Titlow, C.C.

1987-10-06

The murine Leydig tumor cell line 1 (MLTC-1) contains gonadotropin receptors (GR) that are coupled to adenylate cyclase through the stimulatory guanine nucleotide binding protein (G/sub s/). The binding of human choriogonadotropin (hGC) causes MLTC-1 cells to accumulate cAMP. With time, the ability of MLTC-1 cells to respond to hCG is attenuated by a process called desensitization. The hydrodynamic properties of GR from control and desensitized MLTC-1 cells were studied. Sucrose density gradient sedimentation in H/sub 2/O and D/sub 2/O and gel filtration chromatography were used to estimate the Stokes radius (a), partial specific volume (v/sub c/), sedimentation coefficient (s/submore » 20,w/), and molecular weight (M/sub r/) of the detergent-solubilized hormone-receptor complex (hCG-GR). (/sup 125/I)hCG was bound to MLTC-1 cells under conditions that allow (37/sup 0/C) or prevent (0/sup 0/C) desensitization, and hCG-GR was solubilized in Triton X-100. In the absence of desensitization, control hCG-GR had a M/sub r/ of 213,000, whereas desensitized hCG-GR had a M/sub r/ of 158,000. Deglycosylated hCG (DG-HCG) is an antagonist that binds to GR with high affinity but fails to stimulate adenylate cyclase or cause desensitization. (/sup 125/I)DG-hCG was bound to MLTC-1 cells and DG-hCG-GR solubilized in Triton X-100. The hydrodynamic properties of DG-hCG-GR were the same as that for control hCG-GR. There was no evidence for the association of adenylate cyclase or G/sub s/ with GR in Triton X-100 solubilized preparations. When hCG was cross-linked to GR and solubilized with sodium dodecyl sulfate (SDS), the M/sub r/ was found to be 116,000, which was similar to that determined by SDS-polyacrylamide gel electrophoresis and less than that of the Triton X-100 solubilized control hCG-GR.« less

Drug resistance-associated changes in sphingolipids and ABC transporters occur in different regions of membrane domains.

PubMed

Hinrichs, John W J; Klappe, Karin; van Riezen, Manon; Kok, Jan W

2005-11-01

We have recently shown that two ATP binding cassette (ABC) transporters are enriched in Lubrol-resistant noncaveolar membrane domains in multidrug-resistant human cancer cells [Hinrichs, J. W. J., K. Klappe, I. Hummel, and J. W. Kok. 2004. ATP-binding cassette transporters are enriched in non-caveolar detergent-insoluble glycosphingolipid-enriched membrane domains (DIGs) in human multidrug-resistant cancer cells. J. Biol. Chem. 279: 5734-5738]. Here, we show that aminophospholipids are relatively enriched in Lubrol-resistant membrane domains compared with Triton X-100-resistant membrane domains, whereas sphingolipids are relatively enriched in the latter. Moreover, Lubrol-resistant membrane domains contain more protein and lipid mass. Based on these results, we postulate a model for detergent-insoluble glycosphingolipid-enriched membrane domains consisting of a Lubrol-insoluble/Triton X-100-insoluble region and a Lubrol-insoluble/Triton X-100-soluble region. The latter region contains most of the ABC transporters as well as lipids known to be necessary for their efflux activity. Compared with drug-sensitive cells, the detergent-insoluble glycosphingolipid-enriched membrane domains (DIGs) in drug-resistant cells differ specifically in sphingolipid content and not in protein, phospholipid, or cholesterol content. In drug-resistant cells, sphingolipids with specific fatty acids (especially C24:1) are enriched in these membrane domains. Together, these data show that multidrug resistance-associated changes in both sphingolipids and ABC transporters occur in DIGs, but in different regions of these domains.

ABCA1, ABCG1, and ABCG4 are distributed to distinct membrane meso-domains and disturb detergent-resistant domains on the plasma membrane.

PubMed

Sano, Osamu; Ito, Shiho; Kato, Reiko; Shimizu, Yuji; Kobayashi, Aya; Kimura, Yasuhisa; Kioka, Noriyuki; Hanada, Kentaro; Ueda, Kazumitsu; Matsuo, Michinori

2014-01-01

ATP-binding cassette A1 (ABCA1), ABCG1, and ABCG4 are lipid transporters that mediate the efflux of cholesterol from cells. To analyze the characteristics of these lipid transporters, we examined and compared their distributions and lipid efflux activity on the plasma membrane. The efflux of cholesterol mediated by ABCA1 and ABCG1, but not ABCG4, was affected by a reduction of cellular sphingomyelin levels. Detergent solubility and gradient density ultracentrifugation assays indicated that ABCA1, ABCG1, and ABCG4 were distributed to domains that were solubilized by Triton X-100 and Brij 96, resistant to Triton X-100 and Brij 96, and solubilized by Triton X-100 but resistant to Brij 96, respectively. Furthermore, ABCG1, but not ABCG4, was colocalized with flotillin-1 on the plasma membrane. The amounts of cholesterol extracted by methyl-β-cyclodextrin were increased by ABCA1, ABCG1, or ABCG4, suggesting that cholesterol in non-raft domains was increased. Furthermore, ABCG1 and ABCG4 disturbed the localization of caveolin-1 to the detergent-resistant domains and the binding of cholera toxin subunit B to the plasma membrane. These results suggest that ABCA1, ABCG1, and ABCG4 are localized to distinct membrane meso-domains and disturb the meso-domain structures by reorganizing lipids on the plasma membrane; collectively, these observations may explain the different substrate profiles and lipid efflux roles of these transporters.

Hydrolysis of short-chain phosphatidylcholines by bee venom phospholipase A2.

PubMed

Raykova, D; Blagoev, B

1986-01-01

In order to find out the aggregation state of the substrate, preferred by bee venom phospholipase A2 (EC 3.1.1.4), its action on short-chain phosphatidylcholines with two identical (C6-C10) fatty acids has been tested. The rate of hydrolysis as a function of acyl chain length showed a maximum at dioctanoylphosphatidylcholine. The effects of alcohols, NaCl and Triton X-100, which affect the aggregation state of phospholipids in water, were also studied. The addition of n-alcohol led to a significant inhibition of the hydrolysis of the substrates present in micellar form and activated the hydrolysis of substrates which form liposomes. The inhibitory effect increased with increasing length of the aliphatic carbon chain of the alcohol. Triton X-100 at low Triton/phospholipid molar ratios enhanced enzyme activity. These results do not agree with the accepted idea that bee venom phospholipase A2 hydrolyzes short-chain lecithins in their molecularly dispersed form and that micelles cannot act as substrates. The data indicate that short-chain lecithins in the aggregated state are hydrolyzed and that the requirements of bee venom phospholipase A2 for the aggregation state of the substrate are not strict.

Enhancing enzymatic hydrolysis of coconut husk through Pseudomonas aeruginosa AP 029/GLVIIA rhamnolipid preparation.

PubMed

de Araújo, Cynthia Kérzia Costa; de Oliveira Campos, Alan; de Araújo Padilha, Carlos Eduardo; de Sousa Júnior, Francisco Canindé; do Nascimento, Ruthinéia Jéssica Alves; de Macedo, Gorete Ribeiro; Dos Santos, Everaldo Silvino

2017-08-01

This work investigated the influence of chemical (Triton X-100) and biological surfactant preparation (rhamnolipids) in coconut husk hydrolysis that was subjected to pretreatment with acid-alkali or alkaline hydrogen peroxide. The natural and pretreated biomass was characterized using the National Renewable Energy Laboratory protocol analysis as well as X-ray diffraction and scanning electron microscopy. The results demonstrated that in terms of the total reducing sugars, there was no significant difference between the hydrolysis using Triton X-100 and rhamnolipids, regardless of the pretreatment. A cellulosic conversion value as high as 33.0% was obtained in experiments with rhamnolipids. The coconut husk was observed to be a potential biomass that could produce second generation ethanol, and the rhamnolipid preparation can be used to support for the enzymatic hydrolysis, enhancing the advantage of cellulose conversion into glucose over chemical surfactants because it is an environmentally friendly approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Photooxidation of P700 in photosystem 1 preparations with various amounts of antenna chlorophyll a].

PubMed

Il'ina, M D; Borisov, A Iu

1982-12-01

A number of membrane fragments and pigment-protein complexes of photosystem 1 was obtained from pea chloroplasts, using ionic and non-ionic detergents (SDS, digitonin, Triton X-100, lauryldimethylamine-N-oxide). The ratio of chlorophyll (Chl) a to P700 varied from 220 to 30. For non-dialyzed preparations the quantum yield of P700 photooxidation (phi e) measured by the initial rate of photobleaching at 696-698 nm with excitation at the Soret band of Chla was equal to 40-60%. When the P700 photooxidation was measured at 432 nm, the phi e value showed a further decrease to 20-40% during red light excitation over the range of 660-680 nm but rose to 70-90% at the exciting light wavelengths of greater than or equal to 695 nm. On the basis of the observed dependences the red absorption band was approximated by a sum of two spectra: the spectrum of Chla photoactive in P700 photooxidation and that of photoinactive Chla. Both spectra had maxima near the absorption peak of the object. The photoinactive fraction was additionally enriched by the long-wavelength absorption forms of Chla with an absorption maximum over the range of 684-690 nm. The amount of the bulk Chla in the photoinactive fraction was no less than 40%. The phi e value for freshly dialyzed preparation at a Chla/P700 ratio of 30 was equal to 50-60% independent of the exciting light wavelength. An addition of 0.05% Triton X-100 to this preparation caused: i) a blue shift of the absorption and fluorescence maxima; ii) a decrease of the long-wavelength absorption forms content of Chla and, iii) a considerable increase in fluorescence lifetime and quantum yield due to deaggregation of Chla and its solubilization by detergent micelles. The same phenomenon seems to be responsible for the formation of photoinactive fraction of a pigment, since after addition of a detergent the above-mentioned spectral dependence of phi e appeared, i.e. phi e showed a 3-fold decrease (down to 18%) within the region of 660-680 nm and a 1,6-fold increase (up to 90%) at 705-730 nm. These results suggest that the detergents destroy the intact construction of a light-harvesting antenna rather than that of the photosystem 1 reaction center.

The size of adenylate cyclase and guanylate cyclase from the rat renal medulla.

PubMed

Neer, E J

1976-01-01

The size distribution of adenylate cyclase from the rat renal medulla solubilized with the nonionic detergents Triton X-100 and Lubrol PX was determined by gel filtration and by centrifugation in sucrose density gradients made up in H2O or D2O. The physical parameters of the predominant form in Triton X-100 are s20,w, 5.9S; Strokes radius, 62 A; partial specific volume (v), 0.74 ml/g; mass, 159,000 daltons; f/f0, 1.6; axial ratio (prolate ellipsoid), 11. For the minor form the values are: s20w, 3.0; Stokes radius, 28 A; mass, 38,000 daltons; f/f0, 1.2. The corresponding values determined in Lubrol PX are similar. The value for V for the enzyme indicates that it binds less than 0.2 mg detergent/mg protein. Since interactions with detergents probably substitute for interactions with lipids and hydrophobic amino acid side chains, these findings suggest that no more than 5% of the surface of adenylate cyclase is involved in hydrophobic interactions with other membrane components. Thus, most of the mass of the enzyme is not deeply embedded in the lipid bilayer of the plasma membrane. Similar studies have been performed on the soluble guanylate cyclase of the rat renal medulla. In the absence of detergent, the molecular properties of this enzyme are: s20w, 6.3S; Stokes radius, 54 A, V, 0.75 ml/g; mass, 154,000 daltons f/f0, 1.4; Axial ratio, 7. The addition of 0.1% Lubrol PX to this soluble enzyme increases it activity two- to fourfold and changes the physical properties to: s20,w, 5.5S; Stokes radius, 62 A; V, 0.74 ml/g; mass, 148,000 daltons, f/f0, 1.6; axial ratio, 11. These results show that Lubrol PX activates the enzyme by causing a conformational change with unfolding on the polypeptide chain. Guanylate cyclase from the particulate cell fraction can be solubilized with Lubrol PX but has properties quite different from those of the enzyme in the soluble cell fraction. It is a heterogeneous aggregate with s20,w, 10S; Stokes radius, 65 A; mass about 300,000 daltons. The conditions which solubilize guanylate cyclase also solubilize adenylate cyclase and the two activities can be separated on the same sucrose gradient.

Apo AI/ABCA1-dependent and HDL3-mediated lipid efflux from compositionally distinct cholesterol-based microdomains.

PubMed

Drobnik, Wolfgang; Borsukova, Hana; Böttcher, Alfred; Pfeiffer, Alexandra; Liebisch, Gerhard; Schütz, Gerhard J; Schindler, Hansgeorg; Schmitz, Gerd

2002-04-01

We have investigated whether a raft heterogeneity exists in human monocyte-derived macrophages and fibroblasts and whether these microdomains are modulated by lipid efflux. Triton X-100 (Triton) or Lubrol WX (Lubrol) detergent-resistant membranes from cholesterol-loaded monocytes were associated with the following findings: (i) Lubrol-DRM contained most of the cellular cholesterol and at least 75% of Triton-detergent-resistant membranes. (ii) 'Lubrol rafts', defined by their solubility in Triton but insolubility in Lubrol, were enriched in unsaturated phosphatidylcholine and showed a lower cholesterol to choline-phospholipid ratio compared to Triton rafts. (iii) CD14 and CD55 were recovered in Triton- and Lubrol-detergent-resistant membranes, whereas CD11b was found exclusively in Triton DRM. ABCA1 implicated in apo AI-mediated lipid efflux and CDC42 were partially localized in Lubrol- but not in Triton-detergent-resistant membranes. (iv) Apo AI preferentially depleted cholesterol and choline-phospholipids from Lubrol rafts, whereas HDL3 additionally decreased the cholesterol content of Triton rafts. In fibroblasts, neither ABCA1 nor CDC42 was found in Lubrol rafts, and both apo AI and HDL3 reduced the lipid content in Lubrol- as well as in Triton-detergent-resistant membranes. In summary, we provide evidence for the existence of compositionally distinct membrane microdomains in human cells and their modulation by apo AI/ABCA1-dependent and HDL3-mediated lipid efflux.

Rat lingual lipase: partial purification, hydrolytic properties, and comparison with pancreatic lipase.

PubMed

Roberts, I M; Montgomery, R K; Carey, M C

1984-10-01

We have partially purified lingual lipase from the serous glands of rat tongue. With a combination of Triton X-100 extraction or Triton X-114 phase-separation techniques, Bio-Bead SM-2 treatment, dialysis, and gel filtration on Sephadex G-200 or Sephacryl S-300, we obtained a sparingly soluble lipid-free protein demonstrating hydrolytic activity against triglycerides and negligible phospholipase or cholesteryl esterase activities. Compared with homogenate, specific activities of the enzyme were enriched 3- to 5-fold prior to gel filtration and 10-fold after gel filtration. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration under denaturing conditions (6 M guanidine X HCl or 0.1% sodium dodecyl sulfate) revealed one major glycoprotein band with Mr approximately 50,000. Gel filtration of the active enzyme in 0.1% Triton X-100 gave an Mr approximately 270,000-300,000, suggesting extensive self-aggregation. With both tributyrin and triolein, the pH optimum of the purified enzyme was 4.0 and activity extended from pH 2.0 to 8.0. In contrast to purified human pancreatic lipase, lingual lipase hydrolyzed triglyceride emulsions and mixed micelles stabilized with both short-chain (dihexanoyl) and long-chain (egg) lecithin and were inhibited only slightly (18-25%) by micellar concentrations of two common bile salts, taurodeoxycholate and taurocholate. Our results suggest that the hydrolysis of dietary fat by lingual lipase may extend from the pharynx through the esophagus and stomach and into the upper small intestine.

Triton X-100 as an effective surfactant for the isolation and purification of photosystem I from Arthrospira platensis.

PubMed

Yu, Daoyong; Huang, Guihong; Xu, Fengxi; Wang, Mengfei; Liu, Shuang; Huang, Fang

2014-06-01

Surfactants play important roles in the preparation, structural, and functional research of membrane proteins, and solubilizing and isolating membrane protein, while keeping their structural integrity and activity intact is complicated. The commercial n-Dodecyl-β-D-maltoside (DDM) and Triton X-100 (TX) were used as solubilizers to extract and purify trimeric photosystem I (PSI) complex, an important photosynthetic membrane protein complex attracting broad interests. With an optimized procedure, TX can be used as an effective surfactant to isolate and purify PSI, as a replace of the much more expensive DDM. A mechanism was proposed to interpret the solubilization process at surfactant concentrations lower than the critical solubilization concentration. PSI-TX and PSI-DDM had identical polypeptide bands, pigment compositions, oxygen consumption, and photocurrent activities. This provides an alternative procedure and paves a way for economical and large-scale trimeric PSI preparation.

Obtaining Soluble Folded Proteins from Inclusion Bodies Using Sarkosyl, Triton X-100, and CHAPS: Application to LB and M9 Minimal Media.

PubMed

Massiah, Michael A; Wright, Katharine M; Du, Haijuan

2016-04-01

This unit describes a straightforward and efficient method of using sarkosyl to solubilize and recover difficult recombinant proteins, such as GST- and His6 -tagged fusion proteins, that are overexpressed in E. coli. This protocol is especially useful for rescuing recombinant proteins overexpressed in M9 minimal medium. Sarkosyl added to lysis buffers helps with both protein solubility and cell lysis. Higher percentage sarkosyl (up to 10%) can extract >95% of soluble protein from inclusion bodies. In the case of sarkosyl-solubilized GST-fusion proteins, batch-mode affinity purification requires addition of a specific ratio of Triton X-100 and CHAPS, while sarkosyl-solubilized His6 -tagged fusion proteins can be directly purified on Ni(2+) resin columns. Proteins purified by this method could be widely used in biological assays, structure analysis and mass spectrum assay. Copyright © 2016 John Wiley & Sons, Inc.

Identification and partial characterization of a bacteriocin-like inhibitory substance (BLIS) from Lb. Bulgaricus K41 isolated from indigenous yogurts.

PubMed

Zaeim, Davood; Soleimanian-Zad, Sabihe; Sheikh-Zeinoddin, Mahmoud

2014-01-01

Forty-two strains of Lactobacillus bulgaricus isolated from locally made yogurts were examined and compared for bacteriocin producing ability using spot on lawn assay which improved by taking photo and image processing. Lb. bulgaricus K41 exhibited the highest inhibition level against indicators. K41 Bacteriocin-like inhibitory substance is sensitive to proteolytic enzymes (proteinase K, pepsin, and trypsin) but α-amylase makes slight reduction in its activity and it is resistant to lipase. This antibacterial peptide is extremely heat-stable (121 °C for 15 min) and remains active over a wide pH range (pH = 2 to 10); also nonionic detergents (Tween-20, Tween-80, and Triton X100) showed no effect on its activity. The inhibitory spectrum is against Gram-positive bacteria (except Staphylococcus aureus) with extremely antilisterial activity and it is almost ineffective against Gram-negative bacteria. The mode of its action was identified as bactericidal against Listeria monocytogenes. The properties of K41 bacteriocin-like inhibitory substance add to its safety as a biopreservative produced by a generally recognized as safe (GRAS) bacterium suggesting it can be used in hurdle technology for ready-to-eat foods as one of the main sources of Listeria contaminations. © 2013 Institute of Food Technologists®

Molecular adsorption steers bacterial swimming at the air/water interface.

PubMed

Morse, Michael; Huang, Athena; Li, Guanglai; Maxey, Martin R; Tang, Jay X

2013-07-02

Microbes inhabiting Earth have adapted to diverse environments of water, air, soil, and often at the interfaces of multiple media. In this study, we focus on the behavior of Caulobacter crescentus, a singly flagellated bacterium, at the air/water interface. Forward swimming C. crescentus swarmer cells tend to get physically trapped at the surface when swimming in nutrient-rich growth medium but not in minimal salt motility medium. Trapped cells move in tight, clockwise circles when viewed from the air with slightly reduced speed. Trace amounts of Triton X100, a nonionic surfactant, release the trapped cells from these circular trajectories. We show, by tracing the motion of positively charged colloidal beads near the interface that organic molecules in the growth medium adsorb at the interface, creating a high viscosity film. Consequently, the air/water interface no longer acts as a free surface and forward swimming cells become hydrodynamically trapped. Added surfactants efficiently partition to the surface, replacing the viscous layer of molecules and reestablishing free surface behavior. These findings help explain recent similar studies on Escherichia coli, showing trajectories of variable handedness depending on media chemistry. The consistent behavior of these two distinct microbial species provides insights on how microbes have evolved to cope with challenging interfacial environments. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Proteolytic and amylolytic enzymes from a newly isolated Bacillus mojavensis SA: Characterization and applications as laundry detergent additive and in leather processing.

PubMed

Hammami, Amal; Fakhfakh, Nahed; Abdelhedi, Ola; Nasri, Moncef; Bayoudh, Ahmed

2018-03-01

The present work aims to study the simultaneous production of highly alkaline proteases and thermostable α-amylases by a newly isolated bacterium Bacillus mojavensis SA. The optimum pH and temperature of amylase activity were 9.0 and 55°C, respectively, while those of the proteolytic activity were 12.0 and 60°C, respectively. Both α-amylase and protease enzymes showed a high stability towards a wide range of pH and temperature. Furthermore, SA crude enzymes were relatively stable towards non-ionic (Tween 20, Tween 80 and Triton X-100) and anionic (SDS) surfactants, as well as oxidizing agents. Both activities were improved by the presence of polyethylene glycol 4000 and glycerol. Additionally, the crude enzymes showed excellent stability against various solid and liquid detergents. Wash performance analysis revealed that the SA crude enzymes exhibited a remarkable efficiency in the removal of a variety type of stains, such as blood, chocolate, coffee and oil. On the other side, SA proteases revealed a potential dehairing activity of animal hide without chemical assistance or fibrous proteins hydrolysis. Thus, considering their promising properties, B. mojavensis SA crude enzymes could be used in several biotechnological bioprocesses. Copyright © 2017 Elsevier B.V. All rights reserved.

Preparation of the Nuclear Matrix for Parallel Microscopy and Biochemical Analyses.

PubMed

Wilson, Rosemary H C; Hesketh, Emma L; Coverley, Dawn

2016-01-04

Immobilized proteins within the nucleus are usually identified by treating cells with detergent. The detergent-resistant fraction is often assumed to be chromatin and is described as such in many studies. However, this fraction consists of both chromatin-bound and nuclear-matrix-bound proteins. To investigate nuclear-matrix-bound proteins alone, further separation of these fractions is required; the DNA must be removed so that the remaining proteins can be compared with those from untreated cells. This protocol uses a nonionic detergent (Triton X-100) to remove membranes and soluble proteins from cells under physiologically relevant salt concentrations, followed by extraction with 0.5 m NaCl, digestion with DNase I, and removal of fragmented DNA. It uses a specialized buffer (cytoskeletal buffer) to stabilize the cytoskeleton and nuclear matrix in relatively gentle conditions. Nuclear matrix proteins can then be assessed by either immunofluorescence (IF) and immunoblotting (IB). IB has the advantage of resolving different forms of a protein of interest, and the soluble fractions can be analyzed. The major advantage of IF analysis is that individual cells (rather than homogenized populations) can be monitored, and the spatial arrangement of proteins bound to residual nuclear structures can be revealed. © 2016 Cold Spring Harbor Laboratory Press.

Partial purification and kinetic characterization of acid phosphatase from garlic seedling.

PubMed

Yenigün, Begüm; Güvenilir, Yüksel

2003-01-01

The objective of this study was to obtain purer acid phosphatases than produced by prior art by operating under conditions that improve the final product. The study features are the use of a mild nonionic detergent, 40-80% saturation with (NH4)2SOm4, maintained at low temperature to remove impurity, and the use of chromatografic columns to concentrate the acid phosphatase and remove non-acid phosphatase proteins with lower or higher molecular weights. Acid phosphatase was isolated and purified from garlic seedlings by a streamline method without the use of proteolytic and lipolytic enzymes, butanol, or other organic solvents. Grown garlic seedlings of 10- 15 cm height were homogenized with 0.1 M acetate buffer containing 0.1 M NaCl and 0.1% Triton X-100. After homogenization, the supernatant was filtered with paper filters. Filtrated supernatant was cooled to 4 degrees C, followed by a threestep fractionation of the proteins with ammonium sulfate. The crude enzyme was isolated as a green precipitate that was dissolved in a small amount of 0.1 M acetate buffer containing 0.1 M NaCl and 0.1% Triton X-100. Garlic seedling acid phosphatase was purified with ion-exchange chromatography (DEAE cellulose). The column was equilibrated with 0.1 M acetate buffer. Acid phosphatase was purified 40-fold from the starting material. The specific activity of the pure enzyme was 168 U/mg. A variety of stability and activity profiles were determined for the purified garlic seedling acid phosphatase: optimum pH, optimum temperature, pH stability, temperature stability, thermal inactivation, substrate specificity, effect of enzyme concentration, effect of substrate concentration, activation energy, and effect of inhibitor and activator. The molecular mass of acid phosphatase was estimated to be 58 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum pH was 5.7 and the optimum temperature was 50 degrees C. The enzyme was stable at pH 4.0-10.0 and 40-60 degrees C. Activation energy was between 10 and 20 kcal, and as Michaelis Menten coefficients, Vm values were 100 and 20 mM/s and Km values were 21.27 and 8.33 mM for paranitrophenylphosphate and paranitrophenyl, respectively. Studies of the effect of metal ions on enzyme activity showed both an activating and a deactivating effect. While Cu, Mo, and Mn showed strong inhibitory effects, Na, Ca, and K were the significant activators of acid phosphatase.

Optimization of conditions for transient Agrobacterium-mediated gene expression assays in Arabidopsis.

PubMed

Kim, Mi Jung; Baek, Kon; Park, Chung-Mo

2009-08-01

Transient genetic transformation of plant organs is an indispensable way of studying gene function in plants. This study was aimed to develop an optimized system for transient Agrobacterium-mediated transformation of the Arabidopsis leaves. The beta-glucuronidase (GUS) reporter gene was employed to evaluate growth and biochemical parameters that influence the levels of transient expression. The effects of plant culture conditions, Agrobacterial genetic backgrounds, densities of Agrobacterial cell suspensions, and of several detergents were analyzed. We found that optimization of plant culture conditions is the most critical factor among the parameters analyzed. Higher levels of transient expression were observed in plants grown under short day conditions (SDs) than in plants grown under long day conditions (LDs). Furthermore, incubation of the plants under SDs at high relative humidity (85-90%) for 24 h after infiltration greatly improved the levels of transient expression. Under the optimized culture conditions, expression of the reporter gene reached the peak 3 days after infiltration and was rapidly decreased after the peak. Among the five Agrobacterial strains examined, LAB4404 produced the highest levels of expression. We also examined the effects of detergents, including Triton X-100, Tween-20, and Silwet L-77. Supplementation of the infiltration media either with 0.01% Triton X-100 or 0.01% Tween-20 improved the levels of expression by approximately 1.6-fold. Our observations indicate that transient transformation of the Arabidopsis leaves in the infiltration media supplemented with 0.01% Triton X-100 and incubation of the infiltrated plants under SDs at high relative humidity are necessary for maximal levels of expression.

ABCA1, ABCG1, and ABCG4 Are Distributed to Distinct Membrane Meso-Domains and Disturb Detergent-Resistant Domains on the Plasma Membrane

PubMed Central

Sano, Osamu; Ito, Shiho; Kato, Reiko; Shimizu, Yuji; Kobayashi, Aya; Kimura, Yasuhisa; Kioka, Noriyuki; Hanada, Kentaro; Ueda, Kazumitsu; Matsuo, Michinori

2014-01-01

ATP-binding cassette A1 (ABCA1), ABCG1, and ABCG4 are lipid transporters that mediate the efflux of cholesterol from cells. To analyze the characteristics of these lipid transporters, we examined and compared their distributions and lipid efflux activity on the plasma membrane. The efflux of cholesterol mediated by ABCA1 and ABCG1, but not ABCG4, was affected by a reduction of cellular sphingomyelin levels. Detergent solubility and gradient density ultracentrifugation assays indicated that ABCA1, ABCG1, and ABCG4 were distributed to domains that were solubilized by Triton X-100 and Brij 96, resistant to Triton X-100 and Brij 96, and solubilized by Triton X-100 but resistant to Brij 96, respectively. Furthermore, ABCG1, but not ABCG4, was colocalized with flotillin-1 on the plasma membrane. The amounts of cholesterol extracted by methyl-β-cyclodextrin were increased by ABCA1, ABCG1, or ABCG4, suggesting that cholesterol in non-raft domains was increased. Furthermore, ABCG1 and ABCG4 disturbed the localization of caveolin-1 to the detergent-resistant domains and the binding of cholera toxin subunit B to the plasma membrane. These results suggest that ABCA1, ABCG1, and ABCG4 are localized to distinct membrane meso-domains and disturb the meso-domain structures by reorganizing lipids on the plasma membrane; collectively, these observations may explain the different substrate profiles and lipid efflux roles of these transporters. PMID:25302608

Structuration in the Interface of Direct and Reversed Micelles of Sucrose Esters, Studied by Fluorescent Techniques

PubMed Central

Sandoval, Catalina; Ortega, Anakenna; Sanchez, Susana A.; Morales, Javier; Gunther, German

2015-01-01

Background Reactors found in nature can be described as micro-heterogeneous systems, where media involved in each micro-environment can behave in a markedly different way compared with the properties of the bulk solution. The presence of water molecules in micro-organized assemblies is of paramount importance for many chemical processes, ranging from biology to environmental science. Self-organized molecular assembled systems are frequently used to study dynamics of water molecules because are the simplest models mimicking biological membranes. The hydrogen bonds between sucrose and water molecules are described to be stronger (or more extensive) than the ones between water molecules themselves. In this work, we studied the capability of sucrose moiety, attached to alkyl chains of different length, as a surface blocking agent at the water-interface and we compared its properties with those of polyethylenglycol, a well-known agent used for this purposes. Published studies in this topic mainly refer to the micellization process and the stability of mixed surfactant systems using glycosides. We are interested in the effect induced by the presence of sucrose monoesters at the interface (direct and reverse micelles) and at the palisade (mixtures with Triton X-100). We believe that the different functional group (ester), the position of alkyl chain (6-O) and the huge capability of sucrose to interact with water will dramatically change the water structuration at the interface and at the palisade, generating new possibilities for technological applications of these systems. Results Our time resolved and steady state fluorescence experiments in pure SEs micelles show that sucrose moieties are able to interact with a high number of water molecules promoting water structuration and increased viscosity. These results also indicate that the barrier formed by sucrose moieties on the surface of pure micelles is more effective than the polyoxyethylene palisade of Triton X-100. The fluorescence quenching experiments of SEs at the palisade of Triton X-100 micelles indicate a blocking effect dependent on the number of methylene units present in the hydrophobic tail of the surfactant. A remarkable blocking effect is observed when there is a match in size between the hydrophobic regions forming the apolar core (lauryl SE/ Triton X-100). This blocking effect disappears when a mismatch in size between hydrophobic tails, exists due to the disturbing effect on the micelle core. PMID:25905632

Molecular assessment of collagen denaturation in decellularized tissues using a collagen hybridizing peptide.

PubMed

Hwang, Jeongmin; San, Boi Hoa; Turner, Neill J; White, Lisa J; Faulk, Denver M; Badylak, Stephen F; Li, Yang; Yu, S Michael

2017-04-15

Decellularized extracellular matrix (ECM) derived from tissues and organs are emerging as important scaffold materials for regenerative medicine. Many believe that preservation of the native ECM structure during decellularization is highly desirable. However, because effective techniques to assess the structural damage in ECM are lacking, the disruptive effects of a decellularization method and the impact of the associated structural damage upon the scaffold's regenerative capacity are often debated. Using a novel collagen hybridizing peptide (CHP) that specifically binds to unfolded collagen chains, we investigated the molecular denaturation of collagen in the ECM decellularized by four commonly used cell-removing detergents: sodium dodecyl sulfate (SDS), 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), sodium deoxycholate (SD), and Triton X-100. Staining of the detergent-treated porcine ligament and urinary bladder matrix with carboxyfluorescein-labeled CHP demonstrated that SDS and Triton X-100 denature the triple helical collagen molecule while CHAPS and SD do not, although second harmonic generation imaging and transmission electron microscopy (TEM) revealed that all four detergents disrupt collagen fibrils. Our findings from the CHP staining were further confirmed by the circular dichroism spectra of intact triple helical collagen molecules in CHAPS and SD solutions, and the TEM images of CHP-conjugated gold nanoparticles binding only to the SDS and Triton X-100 treated collagen fibrils. CHP is a powerful new tool for direct and reliable measurement of denatured collagen molecules in decellularized tissues. It is expected to have wide applications in the development and standardization of the tissue/organ decellularization technology. Preservation of the native ECM structure in decellularized tissues is highly desirable, since denaturation of ECM molecules (e.g., collagen) during decellularization can strongly influence the cellular response. Unfortunately, conventional techniques (SEM, SHG) are not conducive to identifying denatured collagen molecules in tissues. We demonstrate the first investigation into the molecular denaturation of collagen in decellularized ECM enabled by a novel Collagen Hybridizing Peptide (CHP) that specifically binds to unfolded collagen chains. We show that SDS and Triton X-100 denature collagen molecules while CHAPS and SD cannot. Such detection has been nearly impossible with other existing techniques. The CHP technique will advance our understanding about the effect of the cell-removing process on ECM, and lead to development of the decellularization technology. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Molecular assessment of collagen denaturation in decellularized tissues using a collagen hybridizing peptide

PubMed Central

Hwang, Jeongmin; San, Boi Hoa; Turner, Neill J.; White, Lisa J.; Faulk, Denver M.; Badylak, Stephen F.; Li, Yang; Yu, S. Michael

2017-01-01

Decellularized extracellular matrix (ECM) derived from tissues and organs are emerging as important scaffold materials for regenerative medicine. Many believe that preservation of the native ECM structure during decellularization is highly desirable. However, because effective techniques to assess the structural damage in ECM are lacking, the disruptive effects of a decellularization method and the impact of the associated structural damage upon the scaffold’s regenerative capacity are often debated. Using a novel collagen hybridizing peptide (CHP) that specifically binds to unfolded collagen chains, we investigated the molecular denaturation of collagen in the ECM decellularized by four commonly used cellremoving detergents: sodium dodecyl sulfate (SDS), 3-[(3-cholamidopropyl)dimethylammonio]-1-propa nesulfonate (CHAPS), sodium deoxycholate (SD), and Triton X-100. Staining of the detergent-treated porcine ligament and urinary bladder matrix with carboxyfluorescein-labeled CHP demonstrated that SDS and Triton X-100 denature the triple helical collagen molecule while CHAPS and SD do not, although second harmonic generation imaging and transmission electron microscopy (TEM) revealed that all four detergents disrupt collagen fibrils. Our findings from the CHP staining were further confirmed by the circular dichroism spectra of intact triple helical collagen molecules in CHAPS and SD solutions, and the TEM images of CHP-conjugated gold nanoparticles binding only to the SDS and Triton X-100 treated collagen fibrils. CHP is a powerful new tool for direct and reliable measurement of denatured collagen molecules in decellularized tissues. It is expected to have wide applications in the development and standardization of the tissue/organ decellularization technology. Statement of Significance Preservation of the native ECM structure in decellularized tissues is highly desirable, since denaturation of ECM molecules (e.g., collagen) during decellularization can strongly influence the cellular response. Unfortunately, conventional techniques (SEM, SHG) are not conducive to identifying denatured collagen molecules in tissues. We demonstrate the first investigation into the molecular denaturation of collagen in decellularized ECM enabled by a novel Collagen Hybridizing Peptide (CHP) that specifically binds to unfolded collagen chains. We show that SDS and Triton X-100 denature collagen molecules while CHAPS and SD cannot. Such detection has been nearly impossible with other existing techniques. The CHP technique will advance our understanding about the effect of the cell-removing process on ECM, and lead to development of the decellularization technology. PMID:28161576

Triton: topside ionosphere and nitrogen escape.

PubMed

Yung, Y L; Lyons, J R

1990-09-01

The principal ion in the ionosphere of Triton is N+. Energetic electrons of magnetospheric origin are the primary source of ionization, with a smaller contribution due to photoionization. To explain the topside plasma scale height, we postulate that N+ ions escape from Triton. The loss rate is 3.4 x 10(7) cm-2 s-1 or 7.9 x 10(24) ions s-1. Dissociative recombination of N2+ produces neutral exothermic fragments that can escape from Triton. The rate is estimated to be 8.6 x 10(6) N cm-2 s-1 or 2.0 x 10(24) atoms s-1. Implications for the magnetosphere of Neptune and Triton's evolution are discussed.

Acrosin activity in turkey spermatozoa: assay by clinical method and effect of zinc and benzamidine on the activity.

PubMed

Glogowski, J; Jankowski, J; Faruga, A; Ottobre, J S; Ciereszko, A

2001-09-15

We optimized a clinical assay developed for measuring total acrosin activity for mammalian and fish semen for use in turkey spermatozoa. The main modifications included dilution of semen to a final concentration of 25 to 1000 x 10(3) spermatozoa, an increase of Triton X-100 concentration to 0.05% and 1 hr preincubation without substrate, Acrosin activity in turkey spermatozoa was much higher than in human spermatozoa (about 100-times) but similar to that of boar sperm. To optimize this assay for turkey spermatozoa, it was necessary to use higher Triton X-100 concentrations in the reaction mixture. There was a better catalytic efficiency at higher temperatures and a special requirement for a preincubation period for proacrosin activation. We observed high inhibition of acrosin activity by zinc added during preincubation (90% at 0.01 mM of zinc chloride). Benzamidine also inhibited turkey acrosin, and the extent of inhibition was similar for the incubation or preincubation period. When zinc ions were added during incubation, this inhibition was lower (24%). The results suggest that zinc influences proacrosin activation of turkey spermatozoa. This influence may be important for successful long-term storage of spermatozoa in the hen's oviduct.

Identification of AQP5 in lipid rafts and its translocation to apical membranes by activation of M3 mAChRs in interlobular ducts of rat parotid gland.

PubMed

Ishikawa, Yasuko; Yuan, Zhenfang; Inoue, Noriko; Skowronski, Mariusz T; Nakae, Yoshiko; Shono, Masayuki; Cho, Gota; Yasui, Masato; Agre, Peter; Nielsen, Søren

2005-11-01

Aquaporin-5 (AQP5), an apical plasma membrane (APM) water channel in salivary glands, lacrimal glands, and airway epithelium, has an important role in fluid secretion. M(3) muscarinic acetylcholine receptor (mAChR)-induced changes in AQP5 localization in rat parotid glands were investigated with immunofluorescence or immunoelectron microscopy, detergent solubility, and gradient density floatation assays. Confocal microscopy revealed AQP5 localization in intracellular vesicles of interlobular duct cells in rat parotid glands and AQP5 trafficking to the APM 10 min after injection of the mAChR agonist cevimeline. Conversely, 60 min after injection, there was a diffuse pattern of AQP5 staining in the cell cytoplasm. The calcium ionophore A-23187 mimicked the effects of cevimeline. Immunoelectron microscopic studies confirmed that cevimeline induced AQP5 trafficking from intracellular structures to APMs in the interlobular duct cells of rat parotid glands. Lipid raft markers flotillin-2 and GM1 colocalized with AQP5 and moved with AQP5 in response to cevimeline. Under control conditions, the majority of AQP5 localized in the Triton X-100-insoluble fraction and floated to the light-density fraction on discontinuous density gradients. After 10-min incubation of parotid tissue slices with cevimeline or A-23187, AQP5 levels decreased in the Triton X-100-insoluble fraction and increased in the Triton X-100-soluble fraction. Thus AQP5 localizes in the intracellular lipid rafts, and M(3) mAChR activation induces AQP5 trafficking to the APM with lipid rafts via intracellular Ca(2+) signaling and induces AQP5 dissociation from lipid rafts to nonrafts on the APM in the interlobular duct cells of rat parotid glands.

Extracellular production of human parathyroid hormone as a thioredoxin fusion form in Escherichia coli by chemical permeabilization combined with heat treatment.

PubMed

Fu, Xiang-Yang; Tong, Wang-Yu; Wei, Dong-Zhi

2005-01-01

A pET system encoding the fusion protein gene of thioredoxin (Trx) and human parathyroid hormone (hPTH) was introduced into Escherichia coli BL21 (DE3). Recombinant Trx-hPTH fusion protein was expressed in soluble form in the cytoplasm of the E. coli transformant. To recover Trx-hPTH from the E. coli culture efficiently, a novel tactic was developed by adding Triton X-100 into the fermentation culture at the exponential growth phase of E. coli and by heat treatment of the culture at the end of the fermentation. A concentration of 1% (v/v) Triton X-100 was added into the culture at the same time as IPTG addition after optimization. Under these conditions, addition of Triton X-100 had little effect on the cell growth, but more than 75% of the total recombinant Trx-hPTH was released into the fermentation broth. Also, a much higher volumetric yield of recombinant Trx-hPTH could be obtained with protein release compared to yield without protein release. Simultaneously, owing to the highly thermal stability of Trx-hPTH fusion protein, heat treatment of the fermentation broth at 80 degrees C for 15 min at the end of fermentation was employed for primary purification. Results demonstrated that heat treatment not only boosted further release of the recombinant Trx-hPTH fusion protein into the fermentation broth but also precipitated/denatured most of the nontarget proteins released in the broth. The tactics described herein integrated the fermentation process with subsequent recovery steps and thus provided a valuable and economical method for the production of Trx-hPTH and maybe some other Trx fusions in E. coli.

Triton-polyacrylamide gel electrophoresis and leucine aminopeptidase activity staining detect Triton-slowed bands including high-molecular-mass aminopeptidase N (CD13) isoform in cholestatic patient sera.

PubMed

Kawai, Makoto; Hara, Yukichi

2006-02-01

Western blotting of aminopeptidase N (APN) detects a high-molecular-mass isoform (260 kDa) [M. Kawai, Y. Otake, Y. Hara High-molecular-mass isoform of aminopeptidase N/CD13 in serum from cholestatic patients. Clin Chim Acta 330 (2003) 141-149] in cholestatic patient serum but is time-consuming. Human sera were electrophoresed on polyacrylamide gel containing Triton-X100 (Triton-PAGE) and stained with leucine-B-naphthylamide (LAP-staining). The stained bands were eluted from the gel, treated with N- and O-glycosidase if necessary, and analyzed by Western blotting [M. Kawai, Y. Otake, Y. Hara High-molecular-mass isoform of aminopeptidase N/CD13 in serum from cholestatic patients. Clin Chim Acta 330 (2003) 141-149]. Triton-PAGE and LAP-staining clearly detected fast bands in all the sera examined. Almost parallel with leucine aminopeptidase activity, slow bands were strongly stained in all 11 cholestatic patients but clearly stained in 3 out of 14 patients with hepatobiliary diseases other than cholestasis. PAGE with various concentrations of Triton showed that Triton slows down slow bands but not fast bands. Western blotting showed that Triton-PAGE-slow bands of cholestasis contained 140 and 260-kDa APN and that fast bands were slightly smaller than monomer-size slow bands after glycosidase treatment. Less time-consuming than Western blotting, Triton-PAGE and LAP-staining detect novel APN bands slowed by Triton and partly composed of the high-molecular-mass isoform in cholestasis. The slow bands seem to be homodimers of APN with transmembrane anchors. The polypeptide of the fast band seems to be processed differently from that of the slow band.

Complementary experimental-simulational study of surfactant micellar phase in the extraction process of metallic ions: Effects of temperature and salt concentration

NASA Astrophysics Data System (ADS)

Soto-Ángeles, Alan Gustavo; Rodríguez-Hidalgo, María del Rosario; Soto-Figueroa, César; Vicente, Luis

2018-02-01

The thermoresponsive micellar phase behaviour that exhibits the Triton-X-100 micelles by temperature effect and addition of salt in the extraction process of metallic ions was explored from mesoscopic and experimental points. In the theoretical study, we analyse the formation of Triton-X-100 micelles, load and stabilization of dithizone molecules and metallic ions extraction inside the micellar core at room temperature; finally, a thermal analysis is presented. In the experimental study, the spectrophotometric outcomes confirm the solubility of the copper-dithizone complex in the micellar core, as well as the extraction of metallic ions of aqueous environment via a cloud-point at 332.2 K. The micellar solutions with salt present a low absorbance value compared with the micellar solutions without salt. The decrease in the absorbance value is attributed to a change in the size of hydrophobic region of colloidal micelles. All transitory stages of extraction process are discussed and analysed in this document.

An alkaline and surfactant-tolerant lipase from Trichoderma lentiforme ACCC30425 with high application potential in the detergent industry.

PubMed

Wang, Yuzhou; Ma, Rui; Li, Shigui; Gong, Mingbo; Yao, Bin; Bai, Yingguo; Gu, Jingang

2018-06-05

Alkaline lipases with adaptability to low temperatures and strong surfactant tolerance are favorable for application in the detergent industry. In the present study, a lipase-encoding gene, TllipA, was cloned from Trichoderma lentiforme ACCC30425 and expressed in Pichia pastoris GS115. The purified recombinant TlLipA was found to have optimal activities at 50 °C and pH 9.5 and retain stable over the pH range of 6.0-10.0 and 40 °C and below. When using esters of different lengths as substrates, TlLipA showed preference for the medium length p-nitrophenyl octanoate. In comparison to commercial lipases, TlLipA demonstrated higher tolerance to various surfactants (SDS, Tween 20, and Triton X100) and retained more activities after incubation with Triton X100 for up to 24 h. These favorable characteristics make TlLipA prospective as an additive in the detergent industry.

Polydiacetylene sensor interaction with food sanitizers and surfactants.

PubMed

Zhang, Yueyuan; Northcutt, Julie; Hanks, Tim; Miller, Ian; Pennington, Bill; Jelinek, Raz; Han, Inyee; Dawson, Paul

2017-04-15

Polydiacetylene (PDA) vesicles are of interest as biosensors, particularly for pathogenic bacteria. As part of a food monitoring system, interaction with food sanitizers/surfactants was investigated. PDA vesicles were prepared by inkjet-printing, photopolymerized and characterized by dynamic light scattering (DLS) and UV/Vis spectroscopy. The optical response of PDA vesicles at various concentrations verses a fixed sanitizer/surfactant concentration was determined using a two variable factorial design. Sanitizer/surfactant response at various concentrations over time was also measured. Results indicated that only Vigilquat and TritonX-100 interacted with PDA vesicles giving visible colour change out of 8 sanitizers/surfactants tested. PDA vesicle concentration, sanitizer/surfactant concentration, and time all had a significant (P<0.0001) effect on colour change. As they are highly sensitive to the presence of Vigilquat and TritonX-100, PDA sensors could be used to detect chemical residues as well as for detection of various contaminants in the food industry. Copyright © 2016. Published by Elsevier Ltd.

Ni-doped (CeO2- δ )-YSZ mesoarchitectured with nanocrystalline framework: the effect of thermal treatment on structure, surface chemistry and catalytic properties in the partial oxidation of methane (CPOM)

NASA Astrophysics Data System (ADS)

Somacescu, Simona; Florea, Mihaela; Osiceanu, Petre; Calderon-Moreno, Jose Maria; Ghica, Corneliu; Serra, Jose Manuel

2015-11-01

Ni-doped (CeO2- δ )-YSZ (5 mol% Ni oxide, 10 mol% ceria) mesoarchitectures (MA) with nanocrystalline framework have been synthesized by an original, facile and cheap approach based on Triton X100 nonionic surfactant as template and water as solvent at a strong basic pH value. Following the hydrothermal treatment under autogenous pressure ( 18 bars), Ni, Ce, Y, and Zr were well ordered as MA with nanocrystalline framework, assuring thermal stability. A comprehensive investigation of structure, texture, morphology, and surface chemistry was performed by means of a variety of complementary techniques (X-Ray Diffraction, XRD; Raman Spectroscopy, RS; Brunauer—Emmett—Teller, BET; Temperature—Programmed Reduction, TPR; Transmission Electron Microscopy, TEM and DF-STEM; X-ray Photoelectron Spectroscopy, XPS; Catalytic activity and selectivity). N2 sorption measurements highlighted that the mesoporous structure is formed at 600 °C and remains stable at 800 °C. At 900 °C, the MA collapses, favoring the formation of macropores. The XRD and Raman Spectroscopy of all samples showed the presence of a pure, single phase with fluorite-type structure. At 900 °C, an increased tetragonal distortion of the cubic lattice was observed. The surface chemistry probed by XPS exhibits a mixture of oxidation states (Ce3+ + Ce4+) with high percentage of Ce3+ valence state 35 % and (Ni3+ and Ni2+) oxidation states induced by the thermal treatment. These nanoparticles assembled into MA show high stability and selectivity over time in catalytic partial oxidation of methane (CPOM). These promising performances suggest an interesting prospect for introduction as anode within IT-SOFC assemblies.

Physical characteristics of the gonadotropin receptor-hormone complexes formed in vivo and in vitro.

PubMed Central

Dufau, M L; Podesta, E J; Catt, K J

1975-01-01

The physical properties of detergent-solubilized gonadotropin receptor-hormone complexes, determined by density gradient centrifugation and gel filtration, were compared after in vivo and in vitro labeling of specific ovarian binding sites with radioiodinated human chorionic gonadotropin (hCG). Following intravenous administration of biologically active 125I-labeled hCG, up to 50% of the gonadotropin tracer was bound to the luteinized ovaries of immature female rats treated with pregnant mare serum/human chorionic gonadotropin. Comparable binding of 125I-labeled hCG was observed after equilibration of ovarian particles with the labeled hormone in vitro. The sedimentation properties of the solubilized receptor-hormone complexes formed in vivo were identical with those derived for the corresponding complexes formed in vitro and extracted with Triton X-100 and Lubrol PX, with sedimentation constants of 8.8 S for the Triton-solubilized complex and 7.0 S for the complex extracted with Lubrol PX. During analytical gel filtration of the Triton-solubilized receptor-hormone complex on Sepharose 6B in 0.1% Triton X-100, the partition coefficient (Kav) of the "in vivo" complex (0.32) was not significantly different from that of the complex formed in vitro (0.29). Gel filtration of the Lubrol-solubilized ovarian particles on Sepharose 6B in 0.5% Lubrol PX gave Kav values for the "in vivo" and "in vitro" labeled complexes of 0.36 and 0.32, respectively. These findings demonstrate that the physical properties of size and shape which determine the partition coefficient and sedimentation characteristics of detergent-solubilized gonadotropin receptor-hormone complexes formed in vitro are not distinguishable from those of the complexes extracted after specific interaction of the ovarian gonadotropin receptors with radioiodinated hCG in vivo. PMID:165502

Kinetics of degradation of surfactant-solubilized fluoranthene by a Sphingomonas paucimobilis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willumsen, P.A.; Arvin, E.

To achieve a better quantitative understanding of the stimulating or inhibiting effect of surfactants on the metabolism of polycyclic aromatic hydrocarbons (PAHs), a biodegradation model describing solubilization, bioavailability, and biodegradation of crystalline fluoranthene is proposed and used to model experimental data. The degradation was investigated in batch systems containing the PAH-degrading bacterium Sphingomonas paucimobilis strain EPA505, the nonionic surfactant Triton X-100, and a fluoranthene-amended liquid mineral salts medium. Surfactant-enhanced biodegradation is complex; however, the biodegradation model predicted fluoranthene disappearance and the initial mineralization well. Surfactant-amendment did increase fluoranthene mineralization rates by strain EPA505; however, the increases were not proportional tomore » the rates of fluoranthene solubilization. The surfactant clearly influenced the microbial PAH metabolism as indicated by a rapid accumulation of colored products and by a surfactant -related decreased in the overall extent of fluoranthene mineralization. Model estimations of the bioavailability of micelle-solubilized fluoranthene, the relatively fast fluoranthene disappearance, and the accumulation of extracellular compounds in the degradation system suggest that low availability of micellar fluoranthene is not the only factor controlling surfactant-enhanced biodegradation. Also factors such as the extent of accumulation and bioavailability of the PAH metabolites and the crystalline solubilization rate in the presence of surfactants may determine the overall effect of surfactant-enhanced biodegradation of high molecular weight PAHs.« less

Soap bubbles in analytical chemistry. Conductometric determination of sub-parts per million levels of sulfur dioxide with a soap bubble.

PubMed

Kanyanee, Tinakorn; Borst, Walter L; Jakmunee, Jaroon; Grudpan, Kate; Li, Jianzhong; Dasgupta, Purnendu K

2006-04-15

Soap bubbles provide a fascinating tool that is little used analytically. With a very low liquid volume to surface area ratio, a soap bubble can potentially provide a very useful interface for preconcentration where mass transfer to an interfacial surface is important. Here we use an automated system to create bubbles of uniform size and film thickness. We utilize purified Triton-X 100, a nonionic surfactant, to make soap bubbles. We use such bubbles as a gas-sampling interface. Incorporating hydrogen peroxide into the bubble provides a system where electrical conductance increases as the bubble is exposed to low concentrations of sulfur dioxide gas. We theoretically derive the conductance of a hollow conducting spherical thin film with spherical cap electrodes. We measure the film thickness by incorporating a dye in the bubble making solution and laser transmission photometry and find that it agrees well with the geometrically computed thickness. With the conductance of the bubble-making soap solution being measured by conventional methods, we show that the measured values of the bubble conductance with known bubble and electrode dimensions closely correspond to the theoretically computed value. Finally, we demonstrate that sub-ppm levels of SO(2) can readily be detected by the conductivity change of a hydrogen peroxide-doped soap bubble, measured in situ, when the gas flows around the bubble.

Effect of Four Commonly Used Dissolution Media Surfactants on Pancreatin Proteolytic Activity.

PubMed

Guncheva, Maya; Stippler, Erika

2017-05-01

Proteolytic enzymes are often used in dissolution testing of cross-linked gelatin capsules that do not conform to the dissolution specification. Their catalytic activity, however, can be affected when they are added to a dissolution media containing solubility enhancers, such as surfactants. The aim of this study was to assess the activity of pancreatic proteases in presence of four commonly used surfactants. We found that pancreatin exhibits remarkable proteolytic activity in the presence of Tween 80, even at the concentrations as high as 250 times its critical micelle concentration (cmc) in water, whereas, Triton X-100 enhanced the proteolytic activity of pancreatin when added at concentrations above its cmc in water. Both surfactants are non-ionic surfactants. On the other hand, sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB), which are ionic surfactants, have a detrimental effect on the proteolytic activity of pancreatin. For example, a 50% reduction of the pancreatin activity was found in samples which contain a minor amount of SDS (0.05% w/v) in comparison to a surfactant-free reaction. Additionally, no activity was observed for the pancreatin-SDS samples which were incubated for 30 min at 40°C prior to testing. CTAB had an impact on pancreatin activity at concentrations higher than its cmc. Data from this manuscript can be used as a benchmark for optimization of the dissolution procedures that require use of both surfactants and enzymes.

Sensitized spectrophotometric determination of Cr(III) ion for speciation of chromium ion in surfactant media using alpha-benzoin oxime.

PubMed

Ghaedi, Mehrorang; Asadpour, Enayat; Vafaie, Azam

2006-01-01

A simple and accurate micellanized spectrophotometric method for determination of trace amounts of Cr(III) ion in tab and top water and a synthetic mixture has been described. The micellar method is based on effect of organized molecular assemblies such as micelles in spectrophotometric measurement due to their effect on the systems of interest. The ability of micellar system in solubilizing of sparingly soluble ligand or complexes has been used for increasing figures of merit of an analytical method. Due to solubility increasing in aqueous media requirement for a primary extraction can be eliminated. Using the alpha-benzoin oxime (alpha-BO) spectrophotometric determination of Cr(III) ion has been performed and results are compared. The spectrophotometric determination of Cr(III) ion using alpha-BO in the presence of non-ionic surfactant Triton X-100 has been performed. The influence of type and amount of surfactant, pH, complexation time and amount of ligand were examined. Finally, the repeatability, accuracy and the effect of interfering ions on the determination of Cr(III) ion was evaluated. The proposed methods successfully with recovery yield of almost 100% have been applied to the rapid and simple determination of Cr(III) ion in the real samples. There is a good agreement between methods and atomic absorption spectrometry. The Beers law is obeyed over the concentration range of 0.1-13.7 microg mL(-1) for micellar media. The detection limit is 0.8 ng mL(-1). The molar absorptivity of complex is 5350 L mol(-1) cm(-1).

Sensitized spectrophotometric determination of Cr(III) ion for speciation of chromium ion in surfactant media using α-benzoin oxime

NASA Astrophysics Data System (ADS)

Ghaedi, Mehrorang; Asadpour, Enayat; Vafaie, Azam

2006-01-01

A simple and accurate micellanized spectrophotometric method for determination of trace amounts of Cr(III) ion in tab and top water and a synthetic mixture has been described. The micellar method is based on effect of organized molecular assemblies such as micelles in spectrophotometric measurement due to their effect on the systems of interest. The ability of micellar system in solubilizing of sparingly soluble ligand or complexes has been used for increasing figures of merit of an analytical method. Due to solubility increasing in aqueous media requirement for a primary extraction can be eliminated. Using the α-benzoin oxime (α-BO) spectrophotometric determination of Cr(III) ion has been performed and results are compared. The spectrophotometric determination of Cr(III) ion using α-BO in the presence of non-ionic surfactant Triton X-100 has been performed. The influence of type and amount of surfactant, pH, complexation time and amount of ligand were examined. Finally, the repeatability, accuracy and the effect of interfering ions on the determination of Cr(III) ion was evaluated. The proposed methods successfully with recovery yield of almost 100% have been applied to the rapid and simple determination of Cr(III) ion in the real samples. There is a good agreement between methods and atomic absorption spectrometry. The Beers law is obeyed over the concentration range of 0.1-13.7 μg mL-1 for micellar media. The detection limit is 0.8 ng mL-1. The molar absorptivity of complex is 5350 L mol-1 cm-1.

Chemical synthesis of flower-like hybrid Cu(OH)2/CuO electrode: Application of polyvinyl alcohol and triton X-100 to enhance supercapacitor performance.

PubMed

Shinde, S K; Fulari, V J; Kim, D-Y; Maile, N C; Koli, R R; Dhaygude, H D; Ghodake, G S

2017-08-01

In this research article, we report hybrid nanomaterials of copper hydroxide/copper oxide (Cu(OH) 2 /CuO). A thin films were prepared by using a facile and cost-effective successive ionic layer adsorption and reaction (SILAR) method. As-synthesized and hybrid Cu(OH) 2 /CuO with two different surfactants polyvinyl alcohol (PVA) and triton-X 100 (TRX-100) was prepared having distinct morphological, structural, and supercapacitor properties. The surface of the thin film samples were examined by scanning electron microscopy (SEM). A nanoflower-like morphology of the Cu(OH) 2 /CuO nanostructures arranged vertically was evidenced on the stainless steel substrate. The surface was well covered by nanoflake-like morphology and formed a uniform Cu(OH) 2 /CuO nanostructures after treating with surfactants. X-ray diffraction patterns were used to confirm the hybrid phase of Cu(OH) 2 /CuO materials. The electrochemical properties of the pristine Cu(OH) 2 /CuO, PVA:Cu(OH) 2 /CuO, TRX-100:Cu(OH) 2 /CuO films were observed by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy technique. The electrochemical examination reveals that the Cu(OH) 2 /CuO electrode has excellent specific capacitance, 292, 533, and 443Fg -1 with pristine, PVA, and TRX-100, respectively in 1M Na 2 SO 4 electrolyte solution. The cyclic voltammograms (CV) of Cu(OH) 2 /CuO electrode shows positive role of the PVA and TRX-100 to enhance supercapacitor performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Decay-accelerating Factor Limits Hemorrhage-instigated Tissue Injury and Improves Resuscitation Clinical Parameters

DTIC Science & Technology

2012-10-29

thicknesswithacryostat andfixed incoldmethanol for 20min. The fixed sections were permeabilized with 0.2% Triton X-100 in PBS for 10min, then blockedwith 2% bovine ...J Inflamm 1998;48:13. [31] Garratty G. Blood group antigens as tumor markers, parasitic /bacterial/viral receptors, and their association with

The influence of surfactants on cell surface properties of Aeromonas hydrophila during diesel oil biodegradation.

PubMed

Kaczorek, E; Urbanowicz, M; Olszanowski, A

2010-11-01

In this study the capacity of the newly isolated environmental strain Aeromonas hydrophila was evaluated. The influence of three surfactants: rhamnolipides, saponins and Triton X-100 on cell surface properties of the A. hydrophila environmental strain and the biodegradation process of diesel oil was studied. The surface activities in water, a mineral salts medium and in the biological system of all considered surfactants were estimated by means of equilibrium surface tension experiments. The obtained results indicated that critical micellar concentration in the biological system is twice higher for saponins and Triton X-100, and three times higher for rhamnolipides. Our results indicated also, that cell surface hydrophobicity (CSH) of bacteria is correlated with carbon sources in broth medium. The mechanism of surfactant action seems to be dependent on the type and concentration of surfactant used in the studies. The best effect of saponins on diesel oil biodegradation was observed using the A. hydrophila strain, diesel oil biodegradation after 21 days was 78%. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Visualization and analysis of lipopolysaccharide distribution in binary phospholipid bilayers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henning, Maria Florencia; Sanchez, Susana; Bakas, Laura, E-mail: lbakas@biol.unlp.edu.ar

2009-05-22

Lipopolysaccharide (LPS) is an endotoxin released from the outer membrane of Gram-negative bacteria during infections. It have been reported that LPS may play a role in the outer membrane of bacteria similar to that of cholesterol in eukaryotic plasma membranes. In this article we compare the effect of introducing LPS or cholesterol in liposomes made of dipalmitoylphosphatidylcholine/dioleoylphosphatidylcholine on the solubilization process by Triton X-100. The results show that liposomes containing LPS or cholesterol are more resistant to solubilization by Triton X-100 than the binary phospholipid mixtures at 4 {sup o}C. The LPS distribution was analyzed on GUVs of DPPC:DOPC usingmore » FITC-LPS. Solid and liquid-crystalline domains were visualized labeling the GUVs with LAURDAN and GP images were acquired using a two-photon microscope. The images show a selective distribution of LPS in gel domains. Our results support the hypothesis that LPS could aggregate and concentrate selectively in biological membranes providing a mechanism to bring together several components of the LPS-sensing machinery.« less

Studies of the acetylcholinesterase from houseflies (Musca domestica L.) resistant and susceptible to organophosphorus insecticides.

PubMed Central

Devonshire, A L

1975-01-01

Acetylcholinesterase from the heads of insecticide-resistant and -susceptible houseflies (Musca domestica L.) was studied in vitro. The enzymes could not be distinguished electrophoretically, and their behaviour on polyacrylamide-disc-gel electrophoresis was influenced by the presence of Triton X-100 in both the homogenate and the gels. In the absence of detergent, the acetylcholinesterase was heterogeneous, but behaved as a single enzyme when it was present. By analogy with studies of acetylcholinesterase from other sources, these observations were attributed to aggregation of the enzyme when not bound by membranes. The enzyme from resistant flies was more slowly inhibited than the susceptible enzyme, bimolecular rate constants (ki) differing by approx. 4-20-fold for a range of organophosphorus compounds. The kinetics of inhibition of acetylcholinesterase were consistent with the results of electrophoresis, i.e. they corresponded to those of a single enzyme in the presence of Triton X-100, but a mixture of enzymes in its absence. The susceptibility of the more sensitive components in these mixtures was determined. Images PLATE 1 PMID:1180906

Discriminatory Role of Detergent-Resistant Membranes in the Dimerization and Endocytosis of Prostate-Specific Membrane Antigen.

PubMed

Schmidt, Sonja; Gericke, Birthe; Fracasso, Giulio; Ramarli, Dunia; Colombatti, Marco; Naim, Hassan Y

2013-01-01

Prostate-specific membrane antigen (PSMA) is a type-II membrane glycoprotein that was initially identified in LNCaP cells. It is expressed at elevated levels in prostate cancer. In view of the correlation between the expression levels of PSMA and disease grade and stage, PSMA is considered to be one of the most promising biomarkers in the diagnosis and treatment of prostate cancer. In LNCaP cells PSMA undergoes internalization via clathrin-coated pits followed by accumulation in the endosomes. PSMA associates with different types of detergent-resistant membranes (DRMs) along the secretory pathway. Its mature form is mainly insoluble in Lubrol WX, but does not associate with Triton X-100-DRMs. To understand the mechanism of PSMA internalization we investigated its association during internalization with DRMs. For this purpose, internalization was induced by antibody cross-linking. We demonstrate at the biochemical and cell biological levels that: [i] exclusively homodimers of PSMA are associated with Lubrol WX-DRMs, [ii] antibody-induced cross-linking of PSMA molecules results in a time-dependent partitioning into another DRMs type, namely Triton X-100-DRMs, and [iii] concomitant with its association with Triton-X-100-DRMs internalization of PSMA occurs along tubulin filaments. In a previous work (Colombatti et al. (2009) PLoS One 4: e4608) we demonstrated that the small GTPases RAS and RAC1 and the MAPKs p38 and ERK1/2 are activated during antibody cross-linking. As downstream effects of this activation we observed a strong induction of NF-kB associated with an increased expression of IL-6 and CCL5 genes and that IL-6 and CCL5 enhanced the proliferative potential of LNCaP cells synergistically. These observations together with findings reported here hypothesize a fundamental role of DRMs during activation of PSMA as platforms for trafficking, endocytosis and signalling. Understanding these mechanisms constitutes an essential prerequisite for utilization of PSMA as a therapeutically suitable target in prostate cancer.

Discriminatory Role of Detergent-Resistant Membranes in the Dimerization and Endocytosis of Prostate-Specific Membrane Antigen

PubMed Central

Schmidt, Sonja; Gericke, Birthe; Fracasso, Giulio; Ramarli, Dunia; Colombatti, Marco; Naim, Hassan Y.

2013-01-01

Prostate-specific membrane antigen (PSMA) is a type-II membrane glycoprotein that was initially identified in LNCaP cells. It is expressed at elevated levels in prostate cancer. In view of the correlation between the expression levels of PSMA and disease grade and stage, PSMA is considered to be one of the most promising biomarkers in the diagnosis and treatment of prostate cancer. In LNCaP cells PSMA undergoes internalization via clathrin-coated pits followed by accumulation in the endosomes. PSMA associates with different types of detergent-resistant membranes (DRMs) along the secretory pathway. Its mature form is mainly insoluble in Lubrol WX, but does not associate with Triton X-100-DRMs. To understand the mechanism of PSMA internalization we investigated its association during internalization with DRMs. For this purpose, internalization was induced by antibody cross-linking. We demonstrate at the biochemical and cell biological levels that: [i] exclusively homodimers of PSMA are associated with Lubrol WX-DRMs, [ii] antibody-induced cross-linking of PSMA molecules results in a time-dependent partitioning into another DRMs type, namely Triton X-100-DRMs, and [iii] concomitant with its association with Triton-X-100-DRMs internalization of PSMA occurs along tubulin filaments. In a previous work (Colombatti et al. (2009) PLoS One 4: e4608) we demonstrated that the small GTPases RAS and RAC1 and the MAPKs p38 and ERK1/2 are activated during antibody cross-linking. As downstream effects of this activation we observed a strong induction of NF-kB associated with an increased expression of IL-6 and CCL5 genes and that IL-6 and CCL5 enhanced the proliferative potential of LNCaP cells synergistically. These observations together with findings reported here hypothesize a fundamental role of DRMs during activation of PSMA as platforms for trafficking, endocytosis and signalling. Understanding these mechanisms constitutes an essential prerequisite for utilization of PSMA as a therapeutically suitable target in prostate cancer. PMID:23840421

Application of Micro-cloud point extraction for spectrophotometric determination of Malachite green, Crystal violet and Rhodamine B in aqueous samples

NASA Astrophysics Data System (ADS)

Ghasemi, Elham; Kaykhaii, Massoud

2016-07-01

A novel, green, simple and fast method was developed for spectrophotometric determination of Malachite green, Crystal violet, and Rhodamine B in water samples based on Micro-cloud Point extraction (MCPE) at room temperature. This is the first report on the application of MCPE on dyes. In this method, to reach the cloud point at room temperature, the MCPE procedure was carried out in brine using Triton X-114 as a non-ionic surfactant. The factors influencing the extraction efficiency were investigated and optimized. Under the optimized condition, calibration curves were found to be linear in the concentration range of 0.06-0.60 mg/L, 0.10-0.80 mg/L, and 0.03-0.30 mg/L with the enrichment factors of 29.26, 85.47 and 28.36, respectively for Malachite green, Crystal violet, and Rhodamine B. Limit of detections were between 2.2 and 5.1 μg/L.

Application of Micro-cloud point extraction for spectrophotometric determination of Malachite green, Crystal violet and Rhodamine B in aqueous samples.

PubMed

Ghasemi, Elham; Kaykhaii, Massoud

2016-07-05

A novel, green, simple and fast method was developed for spectrophotometric determination of Malachite green, Crystal violet, and Rhodamine B in water samples based on Micro-cloud Point extraction (MCPE) at room temperature. This is the first report on the application of MCPE on dyes. In this method, to reach the cloud point at room temperature, the MCPE procedure was carried out in brine using Triton X-114 as a non-ionic surfactant. The factors influencing the extraction efficiency were investigated and optimized. Under the optimized condition, calibration curves were found to be linear in the concentration range of 0.06-0.60mg/L, 0.10-0.80mg/L, and 0.03-0.30mg/L with the enrichment factors of 29.26, 85.47 and 28.36, respectively for Malachite green, Crystal violet, and Rhodamine B. Limit of detections were between 2.2 and 5.1μg/L. Copyright © 2016 Elsevier B.V. All rights reserved.

Anisotropy Changes of a Fluorescent Probe during the Micellar Growth and Clouding of a Nonionic Detergent.

PubMed

Komaromy-Hiller; von Wandruszka R

1996-01-15

The effects of temperature and Triton X-114 (TX-114) concentration on the fluorescence anisotropy of perylene were investigated before and after detergent clouding. The measured anisotropy values were used to estimate the microviscosity of the micellar interior. In the lower detergent concentration range, an anisotropy maximum was observed at the critical micelle concentration (CMC), while the values decreased in the range immediately above the CMC. This was ascribed to the micellar volume increase, which, in the case of TX-114, was not accompanied by a more ordered internal environment. A gradual decrease of anisotropy and microviscosity with increasing temperature below the cloud point was observed. At the cloud point, no abrupt changes were found to occur. Compared to detergents with more flexible hydrophobic moieties, TX-114 micelles have a relatively ordered micellar interior indicated by the microviscosity and calculated fusion energy values. In the separated micellar phase formed after clouding, the probe anisotropy increased as water was eliminated at higher temperatures.

A green surfactant-assisted synthesis of hierarchical TS-1 zeolites with excellent catalytic properties for oxidative desulfurization.

PubMed

Du, Shuting; Li, Fen; Sun, Qiming; Wang, Ning; Jia, Mingjun; Yu, Jihong

2016-02-25

Hierarchical TS-1 zeolites with uniform intracrystalline mesopores have been successfully synthesized through the hydrothermal method by using the green and cheap surfactant Triton X-100 as the mesoporous template. The resultant materials exhibit remarkably enhanced catalytic activity in oxidative desulfurization reactions compared to the conventional TS-1 zeolite.

Cloud point extraction-flame atomic absorption spectrometry for pre-concentration and determination of trace amounts of silver ions in water samples.

PubMed

Yang, Xiupei; Jia, Zhihui; Yang, Xiaocui; Li, Gu; Liao, Xiangjun

2017-03-01

A cloud point extraction (CPE) method was used as a pre-concentration strategy prior to the determination of trace levels of silver in water by flame atomic absorption spectrometry (FAAS) The pre-concentration is based on the clouding phenomena of non-ionic surfactant, triton X-114, with Ag (I)/diethyldithiocarbamate (DDTC) complexes in which the latter is soluble in a micellar phase composed by the former. When the temperature increases above its cloud point, the Ag (I)/DDTC complexes are extracted into the surfactant-rich phase. The factors affecting the extraction efficiency including pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time were investigated and optimized. Under the optimal experimental conditions, no interference was observed for the determination of 100 ng·mL -1 Ag + in the presence of various cations below their maximum concentrations allowed in this method, for instance, 50 μg·mL -1 for both Zn 2+ and Cu 2+ , 80 μg·mL -1 for Pb 2+ , 1000 μg·mL -1 for Mn 2+ , and 100 μg·mL -1 for both Cd 2+ and Ni 2+ . The calibration curve was linear in the range of 1-500 ng·mL -1 with a limit of detection (LOD) at 0.3 ng·mL -1 . The developed method was successfully applied for the determination of trace levels of silver in water samples such as river water and tap water.

Cold column trapping-cloud point extraction coupled to high performance liquid chromatography for preconcentration and determination of curcumin in human urine.

PubMed

Rahimi, Marzieh; Hashemi, Payman; Nazari, Fariba

2014-05-15

A cold column trapping-cloud point extraction (CCT-CPE) method coupled to high performance liquid chromatography (HPLC) was developed for preconcentration and determination of curcumin in human urine. A nonionic surfactant, Triton X-100, was used as the extraction medium. In the proposed method, a low surfactant concentration of 0.4% v/v and a short heating time of only 2min at 70°C were sufficient for quantitative extraction of the analyte. For the separation of the extraction phase, the resulted cloudy solution was passed through a packed trapping column that was cooled to 0 °C. The temperature of the CCT column was then increased to 25°C and the surfactant rich phase was desorbed with 400μL ethanol to be directly injected into HPLC for the analysis. The effects of different variables such as pH, surfactant concentration, cloud point temperature and time were investigated and optimum conditions were established by a central composite design (response surface) method. A limit of detection of 0.066mgL(-1) curcumin and a linear range of 0.22-100mgL(-1) with a determination coefficient of 0.9998 were obtained for the method. The average recovery and relative standard deviation for six replicated analysis were 101.0% and 2.77%, respectively. The CCT-CPE technique was faster than a conventional CPE method requiring a lower concentration of the surfactant and lower temperatures with no need for the centrifugation. The proposed method was successfully applied to the analysis of curcumin in human urine samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Improving electrokinetic microdevice stability by controlling electrolysis bubbles.

PubMed

Lee, Hwi Yong; Barber, Cedrick; Minerick, Adrienne R

2014-07-01

The voltage-operating window for many electrokinetic microdevices is limited by electrolysis gas bubbles that destabilize microfluidic system causing noise and irreproducible responses above ∼3 V DC and less than ∼1 kHz AC at 3 Vpp. Surfactant additives, SDS and Triton X-100, and an integrated semipermeable SnakeSkin® membrane were employed to control and assess electrolysis bubbles from platinum electrodes in a 180 by 70 μm, 10 mm long microchannel. Stabilized current responses at 100 V DC were observed with surfactant additives or SnakeSkin® barriers. Electrolysis bubble behaviors, visualized via video microscopy at the electrode surface and in the microchannels, were found to be influenced by surfactant function and SnakeSkin® barriers. Both SDS and Triton X-100 surfactants promoted smaller bubble diameters and faster bubble detachment from electrode surfaces via increasing gas solubility. In contrast, SnakeSkin® membranes enhanced natural convection and blocked bubbles from entering the microchannels and thus reduced current disturbances in the electric field. This data illustrated that electrode surface behaviors had substantially greater impacts on current stability than microbubbles within microchannels. Thus, physically blocking bubbles from microchannels is less effective than electrode functionalization approaches to stabilize electrokinetic microfluidic systems. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photophysical properties of C60 colloids suspended in water with Triton X-100 surfactant: excited-state properties with femtosecond resolution.

PubMed

Clements, Andrew F; Haley, Joy E; Urbas, Augustine M; Kost, Alan; Rauh, R David; Bertone, Jane F; Wang, Fei; Wiers, Brian M; Gao, De; Stefanik, Todd S; Mott, Andrew G; Mackie, David M

2009-06-11

We examine the photophysics of a colloidal suspension of C(60) particles in a micellar solution of Triton X-100 and water, prepared via a new synthesis which allows high-concentration suspensions. The particle sizes are characterized by transmission electron microscopy and dynamic light scattering and found to be somewhat polydisperse in the range of 10-100 nm. The suspension is characterized optically by UV-vis spectroscopy, femtosecond transient absorption spectroscopy, laser flash photolysis, and z-scan. The ground-state absorbance spectrum shows a broad absorbance feature centered near 450 nm which is indicative of colloidal C(60). The transient absorption dynamics, presented for the first time with femtosecond resolution, are very similar to that of thin films of C(60) and indicate a strong quenching of the singlet excited state on short time scales and evidence of little intersystem crossing to a triplet excited state. Laser flash photolysis reveals that a triplet excited-state absorption spectrum, which is essentially identical in shape to that of molecular C(60) solutions, does indeed arise, but with much lower magnitude and somewhat shorter lifetime. Z-scan analysis confirms that the optical response of this material is dominated by nonlinear scattering.

Electrophoretic characterization of the Mammalian nuclear matrix proteome, nuclear envelope, nucleoli and covalently bound ADP-ribose polymers: potential applications to cancer.

PubMed

Aranda, Xavier G; Racho, Ronald G; Pacheco-Rodríguez, Gustavo; Alvarez-González, Rafael

2014-01-01

Nucleic acid metabolism is biochemically compartmentalized to the nucleus. Thus, it is necessary to define the proteome of the various macromolecular structures within this organelle. We isolated the nuclear matrix (NM) fraction from rat liver by sequential centrifugation steps at 13,000 rpm, staggered between endogenous nuclease treatment for 2 h at 37°C, followed by high-salt (H.S.; 2.0 M NaCl) and non-ionic detergent extractions (0.1%- or 1.0% Triton X-100) to eliminate the bulk of chromosomal DNA/RNA, histone proteins and the nuclear envelope (NE). Integrity of the NM and NE structures was confirmed by electron microscopy. Next, we analyzed the NM proteome on a 20% polyacrylamide gel using the PhastSystem. We observed the absence of histone proteins and the characteristic presence of the lamins by Coomassie blue staining. By contrast, upon silver staining, following electrophoretic separation with a Tris-Borate-EDTA buffer, we observed the NM-associated nucleic RNA and protein-free ADP-ribose polymers. While polymers are found in much lower concentration than RNA in NM, they were purified by affinity chromatography on boronate resin prior to electrophoresis. We observed the electrophoretic resolution of free ADP-ribose chains (5-25 units) by silver staining. The significance of our observations to cancer studies and carcinogenesis is discussed. Copyright© 2014, International Institute of Anticancer Research (Dr. John G. Delinasios), All rights reserved.

Cloning and characterization of thermo-alkalistable and surfactant stable endoglucanase from Puga hot spring metagenome of Ladakh (J&K).

PubMed

Gupta, Puneet; Mishra, Arjun K; Vakhlu, Jyoti

2017-10-01

A thermo-alkalistable and surfactant stable endoglucanase (PHS) gene consisting of 554 amino acids was identified from metagenomic library of Puga hot spring using functional screening. PHS gene was overexpressed and purified to homogeneity using affinity chromatography The purified PHS protein presented a single band of 60kDa on the SDS-PAGE gel and zymogram. The recombinant PHS exhibited activity over a broad range of pH and temperature with optima at pH 8.0 and 65°C, respectively and having optimum stability at 60°C and pH 8.0, respectively. The recombinant PHS showed highest substrate specificity using CMC (218.4U/mg) as compared with Barley β-glucan (89.2U/mg) and Avicel (0.8U/mg). The K m and V max of recombinant PHS for CMC were 3.85mg/ml and 370.37μmolmin -1 mg -1 , respectively. The activity of the recombinant PHS was enhanced by treatment with 10mM non-ionic detergents such as Tween 20, Tween 40, Tween 80, Triton X- 100 and PEG and was inhibited by CTAB, SDS. Its functionality was stable in the presence of Fe 3+ but inhibited by Cu 2+ , Hg 2+ , Mn 2+ and Zn 2+ . These properties make PHS endoglucanase a potential candidate for use in laundry, textile,paper and pulp industries. Copyright © 2017 Elsevier B.V. All rights reserved.

Insolubility and redistribution of GPI-anchored proteins at the cell surface after detergent treatment.

PubMed Central

Mayor, S; Maxfield, F R

1995-01-01

A diverse set of cell surface eukaryotic proteins including receptors, enzymes, and adhesion molecules have a glycosylphosphoinositol-lipid (GPI) modification at the carboxy-terminal end that serves as their sole means of membrane anchoring. These GPI-anchored proteins are poorly solubilized in nonionic detergent such as Triton X-100. In addition these detergent-insoluble complexes from plasma membranes are significantly enriched in several cytoplasmic proteins including nonreceptor-type tyrosine kinases and caveolin/VIP-21, a component of the striated coat of caveolae. These observations have suggested that the detergent-insoluble complexes represent purified caveolar membrane preparations. However, we have recently shown by immunofluorescence and electron microscopy that GPI-anchored proteins are diffusely distributed at the cell surface but may be enriched in caveolae only after cross-linking. Although caveolae occupy only a small fraction of the cell surface (< 4%), almost all of the GPI-anchored protein at the cell surface becomes incorporated into detergent-insoluble low-density complexes. In this paper we show that upon detergent treatment the GPI-anchored proteins are redistributed into a significantly more clustered distribution in the remaining membranous structures. These results show that GPI-anchored proteins are intrinsically detergent-insoluble in the milieu of the plasma membrane, and their co-purification with caveolin is not reflective of their native distribution. These results also indicate that the association of caveolae, GPI-anchored proteins, and signalling proteins must be critically re-examined. Images PMID:7579703

Sodium 4-phenylbutyrate ameliorates the effects of cataract-causing mutant gammaD-crystallin in cultured cells.

PubMed

Gong, Bo; Zhang, Li-Yun; Lam, Dennis Shun-Chiu; Pang, Chi-Pui; Yam, Gary Hin-Fai

2010-06-04

gammaD-Crystallin (CRYGD) is a major structural lens crystallin and its mutations result in congenital cataract formation. In this study, we attempted to correct the altered protein features of G165fsX8 CRYGD protein with small chemical molecules. Recombinant FLAG-tagged mutants (R15C, R15S, P24T, R61C, and G165fsX8) of CRYGD were expressed in COS-7 cells and treated with small chemical molecules with reported protein chaperoning properties (sodium 4-phenylbutyrate [4-PBA], trimethylamine N-oxide [TMAO], and glycerol and DMSO [DMSO]). Protein solubility in 0.5% Triton X-100 and subcellular distribution was examined by western blotting and immunofluorescence, respectively. Apoptosis was assayed as the percentage of fragmented nuclei in transfected cells. Expression of heat-shock proteins (Hsp70 and Hsp90) was examined by reverse transcription-polymerase chain reaction analysis. Unlike WT and most mutants (R15C, R15S, P24T, and R61C) of CRYGD, G165fsX8 CRYGD was significantly insoluble in 0.5% Triton X-100. This insolubility was alleviated by dose-dependent 4-PBA treatment. The treatment relieved the mislocalization of G165fsX8 CRYGD from the nuclear envelope. Also, 4-PBA treatment reduced cell apoptosis and caused an upregulation of Hsp70. 4-PBA treatment reduced the defective phenotype of mutant G165fsX8 CRYGD and rescued the affected cells from apoptosis. This could be a potential treatment for lens structural protein and prevent lens opacity in cataract formation.

The specificity of binding of growth hormone and prolactin to purified plasma membranes from pregnant-rabbit liver.

PubMed Central

Webb, C F; Cadman, H F; Wallis, M

1986-01-01

The binding of 125I-labelled human growth hormone (hGH) to a purified plasma membrane preparation from the liver of pregnant rabbit, and to receptors solubilized from this fraction with Triton X-100, was dependent on time, temperature, the cations used and the receptor concentration. Solubilization did not affect the binding properties of the receptors at low concentrations of Triton X-100. Some somatogenic hormones, such as bovine GH, and some lactogenic hormones, such as ovine prolactin, displaced 125I-labelled hGH from purified plasma membranes and solubilized receptor preparations, but GHs and prolactins from various other species were rather ineffective. The results indicate that although there are binding sites for hGH in these pregnant rabbit liver membranes, few of these are specifically somatogenic or lactogenic. The binding properties of the purified plasma membranes are similar to those of a microsomal preparation studied previously, suggesting that the complex nature of the binding of hGH is not due to the heterogeneity of cellular membranes used to study binding, but is a property of the receptors associated with plasma membranes. PMID:3790086

[Thermal stability of rhodopsins and opsins in warm- and cold-blooded vertebrates].

PubMed

Berman, A L; Suvorov, S A; Parnova, R G; Gracheva, O A; Rychkova, M P

1981-01-01

Thermal stability of rhodopsins and opsins has been studied in endothermic (sheep, cattle, pig, rat) and ectothermic (frog) animals under two different conditions -- in the intact photoreceptor membranes (PM) and after substitution of the lipid surrounding of rhodopsins by molecules of a detergent Triton X-100. Lipid composition of PM in these animals was also studied, as well as the effect of proteases (pronase and papaine) upon thermal stability of rhodopsins in PM and in 1% Triton X-100 solutions. The thermal resistance of rhodopsins in PM was found to vary in the animals used to a great extent. The maximal differences in thermal stability of rhodopsins in ecto- and endothermic animals were due to the properties of photoreceptor protein itself, whereas in ectothermic animals they resulted mainly from differences in the lipid composition of PM. PM of endothermic animals differ from those of ectothermic ones by a lower content of polyenoic fatty acids and by a higher amount of phosphatidyl ethanolamine. The thermal stability of rhodopsins is not due to rhodopsin molecule as a whole, and depends mainly on its part which is directly bound to 11-cis retinal, located in hydrophobic region of PM and inaccessible to protease attack.

Molecular size of the gamma-aminobutyric acidA receptor purified from mammalian cerebral cortex.

PubMed

Mamalaki, C; Barnard, E A; Stephenson, F A

1989-01-01

The hydrodynamic behaviour of both the soluble and purified gamma-aminobutyric acidA (GABAA) receptor of bovine or rat cerebral cortex has been investigated in solution in Triton X-100 or in 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulphonate (CHAPS). In all the hydrodynamic separations made, it was found that the binding activities for GABA, benzodiazepine, and (where detectable) t-butylbicyclophosphorothionate comigrated. Conditions were established for gel exclusion chromatography and for sucrose density gradient velocity sedimentation that maintain the GABAA receptor in a nonaggregated form. Using these conditions, the molecular weight of the bovine GABAA receptor in the above-mentioned detergents was calculated using the H2O/2H2O method. A value of Mr 230,000-240,000 was calculated for the bovine pure GABAA receptor purified in sodium deoxycholate/Triton X-100 media. A value of Mr 284,000-290,000 was calculated for the nonaggregated bovine or rat cortex receptor in CHAPS, but the Stokes radius is smaller in the latter than in the former medium and the detergent binding in CHAPS is underestimated. Thus the deduced Mr, 240,000, is the best estimate by this method.

Geographic Distribution of N2, CH4, CO2, and H2O Ices on Triton from Near-IR Spectroscopic Monitoring

NASA Astrophysics Data System (ADS)

Grundy, W. M.; Young, L. A.; Young, E. F.; Buie, M. W.; Spencer, J. R.

2004-11-01

We present new 0.8 to 2.4 μ m spectral observations of Neptune's satellite Triton, obtained at IRTF\\slash SpeX between 2001 and 2004 as part of an ongoing search for time-variable phenomena associated with Triton's seasonal volatile transport processes, and also perhaps with reported shorter-term "reddening" events. The ability to detect spectral changes on these time scales depends critically on accurate characterization of any cyclic variations resulting from Triton's 5.877 day rotation period. We will report on our observations of periodic variations of Triton's near-IR absorption bands of N2, CH4, and H2O ices, but not of CO2 ice, in this initial stage of our Triton monitoring program. The observed variations (or lack thereof) give an indication of how these four ice species are distributed in longitude. The most heterogeneously distributed ice is N2, which shows nearly twice as much absorption on Triton's Neptune-facing hemisphere as on the anti-Neptune hemisphere. Comparison with Voyager-era, visual wavelength imaging of Triton's surface suggest that the observed N2 ice is concentrated on low-latitude regions of Triton's polar cap, which are predominantly located on the Neptune-facing hemisphere. Non-volatile H2O ice seems to be slightly concentrated on Triton's leading hemisphere. Despite being highly diluted in N2 ice, the longitudinal distribution of Triton's CH4 ice differs from that of Triton's N2 ice, being slightly concentrated on Triton's trailing hemisphere. Triton's CO2 ice shows the least longitudinal variation, suggesting that it is either very uniformly distributed or that it is confined to high latitudes. This work was supported by NASA's Planetary Astronomy and Planetary Geology &\\ Geophysics programs, and by NSF's Planetary Astronomy program. \\hangindent=0.3truein Grundy, W.M., and L.A. Young (2004) Near infrared spectral monitoring of Triton with IRTF\\slash SpeX I: Establishing a baseline. Icarus (in press).

A fluorescent molecular sensor for pH windows in traditional and polymeric biocompatible micelles: comicellization of anionic species to shift and reshape the ON window.

PubMed

Cavallaro, Gennara; Giammona, Gaetano; Pasotti, Luca; Pallavicini, Piersandro

2011-09-12

A new approach is presented to obtain fluorescent sensors for pH windows that work in water and under biomimetic conditions. A single molecule that features all-covalently linked components is used, thus making it capable of working as a fluorescent sensor with an OFF/ON/OFF response to pH value. The components are a tertiary amine, a pyridine, and a fluorophore (pyrene). The forms with both protonated bases or both neutral bases quench the pyrene fluorescence, whereas the form with the neutral pyridine and protonated amine groups is fluorescent. The molecular sensor is also equipped with a long alkyl chain to make it highly hydrophobic in all its protonated and unprotonated forms, that is, either when neutral or charged. Accordingly, it can be confined at any pH value either in traditional (i.e., low-molecular-weight) nonionic surfactant micelles or inside polymeric, biocompatible micellar containers. Relevant for future applications in vivo, thanks to its strong hydrophobicity, no leakage of the molecular sensor is observed from the polymeric biocompatible micelles. Due to the proximity of the pyridine and amine functions in the molecular structure and the poor hydration inside the micelles, the observed pK(a) values are low so that the ON window is positioned at very low pH values. However, the window can be shifted to biologically relevant values by comicellization of anionic species. In particular, in the micelles of the nonionic surfactant TritonX-100, a shift of the ON window to pH 4-6 is obtained by addition of the anionic sodium dodecyl sulphate surfactant, whose negative charge promotes the stability of the protonated forms of the pyridine and amine fragments. In the case of the polymeric micelles, we introduce the use of the amphiphilic polystyrene sulfonate anionic polyelectrolyte, the comicellization of which induces a shift and sharpening of the ON window that is centered at pH 4. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Innovative sponge-based moving bed-osmotic membrane bioreactor hybrid system using a new class of draw solution for municipal wastewater treatment.

PubMed

Nguyen, Nguyen Cong; Chen, Shiao-Shing; Nguyen, Hau Thi; Ray, Saikat Sinha; Ngo, Huu Hao; Guo, Wenshan; Lin, Po-Hsun

2016-03-15

For the first time, an innovative concept of combining sponge-based moving bed (SMB) and an osmotic membrane bioreactor (OsMBR), known as the SMB-OsMBR hybrid system, were investigated using Triton X-114 surfactant coupled with MgCl2 salt as the draw solution. Compared to traditional activated sludge OsMBR, the SMB-OsMBR system was able to remove more nutrients due to the thick-biofilm layer on sponge carriers. Subsequently less membrane fouling was observed during the wastewater treatment process. A water flux of 11.38 L/(m(2) h) and a negligible reverse salt flux were documented when deionized water served as the feed solution and a mixture of 1.5 M MgCl2 and 1.5 mM Triton X-114 was used as the draw solution. The SMB-OsMBR hybrid system indicated that a stable water flux of 10.5 L/(m(2) h) and low salt accumulation were achieved in a 90-day operation. Moreover, the nutrient removal efficiency of the proposed system was close to 100%, confirming the effectiveness of simultaneous nitrification and denitrification in the biofilm layer on sponge carriers. The overall performance of the SMB-OsMBR hybrid system using MgCl2 coupled with Triton X-114 as the draw solution demonstrates its potential application in wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ion-pair cloud-point extraction: a new method for the determination of water-soluble vitamins in plasma and urine.

PubMed

Heydari, Rouhollah; Elyasi, Najmeh S

2014-10-01

A novel, simple, and effective ion-pair cloud-point extraction coupled with a gradient high-performance liquid chromatography method was developed for determination of thiamine (vitamin B1 ), niacinamide (vitamin B3 ), pyridoxine (vitamin B6 ), and riboflavin (vitamin B2 ) in plasma and urine samples. The extraction and separation of vitamins were achieved based on an ion-pair formation approach between these ionizable analytes and 1-heptanesulfonic acid sodium salt as an ion-pairing agent. Influential variables on the ion-pair cloud-point extraction efficiency, such as the ion-pairing agent concentration, ionic strength, pH, volume of Triton X-100, extraction temperature, and incubation time have been fully evaluated and optimized. Water-soluble vitamins were successfully extracted by 1-heptanesulfonic acid sodium salt (0.2% w/v) as ion-pairing agent with Triton X-100 (4% w/v) as surfactant phase at 50°C for 10 min. The calibration curves showed good linearity (r(2) > 0.9916) and precision in the concentration ranges of 1-50 μg/mL for thiamine and niacinamide, 5-100 μg/mL for pyridoxine, and 0.5-20 μg/mL for riboflavin. The recoveries were in the range of 78.0-88.0% with relative standard deviations ranging from 6.2 to 8.2%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of sodium hypochlorite irrigation with or without surfactants on the bond strength of an epoxy-based sealer to dentin.

PubMed

Guneser, Mehmet Burak; Arslan, Dilara; Dincer, Asiye Nur; Er, Gamze

2017-05-01

This study evaluated the effect of sodium hypochlorite (NaOCl) irrigation with or without surfactants on the bond strength of an epoxy-based sealer to the root canal dentin. Eighty decoronated single-rooted human mandibular premolars were instrumented using the rotary system. The roots were subsequently rinsed with 5 ml 17 % EDTA for 1 min and then randomly divided into 3 test groups (n = 20) and 1 control group (n = 20) according to the type of irrigation with experimental 5 % NaOCl (Wizard, RehberKimya, Istanbul, Turkey) solutions: Group 1: NaOCl-0.1 % benzalkonium chloride; Group 2: NaOCl-0.1 % Tween 80; Group 3: NaOCl-0.1 % Triton X-100; control group: NaOCl without any surfactants. Five samples from each group were prepared for scanning electron microscopy to examine the surface of root canal dentin. The 15 samples remaining in each group were obturated with gutta-percha and AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany) using the cold lateral compaction technique. A push-out test was used to measure the bond strength between the sealer and root canal dentin. Data were analyzed using two-way analysis of variance and Tukey's post hoc tests (P = 0.05). The NaOCl-0.1 % Triton X-100 group demonstrated the highest mean bond-strength values in all root thirds among the groups (P < 0.05). However, the bond strength of the sealer in the NaOCl-0.1 % benzalkonium chloride and NaOCl-0.1 % Tween 80 groups did not differ from that in the control group (P > 0.05). Additionally, the bond-strength values decreased in the corono-apical direction for all groups (P < 0.05). NaOCl solution with Triton X-100 can provide higher bond strength of the epoxy resin-based sealer to root dentin compared to NaOCl solution wiithout any surfactant. The bond strength of sealer to dentin can be improved by the addition of the surfactants to NaOCl solution.

Removal of detergents from proteins and peptides in a spin-column format.

PubMed

Antharavally, Babu S

2012-08-01

To enable downstream analysis, it is critical to remove unbound detergents from protein and peptide samples. This unit describes the use of a high-performance resin that offers exceptional detergent removal for proteins and peptides. The easy-to-use spin format significantly improves results over the standard drip column and batch methodologies, with >95% removal of 1% to 5% detergents, including SDS, sodium deoxycholate, CHAPS, Triton X-100, Triton X-114, NP-40, Brij-35, octyl glucoside, octyl thioglucoside, and lauryl maltoside, with high recovery of proteins and peptides. Detergent removal efficiency is evaluated using colorimetric methods and mass spectrometry (MS). BSA tryptic peptides have been successfully analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and matrix-assisted laser desorption/ionization (MALDI)-MS for identification of protein, following detergent removal using the resin. Advantages of this method include speed (less than 15 min), efficient detergent removal, and high recovery of proteins and peptides. © 2012 by John Wiley & Sons, Inc.

Determination of sperm acrosin activity in the arctic fox (Alopex lagopus L.)--using method developed for human spermatozoa.

PubMed

Stasiak, K; Janicki, B; Glogowski, J

2012-01-01

The aim of the study was to adapt a method to determine acrosin activity of human spermatozoa to arctic fox (Alopex lagopus L.) spermatozoa. We modified this method by reducing sperm count per sample from 1 divided by 10 x 10(6) to 25 divided by 200 x 10(3), incubation time from 180 minutes to 60 minutes, and Triton X-100 concentration in the reaction mixture from 0.01% to 0.005% per 100 cm3. It has also confirmed that arctic fox seminal plasma is rich in proteinases and their inhibitors. To completely abolish the inhibitory effect of seminal plasma on acrosin activity it is recommended to wash the spermatozoa four times. Benzamidine served an inhibitor of acrosin activity.

Materials Engineering and Scale Up of Fluid Phase Chemical Hydrogen Storage for Automotive Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westman, Matthew P.; Chun, Jaehun; Choi, Young Joon

Among candidates for chemical hydrogen storage in PEM fuel cell automotive applications, ammonia borane (AB, NH3BH3) is considered to be one of the most promising materials due to its high hydrogen content of 14-16 wt% below 200°C and high volumetric density. In our previous paper, we selected AB in silicone oil as a role model for a slurry hydrogen storage system. Materials engineering properties were optimized by increasing solid loading by using an ultra-sonic process. In this paper, we proceeded to scale up to liter size batches with solid loadings up to 50 wt% (8 wt% H2) with dynamic viscositiesmore » less than 1000cP at 25°C. The use of a non-ionic surfactant, Triton X-15, shows significant promise in controlling the level of foaming produced during the thermal dehydrogenation of the AB. Through the development of new and efficient processing techniques and the ability to adequately control the foaming, stable homogenous slurries of high solid loading have been demonstrated as a viable hydrogen delivery source.« less

Nanoparticles of spinel and perovskite ferromagnets and prospects for their application in medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belous, A. G., E-mail: belous@ionc.kar.net, E-mail: solopan@ukr.net, E-mail: yelenicho@ukr.net; Solopan, S. O., E-mail: belous@ionc.kar.net, E-mail: solopan@ukr.net, E-mail: yelenicho@ukr.net; Yelenich, O. V., E-mail: belous@ionc.kar.net, E-mail: solopan@ukr.net, E-mail: yelenicho@ukr.net

In this work, nanoparticles of La{sub 0.75}Sr{sub 0.25}MnO{sub 3} compounds with perovskite structure and AFe{sub 2}O{sub 4} (A = Mn, Fe, Co, Ni, Zn) with spinel structure have been synthesized by precipitation from diethylene glycol and microemulsion using Triton X-100 surfactant. Comparative X-ray diffraction and magnetic studies of the synthesized nanoparticles have been carried out. Magnetic fluids prepared from synthesized nanopowders have been characterized by calorimetric measurements of specific loss power (SLP)

Do Prostate Cancer Exosomes Generate a Field Effect Leading to Tumor Multifocality

DTIC Science & Technology

2016-04-01

ELEMENT NUMBER 6. AUTHOR(S) Marco Bisoffi 5d. PROJECT NUMBER 5e. TASK NUMBER E-Mail: bisoffi@chapman.edu 5f. WORK UNIT NUMBER 7... Sigma St. Louis MO. Plasmids were propagated in E. coli strain JM109 grown in LB broth containing 100ug/mL ampicillin and purified using spin column...buffer: 25 mM Tris, 8 mM MgCl2, 1 mM DTT, 15% glycerol, 1% TritonX-100, protease inhibitor cocktail ( Sigma St. Louis MO). Insoluble cell material was

The Thermal Structure of Triton's Atmosphere: Results from the 1993 and 1995 Occultations

NASA Astrophysics Data System (ADS)

Olkin, C. B.; Elliot, J. L.; Hammel, H. B.; Cooray, A. R.; McDonald, S. W.; Foust, J. A.; Bosh, A. S.; Buie, M. W.; Millis, R. L.; Wasserman, L. H.; Dunham, E. W.; Young, L. A.; Howell, R. R.; Hubbard, W. B.; Hill, R.; Marcialis, R. L.; McDonald, J. S.; Rank, D. M.; Holbrook, J. C.; Reitsema, H. J.

1997-09-01

This paper presents new results about Triton's atmospheric structure from the analysis of all ground-based stellar occultation data recorded to date, including one single-chord occultation recorded on 1993 July 10 and nine occultation lightcurves from the double-star event on 1995 August 14. These stellar occultation observations made both in the visible and in the infrared have good spatial coverage of Triton, including the first Triton central-flash observations, and are the first data to probe the altitude level 20-100 km on Triton. The small-planet lightcurve model of J. L. Elliot and L. A. Young (1992,Astron. J.103,991-1015) was generalized to include stellar flux refracted by the far limb, and then fitted to the data. Values of the pressure, derived from separate immersion and emersion chords, show no significant trends with latitude, indicating that Triton's atmosphere is spherically symmetric at ∼50-km altitude to within the error of the measurements; however, asymmetry observed in the central flash indicates the atmosphere is not homogeneous at the lowest levels probed (∼20-km altitude). From the average of the 1995 occultation data, the equivalent-isothermal temperature of the atmosphere is 47 ± 1 K and the atmospheric pressure at 1400-km radius (∼50-km altitude) is 1.4 ± 0.1 μbar. Both of these are not consistent with a model based on Voyager UVS and RSS observations in 1989 (D. F. Strobel, X. Zhu, M. E. Summers, and M. H. Stevens, 1996,Icarus120,266-289). The atmospheric temperature from the occultation is 5 K colder than that predicted by the model and the observed pressure is a factor of 1.8 greater than the model. In our opinion, the disagreement in temperature and pressure is probably due to modeling problems at the microbar level, since measurements at this level have not previously been made. Alternatively, the difference could be due to seasonal change in Triton's atmospheric structure.

TRITON HYPERLIPEMIA IN DOGS

PubMed Central

Scanu, Angelo; Oriente, Pasquale; Szajewski, Janusz M.; McCormack, Lawrence J.; Page, Irvine H.

1961-01-01

Fourteen dogs, fed a regular diet and given 250 mg/kg of triton (a non-ionic surface-active agent) intravenously every 4th day, exhibited a progressively severe hyperlipemia. Serum triglycerides were the first to increase. Cholesterol, mostly in the free form, and phospholipids showed elevation only at a later stage and increased at almost identical rates. The plasma-free fatty acid concentration was from 2 to 3 times above normal. With establishment of sustained hyperlipemia, there was reduction, followed by total disappearance, of the high density D 1.063 to 1.21 lipoprotein. Most of the cholesterol and phospholipids (70 to 75 per cent of the total) were found in the D 1.006 to 1.063 lipoprotein class, the remainder in the D < 1.006 class. Triglycerides were almost evenly distributed between these two classes. The concentration of the serum lipoprotein proteins was within normal limits. All of the animals died within from 4 to 5 months after receiving the first injection of triton. Autopsy findings consistently showed: (a) numerous lipidladen macrophages in the liver, spleen, and lymph nodes; (b) significant depletion of all fat stores; (c) presence of lipids, either free or engulfed in macrophages (foam cells), in the subintima of the coronary arteries, aorta, and pulmonary arteries, indicating an early stage of atherosclerosis. Concurrent daily administration of heparin (5 mg per kilogram of body weight) did not substantially change the course of the disease. Withdrawal of triton from animals that had been receiving the detergent for from 3 to 4 months, elicited a slow return to normal of the lipid pattern. In two dogs killed when normolipemia was reestablished, all tissues were normal with the minor exception of a few hepatic macrophages still laden with sudanophilic material. It is postulated that the primary action of the injected triton was on the lipid moieties of plasma lipoproteins with formation of complexes, which, as foreign bodies, were preferentially taken up by the cells of the reticuloendothelial system. Depletion of fat stores was probably secondary to increased lipid mobilization, as an attempt by these tissues to supply energy to the parenchymal cells unable to utilize triton-bound lipids. PMID:13747053

Characterization of the class III collagen receptor, a phosphorylated, transmembrane glycoprotein expressed in nucleated human cells.

PubMed

Carter, W G; Wayner, E A

1988-03-25

We previously identified a 90-kDa cell surface glycoprotein, termed the class III collagen receptor (CRIII), that bound to collagen in affinity chromatography experiments (Wayner, E. A., and Carter, W. G. (1987) J. Cell Biol. 105, 1873-1884). Here, we utilize monoclonal antibodies to define three domains of the CRIII, hydrophobic transmembrane, phosphorylated cytoplasmic, and glycosylated extracellular. The domain designations are based on the following characteristics. (i) Differential extraction, phase partitioning with Triton X-114, and incorporation into liposomes all indicate that the CRIII is an intrinsic membrane receptor with a hydrophobic domain. After incorporation into liposomes the CRIII binds collagen. (ii) Immunofluorescence microscopy reveals that most nucleated cells express the CRIII and that after extraction with Triton X-100, the Triton-insoluble CRIII distributes in a fibrillar pattern at the cell periphery and in closed loops that partially co-distributed with vimentin. The CRIII contains phosphoserine residues which are located on a cytoplasmic domain that may interact with the cytoskeleton. (iii) The CRIII contains 25% carbohydrate in 8-10 asparagine-linked carbohydrate chains of 2800 daltons each bound to a 65-kDa core peptide in the extracellular domain. Peptide mapping with trypsin defined a glycosylated 27-kDa extracellular fragment and a phosphorylated and glycosylated 35-kDa transmembrane fragment. These data suggest a model for the CRIII that links the cytoskeleton with the extracellular matrix.

Triton X-114 based cloud point extraction: a thermoreversible approach for separation/concentration and dispersion of nanomaterials in the aqueous phase.

PubMed

Liu, Jing-fu; Liu, Rui; Yin, Yong-guang; Jiang, Gui-bin

2009-03-28

Capable of preserving the sizes and shapes of nanomaterials during the phase transferring, Triton X-114 based cloud point extraction provides a general, simple, and cost-effective route for reversible concentration/separation or dispersion of various nanomaterials in the aqueous phase.

Effect of Nonionic Surfactant Additive in PEDOT:PSS on PFO Emission Layer in Organic-Inorganic Hybrid Light-Emitting Diode.

PubMed

Cho, Seong Rae; Porte, Yoann; Kim, Yun Cheol; Myoung, Jae-Min

2018-03-21

Poly(9,9-dioctylfluorene) (PFO) has attracted significant interests owing to its versatility in electronic devices. However, changes in its optical properties caused by its various phases and the formation of oxidation defects limit the application of PFO in light-emitting diodes (LEDs). We investigated the effects of the addition of Triton X-100 (hereinafter shortened as TX) in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to induce interlayer diffusion between PEDOT:PSS and PFO to enhance the stability of the PFO phase and suppress its oxidation. Photoluminescence (PL) measurement on PFO/TX-mixed PEDOT:PSS layers revealed that, upon increasing the concentration of TX in the PEDOT:PSS layer, the β phase of PFO could be suppressed in favor of the glassy phase and the wide PL emission centered at 535 nm caused by ketone defects formed by oxidation was decreased considerably. LEDs were then fabricated using PFO as an emission layer, TX-mixed PEDOT:PSS as hole-transport layer, and zinc oxide (ZnO) nanorods as electron-transport layer. As the TX concentration reached 3 wt %, the devices exhibited dramatic increases in current densities, which were attributed to the enhanced hole injection due to TX addition, along with a shift in the dominant emission wavelength from a green electroluminescence (EL) emission centered at 518 nm to a blue EL emission centered at 448 nm. The addition of TX in PEDOT:PSS induced a better hole injection in the PFO layer, and through interlayer diffusion, stabilized the glassy phase of PFO and limited the formation of oxidation defects.

Purification and partial characterization of the major outer membrane protein of Chlamydia trachomatis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caldwell, H.D.; Kromhout, J.; Schachter, J.

1981-03-01

Elementary bodies (EB) of Chlamydia trachomatis serotypes C, E, and L2 were extrinsically radioiodinated, and whole-cell lysates of these serotypes were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Autoradiography of the polypeptide profiles identified a major surface protein with an apparent subunit molecular weight of 39,500 that was common to each C. trachomatis serotype. The abilities of nonionic (Triton X-100), dipolar ionic (Zwittergent TM-314), mild (sodium deoxycholate and sodium N-lauroyl sarcosine), and strongly anionic (SDS) detergents to extract this protein from intact EB of the L2 serotype were investigated by SDS-PAGE analysis of the soluble and insoluble fractions obtainedmore » after each detergent treatment. Only SDS readily extracted this protein from intact EB. Sarkosyl treatment selectively solubilized the majority of other EB proteins, leaving the 39,500-dalton protein associated with the Sarkosyl-insoluble fraction. Ultrastructural studies of the Sarkosyl-insoluble EB pellet showed it to consist of empty EB particles possessing an apparently intact outer membrane. No structural evidence for a peptidoglycan-like cell wall was found. Morphologically these chlamydial outer membrane complexes (COMC) resembled intact chlamydial EB outer membranes. The 39,500-dalton outer membrane protein was quantitatively extracted from COMC by treating them with 2% SDS at 60 degrees C. This protein accounted for 61% of the total COMC-associated protein, and its extraction resulted in a concomitant loss of the COMC membrane structure and morphology. The 39,500-dalton major outer membrane protein is a serogroup antigen of C. trachomatis organisms.« less

Solubilization of adenylyl cyclase from human myometrium in a alphas-coupled form.

PubMed

Bajo, Ana M; Prieto, Juan C; Valenzuela, Pedro; Martinez, Pilar; Guijarro, Luis G

2003-08-01

Adenylyl cyclase (AC) was extracted from human myometrium with either non-ionic (Lubrol-PX or Triton X-100) or zwitterionic (3-[3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, CHAPS) detergents. The soluble enzyme was stimulated by forskolin, a hydrophobic activator, in the presence of Mg2+ indicating that the catalytic subunit had not been damaged after solubilization. The enzyme was also activated by 5'-guanylyl imidodiphosphate (Gpp(NH)p) showing that the catalytic unit was not separated from stimulatory guanine nucleotide binding protein (Gs) during the extraction. Both activators showed different effects on the stimulatory efficacy and potency of AC activity solobulized with detergents. Gel filtration of Lubrol-PX and CHAPS extracts over a Sepharose CL-2B column partially resolved AC and its complexes. The chromatographic profile for Lubrol-solubilized AC presented a main peak of about 200 kDa whereas CHAPS-solubilized AC showed a dominant peak of about 1100 kDa. The heterodisperse peaks obtained revealed that the catalytic AC subunit was not separated from Gs proteins after gel filtration, and that AC could be associated with other cellular proteins. When Lubrol extract was submitted to anionic-exchange chromatography, the enzyme was purified about 7.5 fold (enzymatic activity of 48.1 pmol/min/mg of protein). The catalytic subunit was co-eluted with both AC-activating proteins Galphas large (52.2 kDa) and Galphas small (48.7 kDa). This is the first demonstration of the stable physical association of AC with both alphas subunits of G proteins in human myometrium.

Rapid amperometric detection of Escherichia coli in wastewater by measuring β-D glucuronidase activity with disposable carbon sensors.

PubMed

Rochelet, Murielle; Solanas, Sébastien; Betelli, Laetitia; Chantemesse, Benoît; Vienney, Fabienne; Hartmann, Alain

2015-09-10

An assay on the indirect amperometric quantification of the β-D-Glucuronidase (GLUase) activity was developed for the rapid and specific detection of Escherichia coli (E. coli) in complex environmental samples. The p-aminophenyl β-D-glucopyranoside (PAPG) was selected as an electrochemical substrate for GLUase measurement and the p-aminophenol (PAP) released during the enzymatic hydrolysis was monitored by cyclic voltammetry with disposable carbon screen-printed sensors. The intensity of the measured anodic peak current was proportional to the amount of GLUase, and therefore to the number of E. coli in the tested sample. Once the substrate concentration and pH values optimized, a GLUase detection limit of 10 ng mL(-1) was achieved. Using a procedure involving a filtration step of the bacteria followed by their incubation with the substrate solution containing both the nonionic detergent Triton X-100 as permeabilization agent and the culture media Luria broth to monitor the growth, filtered bacterial cells ranging from 5 × 10(4) to 10(8) UFC/membrane were detected within 3 h. The amperometric assay was applied to the determination of fecal contamination in raw and treated wastewater samples and it was successfully compared with conventional bacterial plating methods and uidA gene quantitative PCR. Owing to its ability to perform measurements in turbid media, the GLUase amperometric method is a reliable tool for the rapid and decentralized quantification of viable but also nonculturable E. coli in complex environmental samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Study of a non-diffusing radiochromic gel dosimeter for 3D radiation dose imaging

NASA Astrophysics Data System (ADS)

Marsden, Craig Michael

2000-12-01

This thesis investigates the potential of a new radiation gel dosimeter, based on nitro-blue tetrazolium (NBTZ) suspended in a gelatin mold. Unlike all Fricke based gel dosimeters this dosimeter does not suffer from diffusive loss of image stability. Images are obtained by an optical tomography method. Nitro blue tetrazolium is a common biological indicator that when irradiated in an aqueous medium undergoes reduction to a highly colored formazan, which has an absorbance maximum at 525nm. Tetrazolium is water soluble while the formazan product is insoluble. The formazan product sticks to the gelatin matrix and the dose image is maintained for three months. Methods to maximize the sensitivity of the system were evaluated. It was found that a chemical detergent, Triton X-100, in combination with sodium formate, increased the dosimeter sensitivity significantly. An initial G-value of formazan production for a dosimeter composed of 1mM NBTZ, gelatin, and water was on the order of 0.2. The addition of Triton and formate produced a G-value in excess of 5.0. The effects of NBTZ, triton, formate, and gel concentration were all investigated. All the gels provided linear dose vs. absorbance plots for doses from 0 to >100 Gy. It was determined that gel concentration had minimal if any effect on sensitivity. Sensitivity increased slightly with increasing NBTZ concentration. Triton and formate individually and together provided moderate to large increases in dosimeter sensitivity. The dosimeter described in this work can provide stable 3D radiation dose images for all modalities of radiation therapy equipment. Methods to increase sensitivity are developed and discussed.

Inhibition of nitrate transport by anti-nitrate reductase IgG fragments and the identification of plasma membrane associated nitrate reductase in roots of barley seedlings

NASA Technical Reports Server (NTRS)

Ward, M. R.; Tischner, R.; Huffaker, R. C.

1988-01-01

Membrane associated nitrate reductase (NR) was detected in plasma membrane (PM) fractions isolated by aqueous two-phase partitioning from barley (Hordeum vulgare L. var CM 72) roots. The PM associated NR was not removed by washing vesicles with 500 millimolar NaCl and 1 millimolar EDTA and represented up to 4% of the total root NR activity. PM associated NR was stimulated up to 20-fold by Triton X-100 whereas soluble NR was only increased 1.7-fold. The latency was a function of the solubilization of NR from the membrane. NR, solubilized from the PM fraction by Triton X-100 was inactivated by antiserum to Chlorella sorokiniana NR. Anti-NR immunoglobulin G fragments purified from the anti-NR serum inhibited NO3- uptake by more than 90% but had no effect on NO2- uptake. The inhibitory effect was only partially reversible; uptake recovered to 50% of the control after thorough rinsing of roots. Preimmune serum immunoglobulin G fragments inhibited NO3- uptake 36% but the effect was completely reversible by rinsing. Intact NR antiserum had no effect on NO3- uptake. The results present the possibility that NO3- uptake and NO3- reduction in the PM of barley roots may be related.

Effect of different baculovirus inactivation procedures on the integrity and immunogenicity of porcine parvovirus-like particles.

PubMed

Rueda, P; Fominaya, J; Langeveld, J P; Bruschke, C; Vela, C; Casal, J I

2000-11-22

We have demonstrated earlier the usefulness of recombinant porcine parvovirus (PPV) virus-like particles (VLPs) as an efficient recombinant vaccine for PPV. Here, we have demonstrated that preparations of PPV VLPs could be contaminated by recombinant baculoviruses. Since these baculoviruses can be a problem for the registration and safety requirements of the recombinant vaccine, we have tested different baculovirus inactivation strategies, studying simultaneously the integrity and immunogenicity of the VLPs. These methods were pasteurization, treatment with detergents and alkylation with binary ethylenimine (BEI). The structural and functional integrity of the PPV VLPs after the inactivation treatments were analyzed by electron microscopy, hemagglutination, double antibody sandwich (DAS)-ELISA and immunogenicity studies. Binary ethylenimine and Triton X-100 inactivated particles maintained all the original structural and antigenic properties. In addition, PPV VLPs were subjected to size-exclusion chromatography to analyze the presence of VP2 monomers or any other contaminant. The resulting highly purified material was used as the standard of reference to quantify PPV VLPs in order to determine the dose of vaccine by DAS-ELISA. After immunization experiments in guinea pigs, the antibody titers obtained with all the inactivation procedures were very similar. Triton X-100 treatment was selected for further testing in animals because of the speed, simplicity and safety of the overall procedure.

Raft-mediated trafficking of apical resident proteins occurs in both direct and transcytotic pathways in polarized hepatic cells: role of distinct lipid microdomains.

PubMed

Slimane, Tounsia Aït; Trugnan, Germain; Van IJzendoorn, Sven C D; Hoekstra, Dick

2003-02-01

In polarized hepatic cells, pathways and molecular principles mediating the flow of resident apical bile canalicular proteins have not yet been resolved. Herein, we have investigated apical trafficking of a glycosylphosphatidylinositol-linked and two single transmembrane domain proteins on the one hand, and two polytopic proteins on the other in polarized HepG2 cells. We demonstrate that the former arrive at the bile canalicular membrane via the indirect transcytotic pathway, whereas the polytopic proteins reach the apical membrane directly, after Golgi exit. Most importantly, cholesterol-based lipid microdomains ("rafts") are operating in either pathway, and protein sorting into such domains occurs in the biosynthetic pathway, largely in the Golgi. Interestingly, rafts involved in the direct pathway are Lubrol WX insoluble but Triton X-100 soluble, whereas rafts in the indirect pathway are both Lubrol WX and Triton X-100 insoluble. Moreover, whereas cholesterol depletion alters raft-detergent insolubility in the indirect pathway without affecting apical sorting, protein missorting occurs in the direct pathway without affecting raft insolubility. The data implicate cholesterol as a traffic direction-determining parameter in the direct apical pathway. Furthermore, raft-cargo likely distinguishing single vs. multispanning membrane anchors, rather than rafts per se (co)determine the sorting pathway.

Raft-mediated Trafficking of Apical Resident Proteins Occurs in Both Direct and Transcytotic Pathways in Polarized Hepatic Cells: Role of Distinct Lipid Microdomains

PubMed Central

Slimane, Tounsia Aït; Trugnan, Germain; van IJzendoorn, Sven C.D.; Hoekstra, Dick

2003-01-01

In polarized hepatic cells, pathways and molecular principles mediating the flow of resident apical bile canalicular proteins have not yet been resolved. Herein, we have investigated apical trafficking of a glycosylphosphatidylinositol-linked and two single transmembrane domain proteins on the one hand, and two polytopic proteins on the other in polarized HepG2 cells. We demonstrate that the former arrive at the bile canalicular membrane via the indirect transcytotic pathway, whereas the polytopic proteins reach the apical membrane directly, after Golgi exit. Most importantly, cholesterol-based lipid microdomains (“rafts”) are operating in either pathway, and protein sorting into such domains occurs in the biosynthetic pathway, largely in the Golgi. Interestingly, rafts involved in the direct pathway are Lubrol WX insoluble but Triton X-100 soluble, whereas rafts in the indirect pathway are both Lubrol WX and Triton X-100 insoluble. Moreover, whereas cholesterol depletion alters raft-detergent insolubility in the indirect pathway without affecting apical sorting, protein missorting occurs in the direct pathway without affecting raft insolubility. The data implicate cholesterol as a traffic direction-determining parameter in the direct apical pathway. Furthermore, raft-cargo likely distinguishing single vs. multispanning membrane anchors, rather than rafts per se (co)determine the sorting pathway. PMID:12589058

Solubilization of bovine corpus-luteum adenylate cyclase in lubrol-PX, triton X-100 or digitonin and the stabilizing effect of sodium fluoride present in the solubilization medium.

PubMed

Young, J L; Stansfield, D A

1978-09-01

1. Adenylate cyclase activity of the washed 600g sediment of bovine corpus-luteum homogenate was solubilized by Lubrol-PX, Triton X-100 and digitonin. Digitonin was the least destructive of NaF-stimulated activity. 2. NaF, present in the solubilization medium together with MgSO4, increased the percentage yields of soluble activity from untreated 600g sediment and 600g sediment which had been preincubated with p[NH]ppG (guanosine 5'-[betagamma-imido]triphosphate). The stabilizing influence of NaF was most marked with digitonin. However, the highest specific activities of soluble enzyme were obtained with Lubrol-PX as solubilizing agent, since digitonin solubilized more membrane protein than does Lubrol-PX, and less of the activity of the digitonin-dispersed 600g sediment was recovered in the 105000g supernatant. 3. p[NH]ppG also has a stabilizing effect when present during the solubilization, but less so than NaF. 4. Both NaF and MgSO4 alone have a stabilizing effect during solubilization. The greatest amounts of soluble activity were obtained with both agents present in the solubilization medium, there being a synergistic effect.

Solubilization of bovine corpus-luteum adenylate cyclase in lubrol-PX, triton X-100 or digitonin and the stabilizing effect of sodium fluoride present in the solubilization medium.

PubMed Central

Young, J L; Stansfield, D A

1978-01-01

1. Adenylate cyclase activity of the washed 600g sediment of bovine corpus-luteum homogenate was solubilized by Lubrol-PX, Triton X-100 and digitonin. Digitonin was the least destructive of NaF-stimulated activity. 2. NaF, present in the solubilization medium together with MgSO4, increased the percentage yields of soluble activity from untreated 600g sediment and 600g sediment which had been preincubated with p[NH]ppG (guanosine 5'-[betagamma-imido]triphosphate). The stabilizing influence of NaF was most marked with digitonin. However, the highest specific activities of soluble enzyme were obtained with Lubrol-PX as solubilizing agent, since digitonin solubilized more membrane protein than does Lubrol-PX, and less of the activity of the digitonin-dispersed 600g sediment was recovered in the 105000g supernatant. 3. p[NH]ppG also has a stabilizing effect when present during the solubilization, but less so than NaF. 4. Both NaF and MgSO4 alone have a stabilizing effect during solubilization. The greatest amounts of soluble activity were obtained with both agents present in the solubilization medium, there being a synergistic effect. PMID:568467

The p14 fusion-associated small transmembrane (FAST) protein effects membrane fusion from a subset of membrane microdomains.

PubMed

Corcoran, Jennifer A; Salsman, Jayme; de Antueno, Roberto; Touhami, Ahmed; Jericho, Manfred H; Clancy, Eileen K; Duncan, Roy

2006-10-20

The reovirus fusion-associated small transmembrane (FAST) proteins are a unique family of viral membrane fusion proteins. These nonstructural viral proteins induce efficient cell-cell rather than virus-cell membrane fusion. We analyzed the lipid environment in which the reptilian reovirus p14 FAST protein resides to determine the influence of the cell membrane on the fusion activity of the FAST proteins. Topographical mapping of the surface of fusogenic p14-containing liposomes by atomic force microscopy under aqueous conditions revealed that p14 resides almost exclusively in thickened membrane microdomains. In transfected cells, p14 was found in both Lubrol WX- and Triton X-100-resistant membrane complexes. Cholesterol depletion of donor cell membranes led to preferential disruption of p14 association with Lubrol WX (but not Triton X-100)-resistant membranes and decreased cell-cell fusion activity, both of which were reversed upon subsequent cholesterol repletion. Furthermore, co-patching analysis by fluorescence microscopy indicated that p14 did not co-localize with classical lipid-anchored raft markers. These data suggest that the p14 FAST protein associates with heterogeneous membrane microdomains, a distinct subset of which is defined by cholesterol-dependent Lubrol WX resistance and which may be more relevant to the membrane fusion process.

Differential detergent resistance of the apical and basolateral NPPases: relationship with polarized targeting.

PubMed

Delaunay, Jean-Louis; Breton, Michelyne; Goding, James W; Trugnan, Germain; Maurice, Michèle

2007-03-15

Targeting of glycosylphosphatidylinositol-anchored proteins to the apical surface of epithelial cells involves clustering in Triton X-100-resistant membrane microdomains or rafts. The role of these microdomains in sorting transmembrane proteins is more questionable because, unlike glycosylphosphatidylinositol-anchored proteins, apical transmembrane proteins are rather soluble in Triton X-100. They are, however, resistant to milder detergents such as Lubrol WX or Tween 20. It has been proposed that specific membrane microdomains, defined by resistance to these detergents, would carry transmembrane proteins to the apical surface. We have used MDCK cells stably transfected with the apical and basolateral pyrophosphatases/phosphodiesterases, NPP3 and NPP1, to examine the relationship between detergent resistance and apical targeting. The apically expressed wild-type NPP3 was insoluble in Lubrol WX whereas wild-type NPP1, which is expressed basolaterally, was essentially soluble. By using tail mutants and chimeric constructs that combine the cytoplasmic, transmembrane and extracellular domains of NPP1 and NPP3, we show that there is not a strict correlation between detergent resistance and apical targeting. Lubrol resistance is an intrinsic property of NPP3, which is acquired early during the biosynthetic process irrespective of its final destination, and depends on positively charged residues in its cytoplasmic tail.

Structure-activity relationships on the study of β-galactosidase folding/unfolding due to interactions with immobilization additives: Triton X-100 and ethanol.

PubMed

Soto, Dayana; Escobar, Sindy; Guzmán, Fanny; Cárdenas, Constanza; Bernal, Claudia; Mesa, Monica

2017-03-01

Improving the enzyme stability is a challenge for allowing their practical application. The surfactants are stabilizing agents, however, there are still questions about their influence on enzyme properties. The structure-activity/stability relationship for β-galactosidase from Bacillus circulans is studied here by Circular Dichroism and activity measurements, as a function of temperature and pH. The tendency of preserving the β-sheet and α-helix structures at temperatures below 65°C and different pH is the result of the balance between the large- and short-range effects, respecting to the active site. This information is fundamental for explaining the structural changes of this enzyme in the presence of Triton X-100 surfactant and ethanol. The enzyme thermal stabilization in the presence of this surfactant responds to the rearrangement of the secondary structure for having optimal activity/stability. The effect of ethanol is more related with changes in the dielectric properties of the aqueous solution than with protein structural transformations. These results contribute to understand the effects of surfactant-enzyme interactions on the enzyme behavior, from the structural point of view and to rationalize the surfactant-based stabilizing strategies for β-galactosidades. Copyright © 2016 Elsevier B.V. All rights reserved.

Improvement on D-xylose to Xylitol Biotransformation by Candida guilliermondii Using Cells Permeabilized with Triton X-100 and Selected Process Conditions.

PubMed

Cortez, Daniela Vieira; Mussatto, Solange I; Roberto, Inês Conceição

2016-11-01

Cells of Candida guilliermondii permeabilized with Triton X-100 were able to efficiently produce xylitol from a medium composed only by D-xylose and MgCl 2 ·6H 2 O in potassium phosphate buffer, at 35 °C and pH 6.5. Under these conditions, the results were similar to those obtained when cofactor and co-substrate or nutrients were added to the medium (about 95 % D-xylose was assimilated producing 42 g/L of xylitol, corresponding to 0.80 g/g yield and 2.65 g/L h volumetric productivity). Furthermore, the permeabilized cells kept the D-xylose assimilation in about 90 % and the xylitol production in approx. 40 g/L during three bioconversion cycles of 16 h each. These values are highly relevant when compared to others reported in the literature using enzyme technology and fermentative process, thereby demonstrating the effectiveness of the proposed method. The present study reveals that the use of permeabilized cells is an interesting alternative to obtain high xylitol productivity using low cost medium formulation. This approach may allow the future development of xylitol production from xylose present in lignocellulosic biomass, with additional potential for implementation in biorefinery strategies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rouyer-Fessard, P.; Garel, M.C.; Domenget, C.

The soluble pool of alpha hemoglobin chains present in blood or bone marrow cells was measured with a new affinity method using a specific probe, beta A hemoglobin chain labeled with ({sup 3}H)N-ethylmaleimide. This pool of soluble alpha chains was 0.067 {plus minus} 0.017% of hemoglobin in blood of normal adult, 0.11 {plus minus} 0.03% in heterozygous beta thalassemia and ranged from 0.26 to 1.30% in homozygous beta thalassemia intermedia. This elevated pool of soluble alpha chains observed in human beta thalassemia intermedia decreased 33-fold from a value of 10% of total hemoglobin in bone marrow cells to 0.3% inmore » the most dense red blood cells. The amount of insoluble alpha chains was measured by using the polyacrylamide gel electrophoresis in urea and Triton X-100. In beta thalassemia intermedia the amount of insoluble alpha chains was correlated with the decreased spectrin content of red cell membrane and was associated with a decrease in ankyrin and with other abnormalities of the electrophoretic pattern of membrane proteins. The loss and topology of the reactive thiol groups of membrane proteins was determined by using ({sup 3}H)N-ethylmaleimide added to membrane ghosts prior to urea and Triton X-100 electrophoresis. Spectrin and ankyrin were the major proteins with the most important decrease of thiol groups.« less

Degradation of alkylphenol ethoxylate surfactants in water with ultrasonic irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Destaillats, H.; Hung, H.M.; Hoffmann, M.R.

2000-01-15

During the last years, many efforts have been devoted to the elimination of alkylphenol ethoxylate surfactants from aqueous systems. In this paper, the sonochemical degradation of aqueous solutions of Triton X-100 was performed at an ultrasonic frequency of 358 kHz and an applied power of 50 W. Analysis of the reaction products by HPLC-ES-MS suggests that the hydrophobic alkyl chain is the preferential site for oxidation. Alkylphenol, or short-chain ethoxylated phenols, were not generated as byproducts. To verify this hypothesis, the sonochemical degradation of the corresponding alkylphenols (e.g., tertoctylphenol) was performed under the same conditions; in these cases, similar ratemore » constants and products were observed. These results differ from those reported for the biodegradation of alkylphenol ethoxylates. A substantial increase in the rate constant was observed for the degradation of Triton X-100 below its critical micelle concentration. This observation indicates that micelle formation serves to effectively isolate the free surfactant monomers from the water-air interface of the oscillating cavitation bubbles, thus decreasing the overall efficiency of the sonochemical process. The hydrophobic tail of the molecule is no longer exposed directly to the bubble hot spot when it is pointed into the core of the micelles.« less

Removal of copper powder from aqueous solution by cementation using an agitated vessel.

PubMed

Amin, N K; El-Ashtouky, E-S Z; Abdelwahab, O

2014-01-01

The present study is concerned with the removal of copper powder from aqueous solution by cementation on a stationary disc placed inside an agitated vessel. The influence of several parameters on the rate of cementation, such as initial copper sulphate concentration, impeller rotational speed, presence of surfactant (Triton X-100), distance between the disc and the impeller, type of blade turbine and presence of baffles, has been investigated. The rate of cementation was found to increase with increasing impeller rotational speed and initial copper sulphate concentration. On the other hand, the rate decreases with increasing distance between the disc and the impeller. The rate of cementation was inhibited in solutions containing Triton X-100. Performance of a four-blade 90 degree turbine with regard to the rate of copper cementation was superior to the performance of a four-blade 45 degree pitched turbine. The present data can be correlated in terms of mass transfer coefficient of cementation as Sh = 0.905 Sc0.33 Re0.89 (d/l)0.41 (four-blade 90 degree turbine); Sh = 0.815 Sc0.33Re0.79 (d/l)0.47 (four-blade 45 degree pitched turbine), for the conditions 2035 < Sc < 2810 and 35,000 < Re < 179,000.

The Relationship between Fenestrations, Sieve Plates and Rafts in Liver Sinusoidal Endothelial Cells

PubMed Central

McNerney, Gregory P.; Owen, Dylan M.; Zencak, Dusan; Zykova, Svetlana N.; Crane, Harry; Huser, Thomas; Quinn, Ronald J.; Smedsrød, Bård; Le Couteur, David G.; Cogger, Victoria C.

2012-01-01

Fenestrations are transcellular pores in endothelial cells that facilitate transfer of substrates between blood and the extravascular compartment. In order to understand the regulation and formation of fenestrations, the relationship between membrane rafts and fenestrations was investigated in liver sinusoidal endothelial cells where fenestrations are grouped into sieve plates. Three dimensional structured illumination microscopy, scanning electron microscopy, internal reflectance fluorescence microscopy and two-photon fluorescence microscopy were used to study liver sinusoidal endothelial cells isolated from mice. There was an inverse distribution between sieve plates and membrane rafts visualized by structured illumination microscopy and the fluorescent raft stain, Bodipy FL C5 ganglioside GM1. 7-ketocholesterol and/or cytochalasin D increased both fenestrations and lipid-disordered membrane, while Triton X-100 decreased both fenestrations and lipid-disordered membrane. The effects of cytochalasin D on fenestrations were abrogated by co-administration of Triton X-100, suggesting that actin disruption increases fenestrations by its effects on membrane rafts. Vascular endothelial growth factor (VEGF) depleted lipid-ordered membrane and increased fenestrations. The results are consistent with a sieve-raft interaction, where fenestrations form in non-raft lipid-disordered regions of endothelial cells once the membrane-stabilizing effects of actin cytoskeleton and membrane rafts are diminished. PMID:23029409

Enhanced preferential cytotoxicity through surface modification: synthesis, characterization and comparative in vitro evaluation of TritonX-100 modified and unmodified zinc oxide nanoparticles in human breast cancer cell (MDA-MB-231).

PubMed

Kc, Biplab; Paudel, Siddhi Nath; Rayamajhi, Sagar; Karna, Deepak; Adhikari, Sandeep; Shrestha, Bhupal G; Bisht, Gunjan

2016-01-01

Nanoparticles (NPs) are receiving increasing interest in biomedical research owing to their comparable size with biomolecules, novel properties and easy surface engineering for targeted therapy, drug delivery and selective treatment making them a better substituent against traditional therapeutic agents. ZnO NPs, despite other applications, also show selective anticancer property which makes it good option over other metal oxide NPs. ZnO NPs were synthesized by chemical precipitation technique, and then surface modified using Triton X-100. Comparative study of cytotoxicity of these modified and unmodified NPs on breast cancer cell line (MDA-MB-231) and normal cell line (NIH 3T3) were carried out. ZnO NPsof average size 18.67 ± 2.2 nm and Triton-X modified ZnO NPs of size 13.45 ± 1.42 nm were synthesized and successful characterization of synthesized NPs was done by Fourier transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD), transmission electron microscopy (TEM) analysis. Surface modification of NPs was proved by FT-IR analysis whereas structure and size by XRD analysis. Morphological analysis was done by TEM. Cell viability assay showed concentration dependent cytotoxicity of ZnO NPs in breast cancer cell line (MDA-MB-231) whereas no positive correlation was found between cytotoxicity and increasing concentration of stress in normal cell line (NIH 3T3) within given concentration range. Half maximum effective concentration (EC50) value for ZnO NPs was found to be 38.44 µg/ml and that of modified ZnO NPs to be 55.24 µg/ml for MDA-MB-231. Crystal violet (CV) staining image showed reduction in number of viable cells in NPs treated cell lines further supporting this result. DNA fragmentation assay showed fragmented bands indicating that the mechanism of cytotoxicity is through apoptosis. Although use of surfactant decreases particle size, toxicity of modified ZnO NPs were still less than unmodified NPs on MDA-MB-231 contributed by biocompatible surface coating. Both samples show significantly less toxicity towards NIH 3T3 in concentration independent manner. But use of Triton-X, a biocompatible polymer, enhances this preferentiality effect. Since therapeutic significance should be analyzed through its comparative effect on both normal and cancer cells, possible application of biocompatible polymer modified nanoparticles as therapeutic agent holds better promise.Graphical abstractSurface coating, characterization and comparative in vitro cytotoxicity study on MDA-MB 231 and NIH 3T3 of ZnO NPs showing enhanced preferentiality by biocompatible surface modification.

Function of the alpha 6 Integrins in Breast Carcinoma

DTIC Science & Technology

2001-10-01

motility on laminin-1. Time-lapse was resistant to solubilization with Triton X-100. Cy- videomicroscopy of clone A cells on laminin-1 revealed...represent SEM. The Integrin a6/34 Participates in the Dynamic Formation of Actin-based Motility Structures: Filopodia lapse videomicroscopy in serum-free...threefold greater time-lapse videomicroscopy to understand how the cu6P34 than on an equivalent concentration of collagen type I, integrin contributes to

Mechanisms of Chemoresistance in Breast Cancer Cells

DTIC Science & Technology

2008-02-01

which blocks ganglioside biosynthesis at the juncture of ceramide synthase, or Vibrio cholerae neuraminidase, which cleaves cell surface gangliosides...MCF-7-AdrR and MCF-7-AdrR/GCS antisense cells were rinsed, harvested in PBS, and lysed in a PBS buffer containing 10% glycerol, 1% Triton X-100, 1.0...analysis of gangliosides. Cells harvested in PBS were homogenized in 6 mL chloroform/methanol (1:1, v/v); the mixture remained overnight at room

Infrared spectroscopy of Triton and Pluto ice analogs: the case for saturated hydrocarbons.

PubMed

Bohn, R B; Sandford, S A; Allamandola, L J; Cruikshank, D P

1994-09-01

The infrared transmission spectra and photochemical behavior of various organic compounds isolated in solid N2 ices, appropriate for applications to Triton and Pluto, are presented. It is shown that excess absorption in the surface spectra of Triton and Pluto, i.e., absorption not explained by present models incorporating molecules already identified on these bodies (N2, CH4, CO, and CO2), that starts near 4450 cm-1 (2.25 micrometers) and extends to lower frequencies, may be due to alkanes (C(n)H2n+2) and related molecules frozen in the nitrogen. Branched and linear alkanes may be responsible. Experiments in which the photochemistry of N2:CH4 and N(2):CH4:CO ices was explored demonstrate that the surface ices of Triton and Pluto may contain a wide variety of additional species containing H, C, O, and N. Of these, the reactive molecule diazomethane, CH2N2, is particularly important since it may be largely responsible for the synthesis of larger alkanes from CH4 and other small alkanes. Diazomethane would also be expected to drive chemical reactions involving organics in the surface ices of Triton and Pluto toward saturation, i.e., to reduce multiple CC bonds. The positions and intrinsic strengths (A values) of many of the infrared absorption bands of N2 matrix-isolated molecules of relevance to Triton and Pluto have also been determined. These can be used to aid in their search and to place constraints on their abundances. For example, using these A values the abundance ratios CH4/N2 approximately 1.3 x 10(-3), C2H4/N2 < or = 9.5 x 10(-7) and H2CO/N2 < or = 7.8 x 10(-7) are deduced for Triton and CH4/N2 approximately 3.1 x 10(-3), C2H4/N2 < or = 4.1 x 10(-6), and H2CO/N2 < or = 5.2 x 10(-6) deduced for Pluto. The small amounts of C2H4 and H2CO in the surface ices of these bodies are in disagreement with the large abundances expected from many theoretical models.

Non-chromatographic speciation of chromium at sub-ppb levels using cloud point extraction in the presence of unmodified silver nanoparticles.

PubMed

López-García, Ignacio; Vicente-Martínez, Yesica; Hernández-Córdoba, Manuel

2015-01-01

The cloud point extraction (CPE) of silver nanoparticles (AgNPs) by Triton X-114 allows chromium (III) ions to be transferred to the surfactant-rich phase, where they can be measured by electrothermal atomic absorption spectrometry. Using 20 mL sample and 50 μL Triton X-114 (30% w/v), the enrichment factor was 1150, and calibration graphs were obtained in the 5-100 ng L(-1) chromium range in the presence of 5 µg L(-1) AgNPs. Speciation of trivalent and hexavalent chromium was achieved by carrying out two CPE experiments, one of them in the presence of ethylenediaminetetraacetate. While in the first experiment, in absence of the complexing agent, the concentration of total chromium was obtained, the analytical signal measured in the presence of this chemical allowed the chromium (VI) concentration to be measured, being that of chromium (III) calculated by difference. The reliability of the procedure was verified by using three standard reference materials before applying to water, beer and wine samples. Copyright © 2014 Elsevier B.V. All rights reserved.

A Rapid and Inexpensive PCR-Based STR Genotyping Method for Identifying Forensic Specimens

DTIC Science & Technology

2006-06-01

this report) 20. Security Classif. (of this page) 21 . No. of Pages 22. Price Unclassified Unclassified 18 Form DOT F 1700.7 (8-72) Reproduction of...Promega PowerPlex 2.1 system (7) except that the buffer was 1x Amplitaq gold reaction buffer, 0.1% TritonX-100, and 0.2mM each dNTP in a 25µl final...electrophoresis were done using the PowerPlex 16 System (Promega Corp.; Madison, WI). rEsulTs ANd dIsCussION The goal of this study was to develop a simple DNA

Use of Monoclonal Antibodies to Study the Structural Basis of the Function of Nicotinic Acetylcholine Receptors on Electric Organ and Muscle and to Determine the Structure of Nicotinic Acetylcholine Receptors on Neurons

DTIC Science & Technology

1989-09-30

polyethylenimine . The filters were washed with 3x4 ml of the same buffer and bound radioactivity was determined by scintillation counting. Nonspecific binding was...then autoradiographed for 6 hours on preflashed8 Kodak XAR film . Samples in 5..pl aliquots were applied to freshly glow- discharged carbon support...quench buffer containing 0.5% Triton X-100. The membrane was washed with buffer and autoradiographed orn preflashed Kodak XAR5 film . Geysen Epitope

Behavior of yeast cells in aqueous suspension affected by pulsed electric field.

PubMed

El Zakhem, H; Lanoisellé, J-L; Lebovka, N I; Nonus, M; Vorobiev, E

2006-08-15

This work discusses pulsed electric fields (PEF) induced effects in treatment of aqueous suspensions of concentrated yeast cells (S. cerevisiae). The PEF treatment was done using pulses of near-rectangular shape, electric field strength was within E=2-5 kV/cm and the total time of treatment was t(PEF)=10(-4)-0.1 s. The concentration of aqueous yeast suspensions was in the interval of C(Y)=0-22 (wt%), where 1% concentration corresponds to the cellular density of 2x10(8) cells/mL. Triton X-100 was used for studying non-ionic surfactant additive effects. The electric current peak value I was measured during each pulse application, and from these data the electrical conductivity sigma was estimated. The PEF-induced damage results in increase of sigma with t(PEF) increasing and attains its saturation level sigma approximately sigma(max) at long time of PEF treatment. The value of sigma(max) reflects the efficiency of damage. The reduced efficiency of damage at suspension volume concentration higher than phi(Y) approximately 32 vol% is explained by the percolation phenomenon in the randomly packed suspension of near-spherical cells. The higher cytoplasmic ions leakage was observed in presence of surfactant. Experiments were carried out in the static and continuous flow treatment chambers in order to reveal the effects of mixing in PEF-treatment efficiency. A noticeable aggregation of the yeast cells was observed in the static flow chamber during the PEF treatment, while aggregation was not so pronounced in the continuous flow chamber. The nature of the enhanced aggregation under the PEF treatment was revealed by the zeta-potential measurements: these data demonstrate different zeta-potential signs for alive and dead cells. The effect of the electric field strength on the PEF-induced extraction of the intracellular components of S. cerevisiae is discussed.

Proteomic analysis of amphiphilic proteins of hexaploid wheat kernels.

PubMed

Amiour, Nardjis; Merlino, Marielle; Leroy, Philippe; Branlard, Gérard

2002-06-01

Wheat proteins and specially gluten proteins have been well studied and are closely associated with baking products. Amphiphilic proteins (proteins that are soluble using nonionic detergent Triton X-114 ) also play an important role in wheat quality. Some of them, like puroindolines, are lipid binding proteins, and are strongly linked to dough foaming properties and to fine crumb texture. However many amphiphilic proteins are still unknown and both their physiological and technological functions remain to be analysed. In order to explore these proteins, proteomic analysis was carried out using 81 F9 lines, progeny obtained from an interspecific cross "W7984"x"Opata", and already used to built a map of more than 2000 molecular markers (International Triticeae Mapping Initiative, ITMImap). Two-dimensional electrophoresis (immobilized pH gradient (pH 6-11)x sodium dodecyl sulfate-polyacrylamide gel electrophoresis) was performed on amphiphilic proteins with three to five replicates for each line. Silver stained gels were analysed using Melanie 3 software. Genetic determinism was carried out on 170 spots segregating between the two parental hexaploïd wheats. Many of these spots were mapped on different chromosomes of the ITMImap. Spots of interest were identified using matrix-assisted laser desorption/ionization-time of flight and some of them were partly sequenced using electrospray ionization-tandem mass spectrometry. This proteomic approach provided some very useful information about some proteic components linked to bread wheat quality and particularly to kernel hardness.

The monocarboxylate carrier from rat liver mitochondria. Purification and kinetic characterization in a reconstituted system.

PubMed

Capuano, F; Di Paola, M; Azzi, A; Papa, S

1990-02-12

The monocarboxylate (pyruvate) carrier was extracted from rat liver mitochondria with Triton X-100 in the presence of asolectin and partially purified by chromatography on HTP. The HTP eluate reconstituted in liposomes was shown to catalyze active pyruvatein/acetoacetateout and acetoacetatein/pyruvateout counter-exchange. Kinetic characterization of the reconstituted pyruvate carrier was achieved by an original spectrophotometric method consisting of determination of substrate release from proteoliposomes with a coupled enzymatic assay.

Cell Activation Mediated by Glycosylphosphatidylinositol-Anchored or Transmembrane Forms of CD14†

PubMed Central

Pugin, J.; Kravchenko, V. V.; Lee, J.-D.; Kline, L.; Ulevitch, R. J.; Tobias, P. S.

1998-01-01

CD14 is a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein which functions as a receptor on myeloid cells for ligands derived from microbial pathogens such as lipopolysaccharide (LPS). We have studied the importance of the GPI tail of CD14 in signalling with the promonocytic cell line THP-1 expressing recombinant CD14 in a GPI-anchored form (THP1-wtCD14 cells) or in a transmembrane form (THP1-tmCD14). We found that, like other GPI-anchored molecules, GPI-anchored CD14 was recovered mainly from a Triton X-100-insoluble fraction, whereas transmembrane CD14 was fully soluble in Triton X-100. LPS induced cell activation of THP1-wtCD14 and of THP1-tmCD14 (protein tyrosine kinase phosphorylation, NF-κB activation, and cytokine production) in a very similar manner. However, anti-CD14 antibody-induced cross-linking caused a rapid calcium mobilization signal only in GPI-anchored CD14 cells. Studies with pharmacologic inhibitors of intracellular signalling events implicate phospholipase C and protein tyrosine kinases in the genesis of this antibody-induced calcium signal. Our results suggest that GPI anchoring and CD14 targeting to glycolipid-rich membrane microdomains are not required for LPS-mediated myeloid cell activation. GPI anchoring may however be important for other signalling functions, such as those events reflected by antibody cross-linking. PMID:9488411

Hydrodynamic properties of porcine bestrophin-1 in Triton X-100.

PubMed

Stanton, J Brett; Goldberg, Andrew F X; Hoppe, George; Marmorstein, Lihua Y; Marmorstein, Alan D

2006-02-01

Bestrophin-1 (Best-1) is an integral membrane protein, defects in which cause Best vitelliform macular dystrophy. Best-1 is proposed to function as a Cl- channel and/or a regulator of Ca++ channels. A tetrameric (or pentameric) stoichiometry has been reported for recombinant best-1. Using a combination of gel exclusion chromatography and velocity sedimentation we examined the quaternary structure of native best-1 and found that it migrates as a single species with a Stokes radius of 7.3 nm, sedimentation coefficient (S20,w) of 4.9, and partial specific volume (nu) of 0.80 ml/g. The mass of the protein-detergent complex is calculated to be 206 kDa, with the protein component estimated to be approximately 138 kDa. Given a monomeric mass of 68 kDa, we conclude that native best-1 solubilized with Triton X-100 is a homodimer. The differences between this observation and a prior report were examined by comparing recombinant best-1 with tissue derived best-1 using gel exclusion chromatography. Much of the recombinant best-1 eluted in the column void (Vo) fraction, unlike that extracted from RPE cells. We conclude that the minimal functional unit of best-1 is dimeric. This stoichiometry differs from that previously measured for recombinant best-1, suggesting that further studies are necessary to determine the stoichiometry of functional best-1 in RPE membranes.

Impact of Detergents on Membrane Protein Complex Isolation.

PubMed

Lee, Yu-Chen; Bååth, Jenny Arnling; Bastle, Ryan M; Bhattacharjee, Sonali; Cantoria, Mary Jo; Dornan, Mark; Gamero-Estevez, Enrique; Ford, Lenzie; Halova, Lenka; Kernan, Jennifer; Kürten, Charlotte; Li, Siran; Martinez, Jerahme; Sachan, Nalani; Sarr, Medoune; Shan, Xiwei; Subramanian, Nandhitha; Rivera, Keith; Pappin, Darryl; Lin, Sue-Hwa

2018-01-05

Detergents play an essential role during the isolation of membrane protein complexes. Inappropriate use of detergents may affect the native fold of the membrane proteins, their binding to antibodies, or their interaction with partner proteins. Here we used cadherin-11 (Cad11) as an example to examine the impact of detergents on membrane protein complex isolation. We found that mAb 1A5 could immunoprecipitate Cad11 when membranes were solubilized by dodecyl maltoside (DDM) but not by octylglucoside, suggesting that octylglucoside interferes with Cad11-mAb 1A5 interaction. Furthermore, we compared the effects of Brij-35, Triton X-100, cholate, CHAPSO, Zwittergent 3-12, Deoxy BIG CHAP, and digitonin on Cad11 solubilization and immunoprecipitation. We found that all detergents except Brij-35 could solubilize Cad11 from the membrane. Upon immunoprecipitation, we found that β-catenin, a known cadherin-interacting protein, was present in Cad11 immune complex among the detergents tested except Brij-35. However, the association of p120 catenin with Cad11 varied depending on the detergents used. Using isobaric tag for relative and absolute quantitation (iTRAQ) to determine the relative levels of proteins in Cad11 immune complexes, we found that DDM and Triton X-100 were more efficient than cholate in solubilization and immunoprecipitation of Cad11 and resulted in the identification of both canonical and new candidate Cad11-interacting proteins.

Microemulsion-enhanced remediation of soils contaminated with organochlorine pesticides.

PubMed

Zhang, Yanlin; Wong, Jonathan W C; Zhao, Zhenyong; Selvam, Ammaiyappan

2011-12-01

Soil contaminated by organic pollutants, especially chlorinated aromatic compounds such as DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), is an environmental concern because of the strong sorption of organochlorine pesticide onto the soil matrix and persistence in the environment. The remediation of organochlorine pesticide contaminated soils through microemulsion is an innovative technology to expedite this process. The remediation efficiency was evaluated by batch experiments through studying the desorption of DDT and hexachlorocyclohexane (y-HCH) and sorption of microemulsion composed of Triton X-100, 1-pentanol and linseed oil in the soil-surfactant-water suspension system. The reduction of desorption efficiency caused by the sorption loss of microemulsion components onto the soil could be corrected by the appropriate adjustment of C/S (Cosurfactant/Surfactant) and O/S (Oil/Surfactant) ratio. The C/S and O/S ratios of 1:2 and 3:20 were suitable to desorb DDT and gamma-HCH from the studied soils because of the lower sorption of Triton X-100 onto the soil. Inorganic salts added in microemulsion increased the pesticides desorption efficiency of pesticides and calcium chloride has a stronger ability to enhance the desorption of DDT than sodium chloride. From the remediation perspective, the balance of surfactant or cosurfactant sorbed to soil and desorption efficiency should be taken into consideration to enhance the remediation of soils contaminated by organochlorine pesticides.

Effect of C/N Ratio and Media Optimization through Response Surface Methodology on Simultaneous Productions of Intra- and Extracellular Inulinase and Invertase from Aspergillus niger ATCC 20611

PubMed Central

Dinarvand, Mojdeh; Rezaee, Malahat; Masomian, Malihe; Jazayeri, Seyed Davoud; Zareian, Mohsen; Abbasi, Sahar; Ariff, Arbakariya B.

2013-01-01

The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes from Aspergillus niger ATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO3, Zn+2, and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R 2) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO3, 1.5 mM (v/v) Zn+2, and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry. PMID:24151605

Lipid raft integrity affects GABAA receptor, but not NMDA receptor modulation by psychopharmacological compounds.

PubMed

Nothdurfter, Caroline; Tanasic, Sascha; Di Benedetto, Barbara; Uhr, Manfred; Wagner, Eva-Maria; Gilling, Kate E; Parsons, Chris G; Rein, Theo; Holsboer, Florian; Rupprecht, Rainer; Rammes, Gerhard

2013-07-01

Lipid rafts have been shown to play an important role for G-protein mediated signal transduction and the function of ligand-gated ion channels including their modulation by psychopharmacological compounds. In this study, we investigated the functional significance of the membrane distribution of NMDA and GABAA receptor subunits in relation to the accumulation of the tricyclic antidepressant desipramine (DMI) and the benzodiazepine diazepam (Diaz). In the presence of Triton X-100, which allowed proper separation of the lipid raft marker proteins caveolin-1 and flotillin-1 from the transferrin receptor, all receptor subunits were shifted to the non-raft fractions. In contrast, under detergent-free conditions, NMDA and GABAA receptor subunits were detected both in raft and non-raft fractions. Diaz was enriched in non-raft fractions without Triton X-100 in contrast to DMI, which preferentially accumulated in lipid rafts. Impairment of lipid raft integrity by methyl-β-cyclodextrine (MβCD)-induced cholesterol depletion did not change the inhibitory effect of DMI at the NMDA receptor, whereas it enhanced the potentiating effect of Diaz at the GABAA receptor at non-saturating concentrations of GABA. These results support the hypothesis that the interaction of benzodiazepines with the GABAA receptor likely occurs outside of lipid rafts while the antidepressant DMI acts on ionotropic receptors both within and outside these membrane microdomains.

Voyager radio science observations of neptune and triton.

PubMed

Tyler, G L; Sweetnam, D N; Anderson, J D; Borutzki, S E; Campbell, J K; Eshleman, V R; Gresh, D L; Gurrola, E M; Hinson, D P; Kawashima, N; Kursinski, E R; Levy, G S; Lindal, G F; Lyons, J R; Marouf, E A; Rosen, P A; Simpson, R A; Wood, G E

1989-12-15

The Voyager 2 encounter with the Neptune system included radio science investigations of the masses and densities of Neptune and Triton, the low-order gravitational harmonics of Neptune, the vertical structures of the atmospheres and ionospheres of Neptune and Triton, the composition of the atmosphere of Neptune, and characteristics of ring material. Demanding experimental requirements were met successfully, and study of the large store of collected data has begun. The initial search of the data revealed no detectable effects of ring material with optical depth tau [unknown] 0.01. Preliminary representative results include the following: 1.0243 x 10(26) and 2.141 x 10(22) kilograms for the masses of Neptune and Triton; 1640 and 2054 kilograms per cubic meter for their respective densities; 1355 +/- 7 kilometers, provisionally, for the radius of Triton; and J(2) = 3411 +/- 10(x 10(-6)) and J(4) = -26(+12)(-20)(x10(-6)) for Neptune's gravity field (J>(2) and J(4) are harmonic coefficients of the gravity field). The equatorial and polar radii of Neptune are 24,764 +/- 20 and 24,340 +/- 30 kllometers, respectively, at the 10(5)-pascal (1 bar) pressure level. Neptune's atmosphere was probed to a pressure level of about 5 x 10(5) pascals, and effects of a methane cloud region and probable ammonia absorption below the cloud are evident in the data. Results for the mixing ratios of helium and ammonia are still being investigated; the methane abundance below the clouds is at least 1 percent by volume. Derived temperature-pressure profiles to 1.2 x 10(5) pascals and 78 kelvins (K) show a lapse rate corresponding to "frozen" equilibrium of the para- and ortho-hydrogen states. Neptune's ionosphere exhibits an extended topside at a temperature of 950 +/- 160 K if H(+) is the dominant ion, and narrow ionization layers of the type previously seen at the other three giant planets. Triton has a dense ionosphere with a peak electron concentration of 46 x 10(9) per cubic meter at an altitude of 340 kilometers measured during occultation egress. Its topside plasma temperature is about 80 +/- 16 K if N(2)(+) is the principal ion. The tenuous neutral atmosphere of Triton produced distinct signatures in the occultation data; however, the accuracy of the measurements is limited by uncertainties in the frequency of the spacecraft reference oscillator. Preliminary values for the surface pressure of 1.6 +/- 0.3 pascals and an equivalent isothermal temperature of 48 +/- 5 K are suggested, on the assumption that molecular nitrogen dominates the atmosphere. The radio data may be showing the effects of a thermal inversion near the surface; this and other evidence imply that the Triton atmosphere is controlled by vapor-pressure equilibrium with surface ices, at a temperature of 38 K and a methane mixing ratio of about 10(-4).

Activation status-coupled transient S acylation determines membrane partitioning of a plant Rho-related GTPase.

PubMed

Sorek, Nadav; Poraty, Limor; Sternberg, Hasana; Bar, Enat; Lewinsohn, Efraim; Yalovsky, Shaul

2007-03-01

ROPs or RACs are plant Rho-related GTPases implicated in the regulation of a multitude of signaling pathways that function at the plasma membrane by virtue of posttranslational lipid modifications. The relationship between ROP activation status and membrane localization has not been established. Here we demonstrate that endogenous ROPs, as well as a transgenic His(6)-green fluorescent protein (GFP)-AtROP6 fusion protein, were partitioned between Triton X-100-soluble and -insoluble membranes. In contrast, an activated His(6)-GFP-Atrop6(CA) mutant protein accumulated exclusively in detergent-resistant membranes. GDP induced accumulation of ROPs in Triton-soluble membranes, whereas GTPgammaS induced accumulation of ROPs in detergent-resistant membranes. Recombinant wild-type and constitutively active AtROP6 isoforms were purified from Arabidopsis plants, and their lipids were cleaved and analyzed by gas chromatography-coupled mass spectrometry. In Triton-soluble membranes, wild-type AtROP6 was only prenylated, primarily by geranylgeranyl. The activated AtROP6 that accumulated in detergent-resistant membranes was modified by prenyl and acyl lipids. The acyl lipids were identified as palmitic and stearic acids. In agreement, activated His(6)-GFP-Atrop6(CA)mS(156) in which cysteine(156) was mutated into serine accumulated in Triton-soluble membranes. These findings show that upon GTP binding and activation, AtROP6 and possibly other ROPs are transiently S acylated, which induces their partitioning into detergent-resistant membranes.

Corrected and Republished from: Activation Status-Coupled Transient S-Acylation Determines Membrane Partitioning of a Plant Rho-Related GTPase.

PubMed

Sorek, Nadav; Poraty, Limor; Sternberg, Hasana; Buriakovsky, Ella; Bar, Einat; Lewinsohn, Efraim; Yalovsky, Shaul

2017-12-01

ROPs or RACs are plant Rho-related GTPases implicated in the regulation of a multitude of signaling pathways that function at the plasma membrane via posttranslational lipid modifications. The relationships between ROP activation status and membrane localization has not been established. Here, we show that endogenous ROPs, as well as a transgenic His 6 -green fluorescent protein (GFP)- Arabidopsis thaliana ROP6 (AtROP6) fusion protein, were partitioned between Triton X-100-soluble and -insoluble membranes. In contrast, the His 6 -GFP-Atrop6 CA activated mutant accumulated exclusively in detergent-resistant membranes. GDP induced accumulation of ROPs in Triton-soluble membranes, whereas GTPγS induced accumulation of ROPs in detergent-resistant membranes. Recombinant wild-type and constitutively active AtROP6 proteins were purified from Arabidopsis plants, and in turn, their lipids were cleaved and analyzed by gas chromatography-coupled mass spectrometry. In Triton-soluble membranes, the wild-type AtROP6 was only prenylated, primarily by geranylgeranyl. The activated AtROP6 that accumulated in detergent-resistant membranes was modified by prenyl and acyl lipids, identified as palmitic and stearic acids. Consistently, activated His 6 -GFP-Atrop6 CA mS 156 , in which C156 was mutated into serine, accumulated in Triton-soluble membranes. These findings show that upon GTP binding and activation, AtROP6, and possibly other ROPs, are transiently S-acylated, inducing their partitioning into detergent-resistant membranes. Copyright © 2017 American Society for Microbiology.

Corrected and Republished from: Activation Status-Coupled Transient S-Acylation Determines Membrane Partitioning of a Plant Rho-Related GTPase

PubMed Central

Sorek, Nadav; Poraty, Limor; Sternberg, Hasana; Buriakovsky, Ella; Bar, Einat; Lewinsohn, Efraim

2017-01-01

ABSTRACT ROPs or RACs are plant Rho-related GTPases implicated in the regulation of a multitude of signaling pathways that function at the plasma membrane via posttranslational lipid modifications. The relationships between ROP activation status and membrane localization has not been established. Here, we show that endogenous ROPs, as well as a transgenic His6-green fluorescent protein (GFP)-Arabidopsis thaliana ROP6 (AtROP6) fusion protein, were partitioned between Triton X-100-soluble and -insoluble membranes. In contrast, the His6-GFP-Atrop6CA activated mutant accumulated exclusively in detergent-resistant membranes. GDP induced accumulation of ROPs in Triton-soluble membranes, whereas GTPγS induced accumulation of ROPs in detergent-resistant membranes. Recombinant wild-type and constitutively active AtROP6 proteins were purified from Arabidopsis plants, and in turn, their lipids were cleaved and analyzed by gas chromatography-coupled mass spectrometry. In Triton-soluble membranes, the wild-type AtROP6 was only prenylated, primarily by geranylgeranyl. The activated AtROP6 that accumulated in detergent-resistant membranes was modified by prenyl and acyl lipids, identified as palmitic and stearic acids. Consistently, activated His6-GFP-Atrop6CAmS156, in which C156 was mutated into serine, accumulated in Triton-soluble membranes. These findings show that upon GTP binding and activation, AtROP6, and possibly other ROPs, are transiently S-acylated, inducing their partitioning into detergent-resistant membranes. PMID:28894027

Temperature and thermal emissivity of the surface of Neptune's satellite Triton

NASA Technical Reports Server (NTRS)

Nelson, Robert M.; Smythe, William D.; Wallis, Brad D.; Horn, Linda J.; Lane, Arthur L.; Mayo, Marvin J.

1990-01-01

Analysis of the preliminary results from the Voyager mission to the Neptune system has provided the scientific community with several methods by which the temperature of Neptune's satellite Triton may be determined. If the 37.5 K surface temperature reported by several Voyager investigations is correct, then the photometry reported by the imaging experiment on Voyager requires that Triton's surface have a remarkably low emissivity. Such a low emissivity is not required in order to explain the photometry from the photopolarimeter experiment on Voyager. A low emissivity would be inconsistent with Triton having a rough surface at the about 100-micron scale as might be expected given the active renewal processes which appear to dominate Triton's surface.

Purification of CD47-streptavidin fusion protein from bacterial lysate using biotin-agarose affinity chromatography.

PubMed

Salehi, Nasrin; Peng, Ching-An

2016-07-08

CD47 is a widely expressed transmembrane glycoprotein that modulates the activity of a plethora of immune cells via its extracellular domain. Therefore, CD47 plays important roles in the regulation of immune responses and may serve as targets for the development of immunotherapeutic agents. To make sure CD47 functionality is intact under the process of protein conjugation, CD47-streptavidin fusion protein was expressed and purified because it can easily bind to biotin-tagged materials via the unique biotin-streptavidin affinity. In this study, gene sequences of CD47 extracellular domain (CD47ECD) and core streptavidin (coreSA) with a total 834 bp were inserted into pET20b plasmid to construct recombinant plasmid encoding CD47-SA fusion gene. After bacteria transformation, the CD47-SA fusion protein was expressed by isopropyl-β-d-thiogalactopyranoside (IPTG) induction. The collected bacteria lysate was loaded on biotinylated agarose to proceed the purification of CD47-SA fusion protein. Due to the unexpected high affinity between biotin and coreSA, standard washing and elution approaches (e.g., varying pH, using biotin, and applying guanidine hydrochloride) reported for biotin-streptavidin affinity chromatography were not able to separate the target fusion protein. Instead, using low concentration of the non-ionic detergent Triton X-100 followed with alkaline buffer could efficiently weaken the binding between biotin and coreSA, thereby eluting out CD47-SA fusion protein from the biotin agarose column. The purified CD47-SA fusion protein was further characterized by molecular biology methods and its antiphagocytic functionality was confirmed by the phagocytosis assay. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:949-958, 2016. © 2016 American Institute of Chemical Engineers.

Glycolipid-anchored proteins in neuroblastoma cells form detergent- resistant complexes without caveolin

PubMed Central

1995-01-01

It has been known for a number of years that glycosyl- phosphatidylinositol (GPI)-anchored proteins, in contrast to many transmembrane proteins, are insoluble at 4 degrees C in nonionic detergents such as Triton X-100. Recently, it has been proposed that this behavior reflects the incorporation of GPI-linked proteins into large aggregates that are rich in sphingolipids and cholesterol, as well as in cytoplasmic signaling molecules such as heterotrimeric G proteins and src-family tyrosine kinases. It has been suggested that these lipid-protein complexes are derived from caveolae, non-clathrin- coated invaginations of the plasmalemma that are abundant in endothelial cells, smooth muscle, and lung. Caveolin, a proposed coat protein of caveolae, has been hypothesized to be essential for formation of the complexes. To further investigate the relationship between the detergent-resistant complexes and caveolae, we have characterized the behavior of GPI-anchored proteins in lysates of N2a neuroblastoma cells, which lack morphologically identifiable caveolae, and which do not express caveolin (Shyng, S.-L., J. E. Heuser, and D. A. Harris. 1994. J. Cell Biol. 125:1239-1250). We report here that the complexes prepared from N2a cells display the large size and low buoyant density characteristic of complexes isolated from sources that are rich in caveolae, and contain the same major constituents, including multiple GPI-anchored proteins, alpha and beta subunits of heterotrimeric G proteins, and the tyrosine kinases fyn and yes. Our results argue strongly that detergent-resistant complexes are not equivalent to caveolae in all cell types, and that in neuronal cells caveolin is not essential for the integrity of these complexes. PMID:7537273

Effect of the Presence of Surfactants and Immobilization Conditions on Catalysts' Properties of Rhizomucor miehei Lipase onto Chitosan.

PubMed

de Oliveira, Ulisses M F; Lima de Matos, Leonardo J B; de Souza, Maria Cristiane M; Pinheiro, Bruna B; Dos Santos, José C S; Gonçalves, Luciana R B

2018-04-01

Lipase from Rhizomucor miehei (RML) was immobilized onto chitosan support in the presence of some surfactants added at low levels using two different strategies. In the first approach, the enzyme was immobilized in the presence of surfactants on chitosan supports previously functionalized with glutaraldehyde. In the second one, after prior enzyme adsorption on chitosan beads in the presence of surfactants, the complex chitosan beads-enzyme was then cross-linked with glutaraldehyde. The effects of surfactant concentrations on the activities of free and immobilized RML were evaluated. Hexadecyltrimethylammonium bromide (CTAB) promoted an inhibition of enzyme activity while the nonionic surfactant Triton X-100 caused a slight increase in the catalytic activity of the free enzyme and the derivatives produced in both methods of immobilization. The best derivatives were achieved when the lipase was firstly adsorbed on chitosan beads at 4 °C for 1 h, 220 rpm followed by cross-link the complex chitosan beads-enzyme with glutaraldehyde 0.6% v.v -1 at pH 7. The derivatives obtained under these conditions showed high catalytic activity and excellent thermal stability at 60° and 37 °C. The best derivative was also evaluated in the synthesis of two flavor esters namely methyl and ethyl butyrate. At non-optimized conditions, the maximum conversion yield for methyl butyrate was 89%, and for ethyl butyrate, the esterification yield was 92%. The results for both esterifications were similar to those obtained when the commercial enzyme Lipozyme® and free enzyme were used in the same reaction conditions and higher than the one achieved in the absence of the selected surfactant.

Determination of Ultra-trace Rhodium in Water Samples by Graphite Furnace Atomic Absorption Spectrometry after Cloud Point Extraction Using 2-(5-Iodo-2-Pyridylazo)-5-Dimethylaminoaniline as a Chelating Agent.

PubMed

Han, Quan; Huo, Yanyan; Wu, Jiangyan; He, Yaping; Yang, Xiaohui; Yang, Longhu

2017-03-24

A highly sensitive method based on cloud point extraction (CPE) separation/preconcentration and graphite furnace atomic absorption spectrometry (GFAAS) detection has been developed for the determination of ultra-trace amounts of rhodium in water samples. A new reagent, 2-(5-iodo-2-pyridylazo)-5-dimethylaminoaniline (5-I-PADMA), was used as the chelating agent and the nonionic surfactant TritonX-114 was chosen as extractant. In a HAc-NaAc buffer solution at pH 5.5, Rh(III) reacts with 5-I-PADMA to form a stable chelate by heating in a boiling water bath for 10 min. Subsequently, the chelate is extracted into the surfactant phase and separated from bulk water. The factors affecting CPE were investigated. Under the optimized conditions, the calibration graph was linear in the range of 0.1-6.0 ng/mL, the detection limit was 0.023 ng/mL for rhodium and relative standard deviation was 3.67% ( c = 1.0 ng/mL, n = 11)．The method has been applied to the determination of trace rhodium in water samples with satisfactory results.

Optimization of cloud point extraction and solid phase extraction methods for speciation of arsenic in natural water using multivariate technique.

PubMed

Baig, Jameel A; Kazi, Tasneem G; Shah, Abdul Q; Arain, Mohammad B; Afridi, Hassan I; Kandhro, Ghulam A; Khan, Sumaira

2009-09-28

The simple and rapid pre-concentration techniques viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As(3+) and total inorganic arsenic (iAs) in surface and ground water samples. The As(3+) was formed complex with ammonium pyrrolidinedithiocarbamate (APDC) and extracted by surfactant-rich phases in the non-ionic surfactant Triton X-114, after centrifugation the surfactant-rich phase was diluted with 0.1 mol L(-1) HNO(3) in methanol. While total iAs in water samples was adsorbed on titanium dioxide (TiO(2)); after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The multivariate strategy was applied to estimate the optimum values of experimental factors for the recovery of As(3+) and total iAs by CPE and SPE. The standard addition method was used to validate the optimized methods. The obtained result showed sufficient recoveries for As(3+) and iAs (>98.0%). The concentration factor in both cases was found to be 40.

Effect of Nanotube Film Thickness on the Performance of Nanotube-Silicon Hybrid Solar Cells

PubMed Central

Tune, Daniel D.; Shapter, Joseph G.

2013-01-01

The results of measurements on solar cells made from randomly aligned thin films of single walled carbon nanotubes (SWCNTs) on n-type monocrystalline silicon are presented. The films are made by vacuum filtration from aqueous TritonX-100 suspensions of large diameter arc-discharge SWCNTs. The dependence of the solar cell performance on the thickness of the SWCNT film is shown in detail, as is the variation in performance due to doping of the SWCNT film with SOCl2. PMID:28348358

United States Air Force Research Initiation Program for 1988. Volume 4

DTIC Science & Technology

1990-04-01

Wisconsin- Madison , Univ. of - 1 Trinity University - 1 Wright State University - 5 Total 153 vi PARTICIPANTS LABORATORY ASSIGNMENT vii PARTICIPANT...25 M sucrose by resuspension and recent- rifugation. Microsomes are suspended in 84 mL 5 uW Triton X-100(TRI), 50 WM K phosphate, pH 7.4, 5 mM...the litters. Rats in Groups B-i and B-2 were exposed to 300 ug/kg of beryllium sulfate (supplied by Aldridge Chemical Co., Madison , Wisconsin

A Receptor-Coupled Evanescent Biosensor

DTIC Science & Technology

1990-05-01

fibers ....................................... 18 6. The effects of various concentrations of d-TC (0), carbamyl- choline (&), and a𔃾GT (0) on binding of...affinity gel washed with the homogenization buffer containing 0.1% Triton X-100. The affinity gel was then mixed with 50 mL of 1 M carbamy- choline for 4 h...at 23*C, then filtered, and the filtrate, containing carbamyl- choline and the nAChR protein, was dialyzed against 5 mM Tris pH 7.2 to remove the drug

ELISA (Enzyme-linked Immunosorbent Assay) to Detect Humoral Antibodies Specific for Clostridium botulinum Type A Neurotoxin

DTIC Science & Technology

1985-11-19

10.6). Unbound toxoid was removed by washing three times with phosphate-buffered saline (pH 7.4) containing 0.05% Triton X-100 (Eastman Organic...MD) in phosphate-buffered saline was added. After a 90 min incubation period at 37*C, the excess conjugate was removed by washing each well three times...3. Cardella, M. A. 1964. Botulinum toxoids, p. 113-129. In K . H. Lewis and K . Cassel, Jr., (ed.), Botulism. U. S. Department of Health, Education

Epithelial structure revealed by chemical dissection and unembedded electron microscopy.

PubMed

Fey, E G; Capco, D G; Krochmalnic, G; Penman, S

1984-07-01

Cytoskeletal structures obtained after extraction of Madin-Darby canine kidney epithelial cell monolayers with Triton X-100 were examined in transmission electron micrographs of cell whole mounts and unembedded thick sections. The cytoskeleton, an ordered structure consisting of a peripheral plasma lamina, a complex network of filaments, and chromatin-containing nuclei, was revealed after extraction of intact cells with a nearly physiological buffer containing Triton X-100. The cytoskeleton was further fractionated by extraction with (NH4)2SO4, which left a structure enriched in intermediate filaments and desmosomes around the nuclei. A further digestion with nuclease and elution with (NH4)2SO4 removed the chromatin. The stable structure that remained after this procedure retained much of the epithelial morphology and contained essentially all of the cytokeratin filaments and desmosomes and the chromatin-depleted nuclear matrices. This structural network may serve as a scaffold for epithelial organization. The cytoskeleton and the underlying nuclear matrix intermediate filament scaffold, when examined in both conventional embedded thin sections and in unembedded whole mounts and thick sections, showed the retention of many of the detailed morphological aspects of the intact cells, which suggests a structural continuum linking the nuclear matrix, the intermediate filament network, and the intercellular desmosomal junctions. Most importantly, the protein composition of each of the four fractions obtained by this sequential procedure was essentially unique. Thus, the proteins constituting the soluble fraction, the cytoskeleton, the chromatin fraction, and the underlying nuclear matrix-intermediate filament scaffold are biochemically distinct.

Epithelial structure revealed by chemical dissection and unembedded electron microscopy

PubMed Central

Fey, E. G.; Capco, D. G.; Krochmalnic, G.; Penman, S.

1984-01-01

Cytoskeletal structures obtained after extraction of Madin-Darby canine kidney epithelial cell monolayers with Triton X-100 were examined in transmission electron micrographs of cell whole mounts and unembedded thick sections. The cytoskeleton, an ordered structure consisting of a peripheral plasma lamina, a complex network of filaments, and chromatin-containing nuclei, was revealed after extraction of intact cells with a nearly physiological buffer containing Triton X-100. The cytoskeleton was further fractionated by extraction with (NH4)2SO4, which left a structure enriched in intermediate filaments and desmosomes around the nuclei. A further digestion with nuclease and elution with (NH4)2SO4 removed the chromatin. The stable structure that remained after this procedure retained much of the epithelial morphology and contained essentially all of the cytokeratin filaments and desmosomes and the chromatin-depleted nuclear matrices. This structural network may serve as a scaffold for epithelial organization. The cytoskeleton and the underlying nuclear matrix intermediate filament scaffold, when examined in both conventional embedded thin sections and in unembedded whole mounts and thick sections, showed the retention of many of the detailed morphological aspects of the intact cells, which suggests a structural continuum linking the nuclear matrix, the intermediate filament network, and the intercellular desmosomal junctions. Most importantly, the protein composition of each of the four fractions obtained by this sequential procedure was essentially unique. Thus, the proteins constituting the soluble fraction, the cytoskeleton, the chromatin fraction, and the underlying nuclear matrix-intermediate filament scaffold are biochemically distinct. PMID:6540264

[Activation of the alternative oxidase of Yarrowia lipolytica by adenosine 5'-monophosphate].

PubMed

Medentsev, A G; Arinbasarova, A Iu; Smirnova, N M; Akimenko, V K

2004-01-01

The study of the effect of nucleoside phosphates on the activity of cyanide-resistant oxidase in the mitochondria and the submitochondrial particles of Yarrowia lipolytica showed that adenosine monophosphate (5'-AMP, AMP) did not stimulate the respiration of the intact mitochondria. The incubation of the mitochondria at room temperature (25 degrees C) for 3-5 h or their treatment with ultrasound, phospholipase A, and detergent Triton X-100 at a low temperature inactivated the cyanide-resistant alternative oxidase. The inactivated alternative oxidase could be reactivated by AMP. The reactivating effect of AMP was enhanced by azolectin. Some other nucleoside phosphates also showed reactivating ability in the following descending order. AMP = GMP > GDP > GTP > XMP > IMP. The apparent reaction rate constant Km for AMP upon the reactivation of the alternative oxidase of mitochondria treated with Triton X-100 or incubated at 25 degrees C was 12.5 and 20 microM, respectively. The Km for AMP upon the reactivation of the alternative oxidase of submitochondrial particles was 15 microM. During the incubation of yeast cells under conditions promoting the development of alternative oxidase, the content of adenine nucleotides (AMP, ADP, and ATP) in the cells and their respiration tended to decrease. The subsequent addition of cyanide to the cells activated their respiration, diminished the intracellular content of ATP three times, and augmented the content of AMP five times. These data suggest that the stimulation of cell respiration by cyanide may be due to the activation of alternative oxidase by AMP.

Research on Influencing Factors of Biological Filtration Tower Treating Toluene Gas

NASA Astrophysics Data System (ADS)

Zhang, Changping; Cao, Ziqing; Lu, Yuqi; Du, Linggai

2017-05-01

Through the orthogonal experimental design, the optimal combination of Triton X-100, nitrogen source, Fe2+, temperature, concentration of antibiotics, pH and spray quantity was determined with surfactants, nitrogen and iron elements as additive, by which the key influencing factors were determined. In the test, the removal efficiency of the second groups was higher than that of the eighth groups, which were 89% and 87%, respectively. The best combination of a group of removal was as follows: nitrogen source concentration was 2 g ·L-1, antibiotic concentration was 300 U·mL-1, the concentration of Triton X-100 was 0.05 mL·L-1, Fe2+ concentration was 14 mL·L-1, pH was 7, the temperature was 34°C, spray amount was 6 L ·h-1. The antibiotic concentration was the most important factor on the removal efficiency of the toluene. The concentration of gas in each layer of toluene was detected; the curve of the outlet concentration in the optimal combination and the average state was obtained. The removal efficiency of the optimal combination was much better than the average, and it was found that the removal rate decreased with the increase of the height of the filling layer. The change of oxygen content in each layer was detected which was no significant change. It showed that oxygen was not the limiting factor of the removal of toluene by microorganisms. Keywords: surfactants; biological filtration tower; toluene; orthogonal test

On the Automatic Decellularisation of Porcine Aortae: A Repeatability Study Using a Non-Enzymatic Approach.

PubMed

O'Connor Mooney, Rory; Davis, Niall Francis; Hoey, David; Hogan, Lisa; McGloughlin, Timothy M; Walsh, Michael T

2016-01-01

To investigate the repeatability of automatic decellularisation of porcine aortae using a non-enzymatic approach, addressing current limitations associated with other automatic decellularisation processes. Individual porcine aortae (n = 3) were resected and every third segment (n = 4) was allocated to one of three different groups: a control or a manually or automatically decellularised group. Manual and automatic decellularisation was performed using Triton X-100 (2% v/v) and sodium deoxycholate. Protein preservation and the elimination of a galactosyl-α(1,3)galactose (GAL) epitope were measured using immunohistochemistry and protein binding assays. The presence of residual DNA was determined with gel electrophoresis and spectrophotometry. Scaffold integrity was characterised with scanning electron microscopy and uni-axial tensile testing. Manual and automatic results were compared to one another, to control groups and to current gold standards. The results were comparable to those of current gold standard decellularisation techniques. Successful repeatability was achieved, both manually and automatically, with little effect on mechanical characteristics. Complete acellularity was not confirmed in either decellularisation group. Protein preservation was consistent in both the manually and automatically decellularised groups and between each individual aorta. Elimination of GAL was not achieved. Repeatable automatic decellularisation of porcine aortae is feasible using a Triton X-100-sodium deoxycholate protocol. Protein preservation was satisfactory; however, gold standard thresholds for permissible residual DNA levels were not achieved. Future research will focus on addressing this issue by optimisation of the existing protocol for thick tissues. © 2016 S. Karger AG, Basel.

Expression and Secretion of Endostar Protein by Escherichia Coli: Optimization of Culture Conditions Using the Response Surface Methodology.

PubMed

Mohajeri, Abbas; Abdolalizadeh, Jalal; Pilehvar-Soltanahmadi, Younes; Kiafar, Farhad; Zarghami, Nosratollah

2016-10-01

Endostar as a specific drug in treatment of the nonsmall cell lung cancer is produced using Escherichia coli expression system. Plackett-Burman design (PBD) and response surface methodology (RSM) are statistical tools for experimental design and optimization of biotechnological processes. This investigation aimed to predict and develop the optimal culture condition and its components for expression and secretion of endostar into the culture medium of E. coli. The synthetic endostar coding sequence was fused with PhoA signal peptide. The nine factors involved in the production of recombinant protein-postinduction temperature, cell density, rotation speed, postinduction time, concentration of glycerol, IPTG, peptone, glycine, and triton X-100-were evaluated using PBD. Four significant factors were selected based on PBD results for optimizing culture condition using RSM. Endostar was purified using cation exchange chromatography and size exclusion chromatography. The maximum level of endostar was obtained under the following condition: 13.57-h postinduction time, 0.76 % glycine, 0.7 % triton X-100, and 4.87 % glycerol. The predicted levels of endostar was significantly correlated with experimental levels (R 2 = 0.982, P = 0.00). The obtained results indicated that PBD and RSM are effective tools for optimization of culture condition and its components for endostar production in E. coli. The most important factors in the enhancement of the protein production are glycerol, glycine, and postinduction time.

Optode Membrane for Determination of Nicotine via Generation of Its Bromoethane Derivative.

PubMed

Choi, M M; Wu, X J; Li, Y R

1999-04-01

A plasticized poly(vinyl chloride) optode membrane incorporated with a valinomycin ionophore, a H(+)-selective chromoionophore (ETH 5294), and a lipophilic potassium tetrakis(4-chlorophenyl)borate was used as a reversible sensing device for the indirect optical determination of nicotine. Nicotine was extracted from a tobacco product (1-5 g) and converted to its bromoethane derivative (NBD(+)Br(-)) by reacting with a solution of bromoethane in ethanol. NBD(+)Br(-) in a solution of 0.05 M boric acid-Borax buffer and 0.2 mM Triton X-100 was extracted into the bulk of the membrane and subsequently caused changes in optical absorption of the sensing layer. The response slope, dynamic working range, detection limit, sensitivity, selectivity, effects of buffer solution and neutral surfactant Triton X-100, and lifetime were discussed in detail. The response was pH dependent. At pH 8.5, the detection range was extended from 0.4 μM to 1 mM. Typical response times (t(95)) of the samples were 2-4 min. The optode method was successfully used to detect nicotine in a tobacco sample from the market (average content 0.720%; RSD 0.044%; n = 11). The interference of K(+) on the optode method can be prevented by the pre-extraction procedure. Malic acid and citrate showed no interferences. The recovery of nicotine as NBD(+) was 84-119% in the range 0.035-5% nicotine. The result was satisfactory compared with an AOAC UV standard method.

Triton's Geyser-like Plumes

NASA Astrophysics Data System (ADS)

Brown, Robert H.; Soderblom, Laurence A.

In August of 1989, while flying by Neptune's largest satellite Triton, Voyager 2 made another of its stunning discoveries in its epic journey through the outer solar system. First seen by one of us (LAS) and Tammy Becker (also of the USGS), after stereoscopic examination of a group of images taken very near Voyager's closest approach to the satellite, were at least two, geyser-like plumes spewing almost perfectly vertical columns of material 1-km across roughly 8-km high into Triton's atmosphere; there the columns were sheared by stratospheric winds into 100-km-long, dark clouds thought to composed of condensed nitrogen mixed with organic particles. Triton's plumes may be the most unique of all the manifestations of geologic activity on satellites in the outer solar system in that their energy source may be sunlight trapped below Triton's surface in a so-called "solid-state greenhouse". This talk will focus on the physical characteristics of those plumes, and on the various mechanisms proposed to explain their presence and apparent persistence on Triton.

Bile salts stimulate mucin secretion by cultured dog gallbladder epithelial cells independent of their detergent effect.

PubMed

Klinkspoor, J H; Yoshida, T; Lee, S P

1998-05-15

1. Bile salts stimulate mucin secretion by the gallbladder epithelium. We have investigated whether this stimulatory effect is due to a detergent effect of bile salts. 2. The bile salts taurocholic acid (TC) and tauroursodeoxycholic acid (TUDC) and the detergents Triton X-100 (12.5-400 microM) and Tween-20 (0.1-3.2 mM) were applied to monolayers of cultured dog gallbladder epithelial cells. Mucin secretion was studied by measuring the secretion of [3H]N-acetyl-d-glucosamine-labelled glycoproteins. We also attempted to alter the fluidity of the apical membrane of the cells through extraction of cholesterol with beta-cyclodextrin (2.5-15 mM). The effect on TUDC-induced mucin secretion was studied. Cell viability was assessed by measuring lactate dehydrogenase (LDH) leakage or 51Cr release. 3. In contrast with the bile salts, the detergents were not able to cause an increase in mucin secretion without causing concomitant cell lysis. Concentrations of detergent that increased mucin release (>100 microM Triton X-100, >0.8 mM Tween-20), caused increased LDH release. Incubation with beta-cyclodextrin resulted in effective extraction of cholesterol without causing an increase in 51Cr release. However, no effect of the presumed altered membrane fluidity on TUDC (10 mM)-induced mucin secretion was observed. 4. The stimulatory effect of bile salts on mucin secretion by gallbladder epithelial cells is not affected by the fluidity of the apical membrane of the cells and also cannot be mimicked by other detergents. We conclude that the ability of bile salts to cause mucin secretion by the gallbladder epithelium is not determined by their detergent properties.

Simultaneous spectrophotometric determination of synthetic dyes in food samples after cloud point extraction using multiple response optimizations.

PubMed

Heidarizadi, Elham; Tabaraki, Reza

2016-01-01

A sensitive cloud point extraction method for simultaneous determination of trace amounts of sunset yellow (SY), allura red (AR) and brilliant blue (BB) by spectrophotometry was developed. Experimental parameters such as Triton X-100 concentration, KCl concentration and initial pH on extraction efficiency of dyes were optimized using response surface methodology (RSM) with a Doehlert design. Experimental data were evaluated by applying RSM integrating a desirability function approach. The optimum condition for extraction efficiency of SY, AR and BB simultaneously were: Triton X-100 concentration 0.0635 mol L(-1), KCl concentration 0.11 mol L(-1) and pH 4 with maximum overall desirability D of 0.95. Correspondingly, the maximum extraction efficiency of SY, AR and BB were 100%, 92.23% and 95.69%, respectively. At optimal conditions, extraction efficiencies were 99.8%, 92.48% and 95.96% for SY, AR and BB, respectively. These values were only 0.2%, 0.25% and 0.27% different from the predicted values, suggesting that the desirability function approach with RSM was a useful technique for simultaneously dye extraction. Linear calibration curves were obtained in the range of 0.02-4 for SY, 0.025-2.5 for AR and 0.02-4 μg mL(-1) for BB under optimum condition. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.009, 0.01 and 0.007 μg mL(-1) (n=10) for SY, AR and BB, respectively. The method was successfully used for the simultaneous determination of the dyes in different food samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Soaping the NMDA receptor: Various types of detergents influence differently [(3)H]MK-801 binding to rat brain membranes.

PubMed

Berger, Michael L

2016-01-01

Membranes prepared from rat brain were treated with increasing concentrations of cationic, neutral, anionic and zwitterionic surfactants. Potent inactivation of [(3)H]MK-801 binding to NMDA receptors (NRs) was provided by the cation cetyl pyridinium (IC50 25 μM) and the neutral digitonin (IC50 37 μM). A 2 h incubation of rat brain membranes at 24°C with 100 μM of the neutral Triton X-100 resulted in about 50% reversible inhibition (without inactivation). Reversible inhibition was also effected by the anion deoxycholate (IC50 700 μM), and by the zwitterions N-lauryl sulfobetaine (12-SB(±), 400 μM) and CHAPS (1.5 mM), with inactivation at higher concentrations. Keeping the NR cation channel in the closed state significantly protected against inactivation by cations and by 12-SB(±), but not by the other detergents. Inactivation depended differentially on the amount of the membranes, on the duration of the treatment, and on the temperature. Varying the amount of membranes by a factor 8 yielded for cetyl trimethylammonium (16-NMe3(+)) IC50s of inactivation from 10 to 80 μM, while for deoxycholate the IC50 of inactivation was 1.2 mM for all tissue quantities. Some compounds inactivated within a few min (16-NMe3(+), digitonin, CHAPS), while inactivation by others took at least half an hour (Triton X-100, deoxycholate, 12-SB(±)). These last 3 ones also exhibited the steepest temperature dependence. Knowledge about the influence of various parameters is helpful in selecting appropriate conditions allowing the treatment of brain membranes with amphiphiles without risking irreversible inactivation. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis of Mesoporous Nanocrystalline Zirconia by Surfactant-Assisted Hydrothermal Approach.

PubMed

Nath, Soumav; Biswas, Ashik; Kour, Prachi P; Sarma, Loka S; Sur, Ujjal Kumar; Ankamwar, Balaprasad G

2018-08-01

In this paper, we have reported the chemical synthesis of thermally stable mesoporous nanocrystalline zirconia with high surface area using a surfactant-assisted hydrothermal approach. We have employed different type of surfactants such as CTAB, SDS and Triton X-100 in our synthesis. The synthesized nanocrystalline zirconia multistructures exhibit various morphologies such as rod, mortar-pestle with different particle sizes. We have characterized the zirconia multistructures by X-ray diffraction study, Field emission scanning electron microscopy, Attenuated total refection infrared spectroscopy, UV-Vis spectroscopy and photoluminescence spectroscopy. The thermal stability of as synthesized zirconia multistructures was studied by thermo gravimetric analysis, which shows the high thermal stability of nanocrystalline zirconia around 900 °C temperature.

ISOZYMES OF ACID PHOSPHATASE IN NORMAL AND CALMETTE-GUÉRIN BACILLUS-INDUCED RABBIT ALVEOLAR MACROPHAGES

PubMed Central

Axline, S. G.

1968-01-01

The acid phosphatase activity of normal alveolar and BCG-induced alveolar macrophages has been examined. Five electrophoretically distinct forms of acid phosphatase have been identified in both normal and BCG-induced macrophages. The acid phosphatases can be divided into two major categories. One category, containing four distinct forms, is readily solubilized after repeated freezing and thawing or mechanical disruption The second category, containing one form, is firmly bound to the lysosomal membrane and can be solubilized by treatment of the lysosomal fraction with Triton X-100. The Triton-extractable acid phosphatase and the predominant aqueous soluble acid phosphatase have been shown to differ in the degree of membrane binding, in solubility, in net charge, and in molecular weight. The two pre-dominant phosphatases possess identical pH optimum and do not differ in response to enzyme inhibitors. BCG stimulation has been shown to result in a nearly twofold increase in acid phosphatase activity. A nearly proportionate increase in the major acid phosphatase forms has been observed. PMID:4878908

The impact of surfactants on Fe(III)-TAML-catalyzed oxidations by peroxides: accelerations, decelerations, and loss of activity.

PubMed

Banerjee, Deboshri; Apollo, Frank M; Ryabov, Alexander D; Collins, Terrence J

2009-10-05

Iron(III) complexes of tetraamidato macrocyclic ligands (TAMLs), [Fe{4-XC(6)H(3)-1,2-(NCOCMe(2)NCO)(2)CR(2)}(OH(2))](-), 1 (1 a: X = H, R = Me; 1 b: X = COOH, R = Me); 1 c: X = CONH(CH(2))(2)COOH, R = Me; 1 d: CONH(CH(2))(2)NMe(2), R = Me; 1 e: X = CONH(CH(2))(2)NMe(3) (+), R = Me; 1 f: X = H, R = F), have been tested as catalysts for the oxidative decolorization of Orange II and Sudan III dyes by hydrogen peroxide and tert-butyl hydroperoxide in the presence of micelles that are neutral (Triton X-100), positively charged (cetyltrimethylammonium bromide, CTAB), and negatively charged (sodium dodecyl sulfate, SDS). The previously reported mechanism of catalysis involves the formation of an oxidized intermediate from 1 and ROOH (k(I)) followed by dye bleaching (k(II)). The micellar effects on k(I) and k(II) have been separately studied and analyzed by using the Berezin pseudophase model of micellar catalysis. The largest micellar acceleration in terms of k(I) occurs for the 1 a-tBuOOH-CTAB system. At pH 9.0-10.5 the rate constant k(I) increased by approximately five times with increasing CTAB concentration and then gradually decreased. There was no acceleration at higher pH, presumably owing to the deprotonation of the axial water ligand of 1 a in this pH range. The k(I) value was only slightly affected by SDS (in the oxidation of Orange II), but was strongly decelerated by Triton X-100. No oxidation of the water-insoluble, hydrophobic dye Sudan III was observed in the presence of the SDS micelles. The k(II) value was accelerated by cationic CTAB micelles when the hydrophobic primary oxidant tert-butyl hydroperoxide was used. It is hypothesized that tBuOOH may affect the CTAB micelles and increase the binding of the oxidized catalysts. The tBuOOH-CTAB combination accelerated both of the catalysis steps k(I) and k(II).

X-ray crystallographic and MD simulation studies on the mechanism of interfacial activation of a family I.3 lipase with two lids.

PubMed

Angkawidjaja, Clement; Matsumura, Hiroyoshi; Koga, Yuichi; Takano, Kazufumi; Kanaya, Shigenori

2010-07-02

The interfacial activation mechanism of family I.3 lipase from Pseudomonas sp. MIS38 (PML), which has two alpha-helical lids (lid1 and lid2), was investigated using a combination of X-ray crystallography and molecular dynamics (MD) simulation. The crystal structure of PML in an open conformation was determined at 2.1 A resolution in the presence of Ca(2+) and Triton X-100. Comparison of this structure with that in the closed conformation indicates that both lids greatly change their positions and lid1 is anchored by the calcium ion (Ca1) in the open conformation. This structure was not seriously changed even when the protein was dialyzed extensively against the Ca(2+)-free buffer containing Triton X-100 before crystallization, indicating that the open conformation is fairly stable unless a micellar substance is removed. The crystal structure of the PML derivative, in which the active site serine residue (Ser207) is diethylphosphorylated by soaking the crystal of PML in the open conformation in a solution containing diethyl p-nitrophenyl phosphate, was also determined. This structure greatly resembles that in the open conformation, indicating that PML structure in the open conformation represents that in the active form. MD simulation of PML in the open conformation in the absence of micelles showed that lid2 closes first, while lid1 maintains its open conformation. Likewise, MD simulation of PML in the closed conformation in the absence of Ca(2+) and in the presence of octane or trilaurin micelles showed that lid1 opens, while lid2 remains closed. These results suggest that Ca1 functions as a hook for stabilization of a fully opened conformation of lid1 and for initiation of subsequent opening of lid2. Copyright 2010 Elsevier Ltd. All rights reserved.

Bacteriocin production by Pediococcus pentosaceus isolated from marula (Scerocarya birrea).

PubMed

Todorov, Svetoslav D; Dicks, Leon M T

2009-06-30

Strain ST44AM, isolated from marula, was identified as Pediococcus pentosaceus based on biochemical tests, sugar fermentation reactions (API 50CHL), PCR with species-specific primers and 16S rDNA sequencing. Strain ST44AM produces a 6.5 kDa class IIa bacteriocin, active against lactic acid bacteria, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Listeria innocua, Listeria ivanovii subsp. ivanovii and Listeria monocytogenes. The peptide is inactivated by proteolytic enzymes, but not when treated with alpha-amylase, Triton X-100, Triton X-114, SDS, Tween 20, Tween 80, urea, NaCl and EDTA. No change in activity was recorded after 2 h at pH values between 2.0 and 12.0, and after treatment at 100 degrees C for 120 min or 121 degrees C for 20 min. The mode of activity against L. ivanovii susbp. ivanovii ATCC19119 and Enterococcus faecium HKLHS is bactericidal, resulting in cell lyses and enzyme- and DNA-leakage. No significant differences in cell growth and bacteriocin production were observed when strain ST44AM was cultured in MRS broth at 26 degrees C, 30 degrees C and 37 degrees C for 24 h and tested against the same target strain. L. ivanovii subsp. ivanovii ATCC 19119 and E. faecium HKLHS did, however, differ in sensitivity to bacteriocin ST44AM (3.3x10(6) AU/mL and 2.6x10(4) AU/mL, respectively). Peptide ST44AM adsorbs at high levels (1600 AU/mL) to producer cells. Bacteriocin ST44AM may be a derivative of pediocin PA-1. This is the first report on the presence of P. pentosaceus in marula and a pediocin PA-1 derivative produced by this species. We are also the first to report on the synergetic effect ciprofloxacin has on a pediocin-like bacteriocin.

Highly efficient micellar extraction of toxic picric acid into novel ionic liquid: Effect of parameters, solubilization isotherm, evaluation of thermodynamics and design parameters.

PubMed

Bhatt, Darshak R; Maheria, Kalpana C; Parikh, Jigisha K

2015-12-30

A simple and new approach in cloud point extraction (CPE) method was developed for removal of picric acid (PA) by the addition of N,N,N,N',N',N'-hexaethyl-ethane-1,2-diammonium dibromide ionic liquid (IL) in non-ionic surfactant Triton X-114 (TX-114). A significant increase in extraction efficiency was found upon the addition of dicationic ionic liquid (DIL) at both nearly neutral and high acidic pH. The effects of different operating parameters such as pH, temperature, time, concentration of surfactant, PA and DIL on extraction of PA were investigated and optimum conditions were established. The extraction mechanism was also proposed. A developed Langmuir isotherm was used to compute the feed surfactant concentration required for the removal of PA up to an extraction efficiency of 90%. The effects of temperature and concentration of surfactant on various thermodynamic parameters were examined. It was found that the values of ΔG° increased with temperature and decreased with surfactant concentration. The values of ΔH° and ΔS° increased with surfactant concentration. The developed approach for DIL mediated CPE has proved to be an efficient and green route for extraction of PA from water sample. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization and membrane organization of beta 1----3- and beta 1----4-galactosyltransferases from human colonic adenocarcinoma cell lines Colo 205 and SW403: basis for preferential synthesis of type 1 chain lacto-series carbohydrate structures.

PubMed

Holmes, E H

1989-05-01

Evidence indicates that activation of a beta 1----3N-acetylglucosaminyltransferase is responsible for accumulation of large quantities of lacto-series tumor-associated antigens in human colonic adenocarcinomas. Expression of type 1 and 2 core chain derivatives characterize human colonic adenocarcinomas, whereas normal adult colonic epithelial cells express detectable quantities of only type 1 chain derivatives. The basis for preferential synthesis of type 1 chain lacto-series carbohydrate structures characteristic of normal colonic mucosa and human colonic adenocarcinoma Colo 205 cells has been studied. The beta 1----3- and beta 1----4galactosyltransferase enzymes associated with synthesis of type 1 and 2 core chain structures, respectively, have been separated from a Triton X-100 solubilized membrane fraction of Colo 205 cells by chromatography on an alpha-lactalbumin-Sepharose column and their properties studied. Optimal transfer of beta 1----3-linked galactose to acceptor Lc3 occurred in the presence of 0.1% Triton CF-54 with Triton X-100 providing 75% of maximal activity. The enzyme was active over a broad pH range from 6.5 to 7.5 and had a near absolute requirement for Mn2+. The Km values for donor UDPgalactose and acceptor Lc3 were determined to be 48 and 13 microM, respectively. In contrast, the beta 1----4galactosyltransferase required taurodeoxycholate for maximal activity and the Km for Lc3 was found to be 20-fold higher than that for the beta 1----3-specific enzyme under the same assay conditions. Studies with membrane-bound beta 1----3- and beta 1----4galactosyltransferases as found in Golgi-rich membrane fractions of SW403 and Colo 205 adenocarcinoma cells showed that preferential synthesis of type 1 chain structures occurs under conditions similar to those in vivo for biosynthesis of lacto-series core chains. The results suggest that both the higher affinity of the beta 1----3galactosyltransferase for acceptor Lc3 and the membrane organizational features result in preferential synthesis of type 1 chain structures.

Cellulase and cell differentiation in Acer pseudoplatanus.

PubMed

Sheldrake, A R

1970-06-01

Homogenates of differentiating xylem and phloem tissue have higher cellulase activities than cambial samples; the highest activity is always found in phloem. Callus tissue, in which no vascular differentiation occurs, contains only low cellulase activity. The results suggest that cellulase is involved in vascular differentiation. Different pH optima of cellulase activity were found: in cambium, xylem and phloem tissue, cellulase activity with an optimum at about pH 5.9 is predominantly membrane-bound; it is sedimentable at 100,000 g and releasable by Triton X-100. The same may be true of activity with an optimum at pH 5.3. Phloem tissue also contains a soluble, cytoplasmic cellulase of high activity at pH 7.1, and xylem tissue contains cytoplasmic cellulase with an optimum at pH 6.5. Low cellulase activity with a pH optimum similar to that of xylem homogenates was found in xylem sap. Cellulase activity in abscission zones increases greatly just before leaf abscission. Abscission zone cellulase has two pH optima, et 5.3 and 5.9; both activities are increased by Triton treatment of homogenates. The possible existence of several different cellulases forming part of a cellulase complex, and the rôle of the enzymes in hydrolysing wall material during cell differentiation are discussed.

Kinetic characterization of Escherichia coli outer membrane phospholipase A using mixed detergent-lipid micelles.

PubMed

Horrevoets, A J; Hackeng, T M; Verheij, H M; Dijkman, R; de Haas, G H

1989-02-07

The substrate specificity of Escherichia coli outer membrane phospholipase A was analyzed in mixed micelles of lipid with deoxycholate or Triton X-100. Diglycerides, monoglycerides, and Tweens 40 and 85 in Triton X-100 are hydrolyzed at rates comparable to those of phospholipids and lysophospholipids. p-Nitrophenyl esters of fatty acids with different chain lengths and triglycerides are not hydrolyzed. The minimal substrate characteristics consist of a long acyl chain esterified to a more or less hydrophilic headgroup as is the case for the substrate monopalmitoylglycol. Binding occurs via the hydrocarbon chain of the substrate; diacyl compounds are bound three to five times better than monoacyl compounds. When acting on lecithins, phospholipase A1 activity is six times higher than phospholipase A2 activity or 1-acyl lysophospholipase activity. Activity on the 2-acyl lyso compound is about two times less than that on the 1-acyl lysophospholipid. The enzyme therefore has a clear preference for the primary ester bond of phospholipids. In contrast to phospholipase A1 activity, phospholipase A2 activity is stereospecific. Only the L isomer of a lecithin analogue in which the primary acyl chain was replaced by an alkyl ether group is hydrolyzed. The D isomer of this analogue is a competitive inhibitor, bound with the same affinity as the L isomer. On these ether analogues the enzyme shows the same preference for the primary acyl chain as with the natural diester phospholipids. Despite its broad specificity, the enzyme will initially act as a phospholipase A1 in the E. coli envelope where it is embedded in phospholipids.

Decellularization of Human Nasal Septal Cartilage for the Novel Filler Material of Vocal Fold Augmentation.

PubMed

Kang, Dae-Woon; Shin, Sung-Chan; Jang, Jeon-Yeob; Park, Hee-Young; Lee, Jin-Choon; Wang, Soo-Geun; Lee, Byung-Joo

2017-01-01

The clinical application of allogenic and/or xenogenic cartilage for vocal fold augmentation requires to remove the antigenic cellular component. The objective of this study was to assess the effect of cartilage decellularization and determine the change in immunogenicity after detergent treatment in human nasal septal cartilage flakes made by the freezing and grinding method. Human nasal septal cartilages were obtained from surgical cases. The harvested cartilages were treated by the freezing and grinding technique. The obtained cartilage flakes were treated with 1% Triton X-100 or 2% sodium dodecyl sulfate (SDS) for decellularization of the cartilage flakes. Hematoxylin and eosin stain (H&E stain), surface electric microscopy, immunohistochemical stain for major histocompatibility complex I and II, and ELISA for DNA contents were performed to assess the effect of cartilage decellularization after detergent treatment. A total of 10 nasal septal cartilages were obtained from surgical cases. After detergent treatment, the average size of the cartilage flakes was significantly decreased. With H&E staining, the cell nuclei of decellularized cartilage flakes were not observed. The expression of major histocompatibility complex (MHC)-I and II antigens was not identified in the decellularized cartilage flakes after treatment with detergent. DNA content was removed almost entirely from the decellularized cartilage flakes. Treatment with 2% SDS or 1% Triton X-100 for 1 hour appears to be a promising method for decellularization of human nasal septal cartilage for vocal fold augmentation. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

The muscle protein dysferlin accumulates in the Alzheimer brain

PubMed Central

Palamand, Divya; Strider, Jeff; Milone, Margherita; Pestronk, Alan

2006-01-01

Dysferlin is a transmembrane protein that is highly expressed in muscle. Dysferlin mutations cause limb-girdle dystrophy type 2B, Miyoshi myopathy and distal anterior compartment myopathy. Dysferlin has also been described in neural tissue. We studied dysferlin distribution in the brains of patients with Alzheimer disease (AD) and controls. Twelve brains, staged using the Clinical Dementia Rating were examined: 9 AD cases (mean age: 85.9 years and mean disease duration: 8.9 years), and 3 age-matched controls (mean age: 87.5 years). Dysferlin is a cytoplasmic protein in the pyramidal neurons of normal and AD brains. In addition, there were dysferlin-positive dystrophic neurites within Aβ plaques in the AD brain, distinct from tau-positive neurites. Western blots of total brain protein (RIPA) and sequential extraction buffers (high salt, high salt/Triton X-100, SDS and formic acid) of increasing protein extraction strength were performed to examine solubility state. In RIPA fractions, dysferlin was seen as 230–272 kDa bands in normal and AD brains. In serial extractions, there was a shift of dysferlin from soluble phase in high salt/Triton X-100 to the more insoluble SDS fraction in AD. Dysferlin is a new protein described in the AD brain that accumulates in association with neuritic plaques. In muscle, dysferlin plays a role in the repair of muscle membrane damage. The accumulation of dysferlin in the AD brain may be related to the inability of neurons to repair damage due to Aβ deposits accumulating in the AD brain. PMID:17024495

Platelet adhesion in breast cancer: development and application of a novel assay.

PubMed

Caine, Graham J; Nadar, Sunil K; Lip, Gregory Y H; Stonelake, Paul S; Blann, Andrew D

2004-09-01

The increased risk of thromboembolism in cancer may be related to a prothrombotic or hypercoagulable state, with abnormalities of haemostasis and platelet activation. To further investigate the role of platelets in this disease, we developed and applied a new assay to detect and quantify platelet adhesion to the well-defined subendothelial substrate, fibrinogen. Platelet-rich plasma was obtained from 31 females with breast cancer (13 metastatic, 18 benign), and 30 healthy female controls, re-suspended to 2 x 10(8) cells/ml and 100 microl and incubated for 1 h in microtitre plates pre-coated with fibrinogen (5 mg/ml). The supernatant was carefully aspirated, lysed with Triton X-100 and stored at -70 degrees C as supernatant-platelet lysate. The microtitre wells were carefully washed with saline, bound platelets lysed with Triton, and the lysate stored at -70 degrees C as bound-platelet lysate. P-selectin was determined in supernatant-platelet lysate and bound-platelet lysate for each patient by enzyme-linked immunosorbent assay. Interpreting differences in P-selectin in different lysates as reflective of adhesion, patients with cancer had increased platelet adhesion (absolute and percentage, both P < 0.001) compared with healthy controls. There was also more adhesion (P < 0.001) in metastatic disease compared with non-metastatic disease. Patients with breast carcinomas, and, in particular, those with metastatic disease, have a higher degree of platelet adhesion, which may by quantified by a novel method based on cell lysis. This increase in platelet adhesiveness may be related to an increased risk of thromboembolism in these patients.

Application of Optimized Vortex-Assisted Surfactant-Enhanced DLLME for Preconcentration of Thymol and Carvacrol, and Their Determination by HPLC-UV: Response Surface Methodology.

PubMed

Ghaedi, Mehrorang; Roosta, Mostafa; Khodadoust, Saeid; Daneshfar, Ali

2015-08-01

A novel vortex-assisted surfactant-enhanced dispersive liquid-liquid microextraction combined with high-performance liquid chromatography (VASEDLLME-HPLC) was developed for the determination of thymol and carvacrol (phenolic compound). In this method, the extraction solvent (CHCl3) was dispersed into the aqueous samples via a vortex agitator and addition of the surfactant (Triton X-100). The preliminary experiments were undertaken to select the best extraction solvent and surfactant. The influences of effective variables were investigated using a Plackett-Burman 2(7-4) screening design and then, the significant variables were optimized by using a central composite design combined with desirability function. Working under optimum conditions specified as: 140 µL CHCl3, 0.08% (w/v, Triton X-100), 3 min extraction time, 6 min centrifugation at 4,500 rpm, pH 7, 0.0% (w/v) NaCl permit achievement of high and reasonable linear range over 0.005-4.0 mg L(-1) with R(2) = 0.9998 (n = 10). The separation of thymol and carvacrol was achieved in <14 min using a C18 column and an isocratic binary mobile phase acetonitrile-water (55:45, v/v) with a flow rate of 1.0 mL min(-1). The VASEDLLME is applied for successful determination of carvacrol and thymol in different thyme and pharmaceutical samples with relative standard deviation <4.7% (n = 5). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Immobilization of fungal laccase onto a nonionic surfactant-modified clay material: application to PAH degradation.

PubMed

Chang, Yi-Tang; Lee, Jiunn-Fwu; Liu, Keng-Hua; Liao, Yi-Fen; Yang, Vivian

2016-03-01

Nonionic surfactant-modified clay is a useful absorbent material that effectively removes hydrophobic organic compounds from soil/groundwater. We developed a novel material by applying an immobilized fungal laccase onto nonionic surfactant-modified clay. Low-water-solubility polycyclic aromatic hydrocarbons (PAHs) (naphthalene/phenanthrene) were degraded in the presence of this bioactive material. PAH degradation by free laccase was higher than degradation by immobilized laccase when the surfactant concentration was allowed to form micelles. PAH degradation by immobilized laccase on TX-100-modified clay was higher than on Brij35-modified clay. Strong laccase degradation of PAH can be maintained by adding surfactant monomers or micelles. The physical adsorption of nonionic surfactants onto clay plays an important role in PAH degradation by laccase, which can be explained by the structure and molecular interactions of the surfactant with the clay and enzyme. A system where laccase is immobilized onto TX-100-monomer-modified clay is a good candidate bioactive material for in situ PAHs bioremediation.

Evaluation of Ebola virus inactivation procedures for Plasmodium falciparum malaria diagnostics.

PubMed

Lau, Rachel; Wang, Amanda; Chong-Kit, Ann; Ralevski, Filip; Boggild, Andrea K

2015-04-01

Plasmodium falciparum malaria is highly endemic in the three most affected countries in the current epidemic of Ebola virus disease (EVD) in West Africa. As EVD and malaria are clinically indistinguishable, both remain part of the differential diagnosis of ill travelers from returning from areas of EVD transmission. We compared the performances of a rapid diagnostic test (BinaxNOW) and real-time PCR with P. falciparum-positive specimens before and after heat and Triton X-100 inactivation, and we documented no loss of sensitivity. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Conversion of Signals from Ion-specific Electrodes to Linear Concentrations 1

PubMed Central

Heath, Robert L.

1975-01-01

This paper describes the assembly (from commercially available components) of an antilog converter, which transforms the output signals of ion-specific electrodes to ionic concentrations suitable for a linear recorder. It responds linearly to cation concentrations from 10 μm to at least 10 mm and can be used for electrodes kept at any temperatures (0 to 50 C). The leakage of K+ from a unicellular algae (Chlorella sorokiniana) can be induced by Triton X-100, heating, or suspension in a tris buffer and is used to demonstrate the operation of this device. PMID:16659270

Localisation and semi-quantitative measurement of lipocortin 1 in rat anterior pituitary cells by fluorescence-activated cell analysis/sorting and electron microscopy.

PubMed

Christian, H C; Flower, R J; Morris, J F; Buckingham, J C

1999-09-01

Lipocortin 1 (LC1, also called annexin 1), a Ca2(+)- and phospholipid-binding protein, is an important mediator of glucocorticoid action in the anterior pituitary gland. Previous studies based on immunoprecipitation and Western blot analysis suggest that LC1 is found intracellularly both in the cytoplasm and in association with membranes and also on the cell surface where it attaches to the membrane by a Ca2(+)-dependent mechanism. However, as yet it is unclear which anterior pituitary cell types express the protein. Accordingly, we have developed a method based on a combination of fluorescence activated cell (FAC) analysis/sorting and electron microscopy to detect and quantify intracellular LC1 in rat anterior pituitary cells and to identify the cell types in which it is expressed. In addition, we have measured cell surface LC1 and examined the influence of glucocorticoids on the cellular disposition of the protein. Anterior pituitary cells were dispersed with collagenase. For experiments measuring intracellular LC1, three cell fixation/permeabilisation methods were examined initially, i.e. (1) Zamboni's fluid (30 min) and Triton-X-100 (0.12%, 1 or 12 h); (2) paraformaldehyde (2%, 1 h) and Triton-X-100 (0.2%, 10 min); and (3) paraformaldehyde (0.2%, 15 min) and saponin (0.1%, 5 min). The protocol using paraformaldehyde/Triton-X-100 provided optimal preservation of cell ultrastructure and of LC1 immunoreactivity (ir-LC1) while also effectively permeabilising the cells; it was therefore used in subsequent studies. Using an anti-LC1 monoclonal antibody as a probe, 82+/-5% of the secretory cells in the heterogeneous anterior pituitary cell preparation were shown by FAC analysis to display specific fluorescence for intracellular ir-LC1. Morphological analysis and immunogold-histochemistry of cells separated by FAC sorting identified corticotrophs, lactotrophs, somatotrophs and gonadotrophs in the population displaying LC1 immunofluorescence. LC1 was also detected on the surface of anterior pituitary cells by FACS analysis. Incubation of anterior pituitary cells with dexamethasone or corticosterone (0.1 and 1.0 microM) prior to fixation and analysis produced a significant, concentration-dependent decrease in intracellular ir-LC1 and a concomitant increase in the amount of ir-LC1 detected on the surface of the cells; the effects of the two steroids were indistinguishable quantitatively. In conclusion, we report a novel method which permits (1) the detection and semi-quantitative measurement of intracellular and surface LC1 in anterior pituitary cells; and (2) the identification of the cell types in which the protein is found.

Production of lipase and protease from an indigenous Pseudomonas aeruginosa strain and their evaluation as detergent additives: compatibility study with detergent ingredients and washing performance.

PubMed

Grbavčić, Sanja; Bezbradica, Dejan; Izrael-Živković, Lidija; Avramović, Nataša; Milosavić, Nenad; Karadžić, Ivanka; Knežević-Jugović, Zorica

2011-12-01

An indigenous Pseudomonas aeruginosa strain has been studied for lipase and protease activities for their potential application in detergents. Produced enzymes were investigated in order to assess their compatibility with several surfactants, oxidizing agents and commercial detergents. The crude lipase appeared to retain high activity and stability in the presence of several surfactants and oxidizing agents and it was insusceptible to proteolysis. Lutensol® XP80 and Triton® X-100 strongly activated the lipase for a long period (up to 40 and 30% against the control after 1h) while the protease activity was enhanced by the addition of Triton® WR1339 and Tween® 80. The washing performance of the investigated surfactants was significantly improved with the addition of the crude enzyme preparation. Studies were further undertaken to improve enzymes production. The optimization of fermentation conditions led to an 8-fold increase of lipase production, while the production of protease was enhanced by 60%. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaluation of toxic agent effects on lung cells by fiber evanescent wave spectroscopy.

PubMed

Lucas, Pierre; Le Coq, David; Juncker, Christophe; Collier, Jayne; Boesewetter, Dianne E; Boussard-Plédel, Catherine; Bureau, Bruno; Riley, Mark R

2005-01-01

Biochemical changes in living cells are detected using a fiber probe system composed of a single chalcogenide fiber acting as both the sensor and transmission line for infrared optical signals. The signal is collected via evanescent wave absorption along the tapered sensing zone of the fiber. We spectroscopically monitored the effects of the surfactant Triton X-100, which serves as a toxic agent simulant on a transformed human lung carcinoma type II epithelial cell line (A549). We observe spectral changes between 2800-3000 cm(-1) in four absorptions bands, which are assigned to hydrocarbon vibrations of methylene and methyl groups in membrane lipids. Comparison of fiber and transmission spectra shows that the present technique allows one to locally probe the cell plasma membrane in the lipid spectral region. These optical responses are correlated with cellular metabolic activity measurements and LDH (lactate dehydrogenase) release assays that indicate a loss of cellular function and membrane integrity as would be expected in response to the membrane solubilizing Triton. The spectroscopic technique shows a significantly greater detection resolution in time and concentration.

[Study on solid phase extraction spectrophotometric determination of zinc with 2-(2-quinolylazo)-5-dimthylaminophenol].

PubMed

Zhou, Shi-ping; Duan, Chang-qun; Liu, Hong-cheng; Hu, Qiu-fen

2005-10-01

A highly sensitive, selective and rapid method for the determination of zinc based on the rapid reaction of zinc(II) with 2-(2-quinolylazo)-5-dimthylaminophenol (QADMAP) and the solid phase extraction of zinc ion with anion exchange resin cartridge was developed. In the presence of pH 8.5 buffer solution and Triton X-100 medium, QADMAP can react with zinc(II) to form a stable 2 :1 complex (QADMAP:Zn(II)). The molar absorptivity is 1.22 x 10(5)L x moL(-1) x cm(-1) at 590 nm. Beer's law is obeyed in the range of 0-1.0 microg x mL(-1). The zinc ions in the samples can be enriched and separated by solid phase extraction with anion exchange resincartridge. Testing results show that recovery for zinc(II) was from 95% to 104%, and RSD was below 3%. This method was applied to the determination of zinc in water and food with good results.

Activation of polyphenol oxidase in extracts of bran from several wheat (Triticum aestivum) cultivars using organic solvents, detergents, and chaotropes.

PubMed

Okot-Kotber, Moses; Liavoga, Allan; Yong, Kwon-Joong; Bagorogoza, Katherine

2002-04-10

Polyphenol oxidase (PPO), known to induce browning in wheat-based products, has been shown to be activatable in wheat (Triticum aestivum) bran extracts by chemical compounds. The activity in the extracts could be increased to varying degrees with acetone, methanol, ethanol, 2-propanol, and n-butanol as additives in the extraction buffer. The most potent alcoholic activator was n-butanol (about a 3-fold increase), followed by 2-propanol and ethanol, whereas methanol had the least effect. Ionic detergents in the extraction buffer were also good activators, with sodium dodecyl sulfate (SDS) being more potent (3-fold increase) than cetyltrimethylammonium bromide (CTAB) that had only half as much effect, whereas the nonionic detergent, Triton X-114, was ineffective. The chaotropes, urea and guanidine x HCl (GND), were the most potent activators of all, increasing the activity over 4-fold. Of the two chaotropes, GND was more effective at lower concentrations (<6 M) than urea. However, the enzyme activity lessened at a higher concentration of GND (6 M), while there was a further increase in the activity with 6 M urea treatment. The activity lessened with higher concentration of GND presumably as a result of extensive denaturation of the enzyme, as GND is known to be a more potent denaturant than urea. It is hypothesized that in wheat PPO exists in an inactive form which may be activated by the presence of activators, hitherto unknown, similar in effect to that elicited by the chemical denaturants in this study.

Voyager IRIS Measurements of Triton's Thermal Emission: Impllications for Pluto?

NASA Astrophysics Data System (ADS)

Stansberry, John A.; Spencer, John; Linscott, Ivan

2015-11-01

The New Horizons Pluto encounter data set includes unique observations obtained using the Radio Science experiment to measure the night-side thermal emission at centimeter wavelengths, well beyond the emission peak (in the 70 to 100 micron range). 26 years ago the Voyager 2 Infrared Interferometer Spectrometer (IRIS) obtained spectra in the 30 - 50 micron wavelength range to try and detect thermal emission from Pluto's sibling, Triton. Conrath etal. (1989) analyzed 16 of the IRIS spectra of Triton's dayside and derived a weak limit of 36 K - 41 K. We have analysed those, and an additional 75 spectra, to refine the limits on the temperature of Triton's surface, and to explore diurnal differences in the thermal emission. Triton results from other Voyager instruments provide important constraints on our interpretation of the IRIS data, as do Spitzer measurements of Pluto's thermal emission.For unit-emissivity, average temperature is 34 K, inconsistent with the pressure of Triton's atmosphere (13 - 19 microbar), the presence of beta-phase nitrogen ice on the surface, and the likely presence ofwarm regions on the surface. The atmospheric pressure requires nitrogen ice temperatures of 37.4 K - 38.1 K, which in turn requires emissivity of 0.31--0.53. Such a low emissivity in this spectral region might be expected if the surface is dominated by nitrogen or methane ice. Averages of data subsets show evidence for brightness temperature variations across Triton's surface. Surprisingly, the data seem to indicate that Triton's nightside equatorial region was warmer than on the dayside.These Voyager results for Triton provide a useful context for interpreting New Horizons and ALMA observations of emission from Pluto in the sub-millimeter and centimeter region. JWST will be capable of detecting Triton's and Pluto's 10 - 28 micron thermal emission, although scattered light from Neptune may be an issue for the Triton. Combined with new capabilities of ALMA to measure the sub-millimeter emission (and even resolve the disks of Pluto and Triton), it seems possible that we may gain significant new insights into the thermal properties of these bodies in the coming decade.

An oxidant- and solvent-stable protease produced by Bacillus cereus SV1: application in the deproteinization of shrimp wastes and as a laundry detergent additive.

PubMed

Manni, Laila; Jellouli, Kemel; Ghorbel-Bellaaj, Olfa; Agrebi, Rym; Haddar, Anissa; Sellami-Kamoun, Alya; Nasri, Moncef

2010-04-01

The current increase in amount of shrimp wastes produced by the shrimp industry has led to the need in finding new methods for shrimp wastes disposal. In this study, an extracellular organic solvent- and oxidant-stable metalloprotease was produced by Bacillus cereus SV1. Maximum protease activity (5,900 U/mL) was obtained when the strain was grown in medium containing 40 g/L shrimp wastes powder as a sole carbon source. The optimum pH, optimum temperature, pH stability, and thermal stability of the crude enzyme preparation were pH 8.0, 60 degrees C, pH 6-9.5, and <55 degrees C, respectively. The crude protease was extremely stable toward several organic solvents. No loss of activity was observed even after 60 days of incubation at 30 degrees C in the presence of 50% (v/v) dimethyl sulfoxide and ethyl ether; the enzyme retained more than 70% of its original activity in the presence of ethanol and N,N-dimethylformamide. The protease showed high stability toward anionic (SDS) and non-ionic (Tween 80, Tween 20, and Triton X-100) surfactants. Interestingly, the activity of the enzyme was significantly enhanced by oxidizing agents. In addition, the enzyme showed excellent compatibility with some commercial liquid detergents. The protease of B. cereus SV1, produced under the optimal culture conditions, was tested for shrimp waste deproteinization in the preparation of chitin. The protein removal with a ratio E/S of 20 was about 88%. The novelties of the SV1 protease include its high stability to organic solvents and surfactants. These unique properties make it an ideal choice for application in detergent formulations and enzymatic peptide synthesis. In addition, the enzyme may find potential applications in the deproteinization of shrimp wastes to produce chitin.

Functional domains of the T lymphocyte plasma membrane: characterization of the polypeptide composition.

PubMed

Szamel, M; Kaever, V; Resch, K

1987-01-01

Highly purified plasma membranes from calf thymocytes were fractionated by affinity chromatography on Concanavalin A-Sepharose into two subfractions, one eluting freely from the affinity column (MF1) and a second being specifically retained (MF2). SDS-polyacrylamide-gel-electrophoresis revealed different polypeptide patterns of the two plasma membrane subfractions. Polypeptides of apparent molecular weights of 170, 150, 110, 94, 39, and 30 kDa were several-fold enriched in the adherent fraction, MF2. In contrast, several proteins in the 55-65 kDa range were preferentially recovered in the non-adherent fraction. Five Five of the six polypeptides, preferentially recovered in MF2 proved to be glycoproteins, the 39 kDa peptide was non-glycosilated. The differences in the amounts of the polypeptides specifically enriched in the adherent fraction MF2 became even more clear-cut when plasma membranes solubilized with non-ionic detergents (lysolecithin, ET-18-2H, Triton-X-100) were separated by affinity chromatography on Concanavalin A-Sepharose. The non-glycosilated peptide of apparent molecular weight of 39 kDa was recovered together with several glycoproteins in the adherent fraction, MF2, suggesting that not single glycoproteins, but plasma membrane domains were separated by Concanavalin A-Sepharose. Although the glycoproteins of the non-adherent fraction MF1 bound significant amounts of Concanavalin A, the major Concanavalin A binding glycoproteins were recovered in the adherent fraction, MF2. The plasma membrane subfractions showed also different functional properties, the specific activities [Na+ + K+]AT-Pase, Ca2+ ATPase and lysolecithin acyltransferase were several-fold enriched in the adherent fraction, MF2, as compared to MF1. The data suggest the existence of plasma membrane domains in the plasma membranes of thymocytes consisting of a different set of proteins, among others the major Concanavalin A binding glycoproteins with some membrane bound enzymes, probably implicated in the initiation of lymphocyte activation.

Transcriptional and Functional Analysis of the Effects of Magnolol: Inhibition of Autolysis and Biofilms in Staphylococcus aureus

PubMed Central

Liang, Junchao; Shen, Fengge; Xing, Mingxun; Deng, Xuming; Yu, Lu

2011-01-01

Background The targeting of Staphylococcus aureus biofilm structures are now gaining interest as an alternative strategy for developing new types of antimicrobial agents. Magnolol (MOL) shows inhibitory activity against S. aureus biofilms and Triton X-100-induced autolysis in vitro, although there are no data regarding the molecular mechanisms of MOL action in bacteria. Methodology/Principal Findings The molecular basis of the markedly reduced autolytic phenotype and biofilm inhibition triggered by MOL were explored using transcriptomic analysis, and the transcription of important genes were verified by real-time RT-PCR. The inhibition of autolysis by MOL was evaluated using quantitative bacteriolytic assays and zymographic analysis, and antibiofilm activity assays and confocal laser scanning microscopy were used to elucidate the inhibition of biofilm formation caused by MOL in 20 clinical isolates or standard strains. The reduction in cidA, atl, sle1, and lytN transcript levels following MOL treatment was consistent with the induced expression of their autolytic repressors lrgA, lrgB, arlR, and sarA. MOL generally inhibited or reversed the expression of most of the genes involved in biofilm production. The growth of S. aureus strain ATCC 25923 in the presence of MOL dose-dependently led to decreases in Triton X-100-induced autolysis, extracellular murein hydrolase activity, and the amount of extracellular DNA (eDNA). MOL may impede biofilm formation by reducing the expression of cidA, a murein hydrolase regulator, to inhibit autolysis and eDNA release, or MOL may directly repress biofilm formation. Conclusions/Significance MOL shows in vitro antimicrobial activity against clinical and standard S. aureus strains grown in planktonic and biofilm cultures, suggesting that the structure of MOL may potentially be used as a basis for the development of drugs targeting biofilms. PMID:22046374

Development of a Singlet Oxygen Absorption Capacity (SOAC) Assay Method. Measurements of the SOAC Values for Carotenoids and α-Tocopherol in an Aqueous Triton X-100 Micellar Solution.

PubMed

Mukai, Kazuo; Ouchi, Aya; Azuma, Nagao; Takahashi, Shingo; Aizawa, Koichi; Nagaoka, Shin-Ichi

2017-02-01

Recently, a new assay method for the quantification of the singlet oxygen absorption capacity (SOAC) of antioxidants (AOs) and food extracts in homogeneous organic solvents was proposed. In this study, second-order rate constants (k Q ) for the reaction of singlet oxygen ( 1 O 2 ) with eight different carotenoids (Cars) and α-tocopherol (α-Toc) were measured in an aqueous Triton X-100 (5.0 wt %) micellar solution (pH 7.4, 35 °C), which was used as a simple model of biomembranes. The k Q and relative SOAC values were measured using ultraviolet-visible (UV-vis) spectroscopy. The UV-vis absorption spectra of Cars and α-Toc were measured in both a micellar solution and chloroform, to investigate the effect of solvent on the k Q and SOAC values. Furthermore, decay rates (k d ) of 1 O 2 were measured in 0.0, 1.0, 3.0, and 5.0 wt % micellar solutions (pH 7.4), using time-resolved near-infrared fluorescence spectroscopy, to determine the absolute k Q values of the AOs. The results obtained demonstrate that the k Q values of AOs in homogeneous and heterogeneous solutions vary notably depending on (i) the polarity [dielectric constant (ε)] of the reaction field between AOs and 1 O 2 , (ii) the local concentration of AOs, and (iii) the mobility of AOs in solution. In addition, the k Q and relative SOAC values obtained for the Cars in a heterogeneous micellar solution differ remarkably from those in homogeneous organic solvents. Measurements of k Q and SOAC values in a micellar solution may be useful for evaluating the 1 O 2 quenching activity of AOs in biological systems.

Regulation of the plasma membrane type III phosphatidylinositol 4-kinase by positively charged compounds.

PubMed

Yang, W; Boss, W F

1994-08-15

The effects of positively charged compounds on a plasma membrane, type III phosphatidylinositol 4-kinase were studied. To determine whether the enzyme would respond differently to the compounds in a membrane-associated versus a soluble state, both the plasma membrane and solubilized (released by 0.01% (v/v) Triton X-100) PI 4-kinase were used. Spermidine, spermine, polylysine, cardiotoxin, melittin, and histone stimulated the solubilized PI 4-kinase but had little effect on or weakly stimulated the membrane-associated PI 4-kinase. Polyarginine inhibited membrane-associated PI 4-kinase 75% and inhibited the solubilized PI 4-kinase 30%, indicating that charge alone was not sufficient for activation. Polyarginine also eliminated the activation of the solubilized PI 4-kinase by a PI 4-kinase activator protein, PIK-A49. Calmodulin, a common calcium-binding protein, at micromolar levels strongly inhibited solubilized PI 4-kinase activity but did not inhibit membrane-associated PI 4-kinase activity. The inhibition of the solubilized PI 4-kinase by calmodulin was calcium independent. Calcium alone (1 microM-0.1 mM) inhibited PI 4-kinase activity only slightly (< 30%). The differential effects of the positively charged compounds on the solubilized and membrane-associated PI 4-kinase were not due to substrate availability because both enzymes were assayed in the presence of excess PI (0.6 mM) and 0.3% (v/v) Triton X-100. The data suggest that positively charged compounds affected the enzyme activity not only by interacting with the substrates or products of the reaction but also by interacting with the PI 4-kinase or regulatory components in the plasma membrane.

Single-use technology for solvent/detergent virus inactivation of industrial plasma products.

PubMed

Hsieh, Yao-Ting; Mullin, Lori; Greenhalgh, Patricia; Cunningham, Michael; Goodrich, Elizabeth; Shea, Jessica; Youssef, Eric; Burnouf, Thierry

2016-06-01

Virus inactivation of plasma products is conducted using stainless-steel vessels. Single-use technology can offer significant benefits over stainless such as operational flexibility, reduced capital infrastructure costs, and increased efficiency by minimizing the time and validation requirements associated with hardware cleaning. This study qualifies a single-use bag system for solvent/detergent (S/D) virus inactivation. Human plasma and immunoglobulin test materials were S/D-treated in Mobius single-use bags using 1% tri-n-butyl phosphate (TnBP) with 1% Triton X-100 or 1% Tween 80 at 31°C for 4 to 6 hours to evaluate the impact on protein quality. Volatile and nonvolatile organic leachables from low-density polyethylene film (Pureflex film) used in 1-L-scale studies after exposure to S/D in phosphate-buffered saline were identified compared to controls in glass containers. Virus inactivation studies were performed with xenotropic murine leukemia virus (XMuLV) and bovine viral diarrhea virus (BVDV) to determine the kinetics of virus inactivation, measured using infectivity assays. S/D treatment in Mobius bags did not impact the protein content and profile of plasma and immunoglobulin, including proteolytic enzymes and thrombin generation. Cumulative leachable levels after exposure to S/D were 1.5 and 1.85 ppm when using 0.3% TnBP combined with 1% Tween 80 or 1% Triton X-100, respectively. Efficient inactivation of both XMuLV and BVDV was observed, with differences in the rate of inactivation dependent on both virus and S/D mixture. Effective S/D virus inactivation in single-use container technology is achievable. It does not alter plasma proteins and induces minimal release of leachables. © 2016 The Authors. Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

Purification and characterization of an amidohydrolase for N4-long-chain fatty acyl derivatives of 1-beta-D-arabinofuranosylcytosine from mouse liver microsomes.

PubMed

Hori, K; Tsuruo, T; Tsukagoshi, S; Sakurai, Y

1984-03-01

N4-Long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase, a metabolizing enzyme for N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with long-chain fatty acids, was purified from mouse liver microsomes. The purification was accomplished by solubilization of liver microsomes with Triton X-100, diethylaminoethyl cellulose chromatography, gel filtrations, hydroxyapatite chromatography, and concanavalin A:Sepharose chromatography. On sodium dodecyl sulfate:polyacrylamide gel electrophoresis, the purified enzyme preparation produced a single protein band with a molecular weight of 54,000. The enzyme had an optimal pH of 9.0, and the Michaelis constant for N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was 67 microM. The thiols such as dithiothreitol or 2-mercaptoethanol stabilized the enzyme and stimulated its activity. p-Chloromercuribenzoate, N-ethylmaleimide, diisopropylfluorophosphate, and phenylmethylsulfonyl fluoride strongly inhibited the reaction. Bovine serum albumin markedly stimulated the enzyme activity, whereas detergents such as Triton X-100, deoxycholate, and sodium dodecyl sulfate had little effect. The enzyme did not require monovalent or divalent cations. Among the series of N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with different chain lengths of acyl residues, the purified enzyme preferentially hydrolyzed the derivatives with long-chain fatty acids (C12 to C18), and N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was the most susceptible. The purified enzyme was inactive on various N-acylamino acids, amides, oligopeptides, proteins, N-acylsphingosines (ceramides), triglyceride, lecithin, and lysolecithin. These results suggest that N4-long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase may be a new type of linear amidase.

A Sensitive Microplate Assay for Lipase Activity Measurement Using Olive Oil Emulsion Substrate: Modification of the Copper Soap Colorimetric Method.

PubMed

Mustafa, Ahmad; Karmali, Amin; Abdelmoez, Wael

2016-01-01

The present work involves a sensitive high-throughput microtiter plate based colorimetric assay for estimating lipase activity using cupric acetate pyridine reagent (CAPR). In the first approach, three factors two levels factorial design methodology was used to evaluate the interactive effect of different parameters on the sensitivity of the assay method. The optimization study revealed that the optimum CAPR concentration was 7.5% w/v, the optimum solvent was heptane and the optimum CAPR pH was 6. In the second approach, the optimized colorimetric microplate assay was used to measure lipase activity based on enzymatic hydrolysis of olive oil emulsion substrate at 37°C and 150 rpm. The emulsion substrates were formulated by using olive oil, triton X-100 (10% v/v in pH 8) and sodium phosphate buffer of pH 8 in ratio of 1:1:1 in the case of Candida sp. lipase. While in the case of immobilized lipozyme RMIM, The emulsion substrates were formulated by using olive oil, triton X-100 (1% v/v in pH 8) and sodium phosphate buffer of pH 8 in ratio of 2:1:1. Absorbance was measured at 655 nm. The stability of this assay (in terms of colored heptane phase absorbance readings) retained more than 92.5% after 24 h at 4°C compared to the absorbance readings measured at zero time. In comparison with other lipase assay methods, beside the developed sensitivity, the reproducibility and the lower limit of detection (LOD) of the proposed method, it permits analyzing of 96 samples at one time in a 96-well microplate. Furthermore, it consumes small quantities of chemicals and unit operations.

Synergistic Cardioprotective Effects of Combined Chromium Picolinate and Atorvastatin Treatment in Triton X-100-Induced Hyperlipidemia in Rats: Impact on Some Biochemical Markers.

PubMed

Shafik, Noha M; Baalash, Amal; Ebeid, Abla M

2017-12-01

Hyperlipidemia is one of the major risk factors for atherosclerosis and ischemic heart disease. Chromium (Cr) mineral is playing a crucial role in glucose and lipid homeostasis. The aim of this study was to evaluate the protective effects of combined chromium picolinate (CrPic) and atorvastatin treatment against hyperlipidemia-induced cardiac injury. Seventy-five male albino rats were divided into five groups (15 rats each). Hyperlipidemia was induced by intraperitoneal injection of a single dose of Triton X-100 (300 mg/kg body weight (b.w) (group ІІ). Treatment of hyperlipidemic rats was induced by daily administration of CrPic at a dose of 200 μg/kg b.w/day (group ІІІ), atorvastatin at a dose of 10 mg/kg/day (group IV), and combined treatment with both (group V) by gavage for 7 days. At the end of experiment, serum and heart tissues were obtained. Hyperlipidemia was confirmed by histopathology of heart tissues, marked serum dyslipidemia, increased atherogenic indices, and values of ischemia-modified albumin. In addition to increased values of proprotein convertase subtilisin/kexin type 9, activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase enzyme and high relative expression levels of pentraxin-3 were observed. However, paraoxonase-1 activity was markedly decreased in the hyperlipidemic group. Significant improvement in all assessed parameters was observed in the rat group treated with both CrPic and atorvastatin. It can be concluded that combined CrPic and atorvastatin treatments had synergistic cardioprotective effects against hyperlipidemia which may be through modulating atherosclerosis as well as cardiac and aortic damage and/or activation of anti-inflammatory and anti-oxidant pathways, thus reversing endothelial dysfunction.

Factors influencing palmitoyl-CoA oxidation by rat liver peroxisomal fractions. Substrate concentration, organelle integrity and ATP.

PubMed Central

Thomas, J; Debeer, L J; De Schepper, P J; Mannaerts, G P

1980-01-01

1. The first dehydrogenation step of peroxisomal beta-oxidation involves the reduction of O2 to H2O2. Production rates of H2O2 and acetyl units by purified rat liver peroxisomes oxidizing palmitoyl-CoA were equal, indicating that H2O2 production is a reliable index for the release of acetyl units during peroxisomal fatty-acid oxidation. 2. Measurements of H2O2 and acid-soluble oxidation products during [1-14C]palmitoyl-CoA oxidation by purified peroxisomes revealed that the number of acetyl units released per molecule of palmitoyl-CoA oxidized rapidly decreased with increasing unbound palmitoyl-CoA concentrations. Structural damage to the peroxisomes caused by detergents or other treatments also decreased the number of acetyl units released. Under conditions where oxidation proceeded linearly with time the theoretical maximum of 5 acetyl units released per molecule of palmitoyl-CoA oxidized [Lazarow (1978) J. Biol. Chem. 253, 1522--1528] was never reached. 3. Expressed in terms of acetyl units produced and measured at low unbound-palmitoyl-CoA concentrations, mitochondrial oxidation was 10--20-fold higher than peroxisomal oxidation. 4. ATP stimulated peroxisomal palmitoyl-CoA oxidation approx. 2-fold. The ATP effect required the presence of Mg2+ and was lost when peroxisomal membranes were disrupted by Triton X-100 or high concentrations of unbound palmitoyl-CoA. 5. Disruption of peroxisomes by detergents, freeze--thawing, osmotic or mechanical treatment did not stimulate palmitoyl-CoA oxidation in the presence of ATP, indicating that peroxisomal fatty-acid-CoA oxidation was not latent. In the absence of ATP, Triton X-100 stimulated peroxisomal palmitoyl-CoA oxidation approx. 2-fold. PMID:7470063

Efficiency of surfactant-enhanced bioremediation of aged polycyclic aromatic hydrocarbon-contaminated soil: Link with bioavailability and the dynamics of the bacterial community.

PubMed

Cecotti, Martina; Coppotelli, Bibiana M; Mora, Verónica C; Viera, Marisa; Morelli, Irma S

2018-09-01

Shifts in the bacterial-community dynamics, bioavailability, and biodegradation of polycyclic aromatic hydrocarbons (PAHs) of chronically contaminated soil were analyzed in Triton X-100-treated microcosms at the critical micelle concentration (T-CMC) and at two sub-CMC doses. Only the sub-CMC-dose microcosms reached sorbed-PAH concentrations significantly lower than the control: 166±32 and 135±4mgkg -1 dry soil versus 266±51mgkg -1 ; consequently an increase in high- and low-molecular-weight PAHs biodegradation was observed. After 63days of incubation pyrosequencing data evidenced differences in diversity and composition between the surfactant-modified microcosms and the control, with those with sub-CMC doses containing a predominance of the orders Sphingomonadales, Acidobacteriales, and Gemmatimonadales (groups of known PAHs-degrading capability). The T-CMC microcosm exhibited a lower richness and diversity index with a marked predominance of the order Xanthomonadales, mainly represented by the Stenotrophomonas genus, a PAHs- and Triton X-100-degrading bacterium. In the T-CMC microcosm, whereas the initial surface tension was 35mNm -1 , after 63days of incubation an increase up to 40mNm -1 was registered. The previous observation and the gas-chromatography data indicated that the surfactant may have been degraded at the CMC by a highly selective bacterial community with a consequent negative impact on PAHs biodegradation. This work obtained strong evidence for the involvement of physicochemical and biologic influences determining the different behaviors of the studied microcosms. The results reported here contribute significantly to an optimization of, surfactant-enhanced bioremediation strategies for chronically contaminated soil since the application of doses below the CMC would reduce the overall costs. Copyright © 2018 Elsevier B.V. All rights reserved.

Characterization of structural proteins of hirame rhabdovirus, HRV

USGS Publications Warehouse

Nishizawa, Toyohiko; Yoshimizu, Mamoru; Winton, James; Ahne, Winfried; Kimura, Takahisa

1991-01-01

Structural proteins of hirame rhabdovirus (HRV) were analyzed by SDS-polyacrylarnide gel electrophoresis, western blotting, 2-dimensional gel electrophoresis, and Triton X-100 treatment. Purified HRV virions were composed of: polymerase (L), glycoprotein (G), nucleoprotein (N), and 2 matrix proteins (M1 and M2). Based upon their relative mobilities, the estimated molecular weights of the proteins were: L, 156 KDa; G, 68 KDa; N, 46.4 KDa; M1, 26.4 KDa; and M2, 19.9 KDa. The electrophorehc pattern formed by the structural proteins of HRV was clearly different from that formed by pike fry rhabdovirus, spring viremia of carp virus, eel virus of America, and eel virus European X which belong to the Vesiculovirus genus; however, it resembled the pattern formed by structural proteins of viral hemorrhagic septicemia virus (VHSV) and infectious hematopoietic necrosis virus (IHNV) which are members of the Lyssavirus genus. Among HRV, IHNV, and VHSV, differences were observed in the relative mobilities of the G, N, M1, and M2 proteins. Western blot analysis revealed that the G. N, and M2 proteins of HRV shared antigenic determinants with IHNV and VHSV, but not with any of the 4 fish vesiculoviruses tested. Cross-reactions between the M1 proteins of HRV, IHNV, or VHSV were not detected in this assay. Two-dimensional gel electrophoresis was used to show that HRV differed from IHNV or VHSV in the isoelectric point (PI) of the M1 and M2 proteins. In this system, 2 forms of the M1 protein of HRV and IHNV were observed.These subspecies of M1 had the same relative mobility but different p1 values. Treatment of purified virions with 2% Triton X-100 in Tris buffer containing NaCl removed the G, M1, and M2 proteins of IHNV, but HRV virions were more stable under these conditions.

Lipid rafts are essential for peroxisome biogenesis in HepG2 cells.

PubMed

Woudenberg, Jannes; Rembacz, Krzysztof P; Hoekstra, Mark; Pellicoro, Antonella; van den Heuvel, Fiona A J; Heegsma, Janette; van Ijzendoorn, Sven C D; Holzinger, Andreas; Imanaka, Tsuneo; Moshage, Han; Faber, Klaas Nico

2010-08-01

Peroxisomes are particularly abundant in the liver and are involved in bile salt synthesis and fatty acid metabolism. Peroxisomal membrane proteins (PMPs) are required for peroxisome biogenesis [e.g., the interacting peroxisomal biogenesis factors Pex13p and Pex14p] and its metabolic function [e.g., the adenosine triphosphate-binding cassette transporters adrenoleukodystrophy protein (ALDP) and PMP70]. Impaired function of PMPs is the underlying cause of Zellweger syndrome and X-linked adrenoleukodystrophy. Here we studied for the first time the putative association of PMPs with cholesterol-enriched lipid rafts and their function in peroxisome biogenesis. Lipid rafts were isolated from Triton X-100-lysed or Lubrol WX-lysed HepG2 cells and analyzed for the presence of various PMPs by western blotting. Lovastatin and methyl-beta-cyclodextrin were used to deplete cholesterol and disrupt lipid rafts in HepG2 cells, and this was followed by immunofluorescence microscopy to determine the subcellular location of catalase and PMPs. Cycloheximide was used to inhibit protein synthesis. Green fluorescent protein-tagged fragments of PMP70 and ALDP were analyzed for their lipid raft association. PMP70 and Pex14p were associated with Triton X-100-resistant rafts, ALDP was associated with Lubrol WX-resistant rafts, and Pex13p was not lipid raft-associated in HepG2 cells. The minimal peroxisomal targeting signals in ALDP and PMP70 were not sufficient for lipid raft association. Cholesterol depletion led to dissociation of PMPs from lipid rafts and impaired sorting of newly synthesized catalase and ALDP but not Pex14p and PMP70. Repletion of cholesterol to these cells efficiently reestablished the peroxisomal sorting of catalase but not ALDP. Human PMPs are differentially associated with lipid rafts independently of the protein homology and/or their functional interaction. Cholesterol is required for peroxisomal lipid raft assembly and peroxisome biogenesis.

Hupresin Retains Binding Capacity for Butyrylcholinesterase and Acetylcholinesterase after Sanitation with Sodium Hydroxide.

PubMed

Onder, Seda; David, Emilie; Tacal, Ozden; Schopfer, Lawrence M; Lockridge, Oksana

2017-01-01

Hupresin is a new affinity resin that binds butyrylcholinesterase (BChE) in human plasma and acetylcholinesterase (AChE) solubilized from red blood cells (RBC). Hupresin is available from the CHEMFORASE company. BChE in human plasma binds to Hupresin and is released with 0.1 M trimethylammonium bromide (TMA) with full activity and 10-15% purity. BChE immunopurified from plasma by binding to immobilized monoclonal beads has fewer contaminating proteins than the one-step Hupresin-purified BChE. However, when affinity chromatography on Hupresin follows ion exchange chromatography at pH 4.5, BChE is 99% pure. The membrane bound AChE, solubilized from human RBC with 0.6% Triton X-100, binds to Hupresin and remains bound during washing with sodium chloride. Human AChE is not released in significant quantities with non-denaturing solvents, but is recovered in 1% trifluoroacetic acid. The denatured, partially purified AChE is useful for detecting exposure to nerve agents by mass spectrometry. Our goal was to determine whether Hupresin retains binding capacity for BChE and AChE after Hupresin is washed with 0.1 M NaOH. A 2 mL column of Hupresin equilibrated in 20 mM TrisCl pH 7.5 was used in seven consecutive trials to measure binding and recovery of BChE from 100 mL human plasma. Between each trial the Hupresin was washed with 10 column volumes of 0.1 M sodium hydroxide. A similar trial was conducted with red blood cell AChE in 0.6% Triton X-100. It was found that the binding capacity for BChE and AChE was unaffected by washing Hupresin with 0.1 M sodium hydroxide. Hupresin could be washed with sodium hydroxide at least seven times without losing binding capacity.

Dielectric relaxations on erythrocyte membrane as revealed by spectrin denaturation.

PubMed

Ivanov, I T; Paarvanova, B

2016-08-01

We studied the effect of spectrin denaturation at 49.5°C (TA) on the dielectric relaxations and related changes in the complex impedance, Z*, complex capacitance, C*, and dielectric loss curve of suspensions containing human erythrocytes, erythrocyte ghost membranes (EMs) and Triton-X-100 residues of EMs. The loss curve prior to, minus the loss curve after TA, resulted in a bell-shaped peak at 1.5MHz. The changes in the real and imaginary components of Z* and C* at TA, i.e., ΔZre, ΔZim, ΔCre and ΔCim, calculated in the same way, strongly varied with frequency. Between 1.0 and 12MHz the -ΔZim vs ΔZre, and ΔCim vs ΔCre plots depicted semicircles with critical frequencies, fcr, at 2.5MHz expressing recently reported relaxation of spectrin dipoles. Between 0.02 and 1.0MHz the -ΔZim vs ΔZre plot exhibited another relaxation whose fcr mirrored that of beta relaxation. This relaxation was absent on Triton-X-shells, while on erythrocytes and EMs it was inhibited by selective dissociation of either attachment sites between spectrin and bilayer. Considering above findings and inaccessibility of cytosole to outside field at such frequencies, the latter relaxation was assumed originating from a piezoelectric effect on the highly deformable spectrin filaments. Copyright © 2016 Elsevier B.V. All rights reserved.

High-level heterologous expression and properties of a novel lipase from Ralstonia sp. M1.

PubMed

Quyen, Dinh Thi; Giang Le, Thi Thu; Nguyen, Thi Thao; Oh, Tae-Kwang; Lee, Jung-Kee

2005-01-01

The mature lipase LipA and its 56aa-truncated chaperone DeltaLipBhis (with 6xhis-tag) from Ralstonia sp. M1 were over-expressed in Escherichia coli BL21 under the control of T7 promoter with a high level of 70 and 12mg protein per gram of wet cells, respectively. The simply purified lipase LipA was effectively refolded by Ni-NTA purified chaperone DeltaLipBhis in molar ratio 1:1 at 4 degrees C for 24 hours in H2O. The in vitro refolded lipase LipA had an optimal activity in the temperature range of 50-55 degrees C and was stable up to 45 degrees C with more than 84% activity retention. The maximal activity was observed at pH 10.75 for hydrolysis of olive oil and found to be stable over alkaline pH range 8.0-10.5 with more than 52% activity retention. The enzyme was found to be highly resistant to many organic solvents especially induced by ethanolamine (remaining activity 137-334%), but inhibited by 1-butanol and acetonitrile (40-86%). Metal ions Cu2+, Sn2+, Mn2+, Mg2+, and Ca2+ stimulated the lipase slightly with increase in activity by up to 22%, whereas Zn2+ significantly inhibited the enzyme with the residual activity of 30-65% and Fe3+ to a lesser degree (activity retention of 77-86%). Tween 80, Tween 60, and Tween 40 induced the activation of the lipase LipA (222-330%) and 0.2-1% (w/v) of Triton X-100, X-45, and SDS increased the lipase activity by up to 52%. However, 5% (w/v) of Triton X-100, X-45, and SDS inhibited strongly the activity by 31-89%. The inhibitors including DEPC, EDTA, PMSF, and 2-mercaptoethanol (0.1-10mM) inhibited moderately the lipase with remaining activity of 57-105%. The lipase LipA hydrolyzed a wide range of triglycerides, but preferentially short length acyl chains (C4 and C6). In contrast to the triglycerides, medium length acyl chains (C8 and C14) of p-nitrophenyl (p-NP) esters were preferential substrates of this lipase. The enzyme preferentially catalyzed the hydrolysis of cottonseed oil (317%), cornoil (227%), palm oil (222%), and wheatgerm oil (210%) in comparison to olive oil (100%).

Characterization of an apically derived epithelial membrane glycoprotein from bovine milk, which is expressed in capillary endothelia in diverse tissues.

PubMed

Greenwalt, D E; Mather, I H

1985-02-01

A glycoprotein (PAS IV) of apparent Mr 76,000 was purified from bovine milk-fat-globule membrane and partially characterized. PAS IV contained mannose, galactose, and sialic acid as principal sugars (approximately 5.3% total carbohydrate [wt/wt]) and existed in milk in at least four isoelectric variants. The glycoprotein appeared to be an integral membrane protein by several criteria. PAS IV was recovered in the detergent phase of Triton X-114 extracts of milk-fat-globule membrane at room temperature. When bound to membrane, PAS IV was resistant to digestion by a number of proteinases, although after solubilization with non-ionic detergents, the protein was readily degraded. Amino acid analysis of the purified protein revealed a high percentage of amino acids with nonpolar residues. The location of PAS IV was determined in bovine tissues by using immunofluorescence techniques. In mammary tissue, PAS IV was located on both the apical surfaces of secretory epithelial cells and endothelial cells of capillaries. This glycoprotein was also detected in endothelial cells of heart, liver, spleen, pancreas, salivary gland, and small intestine. In addition to mammary epithelial cells, PAS IV was also located in certain other epithelial cells, most notably the bronchiolar epithelial cells of lung. The potential usefulness of this protein as a specific marker of capillary endothelial cells in certain tissues is discussed.

Application of dual-cloud point extraction for the trace levels of copper in serum of different viral hepatitis patients by flame atomic absorption spectrometry: A multivariate study

NASA Astrophysics Data System (ADS)

Arain, Salma Aslam; Kazi, Tasneem G.; Afridi, Hassan Imran; Abbasi, Abdul Rasool; Panhwar, Abdul Haleem; Naeemullah; Shanker, Bhawani; Arain, Mohammad Balal

2014-12-01

An efficient, innovative preconcentration method, dual-cloud point extraction (d-CPE) has been developed for the extraction and preconcentration of copper (Cu2+) in serum samples of different viral hepatitis patients prior to couple with flame atomic absorption spectrometry (FAAS). The d-CPE procedure was based on forming complexes of elemental ions with complexing reagent 1-(2-pyridylazo)-2-naphthol (PAN), and subsequent entrapping the complexes in nonionic surfactant (Triton X-114). Then the surfactant rich phase containing the metal complexes was treated with aqueous nitric acid solution, and metal ions were back extracted into the aqueous phase, as second cloud point extraction stage, and finally determined by flame atomic absorption spectrometry using conventional nebulization. The multivariate strategy was applied to estimate the optimum values of experimental variables for the recovery of Cu2+ using d-CPE. In optimum experimental conditions, the limit of detection and the enrichment factor were 0.046 μg L-1 and 78, respectively. The validity and accuracy of proposed method were checked by analysis of Cu2+ in certified sample of serum (CRM) by d-CPE and conventional CPE procedure on same CRM. The proposed method was successfully applied to the determination of Cu2+ in serum samples of different viral hepatitis patients and healthy controls.

Ultrasound-aided high-resolution biophotonic imaging

NASA Astrophysics Data System (ADS)

Wang, Lihong V.

2003-10-01

We develop novel biophotonic imaging for early-cancer detection, a grand challenge in cancer research, using nonionizing electromagnetic and ultrasonic waves. Unlike ionizing x-ray radiation, nonionizing electromagnetic waves such as optical waves are safe for biomedical applications and reveal new contrast mechanisms and functional information. For example, our spectroscopic oblique-incidence reflectometry can detect skin cancers based on functional hemoglobin parameters and cell nuclear size with 95% accuracy. Unfortunately, electromagnetic waves in the nonionizing spectral region do not penetrate biological tissue in straight paths as do x-rays. Consequently, high-resolution tomography based on nonionizing electromagnetic waves alone, as demonstrated by our Mueller optical coherence tomography, is limited to superficial tissue imaging. Ultrasonic imaging, on the contrary, furnishes good imaging resolution but has poor contrast in early-stage tumors and has strong speckle artifacts as well. We developed ultrasound-mediated imaging modalities by combining electromagnetic and ultrasonic waves synergistically. The hybrid modalities yield speckle-free electromagnetic-contrast at ultrasonic resolution in relatively large biological tissue. In ultrasound-modulated (acousto)-optical tomography, a focused ultrasonic wave encodes diffuse laser light in scattering biological tissue. In photo-acoustic (thermo-acoustic) tomography, a low-energy laser (RF) pulse induces ultrasonic waves in biological tissue due to thermoelastic expansion.

ATP utilization for calcium uptake and force production in skinned muscle fibres of Xenopus laevis.

PubMed Central

Stienen, G J; Zaremba, R; Elzinga, G

1995-01-01

1. A method has been developed to discriminate between the rate of ATP hydrolysis associated with calcium uptake into the sarcoplasmic reticulum (SR) and force development of the contractile apparatus in mechanically or saponin-skinned skeletal muscle fibres. The rate of ATP hydrolysis was determined in fibres of different types from the iliofibularis muscle of Xenopus laevis by enzymatic coupling of ATP re-synthesis to the oxidation of NADH. 2. The ATPase activity was determined before and after exposure of the preparations for 30 min to a solution containing 0.5% Triton X-100, which effectively abolishes the SR ATPase activity. The fibres were activated in a solution containing 5 mM caffeine to ensure that calcium uptake into the SR was maximal. 3. At saturating Ca2+ concentrations the actomyosin (AM) and SR ATPase activities in fast-twitch fibres, at 4.3 degrees C, amounted to 1.52 +/- 0.07 and 0.58 +/- 0.10 mumol s-1 (g dry wt)-1, respectively (means +/- S.E.M.; n = 25). The SR ATPase activity was 25% of the total ATPase activity. At submaximal calcium concentrations the AM ATPase activity varied in proportion to the isometric force. 4. The calcium sensitivity of the SR ATPase was larger than that of the AM ATPase and its dependence on [Ca2+] was less steep. The AM ATPase activity was half-maximal at a pCa of 6.11 (pCa = -log [Ca2+]) whereas the SR ATPase activity was half-maximal at a pCa of 6.62. 5. In Triton X-100-treated fibres, at different 2,3-butanedione monoxime (BDM) concentrations, the AM ATPase activity and isometric force varied proportionally. The SR ATPase activity determined by extrapolation of the total ATPase activity in mechanically skinned or saponin-treated fibres to zero force, was independent of the BDM concentration in the range studied (0-20 mM). The values obtained for the SR ATPase activity in this way were similar to those obtained with Triton X-100 treatment. 6. The AM ATPase activity in slow-twitch fibres amounted to 0.74 +/- 0.13 mumol s-1 (g dry wt)-1, i.e. about a factor of two smaller than in fast-twitch fibres. The SR ATPase activity amounted to 0.47 +/- 0.07 mumol s-1 (g dry wt)-1, i.e. rather similar to the value in fast-twitch fibres. The proportion of the total ATPase activity that was due to SR ATPase (40%) was larger than in fast-twitch fibres. 7. The temperature dependence of the AM and SR ATPase activities in fast-twitch fibres differed. In the temperature range 5-10 degrees C, the relative changes in AM and SR ATPase activities for a 10 degrees C temperature change (Q10) were 3.9 +/- 0.3 and 7.2 +/- 1.5, respectively.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7730976

Stabilizers influence drug–polymer interactions and physicochemical properties of disulfiram-loaded poly-lactide-co-glycolide nanoparticles

PubMed Central

Hoda, Muddasarul; Sufi, Shamim Akhtar; Cavuturu, Bindumadhuri; Rajagopalan, Rukkumani

2018-01-01

Aim: Stabilizers are known to be an integral component of polymeric nanostructures. Ideally, they manipulate physicochemical properties of nanoparticles. Based on this hypothesis, we demonstrated that disulfiram (drug) and Poly-lactide-co-glycolide (polymer) interactions and physicochemical properties of their nanoparticles formulations are significantly influenced by the choice of stabilizers. Methodology: Electron microscopy, differential scanning calorimetry, x-ray diffraction, Raman spectrum analysis, isothermal titration calorimetry and in silico docking studies were performed. Results & discussion: Polysorbate 80 imparted highest crystallinity while Triton-X 100 imparted highest rigidity, possibly influencing drug bioavailability, blood-retention time, cellular uptake and sustained drug release. All the molecular interactions were hydrophobic in nature and entropy driven. Therefore, polymeric nanoparticles may be critically manipulated to streamline the passive targeting of drug-loaded nanoparticles. PMID:29379637

Slowing down of alpha particles in ICF DT plasmas

NASA Astrophysics Data System (ADS)

He, Bin; Wang, Zhi-Gang; Wang, Jian-Guo

2018-01-01

With the effects of the projectile recoil and plasma polarization considered, the slowing down of 3.54 MeV alpha particles is studied in inertial confinement fusion DT plasmas within the plasma density range from 1024 to 1026 cm-3 and the temperature range from 100 eV to 200 keV. It includes the rate of the energy change and range of the projectile, and the partition fraction of its energy deposition to the deuteron and triton. The comparison with other models is made and the reason for their difference is explored. It is found that the plasmas will not be heated by the alpha particle in its slowing down the process once the projectile energy becomes close to or less than the temperature of the electron or the deuteron and triton in the plasmas. This leads to less energy deposition to the deuteron and triton than that if the recoil of the projectile is neglected when the temperature is close to or higher than 100 keV. Our model is found to be able to provide relevant, reliable data in the large range of the density and temperature mentioned above, even if the density is around 1026 cm-3 while the deuteron and triton temperature is below 500 eV. Meanwhile, the two important models [Phys. Rev. 126, 1 (1962) and Phys. Rev. E 86, 016406 (2012)] are found not to work in this case. Some unreliable data are found in the last model, which include the range of alpha particles and the electron-ion energy partition fraction when the electron is much hotter than the deuteron and triton in the plasmas.

Treatment of hypercholesterolemia: screening of Solanum macrocarpon Linn (Solanaceae) as a medicinal plant in Benin

PubMed Central

Dougnon, Tamègnon Victorien; Bankolé, Honoré Sourou; Klotoé, Jean Robert; Sènou, Maximin; Fah, Lauris; Koudokpon, Hornel; Akpovi, Casimir; Dougnon, Tossou Jacques; Addo, Phyllis; Loko, Frédéric; Boko, Michel

2014-01-01

Objective: Hypercholesterolemia is the greatest risk factor for cardiovascular diseases. The present study is conducted to evaluate the lipid lowering activity of leaves and fruits of Solanum macrocarpon, a vegetable, on Wistar rats experimentally rendered hypercholesterolemic by Triton X-100. Materials and Methods: The leaves and fruits were administered (p.o.) for 7 days to rats at doses of 400 and 800 mg/kg of body weight. Atorvastatin was used as reference treatment drug. The data were analyzed by the Brown-Forsythe ANOVA, Dunnett’s T3 multiple comparison test, and Dunnett’s t test. All tests were done at the 5% significance level. Results: Administration of S. macrocarpon (fruits as well as leaves) resulted in a statistically significant decrease in total cholesterol, LDL-cholesterol, VLDL-cholesterol, and triglycerides in the treated groups compared with the untreated hypercholesterolemic group, regardless of the administrated doses. A significant increase in HDL-cholesterol was observed in the treated groups. Hepatic disorders due to the Triton have been corrected by S. macrocarpon. Conclusions: This vegetable effectively suppresses experimental hypercholesterolemia in Wistar rats, suggesting a protective role in cardiovascular diseases. Its use by individuals at risk should be promoted. PMID:25050314

Near Infrared Imaging as a Diagnostic Tool for Detecting Enamel Demineralization: An in vivo Study

NASA Astrophysics Data System (ADS)

Lucas, Seth Adam

Background and Objectives: For decades there has been an effort to develop alternative optical methods of imaging dental decay utilizing non-ionizing radiation methods. The purpose of this in-vivo study was to demonstrate whether NIR can be used as a diagnostic tool to evaluate dental caries and to compare the sensitivity and specificity of this method with that of conventional methods, including bitewing x-rays and visual inspection. Materials and Methods: 31 test subjects (n=31) from the UCSF orthodontic clinic undergoing orthodontic treatment with planned premolar extractions were recruited. Calibrated examiners performed caries detection examinations using conventional methods: bitewing radiographs and visual inspection. These findings were compared with the results from NIR examinations: transillumination and reflectance. To confirm the results found in the two different detection methods, a gold standard was used. After teeth were extracted, polarized light microscopy and transverse microradiography were performed. Results: A total of 87 premolars were used in the study. NIR identified the occlusal lesions with a sensitivity of 71% and a specificity of 77%, whereas, the visual examination had a sensitivity of only 40% and a specifity of 39%. For interproximal lesions halfway to DEJ, specificity remained constant, but sensitivity improved to 100% for NIR and 75% for x-rays. Conclusions: The results of this preliminary study demonstrate that NIR is just as effective at detecting enamel interproximal lesions as standard dental x-rays. NIR was more effective at detecting occlusal lesions than visual examination alone. NIR shows promise as an alternative diagnostic tool to the conventional methods of x-rays and visual examination and provides a non-ionizing radiation technique.

Identification of sucrose synthase as an actin-binding protein

NASA Technical Reports Server (NTRS)

Winter, H.; Huber, J. L.; Huber, S. C.; Davies, E. (Principal Investigator)

1998-01-01

Several lines of evidence indicate that sucrose synthase (SuSy) binds both G- and F-actin: (i) presence of SuSy in the Triton X-100-insoluble fraction of microsomal membranes (i.e. crude cytoskeleton fraction); (ii) co-immunoprecipitation of actin with anti-SuSy monoclonal antibodies; (iii) association of SuSy with in situ phalloidin-stabilized F-actin filaments; and (iv) direct binding to F-actin, polymerized in vitro. Aldolase, well known to interact with F-actin, interfered with binding of SuSy, suggesting that a common or overlapping binding site may be involved. We postulate that some of the soluble SuSy in the cytosol may be associated with the actin cytoskeleton in vivo.

Molecular mass determination and assay of venom hyaluronidases by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

PubMed

Cevallos, M A; Navarro-Duque, C; Varela-Julia, M; Alagon, A C

1992-08-01

We describe a procedure for molecular mass determination of hyaluronidases present in animal venoms from different families. Hyaluronidases can be revealed, following their electrophoretic separation in sodium dodecyl sulfate-polyacrylamide gel containing hyaluronic acid, by incubating the gel in Triton X-100 to remove sodium dodecyl sulfate and restore in situ enzyme activity. This method allows the detection of as little as 0.025 turbidity-reducing units after 2 hr incubation. All the hyaluronidases from the analyzed invertebrate venoms had a mass below 50,000 and showed only one component, while those from vertebrate venoms were more than 60,000 and in many instances contained more than one form.

Acetone Powder From Dormant Seeds of Ricinus communis L

NASA Astrophysics Data System (ADS)

Cavalcanti, Elisa D. C.; Maciel, Fábio M.; Villeneuve, Pierre; Lago, Regina C. A.; Machado, Olga L. T.; Freire, Denise M. G.

The influence of several factors on the hydrolytic activity of lipase, present in the acetone powder from dormant castor seeds (Ricinus communis) was evaluated. The enzyme showed a marked specificity for short-chain substrates. The best reaction conditions were an acid medium, Triton X-100 as the emulsifying agent and a temperature of 30°C. The lipase activity of the acetone powder of different castor oil genotypes showed great variability and storage stability of up to 90%. The toxicology analysis of the acetone powder from genotype Nordestina BRS 149 showed a higher ricin (toxic component) content, a lower 2S albumin (allergenic compound) content, and similar allergenic potential compared with untreated seeds.

Inhibition of rat brain monoamine oxidase by repeated administration of pirlindol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verevkina, I.V.; Asnina, V.V.; Gorkin, V.Z.

1985-10-01

Since pirlindol, like other antidepressants, is used for a long time and since its therapeutic effect usually appears 5-7 days or more after the beginning of treatment, the authors investigate its action on activity of MAO of types A and B in rat brain when administered repeatedly. MAO activity was determined in 50% homogenates of rat brain, made up in 10 mM phosphate buffer, pH 7.4, containing 2% detergent Triton X-100. It is shown that an important role in the antidepressant effect of pirlindol is played by its property of selectively blocking deamination of neurotrans mitters such as serotonin andmore » noradrenalin in the human brain.« less

Preparation of AN Electrode Modified with a Thermostable Enzyme BACILLUS Subtilis COTA by Electrodeposition

NASA Astrophysics Data System (ADS)

Watanabe, Toshio; Yamada, Yohei; Motonaka, Junko; Yabutani, Tomoki; Sakuraba, Haruhiko; Yasuzawa, Mikito

In this study, electrodeposition of thermostable enzyme Bacillus subtilis CotA, which is a laccase and has a bilirubin oxidase (BOD) activity, was investigated. The electrodeposition was operated in a mixture of Bacillus subtilis CotA in the PBS (pH 8.0) and TritonX-100 under applying potential (1100 mV vs. Ag/AgCl for 5 min.). The current response was measured by linear sweep voltammetry technique (LSV). The thermostable enzyme Bacillus subtilis CotA electrodeposited electrode was compared with a mesophile BOD electrodeposited electrode. As a result, the Bacillus subtilis CotA modified electrode showed better sensitivity and long-term stability than the mesophile BOD modified electrode.

A novel prenyltransferase from Paracoccus denitrificans.

PubMed Central

Ishii, K; Sagami, H; Ogura, K

1986-01-01

A new polyprenyltransferase catalysing the formation of Z-double bonds was found and partially purified from extracts of Paracoccus denitrificans. The enzyme catalysed a consecutive condensation of isopentenyl diphosphate with EE-farnesyl diphosphate as a primer to produce EE-farnesyl-all-Z-hexaprenyl diphosphate (ZE-mixed nonaprenyl diphosphate) as the final product. Not only EE-farnesyl diphosphate but also neryl diphosphate, ZE-farnesyl diphosphate, ZEE-geranylgeranyl diphosphate and ZZEE-pentaprenyl diphosphate were all accepted as substrates. This polyprenyltransferase required detergent such as Triton X-100 for its catalytic activity. The formation of ZE-mixed undecaprenyl diphosphate, which is well known as the precursor of the bacterial sugar-carrier lipid, was not detected in extracts of this bacterium. PMID:3707524

Localized Surface Plasmon Resonance with Five-Branched Gold Nanostars in a Plastic Optical Fiber for Bio-Chemical Sensor Implementation

PubMed Central

Cennamo, Nunzio; D'Agostino, Girolamo; Donà, Alice; Dacarro, Giacomo; Pallavicini, Piersandro; Pesavento, Maria; Zeni, Luigi

2013-01-01

In this paper a refractive index sensor based on localized surface plasmon resonance (LSPR) in a Plastic Optical Fiber (POF), is presented and experimentally tested. LSPR is achieved exploiting five-branched gold nanostars (GNS) obtained using Triton X-100 in a seed-growth synthesis. They have the uncommon feature of three localized surface plasmon resonances. The strongest LSPRs fall in two ranges, one in the 600–900 nm range (LSPR 2) and the other one in the 1,100–1,600 nm range (LSPR 3), both sensible to refractive index changes. Anyway, due to the extremely strong attenuation (>102 dB/m) of the employed POF in the 1,100–1,600 nm range, only LSPR 2 will be exploited for refractive index change measurements, useful for bio-chemical sensing applications, as a proof of principle of the possibility of realizing a compact, low cost and easy-to-use GNS based device. PMID:24172284

Localized surface plasmon resonance with five-branched gold nanostars in a plastic optical fiber for bio-chemical sensor implementation.

PubMed

Cennamo, Nunzio; D'Agostino, Girolamo; Donà, Alice; Dacarro, Giacomo; Pallavicini, Piersandro; Pesavento, Maria; Zeni, Luigi

2013-10-29

In this paper a refractive index sensor based on localized surface plasmon resonance (LSPR) in a Plastic Optical Fiber (POF), is presented and experimentally tested. LSPR is achieved exploiting five-branched gold nanostars (GNS) obtained using Triton X-100 in a seed-growth synthesis. They have the uncommon feature of three localized surface plasmon resonances. The strongest LSPRs fall in two ranges, one in the 600-900 nm range (LSPR 2) and the other one in the 1,100-1,600 nm range (LSPR 3), both sensible to refractive index changes. Anyway, due to the extremely strong attenuation (>10(2) dB/m) of the employed POF in the 1,100-1,600 nm range, only LSPR 2 will be exploited for refractive index change measurements, useful for bio-chemical sensing applications, as a proof of principle of the possibility of realizing a compact, low cost and easy-to-use GNS based device.

Characterization of the membrane-bound succinic dehydrogenase of Micrococcus lysodeikticus.

PubMed

Pollock, J J; Linder, R; Salton, M R

1971-07-01

The occurrence of succinic dehydrogenase [succinic:(acceptor) oxidoreductase, EC 1.3.99.1] in membrane fractions of Micrococcus lysodeikticus was investigated. The enzyme could be purified 10-fold, by deoxycholate treatment. Butanol extraction of membranes yielded an active fraction, nonsedimentable at 130,000 x g for 2 hr and altered in its phospholipid content relative to membranes. The activity of the enzyme in particulate preparations was decreased in the presence of competitive inhibitors and by compounds known to react with iron, sulfhydryl groups, and flavine. In this respect, the bacterial succinic dehydrogenase is similar to the enzyme derived from yeast and mammalian sources. In certain membrane fractions, Ca(2+) and Mg(2+) exhibited inhibitory effects whereas Triton X-100 caused activation. The enzyme could also be activated by substrate. In the phenazine reductase assay, incomplete reduction of electron acceptor was observed upon addition of divalent cations and iron binding agents.

The Atmospheric Structure of Triton and Pluto

NASA Technical Reports Server (NTRS)

Elliot, James L.

1998-01-01

The goal of this research was to better determine the atmospheric structures of Triton and Pluto through further analysis of three occultation data sets obtained with the Kuiper Airborne Observatory (KAO.) As the research progressed, we concentrated our efforts on the Triton data, as this appeared to be the most fruitful. Three papers have been prepared as a result of this research. The first paper presents new results about Triton's atmospheric structure from the analysis of all ground-based stellar occultation data recorded to date, including one single-chord occultation recorded on 1993 July 10 and nine occultation lightcurves from the double-star event on 1995 August 14. These stellar occultation observations made both in the visible and in the infrared have good spatial coverage of Triton, including the first Triton central-flash observations, and are the first data to probe the altitude level 20-100 km on Triton. The small-planet lightcurve model of J. L. Elliot and L. A. Young was generalized to include stellar flux refracted by the far limb, and then fitted to the data. Values of the pressure, derived from separate immersion and emersion chords, show no significant trends with latitude, indicating that Triton's atmosphere is spherically symmetric at approximately 50 km altitude to within the error of the measurements; however, asymmetry observed in the central flash indicates the atmosphere is not homogenous at the lowest levels probed (approximately 20 km altitude). From the average of the 1995 occultation data, the equivalent isothermal temperature of the atmosphere is 47 plus or minus 1 K and the atmospheric pressure at 1400 km radius (approximately 50 km altitude) is 1.4 plus or minus 0.1 microbar. Both of these are not consistent with a model based on Voyager UVS and RSS observations in 1989. The atmospheric temperature from the occultation is 5 K colder than that predicted by the model and the observed pressure is a factor of 1.8 greater than the model. In our opinion, the disagreement in temperature and pressure is probably due to modeling problems at the microbar level, since measurements at this level have not previously been made. Alternatively, the difference could be due to seasonal change in Triton's atmospheric structure. The second paper reports observations of a recent stellar occultation by Triton which, when combined with earlier results, show that Triton has undergone a period of global warming since 1989. The most conservative estimates of the rate of temperature and surface-pressure increase during this period imply that the atmosphere is doubling in bulk every 10 years -- significantly faster than predicted by published frost model for Triton. Our results suggests that permanent polar caps on Triton play a dominant role in regulating seasonal atmospheric changes. Similar processes should also be active on Pluto. A third paper 'Global Warming on Triton' will appear in a the January 1999 issue of Sky and Telescope.

Membrane-associated mucins in normal human conjunctiva.

PubMed

Berry, M; Ellingham, R B; Corfield, A P

2000-02-01

To examine the presence of specific membrane-associated mucins in normal human conjunctiva. Glycoconjugates were extracted from membranes with two detergents: octylglucoside and Triton X114. Mucins were separated by cesium chloride density gradient centrifugation. Size was assessed by gel filtration on Sepharose CL2B and charge by ion-exchange chromatography on MonoQ. Cross reaction with antibodies against mucin gene products was assessed in blots of electrophoresis gels. Extraction of total tissue membranes yielded material with a buoyant density typical of mucins. Gel filtration showed material reacting with antimucin antibodies in a range of molecular sizes. Agarose electrophoresis confirmed the presence of MUC1 and MUC4 and the absence of MUC2 or MUC5AC. Isolation of membrane mucins by sequential, exhaustive extraction with octylglucoside followed by Triton X114 suggested the existence of mucins in different membrane environments. Reagents to carbohydrate epitopes revealed high mobility material, comigrating with MUC1 and MUC4. Low mobility membrane-bound mucins did not cross-react with any antibodies to mucin genes known to be expressed in human conjunctiva. Membrane-associated mucins are distinct from secreted mucins in normal human conjunctiva. MUC1 and MUC4 mature products decorate the membranes of conjunctival epithelial cells. Their segregation between octyl glucoside and the detergent and aqueous phases of Triton X114 suggests a variety of membrane anchoring modes.

A novel method for the determination of synthetic colors in ice cream samples.

PubMed

Tripathi, Meenakshi; Khanna, Subhash K; Das, Mukul

2004-01-01

A simple method has been developed for the extraction, separation, and determination of synthetic colors in ice cream samples. The process involves the breakdown of emulsion by neutral detergents (Triton X-100 and Tween 20) followed by extraction with petroleum ether for removal of fat. The aqueous colored solution obtained is treated with 5% acetic acid, and the uptake of color is carried out by a wool-dyeing technique. The color is eluted from the wool with 5% ammonia solution, the solution is evaporated to dryness, and the residue is dissolved in 60% ethanol for paper chromatography using trisodium citrate-ammonia-water (2 + 5 + 95, w/v/v) as the mobile phase. The colored spots from the paper chromatogram are cut and eluted with 60% ethanol, and the absorbance is measured at the respective lambda maximum corresponding to the Rf value of the appropriate standard. The recoveries of 6 colors, including sunset yellow FCF (SSYFCF), tartrazine, carmoisine, ponceau 4R, brilliant blue FCF (BBFCF), and fast green FCF from spiked samples with either detergent were found to be >90%. However, recoveries of erythrosine were 21 and 65% with Triton X-100 and Tween 20, respectively. Indigo carmine could not be recovered at all because of its fugitive property in 5% ammonia solution, which is used to strip the color from the wool. The sensitivity of the method with the use of Tween 20 is 1 ppm (1 microg/g) for the colors in spiked ice cream samples. With this method, we analyzed samples of 20 branded colored ice cream. The results showed the presence of tartrazine (8.4-43.3 ppm), SSYFCF (23.5-117.6 ppm), carmoisine (traces-53.2 ppm), erythrosine (3.5 ppm), and BBFCF (4.1 ppm) in the ice cream samples. Apart from 2 samples of tuttifruity, all of the ice cream samples showed the presence of permitted synthetic colors below the permissible level of 100 ppm established by the Prevention of Food Adulteration Act of India.

Cloud-point extraction and reversed-phase high-performance liquid chromatography for the determination of synthetic phenolic antioxidants in edible oils.

PubMed

Chen, Miao; Xia, Qinghai; Liu, Mousheng; Yang, Yaling

2011-01-01

A cloud-point extraction (CPE) method using Triton X-114 (TX-114) nonionic surfactant was developed for the extraction and preconcentration of propyl gallate (PG), tertiary butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) from edible oils. The optimum conditions of CPE were 2.5% (v/v) TX-114, 0.5% (w/v) NaCl and 40 min equilibration time at 50 °C. The surfactant-rich phase was then analyzed by reversed-phase high-performance liquid chromatography with ultraviolet detection at 280 nm, using a gradient mobile phase consisting of methanol and 1.5% (v/v) acetic acid. Under the studied conditions, 4 synthetic phenolic antioxidants (SPAs) were successfully separated within 24 min. The limits of detection (LOD) were 1.9 ng mL(-1) for PG, 11 ng mL(-1) for TBHQ, 2.3 ng mL(-1) for BHA, and 5.9 ng mL(-1) for BHT. Recoveries of the SPAs spiked into edible oil were in the range 81% to 88%. The CPE method was shown to be potentially useful for the preconcentration of the target analytes, with a preconcentration factor of 14. Moreover, the method is simple, has high sensitivity, consumes much less solvent than traditional methods, and is environment-friendly. Practical Application: The method established in this article uses less organic solvent to extract SPAs from edible oils; it is simple, highly sensitive and results in no pollution to the environment.

Application of dual-cloud point extraction for the trace levels of copper in serum of different viral hepatitis patients by flame atomic absorption spectrometry: a multivariate study.

PubMed

Arain, Salma Aslam; Kazi, Tasneem G; Afridi, Hassan Imran; Abbasi, Abdul Rasool; Panhwar, Abdul Haleem; Naeemullah; Shanker, Bhawani; Arain, Mohammad Balal

2014-12-10

An efficient, innovative preconcentration method, dual-cloud point extraction (d-CPE) has been developed for the extraction and preconcentration of copper (Cu(2+)) in serum samples of different viral hepatitis patients prior to couple with flame atomic absorption spectrometry (FAAS). The d-CPE procedure was based on forming complexes of elemental ions with complexing reagent 1-(2-pyridylazo)-2-naphthol (PAN), and subsequent entrapping the complexes in nonionic surfactant (Triton X-114). Then the surfactant rich phase containing the metal complexes was treated with aqueous nitric acid solution, and metal ions were back extracted into the aqueous phase, as second cloud point extraction stage, and finally determined by flame atomic absorption spectrometry using conventional nebulization. The multivariate strategy was applied to estimate the optimum values of experimental variables for the recovery of Cu(2+) using d-CPE. In optimum experimental conditions, the limit of detection and the enrichment factor were 0.046μgL(-1) and 78, respectively. The validity and accuracy of proposed method were checked by analysis of Cu(2+) in certified sample of serum (CRM) by d-CPE and conventional CPE procedure on same CRM. The proposed method was successfully applied to the determination of Cu(2+) in serum samples of different viral hepatitis patients and healthy controls. Copyright © 2014 Elsevier B.V. All rights reserved.

Acellular vascular matrix grafts from human placenta chorion: Impact of ECM preservation on graft characteristics, protein composition and in vivo performance.

PubMed

Schneider, Karl H; Enayati, Marjan; Grasl, Christian; Walter, Ingrid; Budinsky, Lubos; Zebic, Gabriel; Kaun, Christoph; Wagner, Anja; Kratochwill, Klaus; Redl, Heinz; Teuschl, Andreas H; Podesser, Bruno K; Bergmeister, Helga

2018-05-29

Small diameter vascular grafts from human placenta, decellularized with either Triton X-100 (Triton) or SDS and crosslinked with heparin were constructed and characterized. Graft biochemical properties, residual DNA, and protein composition were evaluated to compare the effect of the two detergents on graft matrix composition and structural alterations. Biocompatibility was tested in vitro by culturing the grafts with primary human macrophages and in vivo by subcutaneous implantation of graft conduits (n = 7 per group) into the flanks of nude rats. Subsequently, graft performance was evaluated using an aortic implantation model in Sprague Dawley rats (one month, n = 14). In situ graft imaging was performed using MRI angiography. Retrieved specimens were analyzed by electromyography, scanning electron microscopy, histology and immunohistochemistry to evaluate cell migration and the degree of functional tissue remodeling. Both decellularization methods resulted in grafts of excellent biocompatibility in vitro and in vivo, with low immunogenic potential. Proteomic data revealed removal of cytoplasmic proteins with relative enrichment of ECM proteins in decelluarized specimens of both groups. Noteworthy, LC-Mass Spectrometry analysis revealed that 16 proteins were exclusively preserved in Triton decellularized specimens in comparison to SDS-treated specimens. Aortic grafts showed high patency rates, no signs of thrombus formation, aneurysms or rupture. Conduits of both groups revealed tissue-specific cell migration indicative of functional remodeling. This study strongly suggests that decellularized allogenic grafts from the human placenta have the potential to be used as vascular replacement materials. Both detergents produced grafts with low residual immunogenicity and appropriate mechanical properties. Observed differences in graft characteristics due to preservation method had no impact on successful in vivo performance in the rodent model. Copyright © 2018 Elsevier Ltd. All rights reserved.

High-Melting Lipid Mixtures and the Origin of Detergent-Resistant Membranes Studied with Temperature-Solubilization Diagrams

PubMed Central

Sot, Jesús; Manni, Marco M.; Viguera, Ana R.; Castañeda, Verónica; Cano, Ainara; Alonso, Cristina; Gil, David; Valle, Mikel; Alonso, Alicia; Goñi, Félix M.

2014-01-01

The origin of resistance to detergent solubilization in certain membranes, or membrane components, is not clearly understood. We have studied the solubilization by Triton X-100 of binary mixtures composed of egg sphingomyelin (SM) and either ceramide, diacylglycerol, or cholesterol. Solubilization has been assayed in the 4–50°C range, and the results are summarized in a novel, to our knowledge, form of plots, that we have called temperature-solubilization diagrams. Despite using a large detergent excess (lipid/detergent 1:20 mol ratio) and extended solubilization times (24–48 h) certain mixtures were not amenable to Triton X-100 solubilization at one or more temperatures. DSC of all the lipid mixtures, and of all the lipid + detergent mixtures revealed that detergent resistance was associated with the presence of gel domains at the assay temperature. Once the system melted down, solubilization could occur. In general adding high-melting lipids limited the solubilization, whereas the addition of low-melting lipids promoted it. Lipidomic analysis of Madin-Darby canine kidney cell membranes and of the corresponding detergent-resistant fraction indicated a large enrichment of the nonsolubilized components in saturated diacylglycerol and ceramide. SM-cholesterol mixtures were special in that detergent solubilization was accompanied, for certain temperatures and compositions, by an independent phenomenon of reassembly of the partially solubilized lipid bilayers. The temperature at which lysis and reassembly prevailed was ∼25°C, thus for some SM-cholesterol mixtures solubilization occurred both above and below 25°C, but not at that temperature. These observations can be at the origin of the detergent resistance effects observed with cell membranes, and they also mean that cholesterol-containing detergent-resistant membrane remnants cannot correspond to structures existing in the native membrane before detergent addition. PMID:25517149

/sup 45/Ca distribution and transport in saponin skinned vascular smooth muscle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stout, M.A.; Diecke, F.P.

1983-04-01

/sup 45/Ca distribution and transport were studied in chemically skinned strips of caudal artery from Kyoto Wistar rats. Sarcolemmal membranes were made hyperpermeable by exposure for 60 min to solutions containing 0.1 mg/ml of saponin. Skinned helical strips responded with graded contractions to changes in ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid buffered free Ca solutions (10(-7) to 10(-5) M) and were sensitive to the Mg-ATP concentration. Tissues loaded in the presence of 10(-7) M Ca contracted in response to 10 mM caffeine. These experiments indicate the strips are skinned and possess a functional regulatory and contractile system and an intact Camore » sequestering system. /sup 45/Ca distributes in three compartments in skinned caudal artery strips. The Ca contents of two components are linear functions of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration and desaturate at rapid rates. They correspond to the extracellular and cytoplasmic spaces. A significantly smaller component releases Ca at comparatively slower rates. /sup 45/Ca uptake by the slow component consists of an ATP-dependent and an ATP-independent fraction. The /sup 45/Ca content of the ATP-dependent fraction is a function of the free Ca concentration and is independent of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration. Its content was enhanced by oxalate and was abolished by Triton X-100 skinning solutions. The ATP-independent component was not affected by Triton X-100 skinning and may represent Ca binding to cytoplasmic molecules and structures. The sequestered Ca was released with caffeine or Ca but not by epinephrine. The observations indicate that the sarcoplasmic reticulum and mitochondria of vascular smooth muscle strips skinned with saponin retain their functional integrity after saponin skinning.« less

Recovery of spiked Δ9-tetrahydrocannabinol in oral fluid from polypropylene containers.

PubMed

Molnar, Anna; Lewis, John; Fu, Shanlin

2013-04-10

Oral fluid is currently used by Australian and international law enforcement agencies and employers to detect recent use of cannabis and other drugs of abuse. The main psychoactive constituent of cannabis, Δ(9)-tetrahydrocannabinol (THC), is highly lipophilic and losses occur when in contact with plastic, possibly due to its adsorption onto the plastic surface. This study aims to investigate factors governing the interaction of THC with plastic and search for ways of overcoming such interaction so to improve THC recovery. As polypropylene is one of the most common types of plastic used in collection devices, it was the focus of this study. All experiments were done by preparing neat oral fluid samples spiked with THC in 2-mL polypropylene centrifuge tubes. Samples were transferred with or without prior addition of Triton(®) X-100 (0.25%) to glass tubes containing d3-THC as internal standard and 0.1M phosphate buffer was then added. Samples were extracted by liquid-liquid extraction using hexane/ethyl acetate (9:1, v/v), dried and analysed by gas chromatography-mass spectrometry (GC-MS) after derivatisation. No significant difference was found in terms of THC loss to plastic when the concentration ranged from 25 to 1000 ng/mL in the same volume of oral fluid. Varying the oral fluid volume (0.5-1.5 mL) while keeping THC at a constant concentration showed an upward trend with more loss associated with lower volumes. The use of Triton(®) X-100 significantly decreased the adherence of THC to the plastic tubes and increased the THC transfer (>96%) at all volumes tested. Degradation of THC during storage was also studied over a 4-week period and it was found that azide did not seem to play a significant role in preserving THC in oral fluid. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Purification and characterization of a 22-kDa microsomal protein from rat parotid gland which is phosphorylated following stimulation by agonists involving cAMP as second messenger.

PubMed

Thiel, G; Schmidt, W E; Meyer, H E; Söling, H D

1988-01-04

Stimulation of secretion in exocrine glands by agonists involving cAMP as second messenger leads to the phosphorylation of the ribosomal protein S6 (protein I) and two other particulate proteins with apparent molecular masses of 24 kDa (protein II) and 22 kDa (protein III) [Jahn, R., Unger, C. & Söling, H. D. (1980) Eur. J. Biochem. 112, 345-352]. This report describes the purification and characterization of protein III. Solubilization studies indicate that protein III is an intrinsic membrane protein. It could be extracted from the endoplasmic reticulum membrane only with Triton X-100, SDS or concentrated formic or acetic acid. The purification of this protein involved extraction of the microsomes with Triton X-100, removal of the detergent by acetone precipitation, extraction of water-soluble proteins, lipids and lipoproteins, and preparative SDS polyacrylamide gel electrophoresis. The protein has a basic pI (greater than 8.7). For determination of the amino acid composition of protein III and for sequencing of its amino-terminal portion, the protein was electroeluted out off the gel, the detergent removed and the protein finally purified by reversed-phase HPLC. Protein III could be phosphorylated in vitro by the catalytic subunit of the cAMP-dependent protein kinase to a degree of approximately 0.14 mol phosphate/mol protein. The only phosphopeptide obtained after in vitro phosphorylation and subsequent tryptic or chymotryptic digestion was identical with the phosphopeptide obtained after stimulation of intact rat parotid gland lobules with isoproterenol. The sequence of this peptide was Lys-Leu-Ser(P)-Glu-Ala-Asp-Asn-Arg. It was confirmed by an analysis of the synthetic peptide following in vitro phosphorylation with cAMP-dependent protein kinase. The first 41 N-terminal residues of protein III were sequenced. So far no sequence homology with other known peptides or proteins could be found.

The Titan haze revisted: Magnetospheric energy sorces quantitative tholin yields

NASA Technical Reports Server (NTRS)

Thompson, W. Reid; Mcdonald, Gene D.; Sagan, Carl

1994-01-01

We present laboratory measurements of the radiation yields of complex organic solids produced from N2/CH4 gas mixtures containing 10 or 0.1% CH4. These tholins are thought to resemble organic aerosols produced in the atmospheres of Titan, Pluto, and Triton. The tholin yields are large compared to the total yield of gaseous products: nominally, 13 (C + N)/100 eV for Titan tholin and 2.1 (C + N)/100 eV for Triton tholin. High-energy magnetospheric electrons responsible for tholin production represents a class distinct from the plasma electrons considered in models of Titan's aiglow. Electrons with E greater than 20 keV provide an energy flux approximately 1 x 10(exp -2) erg/cm/sec, implying from our measured tholin yields a mass flux of 0.5 to 4.0 x 10(exp -14) g/sq cm/sec of tholin. (The corresponding thickness of the tholin sedimentary column accumulated over 4 Gyr on Titan's surface is 4 to 30 m). This figure is in agreement with required mass fluxes computed from recent radiative transfer and sedimentation models. If, however, theses results, derived from experiments at approximately 2 mb, are applied to lower pressure levels toward peak auroral electron energy deposition and scaled with pressure as the gas-phase organic yields, the derived tholin mass flux is at least an order of magnitude less. We attrribute this difference to the fact that tholin synthesis occurs well below the level of maximum electron energy depositon and to possible contributions to tholis from UV-derived C2-hydrocarbons. We conclude that Tita tholin, produced by magnetospheric electrons, is alone sufficient to supply at least a significant fraction of Titan's haze-a result consistent with the fact that the optical properties of Titan tholin, among all proposed material, are best at reproducing Titan's geometric albedo spectrum from near UV to mid-IR in light-scattering models.

Dynamic nuclear polarization enhanced nuclear magnetic resonance and electron spin resonance studies of hydration and local water dynamics in micelle and vesicle assemblies.

PubMed

McCarney, Evan R; Armstrong, Brandon D; Kausik, Ravinath; Han, Songi

2008-09-16

We present a unique analysis tool for the selective detection of local water inside soft molecular assemblies (hydrophobic cores, vesicular bilayers, and micellar structures) suspended in bulk water. Through the use of dynamic nuclear polarization (DNP), the (1)H NMR signal of water is amplified, as it interacts with stable radicals that possess approximately 658 times higher spin polarization. We utilized stable nitroxide radicals covalently attached along the hydrophobic tail of stearic acid molecules that incorporate themselves into surfactant-based micelle or vesicle structures. Here, we present a study of local water content and fluid viscosity inside oleate micelles and vesicles and Triton X-100 micelles to serve as model systems for soft molecular assemblies. This approach is unique because the amplification of the NMR signal is performed in bulk solution and under ambient conditions with site-specific spin labels that only detect the water that is directly interacting with the localized spin labels. Continuous wave (cw) electron spin resonance (ESR) analysis provides rotational dynamics of the spin-labeled molecular chain segments and local polarity parameters that can be related to hydration properties, whereas we show that DNP-enhanced (1)H NMR analysis of fluid samples directly provides translational water dynamics and permeability of the local environment probed by the spin label. Our technique therefore has the potential to become a powerful analysis tool, complementary to cw ESR, to study hydration characteristics of surfactant assemblies, lipid bilayers, or protein aggregates, where water dynamics is a key parameter of their structure and function. In this study, we find that there is significant penetration of water inside the oleate micelles with a higher average local water viscosity (approximately 1.8 cP) than in bulk water, and Triton X-100 micelles and oleate vesicle bilayers mostly exclude water while allowing for considerable surfactant chain motion and measurable water permeation through the soft structure.

Characterization of a beta-glycosidase highly active on disaccharides and of a beta-galactosidase from Tenebrio molitor midgut lumen.

PubMed

Ferreira, Alexandre H P; Terra, Walter R; Ferreira, Clélia

2003-02-01

The midgut of the yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae) larvae has four beta-glycosidases. The properties of two of these enzymes (betaGly1 and betaGly2) have been described elsewhere. In this paper, the characterization of the other two glycosidases (betaGly3 and betaGly4) is described. BetaGly3 has one active site, hydrolyzes disaccharides, cellodextrins, synthetic substrates and beta-glucosides produced by plants. The enzyme is inhibited by amygdalin, cellotriose, cellotetraose and cellopentaose in high concentrations, probably due to transglycosylation. betaGly3 hydrolyzes beta 1,4-glycosidic linkages with a catalytic rate independent of the substrate polymerization degree (k(int)) of 11.9 s(-1). Its active site is formed by four subsites, where subsites +1 and -1 bind glucose residues with higher affinity than subsite +2. The main role of betaGly3 seems to be disaccharide hydrolysis. BetaGly4 is a beta-galactosidase, since it has highest activity against beta-galactosides. It can also hydrolyze fucosides, but not glucosides, and has Triton X-100 as a non-essential activator (K(a)=15 microM, pH 4.5). betaGly4 has two active sites that can hydrolyze p-nitrophenyl beta-galactoside (NPbetaGal). The one hydrolyzing NPbetaGal with more efficiency is also active against methylumbellipheryl beta-D-galactoside and lactose. The other active site hydrolyzes NPbetaFucoside and binds NPbetaGal weakly. BetaGly4 hydrolyzes hydrophobic substrates with high catalytical efficiency and is able to bind octyl-beta-thiogalactoside in its active site with high affinity. The betaGly4 physiological role is supposed to be the hydrolysis of galactolipids that are found in membranes from vegetal tissues. As the enzyme has a hydrophobic site where Triton X-100 can bind, it might be activated by membrane lipids, thus becoming fully active only at the surface of cell membranes.

Regioselective hydroxylation of isoflavones by Streptomyces avermitilis MA-4680.

PubMed

Roh, Changhyun; Seo, Su-Hyun; Choi, Kwon-Young; Cha, Minho; Pandey, Bishnu Prasad; Kim, June-Hyung; Park, Jun-Seong; Kim, Duck Hee; Chang, Ih Seop; Kim, Byung-Gee

2009-07-01

Screening of bacterial whole cells was performed for regioselective hydroxylation of daidzein and genistein. Among the strains examined, Streptomyces avermitilis MA-4680 showed high ortho-dihydroxylation activity to produce 3',4',7-trihydroxyisoflavone and 3',4',5,7-tetrahydroxyisoflavone from daidzein (4',7-dihydroxyisoflavone) and genistein (4',5,7-trihydroxyisoflavone), respectively. Using 100 mg cells (wet wt.) and 1% (v/v) Triton X100 in 1 ml of total reaction volume, where 100 microl of the substrate solution (0.5 mM in 10% (v/v) mixed solvent of DMSO:MeOH = 3:7) was added to 900 microl of potassium phosphate buffer (100 mM, pH 7.2), a 16% molar conversion yield of 3',4',7-trihydroxyisoflavone was obtained from 0.5 mM daidzein after 24 h of reaction time at 28 degrees C and 200 rpm. Ketoconazole significantly (ca. 90%) inhibited the ortho-hydroxylation activity of daidzein, suggesting that cytochrome P450 enzymes putatively play roles in regiospecific daidzein hydroxylation. The analysis of the reaction products was determined by gas chromatography/mass spectrometry (GC/MS) and (1)H NMR.

Selective removal of polycyclic aromatic hydrocarbons (PAHs) from soil washing effluents using biochars produced at different pyrolytic temperatures.

PubMed

Li, Helian; Qu, Ronghui; Li, Chao; Guo, Weilin; Han, Xuemei; He, Fang; Ma, Yibing; Xing, Baoshan

2014-07-01

Wheat straw biochars produced at 400, 600 and 800°C (BC400, BC600 and BC800) were used to selectively adsorb PAHs from soil washing effluents. For soil washing effluents contained Phenanthrene (PHE), Fluoranthene (FLU), Pyrene (PYR) and Triton X-100 (TX100), biochars at 2 (for BC800) or 6 g L(-1) (for BC400 and BC600) can remove 71.8-98.6% of PAHs while recover more than 87% of TX100. PAH removals increase with increasing biochar dose. However, excess biochar is detrimental to the recovery of surfactant. For a specific biochar dose, PAH removal and TX100 loss increase with increasing pyrolytic temperature. For BC400 and BC600, PAH removal follows the order of PHE>FLU>PYR, while the order is reversed with PYR>FLU>PHE for BC800. Biochars have much higher sorption affinity for PAHs than for TX100. It is therefore suggested that biochar is a good alternative for selective adsorption of PAHs and recovery of TX100 in soil washing process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Functionalization of Graphene Nanoplatelets on the Mechanical and Thermal Properties of Silicone Rubber Composites

PubMed Central

Zhang, Guangwu; Wang, Fuzhong; Dai, Jing; Huang, Zhixiong

2016-01-01

This study investigated the effect of silane and surfactant treatments of graphene nanoplatelets (GnPs) on the mechanical and thermal properties of silicone rubber (SR) composites. GnPs were modified with aminopropyltriethoxysilane (APTES), vinyltrimethoxysilane (VTMS), and Triton X-100, and then the pristine GnPs and functionalized GnPs were individually incorporated into the SR. Compared with the pristine GnP/SR composite, the composites reinforced with modified GnP showed better tensile strength, elongation at break, and thermal conductivity properties due to better dispersion of modified GnPs and stronger interfacial interactions between the modified GnPs and matrix. The mechanical properties and thermal conductivity of the VTMS-GnP/SR composite were comparable to the properties of the Triton-GnP counterpart, but better than that of the APTES-GnP/SR composite. In addition, the VTMS-GnP/SR composite demonstrated the highest thermal stability and crystallization temperature among the four types of composites. The remarkable improvement of mechanical and thermal properties of the VTMS-GnP/SR composite was mainly due to the covalent linkage of VTMS-GnP with SR. The VTMS treatment was a more appropriate modification of GnP particles to improve the multifunctional properties of SR. PMID:28787891

Effect of Functionalization of Graphene Nanoplatelets on the Mechanical and Thermal Properties of Silicone Rubber Composites.

PubMed

Zhang, Guangwu; Wang, Fuzhong; Dai, Jing; Huang, Zhixiong

2016-02-02

This study investigated the effect of silane and surfactant treatments of graphene nanoplatelets (GnPs) on the mechanical and thermal properties of silicone rubber (SR) composites. GnPs were modified with aminopropyltriethoxysilane (APTES), vinyltrimethoxysilane (VTMS), and Triton X-100, and then the pristine GnPs and functionalized GnPs were individually incorporated into the SR. Compared with the pristine GnP/SR composite, the composites reinforced with modified GnP showed better tensile strength, elongation at break, and thermal conductivity properties due to better dispersion of modified GnPs and stronger interfacial interactions between the modified GnPs and matrix. The mechanical properties and thermal conductivity of the VTMS-GnP/SR composite were comparable to the properties of the Triton-GnP counterpart, but better than that of the APTES-GnP/SR composite. In addition, the VTMS-GnP/SR composite demonstrated the highest thermal stability and crystallization temperature among the four types of composites. The remarkable improvement of mechanical and thermal properties of the VTMS-GnP/SR composite was mainly due to the covalent linkage of VTMS-GnP with SR. The VTMS treatment was a more appropriate modification of GnP particles to improve the multifunctional properties of SR.

Determination of cadmium(II), cobalt(II), nickel(II), lead(II), zinc(II), and copper(II) in water samples using dual-cloud point extraction and inductively coupled plasma emission spectrometry.

PubMed

Zhao, Lingling; Zhong, Shuxian; Fang, Keming; Qian, Zhaosheng; Chen, Jianrong

2012-11-15

A dual-cloud point extraction (d-CPE) procedure has been developed for simultaneous pre-concentration and separation of heavy metal ions (Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ion) in water samples by inductively coupled plasma optical emission spectrometry (ICP-OES). The procedure is based on forming complexes of metal ion with 8-hydroxyquinoline (8-HQ) into the as-formed Triton X-114 surfactant rich phase. Instead of direct injection or analysis, the surfactant rich phase containing the complexes was treated by nitric acid, and the detected ions were back extracted again into aqueous phase at the second cloud point extraction stage, and finally determined by ICP-OES. Under the optimum conditions (pH=7.0, Triton X-114=0.05% (w/v), 8-HQ=2.0×10(-4) mol L(-1), HNO3=0.8 mol L(-1)), the detection limits for Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ions were 0.01, 0.04, 0.01, 0.34, 0.05, and 0.04 μg L(-1), respectively. Relative standard deviation (RSD) values for 10 replicates at 100 μg L(-1) were lower than 6.0%. The proposed method could be successfully applied to the determination of Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Cu2+ ion in water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

A non-chromatographic method for the removal of endotoxins from bacteriophages.

PubMed

Branston, Steven D; Wright, Jason; Keshavarz-Moore, Eli

2015-08-01

The Ff filamentous bacteriophages show potential as a new class of therapeutics, displaying utility in materials science as well as pharmaceutical applications. These phages are produced by the infection of E. coli, a Gram-negative bacterium which unavoidably sheds endotoxins into the extracellular space during growth. Since endotoxin molecules are highly immunoreactive, separation from the phage product is of critical importance, particularly those developed for human therapeutic use. The properties of M13, one of the Ff group, present a purification challenge chiefly because the standard scalable method for endotoxin removal from proteins-anion exchange chromatography-is not applicable due to pI similarity between the particles. This article examines the potential of polyethylene glycol (PEG)-NaCl precipitation as a scalable method for the separation of endotoxins from phage M13. Precipitation of M13 by 2% (w/v) PEG 6 000, 500 mM NaCl reduced endotoxin contamination of the phage product by 88%, but additional precipitation rounds did not maintain this proportional decrease. Dynamic light scattering was subsequently used to determine the effectiveness of a detergent to disassociate endotoxin molecules from M13. As a result, PEG-NaCl precipitation was supplemented with up to 2% (v/v) Triton X-100 to improve separation. A 5.7 log10 reduction in endotoxin concentration was achieved over three rounds of precipitation whilst retaining over 97% of the phage. This method compares favorably with the well-known ATPS (Triton X-114) technique for endotoxin removal from protein solutions. © 2015 Wiley Periodicals, Inc.

Purification and Identification of Membrane Proteins from Urinary Extracellular Vesicles using Triton X-114 Phase Partitioning.

PubMed

Hu, Shuiwang; Musante, Luca; Tataruch, Dorota; Xu, Xiaomeng; Kretz, Oliver; Henry, Michael; Meleady, Paula; Luo, Haihua; Zou, Hequn; Jiang, Yong; Holthofer, Harry

2018-01-05

Urinary extracellular vesicles (uEVs) have become a promising source for biomarkers accurately reflecting biochemical changes in kidney and urogenital diseases. Characteristically, uEVs are rich in membrane proteins associated with several cellular functions like adhesion, transport, and signaling. Hence, membrane proteins of uEVs should represent an exciting protein class with unique biological properties. In this study, we utilized uEVs to optimize the Triton X-114 detergent partitioning protocol targeted for membrane proteins and proceeded to their subsequent characterization while eliminating effects of Tamm-Horsfall protein, the most abundant interfering protein in urine. This is the first report aiming to enrich and characterize the integral transmembrane proteins present in human urinary vesicles. First, uEVs were enriched using a "hydrostatic filtration dialysis'' appliance, and then the enriched uEVs and lysates were verified by transmission electron microscopy. After using Triton X-114 phase partitioning, we generated an insoluble pellet fraction and aqueous phase (AP) and detergent phase (DP) fractions and analyzed them with LC-MS/MS. Both in- and off-gel protein digestion methods were used to reveal an increased number of membrane proteins of uEVs. After comparing with the identified proteins without phase separation as in our earlier publication, 199 different proteins were detected in DP. Prediction of transmembrane domains (TMDs) from these protein fractions showed that DP had more TMDs than other groups. The analyses of hydrophobicity revealed that the GRAVY score of DP was much higher than those of the other fractions. Furthermore, the analysis of proteins with lipid anchor revealed that DP proteins had more lipid anchors than other fractions. Additionally, KEGG pathway analysis showed that the DP proteins detected participate in endocytosis and signaling, which is consistent with the expected biological functions of membrane proteins. Finally, results of Western blotting confirmed that the membrane protein bands are found in the DP fraction instead of AP. In conclusion, our study validates the use of Triton X-114 phase partitioning protocol on uEVs for a targeted isolation of membrane proteins and to reduce sample complexity. This method successfully facilitates detection of potential biomarkers and druggable targets in uEVs.

Glycosyltransferases in the Golgi membranes of onion stem

PubMed Central

Powell, Janet T.; Brew, Keith

1974-01-01

Cell fractions consisting largely of Golgi membranes were prepared from the meristematic region of the onion. Several enzyme activities were found to be localized in these fractions: inosine diphosphatase, galactosyltransferases and glucosyltransferases. The fractions catalysed the transfer of [14C]galactose from UDP-galactose to endogenous and cell-sap acceptors, to N-acetylglucosamine and to ovalbumin. In the presence of bovine α-lactalbumin, transfer to glucose (lactose synthesis) was catalysed. [14C]Glucose was transferred from UDP-glucose to endogenous and cell-sap acceptors, to cellobiose and to fructose (sucrose synthesis). All these activities were latent, being potentiated by detergents (Triton X-100 or sodium deoxycholate). The characteristics of some of these enzyme activities are described and their biological significance is discussed. ImagesPLATE 1 PMID:4374190

Expression of the Major Surface Antigen of Plasmodium knowlesi Sporozoites in Yeast

NASA Astrophysics Data System (ADS)

Sharma, Shobhona; Godson, G. Nigel

1985-05-01

The circumsporozoite protein, a surface antigen of the sporozoite stage of the monkey malarial parasite Plasmodium knowlesi, was expressed in the yeast Saccharomyces cerevisiae by using an expression vector containing the 5' regulatory region of the yeast alcohol dehydrogenase I gene. It was necessary to eliminate the entire 5' upstream region of the parasite DNA to obtain the expression of this protein. Only the circumsporozoite precursor protein was produced by the yeast transformants, as detected by immunoblotting. About 55 and 20 percent of the circumsporozoite protein produced in yeast was associated with the 25,000g and 150,000g particulate fractions, respectively. The protein could be solubilized in Triton X-100 and was stable in solubilized extracts.

Demonstration of separate phosphotyrosyl- and phosphoseryl- histone phosphatase activities in the plasma membranes of a human astrocytoma.

PubMed

Leis, J F; Knowles, A F; Kaplan, N O

1985-06-01

A plasma membrane preparation from a human astrocytoma contained p-nitrophenyl phosphate (pNPP), phosphotyrosyl histone, and phosphoseryl histone hydrolysis activities. The pNPPase and phosphotyrosyl histone phosphatase activities were inhibited by vanadate, whereas the phosphoseryl histone phosphatase activity was not; the latter activity was inhibited by pyrophosphate and nucleoside di- and triphosphates. When the membranes were solubilized by Triton X-100 and the solubilized proteins were subjected to column chromatography on DEAE-Sephadex, Sepharose 6B-C1, and wheat germ agglutinin-Sepharose 4B columns, the pNPPase activity from the phosphoseryl histone phosphatase activity. The results from column chromatography also indicated that there may be multiple phosphotyrosyl and phosphoseryl protein phosphatases in the plasma membranes.

European Organisation for Research and Treatment of Cancer (EORTC) Pathobiology Group standard operating procedure for the preparation of human tumour tissue extracts suited for the quantitative analysis of tissue-associated biomarkers.

PubMed

Schmitt, Manfred; Mengele, Karin; Schueren, Elisabeth; Sweep, Fred C G J; Foekens, John A; Brünner, Nils; Laabs, Juliane; Malik, Abha; Harbeck, Nadia

2007-03-01

With the new concept of 'individualized treatment and targeted therapies', tumour tissue-associated biomarkers have been given a new role in selection of cancer patients for treatment and in cancer patient management. Tumour biomarkers can give support to cancer patient stratification and risk assessment, treatment response identification, or to identifying those patients who are expected to respond to certain anticancer drugs. As the field of tumour-associated biomarkers has expanded rapidly over the last years, it has become increasingly apparent that a strong need exists to establish guidelines on how to easily disintegrate the tumour tissue for assessment of the presence of tumour tissue-associated biomarkers. Several mechanical tissue (cell) disruption techniques exist, ranging from bead mill homogenisation and freeze-fracturing through to blade or pestle-type homogenisation, to grinding and ultrasonics. Still, only a few directives have been given on how fresh-frozen tumour tissues should be processed for the extraction and determination of tumour biomarkers. The PathoBiology Group of the European Organisation for Research and Treatment of Cancer therefore has devised a standard operating procedure for the standardised preparation of human tumour tissue extracts which is designed for the quantitative analysis of tumour tissue-associated biomarkers. The easy to follow technical steps involved require 50-300 mg of deep-frozen cancer tissue placed into small size (1.2 ml) cryogenic tubes. These are placed into the shaking flask of a Mikro-Dismembrator S machine (bead mill) to pulverise the tumour tissue in the capped tubes in the deep-frozen state by use of a stainless steel ball, all within 30 s of exposure. RNA is isolated from the pulverised tissue following standard procedures. Proteins are extracted from the still frozen pulverised tissue by addition of Tris-buffered saline to obtain the cytosol fraction of the tumour or by the Tris buffer supplemented with the non-ionic detergent Triton X-100, and, after high-speed centrifugation, are found in the tissue supernatant. The resulting tissue cell debris sediment is a rich source of genomic DNA.

Development of an Efficient Protein Extraction Method Compatible with LC-MS/MS for Proteome Mapping in Two Australian Seagrasses Zostera muelleri and Posidonia australis

PubMed Central

Jiang, Zhijian; Kumar, Manoj; Padula, Matthew P.; Pernice, Mathieu; Kahlke, Tim; Kim, Mikael; Ralph, Peter J.

2017-01-01

The availability of the first complete genome sequence of the marine flowering plant Zostera marina (commonly known as seagrass) in early 2016, is expected to significantly raise the impact of seagrass proteomics. Seagrasses are marine ecosystem engineers that are currently declining worldwide at an alarming rate due to both natural and anthropogenic disturbances. Seagrasses (especially species of the genus Zostera) are compromised for proteomic studies primarily due to the lack of efficient protein extraction methods because of their recalcitrant cell wall which is rich in complex polysaccharides and a high abundance of secondary metabolites in their cells. In the present study, three protein extraction methods that are commonly used in plant proteomics i.e., phenol (P); trichloroacetic acid/acetone/SDS/phenol (TASP); and borax/polyvinyl-polypyrrolidone/phenol (BPP) extraction, were evaluated quantitatively and qualitatively based on two dimensional isoelectric focusing (2D-IEF) maps and LC-MS/MS analysis using the two most abundant Australian seagrass species, namely Zostera muelleri and Posidonia australis. All three tested methods produced high quality protein extracts with excellent 2D-IEF maps in P. australis. However, the BPP method produces better results in Z. muelleri compared to TASP and P. Therefore, we further modified the BPP method (M-BPP) by homogenizing the tissue in a modified protein extraction buffer containing both ionic and non-ionic detergents (0.5% SDS; 1.5% Triton X-100), 2% PVPP and protease inhibitors. Further, the extracted proteins were solubilized in 0.5% of zwitterionic detergent (C7BzO) instead of 4% CHAPS. This slight modification to the BPP method resulted in a higher protein yield, and good quality 2-DE maps with a higher number of protein spots in both the tested seagrasses. Further, the M-BPP method was successfully utilized in western-blot analysis of phosphoenolpyruvate carboxylase (PEPC—a key enzyme for carbon metabolism). This optimized protein extraction method will be a significant stride toward seagrass proteome mining and identifying the protein biomarkers to stress response of seagrasses under the scenario of global climate change and anthropogenic perturbations. PMID:28861098

Development of an Efficient Protein Extraction Method Compatible with LC-MS/MS for Proteome Mapping in Two Australian Seagrasses Zostera muelleri and Posidonia australis.

PubMed

Jiang, Zhijian; Kumar, Manoj; Padula, Matthew P; Pernice, Mathieu; Kahlke, Tim; Kim, Mikael; Ralph, Peter J

2017-01-01

The availability of the first complete genome sequence of the marine flowering plant Zostera marina (commonly known as seagrass) in early 2016, is expected to significantly raise the impact of seagrass proteomics. Seagrasses are marine ecosystem engineers that are currently declining worldwide at an alarming rate due to both natural and anthropogenic disturbances. Seagrasses (especially species of the genus Zostera ) are compromised for proteomic studies primarily due to the lack of efficient protein extraction methods because of their recalcitrant cell wall which is rich in complex polysaccharides and a high abundance of secondary metabolites in their cells. In the present study, three protein extraction methods that are commonly used in plant proteomics i.e., phenol (P); trichloroacetic acid/acetone/SDS/phenol (TASP); and borax/polyvinyl-polypyrrolidone/phenol (BPP) extraction, were evaluated quantitatively and qualitatively based on two dimensional isoelectric focusing (2D-IEF) maps and LC-MS/MS analysis using the two most abundant Australian seagrass species, namely Zostera muelleri and Posidonia australis . All three tested methods produced high quality protein extracts with excellent 2D-IEF maps in P. australis . However, the BPP method produces better results in Z. muelleri compared to TASP and P. Therefore, we further modified the BPP method (M-BPP) by homogenizing the tissue in a modified protein extraction buffer containing both ionic and non-ionic detergents (0.5% SDS; 1.5% Triton X-100), 2% PVPP and protease inhibitors. Further, the extracted proteins were solubilized in 0.5% of zwitterionic detergent (C7BzO) instead of 4% CHAPS. This slight modification to the BPP method resulted in a higher protein yield, and good quality 2-DE maps with a higher number of protein spots in both the tested seagrasses. Further, the M-BPP method was successfully utilized in western-blot analysis of phosphoenolpyruvate carboxylase (PEPC-a key enzyme for carbon metabolism). This optimized protein extraction method will be a significant stride toward seagrass proteome mining and identifying the protein biomarkers to stress response of seagrasses under the scenario of global climate change and anthropogenic perturbations.

A Simple and Selective Spectrophotometric Method for the Determination of Trace Gold in Real, Environmental, Biological, Geological and Soil Samples Using Bis (Salicylaldehyde) Orthophenylenediamine

PubMed Central

Soomro, Rubina; Ahmed, M. Jamaluddin; Memon, Najma; Khan, Humaira

2008-01-01

A simple high sensitive, selective, and rapid spectrophotometric method for the determination of trace gold based on the rapid reaction of gold(III) with bis(salicylaldehyde)orthophenylenediamine (BSOPD) in aqueous and micellar media has been developed. BSOPD reacts with gold(III) in slightly acidic solution to form a 1:1 brownish-yellow complex, which has an maximum absorption peak at 490 nm in both aqueous and micellar media. The most remarkable point of this method is that the molar absorptivities of the gold-BSOPD complex form in the presence of the nonionic TritonX-100 surfactant are almost a 10 times higher than the value observed in the aqueous solution, resulting in an increase in the sensitivity and selectivity of the method. The apparent molar absorptivities were found to be 2.3 × 104 L mol−1 cm−1 and 2.5 × 105 L mol−1 cm−1 in aqueous and micellar media, respectively. The reaction is instantaneous and the maximum absorbance was obtained after 10 min at 490 nm and remains constant for over 24 h at room temperature. The linear calibration graphs were obtained for 0.1–30 mg L−1 and 0.01–30 mg L−1 of gold(III) in aqueous and surfactant media, respectively. The interference from over 50 cations, anions and complexing agents has been studied at 1 mg L−1 of Au(III); most metal ions can be tolerated in considerable amounts in aqueous micellar solutions. The Sandell’s sensitivity, the limit of detection and relative standard deviation (n = 9) were found to be 5 ng cm−2, 1 ng mL−1 and 2%, respectively in aqueous micellar solutions. Its sensitivity and selectivity are remarkably higher than that of other reagents in the literature. The proposed method was successfully used in the determination of gold in several standard reference materials (alloys and steels), environmental water samples (potable and polluted), and biological samples (blood and urine), geological, soil and complex synthetic mixtures. The results obtained agree well with those samples analyzed by atomic absorption spectrophotometry (AAS). PMID:19609392

Results from prototype die-to-database reticle inspection system

NASA Astrophysics Data System (ADS)

Mu, Bo; Dayal, Aditya; Broadbent, Bill; Lim, Phillip; Goonesekera, Arosha; Chen, Chunlin; Yeung, Kevin; Pinto, Becky

2009-03-01

A prototype die-to-database high-resolution reticle defect inspection system has been developed for 32nm and below logic reticles, and 4X Half Pitch (HP) production and 3X HP development memory reticles. These nodes will use predominantly 193nm immersion lithography (with some layers double patterned), although EUV may also be used. Many different reticle types may be used for these generations including: binary (COG, EAPSM), simple tritone, complex tritone, high transmission, dark field alternating (APSM), mask enhancer, CPL, and EUV. Finally, aggressive model based OPC is typically used, which includes many small structures such as jogs, serifs, and SRAF (sub-resolution assist features), accompanied by very small gaps between adjacent structures. The architecture and performance of the prototype inspection system is described. This system is designed to inspect the aforementioned reticle types in die-todatabase mode. Die-to-database inspection results are shown on standard programmed defect test reticles, as well as advanced 32nm logic, and 4X HP and 3X HP memory reticles from industry sources. Direct comparisons with currentgeneration inspection systems show measurable sensitivity improvement and a reduction in false detections.

Stellar Occultation Probe of Triton's Atmosphere

NASA Technical Reports Server (NTRS)

Elliot, James L.

1998-01-01

The goals of this research were (i) to better characterize Triton's atmospheric structure by probing a region not well investigated by Voyager and (ii) to begin acquiring baseline data for an investigation of the time evolution of the atmosphere which will set limits on the thermal conductivity of the surface and the total mass of N2 in the atmosphere. Our approach was to use observations (with the Kuiper Airborne Observatory) of a stellar occultation by Triton that was predicted to occur on 1993 July 10. As described in the attached reprint, we achieved these objectives through observation of this occultation and a subsequent one with the KAO in 1995. We found new results about Triton's atmospheric structure from the analysis of the two occultations observed with the KAO and ground-based data. These stellar occultation observations made both in the visible and infrared, have good spatial coverage of Triton including the first Triton central-flash observations, and are the first data to probe the 20-100 km altitude level on Triton. The small-planet light curve model of Elliot and Young (AJ 103, 991-1015) was generalized to include stellar flux refracted by the far limb, and then fitted to the data. Values of the pressure, derived from separate immersion and emersion chords, show no significant trends with latitude indicating that Triton's atmosphere is spherically symmetric at approximately 50 km altitude to within the error of the measurements. However, asymmetry observed in the central flash indicates the atmosphere is not homogeneous at the lowest levels probed (approximately 20 km altitude). From the average of the 1995 occultation data, the equivalent-isothermal temperature of the atmosphere is 47 +/- 1 K and the atmospheric pressure at 1400 km radius (approximately 50 km altitude) is 1.4 +/- 0.1 microbar. Both of these are not consistent with a model based on Voyager UVS and RSS observations in 1989 (Strobel et al, Icarus 120, 266-289). The atmospheric temperature from the occultation is 5 K colder than that predicted by the model and the observed pressure is a factor of 1.8 greater than the model.

Acetylcholinesterase from Apis mellifera head. Evidence for amphiphilic and hydrophilic forms characterized by Triton X-114 phase separation.

PubMed Central

Belzunces, L P; Toutant, J P; Bounias, M

1988-01-01

The polymorphism of bee acetylcholinesterase was studied by sucrose-gradient-sedimentation analysis and non-denaturing electrophoretic analysis of fresh extracts. Lubrol-containing extracts exhibited only one form, which sedimented at 5 S when analysed on high-salt Lubrol-containing gradients and 6 S when analysed on low-salt Lubrol-containing gradients. The 5 S/6 S form aggregated upon removal of the detergent when sedimented on detergent-free gradients and was recovered in the detergent phase after Triton X-114 phase separation. Thus the 5 S/6 S enzyme corresponds to an amphiphilic acetylcholinesterase form. In detergent-free extracts three forms, whose apparent sedimentation coefficients are 14 S, 11 S and 7 S, were observed when sedimentations were performed on detergent-free gradients. Sedimentation analyses on detergent-containing gradients showed only a 5 S peak in high-salt detergent-free extracts and a 6 S peak, with a shoulder at about 7 S, in low-salt detergent-free extracts. Electrophoretic analysis in the presence of detergent demonstrated that the 14 S and 11 S peaks corresponded to aggregates of the 5 S/6 S form, whereas the 7 S peak corresponded to a hydrophilic acetylcholinesterase form which was recovered in the aqueous phase following Triton X-114 phase separation. The 5 S/6 S amphiphilic form could be converted into a 7.1 S hydrophilic form by phosphatidylinositol-specific phospholipase C digestion. Images Fig. 3. Fig. 6. PMID:2849414

Investigation of X-ray permeability of surgical gloves coated with different contrast agents

PubMed Central

Kayan, Mustafa; Yaşar, Selçuk; Saygın, Mustafa; Yılmaz, Ömer; Aktaş, Aykut Recep; Kayan, Fatmanur; Türker, Yasin; Çetinkaya, Gürsel

2016-01-01

Objective: We aimed to investigate the effectiveness and radiation protection capability of latex gloves coated with various contrast agents as an alternative to lead gloves. Methods: The following six groups were created to evaluate the permeability of X-ray in this experimental study: lead gloves, two different non-ionic contrast media (iopromide 370/100 mg I/mL and iomeprol 400/100 mg I/mL), 10% povidone–iodine (PV–I), 240/240 g/mL barium sulphate and a mixture of equal amounts of all contrast agents. A radiation dose detector was placed in coated latex gloves for each one. The absorption values of radiation from latex gloves coated with various contrast agents were measured and compared with the absorption of radiation from lead gloves. This study was designed as an ‘experimental study’. Results: The mean absorption value of X-ray from lead gloves was 3.0±0.08 µG/s. The mean absorption values of X-ray from latex gloves coated with various contrast agents were 3.7±0.09 µG/s (iopromide 370/100 mg I/mL), 3.6±0.09 µG/s (iomeprol 400/100 mg I/mL), 3.7±0.04 µG/s (PV–I), 3.1±0.07 µG/s (barium sulphate) and 3.8±0.05 µG/s (mixture of all contrast agents). Latex gloves coated with barium sulphate provided the best radiation absorption compared with latex gloves coated with other radiodense contrast agents. Conclusion: Latex gloves coated with barium sulphate may provide protection equivalent to lead gloves. PMID:26680548

Purification and Characterization of 1-Aminocyclopropane-1-Carboxylate Synthase from Apple Fruits 1

PubMed Central

Yip, Wing-Kin; Dong, Jian-Guo; Yang, Shang Fa

1991-01-01

1-Aminocyclopropane-1-carboxylate (ACC) synthase, a key enzyme in ethylene biosynthesis, was isolated and partially purified from apple (Malus sylvestris Mill.) fruits. Unlike ACC synthase isolated from other sources, apple ACC synthase is associated with the pellet fraction and can be solubilized in active form with Triton X-100. Following five purification steps, the solubilized enzyme was purified over 5000-fold to a specific activity of 100 micromoles per milligram protein per hour, and its purity was estimated to be 20 to 30%. Using this preparation, specific monoclonal antibodies were raised. Monoclonal antibodies against ACC synthase immunoglobulin were coupled to protein-A agarose to make an immunoaffinity column, which effectively purified the enzyme from a relatively crude enzyme preparation (100 units per milligram protein). As with the tomato enzyme, apple ACC synthase was inactivated and radiolabeled by its substrate S-adenosyl-l-methionine. Apple ACC synthase was identified to be a 48-kilodalton protein based on the observation that it was specifically bound to immunoaffinity column and it was specifically radiolabeled by its substrate S-adenosyl-l-methionine. Images Figure 4 Figure 6 PMID:16667960

Cloud point extraction and flame atomic absorption spectrometric determination of cadmium and nickel in drinking and wastewater samples.

PubMed

Naeemullah; Kazi, Tasneem G; Shah, Faheem; Afridi, Hassan I; Baig, Jameel Ahmed; Soomro, Abdul Sattar

2013-01-01

A simple method for the preconcentration of cadmium (Cd) and nickel (Ni) in drinking and wastewater samples was developed. Cloud point extraction has been used for the preconcentration of both metals, after formation of complexes with 8-hydroxyquinoline (8-HQ) and extraction with the surfactant octylphenoxypolyethoxyethanol (Triton X-114). Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the Cd and Ni contents were measured by flame atomic absorption spectrometry. The experimental variables, such as pH, amounts of reagents (8-HQ and Triton X-114), temperature, incubation time, and sample volume, were optimized. After optimization of the complexation and extraction conditions, enhancement factors of 80 and 61, with LOD values of 0.22 and 0.52 microg/L, were obtained for Cd and Ni, respectively. The proposed method was applied satisfactorily for the determination of both elements in drinking and wastewater samples.

Graphite furnace atomic absorption spectrometric determination of vanadium after cloud point extraction in the presence of graphene oxide

NASA Astrophysics Data System (ADS)

López-García, Ignacio; Marín-Hernández, Juan José; Hernández-Córdoba, Manuel

2018-05-01

Vanadium (V) and vanadium (IV) in the presence of a small concentration of graphene oxide (0.05 mg mL-1) are quantitatively transferred to the coacervate obtained with Triton X-114 in a cloud point microextraction process. The surfactant-rich phase is directly injected into the graphite atomizer of an atomic absorption spectrometer. Using a 10-mL aliquot sample and 150 μL of a 15% Triton X-114 solution, the enrichment factor for the analyte is 103, which results in a detection limit of 0.02 μg L-1 vanadium. The separation of V(V) and V(IV) using an ion-exchanger allows speciation of the element at low concentrations. Data for seven reference water samples with certified vanadium contents confirm the reliability of the procedure. Several beer samples are also analyzed, those supplied as canned drinks showing low levels of tetravalent vanadium.

Cloud point extraction thermospray flame quartz furnace atomic absorption spectrometry for determination of ultratrace cadmium in water and urine

NASA Astrophysics Data System (ADS)

Wu, Peng; Zhang, Yunchang; Lv, Yi; Hou, Xiandeng

2006-12-01

A simple, low cost and highly sensitive method based on cloud point extraction (CPE) for separation/preconcentration and thermospray flame quartz furnace atomic absorption spectrometry was proposed for the determination of ultratrace cadmium in water and urine samples. The analytical procedure involved the formation of analyte-entrapped surfactant micelles by mixing the analyte solution with an ammonium pyrrolidinedithiocarbamate (APDC) solution and a Triton X-114 solution. When the temperature of the system was higher than the cloud point of Triton X-114, the complex of cadmium-PDC entered the surfactant-rich phase and thus separation of the analyte from the matrix was achieved. Under optimal chemical and instrumental conditions, the limit of detection was 0.04 μg/L for cadmium with a sample volume of 10 mL. The analytical results of cadmium in water and urine samples agreed well with those by ICP-MS.

Isolation and reconstitution of cytochrome P450ox and in vitro reconstitution of the entire biosynthetic pathway of the cyanogenic glucoside dhurrin from sorghum.

PubMed Central

Kahn, R A; Bak, S; Svendsen, I; Halkier, B A; Møller, B L

1997-01-01

A cytochrome P450, designated P450ox, that catalyzes the conversion of (Z)-p-hydroxyphenylacetaldoxime (oxime) to p-hydroxymandelonitrile in the biosynthesis of the cyanogenic glucoside beta-D-glucopyranosyloxy-(S)-p-hydroxymandelonitrile (dhurrin), has been isolated from microsomes prepared from etiolated seedlings of sorghum (Sorghum bicolor L. Moench). P450ox was solubilized using nonionic detergents, and isolated by ion-exchange chromatography, Triton X-114 phase partitioning, and dye-column chromatography. P450ox has an apparent molecular mass of 55 kD, its N-terminal amino acid sequence is -ATTATPQLLGGSVP, and it contains the internal sequence MDRLVADLDRAAA. Reconstitution of P450ox with NADPH-P450 oxidoreductase in micelles of L-alpha-dilauroyl phosphatidylcholine identified P450ox as a multifunctional P450 catalyzing dehydration of (Z)-oxime to p-hydroxyphenylaceto-nitrile (nitrile) and C-hydroxylation of p-hydroxyphenylacetonitrile to nitrile. P450ox is extremely labile compared with the P450s previously isolated from sorghum. When P450ox is reconstituted in the presence of a soluble uridine diphosphate glucose glucosyltransferase, oxime is converted to dhurrin. In vitro reconstitution of the entire dhurrin biosynthetic pathway from tyrosine was accomplished by the insertion of CYP79 (tyrosine N-hydroxylase), P450ox, and NADPH-P450 oxidoreductase in lipid micelles in the presence of uridine diphosphate glucose glucosyltransferase. The catalysis of the conversion of Tyr into nitrile by two multifunctional P450s explains why all intermediates in this pathway except (Z)-oxime are channeled. PMID:9414567

Identification of a melanosomal membrane protein encoded by the pink-eyed dilution (type II oculocutaneous albinism) gene.

PubMed Central

Rosemblat, S; Durham-Pierre, D; Gardner, J M; Nakatsu, Y; Brilliant, M H; Orlow, S J

1994-01-01

The pink-eyed dilution (p) locus in the mouse is critical to melanogenesis; mutations in the homologous locus in humans, P, are a cause of type II oculocutaneous albinism. Although a cDNA encoded by the p gene has recently been identified, nothing is known about the protein product of this gene. To characterize the protein encoded by the p gene, we performed immunoblot analysis of extracts of melanocytes cultured from wild-type mice with an antiserum from rabbits immunized with a peptide corresponding to amino acids 285-298 of the predicted protein product of the murine p gene. This antiserum recognized a 110-kDa protein. The protein was absent from extracts of melanocytes cultured from mice with two mutations (pcp and p) in which transcripts of the p gene are absent or greatly reduced. Introduction of the cDNA for the p gene into pcp melanocytes by electroporation resulted in expression of the 3.3-kb mRNA and the 110-kDa protein. Upon subcellular fractionation of cultured melanocytes, the 110-kDa protein was found to be present in melanosomes but absent from the vesicular fraction; phase separation performed with the nonionic detergent Triton X-114 confirmed the predicted hydrophobic nature of the protein. These results demonstrate that the p gene encodes a 110-kDa integral melanosomal membrane protein and establish a framework by which mutations at this locus, which diminish pigmentation, can be analyzed at the cellular and biochemical levels. Images PMID:7991586

Nonionic amphiphile nanoarchitectonics: self-assembly into micelles and lyotropic liquid crystals

NASA Astrophysics Data System (ADS)

Shrestha, Lok Kumar; Strzelczyk, Karolina Maria; Goswami Shrestha, Rekha; Ichikawa, Kotoko; Aramaki, Kenji; Hill, Jonathan P.; Ariga, Katsuhiko

2015-05-01

Amphiphiles, molecules that possess both hydrophilic and hydrophobic moieties, are architecturally simple molecules that can spontaneously self-assemble into complex hierarchical structures from lower to higher dimensions either in the bulk phase or at an interface. Recent developments in multifunctional nanostructure design using the advanced concept of nanoarchitectonics utilize this simple process of assembly. Amphiphilic self-assemblies involving lipids or proteins mimic the structure of biological systems, thus highlighting the necessity of a fundamental physical understanding of amphiphilic self-assembly towards a realization of the complex mechanisms operating in nature. Herein, we describe self-assembled microstructures of biocompatible and biodegradable tetraglycerol lauryl ether (C12G4) nonionic surfactant in an aqueous solvent system. Temperature-composition analyses of equilibrium phases identified by using small-angle x-ray scattering (SAXS) provide strong evidence of various spontaneously self-assembled mesostructures, such as normal micelles (Wm), hexagonal liquid crystal (H1), and reverse micelles (Om). In contrast to conventional poly(oxyethylene) nonionic surfactants, C12G4 did not exhibit the clouding phenomenon at higher temperatures (phase separation was not observed up to 100 °C), demonstrating the greater thermal stability of the self-assembled mesophases. Generalized indirect Fourier transformation (GIFT) evaluation of the SAXS data confirmed the formation of core-shell-type spherical micelles with a maximum dimension ca. 8.7 nm. The shape and size of the C12G4 micelles remained apparently unchanged over a wide range of concentrations (up to 20%), but intermicellar interactions increased and could be described by the Percus-Yevick (PY) theory (after Carnahan and Starling), which provides a very accurate analytical expression for the osmotic pressure of a monodisperse hard sphere.

Phytoextraction of cadmium by Ipomoea aquatica (water spinach) in hydroponic solution: effects of cadmium speciation.

PubMed

Wang, Kai-Sung; Huang, Lung-Chiu; Lee, Hong-Shen; Chen, Pai-Ye; Chang, Shih-Hsien

2008-06-01

Phytoextraction is a promising technique to remediate heavy metals from contaminated wastewater. However, the interactions of multi-contaminants are not fully clear. This study employed cadmium, Triton X-100 (TX-100), and EDTA to investigate their interactions on phytotoxicity and Cd phytoextraction of Ipomoea aquatica (water spinach) in simulated wastewater. The Cd speciation was estimated by a chemical equilibrium model and MINEQL+. Statistic regression was applied to evaluate Cd speciation on Cd uptake in shoots and stems of I. aquatica. Results indicated that the root length was a more sensitive parameter than root weight and shoot weight. Root elongation was affected by Cd in the Cd-EDTA solution and TX-100 in the Cd-TX-100 solution. Both the root length and the root biomass were negatively correlated with the total soluble Cd ions. In contrast, Cd phytoextraction of I. aquatic was correlated with the aqueous Cd ions in the free and complex forms rather than in the chelating form. Additionally, the high Cd bioconcentration factors of I. aquatica (375-2227 l kg(-1) for roots, 45-144 l kg(-1) for shoots) imply that I. aquatica is a potential aquatic plant to remediate Cd-contaminated wastewater.

Differential incorporation of docosahexaenoic acid into distinct cholesterol-rich membrane raft domains.

PubMed

Duraisamy, Yasotha; Lambert, Daniel; O'Neill, Catherine A; Padfield, Philip J

2007-09-07

We investigated the influence of docosahexaenoic acid (DHA) on the fatty acid and protein compositions of two populations of membrane rafts present in Caco-2 cells. DHA (100 microM) had no significant influence on the fatty acid or protein compositions of tight junction-associated, Lubrol insoluble, membrane rafts. However, DHA did significantly alter the fatty acid and protein compositions of "archetypal" Triton X-100 insoluble membrane rafts. The DHA content of the raft lipids increased 25-fold and was accompanied by a redistribution of src and fyn out of the rafts. DHA also increased Caco-2 cell monolayer permeability producing a 95% drop in transepithelial electrical resistance and a 8.56-fold increase in the flux of dextran. In conclusion, the data demonstrate that DHA does not increase permeability through modifying the TJ-associated rafts. The data do, however, show that DHA is differentially incorporated into different classes of membrane rafts, which has significant implications to our understanding of how omega-3 PUFAs modulate plasma membrane organization and cell function.

Recovery of Extracellular Lipolytic Enzymes from Macrophomina phaseolina by Foam Fractionation with Air

PubMed Central

Germani, José Carlos

2013-01-01

Macrophomina phaseolina was cultivated in complex and simple media for the production of extracellular lipolytic enzymes. Culture supernatants were batch foam fractionated for the recovery of these enzymes, and column design and operation included the use of P 2 frit (porosity 40 to 100 μm), air as sparging gas at variable flow rates, and Triton X-100 added at the beginning or gradually in aliquots. Samples taken at intervals showed the progress of the kinetic and the efficiency parameters. Best results were obtained with the simple medium supernatant by combining the stepwise addition of small amounts of the surfactant with the variation of the air flow rates along the separation. Inert proteins were foamed out first, and the subsequent foamate was enriched in the enzymes, showing estimated activity recovery (R), enrichment ratio (E), and purification factor (P) of 45%, 34.7, and 2.9, respectively. Lipases were present in the enriched foamate. PMID:23738054

Thermal stability and haemolytic effects of depolymerized guar gum derivatives.

PubMed

Hussain, Majid; Zahoor, Tahir; Akhtar, Saeed; Ismail, Amir; Hameed, Aneela

2018-03-01

The purpose of current study was to purify and partially depolymerize guar gum by β-mannanase, HCl, Ba(OH) 2 actions and subjected to inspect compositional, thermogravimetric analysis (TGA) and haemolytic activity. Chemical composition revealed mannose and galactose ratio remained un-altered even after process of purification and hydrolysis. TGA thermograms affirmed initial and final decomposition temperature in various zones. Major decomposition stages apparently revealed partially hydrolyzed guar gum (PHGG) exhibited better heat stable properties having more zones of degradation than crude one. Furthermore, all guar fractions (2.5-250 mg/mL) were subjected to haemolysis to evaluate toxic effects during process of hydrolysis. The crude and hydrolyzed guar galactomannans exhibited minor haemolytic activity (1.9 ± 0.03-7.24 ± 0.02%) when compared to 0.1% Triton-X 100 (100% haemolysis) showing no toxic effects to human RBC's. Conclusively, hydrolyzed guar-galactomannans are safe and can be used in food products with improved heat stability.

Kinetic Tetrazolium Microtiter Assay

NASA Technical Reports Server (NTRS)

Pierson, Duane L.; Stowe, Raymond; Koenig, David

1993-01-01

Kinetic tetrazolium microtiter assay (KTMA) involves use of tetrazolium salts and Triton X-100 (or equivalent), nontoxic, in vitro color developer solubilizing colored metabolite formazan without injuring or killing metabolizing cells. Provides for continuous measurement of metabolism and makes possible to determine rate of action of antimicrobial agent in real time as well as determines effective inhibitory concentrations. Used to monitor growth after addition of stimulatory compounds. Provides for kinetic determination of efficacy of biocide, greatly increasing reliability and precision of results. Also used to determine relative effectiveness of antimicrobial agent as function of time. Capability of generating results on day of test extremely important in treatment of water and waste, disinfection of hospital rooms, and in pharmaceutical, agricultural, and food-processing industries. Assay also used in many aspects of cell biology.

A method for the routine determination of aluminium in serum and water by flameless atomic absorption spectrometry.

PubMed

Parkinson, I S; Ward, M K; Kerr, D N

1982-10-27

A simple but reliable method for the routine determination of aluminium in serum and water by flameless atomic absorption spectrometry is described. No preparatory procedures are required for water samples, although serum is mixed with a wetting agent (Triton X-100) to allow complete combustion of the samples and to improve analytical precision. Precautions to prevent contamination during sample handling are discussed and instrumental parameters are defined. The method has a sensitivity of 35.5 pg and detection limits of 2.3 micrograms Al/l for serum and 1.3 micrograms Al/l for water. The method was used to determine the aluminium concentration in serum of 46 normal subjects. The mean aluminium content was 7.3 micrograms/l (range 2--15 micrograms/l.

Effects of surfactants on fluoranthene mineralization by Sphingomonas paucimobilis strain EPA 505

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lantz, S.; Mueller, J.G.; Lin, J.E.

Past results from surfactant-enriched biodegradation studies have been equivocal because of inhibitory effects of the surfactants and a poor understanding of the characteristics of PAH-degrading microorganisms that make them responsive to surfactants. The authors have studied the mineralization of {sup 14}C-radiolabeled fluoranthene by high cell masses of Sphingomonas paucimobilis, strain EPA 505, and have shown that initial rates of mineralization can be enhanced by concentrations of the surfactant Triton X-100 as high as 2%. Mass balances are reported that show complete degradation of fluoranthene. The presence of soil stimulated biodegradation of fluoranthene in the same manner as surfactants, presumably becausemore » of increased dissolution rates from soil particulates. The usefulness of this bacterium in the bioremediation of PAH-contaminated soil is discussed.« less

A novel membrane based process to isolate photosystem-I membrane complex from spinach.

PubMed

Liu, Jianguo; Yin, Mengmeng; Wang, Meng; Zhang, Xuefang; Ge, Baosheng; Liu, Shuang; Lu, Jianren; Cui, Zhanfeng

2011-02-01

The isolation of photosystem-I (PS-I) from spinach has been conducted using ultrafiltration with 300 kDa molecular weight cut-off polyethersulfone membranes. The effects of ultrafiltration operating conditions on PS-I activity were optimized using parameter scanning ultrafiltration. These conditions included solution pH, ionic strength, stirring speed, and permeate flux. The effects of detergent (Triton X-100 and n-dodecyl-beta-D-maltoside) concentration on time dependent activity of PS-I were also studied using an O(2) electrode. Under optimized conditions, the PS-I purity obtained in the retentate was about 84% and the activity recovery was greater than 94% after ultrafiltration. To our knowledge, this is the first report of the isolation of a membrane protein using ultrafiltration alone.

ATP-binding cassette transporters are enriched in non-caveolar detergent-insoluble glycosphingolipid-enriched membrane domains (DIGs) in human multidrug-resistant cancer cells.

PubMed

Hinrichs, John W J; Klappe, Karin; Hummel, Ina; Kok, Jan W

2004-02-13

In this study we show that P-glycoprotein in multidrug-resistant 2780AD human ovarian carcinoma cells and multidrug resistance-associated protein 1 in multidrug-resistant HT29col human colon carcinoma cells are predominantly located in Lubrol-based detergent-insoluble glycosphingolipid-enriched membrane domains. This localization is independent of caveolae, since 2780AD cells do not express caveolin-1. Although HT29col cells do express caveolin-1, the ATP-binding cassette transporter and caveolin-1 were dissociated on the basis of differential solubility in Triton X-100 and absence of microscopical colocalization. While both the multidrug resistance-associated protein 1 and caveolin-1 are located in Lubrol-based membrane domains, they occupy different regions of these domains.

Identification and characterization of Vibrio cholerae surface proteins by radioiodination.

PubMed Central

Richardson, K; Parker, C D

1985-01-01

Whole cells and isolated outer membrane from Vibrio cholerae (Classical, Inaba) were radiolabeled with Iodogen or Iodo-beads as catalyst. Radiolabeling of whole cells was shown to be surface specific by sodium dodecyl sulfate-urea polyacrylamide gel electrophoresis of whole cells and cell fractions. Surface-labeled whole cells regularly showed 16 distinguishable protein species, of which nine were found in radiolabeled outer membrane preparations obtained by a lithium chloride-lithium acetate procedure. Eight of these proteins were found in outer membranes prepared by sucrose density gradient centrifugation and Triton X-100 extraction of radiolabeled whole cells. The mobility of several proteins was shown to be affected by temperature, and the major protein species exposed on the cell surface was shown to consist of at least two different peptides. Images PMID:3980099

Enhancement of propyl gallate yield in nonaqueous medium using novel cell-associated tannase of Bacillus massiliensis.

PubMed

Aithal, Mahesh; Belur, Prasanna D

2013-01-01

Enzymatic synthesis of propyl gallate in organic solvent was studied using cell-associated tannase (EC 3.1.1.20) of Bacillus massiliensis. Lyophilized biomass showing tannase activity was used as the biocatalyst. The effects of solvent, surfactant treatment, and bioimprinting on the propyl gallate synthesis were studied and subsequently optimized. Among various solvents, benzene followed by hexane was found to be the most favorable. Treatment of the biocatalyst with Triton X-100 at a lower concentration (0.2% w/v), before lyophilization, increased the propyl gallate yield by 24.5% compared to the untreated biocatalyst. The biocatalyst was imprinted with various concentrations of gallic acid and tannic acid. Biocatalyst imprinted with tannic acid showed 50% enhancement in the propyl gallate yield compared to the non-imprinted biocatalyst.

Metalation of positively charged water soluble mesoporphyrins studied via time-resolved SERRS spectroscopy

NASA Astrophysics Data System (ADS)

Procházka, Marek; Hanzliková, Jana; Štěpánek, Josef; Baumruk, Vladimir

1997-06-01

Time-resolved SERRS spectra of 5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]21 H,23 H-porphine (TMAP) were recorded (using a multichannel Raman spectrometer) in various SERS-active Ag colloid/porphyrin systems. Data treatment based on a factor analysis was used to decompose all the SERRS spectra into two main components: SERRS spectrum of the free base TMAP and that of its Ag metalated form. The metalation kinetics obtained in this way was found to be highly dependent on the presence of phosphate anions, citrate and/or Triton X-100 in the colloidal system. The results are analogous to those previously obtained for 5,10,15,20-tetrakis(1-methyl-4-pyridyl)21 H,23 H-porphine, a porphyrin with a substantially stronger tendency towards metalation.

Isolation of a matrix that binds medial Golgi enzymes

PubMed Central

1994-01-01

Rat liver Golgi stacks were extracted with Triton X-100 at neutral pH. After centrifugation the low speed pellet contained two medial-Golgi enzymes, N-acetylglucosaminyltransferase I and mannosidase II, but no enzymes or markers from other parts of the Golgi apparatus. Both were present in the same structures which appeared, by electron microscopy, to be small remnants of cisternal membranes. The enzymes could be removed by treatment with low salt, leaving behind a salt pellet, which we term the matrix. Removal of salt caused specific re-binding of both enzymes to the matrix, with an apparent dissociation constant of 3 nM for mannosidase II. Re-binding was abolished by pretreatment of intact Golgi stacks with proteinase K, suggesting that the matrix was present between the cisternae. PMID:8106542

The cooperative effect of reduced graphene oxide and Triton X-114 on the electromembrane microextraction efficiency of Pramipexole as a model analyte in urine samples.

PubMed

Fashi, Armin; Khanban, Fatemeh; Yaftian, Mohammad Reza; Zamani, Abbasali

2017-01-01

A new design of electromembrane microextraction coupled with high-performance liquid chromatography was developed for the determination of Pramipexole as a model analyte in urine samples. The presence of reduced graphene oxide in the membrane and Triton X-114 in the donor phase augments the extraction efficiency of Pramipexole by the proposed method. Dispersed reduced graphene oxide in the organic solvent was held in the pores of the fiber wall by capillary forces and sonication. It is possible that the immobilized reduced graphene oxide acts as a sorbent, affording an additional pathway for analyte transportation. Besides, the presence of Triton X-114 in the donor phase promotes effective migration of ionic analytes across the membrane. The parameters influencing the extraction procedure, such as type and concentration of surfactant, type of organic solvent, amount of reduced graphene oxide, sonication time, applied voltage, extraction time, ionic strength, pH of the donor and acceptor solutions, and stirring rate were optimized. The linear working ranges of the method for preconcentration- determination of Pramipexole in water and urine samples were found to be 0.13-1000 and 0.47-1000ngmL -1 with corresponding detection limits of 0.04 and 0.14ngmL -1 , respectively. The proposed method allows achieving enrichment factors of 301 and 265 for preconcentration of the analyte in water and urine samples, respectively. The method was successfully applied for the determination of Pramipexole in the urine samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Application of aqueous two-phase micellar system to improve extraction of adenoviral particles from cell lysate.

PubMed

Molino, João Vitor Dutra; Lopes, André Moreni; Viana Marques, Daniela de Araújo; Mazzola, Priscila Gava; da Silva, Joas Lucas; Hirata, Mario Hiroyuki; Hirata, Rosário Dominguez Crespo; Gatti, Maria Silvia Viccari; Pessoa, Adalberto

2017-12-04

Viral vectors are important in medical approaches, such as disease prevention and gene therapy, and their production depends on efficient prepurification steps. In the present study, an aqueous two-phase micellar system (ATPMS) was evaluated to extract human adenovirus type 5 particles from a cell lysate. Adenovirus was cultured in human embryonic kidney 293 (HEK-293) cells to a concentration of 1.4 × 10 10 particles/mL. Cells were lysed, and the system formed by direct addition of Triton X-114 in a 2 3 full factorial design with center points. The systems were formed with Triton X-114 at a final concentration of 1.0, 6.0, and 11.0% (w/w), cell lysate pH of 6.0, 6.5, and 7.0, and incubation temperatures at 33, 35, and 37 °C. Adenovirus particles recovered from partition phases were measured by qPCR. The best system condition was with 11.0% (w/w) of Triton X-114, a cell lysate pH of 7.0, and an incubation temperature at 33 °C, yielding 3.51 × 10 10 adenovirus particles/mL, which increased the initial adenovirus particles concentration by 2.3-fold, purifying it by 2.2-fold from the cell lysate, and removing cell debris. In conclusion, these results demonstrated that the use of an aqueous two-phase micellar system in the early steps of downstream processing could improve viral particle extraction from cultured cells while integrating clarification, concentration, and prepurification steps. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

[Investigation of non-ionizing radiation hazards from physiotherapy equipment in 16 medical institutions].

PubMed

He, Jia-xi; Zhou, Wei; Qiu, Hai-li; Yang, Guang-tao

2013-12-01

To investigate the non-ionizing radiation hazards from physiotherapy equipment in medical institutions and to explore feasible control measures for occupational diseases. On-site measurement and assessment of ultra-high-frequency radiation, high-frequency electromagnetic field, microwave radiation, and laser radiation were carried out in 16 medical institutions using the methods in the Measurement of Physical Agents in Workplace (GBZ/T189-2007). All the investigated medical institutions failed to take effective protective measures against non-ionizing radiation. Of the 17 ultra-short wave therapy apparatus, 70.6%, 47.1%, and 17.64% had a safe intensity of ultra-high-frequency radiation on the head, chest, and abdomen, respectively. Of the 4 external high-frequency thermotherapy apparatus, 100%, 75%, and 75%had a safe intensity of high-frequency electromagnetic field on the head, chest, and abdomen, respectively. In addition, the intensities of microwave radiation and laser radiation produced by the 18 microwave therapy apparatus and 12 laser therapeutic apparatus met national health standards. There are non-ionizing radiation hazards from physiotherapy equipment in medical institutions, and effective prevention and control measures are necessary.

KIFC3, a microtubule minus end–directed motor for the apical transport of annexin XIIIb–associated Triton-insoluble membranes

PubMed Central

Noda, Yasuko; Okada, Yasushi; Saito, Nobuhito; Setou, Mitsutoshi; Xu, Ying; Zhang, Zheizeng; Hirokawa, Nobutaka

2001-01-01

We have identified and characterized a COOH-terminal motor domain–type kinesin superfamily protein (KIFC), KIFC3, in the kidney. KIFC3 is a minus end–directed microtubule motor protein, therefore it accumulates in regions where minus ends of microtubules assemble. In polarized epithelial cells, KIFC3 is localized on membrane organelles immediately beneath the apical plasma membrane of renal tubular epithelial cells in vivo and polarized MDCK II cells in vitro. Flotation assay, coupled with detergent extraction, demonstrated that KIFC3 is associated with Triton X-100–insoluble membrane organelles, and that it overlaps with apically transported TGN-derived vesicles. This was confirmed by immunoprecipitation and by GST pulldown experiments showing the specific colocalization of KIFC3 and annexin XIIIb, a previously characterized membrane protein for apically transported vesicles (Lafont, F., S. Lecat, P. Verkade, and K. Simons. 1998. J. Cell Biol. 142:1413–1427). Furthermore, we proved that the apical transport of both influenza hemagglutinin and annexin XIIIb was partially inhibited or accelerated by overexpression of motor-domainless (dominant negative) or full-length KIFC3, respectively. Absence of cytoplasmic dynein on these annexin XIIIb–associated vesicles and distinct distribution of the two motors on the EM level verified the existence of KIFC3-driven transport in epithelial cells. PMID:11581287

Pregnancy and Radiation Exposure

MedlinePlus

... pregnant women. Ionizing radiation is the kind of electromagnetic radiation produced by x-ray machines, radioactive isotopes ( ... The reproductive risk of nonionizing radiation, which includes electromagnetic fields emitted from computers, microwave communication systems, microwave ...

Specific tritium labeling of gangliosides at the 3-position of sphingosines.

PubMed

Ghidoni, R; Sonnino, S; Masserini, M; Orlando, P; Tettamanti, G

1981-11-01

GM1 and GD1a gangliosides, treated with 2,3-dichloro-5,6-dicyano benzoquinone (DDQ) in the presence of Triton X-100 and in a toluene medium were specifically oxidized at the 3-position of sphingosine. The maximum reaction yield (65%) was obtained after 40 hours at 37 degrees C with the following molar ratio of reactants: ganglioside-Triton X-100-DDQ 1:70:125. The formation of the 3-keto derivatives of GM1 and GD1a was demonstrated by: a) the appearance of a sharp peak at 1700 cm-1 and of a broad band at 1250 cm-1 (typical of allylic ketones and of carbonyl groups, respectively) in the infra-red spectrum; b) the appearance of an absorption maximum at 230 nm, identical to that featured by 3-keto-cerebrosides, in the ultraviolet spectrum; c) the degradation of long chain bases during the process of release from gangliosides and derivatization for analysis by gas-liquid chromatography (expected for long chain bases carrying a keto group in the 3-position); and d) the quantitative transformation of 3-keto-GM1 and 3-keto-GD1a to GM1 and GD1a, respectively, upon NaBH4 reduction. Reduction of 3-keto-GM1 and 3-keto-GD1a with [3H]-NaBH4 produced 3H-labeled GM1 and GD1a. [3H]GM1 and [3H]GD1a maintained the same carbohydrate and fatty acid composition of the original GM1 and GD1a, and did not contain any saturated long chain bases. Direct proof that the label was at C-3 of long chain bases was given by reoxidation with DDQ, which completely removed the label, and by ozonolysis, after which label was retained on the oligosaccharide-containing fragment. More than 99% of incorporated radioactivity was carried by the long chain bases. The radiochemical purity of labeled gangliosides was greater than 95% and the specific radioactivity was 1.25 and 1.28 Ci/m mol for [3H]GM1 and [3H]GD1a, respectively.

Antimicrobial Activity of Galangin and Its Effects on Murein Hydrolases of Vancomycin-Intermediate Staphylococcus aureus (VISA) Strain Mu50.

PubMed

Ouyang, Jing; Sun, Fengjun; Feng, Wei; Xie, Yonghong; Ren, Lijuan; Chen, Yongchuan

2018-01-01

Backgroud: Antibiotic treatment for infections caused by vancomycin-intermediate Staphylococcus aureus (VISA) strains is challenging, and only a few effective and curative methods have been developed to combat these strains. This study aimed to investigate the antimicrobial activity of galangin against S. aureus and its effects on the murein hydrolases of VISA strain Mu50. This is the first report on these effects of galangin, and it may help to improve the treatment for VISA infections by demonstrating the effective use of galangin. Firstly, the minimum inhibitory concentration (MIC) and growth curve were used to investigate the antimicrobial activity of galangin against S. aureus. Secondly, transmission electron microscopy (TEM) was used to observe morphological changes of VISA strain Mu50. Thirdly, Triton X-100-induced autolysis and cell wall hydrolysis assays were performed to determine the activities of the murein hydrolases of Mu50. Finally, fluorescence real-time quantitative PCR was used to investigate the expression of the murein hydrolase-related Mu50 genes. The results indicated that the MIC of galangin was 32 μg/mL against ATCC25293, N315, and Mu50, and galangin could significantly suppress the bacterial growth (p < 0.05) with concentrations of 4, 8 and 16 μg/mL, compared with control group (0 μg/mL). To explore the possible reasons of bacteriostatic effects of galangin, we observed morphological changes using TEM which showed that the division of Mu50 daughter cells treated with galangin was obviously inhibited. Considering the vital role of murein hydrolases in cellular division, assays were performed, and galangin markedly decreased Triton X-100-induced autolysis and cell wall hydrolysis. Galangin also significantly inhibited the expression of the murein hydrolase genes (atl, lytM, and lytN) and their regulatory genes (cidR, cidA, and cidB). Our findings indicated that galangin can effectively inhibit murein hydrolase activity as well as the growth of VISA strain Mu50. © 2017 S. Karger AG, Basel.

Proteome analysis of the triton-insoluble erythrocyte membrane skeleton.

PubMed

Basu, Avik; Harper, Sandra; Pesciotta, Esther N; Speicher, Kaye D; Chakrabarti, Abhijit; Speicher, David W

2015-10-14

Erythrocyte shape and membrane integrity is imparted by the membrane skeleton, which can be isolated as a Triton X-100 insoluble structure that retains the biconcave shape of intact erythrocytes, indicating isolation of essentially intact membrane skeletons. These erythrocyte "Triton Skeletons" have been studied morphologically and biochemically, but unbiased proteome analysis of this substructure of the membrane has not been reported. In this study, different extraction buffers and in-depth proteome analyses were used to more fully define the protein composition of this functionally critical macromolecular complex. As expected, the major, well-characterized membrane skeleton proteins and their associated membrane anchors were recovered in good yield. But surprisingly, a substantial number of additional proteins that are not considered in erythrocyte membrane skeleton models were recovered in high yields, including myosin-9, lipid raft proteins (stomatin, flotillin1 and 2), multiple chaperone proteins (HSPs, protein disulfide isomerase and calnexin), and several other proteins. These results show that the membrane skeleton is substantially more complex than previous biochemical studies indicated, and it apparently has localized regions with unique protein compositions and functions. This comprehensive catalog of the membrane skeleton should lead to new insights into erythrocyte membrane biology and pathogenic mutations that perturb membrane stability. Biological significance Current models of erythrocyte membranes describe fairly simple homogenous structures that are incomplete. Proteome analysis of the erythrocyte membrane skeleton shows that it is quite complex and includes a substantial number of proteins whose roles and locations in the membrane are not well defined. Further elucidation of interactions involving these proteins and definition of microdomains in the membrane that contain these proteins should yield novel insights into how the membrane skeleton produces the normal biconcave erythrocyte shape and how it is perturbed in pathological conditions that destabilize the membrane. Copyright © 2015 Elsevier B.V. All rights reserved.

ICE MINERALOGY ACROSS AND INTO THE SURFACES OF PLUTO, TRITON, AND ERIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tegler, S. C.; Grundy, W. M.; Olkin, C. B.

We present three near-infrared spectra of Pluto taken with the Infrared Telescope Facility and SpeX, an optical spectrum of Triton taken with the MMT and the Red Channel Spectrograph, and previously published spectra of Pluto, Triton, and Eris. We combine these observations with a two-phase Hapke model and gain insight into the ice mineralogy on Pluto, Triton, and Eris. Specifically, we measure the methane-nitrogen mixing ratio across and into the surfaces of these icy dwarf planets. In addition, we present a laboratory experiment that demonstrates it is essential to model methane bands in spectra of icy dwarf planets with twomore » methane phases-one highly diluted by nitrogen and the other rich in methane. For Pluto, we find bulk, hemisphere-averaged, methane abundances of 9.1% {+-} 0.5%, 7.1% {+-} 0.4%, and 8.2% {+-} 0.3% for sub-Earth longitudes of 10 Degree-Sign , 125 Degree-Sign , and 257 Degree-Sign . Application of the Wilcoxon rank sum test to our measurements finds these small differences are statistically significant. For Triton, we find bulk, hemisphere-averaged, methane abundances of 5.0% {+-} 0.1% and 5.3% {+-} 0.4% for sub-Earth longitudes of 138 Degree-Sign and 314 Degree-Sign . Application of the Wilcoxon rank sum test to our measurements finds the differences are not statistically significant. For Eris, we find a bulk, hemisphere-averaged, methane abundance of 10% {+-} 2%. Pluto, Triton, and Eris do not exhibit a trend in methane-nitrogen mixing ratio with depth into their surfaces over the few centimeter range probed by these observations. This result is contrary to the expectation that since visible light penetrates deeper into a nitrogen-rich surface than the depths from which thermal emission emerges, net radiative heating at depth would drive preferential sublimation of nitrogen leading to an increase in the methane abundance with depth.« less

29 CFR 1917.1 - Scope and applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... communication. Subpart Z, § 1910.1200; (vii) Ionizing radiation. Subpart Z, § 1910.1096; (viii) Noise. Subpart G, § 1910.95; (ix) Nonionizing radiation. Subpart G, § 1910.97; (x) Respiratory protection. Subpart I...

Radiocontrast media-associated exanthema: identification of cross-reactivity and tolerability by allergologic testing.

PubMed

Seitz, Cornelia S; Pfeuffer, Petra; Raith, Petra; Bröcker, Eva-B; Trautmann, Axel

2009-10-01

All iodinated radiocontrast media (RCM) may cause hypersensitivity reactions, either immediate-type within 5-10 min of RCM injection or delayed-type, which become apparent more than 1h after RCM exposure. Delayed-type hypersensitivity to RCM may pose a problem for future radiologic investigations because due to possible immunological cross-reactivity all iodinated RCM are usually avoided. The aim of this study was not only to identify the causal RCM for the exanthema but also to demonstrate that patients may receive alternative iodinated RCM despite a history of RCM-induced allergic exanthema. We evaluated 32 patients with a history of exanthema after RCM application using standardized patch, prick and intradermal skin testing. In case of positive skin tests intravenous challenges with skin-test-negative RCM were performed to identify non-ionic monomer RCM which are tolerated. In 6 out of 32 patients skin tests strongly suggested a delayed-type non-IgE-mediated allergic hypersensitivity to the RCM iomeprol (3x), iopromide (2x), and iopamidol. In 4 patients alternative non-ionic monomer RCM (2x iosarcol, iopromide, and iomeprol) were identified by controlled challenge tests. The evaluation of patients with RCM-associated exanthema should always include appropriate skin tests ensuring that patients with a delayed-type allergic RCM-induced exanthema are not missed. Moreover, allergologic testing may identify alternative RCM of the group of non-ionic monomers, which are tolerated in future radiologic investigations.

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents

PubMed Central

Dobrivojević, Marina; Bohaček, Ivan; Erjavec, Igor; Gorup, Dunja; Gajović, Srećko

2013-01-01

Aim To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Methods Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Results Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. Conclusion MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema. PMID:23444240

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents.

PubMed

Dobrivojević, Marina; Bohaček, Ivan; Erjavec, Igor; Gorup, Dunja; Gajović, Srećko

2013-02-01

To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema.

Nutrient control for stationary phase cellulase production in Trichoderma reesei Rut C-30.

PubMed

Callow, Nicholas V; Ray, Christopher S; Kelbly, Matthew A; Ju, Lu-Kwang

2016-01-01

This work describes the use of nutrient limitations with Trichoderma reesei Rut C-30 to obtain a prolonged stationary phase cellulase production. This period of non-growth may allow for dependable cellulase production, extended fermentation periods, and the possibility to use pellet morphology for easy product separation. Phosphorus limitation was successful in halting growth and had a corresponding specific cellulase production of 5±2 FPU/g-h. Combined with the addition of Triton X-100 for fungal pellet formation and low shear conditions, a stationary phase cellulase production period in excess of 300 h was achieved, with a constant enzyme production rate of 7±1 FPU/g-h. While nitrogen limitation was also effective as a growth limiter, it, however, also prevented cellulase production. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of Leu-enkephalin and delta sleep inducing peptide (DSIP) on endogenous noradrenaline release by rat brain synaptosomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lozhanets, V.V.; Anosov, A.K.

1986-01-01

The nonapeptide delta-sleep inducing peptide (DSIP) causes specific changes in the encephalogram of recipient animals: It prolongs the phase of long-wave or delta sleep. The cellular mechanism of action of DSIP has not yet been explained. To test the hyporhesis that this peptide or its degradation product may be presynaptic regulators of catecholamine release, the action of Leu-enkephaline, DSIP, and amino acids composing DSIP on release of endogenous noradrenalin (NA) from synaptosomes during depolarization was compared. Subcellular fractions from cerebral hemisphere of noninbred male albino rats were isolated. Lactate dehydrogenase activity was determined in the suspension of synaptosomes before andmore » after addition of 0.5% Triton X-100. The results were subjected to statistical analysis, using the Wilcoxon-Mann-Whitney nonparametric test.« less

Leaching of Chalcopyrite with Thiobacillus ferrooxidans: Effect of Surfactants and Shaking

PubMed Central

Duncan, D. W.; Trussell, P. C.; Walden, C. C.

1964-01-01

The rate of leaching of chalcopyrite by Thiobacillus ferrooxidans has been greatly accelerated by using shaken flasks in place of stationary bottles or percolators. A further increase in rate and extent of leaching was obtained by the use of Tween 20, 40, 60, and 80, Triton X-100, Quaker TT 5386, and Hyamine 2389. Tween 20 was the most effective surfactant. No individual component of the Tween molecule was responsible for the improved leaching. The Tween-to-chalcopyrite ratio is more important than the Tween-to-medium ratio. The effect of the surfactants is probably due to increased contact between the mineral surface and the organism, and shaking provides the necessary oxygen. Rates and yields obtained by use of surfactants and shaking as aids to microbiological leaching approach those obtained with acidified erric sulfate leaching. PMID:14131359

Studies on sterol-ester hydrolase from Fusarium oxysporum. I. Partial purification and properties.

PubMed

Okawa, Y; Yamaguchi, T

1977-05-01

1. A search for a long chain fatty acyl sterol-ester hydrolase in microorganisms led to the isolation from soil of five strains belonging to Fusarium sp. which produced strong activity in the culture medium. 2. The cholesterol esterase from Fusarium oxysporum IGH-2 was purified about 270-fold by means of CaCl2 precipitation and Sephadex G-75 column chromatography. 3. The cholesterol esterase was activated by adekatol and Triton X-100. It was inhibited by lecithin and lysolecithin, and completely inactivated by heat treatment (60 degrees C for 30 min, at pH 7.0). 4. The optimum pH of the enzyme was found to be around 7.0. 5. Among various cholesterol esters tested, cholesterol linoleate was the most suitable substrate. 6. Cholesterol esters in serum were also hydrolyzed by this enzyme.

"Cut-off" effect of antioxidants and/or probes of variable lipophilicity in microheterogeneous media.

PubMed

Aliaga, Carolina; López de Arbina, Amaia; Rezende, Marcos Caroli

2016-09-01

The activities of two hydrophilic (ascorbic acid and Trolox) and two hydrophobic (α-tocopherol and BHT) antioxidants were measured by reaction with a series of 4-alkanoyloxyTEMPO radical probes 1 in buffered (pH 7), aqueous, micellar solutions of reduced Triton-X 100. In all cases, a cut-off effect was observed, in line with previous observations of the same effect for the partitioning of probe series 1 in this medium. These results support an interpretation of the cut-off effect in food emulsions, based on the "amphiphobic" nature of either the antioxidants or probes: competition between two molecular moieties, for the micellar hydrophobic core, tends to expose a reacting fragment differently to a more hydrophilic microenvironment, as the probe or antioxidant hydrophobicity increases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aggregation study in mixture surfactant system TX-100+SDS in heavy water solutions by SANS method

NASA Astrophysics Data System (ADS)

Rajewska, A.; Islamov, A. Kh.; Bakeeva, R. F.

2018-03-01

The mixing of amphiphiles in water may lead to the formation of mixed micelles which often present new properties with respect to the pure component solutions [1,2]. The mixture system of classic surfactants SDS (sodium dodecyl sulfate)+TX-100(p-(1,1,3,3- tetramethyl) poly(oxyethylene) (anionic + non-ionic) in heavy water solutions was investigated at temperatures 30°, 50°, 70°C for compositions 1:1, 2:1, 3:1 by the small-angle neutron scattering(SANS) method on spectrometer (‘YuMO’) at the IBR-2 pulsed neutron source at FLNP, JINR in Dubna (Russia). Measurements have covered Q range from 8x10-3 to 0.4 Å-1. From the measured dependence of the scattered intensity on the scattering angle, we derived the size, shape of micelles, aggregation number at various compositions and temperatures. The size of mixed micelle is a weak function of the mixing ratio between the two components.

Studies of the Gas Tori of Titan and Triton

NASA Technical Reports Server (NTRS)

Smyth, William H.; Marconi, M. L.

1997-01-01

A model for the spatial distribution of hydrogen in the Saturn system including a Titan source, an interior source for the rings and inner icy satellites, and a Saturn source has been applied to the best available Voyager 1 and 2 UVS Lyman-alpha observations presented by Shemansky and Hall. Although the model-data comparison is limited by the quality of the observational data, source rates for a Titan source of 3.3 - 4.8 x 10(exp 27) H atoms/s and, for the first time, source rates larger by about a factor of four for the interior source of 1.4 - 1.9 x 10(exp 27) H atoms/s were determined. Outside the immediate location of the planet, the Saturn source is only a minor contribution of hydrogen. A paper describing this research in more detail has been submitted to The Astrophysical Journal for publication and is included in the Appendix. Limited progress in the development of a model for the collisional gas tori of Triton is also discussed.

Effect of surfactants on the interaction of phenol with laccase: Molecular docking and molecular dynamics simulation studies.

PubMed

Liu, Yujie; Liu, Zhifeng; Zeng, Guangming; Chen, Ming; Jiang, Yilin; Shao, Binbin; Li, Zhigang; Liu, Yang

2018-05-22

Some surfactants can enhance the removal of phenol by laccase (Lac) in various industrial effluents. Their behavior and function in the biodegradation of phenolic wastewater have been experimentally reported by many researchers, but the underlying molecular mechanism is still unclear. Therefore, the interaction mechanisms of phenol with Lac from Trametes versicolor were investigated in the presence or absence of Triton X-100 (TX100) or rhamnolipid (RL) by molecular docking and molecular dynamics (MD) simulations. The results indicate that phenol contacts with an active site of Lac by hydrogen bonds (HBs) and van der Waals (vdW) interactions in aqueous solution for maintaining its stability. The presence of TX100 or RL results in the significant changes of enzymatic conformations. Meanwhile, the hydrophobic parts of surfactants contact with the outside surface of Lac. These changes lead to the decrease of binding energy between phenol and Lac. The migration behavior of water molecules within hydration shell is also inevitably affected. Therefore, the amphipathic TX100 or RL may influence the phenol degradation ability of Lac by modulating their interactions and water environment. This study offers molecular level of understanding on the function of surfactants in biosystem. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of surfactants and humic acids on Artemia Franciscana's embryonic phospho-metabolite profile as measured by 31P NMR.

PubMed

Deese, Rachel D; Weldeghiorghis, Thomas K; Haywood, Benjamin J; Cook, Robert L

2017-05-01

Surfactants, such as triton X-100 (Tx-100), cetylpyridinium chloride (CPC), and sodium dodecyl sulfate (SDS) are known to be toxic to Artemia Franciscana (Artemia) - an organism, frequently used to monitor the health of the aquatic environment. The phospho-metabolite profile of a living organism is often indicative of imbalances that may have been caused by environmental stressors, such as surfactants. This study utilizes in vivo 31 P NMR to monitor temporal changes in the phospho-metabolite profile of Artemia caused by Tx-100, CPC, and SDS and the ability of humic acid (HA) to mitigate the toxicity of these surfactants. It was found that, while Tx-100 does not have any effect on the phospho-metabolite profile, both CPC and SDS cause a complete retardation in growth of the phosphodiester (PDE) peak in the 31 P NMR spectrum, which is indicative of the inhibited cell replication. This growth inhibition was independently verified by the decreased guanosine triphosphate (GTP) concentration in the CPC and SDS-exposed Artemia. In addition, upon introduction of HA to the CPC and SDS-exposed Artemia, an increase of PDE peak over time is indicative of HA mitigating toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of Cell-Binding Adhesins of Leptospira interrogans

PubMed Central

Evangelista, Karen V.; Hahn, Beth; Wunder, Elsio A.; Ko, Albert I.; Haake, David A.; Coburn, Jenifer

2014-01-01

Leptospirosis is a globally distributed bacterial infectious disease caused by pathogenic members of the genus Leptospira. Infection can lead to illness ranging from mild and non-specific to severe, with jaundice, kidney and liver dysfunction, and widespread endothelial damage. The adhesion of pathogenic Leptospira species (spp.), the causative agent of leptospirosis, to host tissue components is necessary for infection and pathogenesis. While it is well-established that extracellular matrix (ECM) components play a role in the interaction of the pathogen with host molecules, we have shown that pathogenic Leptospira interrogans binds to host cells more efficiently than to ECM components. Using in vitro phage display to select for phage clones that bind to EA.hy926 endothelial cells, we identified the putative lipoproteins LIC10508 and LIC13411, and the conserved hypothetical proteins LIC12341 and LIC11574, as candidate L. interrogans sv. Copenhageni st. Fiocruz L1–130 adhesins. Recombinant LIC11574, but not its L. biflexa homologue LBF1629, exhibited dose-dependent binding to both endothelial and epithelial cells. In addition, LIC11574 and LIC13411 bind to VE-cadherin, an endothelial cell receptor for L. interrogans. Extraction of bacteria with the non-ionic detergent Triton X-114 resulted in partitioning of the candidate adhesins to the detergent fraction, a likely indication that these proteins are outer membrane localized. All candidate adhesins were recognized by sera obtained from leptospirosis patients but not by sera from healthy individuals as assessed by western blot. This work has identified bacterial adhesins that are potentially involved in L. interrogans infection of the mammalian host, and through cadherin binding, may contribute to dissemination and vascular damage. Our findings may be of value in leptospirosis control and prevention, with the bacterial adhesins potentially serving as targets for development of diagnostics, therapeutics, and vaccines. PMID:25275630

Surfactant-assisted hydrothermal crystallization of nanostructured lithium metasilicate (Li{sub 2}SiO{sub 3}) hollow spheres: II-Textural analysis and CO{sub 2}-H{sub 2}O sorption evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz-Landeros, Jose; Gomez-Yanez, Carlos; Pfeiffer, Heriberto, E-mail: pfeiffer@iim.unam.mx

In a previous work, the synthesis and structural-microstructural characterization of different nanocrystalline lithium metasilicate (Li{sub 2}SiO{sub 3}) samples were performed. Then, in this work, initially, a textural analysis was performed over the same samples. Li{sub 2}SiO{sub 3} samples prepared with a non-ionic surfactant (TRITON X-114) presented the best textural properties. Therefore, this sample was selected to evaluate its water vapor (H{sub 2}O) and carbon dioxide (CO{sub 2}) sorption properties. Sorption experiments were performed at low temperatures (30-80 deg. C) in presence of water vapor using N{sub 2} or CO{sub 2} as carrier gases. Results clearly evidenced that CO{sub 2} sorptionmore » on these materials is highly improved by H{sub 2}O vapor, and of course, textural properties enhanced the H{sub 2}O-CO{sub 2} sorption efficiency, in comparison with the solid-state reference sample. - Graphical abstract: Li{sub 2}SiO{sub 3} varied significantly its capacity of CO{sub 2} absorption as a function of the microstructural properties and by the water presence. Highlights: > We studied the CO{sub 2} absorption on different Li{sub 2}SiO{sub 3} samples in presence of H{sub 2}O vapor. > It was proved that CO{sub 2} absorption on Li{sub 2}SiO{sub 3} is controlled by different factors. > Li{sub 2}SiO{sub 3} with a porous microstructure produces a higher CO{sub 2} absorption. > H{sub 2}O vapor favors the CO{sub 2} absorption on Li{sub 2}SiO{sub 3} due to a surface hydroxylation.« less

Evaluation of viability PCR performance for assessing norovirus infectivity in fresh-cut vegetables and irrigation water.

PubMed

Randazzo, W; López-Gálvez, Francisco; Allende, A; Aznar, R; Sánchez, G

2016-07-16

Norovirus (NoV) detection in food and water is mainly carried out by quantitative RT-PCR (RT-qPCR). The inability to differentiate between infectious and inactivated viruses and the resulting overestimation of viral targets is considered a major disadvantage of RT-qPCR. Initially, conventional photoactivatable dyes (i.e. propidium monoazide, PMA and ethidium monoazide, EMA) and newly developed ones (i.e. PMAxx and PEMAX) were evaluated for the discrimination between infectious and thermally inactivated NoV genogroup I (GI) and II (GII) suspensions. Results showed that PMAxx was the best photoactivatable dye to assess NoV infectivity. This procedure was further optimized in artificially inoculated lettuce. Pretreatment with 50μM PMAxx and 0.5% Triton X-100 (Triton) for 10min reduced the signal of thermally inactivated NoV by ca. 1.8 logs for both genogroups in lettuce concentrates. Additionally, this pretreatment reduced the signal of thermally inactivated NoV GI between 1.4 and 1.9 logs in spinach and romaine and lamb's lettuces and by >2 logs for NoV GII in romaine and lamb's lettuce samples. Moreover this pretreatment was satisfactorily applied to naturally-contaminated water samples with NoV GI and GII. Based on the obtained results this pretreatment has the potential to be integrated in routine diagnoses to improve the interpretation of positive NoV results obtained by RT-qPCR. Copyright © 2016 Elsevier B.V. All rights reserved.

Analysis of a Radioisotope Thermal Rocket Engine

NASA Technical Reports Server (NTRS)

Machado-Rodriguez, Jonathan P.; Landis, Geoffrey A.

2016-01-01

The Triton Hopper is a concept for a global hopper vehicle which uses a radioisotope rocket engine and In-situ propellant acquisition to explore the surface of Neptune's moon, Triton. The current Triton Hopper concept stores heated Nitrogen in a spherical tank to be used as the propellant. The aim of the research was to investigate the benefits of storing propellant at ambient temperature and heating it through the use of a thermal block during engine operation, as opposed to storing gas at a high temperature. Lithium, Lithium Fluoride and Beryllium were considered as possible materials for the thermal block. A heat energy analysis indicated that a lithium thermal mass would provide the highest heat energy for a temperature change from 900 Celsius to -100 Celsius. A heat transfer analysis was performed for Nitrogen at -100 Celsius flowing through 1000 passages inside a 1kg lithium thermal block at a temperature of 900 Celsius. The system was analyzed as turbulent flow through a tube with constant surface temperature. The analysis indicated that the propellant reached a maximum temperature of 877 Celsius before entering the nozzle. At this exit temperature, the average specific impulse [I(sub sp)] of the engine was determined to be 157s. Previous studies for the stored heated gas concept suggest that the engine would have an average I(sub sp) of approximately 52s. Thus, the use of a thermal block concept results in a 200 percent engine performance increase. In addition, a tank sizing study was performed to determine if the concept is feasible in terms of mass requirements. The mass for a spherical carbon fiber COPV storing 35kg of nitrogen at an initial temperature of -100 Celsius and a pressure of 1000psia, was determined to be 7.2kg. The specific impulse analysis indicated that the maximum engine performance is obtained for a mass ratio of 5kg of Nitrogen per every 1kg of lithium thermal mass. Thus for 35kg of Nitrogen the total thermal mass would be 7kg. This brings the total mass of the system to 49.2.kg which is less than the 56kg landing payload capacity of the Triton Hopper. Finally, an insulation analysis using 10mm of MLI insulation indicated that a total of 22 watts of heat are lost to the environment. With the heat loss known, the power required to heat the thermal mass to 900 Celsius in 24 days was determined to be 2.15 watts. The study's results allowed us to conclude that the thermal mass concept is the better option due to the performance increase provided, the low power requirement and its compliance with the landing mass requirement of the Triton Hopper.

Purification and characterization of the enzyme cholesterol oxidase from a new isolate of Streptomyces sp.

PubMed

Praveen, Vandana; Srivastava, Akanksha; Tripathi, C K M

2011-11-01

An extracellular cholesterol oxidase (cho) enzyme was isolated from the Streptomyces parvus, a new source and purified 18-fold by ion exchange and gel filtration chromatography. Specific activity of the purified enzyme was found to be 20 U/mg with a 55 kDa molecular mass. The enzyme was stable at pH 7.2 and 50 °C. The enzyme activity was inhibited in the presence of Pb(2+), Ag(2+), Hg(2+), and Zn(2+) and enhanced in the presence of Mn(2+). The enzyme activity was inhibited by the thiol-reducing reagents (DTT, β-mercaptoethanol), suggesting that disulfide linkage is essential for the enzyme activity. The enzyme activity was found to be maximum in the presence of Triton X-100 and X-114 detergents whereas sodium dodecyl sulfate fully inactivated the enzyme. The enzyme showed moderate stability towards all organic solvents except acetone, benzene, chloroform and the activity increased in the presence of isopropanol and ethanol. The K(m) value for the oxidation of cholesterol by this enzyme was 0.02 mM.

Electrolyte compositions for lithium ion batteries

DOEpatents

Sun, Xiao-Guang; Dai, Sheng; Liao, Chen

2016-03-29

The invention is directed in a first aspect to an ionic liquid of the general formula Y.sup.+Z.sup.-, wherein Y.sup.+ is a positively-charged component of the ionic liquid and Z.sup.- is a negatively-charged component of the ionic liquid, wherein Z.sup.- is a boron-containing anion of the following formula: ##STR00001## The invention is also directed to electrolyte compositions in which the boron-containing ionic liquid Y.sup.+Z.sup.- is incorporated into a lithium ion battery electrolyte, with or without admixture with another ionic liquid Y.sup.+X.sup.- and/or non-ionic solvent and/or non-ionic solvent additive.

Electrothermal atomic absorption spectrometric determination of copper in nickel-base alloys with various chemical modifiers*1

NASA Astrophysics Data System (ADS)

Tsai, Suh-Jen Jane; Shiue, Chia-Chann; Chang, Shiow-Ing

1997-07-01

The analytical characteristics of copper in nickel-base alloys have been investigated with electrothermal atomic absorption spectrometry. Deuterium background correction was employed. The effects of various chemical modifiers on the analysis of copper were investigated. Organic modifiers which included 2-(5-bromo-2-pyridylazo)-5-(diethylamino-phenol) (Br-PADAP), ammonium citrate, 1-(2-pyridylazo)-naphthol, 4-(2-pyridylazo)resorcinol, ethylenediaminetetraacetic acid and Triton X-100 were studied. Inorganic modifiers palladium nitrate, magnesium nitrate, aluminum chloride, ammonium dihydrogen phosphate, hydrogen peroxide and potassium nitrate were also applied in this work. In addition, zirconium hydroxide and ammonium hydroxide precipitation methods have also been studied. Interference effects were effectively reduced with Br-PADAP modifier. Aqueous standards were used to construct the calibration curves. The detection limit was 1.9 pg. Standard reference materials of nickel-base alloys were used to evaluate the accuracy of the proposed method. The copper contents determined with the proposed method agreed closely with the certified values of the reference materials. The recoveries were within the range 90-100% with relative standard deviation of less than 10%. Good precision was obtained.

Influence of MWCNT/surfactant dispersions on the mechanical properties of Portland cement pastes

NASA Astrophysics Data System (ADS)

Rodríguez, B.; Quintero, J. H.; Arias, Y. P.; Mendoza-Reales, O. A.; Ochoa-Botero, J. C.; Toledo-Filho, R. D.

2017-12-01

This work studies the reinforcing effect of Multi Walled Carbon Nanotubes (MWCNT) on cement pastes. A 0.35% solid concentration of MWCNT in powder was dispersed in deionized water with sodium dodecyl sulfate (cationic surfactant), cetylpyridinium chloride (anionic surfactant) and triton X-100 (amphoteric surfactant) using an ultrasonic tip processor. Three concentrations of each surfactant (1mM, 10mM and 100mM) were tested, and all samples were sonicated until an adequate dispersion degree was obtained. Cement pastes with additions of carbon nanotubes of 0.15% by mass of cement were produced in two steps; first the dispersions of MWCNT were combined with the mixing water using an ultrasonic tip processor to guarantee homogeneity, and then cement was added and mixed until a homogeneous paste was obtained. Direct tensile strength, apparent density and open porosity of the pastes were measured after 7 days of curing. It was found that the MWCNT/surfactants dispersions decrease the mechanical properties of the cement based matrix due to an increased porosity caused by the presence of surfactants.

Flotability and flotation separation of polymer materials modulated by wetting agents.

PubMed

Wang, Hui; Wang, Chong-qing; Fu, Jian-gang; Gu, Guo-hua

2014-02-01

The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS)>tannic acid (TA)>methylcellulose (MC)>triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biocompatible Adhesives

DTIC Science & Technology

1991-03-01

gram of —> Triton X-405 (70%) and 0.5 gram sodium lauryl sulfate . After a nitrogen -3- /- „, y-iu/iouitj Cod*s Avail and/oh ’t , • Special...period of several hours and d) using a redox system comprising of additional persulfate and a reducing agent such as sodium bisulfite or sodium

Anisotropic etching of silicon in solutions containing tensioactive compounds

NASA Astrophysics Data System (ADS)

Zubel, Irena

2016-12-01

The results of investigations concerning anisotropic etching in 3M KOH and 25% TMAH solutions modified by tensioactive compounds such as alcohols, diols and a typical surfactant Triton X100 have been compared. Etching anisotropy was assessed on the basis of etch rates ratio V(110)/V(100). It was stated that the relation between surface tension of the solutions and etch rates of particular planes depend not only on the kind of surfactant but also on the kind of etching solution (KOH, TMAH). It points out an important role of TMA+ ions in the etching process, probably in the process of forming an adsorption layer, consisting of the molecules of tensioactive compounds on Si surface, which decides about etch rate. We have observed that this phenomenon occurs only at high concentration of TMA+ ions (25% TMAH). Reduction of TMAH concentration changes the properties of surfactant containing TMAH solutions. From all investigated solutions, the solutions that assured developing of (110) plane inclined at the angle of 45° to (100) substrate were selected. Such planes can be used as micromirrors in MOEMS structures. The solutions provide the etch rate ratio V(110)/V(100)<0.7, thus they were selected from hydroxide solutions containing surfactants. A simple way for etch rate anisotropy V(110)/V(100) assessment based on microscopic images etched structures has been proposed.

Collisional Cascades Following Triton's Capture

NASA Astrophysics Data System (ADS)

Cuk, Matija; Hamilton, Douglas P.; Stewart-Mukhopadhyay, Sarah T.

2017-10-01

Neptune's moon Triton is widely thought to have been captured from heliocentric orbit, most likely through binary dissociation (Agnor and Hamilton, 2006). Triton's original eccentric orbit must have been subsequently circularized by satellite tides (Goldreich et al. 1989). Cuk and Gladman (2005) found that Kozai oscillations make early tidal evolution inefficient, and have proposed that collisions between Triton and debris from pre-existing satellites was the dominant mechanism of shrinking Triton's large post-capture orbit. However, Cuk and Hamilton (DPS 2016), using numerical simulations and results of Stewart and Leinhardt (2012), have found that collisions between regular satellites are unlikely to be destructive, while collisions between prograde moons and Triton are certainly erosive if not catastrophic. An obvious outcome would be pre-existing moon material gradually grinding down Triton and making it reaccrete in the local Laplace plane, in conflict with Triton's large current inclination. We propose that the crucial ingredient for understanding the early evolution of the Neptunian system are the collisions between the moons and the prograde and retrograde debris originating from the pre-existing moons and Triton. In particular, we expect early erosive impact(s) on Triton to generate debris that will, in subsequent collisions, disrupt the regular satellites. If the retrograde material were to dominate at some planetocentric distances, the end result may be a large cloud or disk of retrograde debris that would be accreted by Triton, shrinking Triton's orbit. Some of the prograde debris could survive in a compact disk interior to Triton's pericenter, eventually forming the inner moons of Neptune. We will present results of numerical modeling of these complex dynamical processes at the meeting.

In vitro enzymatic reduction kinetics of mineral oxides by membrane fractions from Shewanella oneidensis MR-1

NASA Astrophysics Data System (ADS)

Ruebush, Shane S.; Icopini, Gary A.; Brantley, Susan L.; Tien, Ming

2006-01-01

This study documents the first example of in vitro solid-phase mineral oxide reduction by enzyme-containing membrane fractions. Previous in vitro studies have only reported the reduction of aqueous ions. Total membrane (TM) fractions from iron-grown cultures of Shewanella oneidensis MR-1 were isolated and shown to catalyze the reduction of goethite, hematite, birnessite, and ramsdellite/pyrolusite using formate. In contrast, nicotinamide adenine dinucleotide (NADH) and succinate cannot function as electron donors. The significant implications of observations related to this cell-free system are: (i) both iron and manganese mineral oxides are reduced by the TM fraction, but aqueous U(VI) is not; (ii) TM fractions from anaerobically grown, but not aerobically grown, cells can reduce the mineral oxides; (iii) electron shuttles and iron chelators are not needed for this in vitro reduction, documenting conclusively that reduction can occur by direct contact with the mineral oxide; (iv) electron shuttles and EDTA stimulate the in vitro Fe(III) reduction, documenting that exogenous molecules can enhance rates of enzymatic mineral reduction; and (v) multiple membrane components are involved in solid-phase oxide reduction. The membrane fractions, consisting of liposomes of cytoplasmic and outer membrane segments, contain at least 100 proteins including the enzyme that oxidizes formate, formate dehydrogenase. Mineral oxide reduction was inhibited by the addition of detergent Triton X-100, which solubilizes membranes and their associated proteins, consistent with the involvement of multiple electron carriers that are disrupted by detergent addition. In contrast, formate dehydrogenase activity was not inhibited by Triton X-100. The addition of anthraquinone-2,6-disulfonate (AQDS) and menaquinone-4 was unable to restore activity; however, menadione (MD) restored 33% of the activity. The addition of AQDS and MD to reactions without added detergent increased the rate of goethite reduction. The Michaelis-Menten Km values of 71 ± 22 m 2/L for hematite and 50 ± 16 m 2/L for goethite were calculated as a function of surface area of the two insoluble minerals. Vmax was determined to be 123 ± 14 and 156 ± 13 nmol Fe(II)/min/mg of TM protein for hematite and goethite, respectively. These values are consistent with in vivo rates of reduction reported in the literature. These observations are consistent with our conclusion that the enzymatic reduction of mineral oxides is an effective probe that will allow elucidation of molecular chemistry of the membrane-mineral interface where electron transfer occurs.

Extended Fluorescent Resonant Energy Transfer in DNA Constructs

NASA Astrophysics Data System (ADS)

Oh, Taeseok

This study investigates the use of surfactants and metal cations for the enhancement of long range fluorescent resonant energy transfer (FRET) and the antenna effect in DNA structures with multiple fluorescent dyes. Double-stranded (ds) DNA structures were formed by hybridization of 21mer DNA oligonucleotides with different arrangements of three fluorescent TAMRA donor dyes with two different complementary 21mer oligonucleotides with one fluorescent TexasRed acceptor dye. In such DNA structures, hydrophobic interactions between the fluorescent dyes in close proximity produces dimerization which along with other quenching mechanisms leads to significant reduction of fluorescent emission properties. Addition of the surfactants Triton X-100, cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) along with sodium cations (Na+) and divalent magnesium cations (Mg 2+) were tested for their ability to reduce quenching of the fluorescent dyes and improve overall fluorescent emission, the long range FRET and the antenna effect properties. When the neutral (uncharged) surfactant Triton X-100 was added to the FRET ds-DNA hybrid structures with three TAMRA donors and one TexasRed acceptor, dye dimerization and emission quenching remained unaffected. However, for the positively charged CTAB surfactant at concentrations of 100 uM or higher, the neutralization of the negatively charged ds-DNA backbone by the cationic surfactant micelles was found to reduce TAMRA dye dimerization and emission quenching and improve TexasRed quantum yield, resulting in much higher FRET efficiencies and an enhanced antenna effect. This improvement is likely due to the CTAB molecules covering or sheathing the fluorescent donor and acceptor dyes which breaks up the dimerized dye complexes and prevents further quenching from interactions with water molecules and guanine bases in the DNA structure. While the negatively charged SDS surfactant alone was not able to reduce dimerization and emission quenching due to repulsive forces between DNA and SDS micelles, the addition of cations such as sodium ions (Na+) and divalent magnesium ions (Mg2+) did lead to a significant reduction in the dimerization and emission quenching resulting in much higher FRET efficiency and an enhanced antenna effect. It appears that when the repulsive electrostatic forces are screened by the cations (Mg2+ in particular), the SDS micelles can approach the FRET ds-DNA structures thereby sheathing or insulating the TAMRA and TexasRed dyes. Overall, the study provides a viable strategy for using combinations of surfactants and cations to reduce adverse fluorescent dye and other quenching mechanisms and improve the overall long distance FRET efficiency and the antenna effect in DNA structures with multi-donor and single acceptor fluorescent dye groups.

Physicochemical Properties of Biosurfactant Produced by Pseudomonas fluorescens Grown on Whey Tofu

NASA Astrophysics Data System (ADS)

Suryanti, V.; Handayani, D. S.; Marliyana, S. D.; Suratmi, S.

2017-02-01

The research aims to examine the physicochemical properties of biosurfactant produced by Pseudomonas fluorescens. Biosurfactant was produced in whey tofu media containing 8 g/L nutrient broth and 5 g/L NaCl which was fermented for 2 days at room temperature. Biosurfactant was identified as rhamnolipids which had critical micelle concentration (CMC) value of 638 mg/L and surface tension of 54 mN/m. The biosurfactant had water in oil (w/o) emulsion type. The biosurfactant was able to decrease the interfacial tension more than 40% for emulsion of water with hexane, pentane, benzene, lubricants or kerosene. The stable emulsions were reached up to 30 days with the E24 value of about 50% when paraffin, toluene, lubricants or palm oil was used as an immiscible compound. Commercial surfactants, such as Triton X-100 and Tween-80 were investigated to compare their emulsification activities and emulsion stabilities with the produced biosurfactant.

Reaction Kinetics of Phenolic Antioxidants toward Photoinduced Pyranine Free Radicals in Biological Models.

PubMed

Aspée, Alexis; Aliaga, Christian; Maretti, Luca; Zúñiga-Núñez, Daniel; Godoy, Jessica; Pino, Eduardo; Cárdenas-Jirón, Gloria; Lopez-Alarcon, Camilo; Scaiano, Juan C; Alarcon, Emilio I

2017-07-06

8-Hydroxy-1,3,6-pyrenetrisulfonic acid (pyranine, PyOH) free radicals were induced by laser excitation at visible wavelengths (470 nm). The photochemical process involves photoelectron ejection from PyO- to produce PyO• and PyO•- with maxima absorption at 450 and 510 nm, respectively. The kinetic rate constants for phenolic antioxidants with PyO•, determined by nanosecond time-resolved spectroscopy, were largely reliant on the ionic strength depending on the antioxidant phenol/phenolate dissociation constant. Further, the apparent rate constant measured in the presence of Triton X100 micelles was influenced by the antioxidant partition between the micelle and the dispersant aqueous media but limited by its exit rates from the micelle. Similarly, the rate reaction between ascorbic acid and PyO• was markedly affected by the presence of human serum albumin responding to the dynamic of the ascorbic acid binding to the protein.

Extraction methods and test techniques for detection of vegetable proteins in meat products. I. Qualitative detection of soya derivatives.

PubMed

Hyslop, N S

1976-06-01

Extracts of 3 soya bean preparations, used commercially in certain countries to replace part of the meat in popular meat products, were made by treatment with (i) sodium dodecyl sulphate, (ii) Triton-X100 or (iii) n-Butanol. Similar extracts were made from beef and pork. All extracts were examined by electrophoretic and immunological techniques. Stained polyacrylamide gels revealed distinctive protein bands after electrophoresis. The migration rates of corresponding bands differed between beef and pork extracts. However, the migration rates of vegetable bands revealed certain similarities, but differed very greatly from those of animal origin. Characteristic fast-migrating S-bands were distinguishable only in extracts of vegetable protein. Immunodiffusion tests, using antisera produced in rabbits against each extract, revealed varying degrees of similarity between extracts of vegetable origin, but the antisera were specific for either vegetable or animal protein.

Lidocaine effect on flotillin-2 distribution in detergent-resistant membranes of equine jejunal smooth muscle in vitro.

PubMed

Tappenbeck, Karen; Schmidt, Sonja; Feige, Karsten; Naim, Hassan Y; Huber, Korinna

2014-05-01

Lidocaine is the most commonly chosen prokinetic for treating postoperative ileus in horses, a motility disorder associated with ischaemia-reperfusion injury of intestinal tissues. Despite the frequent use of lidocaine, the mechanism underlying its prokinetic effects is still unclear. Previous studies suggested that lidocaine altered cell membrane characteristics of smooth muscle cells. Therefore, the present study aimed to elucidate effects of lidocaine administration on characteristics of detergent-resistant membranes in equine jejunal smooth muscle. Lidocaine administration caused significant redistribution of flotillin-2, a protein marker of detergent-resistant membranes, in fractions of sucrose-density-gradients obtained from ischaemia-reperfusion injured smooth muscle solubilised with Triton X-100. It was concluded that lidocaine induced disruption of detergent-resistant membranes which might affect ion channel activity and therefore enhance smooth muscle contractility. Copyright © 2014 Elsevier Ltd. All rights reserved.

Application of Biosurfactants Produced by Pseudomonas putida using Crude Palm Oil (CPO) as Substrate for Crude Oil Recovery using Batch Method

NASA Astrophysics Data System (ADS)

Suryanti, V.; Handayani, D. S.; Masykur, A.; Septyaningsih, I.

2018-03-01

The application of biosurfactants which have been produced by Pseudomonas putida in nutrient broth medium supplemented with NaCl and crude palm oil (CPO) for oil recovery has been evaluated. The crude and purified biosurfactants have been examined for oil recovery from a laboratory oil-contaminated sand in agitated flask (batch method). Two synthetic surfactants and water as control was also performed for oil recovery as comparisons. Using batch method, the results showed that removing ability of crude oil from the oil-contaminated sand by purified and crude biosurfactants were 79.40±3.10 and 46.84±2.23 %, respectively. On other hand, the recoveries obtained with the SDS, Triton X-100 and water were 94.33±0.47, 74.84±7.39 and 34.42±1.21%respectively.

Phosphatidylglycerol synthesis in castor bean endosperm. [Ricinus communis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, T.S. Jr.

1974-01-01

The synthesis of phosphatidylglycerol in castor bean (Ricinus communis var. Hale) endosperm tissue was found to be located in both the endoplasmic reticulum and mitochondrial fractions separated on sucrose density gradients. The enzyme of both fractions attained maximum activity at 5 mM Mn/sup 2 +/, 0.075 percent Triton X-100, and pH 7.3. The addition of dithiothreitol produced little effect, but sulfhydryl inhibitors reduced activity in both systems. Cytidine diphosphate-diglyceride exhibited an apparent Michaelis constant for the endoplasmic reticulum enzyme of 2.8 ..mu..M and for the mitochondrial enzyme of 2.0 ..mu..M; the maximum reaction rate was achieved at about 20 ..mu..M.more » For the second substrate, glycerol-phosphate, the apparent Michaelis constant for both fractions was about 50 ..mu..M and maximum velocity was reached at 400 ..mu..M. The specific activity of the mitochondrial enzyme was generally twice that of the endoplasmic reticulum.« less

Giant unilamellar vesicles containing Rhodamine 6G as a marker for immunoassay of bovine serum albumin and lipocalin-2.

PubMed

Sakamoto, Misato; Shoji, Atsushi; Sugawara, Masao

2016-07-15

Functionalized giant unilamellar vesicles (GUVs) containing a fluorescence dye Rhodamine 6G is proposed as a marker in sandwich-type immunoassay for bovine serum albumin (BSA) and lipocalin-2 (LCN2). The GUVs were prepared by the electroformation method and functionalized with anti-BSA antibody and anti-LCN2 antibody, respectively. The purification of antibody-modified GUVs was achieved by conventional centrifugation and a washing step in a flow system. To antigen on an antibody slip, antibody-modified GUVs were added as a marker and incubated. After wash-out of excess reagents and lysis of the bound GUVs with Triton X-100, the fluorescence image was captured. The fluorometric immunoassays for BSA and LCN2 exhibited lower detection limits of 4 and 80 fg ml(-)(1), respectively. Copyright © 2016 Elsevier Inc. All rights reserved.

Extraction methods and test techniques for detection of vegetable proteins in meat products. I. Qualitative detection of soya derivatives.

PubMed Central

Hyslop, N. S.

1976-01-01

Extracts of 3 soya bean preparations, used commercially in certain countries to replace part of the meat in popular meat products, were made by treatment with (i) sodium dodecyl sulphate, (ii) Triton-X100 or (iii) n-Butanol. Similar extracts were made from beef and pork. All extracts were examined by electrophoretic and immunological techniques. Stained polyacrylamide gels revealed distinctive protein bands after electrophoresis. The migration rates of corresponding bands differed between beef and pork extracts. However, the migration rates of vegetable bands revealed certain similarities, but differed very greatly from those of animal origin. Characteristic fast-migrating S-bands were distinguishable only in extracts of vegetable protein. Immunodiffusion tests, using antisera produced in rabbits against each extract, revealed varying degrees of similarity between extracts of vegetable origin, but the antisera were specific for either vegetable or animal protein. Images Plate 1 Plate 2 PMID:819572

Physical Properties of Human Whole Salivary Mucin:A Dynamic Light Scattering Study

NASA Astrophysics Data System (ADS)

Mahajan, Manish; Kumar, Vijay; Saraswat, Mayank; Yadav, Savita; Shukla, N. K.; Singh, T. P.

2008-04-01

Human salivary mucin, a primary mucous membrane coating glycoprotein forms the first line of defense against adverse environments, attributed to the complex formation between mucin subunits and non mucin species. Aim of the study was to emphasize the effect of pH, denaturants (guanidinum hydrochloride, urea) and detergents (CHAPS, TRITON X -100, SDS on human whole salivary mucin. Hydrodynamic size distribution was measured using DLS. It was observed that aggregation was due to increase in hydrophobic interactions, believed to be accomplished by unfolding of the protein core. Whereas, the detergents which solubilize the proteins by decreasing hydrophobicity lead to disaggregation of mucin into smaller fragments. Mucin subjected to tobacco extract and upon subsequent addition of nicotine was found to have a disaggregating effect on it, suggesting nicotine may be one of the factors responsible for the disaggregating effect of tobacco on mucin, an important carcinogenetic mechanism.

Characterization of the Membrane-Bound Succinic Dehydrogenase of Micrococcus lysodeikticus

PubMed Central

Pollock, Jerry J.; Linder, Regina; Salton, Milton R. J.

1971-01-01

The occurrence of succinic dehydrogenase [succinic:(acceptor) oxidoreductase, EC 1.3.99.1] in membrane fractions of Micrococcus lysodeikticus was investigated. The enzyme could be purified 10-fold, by deoxycholate treatment. Butanol extraction of membranes yielded an active fraction, nonsedimentable at 130,000 × g for 2 hr and altered in its phospholipid content relative to membranes. The activity of the enzyme in particulate preparations was decreased in the presence of competitive inhibitors and by compounds known to react with iron, sulfhydryl groups, and flavine. In this respect, the bacterial succinic dehydrogenase is similar to the enzyme derived from yeast and mammalian sources. In certain membrane fractions, Ca2+ and Mg2+ exhibited inhibitory effects whereas Triton X-100 caused activation. The enzyme could also be activated by substrate. In the phenazine reductase assay, incomplete reduction of electron acceptor was observed upon addition of divalent cations and iron binding agents. Images PMID:4327510

Immunological properties of Micrococcus lysodeikticus membranes.

PubMed

Fukui, Y; Nachbar, M S; Salton, M R

1971-01-01

Membranes of Micrococcus lysodeikticus possess antigens which are distinct from other cellular components such as cytoplasm, ribosomes, and cell walls. Only a few (two to three) components are found when dissociated membranes are examined by immunodiffusion and immunoelectrophoresis techniques. Membranes treated with 0.3% sodium dodecyl sulfate, 0.3% Triton X-100, trypsin, phospholipase A or C, or by sonic oscillation at pH 9.0, all showed the same pattern (three major bands) when examined against membrane antisera by immunoelectrophoresis. Immunological analysis of fractions isolated by sucrose gradient centrifugation or by polyacrylamide gel electrophoresis suggests that individual components cross-react. Antibodies to adenosine triphosphatase (EC 3.6.1.3) and fast-moving component are not removed by absorption with protoplasts. Removal of antibody to one of the membrane antigens by protoplast absorption indicated a surface location. Glutaraldehyde fixation of protoplasts resulted in the loss of membrane antigens detectable by immunodiffusion.

Inability to detect transferrin receptors on P. falciparum parasitized red cells.

PubMed

Pollack, S; Schnelle, V

1988-01-01

The mechanism by which P. falciparum takes up iron from transferrin has been explored. Binding of 125I labelled transferrin to parasitized red cells at 37 degrees C is two-fold greater than to control cells; at 0 degrees C there is no significant difference. The binding is non-specific as judged from the following: it is not saturable; it is not limited to transferrin as lactoferrin (which has iron binding domains) and bovine serum albumin (which does not) also bind in excess to parasitized red cells. A transferrin receptor complex could not be demonstrated when parasitized red cells, to which 125I transferrin was bound, were solubilized in Triton X100. Previous observation showed that uptake of transferrin iron by parasitized red cells is not accompanied by equimolar uptake of transferrin protein. We therefore suggest that nonspecifically bound transferrin is endocytosed, that the protein is degraded and the iron selectively retained.

A kinetic method for the determination of thiourea by its catalytic effect in micellar media

NASA Astrophysics Data System (ADS)

Abbasi, Shahryar; Khani, Hossein; Gholivand, Mohammad Bagher; Naghipour, Ali; Farmany, Abbas; Abbasi, Freshteh

2009-03-01

A highly sensitive, selective and simple kinetic method was developed for the determination of trace levels of thiourea based on its catalytic effect on the oxidation of janus green in phosphoric acid media and presence of Triton X-100 surfactant without any separation and pre-concentration steps. The reaction was monitored spectrophotometrically by tracing the formation of the green-colored oxidized product of janus green at 617 nm within 15 min of mixing the reagents. The effect of some factors on the reaction speed was investigated. Following the recommended procedure, thiourea could be determined with linear calibration graph in 0.03-10.00 μg/ml range. The detection limit of the proposed method is 0.02 μg/ml. Most of foreign species do not interfere with the determination. The high sensitivity and selectivity of the proposed method allowed its successful application to fruit juice and industrial waste water.

Cell-based dose responses from open-well microchambers.

PubMed

Hamon, Morgan; Jambovane, Sachin; Bradley, Lauren; Khademhosseini, Ali; Hong, Jong Wook

2013-05-21

Cell-based assays play a critical role in discovery of new drugs and facilitating research in cancer, immunology, and stem cells. Conventionally, they are performed in Petri dishes, tubes, or well plates, using milliliters of reagents and thousands of cells to obtain one data point. Here, we are introducing a new platform to realize cell-based assay capable of increased throughput and greater sensitivity with a limited number of cells. We integrated an array of open-well microchambers into a gradient generation system. Consequently, cell-based dose responses were examined with a single device. We measured IC50 values of three cytotoxic chemicals, Triton X-100, H2O2, and cadmium chloride, as model compounds. The present system is highly suitable for the discovery of new drugs and studying the effect of chemicals on cell viability or mortality with limited samples and cells.

Evidence for a plasma-membrane-bound nitrate reductase involved in nitrate uptake of Chlorella sorokiniana

NASA Technical Reports Server (NTRS)

Tischner, R.; Ward, M. R.; Huffaker, R. C.

1989-01-01

Anti-nitrate-reductase (NR) immunoglobulin-G (IgG) fragments inhibited nitrate uptake into Chlorella cells but had no affect on nitrate uptake. Intact anti-NR serum and preimmune IgG fragments had no affect on nitrate uptake. Membrane-associated NR was detected in plasma-membrane (PM) fractions isolated by aqueous two-phase partitioning. The PM-associated NR was not removed by sonicating PM vesicles in 500 mM NaCl and 1 mM ethylenediaminetetraacetic acid and represented up to 0.8% of the total Chlorella NR activity. The PM NR was solubilized by Triton X-100 and inactivated by Chlorella NR antiserum. Plasma-membrane NR was present in ammonium-grown Chlorella cells that completely lacked soluble NR activity. The subunit sizes of the PM and soluble NRs were 60 and 95 kDa, respectively, as determined by sodium-dodecyl-sulfate electrophoresis and western blotting.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, D.W.; Laties, G.G.

Potato mitochondria (Solanum tuberosum var. Russet Burbank), which readily phosphorylate ADP in oxidative phosphorylation, show low levels of ATPase activity which is stimulated neither by Mg/sup 2 +/, 2,4-dinitrophenol, incubation with respiratory substrates, nor disruption by sonication or treatment with Triton X-100, individually or in concert. Treatment of disrupted potato mitochondria with trypsin stimulates Mg/sup 2 +/-dependent, oligomycin-sensitive ATPase activity 10- to 15-fold, suggesting the presence of an ATPase inhibitor protein. Trypsin-induced ATPase activity was unaffected by uncoupler. Oligomycin-sensitive ATPase activity decreases as exposure to trypsin is increased. Incubation at alkaline pH or heating at 60/sup 0/C for 2 minutesmore » also activates ATPase of sonicated potato mitochondria. Disruption of cauliflower (Brassica oleracea), red sweet potato (Ipomoea batatas), and carrot (Daucus carota) mitochondria increases ATPase activity, which is further enhanced by treatment with trypsin. The significance of the tight association of the inhibitor protein and ATPase in potato mitochondria is not clear.« less

Surfactant and nonlinear drop dynamics in microgravity

NASA Astrophysics Data System (ADS)

Jankovsky, Joseph Charles

2000-11-01

Large amplitude drop dynamics in microgravity were conducted during the second United States Microgravity Laboratory mission carried onboard the Space Shuttle Columbia (20 October-5 November 1995). Centimeter- sized drops were statically deformed by acoustic radiation pressure and released to oscillate freely about a spherical equilibrium. Initial aspect ratios of up to 2.0 were achieved. Experiments using pure water and varying aqueous concentrations of Triton-X 100 and bovine serum albumin (BSA) were performed. The axisymmetric drop shape oscillations were fit using the degenerate spherical shape modes. The frequency and decay values of the fundamental quadrupole and fourth order shape mode were analyzed. Several large amplitude nonlinear oscillation dynamics were observed. Shape entrainment of the higher modes by the fundamental quadrupole mode occurred. Amplitude- dependent effects were observed. The nonlinear frequency shift, where the oscillation frequency is found to decrease with larger amplitudes, was largely unaffected by the presence of surfactants. The percentage of time spent in the prolate shape over one oscillation cycle was found to increase with oscillation amplitude. This prolate shape bias was also unaffected by the addition of surfactants. These amplitude-dependent effects indicate that the nonlinearities are a function of the bulk properties and not the surface properties. BSA was found to greatly enhance the surface viscoelastic properties by increasing the total damping of the oscillation, while Triton had only a small influence on damping. The surface concentration of BSA was found to be diffusion-controlled over the time of the experiments, while the Triton diffusion rate was very rapid. Using the experimental frequency and decay values, the suface viscoelastic properties of surface dilatational viscosity ( ks ) and surface shear viscosity ( ms ) were found for varying surfactant concentrations using the transcendental equation of Lu & Apfel (1991) and Tian et al. (1997). Values for Triton for concentrations of 0.017 to 2 CMC range from 0.01 to 0.05 surface poise (sp) for ks . For BSA, the fitting of the experimental data was highly sensitive to ms over a wide range of ks . Setting ks = 1 sp for 1 CMC drops ms , was found to increase from 0.07 to 0.28 sp linearly with the square root of time, indicating that surface shear viscosity is proportional to the surface concentration in the diffusion-controlled regime. The same time dependence was found for 2 CMC drops. However, the fitted shear viscosity was nearly half that of the 1 CMC concentration over the same time frame.

Influenza Vaccine Manufacturing: Effect of Inactivation, Splitting and Site of Manufacturing. Comparison of Influenza Vaccine Production Processes

PubMed Central

Kon, Theone C.; Onu, Adrian; Berbecila, Laurentiu; Lupulescu, Emilia; Ghiorgisor, Alina; Kersten, Gideon F.; Cui, Yi-Qing; Amorij, Jean-Pierre; Van der Pol, Leo

2016-01-01

The aim of this study was to evaluate the impact of different inactivation and splitting procedures on influenza vaccine product composition, stability and recovery to support transfer of process technology. Four split and two whole inactivated virus (WIV) influenza vaccine bulks were produced and compared with respect to release criteria, stability of the bulk and haemagglutinin recovery. One clarified harvest of influenza H3N2 A/Uruguay virus prepared on 25.000 fertilized eggs was divided equally over six downstream processes. The main unit operation for purification was sucrose gradient zonal ultracentrifugation. The inactivation of the virus was performed with either formaldehyde in phosphate buffer or with beta-propiolactone in citrate buffer. For splitting of the viral products in presence of Tween®, either Triton™ X-100 or di-ethyl-ether was used. Removal of ether was established by centrifugation and evaporation, whereas removal of Triton-X100 was performed by hydrophobic interaction chromatography. All products were sterile filtered and subjected to a 5 months real time stability study. In all processes, major product losses were measured after sterile filtration; with larger losses for split virus than for WIV. The beta-propiolactone inactivation on average resulted in higher recoveries compared to processes using formaldehyde inactivation. Especially ether split formaldehyde product showed low recovery and least stability over a period of five months. PMID:26959983

Effect of bentonite modification on hardness and mechanical properties of natural rubber nanocomposites

NASA Astrophysics Data System (ADS)

Santiago, Denise Ester O.; Pajarito, Bryan B.; Mangaccat, Winna Faye F.; Tigue, Maelyn Rose M.; Tipton, Monica T.

2016-05-01

The effect of sodium activation, ion-exchange with tertiary amine salt, surface treatment with non-ionic surfactant, and wet grinding of bentonite on hardness and mechanical properties of natural rubber nanocomposites (NRN) was studied using full factorial design of experiment. Results of X-ray diffraction (XRD) show increase in basal spacing d of bentonite due to modification, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirm the organic modification of bentonite. Analysis of variance (ANOVA) shows that the main effect of surface treatment increases the hardness and decreases the tensile modulus of the NRN. The surface treatment and wet grinding of bentonite decrease the tensile stresses at 100, 200 and 300% strain of NRN. Sodium activation and ion-exchange negatively affect the compressive properties, while surface treatment significantly improves the compressive properties of NRN.

The thermal structure of Triton's atmosphere - Pre-Voyager models

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.; Pollack, James B.; Zent, Aaron P.; Cruikshank, Dale P.; Courtin, Regis

1989-01-01

Spectral data from earth observations have indicated the presence of N2 and CH4 on Triton. This paper outlines the use of the 1-D radiative-convective model developed for Titan to calculate the current pressure of N2 and CH4 on Triton. The production of haze material is obtained by scaling down from the Titan value. Results and predictions for the Voyager Triton encounter are as follows: A N2-CH4 atmosphere on Triton is thermodynamically self consistent and would have a surface pressure of approximately 50 millibar; due to the chemically produced haze, Triton has a hot atmosphere with a temperature of approximately 130 K; Triton's troposphere is a region of saturation of the major constituent of the atmosphere, N2.

Physical and radiological properties of radiochromic gel as of its composition

NASA Astrophysics Data System (ADS)

Lee, Sang Hoon; Kim, Juree; Shim, Su Jung; Chang, Kyung Hwan; Lim, Sangwook; Huh, Hyun Do; Shin, Dong Oh; Cho, Sam Ju

2014-04-01

In the research, we evaluated the use of leuco crystal violet (LCV) gel as a dosimeter for therapeutic radiation by investigating its optical characteristics at various component concentrations. We also investigated the aging effect of the LCV gel at different beam energies, doserates, and dosing times to evaluate the LCV's applicability to radiation therapy. We confirmed that the optimal optical wavelength of the LCV gel dosimeter was 600 nm. The dose sensitivity increased with increasing concentration of LCV; however, the optimal concentration was 1 mM LCV because the transparency of the gel dosimeter is important for use in optical CT scanners. However, the dose sensitivity decreased with increasing concentration of trichloroacetic acid (TAA). Moreover, the transparency of LCV rapidly decreased because of the generation of a white precipitate at TAA concentrations below 25 mM. Thus, an optimal TAA concentration of 30 mM was used in this study. Triton X-100 (8 mM) was identified as the optimal reagent for determining the optimum gel transparency and dose sensitivity. Thus, we present an LCV gel dosimeter composed of 4% gelatin by mass, 1 mM LCV, 30 mM TAA, and 8-mM Triton X-100 for use with an optical CT scanner. We showed good dose linearity up to 30 Gy. There was a little doserate dependency at a beam energy of 6 MV while the doserate dependence was more than 4.2% at a beam energy of 10 MV. To evaluate the energy dependence of the LCV gel dosimeter, we irradiated it at 20 Gy by using 6 MV and 10 MV beams. At the high doserate, the difference in the dose energy dependence was relatively small at approximately 1%, but the difference increased to 4.6% at the low doserate. With respect to the radiation absorbance at a photon energy of 6 MV, the absorbance at an electron energy of 6 MeV decreased by 5.4%, and the absorbances at 9, 12, and 15 MeV increased by 3, 18.7, and 12.2%, respectively. Furthermore, the aging effect was larger in the low-dose group then in the high-dose group. Moreover, we observed that the absorbance between 24 and 48 h after irradiation increased by approximately 5% at 5 Gy. For gel groups tested at high doses, the aging effect was reduced by approximately 1%.

Real-time three-dimensional imaging of epidermal splitting and removal by high-definition optical coherence tomography.

PubMed

Boone, Marc; Draye, Jean Pierre; Verween, Gunther; Pirnay, Jean-Paul; Verbeken, Gilbert; De Vos, Daniel; Rose, Thomas; Jennes, Serge; Jemec, Gregor B E; Del Marmol, Véronique

2014-10-01

While real-time 3-D evaluation of human skin constructs is needed, only 2-D non-invasive imaging techniques are available. The aim of this paper is to evaluate the potential of high-definition optical coherence tomography (HD-OCT) for real-time 3-D assessment of the epidermal splitting and decellularization. Human skin samples were incubated with four different agents: Dispase II, NaCl 1 M, sodium dodecyl sulphate (SDS) and Triton X-100. Epidermal splitting, dermo-epidermal junction, acellularity and 3-D architecture of dermal matrices were evaluated by High-definition optical coherence tomography before and after incubation. Real-time 3-D HD-OCT assessment was compared with 2-D en face assessment by reflectance confocal microscopy (RCM). (Immuno) histopathology was used as control. HD-OCT imaging allowed real-time 3-D visualization of the impact of selected agents on epidermal splitting, dermo-epidermal junction, dermal architecture, vascular spaces and cellularity. RCM has a better resolution (1 μm) than HD-OCT (3 μm), permitting differentiation of different collagen fibres, but HD-OCT imaging has deeper penetration (570 μm) than RCM imaging (200 μm). Dispase II and NaCl treatments were found to be equally efficient in the removal of the epidermis from human split-thickness skin allografts. However, a different epidermal splitting level at the dermo-epidermal junction could be observed and confirmed by immunolabelling of collagen type IV and type VII. Epidermal splitting occurred at the level of the lamina densa with dispase II and above the lamina densa (in the lamina lucida) with NaCl. The 3-D architecture of dermal papillae and dermis was more affected by Dispase II on HD-OCT which corresponded with histopathologic (orcein staining) fragmentation of elastic fibres. With SDS treatment, the epidermal removal was incomplete as remnants of the epidermal basal cell layer remained attached to the basement membrane on the dermis. With Triton X-100 treatment, the epidermis was not removed. In conclusion, HD-OCT imaging permits real-time 3-D visualization of the impact of selected agents on human skin allografts. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Detail of Triton Surface

NASA Image and Video Library

1999-05-08

This color photo of Neptune large satellite Triton was obtained on Aug. 24 1989. In reality, there is no part of Triton that would appear blue to the eye. The bright southern hemisphere of Triton, which fills most of this frame, is generally pink.

TnBP⁄Triton X-45 Treatment of Plasma for Transfusion Efficiently Inactivates Hepatitis C Virus

PubMed Central

Chou, Ming-Li; Burnouf, Thierry; Chang, Shun-Pang; Hung, Ting-Chun; Lin, Chun-Ching; Richardson, Christopher D.; Lin, Liang-Tzung

2015-01-01

Risk of transmission of hepatitis C virus (HCV) by clinical plasma remains high in countries with a high prevalence of hepatitis C, justifying the implementation of viral inactivation treatments. In this study, we assessed the extent of inactivation of HCV during minipool solvent/detergent (SD; 1% TnBP / 1% Triton X-45) treatment of human plasma. Luciferase-tagged infectious cell culture-derived HCV (HCVcc) particles were used to spike human plasma prior to treatment by SD at 31 ± 0.5°C for 30 min. Samples were taken before and after SD treatment and filtered on a Sep-Pak Plus C18 cartridge to remove the SD agents. Risk of cytotoxicity was assessed by XTT cell viability assay. Viral infectivity was analyzed based on the luciferase signals, 50% tissue culture infectious dose viral titer, and immunofluorescence staining for HCV NS5A protein. Total protein, cholesterol, and triglyceride contents were determined before and after SD treatment and C18 cartridge filtration. Binding analysis, using patient-derived HCV clinical isolates, was also examined to validate the efficacy of the inactivation by SD. SD treatment effectively inactivated HCVcc within 30 min, as demonstrated by the baseline level of reporter signals, total loss of viral infectivity, and absence of viral protein NS5A. SD specifically targeted HCV particles to render them inactive, with essentially no effect on plasma protein content and hemostatic function. More importantly, the efficacy of the SD inactivation method was confirmed against various genotypes of patient-derived HCV clinical isolates and against HCVcc infection of primary human hepatocytes. Therefore, treatment by 1% TnBP / 1% Triton X-45 at 31°C is highly efficient to inactivate HCV in plasma for transfusion, showing its capacity to enhance the safety of therapeutic plasma products. We propose that the methodology used here to study HCV infectivity can be valuable in the validation of viral inactivation and removal processes of human plasma-derived products. PMID:25658612

Establishing Structure Property Relationship in Drug Partitioning into and Release from Niosomes: Physical Chemistry Insights with Anti-Inflammatory Drugs.

PubMed

Dasgupta, Moumita; Kishore, Nand

2017-09-28

Understanding the physical chemistry underlying interactions of drugs with delivery formulations is extremely important in devising effective drug delivery systems. The partitioning and release kinetics of diclofenac sodium and naproxen from Brij 30 and Triton X-100 niosomal formulations have been addressed based on structural characterization, partitioning energetics, and release kinetics, thus establishing a relationship between structures and observed properties. Both the drugs partition in nonpolar regions of TX-100 niosomes via stacking of aromatic rings. The combined effects of interactions of the drugs with polar head groups and the rigidity of the niosome vesicles determine entry and partitioning of drugs into niosomes. The observed slower rate of release of the drugs from the drug encapsulated niosomes of TX-100 than those of Brij 30, suggest stable complexation of drugs in the nonpolar interior of the former. No release of drugs from the niosomes was observed until 24 h even upon varying pH conditions without SDS. However, SDS in drug loaded niosomes led to release of drugs in as early as 6 h. The sustained pattern of in vitro release kinetics of the drugs thus observed from our niosomal preparations suggest these vesicular systems to be promising for pharamaceutical applications as potential drug delivery vehicles.

Proteomic comparison of two fractions derived from the transsynaptic scaffold.

PubMed

Phillips, Greg R; Florens, Laurence; Tanaka, Hidekazu; Khaing, Zin Z; Fidler, Lazar; Yates, John R; Colman, David R

2005-09-15

A fraction derived from presynaptic specializations (presynaptic particle fraction; PPF) can be separated from postsynaptic densities (PSD) by adjusting the pH of Triton X-100 (TX-100) extraction of isolated transsynaptic scaffolds. Solubilization of the PPF corresponds to disruption of the presynaptic specialization. We show that the PPF is insoluble to repeated TX-100 extraction at pH 6.0 but becomes soluble in detergent at pH 8.0. By immunolocalization, we find that the major proteins of the PPF, clathrin and dynamin, are concentrated in the presynaptic compartment. By using multidimensional protein identification technology, we compared the protein compositions of the PPF and the PSD fraction. We identified a total of 341 proteins, 50 of which were uniquely found in the PPF, 231 in the PSD fraction, and 60 in both fractions. Comparison of the two fractions revealed a relatively low proportion of actin and associated proteins and a high proportion of vesicle or intracellular compartment proteins in the PPF. We conclude that the PPF consists of presynaptic proteins not connected to the actin-based synaptic framework; its insolubility in pH 6 and solubility in pH 8 buffered detergent suggests that clathrin might be an anchorage scaffold for many proteins in the PPF. (c) 2005 Wiley-Liss, Inc.

On the origin of Triton and Pluto

NASA Technical Reports Server (NTRS)

Mckinnon, W. B.

1984-01-01

Lyttleton's (1936) hypothesis that Triton and Pluto originated as adjacent prograde satellites of Neptune is evaluated, and it is shown that with the presently accepted masses of Triton and Pluto-Charon, the momentum and energy exchange required to set Triton on a retrograde orbit is impossible. The Pluto-Charon system could not have acquired its present angular momentum state during an ejection event unless a physical collision was involved, which is quite unlikely. The simplest hypothesis is that Triton and Pluto are independent representatives of large outer solar system planetesimals. Triton is simply captured, with spectacular consequences that include runaway melting of interior ices and release to the surface of clathrated CH4, CO, and N2. Condensed remnants of this protoatmosphere could account for features in Triton's unique spectrum.

On the Origin of Triton and Pluto

NASA Technical Reports Server (NTRS)

Mckinnon, W. B.

1985-01-01

Lyttleton's (1936) hypothesis that Triton and Pluto originated as adjacent prograde satellites of Neptune is evaluated, and it is shown that with the presently accepted masses of Triton and Pluto-Charon, the momentum and energy exchange required to sell Triton on a retrograde orbit is impossible. The Pluto-Charon system could not have acquired its present angular momentum state during an ejection event unless a physical collision was involved, which is quite unlikely. The simplest hypothesis is that Triton and Pluto are independent representatives of large outer solar system planetesimals. Triton is simply captured, with spectacular consequences that include runaway melting of interior ices and release to the surface of clathrated CH4, CO, and N2. Condensed remnants of this protoatmosphere could account for features in Triton's unique spectrum.

Identification of a major polypeptide of the nuclear pore complex

PubMed Central

1982-01-01

The nuclear pore complex is a prominent structural component of the nuclear envelope that appears to regulate nucleoplasmic molecular movement. Up to now, none of its polypeptides have been defined. To identify possible pore complex proteins, we fractionated rat liver nuclear envelopes and microsomal membranes with strong protein perturbants into peripheral and intrinsic membrane proteins, and compared these fractions on SDS gels. From this analysis, we identified a prominent 190-kilodalton intrinsic membrane polypeptide that occurs specifically in nuclear envelopes. Lectin binding studies indicate that this polypeptide (gp 190) is the major nuclear envelope glycoprotein. Upon treatment of nuclear envelopes with Triton X-100, gp 190 remains associated with a protein substructure of the nuclear envelope consisting of pore complexes and nuclear lamina. We prepared monospecific antibodies to gp 190 for immunocytochemical localization. Immunofluorescence staining of tissue culture cells suggests that gp 190 occurs exclusively in the nucleus during interphase. This polypeptide becomes dispersed throughout the cell in mitotic prophase when the nuclear envelope is disassembled, and subsequently returns to the nuclear surfaces during telophase when the nuclear envelope is reconstructed. Immunoferritin labeling of Triton-treated rat liver nuclei demonstrates that gp 190 occurs exclusively in the nuclear pore complex, in the regions of the cytoplasmic (and possibly nucleoplasmic) pore complex annuli. A polypeptide that cross-reacts with gp 190 is present in diverse vertebrate species, as shown by antibody labeling of nitrocellulose SDS gel transfers. On the basis of its biochemical characteristics, we suggest that gp 190 may be involved in anchoring the pore complex to nuclear envelope membranes. PMID:7153248

Evaluation of an ODS column modified with zwitterionic/nonionic mixed surfactants and its application to direct injection determination of inorganic anions.

PubMed

Hasegawa, Takuya; Umemura, Tomonari; Koide, Akira; Chiba, Koichi; Ueki, Yuji; Tsunoda, Kin-ichi; Haraguchi, Hiroki

2005-08-01

An octadecylsilica (ODS) column modified with zwitterionic/nonionic mixed surfactants was evaluated for the direct injection determination of inorganic anions in biological fluids by ion chromatography. A zwitterionic surfactant (sulfobetaine-type) and a nonionic surfactant (polyoxyethylene-type) were used for a stationary-phase modification. When aqueous electrolyte solutions with concentrations of sub-mM to several mM were used as a mobile phase, the zwitterionic surfactant coated on the ODS surface exhibited unique separation selectivity for ionic species, while the nonionic surfactant coated on the ODS might have formed a hydrophilic network over the ODS surface and restricted matrix proteins from adsorbing on the stationary phase. Consequently, the mixed surfactant-modified column system allowed an efficient ion chromatographic separation of inorganic anions as well as a size-exclusive removal of column-fouling proteins. This separation system was applied to the direct injection determination of UV-absorbing anions in human saliva. The detection limits for nitrite, nitrate, iodide and thiocyanate were 3.1, 2.7, 4.5 and 25 microM, respectively, with UV detection at 210 nm (injection volume; 20 microl), and their relative standard deviations for 5 replicate measurements of saliva samples spiked with 100 microM each of those anions were 1.4, 0.9, 2.2 and 5.5%, respectively.

30 CFR 50.20-6 - Criteria-MSHA Form 7000-1, Section C.

Code of Federal Regulations, 2011 CFR

2011-07-01

... daughters, non-medical, non-therapeutic X-rays, radium); effects of nonionizing radiation (welding flash, ultra-violet rays, micro-waves, sunburn). (vi) Code 26—Disorders Associated with Repeated Trauma...). Examples: Poisoning by lead, mercury, cadmium, arsenic, or other metals, poisoning by carbon monoxide...

Measurement of the force and torque produced in the calcium response of reactivated rat sperm flagella.

PubMed

Moritz, M J; Schmitz, K A; Lindemann, C B

2001-05-01

Rat sperm that are demembranated with Triton X-100 and reactivated with Mg-ATP show a strong mechanical response to the presence of free calcium ion. At pCa < 4, the midpiece region of the flagellum develops a strong and sustained curvature that gives the cell the overall appearance of a fishhook [Lindemann and Goltz, 1988: Cell Motil. Cytoskeleton 10:420-431]. In the present study, the force and torque that maintain the calcium-induced hook have been examined quantitatively. In addition, full-length and shortened flagella were manipulated to evaluate the plasticity of the hooks and determined the critical length necessary for maintaining the curvature. The hooks were found to be highly resilient, returning to their original configuration (>95%) after being straightened and released. The results from manipulating the shortened flagella suggest that the force holding the hook in the curved configuration is generated in the basal 60 microm of the flagellum. The force required to straighten the calcium-induced hooks was measured with force-calibrated glass microprobes, and the bending torque was calculated from the measured force. The force and torque required to straighten the flagellum were found to be proportional to the change in curvature of the hooked region of the flagellum, suggesting an elastic-like behavior. The average torque to open the hooks to a straight position was 2.6 (+/-1.4) x 10(-7) dyne x cm (2.6 x 10(-14) N x m) and the apparent stiffness was 4.3 (+/-1.3) x 10(-10) dyne x cm(2) (4.3 x 10(-19) N x m(2)). The stiffness of the hook was determined to be approximately one quarter the rigor stiffness of a rat sperm flagellum measured under comparable conditions.

Triton's surface properties - A preliminary analysis from ground-based, Voyager photopolarimeter subsystem, and laboratory measurements

NASA Technical Reports Server (NTRS)

Buratti, B. J.; Lane, A. L.; Gibson, J.; Burrows, H.; Nelson, R. M.; Bliss, D.; Smythe, W.; Garkanian, V.; Wallis, B.

1991-01-01

The surface properties of Triton were investigated using data from the ground-based and Voyager photopolarimeter subsystem (PPS) observations of Triton's phase curve. The results indicate that Triton has a high single-scattering albedo (0.96 +/-0.01 at 0.75 micron) and an unusually compacted surface, possibly similar to that of Europa. Results also suggest that Triton's single-particle phase function and the macroscopically rough character of its surface are similar to those of most other icy satellites.

The first UV spectrum of Triton - IUE observations from 2600 to 3200 A

NASA Technical Reports Server (NTRS)

Stern, S. Alan; Skinner, T. E.; Brosch, N.; Van Santvoort, J.; Trafton, L. M.

1989-01-01

The results of the first observations of Triton's spectrum below 3300 A are reported. Triton's 2700 A geometric albedo is found to be 0.28 + or - 0.04. The albedo increases monotonically from 2600 to 3200 A, with a slope of 0.13 + or - 0.03 per 1000 A. This positive slope is qualitatively similar to, but shallower than, Triton's visible albedo slope and argues against a strong Rayleigh scattering signature. Triton's integrated flux is found to be 1.5 times Pluto's, indicating Triton to be either more reflective in the UV, or bigger, or both. The redness of Triton's visible and UV colors argues against an extremely bright surface and for a larger radius than Pluto's. A lower limit on the radius of 1240 + or - 90 km is derived. The spectrum observed by IUE is consistent with either an icy surface or a suspended aerosol layer which preferentially absorbs UV light.

Effect of bentonite modification on hardness and mechanical properties of natural rubber nanocomposites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santiago, Denise Ester O.; Department of Chemical Engineering, University of the Philippines, Los Baños, College, Laguna 4031 Philippines; Pajarito, Bryan B.

The effect of sodium activation, ion-exchange with tertiary amine salt, surface treatment with non-ionic surfactant, and wet grinding of bentonite on hardness and mechanical properties of natural rubber nanocomposites (NRN) was studied using full factorial design of experiment. Results of X-ray diffraction (XRD) show increase in basal spacing d of bentonite due to modification, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirm the organic modification of bentonite. Analysis of variance (ANOVA) shows that the main effect of surface treatment increases the hardness and decreases the tensile modulus of the NRN. The surface treatment and wet grinding of bentonitemore » decrease the tensile stresses at 100, 200 and 300% strain of NRN. Sodium activation and ion-exchange negatively affect the compressive properties, while surface treatment significantly improves the compressive properties of NRN.« less

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method

PubMed Central

Gavrilović, Tamara V.; Jovanović, Dragana J.; Lojpur, Vesna; Dramićanin, Miroslav D.

2014-01-01

Synthesis of Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each particle comprises a single crystallite. Eu3+-doped GdVO4 nanoparticles emit red light through downconversion upon UV excitation. Er3+/Yb3+-doped GdVO4 nanoparticles exhibit several functions; apart from the downconversion of UV radiation into visible green light, they act as upconvertors, transforming near-infrared excitation (980 nm) into visible green light. The ratio of green emissions from 2H11/2 → 2I15/2 and 4S3/2 → 4I15/2 transitions is temperature dependent and can be used for nanoscale temperature sensing with near-infrared excitation. The relative sensor sensitivity is 1.11%K−1, which is among the highest sensitivities recorded for upconversion-luminescence-based thermometers. PMID:24572638

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method

NASA Astrophysics Data System (ADS)

Gavrilović, Tamara V.; Jovanović, Dragana J.; Lojpur, Vesna; Dramićanin, Miroslav D.

2014-02-01

Synthesis of Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each particle comprises a single crystallite. Eu3+-doped GdVO4 nanoparticles emit red light through downconversion upon UV excitation. Er3+/Yb3+-doped GdVO4 nanoparticles exhibit several functions; apart from the downconversion of UV radiation into visible green light, they act as upconvertors, transforming near-infrared excitation (980 nm) into visible green light. The ratio of green emissions from 2H11/2 --> 2I15/2 and 4S3/2 --> 4I15/2 transitions is temperature dependent and can be used for nanoscale temperature sensing with near-infrared excitation. The relative sensor sensitivity is 1.11%K-1, which is among the highest sensitivities recorded for upconversion-luminescence-based thermometers.

Titania nano-coated quartz wool for the photocatalytic mineralisation of emerging organic contaminants.

PubMed

Saracino, M; Pretali, L; Capobianco, M L; Emmi, S S; Navacchia, M L; Bezzi, F; Mingazzini, C; Burresi, E; Zanelli, A

2018-01-01

Many emerging contaminants pass through conventional wastewater treatment plants, contaminating surface and drinking water. The implementation of advanced oxidation processes in existing plants for emerging contaminant remediation is one of the challenges for the enhancement of water quality in the industrialised countries. This paper reports on the production of a TiO 2 nano-layer on quartz wool in a relevant amount, its characterisation by X-ray diffraction and scanning electron microscopy, and its use as a photocatalyst under ultraviolet radiation for the simultaneous mineralisation of five emerging organic contaminants (benzophenone-3, benzophenone-4, carbamazepine, diclofenac, and triton X-100) dissolved in deionised water and tap water. This treatment was compared with direct ultraviolet photolysis and with photocatalytic degradation on commercial TiO 2 micropearls. The disappearance of every pollutant was measured by high performance liquid chromatography and mineralisation was assessed by the determination of total organic carbon. After 4 hours of treatment with the TiO 2 nano-coated quartz wool, the mineralisation exceeds 90% in deionised water and is about 70% in tap water. This catalyst was reused for seven cycles without significant efficiency loss.

Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in W/O Microemulsion

NASA Astrophysics Data System (ADS)

Deshpande, Aniruddha S.; Khomane, Ramdas B.; Vaidya, Bhalchandra K.; Joshi, Renuka M.; Harle, Arti S.; Kulkarni, Bhaskar D.

2008-06-01

Sulfur nanoparticles were synthesized from hazardous H2S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe3+ malic acid chelate (0.05 M aqueous solution) was studied in w/o microemulsion containing cyclohexane, Triton X-100 and n-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of α-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm) and narrow particle size distribution (in range of 5 15 nm) as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%). Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi) than that of colloidal sulfur.