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.

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.

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.

Dissociation, aggregation of sesame alpha-globulin in nonionic detergent solution.

PubMed

Lakshmi, T S; Nandi, P K

1978-10-01

Nonionic detergents Triton X-100 and Brij 36T induce dissociation and aggregation of the protein sesame alpha-globulin above the critical micelle concentrations (cmc) of the detergents. Spectrophotometric titration in Triton shows no change in the pKInt value of the tyrosyl groups at 1x10-3 M detergent where both dissociation and aggregation of the protein are observed. Fluorescence measurement does not indicate any change in the environment of the tryptophan groups of the protein in Brij. Viscosity measurements show no major conformational change of the protein in the detergent solution. Binding measurements suggest that perhaps micelles of the detergent predominantly bind to the protein. The detergent micelles preferentially bind to the exposed hydrophobic surfaces of the protein subunits. The association of the protein detergent complex through electrostatic interaction is probably responsible for the formation of the aggregates.

Effect of nonionic compound emulsifiers Tween80 and Span80 on the properties of microencapsulated phase change materials.

PubMed

Zhan, Shiping; Zhou, Zhiyi; Wang, Weijing; Zhao, Qicheng; Hou, Weimin

2014-01-01

In this article, the nonionic compound emulsifiers Tween80 and Span80 were used to prepare microcapsules containing phase change materials (microPCMs) with melamine-formaldehyde (MF) shells by in situ polymerization method. The effects of compound emulsifiers Tween80 and Span80 on the structure, morphologies and properties of microPCMs containing paraffin were studied. SEM morphological investigation suggests that a complex of Tween80 and Span80 as emulsifiers are optimal for the fabrication of microPCMs in this study compared to Tween60 or OP-10. The diameter distributions of microPCMs synthesized with different amounts of compound emulsifiers are uniform, whereas compound emulsifiers' amount affect the mean diameter of microPCMs decreasing from 5.34 to 3.05 µm. These microPCMs with the core/shell weight ratio 3/1 have smoother surface and a higher core content of 68.7% than other core/shell ratio. Anti-osmosis measurements indicate that microPCMs have good compactness and stable performance compared to those synthesized by one type of emulsifier.

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.

Phospholipid analysis and fractional reconstitution of the ice nucleation protein activity purified from Escherichia coli overexpressing the inaZ gene of Pseudomonas syringae.

PubMed

Palaiomylitou, M A; Kalimanis, A; Koukkou, A I; Drainas, C; Anastassopoulos, E; Panopoulos, N J; Ekateriniadou, L V; Kyriakidis, D A

1998-08-01

Ice nucleation protein was partially purified from the membrane fraction of E. coli carrying inaZ from Pseudomonas syringae. The ice nucleation protein was totally localized in the bacterial envelope and was extracted by either salt (0.25 M NH4Cl) or the nonionic detergent Tween 20. The extracted protein was partially purified by sequential passage through DEAE-52 cellulose and Sephacryl-S400 columns. The activity of the purified protein was lost after treatment with phospholipase C, and its activity was subsequently restored by addition of the naturally occurring lipid phosphatidylethanolamine. These results suggest that ice nucleation proteins have a requirement for lipids that reconstitute a physiological hydrophobic environment similar to the one existing in vivo, to attain and maintain a structure that enables ice catalysis. Copyright 1998 Academic Press.

Solubilization of flurbiprofen within non-ionic Tween 20 surfactant micelles: a 19F and 1H NMR study.

PubMed

Saveyn, Pieter; Cocquyt, Ellen; Zhu, Wuxin; Sinnaeve, Davy; Haustraete, Katrien; Martins, José C; Van der Meeren, Paul

2009-07-14

The solubilization of the poorly water soluble anti-inflammatory drug flurbiprofen in non-ionic Tween 20 surfactant micellar solutions was studied by both (19)F and (1)H NMR spectroscopy in an acidic environment. These non-destructive techniques allowed us to investigate the effect of temperature cycling in situ. Using (19)F NMR, an increased solubilisation capacity was observed as the temperature increased. This effect became more pronounced above the cloud point, which was reduced by more than 30 degrees C in the presence of an excess of flurbiprofen. Upon clouding, peak splitting was observed in the (19)F spectrum, which indicates that two pools of solubilised flurbiprofen exist that are in slow exchange on the NMR frequency timescale. The clouding and solubilization processes were found to be reversible, albeit with slow kinetics. Based on chemical shift differences of both Tween 20 and flurbiprofen, as well as NOESY experiments, the flurbiprofen was found to be accumulated within the palisade layer of the Tween 20 micelles.

Membrane protein stability can be compromised by detergent interactions with the extramembranous soluble domains

PubMed Central

Yang, Zhengrong; Wang, Chi; Zhou, Qingxian; An, Jianli; Hildebrandt, Ellen; Aleksandrov, Luba A; Kappes, John C; DeLucas, Lawrence J; Riordan, John R; Urbatsch, Ina L; Hunt, John F; Brouillette, Christie G

2014-01-01

Detergent interaction with extramembranous soluble domains (ESDs) is not commonly considered an important determinant of integral membrane protein (IMP) behavior during purification and crystallization, even though ESDs contribute to the stability of many IMPs. Here we demonstrate that some generally nondenaturing detergents critically destabilize a model ESD, the first nucleotide-binding domain (NBD1) from the human cystic fibrosis transmembrane conductance regulator (CFTR), a model IMP. Notably, the detergents show equivalent trends in their influence on the stability of isolated NBD1 and full-length CFTR. We used differential scanning calorimetry (DSC) and circular dichroism (CD) spectroscopy to monitor changes in NBD1 stability and secondary structure, respectively, during titration with a series of detergents. Their effective harshness in these assays mirrors that widely accepted for their interaction with IMPs, i.e., anionic > zwitterionic > nonionic. It is noteworthy that including lipids or nonionic detergents is shown to mitigate detergent harshness, as will limiting contact time. We infer three thermodynamic mechanisms from the observed thermal destabilization by monomer or micelle: (i) binding to the unfolded state with no change in the native structure (all detergent classes); (ii) native state binding that alters thermodynamic properties and perhaps conformation (nonionic detergents); and (iii) detergent binding that directly leads to denaturation of the native state (anionic and zwitterionic). These results demonstrate that the accepted model for the harshness of detergents applies to their interaction with an ESD. It is concluded that destabilization of extramembranous soluble domains by specific detergents will influence the stability of some IMPs during purification. PMID:24652590

Optimized formation of detergent micelles of beta-carotene and retinal production using recombinant human beta,beta-carotene 15,15'-monooxygenase.

PubMed

Kim, Nam-Hee; Kim, Yeong-Su; Kim, Hye-Jung; Oh, Deok-Kun

2008-01-01

The formation of beta-carotene detergent micelles and their conversion into retinal by recombinant human beta,beta-carotene 15,15'-monooxygenase was optimized under aqueous conditions. Toluene was the most hydrophobic among the organic solvents tested; thus, it was used to dissolve beta-carotene, which is a hydrophobic compound. Tween 80 was selected as the detergent because it supported the highest level of retinal production among all of the detergents tested. The maximum production of retinal was achieved in detergent micelles containing 200 mg/L of beta-carotene and 2.4% (w/v) Tween 80. Under these conditions, the recombinant enzyme produced 97 mg/L of retinal after 16 h with a conversion yield of 48.5% (w/w). The amount of retinal produced, which is the highest ever reported, is a result of the ability of our system to dissolve large amounts of beta-carotene.

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®

Detergent solubilization of the EGF receptor from A431 cells

NASA Technical Reports Server (NTRS)

Dayanidhi, R.; Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

1993-01-01

Functional reconstitution of purified preparations of human epidermal growth factor receptor (EGFR) requires dissociation of the protein from its plasma membrane lipid environment. Solubilization of membrane proteins in this manner requires the use of detergents, which are known to disrupt plasma membrane lipid/protein interactions. We have investigated the ability of three nonionic detergents to solubilize the human EGFR selectively, and have also analyzed the effect of these various treatments on the intrinsic tyrosyl kinase activity of the receptor. The nonionic detergent known as n-octyl glucoside (n-octyl beta-D-glucopyranoside) was found to give the best combination of selectivity, yield, and maintenance of enzymatic activity of the human EGFR.

Active Detergent-solubilized H+,K+-ATPase Is a Monomer*

PubMed Central

Dach, Ingrid; Olesen, Claus; Signor, Luca; Nissen, Poul; le Maire, Marc; Møller, Jesper V.; Ebel, Christine

2012-01-01

The H+,K+-ATPase pumps protons or hydronium ions and is responsible for the acidification of the gastric fluid. It is made up of an α-catalytic and a β-glycosylated subunit. The relation between cation translocation and the organization of the protein in the membrane are not well understood. We describe here how pure and functionally active pig gastric H+,K+-ATPase with an apparent Stokes radius of 6.3 nm can be obtained after solubilization with the non-ionic detergent C12E8, followed by exchange of C12E8 with Tween 20 on a Superose 6 column. Mass spectroscopy indicates that the β-subunit bears an excess mass of 9 kDa attributable to glycosylation. From chemical analysis, there are 0.25 g of phospholipids and around 0.024 g of cholesterol bound per g of protein. Analytical ultracentrifugation shows one main complex, sedimenting at s20,w = 7.2 ± 0.1 S, together with minor amounts of irreversibly aggregated material. From these data, a buoyant molecular mass is calculated, corresponding to an H+,K+-ATPase α,β-protomer of 147.3 kDa. Complementary sedimentation velocity with deuterated water gives a picture of an α,β-protomer with 0.9–1.4 g/g of bound detergent and lipids and a reasonable frictional ratio of 1.5, corresponding to a Stokes radius of 7.1 nm. An α2,β2 dimer is rejected by the data. Light scattering coupled to gel filtration confirms the monomeric state of solubilized H+,K+-ATPase. Thus, α,β H+,K+-ATPase is active at least in detergent and may plausibly function as a monomer, as has been established for other P-type ATPases, Ca2+-ATPase and Na+,K+-ATPase. PMID:23055529

The role of various surfactants on the release of salbutamol from suppositories.

PubMed

Hanaee, J; Javadzadeh, Y; Taftachi, S; Farid, D; Nokhodchi, A

2004-11-01

Salbutamol is a selective beta(2)-adrenoreceptor agonist with different pharmacological effects. In this research because of the simplicity of suppository application in elderly and its higher plasma concentration than tablets as well as its particular indication in premature labour, salbutamol suppositories were prepared. The suppositories were formulated containing 10 mg of the drug and Witepsol H15, the oleaginous soluble base using melting method. To optimize the release rate of drug, different surfactants namely, sodium lauryl sulphate (SLS) as an ionic surfactant and Tween 80 as well as Arlacel 60 as non-ionic surfactants with different HLBs were chosen. The effect of surfactant concentration on the release rate of salbutamol from suppositories were also investigated. All prepared formulations fulfilled the specifications set down in British Pharmacopoeia. The results showed that Tween 80 (2%w/w) and SLS (0.75%w/w) caused an increase in dissolution rate of salbutamol from suppositories. As anionic surfactants, such as SLS, cause greater damage on mucosa than non-ionic surfactant, such as Tween 80, this study recommended that Tween 80 could be added in suppository formulation in order to increase the dissolution rate of salbutamol. It was also shown that the release rate of salbutamol altered linearly with the amount of Tween 80 in suppository formulations.

Formulation, characterization and pharmacokinetics of Morin hydrate niosomes prepared from various non-ionic surfactants.

PubMed

Waddad, Ayman Y; Abbad, Sarra; Yu, Fan; Munyendo, Were L L; Wang, Jing; Lv, Huixia; Zhou, Jianping

2013-11-18

Morin hydrate (MH), a bioflavonoid with antioxidant and anticancer activity as well as the ability to improve the bioavailability of other drugs on their concurrent use. Three differently optimized niosomal formulations using three different non-ionic surfactants (Span 60, Span 80 and Tween 60) were achieved by (L9 (3(4))) Taguchi orthogonal array (TOA). The analysis of TOA revealed that Tween 60 Niosomes had the highest entrapment efficiency (93.4%) compared to other optimized Niosomal formulations (71-79%). In terms of MH remaining %, Tween 60 Niosomes were found to be the most stable (89%) at 4 °C over one month compared to Span 60 (56%) and Span 80 (57%) Niosomes. The release pattern in all Niosomal formulations was found to follow the Weibull model and Tween 60 Niosomes had the highest release rate. The molecular modeling simulation explained the binding of MH to the human serum albumin (HSA) by hydrogen bonds during the in vitro release process. As for the bioavailability, the AUC0-8 showed 1.3-2.7 fold increase compared to the MH solution. Ex vivo images of the excised organs showed that MH could accumulate in brain which indicates that MH-Tween 60 Niosomes might be a possible candidate to deliver hydrophobic drugs and overcome the blood-brain barrier (BBB) penetration. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of synthetic detergents on the swelling and the ATPase of mitochondria isolated from rat liver.

PubMed

WITTER, R F; MINK, W

1958-01-25

A study was made of the effects of various types of detergents on the swelling of isolated mitochondria and on mitochondrial ATPases which are activated by Mg or DNP respectively. The rate of swelling was measured in the Beckman spectrophotometer by following the decrease in turbidity of dilute suspensions of these organelles. It was found that non-ionic detergents containing a nonyl phenoxy side chain or anionic detergents caused swelling of the mitochondria and activation of Mg-ATPase. On the other hand, cationic detergents promoted the clumping of mitochondria and did not activate Mg-ATPase. DNP-ATPase was inhibited by all of the detergents tested. It would appear from these observations that the inhibition of DNP-ATPase is not related to a gross change in the morphology of the organelles; in contrast, the activation of Mg-ATPase definitely is correlated with swelling of the isolated mitochondria. These data also suggest that the ionic detergents combine with charged sites on the protein moiety of the lipoprotein in the mitochondrial surface, whereas the non-ionic detergents form inclusion compounds with the lipide moiety, thereby altering the mitochondrial structure and permeability.

Submicrometer Emitter ESI Tips for Native Mass Spectrometry of Membrane Proteins in Ionic and Nonionic Detergents

NASA Astrophysics Data System (ADS)

Susa, Anna C.; Lippens, Jennifer L.; Xia, Zijie; Loo, Joseph A.; Campuzano, Iain D. G.; Williams, Evan R.

2018-01-01

Native mass spectrometry (native-MS) of membrane proteins typically requires a detergent screening protocol, protein solubilization in the preferred detergent, followed by protein liberation from the micelle by collisional activation. Here, submicrometer nano-ESI emitter tips are used for native-MS of membrane proteins solubilized in both nonionic and ionic detergent solutions. With the submicrometer nano-ESI emitter tips, resolved charge-state distributions of membrane protein ions are obtained from a 150 mM NaCl, 25 mM Tris-HCl with 1.1% octyl glucoside solution. The relative abundances of NaCl and detergent cluster ions at high m / z are significantly reduced with the submicrometer emitters compared with larger nano-ESI emitters that are commonly used. This technique is beneficial for significantly decreasing the abundances (by two to three orders of magnitude compared with the larger tip size: 1.6 μm) of detergent cluster ions formed from aqueous ammonium acetate solutions containing detergents that can overlap with the membrane protein ion signal. Resolved charge-state distributions of membrane protein ions from aqueous ammonium acetate solutions containing ionic detergents were obtained with the submicrometer nano-ESI emitters; this is the first report of native-MS of membrane proteins solubilized by ionic detergents. [Figure not available: see fulltext.

Submicrometer Emitter ESI Tips for Native Mass Spectrometry of Membrane Proteins in Ionic and Nonionic Detergents.

PubMed

Susa, Anna C; Lippens, Jennifer L; Xia, Zijie; Loo, Joseph A; Campuzano, Iain D G; Williams, Evan R

2018-01-01

Native mass spectrometry (native-MS) of membrane proteins typically requires a detergent screening protocol, protein solubilization in the preferred detergent, followed by protein liberation from the micelle by collisional activation. Here, submicrometer nano-ESI emitter tips are used for native-MS of membrane proteins solubilized in both nonionic and ionic detergent solutions. With the submicrometer nano-ESI emitter tips, resolved charge-state distributions of membrane protein ions are obtained from a 150 mM NaCl, 25 mM Tris-HCl with 1.1% octyl glucoside solution. The relative abundances of NaCl and detergent cluster ions at high m /z are significantly reduced with the submicrometer emitters compared with larger nano-ESI emitters that are commonly used. This technique is beneficial for significantly decreasing the abundances (by two to three orders of magnitude compared with the larger tip size: 1.6 μm) of detergent cluster ions formed from aqueous ammonium acetate solutions containing detergents that can overlap with the membrane protein ion signal. Resolved charge-state distributions of membrane protein ions from aqueous ammonium acetate solutions containing ionic detergents were obtained with the submicrometer nano-ESI emitters; this is the first report of native-MS of membrane proteins solubilized by ionic detergents. Graphical Abstract.

Fluorene biodegradation and identification of transformation products by white-rot fungus Armillaria sp. F022.

PubMed

Hadibarata, Tony; Kristanti, Risky Ayu

2014-06-01

A diverse surfactant, including the nonionic Tween 80 and Brij 30, the anionic sodium dodecyl sulphate, the cationic surfactant Tetradecyltrimethylammonium bromide, and biosurfactant Rhamnolipid were investigated under fluorine-enriched medium by Armilaria sp. F022. The cultures were performed at 25 °C in malt extract medium containing 1 % of surfactant and 5 mg/L of fluorene. The results showed among the tested surfactants, Tween-80 harvested the highest cell density and obtained the maximum specific growth rate. This due Tween-80 provide a suitable carbon source for fungi. Fluorane was also successfully eliminated (>95 %) from the cultures within 30 days in all flasks. During the experiment, laccase production was the highest among other enzymes and Armillaria sp. F022-enriched culture containing Non-ionic Tween 80 showed a significant result for laccase activity (1,945 U/L). The increased enzyme activity was resulted by the increased biodegradation activity as results of the addition of suitable surfactants. The biotransformation of fluorene was accelerated by Tween 80 at the concentration level of 10 mg/L. Fluorene was initially oxidized at C-2,3 positions resulting 9-fluorenone. Through oxidative decarboxylation, 9-fluorenone subjected to meta-cleavage to form salicylic acid. One metabolite detected in the end of experiment, was identified as catechol. Armillaria sp. F022 evidently posses efficient, high effective degrader and potential for further application on the enhanced bioremediation technologies for treating fluorene-contaminated soil.

Self-nanoemulsifying performance of two grades of Lauroglycol (Lauroglycol-90 and Lauroglycol-FCC) in the presence of mixed nonionic surfactants.

PubMed

Shakeel, Faiyaz; Haq, Nazrul; Alanazi, Fars K; Alsarra, Ibrahim A

2014-11-01

The present study was undertaken to evaluate the impact of various combinations of nonionic surfactants on self-nanoemulsifying performance of two grades of Lauroglycol (Lauroglycol-90 and Lauroglycol-FCC) in glibenclamide (GBN) nanoemulsion. Formulations (L1-L30) were prepared by spontaneous emulsification method. Prepared formulations were subjected to thermodynamic stability and self-nanoemulsification test. Results of thermodynamic stability and self-nanoemulsification tests were confirmed by further characterization of these formulations in terms of droplet size, viscosity, refractive index and % transmittance. Formulations prepared with Labrasol, HCO-60 and Gelucire-44/14 were found to be suitable for self-emulsifying drug delivery system only whereas those prepared with Tween-80 and Cremophor-EL were found to be suitable for self-nanoemulsifying or self-microemulsifying drug delivery system of GBN with respect to Lauroglycol-90 or Lauroglycol-FCC. Formulation L24 (Lauroglycol-FCC/Tween-80/ethanol/water) was optimized as best formulation for self-nanoemulsifying drug delivery system of GBN. These results indicated that Tween-80 could be the best surfactant in terms of self-nanoemulsification.

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.

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.

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

Effects of Detergents on Catalytic Activity of Human Endometase/Matrilysin-2, a Putative Cancer Biomarker†

PubMed Central

Park, Hyun I.; Lee, Seakwoo; Ullah, Asad; Cao, Qiang; Sang, Qing-Xiang Amy

2009-01-01

Matrix metalloproteinases (MMPs) are a family of hydrolytic enzymes that play significant roles in development, morphogenesis, inflammation, and cancer invasion. Endometase (matrilysin 2 or MMP-26) is a putative early biomarker for human carcinomas. The effects of the ionic and nonionic detergents on catalytic activity of endometase were investigated. The hydrolytic activity of endometase was detergent concentration-dependent exhibiting a bell-shaped curve with its maximum activity near the critical micelle concentration (CMC) of nonionic detergents tested. The effect of Brij-35 on human gelatinase B (MMP-9), matirilysin (MMP-7), and membrane-type 1 MMP (MT1-MMP) was further explored. Their maximum catalysis was observed near the CMC of Brij-35 (~90 μM). Their IC50 values were above the CMC. The inhibition mechanism of MMP-7, MMP-9, and MT1-MMP by Brij-35 was mixed-type as determined by Dixon’s plot, however, that of endometase was non-competitive with a Ki value of 240 μM. The catalytic activities of MMPs are influenced by detergents. Monomer of detergents may activate and stabilize MMPs to enhance catalysis, but micelle of detergents may sequester enzyme and block substrate binding site to impede catalysis. Under physiological conditions lipid or membrane microenvironment may regulate enzymatic activity. PMID:19818727

Non-ionic Surfactants and Non-Catalytic Protein Treatment on Enzymatic Hydrolysis of Pretreated Creeping Wild Ryegrass

NASA Astrophysics Data System (ADS)

Zheng, Yi; Pan, Zhongli; Zhang, Ruihong; Wang, Donghai; Jenkins, Bryan

Our previous research has shown that saline Creeping Wild Ryegrass (CWR), Leymus triticoides, has a great potential to be used for bioethanol production because of its high fermentable sugar yield, up to 85% cellulose conversion of pretreated CWR. However, the high cost of enzyme is still one of the obstacles making large-scale lignocellulosic bioethanol production economically difficult. It is desirable to use reduced enzyme loading to produce fermentable sugars with high yield and low cost. To reduce the enzyme loading, the effect of addition of non-ionic surfactants and non-catalytic protein on the enzymatic hydrolysis of pretreated CWR was investigated in this study. Tween 20, Tween 80, and bovine serum albumin (BSA) were used as additives to improve the enzymatic hydrolysis of dilute sulfuric-acid-pretreated CWR. Under the loading of 0.1 g additives/g dry solid, Tween 20 was the most effective additive, followed by Tween 80 and BSA. With the addition of Tween 20 mixed with cellulase loading of 15 FPU/g cellulose, the cellulose conversion increased 14% (from 75 to 89%), which was similar to that with cellulase loading of 30 FPU/g cellulose and without additive addition. The results of cellulase and BSA adsorption on the Avicel PH101, pretreated CWR, and lignaceous residue of pretreated CWR support the theory that the primary mechanism behind the additives is prevention of non-productive adsorption of enzymes on lignaceous material of pretreated CWR. The addition of additives could be a promising technology to improve the enzymatic hydrolysis by reducing the enzyme activity loss caused by non-productive adsorption.

Pretreatment of wheat straw by nonionic surfactant-assisted dilute acid for enhancing enzymatic hydrolysis and ethanol production.

PubMed

Qi, Benkun; Chen, Xiangrong; Wan, Yinhua

2010-07-01

Pretreating wheat straw (WS) with combined use of varied sulfuric acid concentration (0-3%, w/v) and Tween 20 concentration (0-1%) was investigated in an attempt to enhance the hydrolysis and fermentability of pretreated WS. Enzymatic hydrolysis yield of glucan and xylan and ethanol production by simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) were significantly affected by the amount of Tween 20 added during acid pretreatment. Any further addition of Tween 20 in either hydrolysis stage or fermentation stage only led to small increase in glucan conversion and ethanol production. Determination of adsorption of cellulases during hydrolysis showed that Tween 20-assisted acid treated straw solution contained more free cellulases than individual acid treated straw solution, indicating that modification of lignin surface by Tween 20 added during pretreatment likely occurred. In addition, the effects of pretreatment conditions on overall recovery of glucose and xylose after pretreatment and enzymatic hydrolysis were also investigated. Copyright 2010 Elsevier Ltd. All rights reserved.

A prospective analysis of co-processed non-ionic surfactants in enhancing permeability of a model hydrophilic drug.

PubMed

Alvi, Mohammed M; Chatterjee, Parnali

2014-04-01

Paracellular route is a natural pathway for the transport of many hydrophilic drugs and macromolecules. The purpose of this study was to prospectively evaluate the ability of novel co-processed non-ionic surfactants to enhance the paracellular permeability of a model hydrophilic drug metformin using Caco-2 (human colonic adenocarcinoma) cell model. A three-tier screen was undertaken to evaluate the co-processed blends based on cytotoxicity, cellular integrity, and permeability coefficient. The relative contribution of the paracellular and the transcellular route in overall transport of metformin by co-processed blends was determined. Immunocytochemistry was conducted to determine the distribution of tight-junction protein claudin-1 after incubation with the co-processed blends. It was found that novel blends of Labrasol and Transcutol-P enhanced metformin permeability by approximately twofold with transient reduction in the transepithelia electrical resistance (TEER) and minimal cytotoxicity compared with the control, with the paracellular pathway as the major route of metformin transport. Maximum permeability of metformin (∼10-fold) was mediated by Tween-20 blends along with >75% reduction in the TEER which was irreversible over 24-h period. A shift in metformin transport from the paracellular to the transcellular route was observed with some Tween-20 blends. Immunocytochemical analysis revealed rearrangement of the cellular borders and fragmentation on treatment with Tween-20 blends. In conclusion, cytotoxicity, cellular integrity, and permeability of the hydrophilic drugs can be greatly influenced by the polyoxyethylene residues and medium chain fatty acids in the non-ionic surfactants at clinically relevant concentrations and therefore should be thoroughly investigated prior to their inclusion in formulations.

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.

Association of a GPI-anchored protein with detergent-resistant membranes facilitates its trafficking through the early secretory pathway.

PubMed

Hein, Zeynep; Hooper, Nigel M; Naim, Hassan Y

2009-01-15

Membrane microdomains are implicated in the trafficking and sorting of several membrane proteins. In particular GPI-anchored proteins cluster into Triton X-100 resistant, cholesterol- and sphingolipid-rich membrane microdomains and are sorted to the apical membrane. A growing body of evidence has pointed to the existence of other types of microdomains that are insoluble in detergents, such as Lubrol WX and Tween-20. Here, we report on the role of detergent-resistant membranes formed at early stages in the biosynthesis of membrane dipeptidase (MDP), a GPI-anchored protein, on its trafficking and sorting. Pulse-chase experiments revealed a retarded maturation rate of the GPI-anchor deficient mutant (MDPDeltaGPI) as compared to the wild type protein (wtMDP). However, Golgi to cell surface delivery rate did not show a significant difference between the two variants. On the other hand, early biosynthetic forms of wtMDP were partially insoluble in Tween-20, while MDPDeltaGPI was completely soluble. The lack of association of MDPDeltaGPI with detergent-resistant membranes prior to maturation in the Golgi and the reduction in its trafficking rate strongly suggest the existence of an early trafficking control mechanisms for membrane proteins operating at a level between the endoplasmic reticulum and the cis-Golgi.

Homologous ELISA for detection of oligomeric human TNF: properties of the assay.

PubMed

Petyovka, N; Lyach, L; Voitenok, N N

1995-10-26

In order to quantify oligomeric human tumor necrosis factor-alpha (TNF), we have developed a sensitive homologous enzyme-linked immunosorbent assay (Hm-ELISA) using the same monoclonal antibody (MoAb) for both solid and liquid phase. Different anti-TNF MoAb have been compared in terms of their efficacy in the Hm-ELISA, affinity, neutralization capacity and epitope specificity. The data suggest, that effectiveness in the Hm-ELISA may represent a novel characteristic of MoAb. Of the MoAbs tested, 5 N was capable of recognizing oligomeric TNF in the Hm-ELISA with a detection limit of 15 pg/ml. Furthermore, using Hm-ELISA against human TNF, interleukin-8 (IL-8) and lymphotoxin, we have demonstrated that these cytokines are oligomeric in physiological solutions, but are converted into monomeric forms in the presence of the non-ionic detergent Tween 20. High salt buffer was employed to abrogate a nonspecific false positive reaction in the Hm-ELISA found in nearly half of the plasma samples obtained from healthy subjects. Finally, a good correlation between the Hm-ELISA and the L929 bioassay was observed for natural and recombinant TNF measured in human plasma.

Enhanced biodegradation of asphalt in the presence of Tween surfactants, Mn(2+) and H2O2 by Pestalotiopsis sp. in liquid medium and soil.

PubMed

Yanto, Dede Heri Yuli; Tachibana, Sanro

2014-05-01

Asphalt and fractions thereof can contaminate water and soil environments. Forming as residues in distillation products in crude oil refineries, asphalts consist mostly of asphaltene instead of aliphatics, aromatics, and resins. The high asphaltene content might be responsible for the decrease in bioavailability to microorganisms and therefore reduce the biodegradability of asphalt in the environment. In this study, the effect on asphalt biodegradation by Pestalotiopsis sp. in liquid medium and soil of nonionic Tween surfactants in the presence of Mn2+ and H2O2 was examined. The degradation was enhanced by Tween 40 or Tween 80 (0.1%) in the presence of Mn2+ (1 mM) and H2O2 (0.05 mM). A Tween surfactant, Mn2+, and H2O2 can overcome bioavailability-mediated constraints and increase ligninolytic activities, particularly manganese peroxidase and laccase activities. The study is significant for the bioremediation of asphalt and/or viscous-crude oil-contaminated environments. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Host Response to a Clinical MDR Mycobacterial Strain Cultured in a Detergent-Free Environment: A Global Transcriptomics Approach.

PubMed

Leisching, Gina; Pietersen, Ray-Dean; Mpongoshe, Vuyiseka; van Heerden, Carel; van Helden, Paul; Wiid, Ian; Baker, Bienyameen

2016-01-01

During Mycobacterium tuberculosis (M.tb) infection, the initial interactions between the pathogen and the host cell determines internalization and innate immune response events. It is established that detergents such as Tween alter the mycobacterial cell wall and solubilize various lipids and proteins. The implication of this is significant since induced changes on the cell wall affect macrophage uptake and the immune response to M.tb. Importantly, during transmission between hosts, aerosolized M.tb enters the host in its native form, i.e. in a detergent-free environment, thus in vitro and in vivo studies should mimic this as closely as possible. To this end, we have optimized a procedure for growing and processing detergent-free M.tb and assessed the response of murine macrophages (BMDM) infected with multi drug-resistant M.tb (R179 Beijing 220 clinical isolate) using RNAseq. We compared the effects of the host response to M.tb cultured under standard laboratory conditions (Tween 80 containing medium -R179T), or in detergent-free medium (R179NT). RNAseq comparisons reveal 2651 differentially expressed genes in BMDMs infected with R179T M.tb vs. BMDMs infected with R179NT M.tb. A range of differentially expressed genes involved in BMDM receptor interaction with M.tb (Mrc1, Ifngr1, Tlr9, Fpr1 and Itgax) and pro-inflammatory cytokines/chemokines (Il6, Il1b, Tnf, Ccl5 and Cxcl14) were selected for analysis through qPCR. BMDMs infected with R179NT stimulate a robust inflammatory response. Interestingly, R179NT M.tb induce transcription of Fpr1, a receptor which detects bacterial formyl peptides and initiates a myriad of immune responses. Additionally we show that the host components Cxcl14, with an unknown role in M.tb infection, and Tlr9, an emerging role player, are only stimulated by infection with R179NT M.tb. Taken together, our results suggest that the host response differs significantly in response to Tween 80 cultured M.tb and should therefore not be used in infection experiments.

Effects of surfactants on the formation of gelatin nanofibres for controlled release of curcumin.

PubMed

Deng, Lingli; Kang, Xuefan; Liu, Yuyu; Feng, Fengqin; Zhang, Hui

2017-09-15

This work studied the effects of non-ionic Tween 80, anionic sodium dodecyl sulfonate (SDS) and cationic cetyltrimethyl ammonium bromide (CTAB) surfactants on the morphology of electrospun gelatin nanofibres, and on the release behaviour, antioxidant activity and antimicrobial activity of encapsulated curcumin. Scanning electron micrographs showed that addition of SDS significantly increased the nanofibre diameter. Fourier transform infrared and differential scanning calorimetry analysis indicated that gelatin and SDS intimately interacted via electrostatic and hydrophobic interactions. However, these interactions inhibited the release of curcumin from the nanofibres with SDS, while CTAB and Tween 80 both facilitated the release. SDS and Tween 80 showed protective effects on curcumin from the attack of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radicals, and the increased release of curcumin from nanofibres with CTAB or Tween 80 resulted in a higher reducing power. The antimicrobial activity results suggested that the curcumin encapsulated gelatin nanofibres with CTAB exhibited effective inhibition against Staphylococcus aureus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lung gas volumes and expiratory time constant in immature newborn rabbits treated with natural or synthetic surfactant or detergents.

PubMed

Bongrani, S; Fornasier, M; Papotti, M; Razzetti, R; Robertson, B

1994-01-01

Immature newborn rabbits delivered at a gestational age of 27 days were tracheotomized and treated, via the tracheal cannula, with clinically recommended doses of natural or synthetic surfactant (Curosurf and Exosurf, respectively). Littermates received 0.1% tyloxapol, 5% Tween 20, or saline. The dose volume of Curosurf was 2.5 ml/kg, that of the other materials 5 ml/kg. Animals were kept in a multiplethysmograph system and ventilated for 30 min with a standardized sequence of insufflation pressures. End-expiratory lung gas volume was calculated at the end of the experiment from measurements of lung weight and total lung volume. Tidal volumes were significantly improved in all groups of animals receiving surfactant or detergents. However, expiratory time constant (determined from the tidal volume tracing) was significantly longer, and end-expiratory gas volume significantly larger, in animals treated with Curosurf than in those receiving Exosurf or detergents. These differences were confirmed by semiquantitative evaluation of alveolar air expansion in histological sections. In addition, airway epithelial necrosis was reduced in animals receiving Curosurf, Exosurf, or Tween 20, but not in animals treated with tyloxapol. The discrepancy between improvements in tidal volume, expiratory time constant, and end-expiratory gas volume reflects failure of lung stabilization in animals treated with Exosurf or detergents, probably due to absence of specific hydrophobic proteins in the synthetic products.

The vesicle-to-micelle transition of phosphatidylcholine vesicles induced by nonionic detergents: effects of sodium chloride, sucrose and urea.

PubMed

Walter, A; Kuehl, G; Barnes, K; VanderWaerdt, G

2000-11-23

The vesicle-to-micelle transition of egg phosphatidylcholine LUVs induced by octylglucoside was studied in buffers with 0-4 M sodium chloride, sucrose or urea. We used both light scattering and fluorescent probes to follow the lipid-detergent complexes in these buffers. The vesicle-to-micelle transition process was fundamentally the same in each solute. However, the detergent-to-lipid ratio required for micelle formation shifted in ways that depended on the aqueous solute. The partitioning of octylglucoside between the vesicles and the aqueous phase was primarily determined by the change in its critical micelle concentration (cmc) induced by each solute. Specifically, the cmc decreased in high salt and sucrose buffers but increased in high concentrations of urea. Cmc for two additional nonionic detergents, decyl- and dodecyl-maltoside, and three zwittergents (3-12, 3-14 and 3-16) were determined as a function of concentration for each of the solutes. In all cases NaCl and sucrose decreased the solubility of the detergents, whereas urea increased their solubilities. The effects clearly depended on acyl chain length in urea-containing solutions, but this dependence was less clear with increasing NaCl and sucrose concentrations. The contributions of these solutes to solubility and to interfacial interactions in the bilayers, pure and mixed micelles are considered.

Nanoemulsions prepared by a low-energy emulsification method applied to edible films

USDA-ARS?s Scientific Manuscript database

Catastrophic phase inversion (CPI) was used as a low-energy emulsification method to prepare oil-in-water (O/W) nanoemulsions in a lipid (Acetem)/water/nonionic surfactant (Tween 60) system. CPIs in which water-in-oil emulsions (W/O) are transformed into oil-in-water emulsions (O/W) were induced by ...

Millimeter-wave sensor based on a λ/2-line resonator for identification and dielectric characterization of non-ionic surfactants

PubMed Central

Rodilla, H.; Kim, A. A.; Jeffries, G. D. M.; Vukusic, J.; Jesorka, A.; Stake, J.

2016-01-01

Studies of biological and artificial membrane systems, such as niosomes, currently rely on the use of fluorescent tags, which can influence the system under investigation. For this reason, the development of label-free, non-invasive detection techniques is of great interest. We demonstrate an open-volume label-free millimeter-wave sensing platform based on a coplanar waveguide, developed for identification and characterization of niosome constituents. A design based on a λ/2-line resonator was used and on-wafer measurements of transmission and reflection parameters were performed up to 110 GHz. Our sensor was able to clearly distinguish between common niosome constituents, non-ionic surfactants Tween 20 and Span 80, measuring a resonance shift of 3 GHz between them. The complex permittivities of the molecular compounds have been extracted. Our results indicate insignificant frequency dependence in the investigated frequency range (3 GHz – 110 GHz). Values of permittivity around 3.0 + 0.7i and 2.2 + 0.4i were obtained for Tween 20 and Span 80, respectively. PMID:26786983

Millimeter-wave sensor based on a λ/2-line resonator for identification and dielectric characterization of non-ionic surfactants.

PubMed

Rodilla, H; Kim, A A; Jeffries, G D M; Vukusic, J; Jesorka, A; Stake, J

2016-01-20

Studies of biological and artificial membrane systems, such as niosomes, currently rely on the use of fluorescent tags, which can influence the system under investigation. For this reason, the development of label-free, non-invasive detection techniques is of great interest. We demonstrate an open-volume label-free millimeter-wave sensing platform based on a coplanar waveguide, developed for identification and characterization of niosome constituents. A design based on a λ/2-line resonator was used and on-wafer measurements of transmission and reflection parameters were performed up to 110 GHz. Our sensor was able to clearly distinguish between common niosome constituents, non-ionic surfactants Tween 20 and Span 80, measuring a resonance shift of 3 GHz between them. The complex permittivities of the molecular compounds have been extracted. Our results indicate insignificant frequency dependence in the investigated frequency range (3 GHz - 110 GHz). Values of permittivity around 3.0 + 0.7i and 2.2 + 0.4i were obtained for Tween 20 and Span 80, respectively.

Reductive dechlorination of chlorobenzenes in surfactant-amended sediment slurries

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

Van Hoof, P.L.; Jafvert, C.T.

1996-11-01

Microbial anaerobic dechlorination of hexachlorobenzene (HCB) was examined in sediment slurries amended with two classes of nonionic surfactant, polyoxyethylene (POE) sorbitan fatty acid esters (Tweens) and POE alcohols (Brijs). The rationale for surfactant addition was to increase the bioavailability of highly sorbed organic pollutants to degrading microorganisms by enhancing their solubility. The solubility of HCB was initially enhanced via micellar partitioning; however, primary degradation of most surfactants occurred within 10 d. Dechlorination activity was significantly reduced at POE alcohol concentrations above the critical micelle concentration (cmc), with or without the occurrence of surfactant degradation. Tween 80 decreased HCB dechlorination atmore » concentrations significantly above the cmc. At concentrations closer to the cmc, Tween 80 increased dechlorination rate constants four- to fivefold in acclimated slurries. Additions of Tween 80 at or below the cmc stimulated dechlorination activity in unacclimated slurries that exhibited very little activity in unamended controls. An average of 89% of HCB was dechlorinated after 90 d, compared to 20% in unamended sediments. No effect was observed for POE alcohols at these sub-cmc levels. The lack of a stimulated response for the POE alcohols suggests that Tween 80 may not be acting simply as a source of carbon or energy.« less

Effects of Lubrol detergents on adenylate cyclases.

PubMed

Bär, H P; Kulshrestha, S

1975-04-01

The nonionic detergent Lubrol WX showed diverse, concentration-dependent effects onbasal and stimulated adenylate cyclases. Above concentrations of 0.001-0.01% Lubrol WX, the basal activity of cyclase from Ehrlich ascites cells was inhibed about 50%, and that from rat fat cells was doubled. In both cases, hormonal sensitivity was lost at 0.01%. These effects were reversed upon dilution of the detergent. It is suggested that solubilization of adenylate cyclases at such low concentrations of Lubrol should be attempted since it is conceivable that loss of hormone sensitivity may then be reversible. Different Lubrol-type detergents may also offer centain advantages, since Lubrol PX effects were not identical with those of Lubrol WX.

Expression of a Deschampsia antarctica Desv. Polypeptide with Lipase Activity in a Pichia pastoris Vector

PubMed Central

Rabert, Claudia; Gutiérrez-Moraga, Ana; Navarrete-Gallegos, Alejandro; Navarrete-Campos, Darío; Bravo, León A.; Gidekel, Manuel

2014-01-01

The current study isolated and characterized the Lip3F9 polypeptide sequence of Deschampsia antarctica Desv. (GeneBank Accession Number JX846628), which was found to be comprised of 291 base pairs and was, moreover, expressed in Pichia pastoris X-33 cells. The enzyme was secreted after 24 h of P. pastoris culture incubation and through induction with methanol. The expressed protein showed maximum lipase activity (35 U/L) with an optimal temperature of 37 °C. The lipase-expressed enzyme lost 50% of its specific activity at 25 °C, a behavior characteristic of a psychrotolerant enzyme. Recombinant enzyme activity was measured in the presence of ionic and non-ionic detergents, and a decrease in enzyme activity was detected for all concentrations of ionic and non-ionic detergents assessed. PMID:24514564

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.

Anaerobic Biodegradation of Detergent Surfactants

PubMed Central

Merrettig-Bruns, Ute; Jelen, Erich

2009-01-01

Detergent surfactants can be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have strictly anaerobic conditions. This review gives an overview on anaerobic biodegradation processes, the methods for testing anaerobic biodegradability, and the anaerobic biodegradability of different detergent surfactant types (anionic, nonionic, cationic, amphoteric surfactants).

Effect of three kinds of surfactants and β-cyclodextrin on the phytoremediation of BDE-209 contaminated sediment

NASA Astrophysics Data System (ADS)

Zhao, Liangyuan; Guo, Weijie; Zhao, Weihua; Long, Meng; Li, Huan

2017-05-01

Plant-accelerated removal of BDE-209 from sediment by aquatic macrophyte Scirpus validus Vahl in the presence of a cationic-surfactant (CTAB), an anionic-surfactant (SDS), a nonionic-surfactant (Tween 80) and β-cyclodextrin (β-CD) at the concentrations ranged from 300 mg/kg to 1000 mg/kg were investigated. Significantly negative effect were not observed for the growth of S. validus in terms of plant height and stem diatemeter, which indicated that it is preferable for CTAB, SDS, Tween 80 and β-cyclodextrin to be utilized as the BDE-209 phytoremediation amendment. Furthermore, CTAB, SDS and Tween 80 in the certain concentrations significantly enhanced the phytoremediation efficiencies and 11.78-19.33% of increase in BDE-209 removal rates was obtained. Significantly enhance of BDE-209 phytoremediation efficiency was not observed in the added β-CD concentration ranges. Results obtained from this study provided some insight with regard to the feasibility of phytoremediation for BDE-209 contaminated sediments with addition of suitable solubilizers, especially Tween 80.

Enzymatic activity of a subtilisin homolog, Tk-SP, from Thermococcus kodakarensis in detergents and its ability to degrade the abnormal prion protein

PubMed Central

2013-01-01

Background Tk-SP is a member of subtilisin-like serine proteases from a hyperthermophilic archaeon Thermococcus kodakarensis. It has been known that the hyper-stable protease, Tk-SP, could exhibit enzymatic activity even at high temperature and in the presence of chemical denaturants. In this work, the enzymatic activity of Tk-SP was measured in the presence of detergents and EDTA. In addition, we focused to demonstrate that Tk-SP could degrade the abnormal prion protein (PrPSc), a protease-resistant isoform of normal prion protein (PrPC). Results Tk-SP was observed to maintain its proteolytic activity with nonionic surfactants and EDTA at 80°C. We optimized the condition in which Tk-SP functions efficiently, and demonstrated that the enzyme is highly stable in the presence of 0.05% (w/v) nonionic surfactants and 0.01% (w/v) EDTA, retaining up to 80% of its activity. Additionally, we also found that Tk-SP can degrade PrPSc to a level undetectable by western-blot analysis. Conclusions Our results indicate that Tk-SP has a great potential for technological applications, such as thermo-stable detergent additives. In addition, it is also suggested that Tk-SP-containing detergents can be developed to decrease the secondary infection risks of transmissible spongiform encephalopathies (TSE). PMID:23448268

Comparative proteomics reveal the mechanism of Tween80 enhanced phenanthrene biodegradation by Sphingomonas sp. GY2B.

PubMed

Liu, Shasha; Guo, Chuling; Dang, Zhi; Liang, Xujun

2017-03-01

Previous study concerning the effects of surfactants on phenanthrene biodegradation focused on observing the changes of cell characteristics of Sphingomonas sp. GY2B. However, the impact of surfactants on the expression of bacterial proteins, controlling phenanthrene transport and catabolism, remains obscure. To overcome the knowledge gap, comparative proteomic approaches were used to investigate protein expressions of Sphingomonas sp. GY2B during phenanthrene biodegradation in the presence and absence of a nonionic surfactant, Tween80. A total of 23 up-regulated and 19 down-regulated proteins were detected upon Tween80 treatment. Tween80 could regulate ion transport (e.g. H + ) in cell membrane to provide driving force (ATP) for the transmembrane transport of phenanthrene thus increasing its uptake and biodegradation by GY2B. Moreover, Tween80 probably increased GY2B vitality and growth by inducing the expression of peptidylprolyl isomerase to stabilize cell membrane, increasing the abundances of proteins involved in intracellular metabolic pathways (e.g. TCA cycle), as well as decreasing the abundances of translation/transcription-related proteins and cysteine desulfurase, thereby facilitating phenanthrene biodegradation. This study may facilitate a better understanding of the mechanisms that regulate surfactants-enhanced biodegradation of PAHs at the proteomic level. Copyright © 2016 Elsevier Inc. All rights reserved.

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

Sequential application of chelating agents and innovative surfactants for the enhanced electroremediation of real sediments from toxic metals and PAHs.

PubMed

Hahladakis, John N; Lekkas, Nikolaos; Smponias, Andreas; Gidarakos, Evangelos

2014-06-01

This study focused on the sequential application of a chelating agent (citric acid) followed by a surfactant in the simultaneous electroremediation of real contaminated sediments from toxic metals and Polycyclic Aromatic Hydrocarbons (PAHs). Furthermore, the efficiency evaluation of two innovative non-ionic surfactants, commercially known as Poloxamer 407 and Nonidet P40, was investigated. The results indicated a removal efficacy of approximately 43% and 48% for the summation of PAHs (SUM PAHs), respectively for the aforementioned surfactants, much better than the one obtained by the use of Tween 80 (nearly 21%). Individual PAHs (e.g. fluorene) were removed in percentages that reached almost 84% and 92% in the respective electrokinetic experiments when these new surfactants were introduced. In addition, the combined-enhanced sequential electrokinetic treatment with citric acid improved dramatically the removal of Zn and As, compared to the unenhanced run, but did not favor the other toxic metals examined. Since no improvement in metal removal percentages occurred when Tween 80 was used, significant contribution to this matter should also be attributed to the solubilization capacity of these innovative, in electrokinetic remediation, non-ionic surfactants. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Evaluation of a New Lipase from Staphylococcus sp. for Detergent Additive Capability

PubMed Central

Chauhan, Mamta; Chauhan, Rajinder Singh; Garlapati, Vijay Kumar

2013-01-01

Lipases are the enzymes of choice for laundry detergent industries owing to their triglyceride removing ability from the soiled fabric which eventually reduces the usage of phosphate-based chemical cleansers in the detergent formulation. In the present study, a partially purified bacterial lipase from Staphylococcus arlettae JPBW-1 isolated from the rock salt mine has been assessed for its triglyceride removing ability by developing a presoak solution so as to use lipase as an additive in laundry detergent formulations. The effects of selected surfactants, commercial detergents, and oxidizing agents on lipase stability were studied in a preliminary evaluation for its further usage in the industrial environment. Partially purified lipase has shown good stability in presence of surfactants, commercial detergents, and oxidizing agents. Washing efficiency has been found to be enhanced while using lipase with 0.5% nonionic detergent than the anioinic detergent. The wash performance using 0.5% wheel with 40 U lipase at 40°C in 45 min results in maximum oil removal (62%) from the soiled cotton fabric. Hence, the present study opens the new era in enzyme-based detergent sector for formulation of chemical-free detergent using alkaline bacterial lipase. PMID:24106703

Evaluation of a new lipase from Staphylococcus sp. for detergent additive capability.

PubMed

Chauhan, Mamta; Chauhan, Rajinder Singh; Garlapati, Vijay Kumar

2013-01-01

Lipases are the enzymes of choice for laundry detergent industries owing to their triglyceride removing ability from the soiled fabric which eventually reduces the usage of phosphate-based chemical cleansers in the detergent formulation. In the present study, a partially purified bacterial lipase from Staphylococcus arlettae JPBW-1 isolated from the rock salt mine has been assessed for its triglyceride removing ability by developing a presoak solution so as to use lipase as an additive in laundry detergent formulations. The effects of selected surfactants, commercial detergents, and oxidizing agents on lipase stability were studied in a preliminary evaluation for its further usage in the industrial environment. Partially purified lipase has shown good stability in presence of surfactants, commercial detergents, and oxidizing agents. Washing efficiency has been found to be enhanced while using lipase with 0.5% nonionic detergent than the anioinic detergent. The wash performance using 0.5% wheel with 40 U lipase at 40°C in 45 min results in maximum oil removal (62%) from the soiled cotton fabric. Hence, the present study opens the new era in enzyme-based detergent sector for formulation of chemical-free detergent using alkaline bacterial lipase.

Inhibition of lipase-catalyzed hydrolysis of emulsified triglyceride oils by low-molecular weight surfactants under simulated gastrointestinal conditions.

PubMed

Li, Yan; McClements, David Julian

2011-10-01

The effect of low-molecular weight surfactants on the digestibility of lipids in protein-stabilized corn oil-in-water emulsions was studied using an in vitro digestion model. The impact of non-ionic (Tween 20, Tween 80, Brij35), anionic (SDS), and cationic (DTAB) surfactants on the rate and extent of lipid digestion was studied. All surfactants were found to inhibit lipid digestion at sufficiently high concentrations, with half-maximal inhibitory concentrations (IC50) of 1.2% for Tween 20, 0.7% for Tween 80, 2.8% for Brij35, 1.1% for SDS, and 1.4% for DTAB. The effectiveness of the surfactants at inhibiting lipid digestion was therefore not strongly correlated to the electrical characteristics of the surfactant head group, since the IC50 increased in the following order: Tween 80>SDS>Tween 20>DTAB>Brij35. The ability of these low-molecular weight surfactants to inhibit lipid digestion was attributed to a number of potential mechanisms: (i) prevention of lipase/co-lipase adsorption to the oil-water interface; (ii) formation of interfacial complexes; (iii) direct interaction and inactivation of lipase/co-lipase. Interestingly, DTAB increased the rate and extent of lipid digestion when present at relatively low concentrations. This may have been because this cationic surfactant facilitated the adsorption of lipase to the droplet surfaces through electrostatic attraction, or it bound directly to the lipase molecule thereby changing its structure and activity. A number of the surfactants themselves were found to be susceptible to enzyme digestion by pancreatic enzymes in the absence of lipids: Tween 20, Tween 80, Brij35, and DTAB. This work has important implications for the development of emulsion-based delivery systems for food and pharmaceutical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

Selecting Surrogates for an Alkylphenol Ethoxylate Analytical Method in Sewage and Soil Matrices

EPA Science Inventory

Alkylphenol ethoxylates (APEs) are nonionic surfactants commonly used in industrial detergents. These products contain complex mixtures of branched and linear chains. APEs and their degradation products, alkylphenols, are highly toxic to aquatic organisms, potentially estrogeni...

Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana.

PubMed

Mwamburi, Lizzy A; Laing, Mark D; Miller, Ray M

2015-03-01

Three non-ionic surfactants: Tween20, Tween80 and Breakthru (®) were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassiana spore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations . Breakthru (®) had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25-30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses.

Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana

PubMed Central

Mwamburi, Lizzy A.; Laing, Mark D.; Miller, Ray M.

2015-01-01

Three non-ionic surfactants: Tween20, Tween80 and Breakthru ® were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassiana spore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations . Breakthru ® had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25–30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses. PMID:26221090

ANALYSIS OF ALKYLPHENOLS AND ALKYLPHENOL ETHOXYLATES WITH SEPARATION OF ETHOXYMERS USING REVERSED PHASE LC/MS

EPA Science Inventory

Alkylphenol polyethoxylates are non-ionic surfactants, widely used in detergents, paints, personal care products, etc., which enter the environment primarily through wastewater treatment systems. Their biodegradation during wastewater treatment leads to the formation of persisten...

Sorption of a nonionic surfactant Tween 80 by minerals and soils.

PubMed

Kang, Soyoung; Jeong, Hoon Young

2015-03-02

Batch experiments were conducted to evaluate Tween 80 sorption by oxides, aluminosilicates, and soils. For oxides, the sorption by silica and alumina follow linear isotherms, and that by hematite follows a Langmuir isotherm. Considering isotherm type and surface coverage, Tween 80 may partition into the silica/alumina-water interface, whereas it may bind to hematite surface sites. Among aluminosilicates, montmorillonite shows the greatest sorption due to the absorption of Tween 80 into interlayers. For other aluminosilicates, it sorbs to surfaces, with the sorption increasing as plagioclase

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

Trypsin from the processing waste of the lane snapper (Lutjanus synagris) and its compatibility with oxidants, surfactants and commercial detergents.

PubMed

Espósito, Talita S; Marcuschi, Marina; Amaral, Ian P G; Carvalho, Luiz B; Bezerra, Ranilson S

2010-05-26

A trypsin from the viscera of the lane snapper (Lutjanus synagris) was purified by heat treatment, fractionation with ammonium sulfate and affinity chromatography. The molecular weight of the enzyme was estimated to be 28.4 kDa (SDS-PAGE). The purified enzyme was capable of hydrolyzing the specific substrate for trypsin benzoyl-arginine-p-nitroanilide (BApNA) and was inhibited by benzamidine and tosyl lysine chloromethyl ketone (TLCK), synthetic trypsin inhibitors and phenylmethylsulfonyl fluoride (PMSF), which is a serine-protease inhibitor. The enzyme exhibited maximal activity at pH 9.0 and 45 degrees C and retained 100% of the activity after incubation at the optimal temperature for 30 min. At a concentration of 10 mM, activity was slightly activated by Ca(2+) and inhibited by the following ions in decreasing order: Cd(2+) > Hg(2+) > Cu(2+) > Zn(2+) > Al(3+). The effects of Ba(2+), K(1+) and Li(1+) proved to be less intensive. Using 1% (w/v) azocasein as substrate, the enzyme revealed high resistance (60% residual activity) when incubated with 10% H(2)O(2) for 75 min. The enzyme retained more than 80% activity after 60 min in the presence of different surfactants (Tween 20, Tween 80 and sodium choleate). The alkaline protease demonstrated compatibility with commercial detergents (7 mg/mL), such as Bem-te-vi, Surf and Ala, retaining more than 50% of initial activity after 60 min at 25 degrees C and 30 min at 40 degrees C. The thermostability and compatibility of this enzyme with commercial detergents suggest a good potentiality for application in the detergent industry.

Effects of absorption enhancers in chloroquine suppository formulations: I. In vitro release characteristics.

PubMed

Onyeji, C O; Adebayo, A S; Babalola, C P

1999-12-01

The need to develop chloroquine suppository formulations that yield optimal bioavailability of the drug has been emphasized. This study demonstrates the effects of incorporation of known absorption-enhancing agents (nonionic surfactants and sodium salicylate) on the in vitro release characteristics of chloroquine from polyethylene glycol (1000:4000, 75:25%, w/w) suppositories. The release rates were determined using a modification of the continuous flow bead-bed dissolution apparatus for suppositories. Results showed that the extent of drug release from suppositories containing any of three surfactants (Tween 20, Tween 80 and Brij 35) was 100%, whereas 88% release was obtained with control formulation (without enhancer) (P<0.05). However, Tween 20 was more effective than Brij 35 and Tween 80 in improving the drug release rate. There was a concentration-dependent effect with Tween 20, and 4% (w/w) of this surfactant was associated with the highest increase in the rate of drug release from the suppositories. Sodium salicylate at a concentration of 25% (w/w) also significantly enhanced the drug release rate, but a higher concentration of the adjuvant markedly reduced both the rate and extent of drug release. Combined incorporation of Tween 20 and sodium salicylate did not significantly modify (P0.05) the rate of drug release when compared to the effect of the more effective single agent. Due to their effects in improving the drug release profiles coupled with their intrinsic absorption-promoting properties, it is suggested that incorporation of 4% (w/w) Tween 20 and/or 25% (w/w) sodium salicylate in the composite polyethylene glycol chloroquine suppository formulations, may result in enhancement of rectal absorption of the drug. This necessitates an in vivo validation.

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.

Hofmeister series salts enhance purification of plasmid DNA by non-ionic detergents

PubMed Central

Lezin, George; Kuehn, Michael R.; Brunelli, Luca

2011-01-01

Ion-exchange chromatography is the standard technique used for plasmid DNA purification, an essential molecular biology procedure. Non-ionic detergents (NIDs) have been used for plasmid DNA purification, but it is unclear whether Hofmeister series salts (HSS) change the solubility and phase separation properties of specific NIDs, enhancing plasmid DNA purification. After scaling-up NID-mediated plasmid DNA isolation, we established that NIDs in HSS solutions minimize plasmid DNA contamination with protein. In addition, large-scale NID/HSS solutions eliminated LPS contamination of plasmid DNA more effectively than Qiagen ion-exchange columns. Large-scale NID isolation/NID purification generated increased yields of high quality DNA compared to alkali isolation/column purification. This work characterizes how HSS enhance NID-mediated plasmid DNA purification, and demonstrates that NID phase transition is not necessary for LPS removal from plasmid DNA. Specific NIDs such as IGEPAL CA-520 can be utilized for rapid, inexpensive and efficient laboratory-based large-scale plasmid DNA purification, outperforming Qiagen-based column procedures. PMID:21351074

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

Influence of Surfactants on Sodium Chloride Crystallization in Confinement

PubMed Central

2017-01-01

We study the influence of different surfactants on NaCl crystallization during evaporation of aqueous salt solutions. We found that at concentrations of sodium chloride close to saturation, only the cationic surfactant CTAB and the nonionic surfactant Tween 80 remain stable. For the nonionic surfactant, the high concentration of salt does not significantly change either the critical micellar concentration (CMC) or the surface tension at the CMC; for the cationic surfactant, the CMC is reduced by roughly 2 orders of magnitude upon adding the salt. The presence of both types of surfactants in the salt solution delays the crystallization of sodium chloride with evaporation. This, in turn, leads to high supersaturation which induces the rapid precipitation of a hopper crystal in the bulk. The crystallization inhibitor role of these surfactants is shown to be mainly due to the passivation of nucleation sites at both liquid/air and solid/liquid interfaces rather than a change in the evaporation rate which is found not to be affected by the presence of the surfactants. The adsorption of surfactants at the liquid/air interface prevents the crystallization at this location which is generally the place where the precipitation of sodium chloride is observed. Moreover, sum frequency generation spectroscopy measurements show that the surfactants are also present at the solid/liquid interface. The incorporation of the surfactants into the salt crystals is investigated using a novel, but simple, method based on surface tension measurements. Our results show that the nonionic surfactant Tween 80 is incorporated in the NaCl crystals but the cationic surfactant CTAB is not. Taken together, these results therefore allow us to establish the effect of the presence of surfactants on sodium chloride crystallization. PMID:28425711

Soaps and detergents: understanding their composition and effect.

PubMed

Kirsner, R S; Froelich, C W

1998-03-01

Soaps have been used for thousands of years as part of religious ceremonies and daily life. Derived from fatty acids or triglycerides (fats or oils) into their alkali derivatives through a process called saponification, soaps are important for healthcare professionals in preventing the spread of disease. Partly due to their alkaline nature, soaps are limited by their irritancy to the skin and their tendency to form insoluble and inactive salts when combined with either hard water or sea water. Therefore, soap alternatives or synthetic detergents have been developed. Detergents are classified into four groups: anionic, cationic, amphoteric, and non-ionic. These four groups are based on the hydrophilic qualities and surfactants they possess. Each group has characteristics that pertain to its main uses, irritancy, and toxicity. Understanding soaps and detergents may assist clinicians in making intelligent choices when using these agents on their patients as either skin cleansers or wound cleansers. Understanding the characteristics of soaps and detergents is especially important when dealing with at-risk patients such as the elderly.

High Efficacy but Low Potency of δ-Opioid Receptor-G Protein Coupling in Brij-58-Treated, Low-Density Plasma Membrane Fragments.

PubMed

Roubalova, Lenka; Vosahlikova, Miroslava; Brejchova, Jana; Sykora, Jan; Rudajev, Vladimir; Svoboda, Petr

2015-01-01

HEK293 cells stably expressing PTX-insensitive δ-opioid receptor-Gi1α (C351I) fusion protein were homogenized, treated with low concentrations of non-ionic detergent Brij-58 at 0°C and fractionated by flotation in sucrose density gradient. In optimum range of detergent concentrations (0.025-0.05% w/v), Brij-58-treated, low-density membranes exhibited 2-3-fold higher efficacy of DADLE-stimulated, high-affinity [32P]GTPase and [35S]GTPγS binding than membranes of the same density prepared in the absence of detergent. The potency of agonist DADLE response was significantly decreased. At high detergent concentrations (>0.1%), the functional coupling between δ-opioid receptors and G proteins was completely diminished. The same detergent effects were measured in plasma membranes isolated from PTX-treated cells. Therefore, the effect of Brij-58 on δ-opioid receptor-G protein coupling was not restricted to the covalently bound Gi1α within δ-opioid receptor-Gi1α fusion protein, but it was also valid for PTX-sensitive G proteins of Gi/Go family endogenously expressed in HEK293 cells. Characterization of the direct effect of Brij-58 on the hydrophobic interior of isolated plasma membranes by steady-state anisotropy of diphenylhexatriene (DPH) fluorescence indicated a marked increase of membrane fluidity. The time-resolved analysis of decay of DPH fluorescence by the "wobble in cone" model of DPH motion in the membrane indicated that the exposure to the increasing concentrations of Brij-58 led to a decreased order and higher motional freedom of the dye. Limited perturbation of plasma membrane integrity by low concentrations of non-ionic detergent Brij-58 results in alteration of δ-OR-G protein coupling. Maximum G protein-response to agonist stimulation (efficacy) is increased; affinity of response (potency) is decreased. The total degradation plasma membrane structure at high detergent concentrations results in diminution of functional coupling between δ-opioid receptors and G proteins.

The Effect of Detergents on the Morphology and Immunomodulatory Activity of Malassezia furfur.

PubMed

Kim, Su-Han; Ko, Hyun-Chang; Kim, Moon-Bum; Kwon, Kyung-Sool; Oh, Chang-Keun

2009-05-01

Several workers have found that Malassezia are capable of suppressing cytokine release and downregulating the phagocytic function of monocytes. But lipid-depleted Malassezia furfur (M. furfur) extracts have also been shown to induce increased production of TNF-alpha, IL-6 and IL-1beta in monocytes. We thought that the detergents in shampoos or soaps could change the composition of the lipid in the M. furfur cell wall. We studied whether detergents affect the morphology of M. furfur and if the inflammatory cytokine profiles change in the monocytes treated with detergent-treated M. furfur. Commonly used detergents such as sodium lauryl sulfate, ammonium lauryl sulfate and tween-80 were respectively added to the modified Leeming-Notman's media. M. furfur was cultivated in each media (detergent-added or untreated). Thereafter, the surface morphology of the yeast was evaluated by scanning and transmission electron microscopy. The cytokine profiles of monocytes, which were treated by M. furfur with or without detergents, were also evaluated. The detergent-treated M. furfur were similar to the lipid-extracted form of M. furfur on the electron microscopic study, with a recessed, withered surface and with thinner and rather electron transparent cell walls than the detergent-untreated M. furfur. The levels of TNF-alpha were higher in monocytes treated with detergent-treated Malassezia than that in the monocytes treated with the detergent-untreated Malassezia (p<0.05). According to the findings in this study, it could be inferred that the detergents in shampoos or soaps affect the lipid layers of the Malassezia cell wall and these lipid-extracted Malassezia induce or aggravate some inflammatory conditions. But to correlate the relationship between detergents and Malassezia-associated diseases, in vivo experiments that will focus on short-term contact with detergents in real life conditions should be done.

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.

Effect of the coexistence of sodium caseinate and Tween 20 as stabilizers of food emulsions at acidic pH.

PubMed

Perugini, Luisa; Cinelli, Giuseppe; Cofelice, Martina; Ceglie, Andrea; Lopez, Francesco; Cuomo, Francesca

2018-02-05

In the present investigation the properties of edible nanoemulsions were studied. Sodium caseinate represents a good candidate for food emulsion preparations thanks to its surface-active properties and because it is perceived as a natural product by consumers. Nevertheless, it is very sensitive to acidic pH close to its isoelectric point and, if used as emulsion stabilizer, this aspect can negatively affect the emulsion stability. In order to prevent this drawback, sodium caseinate was used in combination with a non-ionic surfactant (Tween 20) as emulsifier of oil/water nanoemulsions. For these reasons, nanoemulsions stabilized by Tween 20, sodium caseinate and by a blend of the two emulsifiers were studied and compared according to their response to pH variations. Nanoemulsions were characterized for size of the dispersed phase with variation of time and temperature, for their rheological properties, for surface charge as a function of pH and for protein fluorescence. Noticeably, it was ascertained that, at pH close to caseinate isoelectric point, emulsions stabilized with the blend of caseinate and Tween 20 were more stable, compared with emulsions stabilized only with sodium caseinate. Such behavior was explained according to the composition of the emulsifiers at the oil/water interface where, at acidic pH, the presence of Tween 20 ensured the steric stabilization thus improving the role of sodium caseinate as emulsion stabilizer. Copyright © 2018 Elsevier B.V. All rights reserved.

Interactions of Triton X-100 with sphingomyelin and phosphatidylcholine monolayers: influence of the cholesterol content.

PubMed

Abi-Rizk, Georges; Besson, Françoise

2008-10-15

The presence of microdomains, called lipid rafts, in biological membranes is usually explained by lateral segregation between specific lipids and proteins. These rafts present similarities with the membrane domains isolated by their non-ionic detergent-resistance at 4 degrees C. They are enriched in sphingomyelin and cholesterol as compared with the outer leaflet of eukaryotic cell membranes. To understand the role played by the lipids enriched in rafts in their resistance to solubilization by detergents, the interactions between these lipids and the non-ionic detergent Triton X-100 were studied by using different lipid monolayers at the air-water interface. The influence of Triton X-100 on the Langmuir isotherms (i.e. surface pressure/area isotherms) of monolayers containing sphingomyelin and cholesterol at different mole ratios was analyzed and the results were compared with the influence of Triton X-100 on monolayers containing a phosphatidylcholine bearing a saturated and an unsaturated fatty acid (i.e. palmitoyloleylphosphatidylcholine) and cholesterol. This phosphatidylcholine was chosen since the phosphatidylcholines present in rafts isolated from bovine kidney could contain about 50% of saturated fatty acids. Triton X-100 induces an increase in the condensing effect observed as compared with ideal mixture of phospholipid/cholesterol. Triton X-100-induced changes in the morphology of the monolayers were visualized by Brewster angle microscopy, which confirmed the differences of behavior observed by analyzing the isotherms.

Novel sample preparation method for surfactant containing suppositories: effect of micelle formation on drug recovery.

PubMed

Kalmár, Éva; Ueno, Konomi; Forgó, Péter; Szakonyi, Gerda; Dombi, György

2013-09-01

Rectal drug delivery is currently at the focus of attention. Surfactants promote drug release from the suppository bases and enhance the formulation properties. The aim of our work was to develop a sample preparation method for HPLC analysis for a suppository base containing 95% hard fat, 2.5% Tween 20 and 2.5% Tween 60. A conventional sample preparation method did not provide successful results as the recovery of the drug failed to fulfil the validation criterion 95-105%. This was caused by the non-ionic surfactants in the suppository base incorporating some of the drug, preventing its release. As guidance for the formulation from an analytical aspect, we suggest a well defined surfactant content based on the turbidimetric determination of the CMC (critical micelle formation concentration) in the applied methanol-water solvent. Our CMC data correlate well with the results of previous studies. As regards the sample preparation procedure, a study was performed of the effects of ionic strength and pH on the drug recovery with the avoidance of degradation of the drug during the procedure. Aminophenazone and paracetamol were used as model drugs. The optimum conditions for drug release from the molten suppository base were found to be 100 mM NaCl, 20-40 mM NaOH and a 30 min ultrasonic treatment of the final sample solution. As these conditions could cause the degradation of the drugs in the solution, this was followed by NMR spectroscopy, and the results indicated that degradation did not take place. The determined CMCs were 0.08 mM for Tween 20, 0.06 mM for Tween 60 and 0.04 mM for a combined Tween 20, Tween 60 system. Copyright © 2013 Elsevier B.V. All rights reserved.

Detergents as selective inhibitors and inactivators of enzymes.

PubMed

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

1985-01-01

In order to study the detergent-enzyme interaction and to clarify whether such an interaction produces specific or non-specific effects, we investigated the action of natural and synthetic detergents on enzymatic systems of different levels of complexity (crystalline enzymes, crude homogenates, organ preparations, organisms in toto i.e. rats and germinating seeds). The enzyme-detergent interaction was examined both as a time-independent phenomenon (inhibition) and as a time-dependent phenomenon (inactivation). In in vitro experiments a clear inhibition of pyridine-dependent dehydrogenases by long-chain anionic detergents was found. Cationic detergents have their greatest effect on lipase, LDH, MDH and ICDH from rat liver homogenates. At low concentrations SDS inactivates all the dehydrogenase enzymes studied. With high concentrations (10 mM) of SDS and dodecyltrimethylammonium bromide (C12), there was a sharp and non-specific decrease of enzymatic activities. In the in vivo studies, rats were given detergents to drink; the cationic detergent (C12) was far more effective than SDS with enzymes from both intestine and liver homogenates. SDS and C12 do not seem to interfere with enzyme activities at the beginning of the germination of Pinus pinea and Triticum durum seeds. However a marked reduction of activities does occur at the respective maximum germination times of these seeds. The nonionic detergent is ineffective both as inhibitor and as inactivator.

GDP-GTP exchange processes of G{alpha}i1 protein are accelerated/decelerated depending on the type and the concentration of added detergents.

PubMed

Kubota, Makoto; Tanaka, Takeshi; Kohno, Toshiyuki; Wakamatsu, Kaori

2009-12-01

Although detergents have been widely used in G-protein studies to increase solubility and stability of the protein, we noticed that detergents modulate the nucleotide-binding properties of G-proteins. Hence, we analysed the effects of detergents on guanine nucleotide exchange reactions of Galpha(i1). Lubrol PX, a non-ionic detergent, which has been widely used in nucleotide dissociation/binding assays, was found to accelerate both GDP dissociation and GTPgammaS binding from/to Galpha in parallel at above its critical micelle concentration (cmc). Sodium cholate, an anionic detergent, which have been used to extract G-proteins from animal tissues, decelerated and accelerated GDP dissociation below and above its cmc, respectively. Surprisingly, micellar cholate decelerated GTPgammaS binding, and the binding rate constant was decreased by three orders of magnitude in the presence of 2% cholate. These results demonstrate that the guanine nucleotide exchange reactions of Galpha(i1) are drastically modulated by detergents differently depending on the type and the state (monomeric or micellar) of the detergents and that dissociation of GDP from Galpha(i1) does not necessarily lead to immediate binding of GTP to Galpha(i1) in some cases. These effects of detergents on G-proteins must be taken into account in G-protein experiments.

Optimisation of saponin extraction conditions with Camellia sinensis var. assamica seed and its application for a natural detergent.

PubMed

Gong, Wanying; Huang, Yewei; Ji, Aibing; Peng, Wenshu; Liu, Cong; Zeng, Yin; Yang, Ruijuan; Yan, Liang; Wang, Xuanjun; Sheng, Jun

2018-04-01

Camellia sinensis var. assamica seed cake (a by-product of tea-seed oil) is an abundant resource with poor utilisation. C. sinensis var. assamica seed saponin (CSS) is one kind of non-ionic surfactant. In this study, the CSS extraction conditions were optimised by response surface methodology (RSM) and then the CSS detergent was developed. Additionally, the safety and decontamination ability of the developed detergent were evaluated. The optimised extraction conditions were including the extracting temperature of 40.04 °C, extraction time of 4.97 h, ethanol concentration of 64.11% and liquid-solid ratio of 14.57:1 mL g -1 . The formula of the CSS detergent was as follows: 20% crude CSS, 0.3% oxidised tea polyphenols (OTPs), 0.2% nisin, 0.3% sodium dehydroacetate, 0.7% sodium alginate and 0.5% sodium polyacrylate. The LD 50 of the CSS detergent exceeds 14 g kg -1 in mice, indicating the detergent was non-toxic. Both of the emulsifying and the pesticide residues removal abilities of the CSS detergent were significantly stronger than the commercial detergent. A natural tea seed saponin detergent with good safety and decontamination ability was successfully developed. This can make better use of the tea seed cake, thereby creating added value in the tea seed oil industry. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Impact of Surfactants on Skin Penetration of Dexpanthenol.

PubMed

Laffleur, Flavia; Pschick, Stefan; Barthelmes, Jan; Hauptstein, Sabine; Bernkop-Schnurch, Andreas

2018-01-01

It was the aim of this study to evaluate the impact of nonionic and ionic surfactants on skin penetration of dexpanthenol. The relative potency of three surfactants (two nonionic and one ionic) as enhancers in the permeability of a series of compounds was investigated. The influence of the enhancers was also studied. For this purpose, porcine abdominal skin was prepared and mounted on Franz diffusion cells, while different mixtures of Dexpanthenol containing Tween®85, SDS and Span®80 in concentrations of 0.5%, 1%, 2%, 5% (m/V) were evaluated in terms of their permeation enhancing effect. The amount of permeated drug was determined via HPLC analysis. Moreover, the cytotoxicity and skin irritating effect of the compounds were tested on Caco-2 cells. The cytotoxicity profile of Dexpanthenol showed no toxicity to the cells over 1 and 3 h of incubation. The permeation was evaluated over a time period of 180 min, whereas a ranking of SDS> Span>Tween could be determined as permeation enhancer. Taking these findings into consideration, concentration of 1% (w/w) surfactant showed the most promising results. The increase in flux based on low concentrations of enhancer was ascribed to their ability to reduce skin´s barrier and improve drug permeation. The results showed that the nature of enhancer greatly impacts cutaneous barrier impairment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Foam Properties and Detergent Abilities of the Saponins from Camellia oleifera

PubMed Central

Chen, Yu-Fen; Yang, Chao-Hsun; Chang, Ming-Shiang; Ciou, Yong-Ping; Huang, Yu-Chun

2010-01-01

The defatted seed meal of Camellia oleifera has been used as a natural detergent and its extract is commercially utilized as a foam-stabilizing and emulsifying agent. The goal of this study was to investigate the foam properties and detergent ability of the saponins from the defatted seed meal of C. oleifera. The crude saponin content in the defatted seed meal of C. oleifera was 8.34 and the total saponins content in the crude saponins extract was 39.5% (w/w). The foaming power of the 0.5 crude saponins extract solution from defatted seed meal of C. oleifera was 37.1 of 0.5 SLS solution and 51.3% to that of 0.5% Tween 80 solution. The R5 value of 86.0% represents good foam stability of the crude saponins extracted from the defatted seed meal of the plant. With the reduction of water surface tension from 72 mN/m to 50.0 mN/m, the 0.5% crude saponins extract solution has wetting ability. The sebum-removal experiment indicated that the crude saponins extract has moderate detergency. The detergent abilities of the saponins from C. oleifera and Sapindus mukorossi were also compared. PMID:21151446

Membrane solubilisation and reconstitution by octylglucoside: comparison of synthetic lipid and natural lipid extract by isothermal titration calorimetry.

PubMed

Krylova, Oxana O; Jahnke, Nadin; Keller, Sandro

2010-08-01

We have studied the solubilisation and reconstitution of lipid membranes composed of either synthetic phosphatidylcholine or Escherichia. coli polar lipid extract by the non-ionic detergent octylglucoside. For both lipid systems, composition-dependent transformations of unilamellar vesicles into micelles or vice versa were followed by high-sensitivity isothermal titration calorimetry. Data obtained over a range of detergent and lipid concentrations could be rationalised in terms of a three-stage phase separation model involving bilayer, bilayer/micelle coexistence, and micellar ranges, yielding the detergent/lipid phase diagrams and the bilayer-to-micelle partition coefficients of both detergent and lipid. The most notable difference between the lipids investigated was a substantial widening of the bilayer/micelle coexistence range for E. coli lipid, which was due to an increased preference of the detergent and a decreased affinity of the lipid for the micellar phase as compared with the bilayer phase. These effects on the bilayer-to-micelle partition coefficients could be explained by the high proportion in E. coli membranes of lipids possessing negative spontaneous curvature, which hampers both their transfer into strongly curved micellar structures as well as the insertion of detergent into condensed bilayers.

Sublethal detergent concentrations increase metabolization of recalcitrant polyphosphonates by the cyanobacterium Spirulina platensis.

PubMed

Forlani, Giuseppe; Bertazzini, Michele; Giberti, Samuele; Wieczorek, Dorota; Kafarski, Paweł; Lipok, Jacek

2013-05-01

As a consequence of increasing industrial applications, thousand tons of polyphosphonates are introduced every year into the environment. The inherent stability of the C-P bond results in a prolonged half-life. Moreover, low uptake rates limit further their microbial metabolization. To assess whether low detergent concentrations were able to increase polyphosphonate utilization by the cyanobacterium Spirulina platensis, tolerance limits to the exposure to various detergents were determined by measuring the growth rate in the presence of graded levels below the critical micellar concentration. Then, the amount of hexamethylenediamine-N,N,N',N'-tetrakis(methylphosphonic acid) that is metabolized in the absence or in the presence of sublethal detergent concentrations was quantified by (31)P NMR analysis on either P-starved or P-fed cyanobacterial cultures. The strain tolerated the presence of detergents in the order: nonionic > anionic > cationic. When added to the culture medium at the highest concentrations showing no detrimental effects upon cell viability, detergents either improved or decreased polyphosphonate utilization, the anionic sodium dodecyl sulfate being the most beneficial. Metabolization was not lower in P-fed cells--a result that strengthens the possibility of using, in the future, this strain for bioremediation purposes.

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

A novel preparation method for silicone oil nanoemulsions and its application for coating hair with silicone

PubMed Central

Hu, Zhenhua; Liao, Meiling; Chen, Yinghui; Cai, Yunpeng; Meng, Lele; Liu, Yajun; Lv, Nan; Liu, Zhenguo; Yuan, Weien

2012-01-01

Background Silicone oil, as a major component in conditioner, is beneficial in the moisture preservation and lubrication of hair. However, it is difficult for silicone oil to directly absorb on the hair surface because of its hydrophobicity. Stable nanoemulsions containing silicone oil may present as a potential solution to this problem. Methods Silicone oil nanoemulsions were prepared using the oil-in-water method with nonionic surfactants. Emulsion particle size and distribution were characterized by scanning electron microscopy. The kinetic stability of this nanoemulsion system was investigated under accelerated stability tests and long-term storage. The effect of silicone oil deposition on hair was examined by analyzing the element of hair after treatment of silicone oil nanoemulsions. Results Nonionic surfactants such as Span 80 and Tween 80 are suitable emulsifiers to prepare oil-in-water nanoemulsions that are both thermodynamically stable and can enhance the absorption of silicone oil on hair surface. Conclusion The silicone oil-in-water nanoemulsions containing nonionic surfactants present as a promising solution to improve the silicone oil deposition on the hair surface for hair care applications. PMID:23166436

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.

Emulsifying properties of legume proteins compared to β-lactoglobulin and Tween 20 and the volatile release from oil-in-water emulsions.

PubMed

Benjamin, O; Silcock, P; Beauchamp, J; Buettner, A; Everett, D W

2014-10-01

The emulsifying properties of plant legume protein isolates (soy, pea, and lupin) were compared to a milk whey protein, β-lactoglobulin (β-lg), and a nonionic surfactant (Tween 20). The protein fractional composition was characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The following emulsion properties were measured: particle diameter, shear surface ζ-potential, interfacial tension (IT), and creaming velocity. The effect of protein preheat treatment (90 °C for 10 min) on the emulsifying behavior and the release of selected volatile organic compounds (VOCs) from emulsions under oral conditions was also investigated in real time using proton transfer reaction-mass spectrometry. The legume proteins showed comparable results to β-lg and Tween 20, forming stable, negatively charged emulsions with particle diameter d3,2 < 0.4 μm, and maintained stability over 50 d. The relatively lower stability of lupin emulsions was significantly correlated with the low protein surface hydrophobicity and IT of the emulsion. After heating the proteins, the droplet size of pea and lupin emulsions decreased. The VOC release profile was similar between the protein-stabilized emulsions, and greater retention was observed for Tween 20-stabilized emulsions. This study demonstrates the potential application of legume proteins as alternative emulsifiers to milk proteins in emulsion products. © 2014 Institute of Food Technologists®

Neem oil (Azadirachta indica) nanoemulsion--a potent larvicidal agent against Culex quinquefasciatus.

PubMed

Anjali, C H; Sharma, Yamini; Mukherjee, Amitava; Chandrasekaran, Natarajan

2012-02-01

Nanoemulsion composed of neem oil and non-ionic surfactant Tween 20, with a mean droplet size ranging from 31.03 to 251.43 nm, was formulated for various concentrations of the oil and surfactant. The larvicidal effect of the formulated neem oil nanoemulsion was checked against Culex quinquefasciatus. O/W emulsion was prepared using neem oil, Tween 20 and water. Nanoemulsion of 31.03 nm size was obtained at a 1:3 ratio of oil and surfactant, and it was found to be stable. The larger droplet size (251.43 nm) shifted to a smaller size of 31.03 nm with increase in the concentration of Tween 20. The viscosity of the nanoemulsion increased with increasing concentration of Tween 20. The lethal concentration (LC50) of the nanoemulsion against Cx. quinquefasciatus was checked for 1:0.30, 1:1.5 and 1:3 ratios of oil and surfactant respectively. The LC50 decreased with droplet size. The LC50 for the ratio 1:3 nanoemulsions was 11.75 mg L(-1). The formulated nanoemulsion of 31.03 nm size was found to be an effective larvicidal agent. This is the first time that a neem oil nanoemulsion of this droplet size has been reported. It may be a good choice as a potent and selective larvicide for Cx. quinquefasciatus. Copyright © 2011 Society of Chemical Industry.

The Effect of Detergents on the Morphology and Immunomodulatory Activity of Malassezia furfur

PubMed Central

Kim, Su-Han; Ko, Hyun-Chang; Kwon, Kyung-Sool; Oh, Chang-Keun

2009-01-01

Background Several workers have found that Malassezia are capable of suppressing cytokine release and downregulating the phagocytic function of monocytes. But lipid-depleted Malassezia furfur (M. furfur) extracts have also been shown to induce increased production of TNF-α, IL-6 and IL-1β in monocytes. We thought that the detergents in shampoos or soaps could change the composition of the lipid in the M. furfur cell wall. Objective We studied whether detergents affect the morphology of M. furfur and if the inflammatory cytokine profiles change in the monocytes treated with detergent-treated M. furfur. Methods Commonly used detergents such as sodium lauryl sulfate, ammonium lauryl sulfate and tween-80 were respectively added to the modified Leeming-Notman's media. M. furfur was cultivated in each media (detergent-added or untreated). Thereafter, the surface morphology of the yeast was evaluated by scanning and transmission electron microscopy. The cytokine profiles of monocytes, which were treated by M. furfur with or without detergents, were also evaluated. Results The detergent-treated M. furfur were similar to the lipid-extracted form of M. furfur on the electron microscopic study, with a recessed, withered surface and with thinner and rather electron transparent cell walls than the detergent-untreated M. furfur. The levels of TNF-α were higher in monocytes treated with detergent-treated Malassezia than that in the monocytes treated with the detergent-untreated Malassezia (p<0.05). Conclusion According to the findings in this study, it could be inferred that the detergents in shampoos or soaps affect the lipid layers of the Malassezia cell wall and these lipid-extracted Malassezia induce or aggravate some inflammatory conditions. But to correlate the relationship between detergents and Malassezia-associated diseases, in vivo experiments that will focus on short-term contact with detergents in real life conditions should be done. PMID:20523770

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

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.

Preparation of Nonionic Vesicles Using the Supercritical Carbon Dioxide Reverse Phase Evaporation Method and Analysis of Their Solution Properties.

PubMed

Yamaguchi, Shunsuke; Tsuchiya, Koji; Sakai, Kenichi; Abe, Masahiko; Sakai, Hideki

2016-01-01

We have previously reported a new preparation method for liposomes using supercritical carbon dioxide (scCO2) as a solvent, referred to as the supercritical carbon dioxide reverse phase evaporation (scRPE) method. In our previous work, addition of ethanol to scCO2 as a co-solvent was needed, because lipid molecules had to be dissolved in scCO2 to form liposomes. In this new study, niosomes (nonionic surfactant vesicles) were prepared from various nonionic surfactants using the scRPE method. Among the nonionic surfactants tested were polyoxyethylene (6) stearylether (C18EO6), polyoxyethylene (5) phytosterolether (BPS-5), polyoxyethylene (6) sorbitan stearylester (TS-106V), and polyoxyethylene (4) sorbitan stearylester (Tween 61). All these surfactants have hydrophilic-lipophilic balance values (HLBs) around 9.5 to 9.9, and they can all form niosomes using the scRPE method even in the absence of ethanol. The high solubility of these surfactants in scCO2 was shown to be an important factor in yielding niosomes without ethanol addition. The niosomes prepared with the scRPE method had higher trapping efficiencies than those prepared using the conventional Bangham method, since the scRPE method gives a large number of unilamellar vesicles while the Bangham method gives multilamellar vesicles. Polyoxyethylene-type nonionic surfactants with HLB values from 9.5 to 9.9 were shown to be optimal for the preparation of niosomes with the scRPE method.

Simple size-controlled synthesis of Au nanoparticles and their size-dependent catalytic activity

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

Suchomel, Petr; Kvitek, Libor; Prucek, Robert

The controlled preparation of Au nanoparticles (NPs) in the size range of 6 to 22 nm is explored in this study. The Au NPs were prepared by the reduction of tetrachloroauric acid using maltose in the presence of nonionic surfactant Tween 80 at various concentrations to control the size of the resulting Au NPs. With increasing concentration of Tween 80 a decrease in the size of produced Au NPs was observed, along with a significant decrease in their size distribution. The size-dependent catalytic activity of the synthesized Au NPs was tested in the reduction of 4-nitrophenol with sodium borohydride, resultingmore » in increasing catalytic activity with decreasing size of the prepared nanoparticles. Eley-Rideal catalytic mechanism emerges as the more probable, in contrary to the Langmuir-Hinshelwood mechanism reported for other noble metal nanocatalysts.« less

Simple size-controlled synthesis of Au nanoparticles and their size-dependent catalytic activity

DOE PAGES

Suchomel, Petr; Kvitek, Libor; Prucek, Robert; ...

2018-03-15

The controlled preparation of Au nanoparticles (NPs) in the size range of 6 to 22 nm is explored in this study. The Au NPs were prepared by the reduction of tetrachloroauric acid using maltose in the presence of nonionic surfactant Tween 80 at various concentrations to control the size of the resulting Au NPs. With increasing concentration of Tween 80 a decrease in the size of produced Au NPs was observed, along with a significant decrease in their size distribution. The size-dependent catalytic activity of the synthesized Au NPs was tested in the reduction of 4-nitrophenol with sodium borohydride, resultingmore » in increasing catalytic activity with decreasing size of the prepared nanoparticles. Eley-Rideal catalytic mechanism emerges as the more probable, in contrary to the Langmuir-Hinshelwood mechanism reported for other noble metal nanocatalysts.« less

Neem oil nanoemulsions: characterisation and antioxidant activity.

PubMed

Rinaldi, Federica; Hanieh, Patrizia Nadia; Longhi, Catia; Carradori, Simone; Secci, Daniela; Zengin, Gokhan; Ammendolia, Maria Grazia; Mattia, Elena; Del Favero, Elena; Marianecci, Carlotta; Carafa, Maria

2017-12-01

The aim of the present work is to develop nanoemulsions (NEs), nanosized emulsions, manufactured for improving the delivery of active pharmaceutical ingredients. In particular, nanoemulsions composed of Neem seed oil, contain rich bioactive components, and Tween 20 as nonionic surfactant were prepared. A mean droplet size ranging from 10 to 100 nm was obtained by modulating the oil/surfactant ratio. Physicochemical characterisation was carried out evaluating size, ζ-potential, microviscosity, polarity and turbidity of the external shell and morphology, along with stability in simulated cerebrospinal fluid (CSF), activity of Neem oil alone and in NEs, HEp-2 cell interaction and cytotoxicity studies. This study confirms the formation of NEs by Tween 20 and Neem oil at different weight ratios with small and homogenous dimensions. The antioxidant activity of Neem oil alone and in NEs was comparable, whereas its cytotoxicity was strongly reduced when loaded in NEs after interaction with HEp-2 cells.

Optimisation of the enzyme-based determination of hydrogen peroxide using the quartz crystal microbalance.

PubMed

Martin, S P; Lynch, J M; Reddy, S M

2002-09-01

The benzidines, 3,3'-diaminobenzidine (DAB), 3,3'-dimethoxybenzidine (DMOB) and 3,3',5,5'-tetramethylbenzidine (TMB) were enzymatically oxidised to detect hydrogen peroxide, using the quartz crystal. The oxidised product mainly remains in suspension, resulting in a limited quartz sensor signal. We have used two non-ionic surfactants, Tween 80 and Triton X-100 to interact with the oxidised amphiphilic products to increase their solubility and surface activity, and their ability to adsorb to the crystal surface. Tween 80 exhibits optimised response effects for DAB, DMOB and TMB at 0.012, 0.005, and 0.002% (v/v), respectively, whereas Triton X-100 is optimum at 0.1, 0.2, and 0.006% (v/v), respectively. As a result, we have improved the quartz crystal sensor sensitivity to peroxide. The use of Triton X-100 gave an improved response time.

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.

Concentrating membrane proteins using ultrafiltration without concentrating detergents.

PubMed

Feroz, Hasin; Vandervelden, Craig; Ikwuagwu, Bon; Ferlez, Bryan; Baker, Carol S; Lugar, Daniel J; Grzelakowski, Mariusz; Golbeck, John H; Zydney, Andrew L; Kumar, Manish

2016-10-01

Membrane proteins (MPs) are of rapidly growing interest in the design of pharmaceutical products, novel sensors, and synthetic membranes. Ultrafiltration (UF) using commercially available centrifugal concentrators is typically employed for laboratory-scale concentration of low-yield MPs, but its use is accompanied by a concomitant increase in concentration of detergent micelles. We present a detailed analysis of the hydrodynamic processes that control detergent passage during ultrafiltration of MPs and propose methods to optimize detergent passage during protein concentration in larger-scale membrane processes. Experiments were conducted using nonionic detergents, octyl-β-D glucoside (OG), and decyl-β-D maltoside (DM) with the bacterial water channel protein, Aquaporin Z (AqpZ) and the light driven chloride pump, halorhodopsin (HR), respectively. The observed sieving coefficient (So ), a measure of detergent passage, was evaluated in both stirred cell and centrifugal systems. So for DM and OG increased with increasing filtrate flux and decreasing shear rates in the stirred cell, that is, with increasing concentration polarization (CP). Similar effects were observed during filtration of MP-detergent (MPD) micelles. However, lower transmission was observed in the centrifugal system for both detergent and MPD systems. This is attributed to free convection-induced shear and hence reduced CP along the membrane surface during centrifugal UF. Thus to concentrate MPs without retention of detergent, design of UF systems that promote CP is required. Biotechnol. Bioeng. 2016;113: 2122-2130. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Effects of ionic and nonionic surfactants on milk shell wettability during co-spray-drying of whole milk particles.

PubMed

Lallbeeharry, P; Tian, Y; Fu, N; Wu, W D; Woo, M W; Selomulya, C; Chen, X D

2014-09-01

Mixing surfactants with whole milk feed before spray drying could be a commercially favorable approach to produce instant whole milk powders in a single step. Pure whole milk powders obtained directly from spray drying often have a high surface fat coverage (up to 98%), rendering them less stable during storage and less wettable upon reconstitution. Dairy industries often coat these powders with lecithin, a food-grade surfactant, in a secondary fluidized-bed drying stage to produce instant powders. This study investigated the changes in wetting behavior on the surface of a whole milk particle caused by the addition of surfactants before drying. Fresh whole milk was mixed with 0.1% (wt/wt) Tween 80 or 1% (wt/wt) lecithin (total solids), and the wetting behavior of the shell formed by each sample was captured using a single-droplet drying device at intermediate drying stages as the shell was forming. The addition of surfactants improved shell wettability from the beginning of shell formation, producing more wettable milk particles after drying. The increase in surfactant loading by 10 times reduced the wetting time from around 30s to <5s. At the same loading of 1% (wt/wt; total solids), milk particles with Tween 80 were much more wettable than those with lecithin (<5s compared with >30s). We proposed that Tween 80 could adsorb at the oil-water interface of fat globules, making the surface fat more wettable, whereas lecithin tends to combine with milk proteins to form a complex, which then competes for the air-water surface with fat globules. Spray-drying experiments confirmed the greatly improved wettability of whole milk powders by the addition of either 0.1% (wt/wt) Tween 80 or 1% (wt/wt) lecithin; wetting time was reduced from 35±4s to <15s. To the best of our knowledge, this is the first time that a dynamic droplet drying system has been used to elucidate the complex interactions between ionic or nonionic surfactants and milk components (both proteins and fat), as well as the resultant effect on the development of milk particle functionality during drying. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

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.

Adsorption at air-water and oil-water interfaces and self-assembly in aqueous solution of ethoxylated polysorbate nonionic surfactants.

PubMed

Penfold, Jeffrey; Thomas, Robert K; Li, Peixun X; Petkov, Jordan T; Tucker, Ian; Webster, John R P; Terry, Ann E

2015-03-17

The Tween nonionic surfactants are ethoxylated sorbitan esters, which have 20 ethylene oxide groups attached to the sorbitan headgroup and a single alkyl chain, lauryl, palmityl, stearyl, or oleyl. They are an important class of surfactants that are extensively used in emulsion and foam stabilization and in applications associated with foods, cosmetics and pharmaceuticals. A range of ethoxylated polysorbate surfactants, with differing degrees of ethoxylation from 3 to 50 ethylene oxide groups, have been synthesized and characterized by neutron reflection, small-angle neutron scattering, and surface tension. In conjunction with different alkyl chain groups, this provides the opportunity to modify their surface properties, their self-assembly in solution, and their interaction with macromolecules, such as proteins. Adsorption at the air-water and oil-water interfaces and solution self-assembly of the range of ethoxylated polysorbate surfactants synthesized are presented and discussed.

Interaction between water-soluble rhodium complex RhCl(CO)(TPPTS)₂ and surfactants probed by spectroscopic methods.

PubMed

Zhou, Li-Mei; Guo, Cai-Hong; Fu, Hai-Yan; Jiang, Xiao-Hui; Chen, Hua; Li, Rui-Xiang; Li, Xian-Jun

2012-07-01

The interactions of rhodium complex RhCl(CO)(TPPTS)(2) [TPPTS=P(m-C(6)H(4)SO(3)Na)(3)] with cationic, nonionic, and anionic surfactants have been investigated by UV-vis, fluorescence and (1)H NMR measurements. The presence of four different species of RhCl(CO)(TPPTS)(2) in cationic cetyltrimethylammonium (CTAB) solution has been demonstrated: free rhodium complex, rhodium complex bound to CTAB monomer, rhodium complex bound to CTAB premicelles, rhodium complex bound to CTAB micelles. The spectroscopy data show that RhCl(CO)(TPPTS)(2) can adsorb on the interface of cationic CTAB micelles by strong electrostatic attraction, weakly bind to the nonionic polyoxyethylene (20) sorbitan monolaurate (Tween 20) micelles by hydrophobic interaction, and does not interact with anion sodium dodecyl sulfate (SDS) micelles due to the strong electrostatic repulsion. Copyright © 2012 Elsevier B.V. All rights reserved.

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

Comparison of the orogenic displacement of sodium caseinate with the caseins from the air-water interface by nonionic surfactants.

PubMed

Woodward, N C; Gunning, A P; Mackie, A R; Wilde, P J; Morris, V J

2009-06-16

Displacement of sodium caseinate from the air-water interface by nonionic surfactants Tween 20 and Tween 60 was observed by atomic force microscopy (AFM). The interfacial structure was sampled by Langmuir-Blodgett deposition onto freshly cleaved mica substrates. Protein displacement occurred through an orogenic mechanism: it involved the nucleation and growth of surfactant domains within the protein network, followed by failure of the protein network. The surface pressure at which failure of the protein network occurred was essentially independent of the type of surfactant. The major component of sodium caseinate is beta-casein, and previous studies at the air-water interface have shown that beta-casein networks are weak, failing at surface pressures below that observed for sodium caseinate. The other components of sodium caseinate are alpha(s)- and kappa-caseins. Studies of the displacement of alpha(s)-caseins from air-water interfaces show that these proteins also form weak networks that fail at surface pressures below that observed for sodium caseinate. However, kappa-casein was found to form strong networks that resisted displacement and failed at surface pressures comparable to those observed for sodium caseinate. The AFM images of the displacement suggest that, despite kappa-casein being a minor component, it dominates the failure of sodium caseinate networks: alpha(s)-casein and beta-casein are preferentially desorbed at lower surface pressures, allowing the residual kappa-casein to control the breakdown of the sodium caseinate network at higher surface pressures.

Assessment of alkaline cholesterol oxidase purified from Rhodococcus sp. PKPD-CL for its halo tolerance, detergent and organic solvent stability.

PubMed

Kasabe, Pramod J; Mali, Geetanjali T; Dandge, Padma B

2015-12-01

The novel bacterium, Rhodococcus sp. PKPD-CL was isolated and identified from the 'Chilika Lake' located at Odisha state of India, which is a largest brackish water habitat in Asia. Rhodococcus sp. PKPD-CL produces extracellular halo tolerant, detergent and organic solvent stable alkaline cholesterol oxidase. It has apparent molecular weight of 60 kDa and was purified 59 fold by using 60% saturated ammonium sulfate fractionation, anion exchange followed by size exclusion chromatographic techniques with 37% recovery. It showed substrate specificity for 3β-hydroxysteroids with Km of 1.1 × 10(-4)M for cholesterol. The pH, 8.0 and the temperature, 37 °C were required for its optimum activity. Enzyme is considerably stable at pH 6.0-8.5 and temperature up to 50 °C. At 4 and 30 °C it maintained its 100% activity up to 60 days. The isoelectric point of the enzyme was 9.5. It showed 80% residual activity with 20% NaCl (3.42 M) and 83% relative activity with 12% NaCl (2.05 M) concentration. The metal ions like Zn(2+), Cu(2+), Ag+, Fe(3+), Ba(2+) inhibited the enzyme activity >60% while Hg(2+) served a potent inhibitor whereas Mg(2+) found to be a good enhancer for it. The enzyme was stable in presence of chemical reagents (NaN3, EDTA), detergents (Tween-80, Tween-20, Triton X-100, sodium cholate) and various organic solvents (isopropanol, ethanol, benzene, chloroform, methanol, toluene, ethyl acetate, butanol and dimethylsulfoxide). Such a multi stress tolerant and versatile enzyme produced by Rhodococcus sp. PKPD-CL may serve as a good choice for industrial applications. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Characterization of proteases from Planomicrobium sp. L-2 isolated from the gastrointestinal tract of Octopus variabilis (Sasaki)

NASA Astrophysics Data System (ADS)

Jin, Yulan; Wang, Yurong; Xiao, Lin; Lin, Xiukun

2016-05-01

A crude protease produced from Planomicrobium sp. L-2 is described, and its effectiveness as an additive in liquid detergent evaluated. We isolate the protease-producing Planomicrobium sp. L-2 from the gastrointestinal tract of Octopus variabilis. At least three caseinolytic protease clear bands were observed in zymogram analysis. The crude alkaline protease was highly tolerant of a pH range from 7.0 to 9.0, and temperatures to 50°C after incubation for 1 h. Proteolytic enzymes were stable towards three surfactants (5% Tween 80, 1% Triton X-100 and 0.05% SDS) and an oxidizing agent (1% hydrogen peroxide), in addition to being highly stable and compatible with popular commercial laundry powered detergent brands available in China. Our study demonstrates the potential these proteases have for development into novel classes of detergent additive. This study also suggests that the gastrointestinal tract of Octopus variabilis may be a rich source of commercially valuable strains of enzyme.

Utilization of acid pre-treated coconut dregs as a substrate for production of detergent compatible lipase by Bacillus stratosphericus.

PubMed

Mohd Zin, Nur Bainun; Mohamad Yusof, Busyra; Oslan, Siti Nurbaya; Wasoh, Helmi; Tan, Joo Shun; Ariff, Arbakariya B; Halim, Murni

2017-12-01

In recent years, many efforts have been directed to explore the methods to reduce the production costs of industrial lipase by improving the yield and the use of low-cost agricultural wastes. Coconut dregs, which is a lignocellulosic by-product from coconut oil and milk processing plants, is rich in cellulose (36%) and crude fat (9%). A newly isolated Bacillus stratosphericus has been demonstrated to perform cellulose hydrolysis on coconut dregs producing fermentable sugars. The highest extracellular lipase activity of 140 U/mL has been achieved in submerged fermentation with acid pre-treated coconut dregs. The lipase was found to be active over a wide range of temperatures and pHs. The activity of lipase can be generally increased by the presence of detergent ingredients such as Tween-80, cetyltrimethylammonium bromide, hydrogen peroxide and phosphate per sulphate. The great compatibility of lipase in commercial detergents has also underlined its potential as an additive ingredient in biodetergent formulations.

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.

Robust cross-links in molluscan adhesive gels: Testing for contributions from hydrophobic and electrostatic interactions

PubMed Central

Smith, A.M.; Robinson, T. M.; Salt, M. D.; Hamilton, K. S.; Silvia, B. E.; Blasiak, R.

2009-01-01

The cross-linking interactions that provide cohesive strength to molluscan adhesive gels were investigated. Metal-based interactions have been shown to play an important role in the glue of the slug Arion subfuscus (Draparnaud), but other types of interactions may also contribute to the glue's strength and their role has not been investigated. This study shows that treatments that normally disrupt hydrophobic or electrostatic interactions have little to no effect on the slug glue. High salt concentrations and non-ionic detergent do not affect the solubility of the proteins in the glue or the ability of the glue proteins to stiffen gels. In contrast, metal chelation markedly disrupts the gel. Experiments with gel filtration chromatography identify a 40 kDa protein that is a central component of the cross-links in the glue. This 40 kDa protein forms robust macromolecular aggregations that are stable even in the presence of high concentrations of salt, non-ionic detergent, urea or metal chelators. Metal chelation during glue secretion, however, may block some of these cross-links. Such robust, non-specific interactions in an aqueous environment are highly unusual for hydrogels and reflect an intriguing cross-linking mechanism. PMID:18952190

Robust cross-links in molluscan adhesive gels: testing for contributions from hydrophobic and electrostatic interactions.

PubMed

Smith, A M; Robinson, T M; Salt, M D; Hamilton, K S; Silvia, B E; Blasiak, R

2009-02-01

The cross-linking interactions that provide cohesive strength to molluscan adhesive gels were investigated. Metal-based interactions have been shown to play an important role in the glue of the slug Arion subfuscus (Draparnaud), but other types of interactions may also contribute to the glue's strength and their role has not been investigated. This study shows that treatments that normally disrupt hydrophobic or electrostatic interactions have little to no effect on the slug glue. High salt concentrations and non-ionic detergent do not affect the solubility of the proteins in the glue or the ability of the glue proteins to stiffen gels. In contrast, metal chelation markedly disrupts the gel. Experiments with gel filtration chromatography identify a 40 kDa protein that is a central component of the cross-links in the glue. This 40 kDa protein forms robust macromolecular aggregations that are stable even in the presence of high concentrations of salt, non-ionic detergent, urea or metal chelators. Metal chelation during glue secretion, however, may block some of these cross-links. Such robust, non-specific interactions in an aqueous environment are highly unusual for hydrogels and reflect an intriguing cross-linking mechanism.

An impedimetric chemical sensor for determination of detergents residues.

PubMed

Bratov, Andrey; Abramova, Natalia; Ipatov, Andrey; Merlos, Angel

2013-03-15

A new impedimetric sensor based on an interdigitated electrode array with electrode digits located at the bottom of microcapillaries formed in silicon dioxide is presented. Microcapillaries are opened at the top, so that in contact with an electrolyte solution the ac current flows close to the surface of the capillary wall from one electrode to another and is significantly affected by changes in the surface conductance at the SiO2/electrolyte interface. Adsorption of detergents on the sensor surface affects the charge distribution in the electrical double layer and thus the surface conductance. These changes are registered by measuring impedance. Effect of surface adsorption of ionic and non-ionic surfactants on the sensor impedance is studied. The sensor is shown to be able to measure commercial detergents residues in a tap water starting from 5 ppm even in solutions with high electrolyte conductivity. Copyright © 2012 Elsevier B.V. All rights reserved.

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.

Molecular organization and dynamics of micellar phase of polyelectrolyte-surfactant complexes: ESR spin probe study

NASA Astrophysics Data System (ADS)

Wasserman, A. M.; Kasaikin, V. A.; Zakharova, Yu. A.; Aliev, I. I.; Baranovsky, V. Yu.; Doseva, V.; Yasina, L. L.

2002-04-01

Molecular dynamics and organization of the micellar phase of complexes of linear polyelectrolytes with ionogenic and non-ionogenic surfactants was studied by the ESR spin probe method. Complexes of polyacrylic acid (PAA) and sodium polystyrenesulfonate (PSS) with alkyltrimethylammonium bromides (ATAB), as well as complexes of poly- N, N'-dimethyldiallylammonium chloride (PDACL) with sodium dodecylsulfate (SDS) were studied. The micellar phase of such complexes is highly organized molecular system, molecular ordering of which near the polymeric chain is much higher than in the 'center' of the micelle, it depends on the polymer-detergent interaction, flexibility of polymeric chain and length of carbonic part of the detergent molecule. Complexes of polymethacrylic acid (PMAA) with non-ionic detergent (dodecyl-substituted polyethyleneglycol), show that the local mobility of surfactant in such complexes is significantly lower than in 'free' micelles and depends on the number of micellar particles participating in formation of complexes.

Comparative evaluation of antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate and Tween as surfactants: an in vivo study.

PubMed

Venu, V; Prabhakar, A R; Basappa, N

2013-01-01

The aim of the study was to determine the antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate (SLS) and Tween as surfactants. It is a double-blind cross over the study, a total of 20 children within their mixed dentition period (7-13 year) having Streptococci mutans count more than 10(6) were selected for the main study. Three types of chlorhexidine containing dentifrices were used with a washout period of 1 week. Out of the three toothpastes, one was without surfactant and other two toothpastes contained SLS and Tween as surfactants respectively. 20 volunteers brushed for 1 min during the study day with their assigned toothpaste. Saliva samples were collected before brushing, immediately after brushing and 1, 3, 5, and 7 hand sent for microbial analysis. The culture carried out by inoculating saliva sample onto Mitis salivarius agar for selective isolation of S. mutans followed by counting of colony forming unit. Group I and III (Chlorhexidine and CHX + Tween) had shown statistically significant reduction in bacterial count until 7 h when compared to their baseline values ( P < 0.001). Group II toothpaste (CHX + SLS) had shown significant reduction in bacterial count until 3 h only. On inter group comparison, Group III had shown good amount of percentage reduction in bacterial count when compared to other groups. CHX + Tween toothpaste had shown statistically significant reduction in antibacterial activity and substantivity than other groups. These findings show chlorhexidine containing toothpaste with non-ionic surfactant will be able to maintain the antibacterial property and substantivity of chlorhexidine.

Characterisation of crude palm oil O/W emulsion produced with Tween 80 and potential in residual oil recovery of palm pressed mesocarp fibre

NASA Astrophysics Data System (ADS)

Ramly, N. H.; Zakaria, R.; Naim, M. N.

2016-06-01

Surfactant-assisted aqueous extraction has been proposed as a “green” alternative to hexane extraction for the recovery of oil from plant matters. An efficient aqueous surfactant extraction system usually use an extended type of ionic surfactant with the ability to produce Winsor type III microemulsion, reducing the interfacial tension (IFT) between plant oil and surfactant solution to an ultralow level (10-3 mN/m). However, the safe used of this surfactant in food processing is uncertain leading to non-food application of the recovered oil. In the present study, the potential of Tween 80, a commercial food-grade non-ionic surfactant, was evaluated in the recovery of residual oil from palm-pressed mesocarp. The emulsion produced between Tween 80 and crude palm oil (CPO) was characterised in terms of IFT, droplet size, viscosity and phase inversion temperature (PIT). The effect of surfactant concentration, electrolyte (NaCl) and temperature were studied to determine whether a Winsor Type III microemulsion can be produced. Results shows that although these parameters were able to reduce the IFT to very low values, Winsor type III microemulsion was not produced with this single surfactant. Emulsion of CPO and Tween 80 solution did not produce a PIT even after heating to 100°C indicating that middle phase emulsion was not able to be formed with increasing temperature. The highest percentage of oil extraction (38.84%) was obtained at the concentration above the critical micelle concentration (CMC) of Tween 80 and CPO, which was at 0.5 wt% Tween 80 with 6% NaCl, and temperature of 60°C. At this concentration, the IFT value is 0.253 mN/m with a droplet size of 4183.8 nm, and a viscosity of 7.38 cp.

Determination and residual characteristic of alkylphenols in household food detergents of Taiwan.

PubMed

Pan, Yi-Ping; Tsai, Shih-Wei

2009-07-01

The non-ionic surfactants are mostly composed of alkylphenols for the ingredients of synthetic food detergents. Due to the ability to mimic hormones, it has been noticed that the exposures of alkylphenols might cause a variety of adverse effects. To assess the associate risks from possible exposures, concentrations of alkylphenols, including 4-nonylphenol (4-NP), technical nonylphenol isomers (t-NP(S)), and 4-tert-octylphenol (4-t-OP), in household food detergents of Taiwan were determined. Gas chromatography with mass spectrometer (GC/MS) was used to analyze alkylphenols in samples. The Taguchi experimental design was utilized to study the possible factors that might affect the residual characteristics of alkylphenols from detergents on dishware and fruits. By the analysis of variance, the orders of importance of different parameters were determined. The results showed that the concentrations of alkylphenols in food detergents ranged from 1.71 x 10(-5) to 2.13 x 10(-3) (APs/detergent, mgg(-1)). For residual characteristics, the cleaning temperature was found to be the only significant factor that will affect the 4-t-OP left on the dishware, while the concentrations of detergents used will affect the left of t-NPs and 4-NP on dishware as well. On the other hand, the varieties of fruits, the concentrations of detergents, and the concentrations of alkylphenols were found to have significant effects for the t-NPs left on fruits. As for the exposure assessments, the maximum dose of APs exposures from the use of household food detergents in Taiwan was also estimated in the study.

Adsorption of calcitonin to glass.

PubMed

Law, S L; Shih, C L

1999-02-01

Surface adsorption of calcitonin on soda lime silica glass was investigated. An attempt was also made to examine the effect of additives on the inhibition of calcitonin adsorption. Results showed that the adsorption isotherms were of the Langmuir and Freundlich type, depending on pH. Less adsorption was found for calcitonin at pH 4.3. The addition of nonionic surfactants such as Pluronic F68 and Tween 80 to the calcitonin solutions demonstrated inhibition of absorption and reduction of adsorption rate. The addition of chlorobutanol also showed the effect of minimizing adsorption.

Ultrasound-assisted sol-gel synthesis of ZrO2.

PubMed

Guel, Marlene Lariza Andrade; Jiménez, Lourdes Díaz; Hernández, Dora Alicia Cortés

2017-03-01

Synthesis of tetragonal ZrO 2 by both conventional sol-gel and ultrasound-assisted sol-gel methods and using a non-ionic surfactant Tween-20, was performed. A porous microstructure composed of nanometric particles was observed. Tetragonal ZrO 2 was obtained using a low heat treatment temperature of powders, 500°C by both methods. A higher crystallinity and a shorter reaction time were observed when ultrasound was used in the sol-gel method due to the cavitation phenomenon. Copyright © 2016 Elsevier B.V. All rights reserved.

Tonoplast of Beta vulgaris L. contains detergent-resistant membrane microdomains.

PubMed

Ozolina, Natalia V; Nesterkina, Irina S; Kolesnikova, Ekaterina V; Salyaev, Ryurik K; Nurminsky, Vadim N; Rakevich, Alexander L; Martynovich, Evgueni F; Chernyshov, Michael Yu

2013-03-01

The experiments conducted on tonoplast of Beta vulgaris L. roots were performed to identify detergent-resistant lipid-protein microdomains (DRMs, interpreted as lipid rafts).The presence of DRMs can be found when dynamic clustering of sphingolipids, sterols, saturated fatty acids is registered, and the insolubility of these microdomains in nonionic detergents at low temperatures is proven. The elucidation of tonoplast microdomains has been based on results obtained with the aid of high-speed centrifuging in the sucrose gradient. The experiments have shown that tonoplast microdomains are rich in sphingolipids, free sterols and saturated fatty acids (such a lipid content is also typical of lipid-protein microdomains of other membranes), while only few phospholipids are present in tonoplast microdomains. The presence of microdomains has been confirmed by fluorescence and confocal microscopy using filipin and Laurdan as fluorescent probes. The experiments with Laurdan have shown that tonoplast microdomains are characterized by a high order compared to characteristics of the rest of the tonoplast. Thus, the presence of detergent-resistant lipid-protein microdomains in the tonoplast has been demonstrated.

Identification and Biochemical Evidence of a Medium-Chain-Length Polyhydroxyalkanoate Depolymerase in the Bdellovibrio bacteriovorus Predatory Hydrolytic Arsenal

PubMed Central

Martínez, Virginia; de la Peña, Fernando; García-Hidalgo, Javier; de la Mata, Isabel; García, José Luis

2012-01-01

The obligate predator Bdellovibrio bacteriovorus HD100 shows a large set of proteases and other hydrolases as part of its hydrolytic arsenal needed for its predatory life cycle. We present genetic and biochemical evidence that open reading frame (ORF) Bd3709 of B. bacteriovorus HD100 encodes a novel medium-chain-length polyhydroxyalkanoate (mcl-PHA) depolymerase (PhaZBd). The primary structure of PhaZBd suggests that this enzyme belongs to the α/β-hydrolase fold family and has a typical serine hydrolase catalytic triad (serine-histidine-aspartic acid) in agreement with other PHA depolymerases and lipases. PhaZBd has been extracellularly produced using different hypersecretor Tol-pal mutants of Escherichia coli and Pseudomonas putida as recombinant hosts. The recombinant PhaZBd has been characterized, and its biochemical properties have been compared to those of other PHA depolymerases. The enzyme behaves as a serine hydrolase that is inhibited by phenylmethylsulfonyl fluoride. It is also affected by the reducing agent dithiothreitol and nonionic detergents like Tween 80. PhaZBd is an endoexohydrolase that cleaves both large and small PHA molecules, producing mainly dimers but also monomers and trimers. The enzyme specifically degrades mcl-PHA and is inactive toward short-chain-length polyhydroxyalkanoates (scl-PHA) like polyhydroxybutyrate (PHB). These studies shed light on the potentiality of these predators as sources of new biocatalysts, such as an mcl-PHA depolymerase, for the production of enantiopure hydroxyalkanoic acids and oligomers as building blocks for the synthesis of biobased polymers. PMID:22706067

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

Removal of lead contaminated dusts from hard surfaces.

PubMed

Lewis, Roger D; Condoor, Sridhar; Batek, Joe; Ong, Kee Hean; Backer, Denis; Sterling, David; Siria, Jeff; Chen, John J; Ashley, Peter

2006-01-15

Government guidelines have widely recommended trisodium phosphate (TSP) or "lead-specific" cleaning detergents for removal of lead-contaminated dust (LCD) from hard surfaces, such as floors and window areas. The purpose of this study was to determine if low-phosphate, non-lead-specific cleaners could be used to efficiently remove LCD from 3 types of surfaces (vinyl flooring, wood, and wallpaper). Laboratory methods were developed and validated for simulating the doping, embedding, and sponge cleaning of the 3 surface types with 4 categories of cleaners: lead-specific detergents, nonionic cleaners, anionic cleaners, and trisodium phosphate (TSP). Vinyl flooring and wood were worn using artificial means. Materials were ashed, followed by ultrasound extraction, and anodic stripping voltammetry (ASV). One-way analysis of variance approach was used to evaluate the surface and detergent effects. Surface type was found to be a significant factor in removal of lead (p < 0.001). Vinyl flooring cleaned better than wallpaper by over 14% and wood cleaned better than wallpaper by 13%. There was no difference between the cleaning action of vinyl flooring and wood. No evidence was found to support the use of TSP or lead-specific detergents over all-purpose cleaning detergents for removal of lead-contaminated dusts. No-phosphate, non-lead-specific detergents are effective in sponge cleaning of lead-contaminated hard surfaces and childhood lead prevention programs should consider recommending all-purpose household detergents for removal of lead-contaminated dust after appropriate vacuuming.

Effect of ionic detergents, nonionic detergents, and chaotropic agents on polyphenol oxidase activity from dormant saffron (Crocus sativus L.) corms.

PubMed

Saeidian, Shahriar; Keyhani, Ezzatollah; Keyhani, Jacqueline

2007-05-02

Polyphenol oxidase (PPO; EC 1.14.18.1) catalyzes the hydroxylation of monophenols to o-diphenols (cresolase activity) and the oxidation of o-diphenols to o-quinones (catecholase activity), leading to browning in plants and produce. Further interest in the enzyme has been triggered by the active role that it plays in plant defense systems. PPO can be found in latent forms and is activated in vitro by various agents including urea, detergents, and proteases. The activation of PPO from several sources by sodium dodecyl sulfate (SDS) has been extensively investigated, but reports on the effect of other detergents or on the differential effect of detergents on each of PPO's activities are scarce. In addition, investigations on the enzyme in other plant parts besides fruits and vegetables are also scarce. Here, the effect of various detergents and chaotropic agents on PPO from dormant saffron (Crocus sativus L.) corm extract was investigated. SDS and sarkosyl activated the cresolase activity, while only SDS activated the catecholase activity. All other detergents tested, in milli- or micromolar concentrations, inhibited the cresolase activity but barely affected the catecholase activity. In contrast, urea and guanidine-HCl drastically inhibited the catecholase activity but moderately inhibited the cresolase activity. The same effects were obtained on the partially purified enzyme. Results identified a PPO, present in dormant corms, which was activated only by anionic detergents and was inhibited by other reputed activating agents such as urea. Results also emphasized the differences in structure and accessibility of the active sites for cresolase and catecholase activities.

Biochemical characterization of detergent-resistant membranes: a systematic approach

PubMed Central

Babiychuk, Eduard B.; Draeger, Annette

2006-01-01

Lateral segregation of cholesterol- and sphingomyelin-rich rafts and glycerophospholipid-containing non-raft microdomains has been proposed to play a role in a variety of biological processes. The most compelling evidence for membrane segregation is based on the observation that extraction with non-ionic detergents leads to solubilization of a subset of membrane components only. However, one decade later, a large body of inconsistent detergent-extraction data is threatening the very concept of membrane segregation. We have assessed the validity of the existing paradigms and we show the following. (i) The localization of a membrane component within a particular fraction of a sucrose gradient cannot be taken as a yardstick for its solubility: a variable localization of the DRMs (detergent-resistant membranes) in sucrose gradients is the result of complex associations between the membrane skeleton and the lipid bilayer. (ii) DRMs of variable composition can be generated by using a single detergent, the increasing concentration of which gradually extracts one protein/lipid after another. Therefore any extraction pattern obtained by a single concentration experiment is bound to be ‘investigator-specific’. It follows that comparison of DRMs obtained by different detergents in a single concentration experiment is prone to misinterpretations. (iii) Depletion of cholesterol has a graded effect on membrane solubility. (iv) Differences in detergent solubility of the members of the annexin protein family arise from their association with chemically different membrane compartments; however, these cannot be attributed to the ‘brick-like’ raft-building blocks of fixed size and chemical composition. Our findings demonstrate a need for critical re-evaluation of the accumulated detergent-extraction data. PMID:16608442

Biochemical characterization of detergent-resistant membranes: a systematic approach.

PubMed

Babiychuk, Eduard B; Draeger, Annette

2006-08-01

Lateral segregation of cholesterol- and sphingomyelin-rich rafts and glycerophospholipid-containing non-raft microdomains has been proposed to play a role in a variety of biological processes. The most compelling evidence for membrane segregation is based on the observation that extraction with non-ionic detergents leads to solubilization of a subset of membrane components only. However, one decade later, a large body of inconsistent detergent-extraction data is threatening the very concept of membrane segregation. We have assessed the validity of the existing paradigms and we show the following. (i) The localization of a membrane component within a particular fraction of a sucrose gradient cannot be taken as a yardstick for its solubility: a variable localization of the DRMs (detergent-resistant membranes) in sucrose gradients is the result of complex associations between the membrane skeleton and the lipid bilayer. (ii) DRMs of variable composition can be generated by using a single detergent, the increasing concentration of which gradually extracts one protein/lipid after another. Therefore any extraction pattern obtained by a single concentration experiment is bound to be 'investigator-specific'. It follows that comparison of DRMs obtained by different detergents in a single concentration experiment is prone to misinterpretations. (iii) Depletion of cholesterol has a graded effect on membrane solubility. (iv) Differences in detergent solubility of the members of the annexin protein family arise from their association with chemically different membrane compartments; however, these cannot be attributed to the 'brick-like' raft-building blocks of fixed size and chemical composition. Our findings demonstrate a need for critical re-evaluation of the accumulated detergent-extraction data.

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.

[In vitro evaluation of the gels properties prepared on Pluronic F-127 as vehicles for administration prolactin by injection].

PubMed

Karolewicz, Bozena; Pawlik-Gałczyńska, Anna; Pluta, Janusz; Ryszka, Florian

2011-01-01

The aim of this study was to prepare a thermoresponsive formulations, which are a carrier for proteins--prolactin administered directly into solid tumor and which obtain sol-gel transitions at physiological ranges of temperature. Prolactin (PRL) is a hormone that in vivo and in vitro exhibits antiangiogenic properties. Application of this protein in the proposed formulations can be particularly advantageous because of its relatively low stability and limited ability to transmembrane penetration. The paper prepared thermoresponsive carriers, based on nonionic polymer Pluronic F-127 with selected excipients such as dextran 7000, PEG 400, Tween 20 and Tween 80. The sol-gel transition temperature of the formulations was investigated and their physicochemical properties such as pH, density, osmotic pressure were studied. In the remainder of the work carried out tests of prolactin release from the proposed media. The results obtained indicate that a significant influence on the theological parameters obtained carriers and the availability of pharmaceutical composition of prolactin was developed formulation.

Enhanced gene delivery to the lung using biodegradable polyunsaturated cationic phosphatidylcholine-detergent conjugates.

PubMed

Pierrat, Philippe; Kereselidze, Dimitri; Lux, Marie; Lebeau, Luc; Pons, Françoise

2016-09-10

Lung diseases are among the more representative causes of mortality and morbidity worldwide and gene therapy is considered as a promising therapeutic approach for their treatment. However the design of efficient nucleic acid carriers for airway administration still is a challenge and there is a pressing need for new developments in this field. Herein, new synthetic DNA carriers based on the conjugation of a phospholipid and C12E4, a nonionic detergent, are developed. DNA complexes with phosphatidylcholine-detergent conjugates are administered in mouse airways, and transgene expression and inflammatory activity as an index of toxicity are investigated as a function of time, DNA dose, and presence of helper and stealth lipids. Introduction of a biodegradable linker between the phosphatidylcholine and detergent moieties significantly attenuates the severity of inflammatory response that characterizes cationic lipid-mediated gene transfer. Concurrent introduction of polyunsaturated fatty acid chains in the carrier scaffold improves transgene expression and further reduces airway inflammation. Finally, the biodegradable phosphatidylcholine-detergent conjugates favorably compare to GL67A, the gold standard for DNA delivery to the airway that is currently under clinical evaluation. Our findings indicate that the lipid formulations described herein may have great potential as nucleic acid carriers for gene therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Improvement of the solubilization of proteins in two-dimensional electrophoresis with immobilized pH gradients

PubMed Central

Rabilloud, Thierry; Adessi, C.; Giraudel, A.; Lunardi, J.

2007-01-01

Summary We have carried out the separation of sparingly-soluble (membrane and nuclear) proteins by high resolution two-dimensional electrophoresis. IEF with immobilized pH gradients leads to severe quantitative losses of proteins in the resulting 2-D map, although the resolution is usually kept high. We therefore tried to improve the solubility of proteins in this technique, by using denaturing cocktails containing various detergents and chaotropes. Best results were obtained by using a denaturing solution containing urea, thiourea, and detergents (both nonionic and zwitterionic). The usefulness of thiourea-containing denaturing mixtures are shown in this article on several models including microsomal and nuclear proteins and on tubulin, a protein highly prone to aggregation. PMID:9150907

[Efficient extraction of transmembrane proteins using ProteoExtract Transmembrane Protein Extraction Kit].

PubMed

Błachnio, Karina

2010-01-01

Detergents commonly used for solubilization of membrane proteins may be ionic or non-ionic. Exposing membrane proteins to detergents, however, can adversely affect their native structure, which can be a major hindrance for functional studies. This is especially true for proteins with multiple transmembrane domains. The ProteoExtract Transmembrane Protein Extraction Kit (TM-PEK), offered by Merck, provides a detergent-free novel reagents to enable the mild and efficient extraction of proteins containing seven transmembrane domains, such as GPCRs (G-Protein Coupled Receptors) e.g.: Frizzled-4 and CELSR-3, from mammalian cells. The fraction enriched in transmembrane proteins using TM-PEK is directly compatible with enzyme assays, non-denaturing gel electrophoresis, 1- and 2-D SDS-PAGE, MS analysis, Western blotting, immunoprecipitation and ELISA. Unlike many alternatives, TM-PEK extraction procedure does not require sonication, extended rigorous vortexing, ultracentrifugation, or incubation of samples at elevated temperatures--thus minimizing the risk of post-extraction degradation or modifications.

Detergent-dependent kinetics of truncated Plasmodium falciparum dihydroorotate dehydrogenase.

PubMed

Malmquist, Nicholas A; Baldwin, Jeffrey; Phillips, Margaret A

2007-04-27

The survival of the malaria parasite Plasmodium falciparum is dependent upon the de novo biosynthesis of pyrimidines. P. falciparum dihydroorotate dehydrogenase (PfDHODH) catalyzes the fourth step in this pathway in an FMN-dependent reaction. The full-length enzyme is associated with the inner mitochondrial membrane, where ubiquinone (CoQ) serves as the terminal electron acceptor. The lipophilic nature of the co-substrate suggests that electron transfer to CoQ occurs at the two-dimensional lipid-solution interface. Here we show that PfDHODH associates with liposomes even in the absence of the N-terminal transmembrane-spanning domain. The association of a series of ubiquinone substrates with detergent micelles was studied by isothermal titration calorimetry, and the data reveal that CoQ analogs with long decyl (CoQ(D)) or geranyl (CoQ(2)) tails partition into detergent micelles, whereas that with a short prenyl tail (CoQ(1)) remains in solution. PfDHODH-catalyzed reduction of CoQ(D) and CoQ(2), but not CoQ(1), is stimulated as detergent concentrations (Tween 80 or Triton X-100) are increased up to their critical micelle concentrations, beyond which activity declines. Steady-state kinetic data acquired for the reaction with CoQ(D) and CoQ(2) in substrate-detergent mixed micelles fit well to a surface dilution kinetic model. In contrast, the data for CoQ(1) as a substrate were well described by solution steady-state kinetics. Our results suggest that the partitioning of lipophilic ubiquinone analogues into detergent micelles needs to be an important consideration in the kinetic analysis of enzymes that utilize these substrates.

Subcellular distribution and activation by non-ionic detergents of guanylate cyclase in cerebral cortex of rat.

PubMed

Deguchi, T; Amano, E; Nakane, M

1976-11-01

Non-ionic detergents stimulated particulate guanylate cyclase activity in cerebral cortex of rat 8- to 12-fold while stimulation of soluble enzyme was 1.3- to 2.5-fold. Among various detergents, Lubrol PX was the most effective one. The subcellular distribution of guanylate cyclase activity was examined with or without 0.5% Lubrol PX. Without Lubrol PX two-thirds of the enzyme activity was detected in the soluble fraction. In the presence of Lubrol PX, however, two-thirds of guanylate cyclase activity was recovered in the crude mitochondrial fraction. Further fractionation revealed that most of the particulate guanylate cyclase activity was associated with synaptosomes. The sedimentation characteristic of the particulate guanylate cyclase activity was very close to those of choline acetyltransferase and acetylcholine esterase activities, two synaptosomal enzymes. When the crude mitochondrial fraction was subfractionated after osmotic shock, most of guanylate cyclase activity as assayed in the absence of Lubrol PX was released into the soluble fraction while the rest of the enzyme activity was tightly bound to synaptic membrane fractions. The total guanylate cyclase activity recovered in the synaptosomal soluble fraction was 6 to 7 times higher than that of the starting material. The specific enzyme activity reached more than 1000 pmol per min per mg protein, which was 35-fold higher than that of the starting material. The membrane bound guanylate cyclase activity was markedly stimulated by Lubrol PX. Guanylate cyclase activity in the synaptosomal soluble fraction, in contrast, was suppressed by the addition of Lubrol PX. The observation that most of guanylate cyclase activity was detected in synaptosomes, some of which was tightly bound to the synaptic membrane fraction upon hypoosmotic treatment, is consistent with the concept that cyclic GMP is involved in neural transmission.

Differential solubilization of inner plasma membrane leaflet components by Lubrol WX and Triton X-100.

PubMed

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

2008-01-01

A commonly-used method for analysing raft membrane domains is based on their resistance to extraction by non-ionic detergents at 4 degrees C. However, the selectivity of different detergents in defining raft membrane domains has been questioned. We have compared the lipid composition of detergent-resistant membranes (DRMs) obtained after Triton X-100 or Lubrol WX extraction in MDCK cells in order to understand the differential effect of these detergents on membranes and their selectivity in solubilizing or not proteins. Both Lubrol and Triton DRMs were enriched with cholesterol over the lysate, thus exhibiting characteristics consistent with the properties of membrane rafts. However, the two DRM fractions differed considerably in the ratio between lipids of the inner and outer membrane leaflets. Lubrol DRMs were especially enriched with phosphatidylethanolamine, including polyunsaturated species with long fatty acyl chains. Lubrol and Triton DRMs also differed in the amount of raft transmembrane proteins and raft proteins anchored to the cytoplasmic leaflet. Our results suggest that the inner side of rafts is enriched with phosphatidylethanolamine and cholesterol, and is more solubilized by Triton X-100 than by Lubrol WX.

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.

Effect of surfactants on sorption of atrazine by soil

NASA Astrophysics Data System (ADS)

Abu-Zreig, Majed; Rudra, R. P.; Dickinson, W. T.; Evans, L. J.

1999-03-01

This study investigates the effect of synthetic wastewater containing surfactants on the sorption of atrazine using an equilibrium batch technique. Laboratory experiments were conducted on three soils with two non-ionic (Rexol and Rexonic) surfactants and one anionic (Sulphonic) surfactant, specifically manufactured for the detergent industry. Four sets of experiments were conducted to examine the influence of surfactants on the equilibrium time of atrazine sorption, to explore the effect of surfactant concentration, pH and type of surfactant on the amount of atrazine sorbed and to determine sorption isotherms of atrazine in the presence of surfactants. The results indicate that the application of Sulphonic results in dramatic increase in the adsorption of atrazine on to soils, the increase being directly proportional to the concentration of the surfactant. Application of the Sulphonic surfactants with a concentration of 3000 mg/l can result in a significant increase in Kd values of atrazine for loam and sandy loam soils. On the other hand, the effect of non-ionic surfactants depends on their concentration. Generally, non-ionic surfactants can result in a slight increase in atrazine sorption at high concentration, an exception being Rexol on sandy loam soil. At low concentrations, non-ionic surfactants have shown a tendency to decrease atrazine sorption.

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.

Formulation effects on the mechanical and release properties of metronidazole suppositories.

PubMed

Adegboye, T A; Itiola, O A

2003-09-01

A study of the effects of Tween 20 and Tween 80 non-ionic surfactants, and witepsol H15 and polyethylene glycol (PEG) 2850 bases, on the mechanical and release properties of metronidazole suppositories was made. Mechanical strength was assessed by breaking strength values F. The values of F increased with increase in concentration of surfactant. The values of F for formulations containing Tween 20 were higher than those obtained for formulations containing Tween 80. Witepsol bases gave higher values of F than corresponding PEG bases. Release characteristics were assessed by the time for 80% drug release (t80), values of dissolution rate constants, k1 and k2 and the time of intersection, t1. The values of t80 decreased while those of k1 and k2 increased with increase in surfactant concentration. The values of t80 were lower, while those of k1 and k2 were higher, for formulations containing Tween 20 than for those formulations containing Tween 80. Witepsol bases gave lower t80 values and higher k1 and k2 values than their corresponding PEG bases. The concentration of surfactant, C, had the largest individual effect on the mechanical and release parameters while the nature of surfactant, S, had the lowest. The ranking for the individual effects of the variables on F and k1 was C > N > S, on t80 and k2 was C > N approximately = S, was on t1 was C = N = S. The interactions between S and C were largest for F, t80 and k2, and lowest for k1 and t1. The ranking of the interaction effects of the variables on F and k2 was S-C > N-C > N-S, on t80 was S-C > N-S approximately = N-C, on k1 was N-C > N-S > S-C, and on t1 was N-S = N-C > S-C. The results suggest that the individual and interaction effects of formulation variables would provide useful guides in optimizing metronidazole suppository formulations.

Remediation and desorption kinetics of pyrene from kaolinite co-contaminated with heavy metals at various organic matter contents

NASA Astrophysics Data System (ADS)

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

2017-04-01

Soils co-contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals are challenging for remediation. In the present study desorption of pyrene in kaolinite, co-contaminated by Ni, Pb and Zn, was examined by combinations of surfactants and chelating agents such as Triton X-100, Tween 80, Ethylene diamine tetra acetic acid (EDTA) and citric acid. Results showed that a combination of Triton X-100 (7.5 % w/w) + EDTA (0.01 M) and Tween 80 (7.5 % w/w) + EDTA (0.01 M) were effective in simultaneously desorbing both types of contaminants. Batch desorption tests were conducted using single and combined enhancing agents containing Triton X-100 and Tween 80 as non-ionic surfactants, EDTA as a chelating agent, and citric acid as an organic acid. The solution with the highest removal efficiency was the combined solution containing Triton X-100 (7.5 % w/w) + EDTA (0.01M). Triton X-100 (7.5% w/w) + EDTA (0.01M) led to removal efficiencies of 88% for pyrene in base kaolinite. Batch desorption kinetic experiments were performed using Triton X-100 (7.5% w/w) + EDTA (0.01M). During the first 24 h, desorption was rapid. Organic matter content in the kaolinite led to a reduction in the desorption rate of the contaminants. The desorption kinetic data were well fitted by a pseudo-second-order kinetic model.

Synthesis and functionalization of NaGdF4:Yb,Er@NaGdF4 core-shell nanoparticles for possible application as multimodal contrast agents.

PubMed

Baziulyte-Paulaviciene, Dovile; Karabanovas, Vitalijus; Stasys, Marius; Jarockyte, Greta; Poderys, Vilius; Sakirzanovas, Simas; Rotomskis, Ricardas

2017-01-01

Upconverting nanoparticles (UCNPs) are promising, new imaging probes capable of serving as multimodal contrast agents. In this study, monodisperse and ultrasmall core and core-shell UCNPs were synthesized via a thermal decomposition method. Furthermore, it was shown that the epitaxial growth of a NaGdF 4 optical inert layer covering the NaGdF 4 :Yb,Er core effectively minimizes surface quenching due to the spatial isolation of the core from the surroundings. The mean diameter of the synthesized core and core-shell nanoparticles was ≈8 and ≈16 nm, respectively. Hydrophobic UCNPs were converted into hydrophilic ones using a nonionic surfactant Tween 80. The successful coating of the UCNPs by Tween 80 has been confirmed by Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy (SEM), powder X-ray diffraction (XRD), photoluminescence (PL) spectra and magnetic resonance (MR) T1 relaxation measurements were used to characterize the size, crystal structure, optical and magnetic properties of the core and core-shell nanoparticles. Moreover, Tween 80-coated core-shell nanoparticles presented enhanced optical and MR signal intensity, good colloidal stability, low cytotoxicity and nonspecific internalization into two different breast cancer cell lines, which indicates that these nanoparticles could be applied as an efficient, dual-modal contrast probe for in vivo bioimaging.

The removal of pyroglutamic acid from monoclonal antibodies without denaturation of the protein chains.

PubMed

Werner, William E; Wu, Sylvia; Mulkerrin, Michael

2005-07-01

Typically, the removal of pyroglutamate from the protein chains of immunoglobulins with the enzyme pyroglutamate aminopeptidase requires the use of chaotropic and reducing agents, quite often with limited success. This article describes a series of optimization experiments using elevated temperatures and detergents to denature and stabilize the heavy chains of immunoglobulins such that the pyroglutamate at the amino terminal was accessible to enzymatic removal using the thermostable protease isolated from Pyrococcus furiosus. The detergent polysorbate 20 (Tween 20) was used successfully to facilitate the removal of pyroglutamate residues. A one-step digestion was developed using elevated temperatures and polysorbate 20, rather than chaotropic and reducing agents, with sample cleanup and preparation for Edman sequencing performed using a commercial cartridge containing the PVDF membrane. All of the immunoglobulins digested with this method yielded heavy chain sequence, but the extent of deblocking was immunglobulin dependent (typically>50%).

Dodecyl Maltopyranoside Enabled Purification of Active Human GABA Type A Receptors for Deep and Direct Proteomic Sequencing*

PubMed Central

Zhang, Xi; Miller, Keith W.

2015-01-01

The challenge in high-quality membrane proteomics is all about sample preparation prior to HPLC, and the cell-to-protein step poses a long-standing bottleneck. Traditional protein extraction methods apply ionic or poly-disperse detergents, harsh denaturation, and repeated protein/peptide precipitation/resolubilization afterward, but suffer low yield, low reproducibility, and low sequence coverage. Contrary to attempts to subdue, we resolved this challenge by providing proteins nature-and-activity-promoting conditions throughout preparation. Using 285-kDa hetero-pentameric human GABA type A receptor overexpressed in HEK293 as a model, we describe a n-dodecyl-β-d-maltopyranoside/cholesteryl hemisuccinate (DDM/CHS)-based affinity purification method, that produced active receptors, supported protease activity, and allowed high performance with both in-gel and direct gel-free proteomic analyses—without detergent removal. Unlike conventional belief that detergents must be removed before HPLC MS, the high-purity low-dose nonionic detergent DDM did not interfere with peptides, and obviated removal or desalting. Sonication or dropwise addition of detergent robustly solubilized over 90% of membrane pellets. The purification conditions were comparable to those applied in successful crystallizations of most membrane proteins. These results enabled streamlined proteomics of human synaptic membrane proteins, and more importantly, allowed directly coupling proteomics with crystallography to characterize both static and dynamic structures of membrane proteins in crystallization pipelines. PMID:25473089

A newly high alkaline lipase: an ideal choice for application in detergent formulations

PubMed Central

2011-01-01

Background Bacterial lipases received much attention for their substrate specificity and their ability to function in extreme environments (pH, temperature...). Many staphylococci produced lipases which were released into the culture medium. Reports of thermostable lipases from Staphylococcus sp. and active in alkaline conditions are not previously described. Results A newly soil-isolated Staphylococcus sp. strain ESW secretes an induced lipase in the culture medium. The effects of temperature, pH and various components in a detergent on the activity and stability of Staphylococcus sp. lipase (SL1) were studied in a preliminary evaluation for use in detergent formulation solutions. The enzyme was highly active over a wide range of pH from 9.0 to 13.0, with an optimum at pH 12.0. The relative activity at pH 13.0 was about 60% of that obtained at pH 12.0. It exhibited maximal activity at 60°C. This novel lipase, showed extreme stability towards non-ionic and anionic surfactants after pre-incubation for 1 h at 40°C, and relative stability towards oxidizing agents. Additionally, the crude enzyme showed excellent stability and compatibility with various commercial solid and liquid detergents. Conclusions These properties added to the high activity in high alkaline pH make this novel lipase an ideal choice for application in detergent formulations. PMID:22123072

A new class of sulfoxide surfactants derived from Tris. Synthesis and preliminary assessments of their properties.

PubMed

Barthélémy, P; Maurizis, J C; Lacombe, J M; Pucci, B

1998-06-16

A new class of non-ionic amphiphilic molecules suitable for biological purposes, especially extraction of membrane proteins, is reported. Such surfactants were prepared in two steps: addition of alkyl or fluoroalkyl mercaptan on Tris(hydroxymethyl)acrylamidomethane (THAM) derivatives, followed by the oxydation of sulfide group in sulfoxide moiety in order to provide water solubility to the molecule. The detergent efficiency of these new surfactants were assayed on rat liver cells.

Robustness of solvent/detergent treatment of plasma derivatives: a data collection from Plasma Protein Therapeutics Association member companies.

PubMed

Dichtelmüller, Herbert O; Biesert, Lothar; Fabbrizzi, Fabrizio; Gajardo, Rodrigo; Gröner, Albrecht; von Hoegen, Ilka; Jorquera, Juan I; Kempf, Christoph; Kreil, Thomas R; Pifat, Dominique; Osheroff, Wendy; Poelsler, Gerhard

2009-09-01

Solvent/detergent (S/D) treatment is an established virus inactivation technology that has been applied in the manufacture of medicinal products derived from human plasma for more than 20 years. Data on the inactivation of enveloped viruses by S/D treatment collected from seven Plasma Protein Therapeutics Association member companies demonstrate the robustness, reliability, and efficacy of this virus inactivation method. The results from 308 studies reflecting production conditions as well as technical variables significantly beyond the product release specification were evaluated for virus inactivation, comprising different combinations of solvent and detergent (tri(n-butyl) phosphate [TNBP]/Tween 80, TNBP/Triton X-100, TNBP/Na-cholate) and different products (Factor [F]VIII, F IX, and intravenous and intramuscular immunoglobulins). Neither product class, process temperature, protein concentration, nor pH value has a significant impact on virus inactivation. A variable that did appear to be critical was the concentration of solvent and detergent. The data presented here demonstrate the robustness of virus inactivation by S/D treatment for a broad spectrum of enveloped test viruses and process variables. Our data substantiate the fact that no transmission of viruses such as human immunodeficiency virus, hepatitis B virus, hepatitis C virus, or of other enveloped viruses was reported for licensed plasma derivatives since the introduction of S/D treatment.

Characterization of detergent-solubilized sarcoplasmic reticulum Ca2+-ATPase by high-performance liquid chromatography.

PubMed

Andersen, J P; Vilsen, B; Nielsen, H; Møller, J V

1986-10-21

Sarcoplasmic reticulum Ca2+-ATPase solubilized by the nonionic detergent octaethylene glycol monododecyl ether was studied by molecular sieve high-performance liquid chromatography (HPLC) and analytical ultracentrifugation. Significant irreversible aggregation of soluble Ca2+-ATPase occurred within a few hours in the presence of less than or equal to 50 microM Ca2+. The aggregates were inactive and were primarily held together by hydrophobic forces. In the absence of reducing agent, secondary formation of disulfide bonds occurred. The stability of the inactive dimer upon dilution permitted unambiguous assignment of its elution position and sedimentation coefficient. At high Ca2+ concentration (500 microM), monomeric Ca2+-ATPase was stable for several hours. Reversible self-association induced by variation in protein, detergent, and lipid concentrations was studied by large-zone HPLC. The association constant for dimerization of active Ca2+-ATPase was found to be 10(5)-10(6) M-1 depending on the detergent concentration. More detergent was bound to monomeric than to dimeric Ca2+-ATPase, even above the critical micellar concentration of the detergent. Binding of Ca2+ and vanadate as well as ATP-dependent phosphorylation was studied in monomeric and in reversibly associated dimeric preparations. In both forms, two high-affinity Ca2+ binding sites per phosphorylation site existed. The delipidated monomer purified by HPLC was able to form ADP-insensitive phosphoenzyme and to bind ATP and vanadate simultaneously. These results suggest that formation of Ca2+-ATPase oligomers in the membrane is governed by nonspecific forces (low affinity) and that each polypeptide chain constitutes a functional unit.

Investigation on stabilization of CO2 foam by ionic and nonionic surfactants in presence of different additives for application in enhanced oil recovery

NASA Astrophysics Data System (ADS)

Kumar, Sunil; Mandal, Ajay

2017-10-01

Application of foam in upstream petroleum industry specifically in enhanced oil recovery (EOR) has gained significant interest in recent years. In view of this, an attempt has been paid to design the suitable foaming agents (foamer) by evaluating the influence of three surfactants, five nanoparticles and several additives. Experimental investigations have been carried out in order to examine the mechanism of foam generation in presence of sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and polysorbate 80 (Tween 80) as anionic, cationic and nonionic surfactants by using the CO2 as gaseous component. It has been found that ionic surfactants show the higher foam life compared to nonionic surfactant. Out of different nano particles used, namely alumina (Al2O3) zirconium oxide (ZrO2), calcium carbonate (CaCO3), boron nitride (BN) and silica (SiO2), boron nitride shows the maximum improvement of foam stability. The foam stability of surfactant-nanoparticles foam is further increased by addition of different additives viz. polymer, alcohol and alkali. The results show that, the designed foaming solution have nearly 2.5 times higher half-decay time (t1/2) compared to the simple surfactant system. Finally, it has been found that gas injection rate plays an important role in obtaining a uniform and stabilized foam.

Fluorinated diglucose detergents for membrane-protein extraction.

PubMed

Boussambe, Gildas Nyame Mendendy; Guillet, Pierre; Mahler, Florian; Marconnet, Anaïs; Vargas, Carolyn; Cornut, Damien; Soulié, Marine; Ebel, Christine; Le Roy, Aline; Jawhari, Anass; Bonneté, Françoise; Keller, Sandro; Durand, Grégory

2018-05-29

Fluorinated surfactants have scarcely been explored for the direct extraction of proteins from membranes because fluorination is believed to abrogate detergency. However, we have recently shown that a commercially available fluorinated surfactant readily solubilizes lipid membranes, thereby suggesting that fluorination per se does not interfere with detergent activity. In this work, we developed new fluorinated surfactants that exhibit detergency in terms of both lipid-vesicle solubilization and membrane-protein extraction. The compounds made and tested contain two glucose moieties as polar headgroup, a hydrogenated thioether linker, and a perfluorinated alkyl tail with either 4, 6, or 8 carbon atoms. The physicochemical properties of the micelles formed by the three fluorinated surfactants were evaluated by NMR spectroscopy, surface tensiometry, isothermal titration calorimetry, dynamic light scattering, small-angle X-ray scattering, and analytical ultracentrifugation. At 25°C, micellization was mainly entropy-driven, and the CMC values were found to decrease with chain length of the fluorinated tail, whereas the aggregation number increased with chain length. Remarkably, all three surfactants were found to solubilize lipid vesicles and extract a broad range of proteins from Escherichiacoli membranes. These findings demonstrate, for the first time, that nonionic fluorinated surfactants could be further exploited for the direct extraction and solubilization of membrane proteins. Copyright © 2018. Published by Elsevier Inc.

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.

An organic solvent-stable lipase from a newly isolated Staphylococcus aureus ALA1 strain with potential for use as an industrial biocatalyst.

PubMed

Ben Bacha, Abir; Moubayed, Nadine Ms; Al-Assaf, Alaa

2016-05-01

In this study, a new strain, ALA1, was identified as Staphylococcus aureus by biochemical tests, and its 16S ribosomal DNA sequence was isolated from dromedary milk. ALA1 lipase production was optimized in shake flask experiments and measured with varying pH (3-11), temperature (20-55 °C) and substrate concentrations. The maximum lipase production was recorded at pH 8 and 30 °C for up to 30 H of culture period for the S. aureus ALA1 strain. Among the substrates tested, selected carbon sources, xylose, nitrogen source, yeast extract, and olive oil (1%) were suitable for maximizing lipase production. The effects of surfactants were investigated and showed that Tween 20, Tween 80, and Triton X-100 prevented lipase production. Interestingly, isolate ALA1 was able to grow in high concentrations of benzene or toluene (up to 50% (v/v)). Moreover, the lipolytic activity of the S. aureus ALA1 lipase was stimulated by diethyl ether, whereas almost 100% of S. aureus ALA1 lipase activity was retained in 25% acetone, acetonitrile, benzene, 2-propanol, ethanol, methanol, or toluene. Because of its stability in organic solvent, the S. aureus ALA1 lipase was used as a biocatalyst to synthesize high levels of added value molecules. S. aureus ALA1 lipase could be considered as an ideal choice for applications in detergent formulations because of its high stability and compatibility with various surfactants, oxidizing agents, and commercial detergents. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

Mechanisms of the inhibition of enzymatic hydrolysis of waste pulp fibers by calcium carbonate and the influence of nonionic surfactant for mitigation.

PubMed

Min, Byeong Cheol; Ramarao, Bandaru V

2017-06-01

Recycled paper mills produce large quantities of fibrous rejects and fines which are usually sent to landfills as solid waste. These cellulosic materials can be enzymatically hydrolyzed into sugars for the production of biofuels and biomaterials. Paper mill wastes also contain large amounts of calcium carbonate which inhibits cellulase activity. The calcium carbonate (30%, w/w) decreased 40-60% of sugar yield of unbleached softwood kraft pulp. The prime mechanisms for this are by pH variation, competitive and non-productive binding, and aggregation effect. Addition of acetic acid (pH adjustment) increased the sugar production from 19 to 22 g/L of paper mill waste fibers. Strong affinity of enzyme-calcium carbonate decreased free enzyme in solution and hindered sugar production. Electrostatic and hydrogen bond interactions are mainly possible mechanism of enzyme-calcium carbonate adsorption. The application of the nonionic surfactant Tween 80 alleviated the non-productive binding of enzyme with the higher affinity on calcium carbonate. Dissociated calcium ion also inhibited the hydrolysis by aggregation of enzyme.

[Poisoning by household products].

PubMed

Lambert, H; Manel, J; Gabrion, I

2000-02-15

Caustic products are responsible for the most serious cases of poisoning, which are always emergency cases. Application of current intervention procedures has decreased both morbidity and mortality. Water-diluted bleach, the ingestion of which remains extremely frequent, is a moderate irritant rather than a caustic product. Emission of gas produced when mixing bleach with other agents can be responsible for choking gas poisoning. Anionic and nonionic detergents are mostly dangerous because of their foam-producing properties. Mercury vapours and methanol are other potentially hazardous products.

Properties of lubrol-extracted uridine diphosphate glucuronyltransferase.

PubMed

Howland, R D; Burkhalter, A; Trevor, A J; Hegeman, S; Shirachi, D Y

1971-12-01

1. A partially purified UDP-glucuronyltransferase was obtained by extracting rat liver microsomal preparations with Lubrol, a non-ionic detergent. 2. The soluble enzyme catalysed conjugation of both o-aminophenol and p-nitrophenol and was extremely stable when compared with untreated microsomal preparations. 3. The characteristics of the conjugation of the two phenols were found to differ with respect to pH optimum, bivalent cation requirement and Michaelis constants, suggesting that more than one enzyme is involved in the conjugation reaction.

Properties of Lubrol-extracted uridine diphosphate glucuronyltransferase

PubMed Central

Howland, R. D.; Burkhalter, A.; Trevor, A. J.; Hegeman, S.; Shirachi, D. Y.

1971-01-01

1. A partially purified UDP-glucuronyltransferase was obtained by extracting rat liver microsomal preparations with Lubrol, a non-ionic detergent. 2. The soluble enzyme catalysed conjugation of both o-aminophenol and p-nitrophenol and was extremely stable when compared with untreated microsomal preparations. 3. The characteristics of the conjugation of the two phenols were found to differ with respect to pH optimum, bivalent cation requirement and Michaelis constants, suggesting that more than one enzyme is involved in the conjugation reaction. PMID:5144269

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.

Nanoemulsions stabilized by non-ionic surfactants: stability and degradation mechanisms.

PubMed

Koroleva, M; Nagovitsina, T; Yurtov, E

2018-04-18

The prevailing opinion in the literature is that the main mechanism of O/W nanoemulsion degradation is Ostwald ripening. Nevertheless, the experimental rates of Ostwald ripening are usually several orders of magnitude higher than the theoretical values. This suggests that other mechanisms, such as coalescence, flocculation and subsequent creaming, significantly influence nanoemulsion breakdown. We investigated O/W nanoemulsions stabilized by Brij 30 or by a mixture of Tween 80 and Span 80 and with liquid paraffin as a dispersed phase. The results indicate that Ostwald ripening is the main process leading to nanoemulsion coarsening only in nanoemulsions with low oil phase fractions of up to 0.05. For quasi-steady state conditions the rates of Ostwald ripening are equal to (1.5 ± 0.3) × 10-29 and (1.1 ± 0.3) × 10-29 m3 s-1 in nanoemulsions with Brij 30 and Tween 80 & Span 80, respectively. In nanoemulsions with oil phase fractions of 0.15-0.45, different mechanisms are identified. Flocculation prevails over other processes during the first days in nanoemulsions stabilized by Brij 30. Coalescence is the main mechanism of nanoemulsion degradation for long times. An increase in droplet size 5-10 days after nanoemulsion preparation due to Ostwald ripening takes place in the case of nanoemulsion stabilization by Tween 80 and Span 80. The stability behavior of these nanoemulsions at later stages is distinctly affected by coalescence and flocculation.

Use of two-surfactants mixtures to attain specific HLB values for assisted TPH-diesel biodegradation.

PubMed

Torres, Luis G; Rojas, Neftalí; Iturbe, Rosario

2004-01-01

In a surfactant assisted biodegradation process, the choice of surfactant(s) is of crucial importance. The question is: does the type of surfactant (i.e. chemical family) affect the biodegradation process at fixed hidrophillic-lypofillic balance (HLB) values? Microcosm assessments were developed using contaminated soil, with around of 5000 mg/kg of hydrocarbons as TPH-diesel. Mixtures of three nonionic surfactants were employed to get a wide range of specific HLB values. Tween20 and Span20 were mixed in the appropriate proportions to get HLB values between 8.6 and 16.7. Tween/Span60 mixtures reached HLB values between 4.7 and 14.9. Finally, Tween/Span80 combinations yielded HLB values between 4.3 and 15. TPH-diesel biodegradation was measured at the beginning, and after 8 weeks, as well as the FCU/gr(soil), as a measure of microorganisms' development during the biodegradation period. A second aim of this work was to assess the use of guar gum as a biodegradation enhancer instead of synthetic products. The conclusions of this work are that surfactant chemical family, and not only the HLB value clearly affects the assisted biodegradation rate. Surfactant's synergism was clearly observed. Regarding the use of guar gum, no biodegradation enhancement was observed for the three assessed concentrations, i.e., 2, 20, and 200 mg/kg, respectively. On the contrary, TPH-diesel removal was lower as the gum concentration increased. It is quite possible that guar gum was used as a microbial substrate.

Detergent Isolation Stabilizes and Activates the Shigella Type III Secretion System Translocator Protein IpaC.

PubMed

Bernard, Abram R; Duarte, Shari M; Kumar, Prashant; Dickenson, Nicholas E

2016-07-01

Shigella rely on a type III secretion system as the primary virulence factor for invasion and colonization of human hosts. Although there are an estimated 90 million Shigella infections, annually responsible for more than 100,000 deaths worldwide, challenges isolating and stabilizing many type III secretion system proteins have prevented a full understanding of the Shigella invasion mechanism and additionally slowed progress toward a much needed Shigella vaccine. Here, we show that the non-denaturing zwitterionic detergent N, N-dimethyldodecylamine N-oxide (LDAO) and non-ionic detergent n-octyl-oligo-oxyethylene efficiently isolated the hydrophobic Shigella translocator protein IpaC from the co-purified IpaC/IpgC chaperone-bound complex. Both detergents resulted in monomeric IpaC that exhibits strong membrane binding and lysis characteristics while the chaperone-bound complex does not, suggesting that the stabilizing detergents provide a means of following IpaC "activation" in vitro. Additionally, biophysical characterization found that LDAO provides significant thermal and temporal stability to IpaC, protecting it for several days at room temperature and brief exposure to temperatures reaching 90°C. In summary, this work identified and characterized conditions that provide stable, membrane active IpaC, providing insight into key interactions with membranes and laying a strong foundation for future vaccine formulation studies taking advantage of the native immunogenicity of IpaC and the stability provided by LDAO. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Characterization of Hydrophobic Peptides in the Presence of Detergent by Photoionization Mass Spectrometry

PubMed Central

Bagag, Aïcha; Jault, Jean-Michel; Sidahmed-Adrar, Nazha; Réfrégiers, Matthieu; Giuliani, Alexandre; Le Naour, François

2013-01-01

The characterization of membrane proteins is still challenging. The major issue is the high hydrophobicity of membrane proteins that necessitates the use of detergents for their extraction and solubilization. The very poor compatibility of mass spectrometry with detergents remains a tremendous obstacle in studies of membrane proteins. Here, we investigated the potential of atmospheric pressure photoionization (APPI) for mass spectrometry study of membrane proteins. This work was focused on the tetraspanin CD9 and the multidrug transporter BmrA. A set of peptides from CD9, exhibiting a broad range of hydropathicity, was investigated using APPI as compared to electrospray ionization (ESI). Mass spectrometry experiments revealed that the most hydrophobic peptides were hardly ionized by ESI whereas all peptides, including the highly hydrophobic one that corresponds to the full sequence of the first transmembrane domain of CD9, were easily ionized by APPI. The native protein BmrA purified in the presence of the non-ionic detergent beta-D-dodecyl maltoside (DDM) was digested in-solution using trypsin. The resulting peptides were investigated by flow injection analysis of the mixture followed by mass spectrometry. Upon ESI, only detergent ions were detected and the ionic signals from the peptides were totally suppressed. In contrast, APPI allowed many peptides distributed along the sequence of the protein to be detected. Furthermore, the parent ion corresponding to the first transmembrane domain of the protein BmrA was detected under APPI conditions. Careful examination of the APPI mass spectrum revealed a-, b-, c- and y- fragment ions generated by in-source fragmentation. Those fragment ions allowed unambiguous structural characterization of the transmembrane domain. In conclusion, APPI–MS appears as a versatile method allowing the ionization and fragmentation of hydrophobic peptides in the presence of detergent. PMID:24236085

n-Dodecyl β-D-maltoside specifically competes with general anesthetics for anesthetic binding sites.

PubMed

Xu, Longhe; Matsunaga, Felipe; Xi, Jin; Li, Min; Ma, Jingyuan; Liu, Renyu

2014-01-01

We recently demonstrated that the anionic detergent sodium dodecyl sulfate (SDS) specifically interacts with the anesthetic binding site in horse spleen apoferritin, a soluble protein which models anesthetic binding sites in receptors. This raises the possibility of other detergents similarly interacting with and occluding such sites from anesthetics, thereby preventing the proper identification of novel anesthetic binding sites. n-Dodecyl β-D-maltoside (DDM) is a non-ionic detergent commonly used during protein-anesthetic studies because of its mild and non-denaturing properties. In this study, we demonstrate that SDS and DDM occupy anesthetic binding sites in the model proteins human serum albumin (HSA) and horse spleen apoferritin and thereby inhibit the binding of the general anesthetics propofol and isoflurane. DDM specifically interacts with HSA (Kd = 40 μM) with a lower affinity than SDS (Kd = 2 μM). DDM exerts all these effects while not perturbing the native structures of either model protein. Computational calculations corroborated the experimental results by demonstrating that the binding sites for DDM and both anesthetics on the model proteins overlapped. Collectively, our results indicate that DDM and SDS specifically interact with anesthetic binding sites and may thus prevent the identification of novel anesthetic sites. Special precaution should be taken when undertaking and interpreting results from protein-anesthetic investigations utilizing detergents like SDS and DDM.

Manipulating interactions between functional colloidal particles and polyethylene surfaces using interfacial engineering.

PubMed

Ziani, Khalid; Barish, Jeffrey A; McClements, David Julian; Goddard, Julie M

2011-08-01

The purpose of this study was to examine the interaction between lipid droplets and polyethylene surfaces, representative of those commonly used in food packaging. Lipid droplets with various surface charges were prepared by homogenizing corn oil and water in the presence of surfactants with different electrical characteristics: non-ionic (Tween 80, T80), cationic (lauric arginate, LAE), and/or anionic (sodium dodecyl sulfate, SDS). The ionic properties of polyethylene surfaces were modified by UV-treatment. Stable emulsions containing small droplets (d<200 nm) with nearly neutral (T80), cationic (T80: LAE), and anionic (T80: SDS) charges were prepared by adding different levels of the ionic surfactants to Tween 80 stabilized emulsions. Scanning electronic microscopy (SEM), confocal fluorescence microscopy, and ATR-FTIR showed that the number of droplets attached to the polyethylene surfaces depended on the droplet charge and the polyethylene surface characteristics. The greatest degree of droplet adsorption was observed for the cationic droplets to the UV-ozone treated polyethylene surfaces, which was attributed to electrostatic attraction. These results are important for understanding the behavior of encapsulated lipophilic components in food containers. Copyright © 2011 Elsevier Inc. All rights reserved.

Phase behavior, microstructural transition, antimicrobial and antioxidant activities of a water-dilutable thymol microemulsion.

PubMed

Deng, Lingli; Taxipalati, Maierhaba; Sun, Ping; Que, Fei; Zhang, Hui

2015-12-01

Pseudo ternary phase diagrams were constructed to assess the dilutability of thymol microemulsions using non-ionic (Tween 80), cationic (CTAB), and anionic (SDS) surfactants. We successfully constructed a thymol U-type microemulsion system using Tween 80 as surfactant and studied the microstructural transition along the dilution line at a 90/10 surfactant/oil mass ratio, with thymol and ethanol (3:1, w/w) as the oil phase. Differential scanning calorimetry analysis suggested that the microemulsions gradually inverted from the water-in-oil (W/O) (0-20% water) to the bicontinuous (25-35% water), and finally to the oil-in-water (O/W) (40-90% water) microstructures upon dilution, in good agreement with the conductivity measurements, while the rheological results indicated the collapse of rod-like micelles followed by formation of spherical micelles in the O/W region. The activities of the U-type thymol microemulsions are structural dependent. The antimicrobial activity against Escherichia coli and Staphylococcus aureus decreased when the microemulsions transformed from W/O to bicontinuous and O/W structures, while the DPPH scavenging activity increased. Copyright © 2015 Elsevier B.V. All rights reserved.

Polysorbates 20 and 80 used in the formulation of protein biotherapeutics: structure and degradation pathways.

PubMed

Kerwin, Bruce A

2008-08-01

Polysorbates 20 and 80 (Tween 20 and Tween 80) are used in the formulation of biotherapeutic products for both preventing surface adsorption and as stabilizers against protein aggregation. The polysorbates are amphipathic, nonionic surfactants composed of fatty acid esters of polyoxyethylene sorbitan being polyoxyethylene sorbitan monolaurate for polysorbate 20 and polyoxyethylene sorbitan monooleate for polysorbate 80. The polysorbates used in the formulation of biopharmaceuticals are mixtures of different fatty acid esters with the monolaurate fraction of polysorbate 20 making up only 40-60% of the mixture and the monooleate fraction of polysorbate 80 making up >58% of the mixture. The polysorbates undergo autooxidation, cleavage at the ethylene oxide subunits and hydrolysis of the fatty acid ester bond. Autooxidation results in hydroperoxide formation, side-chain cleavage and eventually formation of short chain acids such as formic acid all of which could influence the stability of a biopharmaceutical product. Oxidation of the fatty acid moiety while well described in the literature has not been specifically investigated for polysorbate. This review focuses on the chemical structure of the polysorbates, factors influencing micelle formation and factors and excipients influencing stability and degradation of the polyoxyethylene and fatty acid ester linkages.

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.

Preparation of factor VII concentrate using CNBr-activated Sepharose 4B immunoaffinity chromatography

PubMed Central

Mousavi Hosseini, Kamran; Nasiri, Saleh

2015-01-01

Background: Factor VII concentrates are used in patients with congenital or acquired factor VII deficiency or treatment of hemophilia patients with inhibitors. In this research, immunoaffinity chromatography was used to purify factor VII from prothrombin complex (Prothrombin- Proconvertin-Stuart Factor-Antihemophilic Factor B or PPSB) which contains coagulation factors II, VII, IX and X. The aim of this study was to improve purity, safety and tolerability as a highly purified factor VII concentrate. Methods: PPSB was prepared using DEAE-Sephadex and was used as the starting material for purification of coagulation factor VII. Prothrombin complex was treated by solvent/detergent at 24°C for 6 h with constant stirring. The mixture of PPSB in the PBS buffer was filtered and then chromatographed using CNBr-activated Sepharose 4B coupled with specific antibody. Factors II, IX, VII, X and VIIa were assayed on the fractions. Fractions of 48-50 were pooled and lyophilized as a factor VII concentrate. Agarose gel electrophoresis was performed and Tween 80 was measured in the factor VII concentrate. Results: Specific activity of factor VII concentrate increased from 0.16 to 55.6 with a purificationfold of 347.5 and the amount of activated factor VII (FVIIa) was found higher than PPSB (4.4-fold). Results of electrophoresis on agarose gel indicated higher purity of Factor VII compared to PPSB; these finding revealed that factor VII migrated as alpha-2 proteins. In order to improve viral safety, solvent-detergent treatment was applied prior to further purification and nearly complete elimination of tween 80 (2 μg/ml). Conclusion: It was concluded that immuonoaffinity chromatography using CNBr-activated Sepharose 4B can be a suitable choice for large-scale production of factor VII concentrate with higher purity, safety and activated factor VII. PMID:26034723

Preparation of factor VII concentrate using CNBr-activated Sepharose 4B immunoaffinity chromatography.

PubMed

Mousavi Hosseini, Kamran; Nasiri, Saleh

2015-01-01

Factor VII concentrates are used in patients with congenital or acquired factor VII deficiency or treatment of hemophilia patients with inhibitors. In this research, immunoaffinity chromatography was used to purify factor VII from prothrombin complex (Prothrombin- Proconvertin-Stuart Factor-Antihemophilic Factor B or PPSB) which contains coagulation factors II, VII, IX and X. The aim of this study was to improve purity, safety and tolerability as a highly purified factor VII concentrate. PPSB was prepared using DEAE-Sephadex and was used as the starting material for purification of coagulation factor VII. Prothrombin complex was treated by solvent/detergent at 24°C for 6 h with constant stirring. The mixture of PPSB in the PBS buffer was filtered and then chromatographed using CNBr-activated Sepharose 4B coupled with specific antibody. Factors II, IX, VII, X and VIIa were assayed on the fractions. Fractions of 48-50 were pooled and lyophilized as a factor VII concentrate. Agarose gel electrophoresis was performed and Tween 80 was measured in the factor VII concentrate. Specific activity of factor VII concentrate increased from 0.16 to 55.6 with a purificationfold of 347.5 and the amount of activated factor VII (FVIIa) was found higher than PPSB (4.4-fold). RESULTS of electrophoresis on agarose gel indicated higher purity of Factor VII compared to PPSB; these finding revealed that factor VII migrated as alpha-2 proteins. In order to improve viral safety, solvent-detergent treatment was applied prior to further purification and nearly complete elimination of tween 80 (2 μg/ml). It was concluded that immuonoaffinity chromatography using CNBr-activated Sepharose 4B can be a suitable choice for large-scale production of factor VII concentrate with higher purity, safety and activated factor VII.

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.

Multimeric species in equilibrium in detergent-solubilized Na,K-ATPase.

PubMed

Yoneda, Juliana Sakamoto; Scanavachi, Gustavo; Sebinelli, Heitor Gobbi; Borges, Júlio Cesar; Barbosa, Leandro R S; Ciancaglini, Pietro; Itri, Rosangela

2016-08-01

In this work, we find an equilibrium between different Na,K-ATPase (NKA) oligomeric species solubilized in a non-ionic detergent C12E8 by means of Dynamic Light Scattering (DLS), Analytical Ultracentrifugation (AUC), Small Angle X-ray Scattering (SAXS), Spectrophotometry (absorption at 280/350nm) and enzymatic activity assay. The NKA sample after chromatography purification presented seven different populations as identified by AUC, with monomers and tetramers amounting to ∼55% of the total protein mass in solution. These two species constituted less than 40% of the total protein mass after increasing the NKA concentration. Removal of higher-order oligomer/aggregate species from the NKA solution using 220nm-pore filter resulted in an increase of the specific enzymatic activity. Nevertheless, the enzyme forms new large aggregates over an elapsed time of 20h. The results thus point out that C12E8-solubilized NKA is in a dynamic equilibrium of monomers, tetramers and high-order oligomers/subunit aggregates. These latter have low or null activity. High amount of detergent leads to the dissociation of NKA into smaller aggregates with no enzymatic activity. Copyright © 2016. Published by Elsevier B.V.

Purification and Characterization of a Cold-Adapted Lipase from Oceanobacillus Strain PT-11

PubMed Central

Jiewei, Tian; Zuchao, Lei; Peng, Qiu; Lei, Wang; Yongqiang, Tian

2014-01-01

We isolated a moderately halophilic lipase-producing bacterium from the saline soil. Based on the morphological, physiological, chemotaxonomic and phylogenetic analysis, the isolate PT-11 was postulated to be a novel species identified as Oceanobacillus rekensis PT-11. The lipase was purified 2.50-fold by Q-Sepharose FF and SP-Sepharose FF chromatography and its molecular mass was estimated to be 23.5 kDa by SDS-PAGE. It was highly active over the broad temperature ranging from 10 to 35°C and showed up to 80% of the maximum activity at 10°C indicating the lipase to be a typical cold-adapted enzyme. The enzyme activity was slightly enhanced by Na+, Li+ and K+. Incubation with detergents, such as Tween-20 and Tween-80, slightly inhibited the enzyme activity; while Triton X-100decreased the enzyme activity. The enzyme was fairly stable in the presence of long-chain alcohols but was highly denatured in hydrophilic solvents such as acetone or short-chain alcohols (C1–C3). PMID:24984141

Stability and detergent compatibility of a predominantly β-sheet serine protease from halotolerant B. aquimaris VITP4 strain.

PubMed

Thaz, Chittoor Jabeena; Jayaraman, Gurunathan

2014-01-01

The present study deals with the characterization of halotolerant protease produced by Bacillus aquimaris VITP4 strain isolated from Kumta coast, Karnataka, India. The studies were performed at 40 °C and pH 8 in Tris buffer. Metal ions such as Mn(2+) and Ca(2+) increased the proteolytic activity of the enzyme by 34 and 30 %, respectively, at 10 mM concentration. Cu(2+) at 1 mM concentration was found to enhance the enzyme activity by 16 %, whereas inhibition was observed at higher concentration (>5 mM). Slight inhibition was observed even with lower (>1 mM) concentrations of Zn(2+), Hg(2+), Fe(3+), Ni(2+), and Co(2+).The activity of protease was completely inhibited by phenylmethylsulfonyl fluoride, indicating that the VITP4 protease is a serine protease. The presence of ethylenediaminetetraacetic acid and 1,10-phenanthroline (>5 mM) moderately inhibited the activity, suggesting that the enzyme is activated by metal ions. The protease was purified to homogeneity with a purification fold of 15.7 with ammonium sulfate precipitation and 46.65 with gel filtration chromatography using Sephadex G-100, resulting in a specific activity of 424 ± 2.6 U mg(-1). The VITP4 protease consists of a single polypeptide chain with a molecular mass of 34.7 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight. Among the different substrates used (casein, egg albumin, gelatin, and bovine serum albumin), the activity was higher with casein with V max, K m, and k cat values of 0.817 mg ml min(-1), 0.472 mg ml(-1), and 2.31 s(-1), respectively. Circular dichroism studies revealed that the VITP4 protease has a predominantly β-sheet structure (51.6 %) with a temperature for half denaturation of 85.8 °C in the presence of 1 mM CaCl2. Additionally, the VITP4 protease was found to retain more than 70 % activity in the presence of 10 mM concentration of different detergents (CTAB, urea, and sodium dodecyl sulfate) and surfactants (Triton X-100, Tween-20, and Tween-80), and the results of wash performance test with various commercial detergents confirmed that it can be used in detergent formulations.

Influence of aqueous media properties on aggregation and solubility of four structurally related meso-porphyrin photosensitizers evaluated by spectrophotometric measurements.

PubMed

Sobczyński, J; Tønnesen, H H; Kristensen, S

2013-02-01

Porphyrin photosensitizers tend to aggregate in aqueous solutions even in the micromolar concentration range. This is a challenge during formulation of e.g., parenteral preparations for photodynamic cancer therapy, or preparations for local or topical administration in antimicrobial photodynamic therapy. Monomerization is essential to achieve biocompatible drug formulations of high bioavailability and physiological response (i.e., photoreactivity) and low toxicity. The aggregation and solubilization of four structurally related meso-tetraphenyl porphyrin photosensitizers with nonionic (4-hydroxy), anionic (4-sulphonate; 4-carboxy) and cationic (4-trimethylanilinium) substituents were evaluated in various vehicles by use of UV-Vis spectroscopy. Substituents, overall charge and charge distribution influenced the pKa-values and interaction of the porphyrins with different solvents, excipients and impurities. Modification of medium polarity and solubilization by the nonionic surfactant Tween 80 adjusted the acid-base equilibria and increased the solubility by reduction of porphyrin aggregation. The selected porphyrins were sensitive towards ionic strength, temperature and inorganic impurities to various extents. The results will be further used during development of parenteral and topical formulations of porphyrin photosensitizers for use in photodynamic therapy of cancer and bacterial infections.

Synthesis, Surface Parameters, and Biodegradability of Water-soluble Surfactants for Various Applications.

PubMed

El-Sayed, Refat; Alotaibi, Hawazin H; Elhady, Heba A

2018-01-01

The synthesis of water-soluble heterocyclic compounds was verified on the basis of nonionic surfactants for use as surface-active agents. Surface characteristics such as surface and interfacial tensions, cloud point, wetting time, emulsion stability, foaming height and foaming stability were measured for these surface factors in aqueous solutions. In addition, the critical micelle concentration (CMC), the surface pressure at CMC (π cmc ), the effectiveness of surface tension reduction (pC 20 ), the maximum surface concentration (Γ ma. ) and the minimum area/molecule at the aqueous solution/air interface (A min ) were calculated. Moreover, the biodegradability for these nonionic surfactants has been investigated. Furthermore, the antimicrobial evaluation has been evaluated with some surfactants that have demonstrated a potent cytotoxicity as antibacterial, antifungal and anticancer. These surfactants have a good water solubility, low toxicity, environmentally friendly environment, high foam, good emulsifier and easy production that will be used them in various fields such as medical drugs, insecticides, detergents, emulsifiers, cosmetics, inks clothing, leather industry and oil recovery.

Rationalizing lipid nanoemulsion formation for utilization in the food and beverage industry

NASA Astrophysics Data System (ADS)

Rao, Jiajia

There is growing interest in the use of nanoemulsions as delivery systems for lipophilic functional agents in food and beverage products due to their high optical clarity, physical stability and bioavailability. The goal of this research is to establish quantitative structure-function relationships to allow rational formulation of food-grade nanoemulsions for food and beverage applications. Initially, formation of oil-in-water nanoemulsions using a low energy method was examined. Nanoemulsions were formed using the phase inversion temperature (PIT) method, which involves heating a surfactant, oil, water (SOW) systems near the PIT, and then cooling rapidly with stirring. Preliminary experiments were carried out using a model system consisting of a non-ionic surfactant (C12E4), hydrocarbon oil (tetradecane), and water. Nanoemulsions were formed by holding SOW mixtures near their PIT (38.5 °C) and then cooling them rapidly to 10 °C. The PIT was measured using electrical, conductivity and turbidity methods. The optimum storage temperature for PIT-nanoemulsions was about 27 °C lower than the PIT. The stability of PIT-nanoemulsions at ambient temperatures can be improved by adding either Tween 80 (0.2 wt%) or SDS (0.1 wt%) to displace the C12E4 (Brij 30) from the nano-droplet surfaces. Experiments were then carried out to establish if stable nanoemulsions could be formed using the PIT method from food-grade ingredients. Nanoemulsions were fabricated from a non-ionic surfactant (Tween 80) and flavor oil (lemon oil) by heat treatment. Different types of colloidal dispersion could be formed by simple heat treatment (90 °C, 30 minutes) depending on the surfactant-to-oil ratio (SOR): emulsions at SOR < 1; nanoemulsions at 1 < SOR < 2; microemulsions at SOR > 2. The results suggested that there was a kinetic energy barrier in the SOW system at ambient temperature that prevented it from moving from a highly unstable system into a nanoemulsion system. The conditions where stable nanoemulsions could be fabricated were also established when sucrose monopalmitate (SMP) and lemon oil were used as the surfactant and oil phase. Nanoemulsions (r < 100 nm) were formed at low surfactant-to-oil ratios (SOR < 1) depending on homogenization conditions, whereas microemulsions (r < 10 nm) were formed at higher ratios (SOR > 1). Relatively stable nanoemulsions could be formed at pH 6 and 7, but extensive particle growth/aggregation occurred at lower and higher pH values. Flavor oil nanoemulsions were also formed using an emulsion titration method that involves titration of emulsion droplets into surfactant micelle solutions. In this study, the effectiveness of nanoemulsion formation using nonionic surfactants (sucrose monopalmitate (SMP) and/or Tween 80 (T80) was investigated. Lemon oil was transferred from emulsion droplets into the micelle phase until a critical lemon oil concentration (Csat ) was reached. The solubilization process was rapid (< few minutes), with the rate increasing with increasing surfactant concentration. The value of Csat increased with increasing surfactant concentration and was higher for SMP than Tween 80. The influence of lemon oil composition (1x, 3x, 5x, and 10x) on the formation and properties of oil-in-water nanoemulsions was also studied. Initially, the composition, molecular characteristics, and physicochemical properties of four lemon oils were established. The main constituents in 1-fold lemon oil were monoterpenes (> 90 %), whereas the major constituents in 10-fold lemon oil were monoterpenes (≈ 35%), sesquiterpenes (≈ 14%) and oxygenates (≈ 33%). The density, interfacial tension, viscosity, and refractive index of the lemon oils increased as the oil fold increased ( i.e., 1x < 3x < 5x < 10x). The stability of oil-in-water nanoemulsions produced by high pressure homogenization was strongly influenced by lemon oil composition. The lower fold oils were highly unstable to droplet growth during storage (1x, 3x, 5x) with the growth rate increasing with increasing storage temperature and decreasing oil fold. Oil fold also affected the solubilization and stability of lemon oil nanoemulsions titrated into a non-ionic surfactant (Tween 80) solution. The movement of oil molecules from nanoemulsion droplets to surfactant micelles increased with increasing lemon oil fold. Finally, nanoemulsions were used as delivery systems for beta-carotene, a bioactive lipophilic component. The influence of carrier oil composition (ratio of digestible to indigestible oil) on the physical stability, microstructure, and bioaccessibility of beta-carotene nanoemulsions was investigated using a simulated gastrointestinal tract model. The extent of free fatty acid production in the small intestine increased as the amount of digestible oil in the droplets increased. The bioaccessibility of beta-carotene also increased with increasing digestible oil content, ranging from ≈ 5% for the pure lemon oil system to ≈ 76% for the pure corn oil system.

pKa values of hyodeoxycholic and cholic acids in the binary mixed micelles sodium-hyodeoxycholate-Tween 40 and sodium-cholate-Tween 40: Thermodynamic stability of the micelle and the cooperative hydrogen bond formation with the steroid skeleton.

PubMed

Poša, Mihalj; Pilipović, Ana; Bećarević, Mirjana; Farkaš, Zita

2017-01-01

Due to a relatively small size of bile acid salts, their mixed micelles with nonionic surfactants are analysed. Of the special interests are real binary mixed micelles that are thermodynamically more stable than ideal mixed micelles. Thermodynamic stability is expressed with an excess Gibbs energy (G E ) or over an interaction parameter (β ij ). In this paper sodium salts of cholic (C) and hyodeoxycholic acid (HD) in their mixed micelles with Tween 40 (T40) are analysed by potentiometric titration and their pKa values are determined. Examined bile acids in mixed micelles with T40 have higher pKa values than free bile acids. The increase of ΔpKa acid constant of micellary bound C and HD is in a correlation with absolute values of an interaction parameter. According to an interaction parameter and an excess Gibbs energy, mixed micelle HD-T40 are thermodynamically more stable than mixed micelles C-T40. ΔpKa values are higher for mixed micelles with Tween 40 whose second building unit is HD, related to the building unit C. In both micellar systems, ΔpKa increases with the rise of a molar fraction of Tween 40 in binary mixtures of surfactants with sodium salts of bile acids. This suggests that, ΔpKa can be a measure of a thermodynamic stabilization of analysed binary mixed micelles as well as an interaction parameter. ΔpKa values are confirmed by determination of a distribution coefficient of HD and C in systems: water phase with Tween 40 in a micellar concentration and 1-octanol, with a change of a pH value of a water phase. Conformational analyses suggests that synergistic interactions between building units of analysed binary micelles originates from formation of hydrogen bonds between steroid OH groups and polyoxyethylene groups of the T40. Relative similarity and spatial orientation of C 3 and C 6 OH group allows cooperative formation of hydrogen bonds between T40 and HD - excess entropy in formation of mixed micelle. If a water solution of analysed binary mixtures of surfactants contains urea in concentration of 4M significant decreases of an interaction parameter value happens which confirms the importance of hydrogen bonds in synergistic interactions (urea compete in hydrogen bonds). Copyright © 2016 Elsevier Inc. All rights reserved.

Adsorption of anionic and nonionic surfactant mixtures from synthetic detergents on soils.

PubMed

Rao, Pinhua; He, Ming

2006-05-01

Adsorption of anionic surfactant (sodium dodecylbenzenesulfonate, SDBS) and nonionic surfactant (an alcohol ethoxylates with 12 carbons and 9 oxyethyl groups, A12E9) mixtures, widely used as the major constituents of synthetic detergents in China and become the most common pollutants in the environment, on soils was conducted to investigate the behavior of mixed surfactants in soils. The effects of addition order and mixing ratios of two surfactants, associated with pH and ion strength in solutions, on adsorptions were considered. The results show that saturated adsorption amount of SDBS and A12E9 on soils decreased respectively when A12E9 was added into soils firstly compared with that secondly, possibly resulting from the screening of A12E9 to part adsorption sites on soils and the hydrocarbon chain-chain interactions between SDBS and A12E9. The adsorption of SDBS and A12E9 on soils was enhanced each other at pre-plateau region of isotherms. At plateau region of isotherms, the adsorption of SDBS on soils decreased with the increase of molar fraction of A12E9 in mixed surfactant solutions, while that of A12E9 increased except the molar ratio of SDBS to A12E9 0.0:1.0. With the increase of pH in mixed surfactant solutions, adsorption amount of SDBS and A12E9 on soils decreased, respectively. The reduction of ion strength in soils resulted in the decrease of adsorption amount of SDBS and A12E9 on soils, respectively.

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.

A dynamic distention protocol for whole-organ bladder decellularization: histological and biomechanical characterization of the acellular matrix.

PubMed

Consolo, F; Brizzola, S; Tremolada, G; Grieco, V; Riva, F; Acocella, F; Fiore, G B; Soncini, M

2016-02-01

A combined physical-chemical protocol for whole full-thickness bladder decellularization is proposed, based on organ cyclic distention through repeated infusion/withdrawal of the decellularization agents through the urethra. The dynamic decellularization was intended to enhance cell removal efficiency, facilitating the delivery of detergents within the inner layers of the tissue and the removal of cell debris. The use of mild chemical detergents (hypotonic solution and non-ionic detergent) was employed to limit adverse effects upon matrix 3D ultrastructure. Inspection of the presence of residual DNA and RNA was carried out on decellularized matrices to verify effective cell removal. Histological investigation was focused on assessing the retention of adequate structural and functional components that regulate the biomechanical behaviour of the acellular tissue. Biomechanical properties were evaluated through uniaxial tensile loading tests of tissue strips and through ex vivo filling cystometry to evaluate the whole-organ mechanical response to a physiological-like loading state. According to our results, a dynamic decellularization protocol of 17 h duration with a 5 ml/min detergent infusion flow rate revealed higher DNA removal efficiency than standard static decellularization, resulting in residual DNA content < 50 ng/mg dry tissue weight. Furthermore, the collagen network and elastic fibres distribution were preserved in the acellular ECM, which exhibited suitable biomechanical properties in the perspective of its future use as an implant for bladder augmentation. Copyright © 2013 John Wiley & Sons, Ltd.

FOLDING OF DIPHTHERIA TOXIN T-DOMAIN IN THE PRESENCE OF AMPHIPOLS AND FLUORINATED SURFACTANTS: TOWARD THERMODYNAMIC MEASUREMENTS OF MEMBRANE PROTEIN FOLDING

PubMed Central

Kyrychenko, Alexander; Rodnin, Mykola V.; Vargas-Uribe, Mauricio; Sharma, Shivaji K.; Durand, Grégory; Pucci, Bernard; Popot, Jean-Luc; Ladokhin, Alexey S.

2011-01-01

Solubilizing membrane proteins for functional, structural and thermodynamic studies is usually achieved with the help of detergents, which tend to destabilize them, however. Several classes of non-detergent surfactants have been designed as milder substitutes for detergents, most prominently amphipathic polymers called 'amphipols' and fluorinated surfactants. Here we test the potential usefulness of these compounds for thermodynamic studies by examining their effect on conformational transitions of the diphtheria toxin T-domain. The advantage of the T-domain as a model system is that it exists as a soluble globular protein at neutral pH yet is converted into a membrane-competent form by acidification and inserts into the lipid bilayer as part of its physiological action. We have examined the effects of various surfactants on two conformational transitions of the T-domain, thermal unfolding and pH-induced transition to a membrane-competent form. All tested detergent and non-detergent surfactants lowered the cooperativity of the thermal unfolding of the T-domain. The dependence of enthalpy of unfolding on surfactant concentration was found to be least for fluorinated surfactants, thus making them useful candidates for thermodynamic studies. Circular dichroism measurements demonstrate that non-ionic homo-polymeric amphipols (NAhPols), unlike any other surfactants, can actively cause a conformational change of the T-domain. NAhPol-induced structural rearrangements are different from those observed during thermal denaturation and are suggested to be related to the formation of the membrane-competent form of the T-domain. Measurements of vesicle content leakage indicate that interaction with NAhPols not only does not prevent the T-domain from inserting into the bilayer, but it can make bilayer permeabilization even more efficient, whereas the pH-dependence of membrane permeabilization becomes more cooperative. PMID:21945883

Immobilization of enzymes using non-ionic colloidal liquid aphrons (CLAs): Surface and enzyme effects.

PubMed

Ward, Keeran; Xi, Jingshu; Stuckey, David C

2015-12-01

The use of non-ionic colloidal liquid aphrons (CLAs) as a support for enzyme immobilisation was investigated. Formulation required the mixing of an aqueous-surfactant solution with a relatively non-polar solvent-surfactant solution, forming a solvent droplet surrounded by a thin stabilised aqueous film (soapy shell). Studies utilising anionic surfactants have showed increased retention, however, very little have been understood about the forces governing immobilisation. This study seeks to determine the effects of enzyme properties on CLA immobilisation by examining a non-ionic/non-polar solvent system comprised of two non-ionic surfactants, Tween 20 and 80, mineral oil and the enzymes lipase, aprotinin and α-chymotrypsin. From these results it was deduced that hydrophobic interactions strongly governed immobilisation. Confocal Scanning Laser Microscopy (CSLM) revealed that immobilisation was predominantly achieved by surface adsorption attributed to hydrophobic interactions between the enzyme and the CLA surface. Enzyme surface affinity was found to increase when added directly to the formulation (pre-manufacture addition), as opposed to the bulk continuous phase (post-manufacture addition), with α-chymotrypsin and aprotinin being the most perturbed, while lipase was relatively unaffected. The effect of zeta potential on immobilisation showed that enzymes adsorbed better closer to their pI, indicating that charge minimisation was necessary for immobilisation. Finally, the effect of increasing enzyme concentration in the aqueous phase resulted in an increase in adsorption for all enzymes due to cooperativity between protein molecules, with saturation occurring faster at higher adsorption rates. Copyright © 2015 Elsevier B.V. All rights reserved.

Production and characterization of thermostable alkaline protease of Bacillus subtilis (ATCC 6633) from optimized solid-state fermentation.

PubMed

Chatterjee, Joyee; Giri, Sudipta; Maity, Sujan; Sinha, Ankan; Ranjan, Ashish; Rajshekhar; Gupta, Suvroma

2015-01-01

Proteases are the most important group of enzymes utilized commercially in various arenas of industries, such as food, detergent, leather, dairy, pharmaceutical, diagnostics, and waste management, accounting for nearly 20% of the world enzyme market. Microorganisms of specially Bacillus genera serve as a vast repository of diverse set of industrially important enzymes and utilized for the large-scale enzyme production using a fermentation technology. Approximately 30%-40% of the cost of industrial enzymes originates from the cost of the growth medium. This study is attempted to produce protease from Bacillus subtilis (ATCC 6633) after optimization of various process parameters with the aid of solid-state fermentation using a cheap nutrient source such as wheat bran. B. subtilis (ATCC 6633) produces proteases of molecular weight 36 and 20 kDa, respectively, in the fermented medium as evident from SDS zymogram. Alkaline protease activity has been detected with optimum temperature at 50 °C and is insensitive to ethylenediaminetetraacetic acid. This thermostable alkaline protease exhibits dual pH optimum at 7 and 10 with moderate pH stability at alkaline pH range. It preserves its activity in the presence of detergent such as SDS, Tween 20, and Triton X-100 and may be considered as an effective additive to detergent formulation with some industrial importance. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Lactoperoxidase catalyzed radioiodination of cell surface immunoglobulin: incorporated radioactivity may not reflect relative cell surface Ig density. [/sup 125/I

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

Wilder, R.L.; Yuen, C.C.; Mage, R.G.

1979-02-01

Rabbit and mouse splenic lymphocytes were radioiodinated by the lactoperoxidase technique, extracted with non-ionic detergent, immunoprecipitated with high titered rabbit anti-kappa antisera, and compared by SDS-PAGE. Mouse sIg peaks were reproducibly larger in size than rabbit sIg peaks (often greater than 10 times). Neither differences in incorporation of label into the rabbit cell surface, nor differences in average sIg density explain this result. Total TCA-precipitable radioactivity was similar in each species. Estimation of the relative amounts of sIg in the mouse and rabbit showed similar average sIg densities. Differences in detergent solubility, proteolytic lability, or antisera used also do notmore » adequately account for this difference. Thus, these data indicate that radioactivity incorporated after lactoperoxidase catalyzed cell surface radioiodination may not reflect cell surface Ig density. Conclusions about cell surface density based upon relative incorporation of radioactivity should be confirmed by other approaches.« less

Effect of phospholipid, detergent and protein-protein interaction on stability and phosphoenzyme isomerization of soluble sarcoplasmic reticulum Ca-ATPase.

PubMed

Vilsen, B; Andersen, J P

1987-12-30

The purpose of the present study was to elucidate the separate roles of lipid, detergent and protein-protein interaction for stability and catalytic properties of sarcoplasmic reticulum Ca-ATPase solubilized in the non-ionic detergent octa(ethylene glycol) monododecyl ether (C12E8). The use of large-zone high-performance liquid chromatography permitted us to define the self-association state of Ca-ATPase peptide at various detergent, phospholipid and protein concentrations, and also during enzymatic turnover with ATP. Conditions were established for monomerization of Ca-ATPase in the presence of a high concentration of phospholipid relative to detergent. The lipid-saturated monomeric preparation was relatively resistant to inactivation in the absence of Ca2+, whereas delipidated enzyme in monomeric or in oligomeric form was prone to inactivation. Kinetics of phosphoenzyme turnover were examined in the presence and absence of Mg2+. Dephosphorylation rates were sensitive to Mg2+, irrespective of whether the peptide was present in soluble monomeric form or was membrane-bound. C12E8-solubilized monomer without added phospholipid was, however, characterized by a fast initial phase of dephosphorylation in the absence of Mg2+. This was not observed with monomer saturated with phospholipid or with monomer solubilized in myristoylglycerophosphocholine or deoxycholate. The mechanism underlying this difference was shown to be a C12E8-induced acceleration of conversion of ADP-sensitive phosphoenzyme (E1P) to ADP-insensitive phosphoenzyme (E2P). The phosphoenzyme isomerization rate was also found to be enhanced by low-affinity binding of ATP. This was demonstrated both in membrane-bound and in soluble monomeric Ca-ATPase. Our results indicate that a single peptide chain constitutes the target for modulation of phosphoenzyme turnover by Mg2+ and ATP, and that detergent effects, distinct from those arising from disruption of protein-protein contacts, are the major determinants of kinetic differences between C12E8-solubilized and membrane-bound enzyme preparations.

Microbiological Production of Carotenoids

PubMed Central

Ciegler, Alex; Nelson, George E. N.; Hall, Harlow H.

1962-01-01

Synthesis of β-carotene by mated strains of Blakeslea trispora in shaken-flask culture was considerably enhanced by adding either 5% kerosene after 2 days of fermentation or acid-refined kerosene at the start of fermentation to a grain-based medium that also contained a natural lipid, nonionic detergent, and β-ionone; average yields of 17,500 μg per g of dry fermentation solids (86,000 μg per 100 ml of medium) were attained when refined kerosene was used. Almost all of the carotene was retained within the mycelium. Peak yields were achieved in 5 days. PMID:13879500

Irritant and sensitizing potential of eight surfactants commonly used in skin cleansers: an evaluation of 105 patients.

PubMed

Corazza, Monica; Lauriola, Maria Michela; Bianchi, Anna; Zappaterra, Mario; Virgili, Annarosa

2010-01-01

Irritation from surfactants contained in detergents is a frequent adverse reaction to cosmetics. Sensitization to surfactants is also possible. In the literature, comparative studies about irritant and sensitizing potential of different surfactants are heterogeneous and inconclusive about the best molecules to use. We compared the irritant and sensitizing potential of some surfactants that are usual components in marketed synthetic detergents (syndets) to obtain practical information regarding commonly used detergents. We patch-tested eight surfactants of the different types (anionic, cationic, amphoteric, and non-ionic) in 105 patients. Assessment of allergic reactions of tested surfactants was carried out in accordance with the recommendations of the International Contact Dermatitis Research Group; assessment of irritant power followed the amended Draize classification. None of the eight surfactants in our series gave positive allergic reactions. Only cocamidopropyl betaine from the Italian standard (Società Italiana di Dermatologia Allergologica, Professionale e Ambientale [SIDAPA]) series gave five positive reactions among 105 patients. None of the eight studied surfactants induced skin irritation. The most tolerated are two new mild anionics (sodium cocoyl glutamate and sodium lauroyl oat amino acids) and an amphoteric agent (disodium cocoamphodiacetate). From this study, we deduce that cosmetic companies' efforts to search for and market new products with very mild surfactants have been generally successful.

Evaluation of the biotechnological potential of a novel purified protease BS1 from Bacillus safensis S406 on the chitin extraction and detergent formulation.

PubMed

Mhamdi, Samiha; Bkhairia, Intidhar; Nasri, Rim; Mechichi, Tahar; Nasri, Moncef; Kamoun, Alya Sellami

2017-11-01

An extracellular alkaline stable protease BS1 from a new bacteria strain, Bacillus safensis S406, isolated from the Sfax solar saltern, was purified and characterized. The enzyme was purified to homogeneity by ammonium sulfate precipitation, Sephadex G-75 gel filtration, Mono-Q anion-exchange chromatography and ultrafiltration, with a 12.70-fold increase in specific activity and 20.29% recovery. The enzyme has a molecular weight of 29kDa and appeared as a single band on native-PAGE. The optimum pH and temperature values of its proteolytic activity were pH 11.0 and 60°C, respectively. BS1 was tested for the deproteinization of shrimp wastes to extract chitin. An enzyme-protein ratio of 10U/mg of proteins allows to eliminate 93% of protein linked to the chitin after 3h hydrolysis at 45°C. Being very active in alkaline conditions, the potential application of BS1 in laundry formulation was investigated. The enzyme showed high stability in the presence of non-ionic surfactants and some commercial liquid and solid detergents, suggesting its eventual use in detergent formulations. 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.

Impact of Interfacial Composition on Lipid and Protein Co-Oxidation in Oil-in-Water Emulsions Containing Mixed Emulisifers.

PubMed

Zhu, Zhenbao; Zhao, Cui; Yi, Jianhua; Liu, Ning; Cao, Yuangang; Decker, Eric A; McClements, David Julian

2018-05-02

The impact of interfacial composition on lipid and protein co-oxidation in oil-in-water emulsions containing a mixture of proteins and surfactants was investigated. The emulsions consisted of 5% v/v walnut oil, 0.5% w/v whey protein isolate (WPI), and 0 to 0.4% w/v Tween 20 (pH 3 and pH 7). The protein surface load, magnitude of the ξ-potential, and mean particle diameter of the emulsions decreased as the Tween 20 concentration was increased, indicating the whey proteins were displaced by this nonionic surfactant. The whey proteins were displaced from the lipid droplet surfaces more readily at pH 3 than at pH 7, which may have been due to differences in the conformation or interactions of the proteins at the droplet surfaces at different pH values. Emulsions stabilized by whey proteins alone had relatively low lipid oxidation rates when incubated in the dark at 45 °C for up to 8 days, as determined by measuring lipid hydroperoxides and 2-thiobarbituric acid-reactive substances (TBARS). Conversely, the whey proteins themselves were rapidly oxidized, as shown by carbonyl formation, intrinsic fluorescence, sulfhydryl group loss, and electrophoresis measurements. Displacement of whey proteins from the interface by Tween 20 reduced protein oxidation but promoted lipid oxidation. These results indicated that the adsorbed proteins were more prone to oxidation than the nonadsorbed proteins, and therefore, they could act as better antioxidants. Protein oxidation was faster, while lipid oxidation was slower at pH 3 than at pH 7, which was attributed to a higher antioxidant activity of whey proteins under acidic conditions. These results highlight the importance of interfacial composition and solution pH on the oxidative stability of emulsions containing mixed emulsifiers.

Microbial polychlorinated biphenyl dechlorination in sediments by electrical stimulation: The effect of adding acetate and nonionic surfactant.

PubMed

Yu, Hui; Wan, Hui; Feng, Chunhua; Yi, Xiaoyun; Liu, Xiaoping; Ren, Yuan; Wei, Chaohai

2017-02-15

The necessity for developing an efficient and cost-effective in situ bioremediation technology for sediments contaminated with polychlorinated biphenyls (PCBs) has prompted the application of low-voltage electrical fields to anaerobic digestion systems. Here we show that the use of a sediment-based bio-electrochemical reactor (BER) poised at a potential of -0.50V (vs. a standard calomel electrode, SCE) substantially enhanced the reduction of 2,3,4,5-tetrachlorobiphenyl (PCB 61) when acetate was added as a carbon source. The addition of surfactant Tween 80 to the BER further accelerated the PCB 61 transformation. The comparative study of closed- and open-circuit reactors demonstrated the enrichment conditions affecting the bacterial community structure, the dominant dechlorination metabolisms, and thus the extent, the rate and the products of the reduction of PCBs. The dominant bacterial dechlorinators detected in the BERs in the presence of acetate and Tween 80 are Dehalogenimonas, Dehalobacter, Sulfuricurvum, Dechloromonas and Geobacter, which should be responsible for PCB dechlorination. This study improves understanding of the key factors influencing dechlorination activity in sediment-based BERs polarized at a low potential, as well as the metabolic mechanisms dominating in the PCB dechlorination process. Copyright © 2016 Elsevier B.V. All rights reserved.

Preparation and physicochemical evaluation of emulsified virgin coconut oil (VCO)-carica papaya extract concoction using Tween80

NASA Astrophysics Data System (ADS)

Omar, Hazreen; Zubairi, Saiful Irwan; Fadhilah, Mohd Faizulhelmi; Omar, Dzolkhifli; Asib, Norhayu

2016-11-01

Carica papaya is a member of the Caricaceae. Its leaves have been used in folk medicine for centuries. Recent studies have shown its beneficial effects as an anti-inflammatory agent (Owoyele et al 2008) and anti-tumour15 as well as antioxidant and wound healing properties7. The study has shown that the effect of carica papaya leaves juice intake also can accelerate the rate of increase in platelet count among the patients infected with dengue fever and dengue haemorrhagic fever18. With all the goodness of carica papaya leaves, a formulation with addition of virgin coconut oil (VCO) is produced to give an enhanced supplement beverage to market nowadays. Virgin coconut oil is well known as anti-oxidant4. The combination of these two substances gives a balance combination in healthy supplement. In recent years the application of emulsion is rapidly increasing in many fields such as cosmetics and paints. Emulsions are dispersions of droplets of one liquid in another, immiscible, liquid in which the droplets are of colloidal or near-colloidal sizes. The combination of water and oil (VCO) with addition of non-ionic surfactant Tween80 was constructed using ternary phase diagram. By considering the Hydrophilic-Lipophilic Balance (HLB) value of each substance will help in producing a stable emulsion.

Rheological Properties of Nanoparticle Silica-Surfactant Stabilized Crude Oil Emulsions: Influence of Temperature, Nanoparticle Concentration and Water Volume Fraction"

NASA Astrophysics Data System (ADS)

Kinsey, Erin; Pales, Ashley; Li, Chunyan; Mu, Linlin; Bai, Lingyun; Clifford, Heather; Darnault, Christophe

2016-04-01

Oil in water emulsions occur during oil extraction due to the presence of water, naturally-occurring surface-active agents and mechanical mixing in pipelines or from oil spillage. Emulsions present difficulties for use of oil in fuel and their rheological properties are important to treat environmental impacts of spills. The objective of this study is to assess the rheological characteristics of oil in water emulsions stabilized by 5% NaCl brine, Tween 20 surfactant and silica nanoparticles to gain knowledge about the behavior of oil flow in pipelines and characterize them for environmental applications. Rheological behaviors such as shear rate, shear stress, and viscosity of Prudhoe Bay crude oil emulsions were analyzed with varying percent of water volume fractions (12.5, 25 and 50%), varying weight percent of silica nanoparticles (0.001, 0.01 and 0.1 weight %), with and without 2 CMC Tween 20 nonionic surfactant. Emulsions with varying water volume fractions were analyzed at 20, 40 and 60 degrees Celsius. Flow curve analysis of the emulsions was performed using an Anton-Paar rheometer. Preliminary findings indicate that increased temperature and increasing the concentration of nanoparticles both produced lower shear stress and that the addition of surfactant decreased the viscosity and shear stress of the emulsions.

Surfactants have multi-fold effects on skin barrier function.

PubMed

Lemery, Emmanuelle; Briançon, Stéphanie; Chevalier, Yves; Oddos, Thierry; Gohier, Annie; Boyron, Olivier; Bolzinger, Marie-Alexandrine

2015-01-01

The stratum corneum (SC) is responsible for the barrier properties of the skin and the role of intercorneocyte skin lipids, particularly their structural organization, in controlling SC permeability is acknowledged. Upon contacting the skin, surfactants interact with the SC components leading to barrier damage. To improve knowledge of the effect of several classes of surfactant on skin barrier function at three different levels. The influence of treatments of human skin explants with six non-ionic and four ionic surfactant solutions on the physicochemical properties of skin was investigated. Skin surface wettability and polarity were assessed through contact angle measurements. Infrared spectroscopy allowed monitoring the SC lipid organization. The lipid extraction potency of surfactants was evaluated thanks to HPLC-ELSD assays. One anionic and one cationic surfactant increased the skin polarity by removing the sebaceous and epidermal lipids and by disturbing the organization of the lipid matrix. Another cationic surfactant displayed a detergency effect without disturbing the skin barrier. Several non-ionic surfactants disturbed the lipid matrix organization and modified the skin wettability without any extraction of the skin lipids. Finally two non-ionic surfactants did not show any effect on the investigated parameters or on the skin barrier. The polarity, the organization of the lipid matrix and the lipid composition of the skin allowed describing finely how surfactants can interact with the skin and disturb the skin barrier function.

Cloning and enhancing production of a detergent- and organic-solvent-resistant nattokinase from Bacillus subtilis VTCC-DVN-12-01 by using an eight-protease-gene-deficient Bacillus subtilis WB800

PubMed Central

2013-01-01

Background Nattokinases/Subtilisins (EC 3.4.21.62) belong to the second large family of serine proteases, which gain significant attention and play important role in many biotechnology processes. Thus, a number of nattokinases/subtilisins from various Bacillus species, especially from B. subtilis strains, extensively have been investigated to understand their biochemical and physical properties as well as to improve the production for industrial application. The purpose of this study was to clone a nattokinase gene from Bacillus subtilis strain VTCC-DVN-12-01, enhance its production in B. subtilis WB800, which is deficient in eight extracellular proteases and characterize its physicochemical properties for potential application in organic synthesis and detergent production. Results A gene coding for the nattokinase (Nk) from B. subtilis strain VTCC-DVN-12-01 consisted of an ORF of 1146 nucleotides, encoding a pre-pro-protein enzyme (30-aa pre-signal peptide, 76-aa pro-peptide and 275-aa mature protein with a predicted molecular mass of 27.7 kDa and pI 6.6). The nattokinase showed 98-99% identity with other nattokinases/subtilisins from B. subtilis strains in GenBank. Nk was expressed in B. subtilis WB800 under the control of acoA promoter at a high level of 600 mg protein per liter culture medium which is highest yield of proteins expressed in any extracellular-protease-deficient B. subtilis system till date. Nk was purified to homogeneity with 3.25 fold purification, a specific activity of 12.7 U/mg, and a recovery of 54.17%. The purified Nk was identified by MALDI-TOF mass spectrometry through three peptides, which showed 100% identity to corresponding peptides of the B. subtilis nattokinase (CAC41625). An optimal activity for Nk was observed at 65°C and pH 9. The nattokinase was stable at temperature up to 50°C and in pH range of 5–11 and retained more than 85% of its initial activity after incubation for 1 h. Mg2+ activated Nk up to 162% of its activity. The addition of Triton X-100, Tween 20, and Tween 80 showed an activation of Nk up to 141% of its initial activity but SDS strongly inhibited. The enzyme was highly resistant to organic solvents. Conclusions Our findings demonstrated that an eight-protease-gene-deficient Bacillus subtilis WB800 could overproduce the nattokinase from B. subtilis VTCC-DVN-12-01. Due to high resistance to detergents and organic solvents of this nattokinase, it could be potentially applied in organic synthesis and detergent production. PMID:24021098

Cloning and enhancing production of a detergent- and organic-solvent-resistant nattokinase from Bacillus subtilis VTCC-DVN-12-01 by using an eight-protease-gene-deficient Bacillus subtilis WB800.

PubMed

Nguyen, Thao Thi; Quyen, Thi Dinh; Le, Hoang Thanh

2013-09-10

Nattokinases/Subtilisins (EC 3.4.21.62) belong to the second large family of serine proteases, which gain significant attention and play important role in many biotechnology processes. Thus, a number of nattokinases/subtilisins from various Bacillus species, especially from B. subtilis strains, extensively have been investigated to understand their biochemical and physical properties as well as to improve the production for industrial application. The purpose of this study was to clone a nattokinase gene from Bacillus subtilis strain VTCC-DVN-12-01, enhance its production in B. subtilis WB800, which is deficient in eight extracellular proteases and characterize its physicochemical properties for potential application in organic synthesis and detergent production. A gene coding for the nattokinase (Nk) from B. subtilis strain VTCC-DVN-12-01 consisted of an ORF of 1146 nucleotides, encoding a pre-pro-protein enzyme (30-aa pre-signal peptide, 76-aa pro-peptide and 275-aa mature protein with a predicted molecular mass of 27.7 kDa and pI 6.6). The nattokinase showed 98-99% identity with other nattokinases/subtilisins from B. subtilis strains in GenBank. Nk was expressed in B. subtilis WB800 under the control of acoA promoter at a high level of 600 mg protein per liter culture medium which is highest yield of proteins expressed in any extracellular-protease-deficient B. subtilis system till date. Nk was purified to homogeneity with 3.25 fold purification, a specific activity of 12.7 U/mg, and a recovery of 54.17%. The purified Nk was identified by MALDI-TOF mass spectrometry through three peptides, which showed 100% identity to corresponding peptides of the B. subtilis nattokinase (CAC41625). An optimal activity for Nk was observed at 65 °C and pH 9. The nattokinase was stable at temperature up to 50 °C and in pH range of 5-11 and retained more than 85% of its initial activity after incubation for 1 h. Mg2+ activated Nk up to 162% of its activity. The addition of Triton X-100, Tween 20, and Tween 80 showed an activation of Nk up to 141% of its initial activity but SDS strongly inhibited. The enzyme was highly resistant to organic solvents. Our findings demonstrated that an eight-protease-gene-deficient Bacillus subtilis WB800 could overproduce the nattokinase from B. subtilis VTCC-DVN-12-01. Due to high resistance to detergents and organic solvents of this nattokinase, it could be potentially applied in organic synthesis and detergent production.

Polyhydroxyalkanoate synthesis in transgenic plants as a new tool to study carbon flow through beta-oxidation.

PubMed

Mittendorf, V; Bongcam, V; Allenbach, L; Coullerez, G; Martini, N; Poirier, Y

1999-10-01

Transgenic plants producing peroxisomal polyhydroxy- alkanoate (PHA) from intermediates of fatty acid degradation were used to study carbon flow through the beta-oxidation cycle. Growth of transgenic plants in media containing fatty acids conjugated to Tween detergents resulted in an increased accumulation of PHA and incorporation into the polyester of monomers derived from the beta-oxidation of these fatty acids. Tween-laurate was a stronger inducer of beta-oxidation, as measured by acyl-CoA oxidase activity, and a more potent modulator of PHA quantity and monomer composition than Tween-oleate. Plants co-expressing a peroxisomal PHA synthase with a capryl-acyl carrier protein thioesterase from Cuphea lanceolata produced eightfold more PHA compared to plants expressing only the PHA synthase. PHA produced in double transgenic plants contained mainly saturated monomers ranging from 6 to 10 carbons, indicating an enhanced flow of capric acid towards beta-oxidation. Together, these results support the hypothesis that plant cells have mechanisms which sense levels of free or esterified unusual fatty acids, resulting in changes in the activity of the beta-oxidation cycle as well as removal and degradation of these unusual fatty acids through beta-oxidation. Such enhanced flow of fatty acids through beta-oxidation can be utilized to modulate the amount and composition of PHA produced in transgenic plants. Furthermore, synthesis of PHAs in plants can be used as a new tool to study the quality and relative quantity of the carbon flow through beta-oxidation as well as to analyse the degradation pathway of unusual fatty acids.

Effects of silica-based nanostructures with raspberry-like morphology and surfactant on the interfacial behavior of light, medium, and heavy crude oils at oil-aqueous interfaces

NASA Astrophysics Data System (ADS)

Bai, Lingyun; Li, Chunyan; Korte, Caroline; Huibers, Britta M. J.; Pales, Ashley R.; Liang, Wei-zhen; Ladner, David; Daigle, Hugh; Darnault, Christophe J. G.

2017-11-01

Any efficient exploitation of new petroleum reservoirs necessitates developing methods to mobilize the crude oils from such reservoirs. Here silicon dioxide nanoparticles (SiO2 NPs) were used to improve the efficiency of the chemical-enhanced oil recovery process that uses surfactant flooding. Specifically, SiO2 NPs (i.e., 0, 0.001, 0.005, 0.01, 0.05, and 0.1 wt%) and Tween®20, a nonionic surfactant, at 0, 0.5, and 2 critical micelle concentration (CMC) were varied to determine their effect on the stability of nanofluids and the interfacial tension (IFT) at the oil-aqueous interface for 5 wt% brine-surfactant-SiO2 nanofluid-oil systems for West Texas Intermediate light crude oil, Prudhoe Bay medium crude oil, and Lloydminster heavy crude oil. Our study demonstrates that SiO2 NPs may either decrease, increase the IFT of the brine-surfactant-oil systems, or exhibit no effects at all. For the brine-surfactant-oil systems, the constituents of the oil and aqueous substances affected the IFT behavior, with the nanoparticles causing a contrast in IFT trends according to the type of crude oil. For the light oil system (0.5 and 2 CMC Tween®20), the IFT increased as a function of SiO2 NP concentration, while a threshold concentration of SiO2 NPs was observed for the medium (0.5 and 2 CMC Tween®20) and heavy (2 CMC Tween®20) oil systems in terms of IFT trends. Concentrations below the SiO2 NP threshold concentration resulted in a decrease in IFT, and concentrations above this threshold resulted in an increase in IFT. The IFT decreased until the NP concentration reached a threshold concentration where synergetic effects between nonionic surfactants and SiO2 NPs are the opposite and result in antagonistic effects. Adsorption of both SiO2 NPs and surfactants at an interface caused a synergistic effect and an increased reduction in IFT. The effectiveness of the brine-surfactant-SiO2 nanofluids in decreasing the IFT between the oil-aqueous phase for the three tested crude oils were ranked as follows: (1) Prudhoe Bay > (2) Lloydminster > and (3) West Texas Intermediate. The level of asphaltenes and resins in these crude oil samples reflected these rankings. A decrease in the IFT also indicated the potential of the SiO2 NPs to decrease capillary pressure and induce the movement and recovery of oil in original water-wet reservoirs. Conversely, an increase in IFT indicated the potential of SiO2 NPs to increase capillary pressure and oil recovery in reservoirs subject to wettability reversal under water-wet conditions. Raspberry-like morphology particles were discovered in 5 wt% brine-surfactant-SiO2 nanofluid-oil systems. The development of raspberry-like particles material with high surface area, high salt stability, and high capability of interfaces alteration and therefore wettability changes offers a wide range of applications in the fields of applied nanoscience, environmental engineering, and petroleum engineering.

Efficacy of detergents in removing Salmonella and Shigella spp. from the surface of fresh produce.

PubMed

Raiden, Renee M; Sumner, Susan S; Eifert, Joseph D; Pierson, Merle D

2003-12-01

Fresh produce has been implicated in several foodborne disease outbreaks. Produce surfaces can be primary sites of contamination during production and handling. One approach to reduce contamination is to treat fresh produce with rinsing agents. In this study, different detergent agents were used at 22 and 40 degrees C to determine their efficacy in removing Salmonella and Shigella spp. from the surfaces of strawberries, tomatoes, and green-leaf lettuce. Produce was inoculated at 22 degrees C with a cocktail of nalidixic acid-resistant organisms (6 to 6.5 log CFU/ml). After air drying for 1 h, samples were rinsed with either 0.1% Tween 80, 0.1% sodium lauryl sulfate (SLS), or water (control) at 22 or 40 degrees C. Rinse solutions were spiral plated onto tryptic soy agar supplemented with 50 mg of nalidixic acid per liter. In trials involving strawberries and lettuce, Salmonella and Shigella were removed at levels of 4 and 3 log CFU/ml, respectively, except from Salmonella-inoculated strawberries rinsed with SLS, for which minimal removal rates were 1.5 log CFU/ml at 22 degrees C and < 1 log CFU/ml at 40 degrees C. When whole strawberries were analyzed after rinsing with SLS, few organisms were recovered. This result suggests that SLS may have a lethal or sublethal effect on Salmonella, especially when a 40 degrees C solution is used. Salmonella and Shigella removal rates for tomatoes were 1 and 1.5 log CFU/ml lower, respectively, than those for strawberries or lettuce. Overall, detergents were no more effective in removing organisms from produce than water was. The detergents examined would not constitute effective overall produce rinse treatments.

Production, characterization, and immobilization of partially purified surfactant-detergent and alkali-thermostable protease from newly isolated Aeromonas caviae.

PubMed

Datta, Sumitra; Menon, Gopalakrishnan; Varughese, Bincy

2017-04-21

Proteolytic Aeromonas caviae P-1-1 growing at wide-ranging pH (7.0-11.0) and moderate salinity (0-5% NaCl) was isolated from cattle shed of Thanjavur, India. It produced lipase, gelatinase, and polyhydroxybutyrate. Different culture conditions, incubation time, carbon and nitrogen sources, vitamins, amino acids, surfactants, and metal ions for optimal growth and protease production of P-1-1 were examined. Maximum protease (0.128 U/mL) production was achieved with 1% fructose, 1% yeast extract, 0.1% ammonium sulfate, 3% NaCl, 0.1% CaCl 2  · 2H 2 O, 1% glycine, 0.1% vitamin E, and 0.1% Tween-40 at pH 8.0 after 42 hr of incubation at 37°C. It was active over broad range of pH (7.0-12.0), temperature (15-100°C), and salinity (0-9% NaCl) with optima at pH 10.0, 55°C, and 3% NaCl. It retained 65 and 48% activities at pH 12.0 and 100°C, respectively. Partially purified protease was highly stable (100%) within pH range 7.0-12.0 and salinities of 0-5% NaCl for 48 hr. Cu 2+ , Mn 2+ , Co 2+ , and Ca 2+ did not inhibit its activity. Its stability at extreme pHs, temperatures, and in the presence of surfactants and commercial detergents suggests its possible application in laundry detergents. Partially purified protease was immobilized and reused. This is the first report of alkali-thermotolerant, surfactant-detergent-stable partially purified extracellular protease from A. caviae.

Growth of wormlike micelles in nonionic surfactant solutions: Quantitative theory vs. experiment.

PubMed

Danov, Krassimir D; Kralchevsky, Peter A; Stoyanov, Simeon D; Cook, Joanne L; Stott, Ian P; Pelan, Eddie G

2018-06-01

Despite the considerable advances of molecular-thermodynamic theory of micelle growth, agreement between theory and experiment has been achieved only in isolated cases. A general theory that can provide self-consistent quantitative description of the growth of wormlike micelles in mixed surfactant solutions, including the experimentally observed high peaks in viscosity and aggregation number, is still missing. As a step toward the creation of such theory, here we consider the simplest system - nonionic wormlike surfactant micelles from polyoxyethylene alkyl ethers, C i E j . Our goal is to construct a molecular-thermodynamic model that is in agreement with the available experimental data. For this goal, we systematized data for the micelle mean mass aggregation number, from which the micelle growth parameter was determined at various temperatures. None of the available models can give a quantitative description of these data. We constructed a new model, which is based on theoretical expressions for the interfacial-tension, headgroup-steric and chain-conformation components of micelle free energy, along with appropriate expressions for the parameters of the model, including their temperature and curvature dependencies. Special attention was paid to the surfactant chain-conformation free energy, for which a new more general formula was derived. As a result, relatively simple theoretical expressions are obtained. All parameters that enter these expressions are known, which facilitates the theoretical modeling of micelle growth for various nonionic surfactants in excellent agreement with the experiment. The constructed model can serve as a basis that can be further upgraded to obtain quantitative description of micelle growth in more complicated systems, including binary and ternary mixtures of nonionic, ionic and zwitterionic surfactants, which determines the viscosity and stability of various formulations in personal-care and house-hold detergency. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

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

Atypical effects of incorporated surfactants on stability and dissolution properties of amorphous polymeric dispersions.

PubMed

Al-Obaidi, Hisham; Lawrence, M Jayne; Buckton, Graham

2016-11-01

To understand the impact of ionic and non-ionic surfactants on the dissolution and stability properties of amorphous polymeric dispersions using griseofulvin (GF) as a model for poorly soluble drugs. Solid dispersions of the poorly water-soluble drug, griseofulvin (GF) and the polymers, poly(vinylpyrrolidone) (PVP) and poly(2-hydroxypropyl methacrylate) (PHPMA), have been prepared by spray drying and bead milling and the effect of the ionic and non-ionic surfactants, namely sodium dodecyl sulphate (SDS) and Tween-80, on the physico-chemical properties of the solid dispersions studied. The X-ray powder diffraction data and hot-stage microscopy showed a fast re-crystallisation of GF. While dynamic vapour sorption (DVS) measurements indicated an increased water uptake, slow dissolution rates were observed for the solid dispersions incorporating surfactants. The order by which surfactants free dispersions were prepared seemed critical as indicated by DVS and thermal analysis. Dispersions prepared by milling with SDS showed significantly better stability than spray-dried dispersions (drug remained amorphous for more than 6 months) as well as improved dissolution profile. We suggest that surfactants can hinder the dissolution by promoting aggregation of polymeric chains, however that effect depends mainly on how the particles were prepared. © 2016 Royal Pharmaceutical Society.

Impact of electrochemical treatment of soil washing solution on PAH degradation efficiency and soil respirometry.

PubMed

Mousset, Emmanuel; Huguenot, David; van Hullebusch, Eric D; Oturan, Nihal; Guibaud, Gilles; Esposito, Giovanni; Oturan, Mehmet A

2016-04-01

The remediation of a genuinely PAH-contaminated soil was performed, for the first time, through a new and complete investigation, including PAH extraction followed by advanced oxidation treatment of the washing solution and its recirculation, and an analysis of the impact of the PAH extraction on soil respirometry. The study has been performed on the remediation of genuine PAH-contaminated soil, in the following three steps: (i) PAH extraction with soil washing (SW) techniques, (ii) PAH degradation with an electro-Fenton (EF) process, and (iii) recirculation of the partially oxidized effluent for another SW cycle. The following criteria were monitored during the successive washing cycles: PAH extraction efficiency, PAH oxidation rates and yields, extracting agent recovery, soil microbial activity, and pH of soil. Two representative extracting agents were compared: hydroxypropyl-beta-cyclodextrin (HPCD) and a non-ionic surfactant, Tween(®) 80. Six PAH with different numbers of rings were monitored: acenaphthene (ACE), phenanthrene (PHE), fluoranthene (FLA), pyrene (PYR), benzo(a)pyrene (BaP), and benzo(g,h,i)perylene (BghiP). Tween(®) 80 showed much better PAH extraction efficiency (after several SW cycles) than HPCD, regardless of the number of washing cycles. Based on successive SW experiments, a new mathematical relation taking into account the soil/water partition coefficient (Kd*) was established, and could predict the amount of each PAH extracted by the surfactant with a good correlation with experimental results (R(2) > 0.975). More HPCD was recovered (89%) than Tween(®) 80 (79%), while the monitored pollutants were completely degraded (>99%) after 4 h and 8 h, respectively. Even after being washed with partially oxidized solutions, the Tween(®) 80 solutions extracted significantly more PAH than HPCD and promoted better soil microbial activity, with higher oxygen consumption rates. Moreover, neither the oxidation by-products nor the acidic media (pH approximately 3) of the partially oxidized solution inhibited the general soil microbial activity during the washing cycle. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of mercury chloride and methyl mercury on brain microsomal Na+-K+-ATPase after partial delipidisation with Lubrol.

PubMed

Magour, S; Mäser, H; Greim, H

1987-03-01

The microsomal Na+-K+-ATPase of rat brain was inhibited by mercury chloride and methyl mercury. The IC50 was 6.5 X 10(-7) M for mercury chloride and 3.5 X 10(-6) M for methyl mercury. The inhibition was of a non-competitive type with respect to ATP. The non-ionic detergent Lubrol potentiated the inhibitory effect of both mercurials. It is concluded that Lubrol removes the bulk lipids present outside the catalytic center of the enzyme. Consequently, the enzyme will become more sensitive to the inhibition by both mercurials.

Delipidation of Cytochrome c Oxidase from Rhodobacter sphaeroides Destabilizes its Quaternary Structure

PubMed Central

Musatov, Andrej; Varhač, Rastislav; Hosler, Jonathan P.; Sedlák, Erik

2016-01-01

Delipidation of detergent-solubilized cytochrome c oxidase isolated from Rhodobacter sphaeroides (Rbs-CcO) has no apparent structural and/or functional effect on the protein, however affects its resistance against thermal or chemical denaturation. Phospholipase A2 (PLA2) hydrolysis of phospholipids that are co-purified with the enzyme removes all but two tightly bound phosphatidylethanolamines. Replacement of the removed phospholipids with nonionic detergent decreases both thermal stability of the enzyme and its resilience against the effect of chemical denaturants such as urea. In contrast to nondelipidated Rbs-CcO, the enzymatic activity of PLA2-treated Rbs-CcO is substantially diminished after exposure to high (>4M) urea concentration at room temperature without an alteration of its secondary structure. Absorbance spectroscopy and sedimentation velocity experiments revealed a strong correlation between intact tertiary structure of heme regions and quaternary structure, respectively, and the enzymatic activity of the protein. We concluded that phospholipid environment of Rbs-CcO has the protective role for stability of its tertiary and quaternary structures. PMID:26923069

Synthesis and toxicity test of magnetic nanoparticle via biocompatible microemulsion system as template for application in targeted drug delivery

NASA Astrophysics Data System (ADS)

Kader, Razinah Abdul; Rose, Laili Che; Suhaimi, Hamdan; Manickam, Mariessa Soosai

2017-09-01

This work reports the preparation of magnetic nanoparticles (FeNPs) using biocompatible W/O microemulsion for biomedical applications. W/O microemulsion was formed using decane as oil phase, water, tween 80 as non-ionic surfactant and hexanol as organic solvent. The synthesized FeNPs were characterised by using Fourier Transform Infrared Resonance Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The FTIR showed that Fe-O bond exist on 581cm-1 having strong magnetic strength whereas SEM showed the morphology surface of magnetic nanoparticles (FeNPs). Furthermore, analysis of XRD pattern magnetic nanoparticles (FeNPs) reveals a cubic iron oxide phase with good crystallize structure. Furthermore, toxicity test on human liver cells proved that it is 70% safe on human and proved to be a safety nanomedicine.

Characterization of violaxanthin de-epoxidase purified in the presence of Tween 20: effects of dithiothreitol and pepstatin A.

PubMed

Kuwabara, T; Hasegawa, M; Kawano, M; Takaichi, S

1999-11-01

Violaxanthin de-epoxidase (VDE) was purified from thylakoid membranes of spinach by conventional column chromatography in the presence of Tween 20. The neutral detergent was necessary to prevent non-specific interaction of VDE with column resins. In anion-exchange chromatography on Mono Q, VDE appeared in two peaks. Both peaks exhibited a polypeptide of 41 kDa when fully reduced with 5 mM dithiothreitol. Re-chromatography of either peak gave rise to both peaks, suggesting that the two forms of VDE are interconvertible. VDE characteristically changed its electrophoretic mobility depending on the concentration of dithiothreitol with which the protein was treated. When non-reduced, it showed two polypeptides of 43 and 42 kDa. These polypeptides moved down to the position of 40 kDa, and then up to the position of 41 kDa, along with the increase in the dithiothreitol concentration from 0 to 2 mM. These findings suggest that VDE has more than one disulfide bond and takes multiple forms depending on the extent of the reduction. Studies with various types of protein-modifying reagent revealed that VDE is sensitive to pepstatin A, a specific inhibitor of aspartic protease. This finding suggests that the reaction center of VDE contains a reactive aspartic acid residue(s).

Reversal of multidrug resistance by surfactants.

PubMed Central

Woodcock, D. M.; Linsenmeyer, M. E.; Chojnowski, G.; Kriegler, A. B.; Nink, V.; Webster, L. K.; Sawyer, W. H.

1992-01-01

Cremophor EL, a pharmacologically inactive solubilising agent, has been shown to reverse multidrug resistance (MDR). Using flow cytometric evaluation of equilibrium intracellular levels of daunorubicin (DNR), we found that eight other surface active agents will also reverse MDR. All the active detergents contain polyethoxylated moieties but have no similarities in their hydrophobic components. The properties of three polyethoxylated surfactants that showed the lowest toxicities, Cremophor, Tween 80 and Solutol HS15, were examined in more detail. The concentrations of Tween 80 and Solutol required to reverse DNR exclusion were 10-fold lower than for Cremophor. However while concentrations greater than or equal to 1:10(2) of the former two surfactants resulted in breakdown of cells, even 1:10 of Cremophor did not lyse cells. Studies of the effects of Cremophor on the uptake and efflux of DNR in normal and MDR cell types showed that Cremophor increases intracellular DNR primarily by locking the rapid efflux from the cells. This blockage of drug efflux may be mediated by a substantial alteration in the fluidity of cell membranes induced by Cremophor, as shown by decreased fluorescence anisotropy of a membrane probe. Consistent with these data, coinjection of adriamycin plus Cremophor into mice carrying a multidrug resistant P388 transplantable tumour significantly increased the survival time of the mice compared with adriamycin treatment alone. PMID:1637678

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

Proteomic Analysis of Detergent-resistant Membrane Microdomains in Trophozoite Blood Stage of the Human Malaria Parasite Plasmodium falciparum*

PubMed Central

Yam, Xue Yan; Birago, Cecilia; Fratini, Federica; Di Girolamo, Francesco; Raggi, Carla; Sargiacomo, Massimo; Bachi, Angela; Berry, Laurence; Fall, Gamou; Currà, Chiara; Pizzi, Elisabetta; Breton, Catherine Braun; Ponzi, Marta

2013-01-01

Intracellular pathogens contribute to a significant proportion of infectious diseases worldwide. The successful strategy of evading the immune system by hiding inside host cells is common to all the microorganism classes, which exploit membrane microdomains, enriched in cholesterol and sphingolipids, to invade and colonize the host cell. These assemblies, with distinct biochemical properties, can be isolated by means of flotation in sucrose density gradient centrifugation because they are insoluble in nonionic detergents at low temperature. We analyzed the protein and lipid contents of detergent-resistant membranes from erythrocytes infected by Plasmodium falciparum, the most deadly human malaria parasite. Proteins associated with membrane microdomains of trophic parasite blood stages (trophozoites) include an abundance of chaperones, molecules involved in vesicular trafficking, and enzymes implicated in host hemoglobin degradation. About 60% of the identified proteins contain a predicted localization signal suggesting a role of membrane microdomains in protein sorting/trafficking. To validate our proteomic data, we raised antibodies against six Plasmodium proteins not characterized previously. All the selected candidates were recovered in floating low-density fractions after density gradient centrifugation. The analyzed proteins localized either to internal organelles, such as the mitochondrion and the endoplasmic reticulum, or to exported membrane structures, the parasitophorous vacuole membrane and Maurer's clefts, implicated in targeting parasite proteins to the host erythrocyte cytosol or surface. The relative abundance of cholesterol and phospholipid species varies in gradient fractions containing detergent-resistant membranes, suggesting heterogeneity in the lipid composition of the isolated microdomain population. This study is the first report showing the presence of cholesterol-rich microdomains with distinct properties and subcellular localization in trophic stages of Plasmodium falciparum. PMID:24045696

Vaginal microbicides: detecting toxicities in vivo that paradoxically increase pathogen transmission

PubMed Central

Cone, Richard A; Hoen, Timothy; Wong, XiXi; Abusuwwa, Raed; Anderson, Deborah J; Moench, Thomas R

2006-01-01

Background Microbicides must protect against STD pathogens without causing unacceptable toxic effects. Microbicides based on nonoxynol-9 (N9) and other detergents disrupt sperm, HSV and HIV membranes, and these agents are effective contraceptives. But paradoxically N9 fails to protect women against HIV and other STD pathogens, most likely because it causes toxic effects that increase susceptibility. The mouse HSV-2 vaginal transmission model reported here: (a) Directly tests for toxic effects that increase susceptibility to HSV-2, (b) Determines in vivo whether a microbicide can protect against HSV-2 transmission without causing toxicities that increase susceptibility, and (c) Identifies those toxic effects that best correlate with the increased HSV susceptibility. Methods Susceptibility was evaluated in progestin-treated mice by delivering a low-dose viral inoculum (0.1 ID50) at various times after delivering the candidate microbicide to detect whether the candidate increased the fraction of mice infected. Ten agents were tested – five detergents: nonionic (N9), cationic (benzalkonium chloride, BZK), anionic (sodium dodecylsulfate, SDS), the pair of detergents in C31G (C14AO and C16B); one surface active agent (chlorhexidine); two non-detergents (BufferGel®, and sulfonated polystyrene, SPS); and HEC placebo gel (hydroxyethylcellulose). Toxic effects were evaluated by histology, uptake of a 'dead cell' dye, colposcopy, enumeration of vaginal macrophages, and measurement of inflammatory cytokines. Results A single dose of N9 protected against HSV-2 for a few minutes but then rapidly increased susceptibility, which reached maximum at 12 hours. When applied at the minimal concentration needed for brief partial protection, all five detergents caused a subsequent increase in susceptibility at 12 hours of ~20–30-fold. Surprisingly, colposcopy failed to detect visible signs of the N9 toxic effect that increased susceptibility at 12 hours. Toxic effects that occurred contemporaneously with increased susceptibility were rapid exfoliation and re-growth of epithelial cell layers, entry of macrophages into the vaginal lumen, and release of one or more inflammatory cytokines (Il-1β, KC, MIP 1α, RANTES). The non-detergent microbicides and HEC placebo caused no significant increase in susceptibility or toxic effects. Conclusion This mouse HSV-2 model provides a sensitive method to detect microbicide-induced toxicities that increase susceptibility to infection. In this model, there was no concentration at which detergents provided protection without significantly increasing susceptibility. PMID:16740164

The mouse neuronal cell surface protein F3: a phosphatidylinositol- anchored member of the immunoglobulin superfamily related to chicken contactin

PubMed Central

1989-01-01

Several members of the Ig superfamily are expressed on neural cells where they participate in surface interactions between cell bodies and processes. Their Ig domains are more closely related to each other than to Ig variable and constant domains and have been grouped into the C2 set. Here, we report the cloning and characterization of another member of this group, the mouse neuronal cell surface antigen F3. The F3 cDNA sequence contains an open reading frame that could encode a 1,020-amino acid protein consisting of a signal sequence, six Ig-like domains of the C2 type, a long premembrane region containing two segments that exhibit sequence similarity to fibronectin type III repeats and a moderately hydrophobic COOH-terminal sequence. The protein does not contain a typical transmembrane segment but appears to be attached to the membrane by a phosphatidylinositol anchor. Antibodies against the F3 protein recognize a prominent 135-kD protein in mouse brain. In fetal brain cultures, they stain the neuronal cell surface and, in cultures maintained in chemically defined medium, most prominently neurites and neurite bundles. The mouse f3 gene maps to band F of chromosome 15. The gene transcripts detected in the brain by F3 cDNA probes are developmentally regulated, the highest amounts being expressed between 1 and 2 wk after birth. The F3 nucleotide and deduced amino acid sequence show striking similarity to the recently published sequence of the chicken neuronal cell surface protein contactin. However, there are important differences between the two molecules. In contrast to F3, contactin has a transmembrane and a cytoplasmic domain. Whereas contactin is insoluble in nonionic detergent and is tightly associated with the cytoskeleton, about equal amounts of F3 distribute between buffer-soluble, nonionic detergent-soluble, and detergent- insoluble fractions. Among other neural cell surface proteins, F3 most resembles the neuronal cell adhesion protein L1, with 25% amino acid identity between their extracellular domains. Based on its structural similarity with known cell adhesion proteins of nervous tissue and with L1 in particular, we propose that F3 mediates cell surface interactions during nervous system development. PMID:2474555

Novel method of niosome generation using supercritical carbon dioxide part I: process mechanics.

PubMed

Wagner, Michael E; Rizvi, Syed S H

2015-01-01

A novel method for the production of non-ionic surfactant vesicles (niosomes) using an rapid expansion of supercritical solution (RESS)-based process coupled with a gas ejector is presented along with an investigation of parameters affecting niosome morphology, size and encapsulation efficiency of a 0.2 M D-glucose solution in Tris buffer at physiological pH. The solubility of the non-ionic surfactant polyoxyethylene(4) sorbitan monostearate in SC-CO2 was determined at three pressures (10, 15 and 20 MPa) and three temperatures (40, 50 and 60 °C). Mole fraction of Tween61 in the vapor phase increased with pressure at 40 °C, but did not change with pressure at 50 or 60 °C. Solubility data were correlated using the Peng-Robinson equation of state (PREOS) with the Panagiotopoulos and Reid mixing rule. Vesicles were either multilamellar or unilamellar, depending on the degree of precipitation of the lipid formulation at the point of aqueous cargo introduction. Vesicle particle size distributions were bimodal, with the 80-99% of the liposomal volume contributed niosomes ranging in size from 3 to 7 μm and the remaining niosomes ranging from 239 to 969 nm, depending on the system configuration. Encapsulation efficiency as high as 28% using the gas ejector to introduce the glucose cargo solution was achieved. Vesicle particle size and encapsulation efficiency were shown to be dependent on cargo droplet formation.

Effect of selected non-ionic surfactants on the flow behavior of aqueous veegum suspensions.

PubMed

Kennedy, Ross A; Kennedy, Michelle L

2007-03-30

The aim of this work was to investigate the influence of some non-ionic surfactants, Tween 80 and Brij 98, on the viscosity and flow behavior of a commercial montmorillonite clay, Veegum Granules. The effect of different concentrations of the surfactants on the shear stress-shear rate rheograms of hydrated concentrated clay suspensions was determined by shear viscometry. The addition of either surfactant increased the plastic viscosity and the yield stress of the suspensions. Furthermore, both surfactants altered the thixotropy of the suspensions to an extent that depended on both the surfactant concentration and the time of equilibration of the surfactant and Veegum. Brij 98 had a greater and more rapid effect. It is proposed that the surfactant polar head-groups anchor at the tetrahedral sheet surface, leaving the alkyl chains extending away from the edges and faces. Consequently, the alkyl chains undergo hydrophobic interactions that facilitate the association between the platelets and increase the physical structure within the suspension. Stereochemical differences between the polar groups may lead to differences in the way the surfactants associate with the tetrahedral sheet and hence their ultimate effect on the rheological behavior. There is a significant interaction between these surfactants and montmorillonite clays, and the rheological changes that occur could have a major impact on any pharmaceutical formulation that uses these ingredients.

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.

Immunochromatographic assay using gold nanoparticles for measuring salivary secretory IgA in dogs as a stress marker

NASA Astrophysics Data System (ADS)

Takahashi, Aki; Uchiyama, Shigeru; Kato, Yuya; Yuhi, Teruko; Ushijima, Hiromi; Takezaki, Makoto; Tominaga, Toshihiro; Moriyama, Yoshiko; Takeda, Kunio; Miyahara, Toshiro; Nagatani, Naoki

2009-06-01

The concentration of salivary secretory immunoglobulin A (sIgA) is a well-known stress marker for humans. The concentration of salivary sIgA in dogs has also been reported as a useful stress marker. In addition, salivary sIgA in dogs has been used to determine the adaptive ability of dogs for further training. There are conventional procedures based on enzyme-linked immunosorbent assay (ELISA) for measuring salivary sIgA in dogs. However, ELISA requires long assay time, complicated operations and is costly. In the present study, we developed an immunochromatographic assay for measuring salivary sIgA in dogs using a dilution buffer containing a non-ionic surfactant. We determined 2500-fold dilution as the optimum condition for dog saliva using a phosphate buffer (50 mM, pH 7.2) containing non-ionic surfactant (3 wt% Tween 20). The results obtained from the saliva samples of three dogs using immunochromatographic assay were compared with those obtained from ELISA. It was found that the immunochromatographic assay is applicable to judge the change in salivary sIgA in each dog. The immunochromatographic assay for salivary sIgA in dogs is a promising tool, which should soon become commercially available for predicting a dog's psychological condition and estimating adaptive ability for training as guide or police dogs.

Micro-porous surfaces in controlled drug delivery systems: design and evaluation of diltiazem hydrochloride controlled porosity osmotic pump using non-ionic surfactants as pore-former.

PubMed

Adibkia, Khosro; Ghanbarzadeh, Saeed; Shokri, Mohammad Hosein; Arami, Zahra; Arash, Zeinab; Shokri, Javad

2014-06-01

The major problem associated with conventional drug delivery systems is unpredictable plasma concentrations. The aim of this study was to design a controlled porosity osmotic pump (CPOP) of diltiazem hydrochloride to deliver the drug in a controlled manner. CPOP tablets were prepared by incorporation of drug in the core and subsequent coating with cellulose acetate as semi-permeable membrane. Non-ionic surfactants were applied as pore-formers as well. The effect of pore-formers concentration on the in vitro release of diltiazem was also studied. The formulations were compared based on four comparative parameters, namely, total drug released after 24 h (D24 h), lag-time (tL), squared correlation coefficient of zero order equation (RSQzero) and mean percent deviation from zero order kinetic (MPDzero). Results of scanning electron microscopy studies exhibited formation of pores in the membrane from where the drug release occurred. It was revealed that drug release rate was directly proportional to the concentration of the pore-formers. The value of D24 h in the formulations containing Tween 80 (10%) and Brij 35 (5%) were found to be more than 94.9%, and drug release followed zero order kinetic (RSQzero > 0.99 and MPDzero < 8%) with acceptable tL (lower than 1 h).

[Triton X-100 induces heritable changes of morphological characters in Triticum aestivum L].

PubMed

Makhmudova, K Kh; Bogdanova, E D; Levites, E V

2009-04-01

The effect of the nonionic detergent polyethylene glycol octylphenyl ester (Triton X-100, TX-100) on the spring common wheat cultivar Alem was studied under laboratory and field conditions. Treatment of seeds and vegetating plants with 0.1 or 0.01% TX-100 (aqueous solution) changed the spike morphology in all plants of the first posttreatment generation. The changes were inherited by the second generation without additional treatment with TX-100. Square-headed dense spikes with doubled spikelets of the duospiculum type (an additional spikelet at the top of the main one), elongate dense and lax spikes, mid-dense spikes, and fusiform spikes were observed. An epigenetic nature was assumed for the observed changes.

Enhancement of β-Carotene Synthesis by Citrus Products

PubMed Central

Ciegler, Alex; Nelson, George E. N.; Hall, Harlow H.

1963-01-01

β-Ionone, a stimulatory compound in the microbiological production of β-carotene by mated cultures of Blakeslea trispora, could be replaced with low-cost agricultural by-products (citrus oils, citrus pulp, or citrus molasses) with as good or better carotene yields. Peak yields (81 to 129 mg of carotene per g of dry solids) were achieved in 5 days. The various citrus products tested did not change the pigments produced; all trans-β-carotene remained the pre-dominant pigment. The acid-hydrolyzed soybean meal and corn used in previous production media could be replaced with unhydrolyzed cottonseed embryo meal and corn in a medium that also contained a natural lipid, deodorized kerosene, nonionic detergent, and a precursor. PMID:14021337

In vivo modulation of foreign body response on polyurethane by surface entrapment technique.

PubMed

Khandwekar, Anand P; Patil, Deepak P; Hardikar, Anand A; Shouche, Yogesh S; Doble, Mukesh

2010-11-01

Implanted polymeric materials, such as medical devices, provoke the body to initiate an inflammatory reaction, known as the foreign body response (FBR), which causes several complications. In this study, polyurethane (Tecoflex®, PU) surface modified with the nonionic surfactant Tween80® (PU/T80) and the cell adhesive PLL-RGD peptide (PU/PLL-RGD) by a previously described entrapment technique were implanted in the peritoneal cavity of Wistar rats for 30 days. Implants were retrieved and examined for tissue reactivity and cellular adherence by various microscopic and analytical techniques. Surface-induced inflammatory response was assessed by real-time PCR based quantification of proinflammatory cytokine transcripts, namely, TNF-α and IL-1β, normalized to housekeeping gene GAPDH. Cellular adherence and their distribution profile were assessed by microscopic examination of H&E stained implant sections. It was observed that PU/PLL-RGD followed by the bare PU surface exhibited severe inflammatory and fibrotic response with an average mean thickness of 19 and 12 μm, respectively, in 30 days. In contrast, PU/T80 surface showed only a cellular monolayer of 2-3 μm in thickness, with a mild inflammatory response and no fibrotic encapsulation. The PU/PLL-RGD peptide-modified substrate promoted an enhanced rate of macrophage cell fusion to form foreign body giant cell (FBGCs), whereas FBGCs were rarely observed on Tween80®-modified substrate. The expression levels of proinflammatory cytokines (TNF-α and IL-1β) were upregulated on PU/PLL-RGD surface followed by bare PU, whereas the cytokine expressions were significantly suppressed on PU/T80 surface. Thus, our study highlights modulation of foreign body response on polyurethane surfaces through surface entrapment technique in the form of differential responses observed on PLL-RGD and Tween80® modified surfaces with the former effective in triggering tissue cell adhesion thereby fibrous encapsulation, while the later being mostly resistant to this phenomenon.

Preparation of Salicylic Acid Loaded Nanostructured Lipid Carriers Using Box-Behnken Design: Optimization, Characterization and Physicochemical Stability.

PubMed

Pantub, Ketrawee; Wongtrakul, Paveena; Janwitayanuchit, Wicharn

2017-01-01

Nanostructured lipid carriers loaded salicylic acid (NLCs-SA) were developed and optimized by using the design of experiment (DOE). Box-Behnken experimental design of 3-factor, 3-level was applied for optimization of nanostructured lipid carriers prepared by emulsification method. The independent variables were total lipid concentration (X 1 ), stearic acid to Lexol ® GT-865 ratio (X 2 ) and Tween ® 80 concentration (X 3 ) while the particle size was a dependent variable (Y). Box-Behnken design could create 15 runs by setting response optimizer as minimum particle size. The optimized formulation consists of 10% of total lipid, a mixture of stearic acid and capric/caprylic triglyceride at a 4:1 ratio, and 25% of Tween ® 80 which the formulation was applied in order to prepare in both loaded and unloaded salicylic acid. After preparation for 24 hours, the particle size of loaded and unloaded salicylic acid was 189.62±1.82 nm and 369.00±3.37 nm, respectively. Response surface analysis revealed that the amount of total lipid is a main factor which could affect the particle size of lipid carriers. In addition, the stability studies showed a significant change in particle size by time. Compared to unloaded nanoparticles, the addition of salicylic acid into the particles resulted in physically stable dispersion. After 30 days, sedimentation of unloaded lipid carriers was clearly observed. Absolute values of zeta potential of both systems were in the range of 3 to 18 mV since non-ionic surfactant, Tween ® 80, providing steric barrier was used. Differential thermograms indicated a shift of endothermic peak from 55°C for α-crystal form in freshly prepared samples to 60°C for β´-crystal form in storage samples. It was found that the presence of capric/caprylic triglyceride oil could enhance encapsulation efficiency up to 80% and facilitate stability of the particles.

p27Kip1 localizes to detergent-insoluble microdomains within lymphocyte membranes.

PubMed Central

Yaroslavskiy, B. B.; Stolz, D. B.; Watkins, S. C.; Alber, S. M.; Bradbury, N. A.; Steinman, R. A.

2001-01-01

BACKGROUND: Low levels of the cyclin-dependent kinase inhibitor p27Kip1 are associated with poor prognosis in cancer. It is unclear whether this is related strictly to p27Kip1-mediated cell cycle inhibition or to other, possibly extranuclear, roles of this protein. In this study, we examined p27Kip1 expression in quiescent and activated lymphocytes. T-cell membranes have been shown to possess sphingolipid and cholesterol-rich microdomains that are insoluble in non-ionic detergents. These "rafts" provide a scaffold for signaling proteins. Signal transduction coincides with coalescence of these microdomains into larger complexes. METHODS: Localization of p27Kip1 was studied by electron and confocal microscopy. Association of p27Kip1 with membrane microdomains in unstimulated and stimulated lymphocytes was determined using Western blots analysis of isolated membranes variably treated with detergents. RESULTS: We demonstrated that p27Kip1 was present in clusters associated with the plasma membrane in normal lymphocytes. The solubility profile of p27Kip1 in isolated membranes indicated that it was localized to raft structures. When lymphocytes were stimulated, however, p27Kip1 was excluded from aggregated raft complexes. CONCLUSIONS: This study identifies, for the first time, the localization of p27 within a membrane microdomain associated with signaling. Because some cell surface signaling complexes lose p27Kip1 upon cellular activation, p27Kip1 may play a functional role in modulating membrane signaling. PMID:11474127

The impact of N,N-dimethyldodecylamine N-oxide (DDAO) concentration on the crystallisation of sodium dodecyl sulfate (SDS) systems and the resulting changes to crystal structure, shape and the kinetics of crystal growth.

PubMed

Summerton, Emily; Hollamby, Martin J; Zimbitas, Georgina; Snow, Tim; Smith, Andrew J; Sommertune, Jens; Bettiol, Jeanluc; Jones, Christopher; Britton, Melanie M; Bakalis, Serafim

2018-05-19

At low temperatures stability issues arise in commercial detergent products when surfactant crystallisation occurs, a process which is not currently well-understood. An understanding of the phase transition can be obtained using a simple binary SDS (sodium dodecyl sulfate) + DDAO (N,N-dimethyldodecylamine N-oxide) aqueous system. It expected that the crystallisation temperature of an SDS system can be lowered with addition of DDAO, thus providing a route to improve detergent stability. Detergent systems are typically comprised of anionic surfactants, non-ionic surfactants and water. This study explores the crystallisation of a three component system consisting of sodium dodecyl sulfate (SDS), N,N-dimethyldodecylamine N-oxide (DDAO), and water using wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC) and confocal Raman microscopy. The presence of DDAO lowered the crystallisation temperature of a 20 wt% SDS system. For all aqueous mixtures of SDS + DDAO at low temperatures, SDS hydrated crystals, SDS.1/2H 2 O or SDS·H 2 O, formed. SDS hydrates comprising of layers of SDS separated by water layers. DDAO tended to reside in the vicinity of these SDS crystals. In the absence of DDAO an additional intermediary hydrate structure, SDS.1/8H 2 O, formed whereas for mixed SDS + DDAO systems no such structure was detected during crystallisation. Copyright © 2018. Published by Elsevier Inc.

Effects of surfactants on the microstructure of porous ceramic scaffolds fabricated by foaming for bone tissue engineering

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

Wang Xi, E-mail: nano-sun@hotmail.com; Ruan Jianming; Chen Qiyuan

2009-06-03

A porous scaffold comprising a {beta}-tricalcium phosphate matrix and bioactive glass powders was fabricated by foaming method and the effects of surfactants as foaming agent on microstructure of scaffolds were investigated. Foaming capacity and foam stability of different surfactants in water firstly were carried out to evaluate their foam properties. The porous structure and pore size distribution of the scaffolds were systematically characterized by scanning electron microscopy (SEM) and an optical microscopy connected to an image analyzer. The results showed that the foam stability of surfactant has more remarkable influence on their microstructure such as pore shape, size and interconnectivitymore » than the foaming ability of one. Porous scaffolds fabricated using nonionic surfactant Tween 80 with large foam stability exhibited higher open and total porosities, and fully interconnected porous structure with a pore size of 750-850 {mu}m.« less

Surfactant selection for a liquid foam-bed photobioreactor.

PubMed

Janoska, Agnes; Vázquez, María; Janssen, Marcel; Wijffels, René H; Cuaresma, María; Vílchez, Carlos

2018-02-01

A novel liquid foam-bed photobioreactor has been shown to hold potential as an innovative technology for microalgae production. In this study, a foam stabilizing agent has been selected which fits the requirements of use in a liquid foam-bed photobioreactor. Four criteria were used for an optimal surfactant: the surfactant should have good foaming properties, should not be rapidly biodegradable, should drag up microalgae in the foam formed, and it should not be toxic for microalgae. Ten different surfactants (nonionic, cationic, and anionic) and two microalgae genera (Chlorella and Scenedesmus) were compared on the above-mentioned criteria. The comparison showed the following facts. Firstly, poloxameric surfactants (Pluronic F68 and Pluronic P84) have acceptable foaming properties described by intermediate foam stability and liquid holdup and small bubble size. Secondly, the natural surfactants (BSA and Saponin) and Tween 20 were easily biodegraded by bacteria within 3 days. Thirdly, for all surfactants tested the microalgae concentration is reduced in the foam phase compared to the liquid phase with exception of the cationic surfactant CTAB. Lastly, only BSA, Saponin, Tween 20, and the two Pluronics were not toxic at concentrations of 10 CMC or higher. The findings of this study indicate that the Pluronics (F68 and P84) are the best surfactants regarding the above-mentioned criteria. Since Pluronic F68 performed slightly better, this surfactant is recommended for application in a liquid foam-bed photobioreactor. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

Optimization of the canola oil based vitamin E nanoemulsions stabilized by food grade mixed surfactants using response surface methodology.

PubMed

Mehmood, Tahir

2015-09-15

The objective of the present study was to prepare canola oil based vitamin E nanoemulsions by using food grade mixed surfactants (Tween:80 and lecithin; 3:1) to replace some concentration of nonionic surfactants (Tween 80) with natural surfactant (soya lecithin) and to optimize their preparation conditions. RBD (Refined, Bleached and Deodorized) canola oil and vitamin E acetate were used in water/vitamin E/oil/surfactant system due to their nutritional benefits and oxidative stability, respectively. Response surface methodology (RSM) was used to optimize the preparation conditions. The effects of homogenization pressure (75-155MPa), oil concentrations (4-12% w/w), surfactant concentrations (3-11% w/w) and vitamin E acetate contents (0.4-1.2% w/w) on the particle size and emulsion stability were studied. RSM analysis has shown that the experimental data could be fitted well into second-order polynomial model with the coefficient of determinations of 0.9464 and 0.9278 for particle size and emulsion stability, respectively. The optimum values of independent variables were 135MPa homogenization pressure, 6.18% oil contents, 6.39% surfactant concentration and 1% vitamin E acetate concentration. The optimized response values for particle size and emulsion stability were 150.10nm and 0.338, respectively. Whereas, the experimental values for particle size and nanoemulsion stability were 156.13±2.3nm and 0.328±0.015, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantitative determination of BAF312, a S1P-R modulator, in human urine by LC-MS/MS: prevention and recovery of lost analyte due to container surface adsorption.

PubMed

Li, Wenkui; Luo, Suyi; Smith, Harold T; Tse, Francis L S

2010-02-15

Analyte loss due to non-specific binding, especially container surface adsorption, is not uncommon in the quantitative analysis of urine samples. In developing a sensitive LC-MS/MS method for the determination of a drug candidate, BAF312, in human urine, a simple procedure was outlined for identification, confirmation and prevention of analyte non-specific binding to a container surface and to recover the 'non-specific loss' of an analyte, if no transfer has occurred to the original urine samples. Non-specific binding or container surface adsorption can be quickly identified by using freshly spiked urine calibration standards and pre-pooled QC samples during a LC-MS/MS feasibility run. The resulting low recovery of an analyte in urine samples can be prevented through the use of additives, such as the non-ionic surfactant Tween-80, CHAPS and others, to the container prior to urine sample collection. If the urine samples have not been transferred from the bulk container, the 'non-specific binding' of an analyte to the container surface can be reversed by the addition of a specified amount of CHAPS, Tween-80 or bovine serum albumin, followed by appropriate mixing. Among the above agents, Tween-80 is the most cost-effective. beta-cyclodextrin may be suitable in stabilizing the analyte of interest in urine via pre-treating the matrix with the agent. However, post-addition of beta-cyclodextrin to untreated urine samples does not recover the 'lost' analyte due to non-specific binding or container surface adsorption. In the case of BAF312, a dynamic range of 0.0200-20.0 ng/ml in human urine was validated with an overall accuracy and precision for QC sample results ranging from -3.2 to 5.1% (bias) and 3.9 to 10.2% (CV), respectively. Pre- and post-addition of 0.5% (v/v) Tween-80 to the container provided excellent overall analyte recovery and minimal MS signal suppression when a liquid-liquid extraction in combination with an isocratic LC separation was employed. The compound was stable in 0.5% Tween-80 treated human urine QC samples for at least 24 h at room temperature, after three freeze/thaw cycles with storage at < or =-60 degrees C and for at least 3 months when stored at < or =-60 degrees C. The current work could serve as a simple example in trouble shooting non-specific binding or container surface adsorption in quantitative analysis of urine samples. Copyright 2010. Published by Elsevier B.V.

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.

Cloning, expression, purification and characterization of lipase from Bacillus licheniformis, isolated from hot spring of Himachal Pradesh, India.

PubMed

Kaur, Gagandeep; Singh, Amninder; Sharma, Rohit; Sharma, Vinay; Verma, Swati; Sharma, Pushpender K

2016-06-01

In the present investigation, a gene encoding extracellular lipase was cloned from a Bacillus licheniformis. The recombinant protein containing His-tag was expressed as inclusion bodies in Esherichia coli BL21DE3 cells, using pET-23a as expression vector. Expressed protein purified from the inclusion bodies demonstrated ~22 kDa protein band on 12 % SDS-PAGE. It exhibited specific activity of 0.49 U mg -1 and % yield of 8.58. Interestingly, the lipase displayed activity at wide range of pH and temperature, i.e., 9.0-14.0 pH and 30-80 °C, respectively. It further demonstrated ~100 % enzyme activity in presence of various organic solvents. Enzyme activity was strongly inhibited in the presence of β-ME. Additionally, the serine and histidine modifiers also inhibited the enzyme activities strongly at all concentrations that suggest their role in the catalytic center. Enzyme could retain its activity in presence of various detergents (Triton X-100, Tween 20, Tween 40, SDS). Sequence and structural analysis employing in silico tools revealed that the lipase contained two highly conserved sequences consisting of ITITGCGNDL and NLYNP, arranged as parallel β-sheet in the core of the 3D structure. The function of these conserve sequences have not fully understood.

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.

The membrane-associated form of α(s1)-casein interacts with cholesterol-rich detergent-resistant microdomains.

PubMed

Le Parc, Annabelle; Honvo Houéto, Edith; Pigat, Natascha; Chat, Sophie; Leonil, Joëlle; Chanat, Eric

2014-01-01

Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that α(s1)-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of α(s1)-casein in rat mammary epithelial cells. Using metabolic labelling we show that α(s1)-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of α(s1)-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of α(s1)-casein. These experiments reveal that the insolubility of α(s1)-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of α(s1)-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells.

Optimized Standard Operating Procedures for the Analysis of Cerebrospinal Fluid Aβ42 and the Ratios of Aβ Isoforms Using Low Protein Binding Tubes.

PubMed

Vanderstichele, Hugo Marcel Johan; Janelidze, Shorena; Demeyer, Leentje; Coart, Els; Stoops, Erik; Herbst, Victor; Mauroo, Kimberley; Brix, Britta; Hansson, Oskar

2016-05-31

Reduced cerebrospinal fluid (CSF) concentration of amyloid-β1-42 (Aβ1-42) reflects the presence of amyloidopathy in brains of subjects with Alzheimer's disease (AD). To qualify the use of Aβ1-42/Aβ1-40 for improvement of standard operating procedures (SOP) for measurement of CSF Aβ with a focus on CSF collection, storage, and analysis. Euroimmun ELISAs for CSF Aβ isoforms were used to set up a SOP with respect to recipient properties (low binding, polypropylene), volume of tubes, freeze/thaw cycles, addition of detergents (Triton X-100, Tween-20) in collection or storage tubes or during CSF analysis. Data were analyzed with linear repeated measures and mixed effects models. Optimization of CSF analysis included a pre-wash of recipients (e.g., tubes, 96-well plates) before sample analysis. Using the Aβ1-42/Aβ1-40 ratio, in contrast to Aβ1-42, eliminated effects of tube type, additional freeze/thaw cycles, or effect of CSF volumes for polypropylene storage tubes. 'Low binding' tubes reduced the loss of Aβ when aliquoting CSF or in function of additional freeze/thaw cycles. Addition of detergent in CSF collection tubes resulted in an almost complete absence of variation in function of collection procedures, but affected the concentration of Aβ isoforms in the immunoassay. The ratio of Aβ1-42/Aβ1-40 is a more robust biomarker than Aβ1-42 toward (pre-) analytical interfering factors. Further, 'low binding' recipients and addition of detergent in collection tubes are able to remove effects of SOP-related confounding factors. Integration of the Aβ1-42/Aβ1-40 ratio and 'low-binding tubes' into guidance criteria may speed up worldwide standardization of CSF biomarker analysis.

The Membrane-Associated Form of αs1-Casein Interacts with Cholesterol-Rich Detergent-Resistant Microdomains

PubMed Central

Le Parc, Annabelle; Honvo Houéto, Edith; Pigat, Natascha; Chat, Sophie; Leonil, Joëlle; Chanat, Eric

2014-01-01

Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that αs1-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of αs1-casein in rat mammary epithelial cells. Using metabolic labelling we show that αs1-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of αs1-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of αs1-casein. These experiments reveal that the insolubility of αs1-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of αs1-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells. PMID:25549363

New Binding Mode to TNF-Alpha Revealed by Ubiquitin-Based Artificial Binding Protein

PubMed Central

Hoffmann, Andreas; Kovermann, Michael; Lilie, Hauke; Fiedler, Markus; Balbach, Jochen; Rudolph, Rainer; Pfeifer, Sven

2012-01-01

A variety of approaches have been employed to generate binding proteins from non-antibody scaffolds. Utilizing a beta-sheet of the human ubiquitin for paratope creation we obtained binding proteins against tumor necrosis factor (TNF)-alpha. The bioactive form of this validated pharmacological target protein is a non-covalently linked homo-trimer. This structural feature leads to the observation of a certain heterogeneity concerning the binding mode of TNF-alpha binding molecules, for instance in terms of monomer/trimer specificity. We analyzed a ubiquitin-based TNF-alpha binder, selected by ribosome display, with a particular focus on its mode of interaction. Using enzyme-linked immunosorbent assays, specific binding to TNF-alpha with nanomolar affinity was observed. In isothermal titration calorimetry we obtained comparable results regarding the affinity and detected an exothermic reaction with one ubiquitin-derived binding molecule binding one TNF-alpha trimer. Using NMR spectroscopy and other analytical methods the 1∶3 stoichiometry could be confirmed. Detailed binding analysis showed that the interaction is affected by the detergent Tween-20. Previously, this phenomenon was reported only for one other type of alternative scaffold-derived binding proteins – designed ankyrin repeat proteins – without further investigation. As demonstrated by size exclusion chromatography and NMR spectroscopy, the presence of the detergent increases the association rate significantly. Since the special architecture of TNF-alpha is known to be modulated by detergents, the access to the recognized epitope is indicated to be restricted by conformational transitions within the target protein. Our results suggest that the ubiquitin-derived binding protein targets a new epitope on TNF-alpha, which differs from the epitopes recognized by TNF-alpha neutralizing antibodies. PMID:22363609

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.

Vehicle-dependent disposition kinetics of fluoranthene in Fisher-344 rats.

PubMed

Harris, Deacqunita L; Hood, Darry B; Ramesh, Aramandla

2008-03-01

The objective of this study was to evaluate how the vehicles of choice affect the pharmacokinetics of orally administered Fluoranthene [FLA] in rats. Fluoranthene is a member of the family of Polycyclic Aromatic Hydrocarbon chemicals. Fluoranthene exposure to humans may occur as a result of cigarette smoking, consumption of contaminated food and water, heating woods in stoves and boilers, industrial sources such as coal gasification, carbon and graphite electrode manufacturing. Adult male Fisher-344 rats were given single oral doses of 25 and 50 microg/kg FLA in tricaprylin, peanut oil, cod liver oil, Tween 80/isotonic saline (1:5) and 2% Alkamuls-EL620 through gavage. After administration, the rats were housed individually in metabolic cages and sacrificed at 2, 4, 6, 8, 10 and 12 hours post FLA exposure. Blood, lung, liver, small intestine, adipose tissue samples, urine, and feces were collected at each time point. Samples were subjected to a liquid-liquid extraction using methanol, chloroform, and water. The extracts were analyzed by a reverse-phase HPLC, equipped with a fluorescence detector. The results revealed a dose-dependent increase in FLA concentrations in plasma and tissues for all the vehicles used. Plasma and tissue FLA concentrations were greater for peanut oil; cod liver oil, and tricaprylin vehicles compared to Alkamuls (p < 0.05), and Tween 80/isotonic saline (1:5). Most of the FLA administered through peanut oil, cod liver oil and tricaprylin was cleared from the body by 8 hours (90%) and 12 hours (80%) post administration for the 25 microg/kg and 50 microg/kg dose groups, respectively. With both doses employed, the metabolism of FLA was highest when cod liver oil was used as a vehicle and lowest in vehicles containing detergent/water [cod liver oil > peanut oil > tricaprylin > alkamuls > Tween 80/isotonic saline (1:5)]. These findings suggest that uptake and elimination of FLA is accelerated when administered through oil-based vehicles. The low uptake of FLA from Alkamuls and Tween 80/isotonic saline may have been a result of the poor solubility of the chemical. In summary, our findings reiterate that absorption characteristics of FLA were governed by the dose as well as the dosing vehicle. The vehicle-dependent bioavailability of FLA suggests a need for the judicious selection of vehicles in evaluating oral toxicity studies for risk assessment purposes.

Disaggregation of adenylate cyclase during polyacrylamide-gel electrophoresis in mixtures of ionic and non-ionic detergents.

PubMed

Newby, A C; Chrambach, A

1979-02-01

1. Adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] solubilized from the rat liver plasma membrane with 1% Lubrol PX and partially purified by gel filtration in buffer containing 0.01% Lubrol PX was physically characterized by polyacrylamide-gel electrophoresis. 2. The molecular radius determined for the partially purified enzyme was 4.9nm, compared with the value of 3.9nm obtained for the enzyme before gel filtration. 3. This difference, representing an approximate doubling of the molecular volume of the enzyme, implied that aggregation with itself or other proteins had occurred during partial purification. 4. Aggregation was not reversed by electrophoresis in the presence of high Lubrol concentrations. 5. Substitution of deoxycholate or N-dodecylsarcosinate for Lubrol PX either for solubilization or during electrophoresis led to poorer resolution of membrane proteins at concentrations giving greater than 70% loss of enzyme activity. 6. Partially purified adenylate cyclase was electrophoresed in the presence of mixed micelles of Lubrol PX and deoxycholate or Lubrol PX and N-dodecylsarcosinate. Different mixtures were examined simultaneously in a suitable apparatus. 7. Electrophoresis in the presence of 0.1% Lubrol plus 0.03% deoxycholate decreased the molecular radius of the cyclase to 4.0nm, with greater than 90% recovery of enzymic activity. The net charge of the enzyme was also increased, indicating ionic detergent binding. 8. With 0.1% Lubrol plus 0.03% N-dodecylsarcosinate the molecular radius was 4.3nm, recovery approx. 50% and net charge similar to that seen in Lubrol plus deoxycholate. 9. The resolution of cyclase from bulk protein, on an analytical scale, was improved in the presence of detergent mixtures, as compared with resolution in Lubrol alone. 10. The results demonstrate the usefulness of polyacrylamide-gel electrophoresis to detect and overcome aggregation problems with membrane proteins and suggest that detergent mixtures in specific ratios may be useful in the purification of adenylate cyclase and other intrinsic membrane proteins.

Proteomic Analysis of Detergent Resistant Membrane Domains during Early Interaction of Macrophages with Rough and Smooth Brucella melitensis

PubMed Central

Lauer, Sabine A.; Iyer, Srinivas; Sanchez, Timothy; Forst, Christian V.; Bowden, Brent; Carlson, Kay; Sriranganathan, Nammalwar; Boyle, Stephen M.

2014-01-01

The plasma membrane contains discrete nanometer-sized domains that are resistant to non-ionic detergents, and which are called detergent resistant membrane domains (DRMDs) or lipid rafts. Exposure of host cells to pathogenic bacteria has been shown to induce the re-distribution of specific host proteins between DRMDs and detergent soluble membranes, which leads to the initiation of cell signaling that enable pathogens to access host cells. DRMDs have been shown to play a role in the invasion of Brucella into host macrophages and the formation of replicative phagosomes called Brucella-containing vacuoles (BCVs). In this study we sought to characterize changes to the protein expression profiles in DRMDs and to respective cellular pathways and networks of Mono Mac 6 cells in response to the adherence of rough VTRM1 and smooth 16 M B. melitensis strains. DRMDs were extracted from Mono Mac 6 cells exposed for 2 minutes at 4°C to Brucella (no infection occurs) and from unexposed control cells. Protein expression was determined using the non-gel based quantitative iTRAQ (Isobaric Tags for Relative and Absolute Quantitation) mass spectrometry technique. Using the identified iTRAQ proteins we performed enrichment analyses and probed constructed human biochemical networks for interactions and metabolic reactions. We identified 149 proteins, which either became enriched, depleted or whose amounts did not change in DRMDs upon Brucella exposure. Several of these proteins were distinctly enriched or depleted in DRMDs upon exposure to rough and smooth B. melitensis strains which results in the differential engagement of cellular pathways and networks immediately upon Brucella encounter. For some of the proteins such as myosin 9, small G protein signaling modulator 3, lysine-specific demethylase 5D, erlin-2, and voltage-dependent anion-selective channel protein 2, we observed extreme differential depletion or enrichment in DRMDs. The identified proteins and pathways could provide the basis for novel ways of treating or diagnosing Brucellosis. PMID:24643124

Characterization of a Biomimetic Mesophase Composed of Nonionic Surfactants and an Aqueous Solvent.

PubMed

Adrien, V; Rayan, G; Reffay, M; Porcar, L; Maldonado, A; Ducruix, A; Urbach, W; Taulier, N

2016-10-11

We have investigated the physical and biomimetic properties of a sponge (L 3 ) phase composed of pentaethylene glycol monododecyl ether (C 12 E 5 ), a nonionic surfactant, an aqueous solvent, and a cosurfactant. The following cosurfactants, commonly used for solubilizing membrane proteins, were incorporated: n-octyl-β-d-glucopyranoside (β-OG), n-dodecyl-β-d-maltopyranoside (DDM), 4-cyclohexyl-1-butyl-β-d-maltoside (CYMAL-4), and 5-cyclohexyl-1-pentyl-β-d-maltoside (CYMAL-5). Partial phase diagrams of these systems were created. The L 3 phase was characterized using crossed polarizers, diffusion of a fluorescent probe by fluorescence recovery after pattern photobleaching (FRAPP), and freeze fracture electron microscopy (FFEM). By varying the hydration of the phase, we were able to tune the distance between adjacent bilayers. The characteristic distance (d b ) of the phase was obtained from small angle scattering (SAXS/SANS) as well as from FFEM, which yielded complementary d b values. These d b values were neither affected by the nature of the cosurfactant nor by the addition of membrane proteins. These findings illustrate that a biomimetic surfactant sponge phase can be created in the presence of several common membrane protein-solubilizing detergents, thus making it a versatile medium for membrane protein studies.

Novel characteristics of sophorolipids, yeast glycolipid biosurfactants, as biodegradable low-foaming surfactants.

PubMed

Hirata, Yoshihiko; Ryu, Mizuyuki; Oda, Yuka; Igarashi, Keisuke; Nagatsuka, Asami; Furuta, Taro; Sugiura, Masaki

2009-08-01

Sophorolipids (SLs) are a family of glycolipid type biosurfactants, which are largely produced by the non-pathogenic yeast, Candida bombicola. In order to investigate the possibility of SLs for industrial use, here we examined the interfacial activities, cytotoxicity and biodegradability of SLs, and compared these properties with those of two lipopeptide type biosurfactants (surfactin and arthrofactin), sodium laurate (soap, SP) and four kinds of chemically synthesized surfactants including two block-copolymer nonionic surfactants (BPs), polyoxyethylene lauryl ether (AE) and sodium dodecyl sulfate (SDS). It was indicated that SLs had extremely low-foaming properties and high detergency comparable with commercially available low-foaming BPs. These interfacial activities of SLs were maintained under 100 ppm water hardness. Cytotoxicity of SLs on human keratinocytes was the same as surfactin, which has already been commercialized as cosmetic material, but higher than BPs. Moreover, biodegradability of SLs using the OECD Guidelines for Testing of Chemicals (301C, Modified MITI Test) displayed that SLs can be classified as "readily" biodegradable chemicals, which are defined as chemicals that are degraded 60% within 28 days under specified test methods. We observed 61% degradation of SLs on the eighth day of cultivation. Our results indicate that SLs are low-foaming surfactants with high detergency, which also exhibit both low cytotoxicity and readily biodegradable properties.

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

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.

Biodegradation of complex hydrocarbons in spent engine oil by novel bacterial consortium isolated from deep sea sediment.

PubMed

Ganesh Kumar, A; Vijayakumar, Lakshmi; Joshi, Gajendra; Magesh Peter, D; Dharani, G; Kirubagaran, R

2014-10-01

Complex hydrocarbon and aromatic compounds degrading marine bacterial strains were isolated from deep sea sediment after enrichment on spent engine (SE) oil. Phenotypic characterization and phylogenetic analysis of 16S rRNA gene sequences showed the isolates were related to members of the Pseudoalteromonas sp., Ruegeria sp., Exiguobacterium sp. and Acinetobacter sp. Biodegradation using 1% (v/v) SE oil with individual and mixed strains showed the efficacy of SE oil utilization within a short retention time. The addition of non-ionic surfactant 0.05% (v/v) Tween 80 as emulsifying agent enhanced the solubility of hydrocarbons and renders them more accessible for biodegradation. The degradation of several compounds and the metabolites formed during the microbial oxidation process were confirmed by Fourier transform infrared spectroscopy and Gas chromatography-mass spectrometry analyses. The potential of this consortium to biodegrade SE oil with and without emulsifying agent provides possible application in bioremediation of oil contaminated marine environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Study on the sorption behaviour of estrone on marine sediments.

PubMed

Zhang, Jing; Yang, Gui-Peng; Li, Quan; Cao, Xiaoyan; Liu, Guangxing

2013-11-15

The sorption behaviour of estrone (E1) on marine sediments treated by different methods was systematically investigated. About 22 h was required for sorption equilibrium of E1. Sorption isotherms of E1 were well fitted with Freundlich model. The sorption behaviour of E1 on HCl-treatment and H2O-treatment sediments related significantly with the sediment organic carbon contents. Additionally, clay minerals and surface areas of sediments played dominant roles in the sorption of E1 on H2O2-treatment sediments. Some external factors which could affect sorption behaviour of E1 were also investigated. Our results showed that the sorption capacity of E1 on the sediments increased with the increasing concentrations of cationic surfactant cetyltrimethylammonium bromide (CTAB), nonionic surfactant polyoxyethylene (80) sorbitan esters (Tween 80) and salinity of seawater. In contrast, the sorption capacity of E1 decreased with the increasing concentration of anionic surfactant sodium dodecylbenzene sulfonate (SDBS), pH value and temperature of seawater. Copyright © 2013 Elsevier Ltd. All rights reserved.

Niosomes encapsulating Ibuprofen-cyclodextrin complexes: preparation and characterization.

PubMed

Marianecci, Carlotta; Rinaldi, Federica; Esposito, Sara; Di Marzio, Luisa; Carafa, Maria

2013-08-01

A new delivery system based on ibuprofen-β-cyclodextrin (βCd) complexation and its loading into non-ionic surfactant vesicles (NSVs) was developed to improve ibuprofen therapeutic efficacy in topical formulations. The proposed strategy exploits the well known solubilizing and stabilizing properties of cyclodextrins together with the high tolerability and percutaneous absorption enhancing properties of NSVs. The complexing capacity of Cds in the presence of Ibuprofen in aqueous solution was evaluated by means of phase solubility studies. The technique used to obtain solid ibuprofen-βCd complexes was the co-lyophilization method. The influence of the preparation method on the physicochemical properties of the final product was evaluated by means of Fourier Transform Infrared Spectroscopy and Differential scanning calorimetry studies. Ibuprofen-βCd complexes were included in Tween 20/Cholesterol vesicles and characterized in terms of size, zeta (ζ)-potential, stability, drug entrapment efficiency and drug release. The best ibuprofen-βCd-NSV system exhibited in vitro drug permeation properties significantly improved with respect to those of the plain drug suspension.

Association of gamma-secretase with lipid rafts in post-Golgi and endosome membranes.

PubMed

Vetrivel, Kulandaivelu S; Cheng, Haipeng; Lin, William; Sakurai, Takashi; Li, Tong; Nukina, Nobuyuki; Wong, Philip C; Xu, Huaxi; Thinakaran, Gopal

2004-10-22

Alzheimer's disease-associated beta-amyloid peptides (Abeta) are generated by the sequential proteolytic processing of amyloid precursor protein (APP) by beta- and gamma-secretases. There is growing evidence that cholesterol- and sphingolipid-rich membrane microdomains are involved in regulating trafficking and processing of APP. BACE1, the major beta-secretase in neurons is a palmitoylated transmembrane protein that resides in lipid rafts. A subset of APP is subject to amyloidogenic processing by BACE1 in lipid rafts, and this process depends on the integrity of lipid rafts. Here we describe the association of all four components of the gamma-secretase complex, namely presenilin 1 (PS1)-derived fragments, mature nicastrin, APH-1, and PEN-2, with cholesterol-rich detergent insoluble membrane (DIM) domains of non-neuronal cells and neurons that fulfill the criteria of lipid rafts. In PS1(-/-)/PS2(-/-) and NCT(-/-) fibroblasts, gamma-secretase components that still remain fail to become detergent-resistant, suggesting that raft association requires gamma-secretase complex assembly. Biochemical evidence shows that subunits of the gamma-secretase complex and three TGN/endosome-resident SNAREs cofractionate in sucrose density gradients, and show similar solubility or insolubility characteristics in distinct non-ionic and zwitterionic detergents, indicative of their co-residence in membrane microdomains with similar protein-lipid composition. This notion is confirmed using magnetic immunoisolation of PS1- or syntaxin 6-positive membrane patches from a mixture of membranes with similar buoyant densities following Lubrol WX extraction or sonication, and gradient centrifugation. These findings are consistent with the localization of gamma-secretase in lipid raft microdomains of post-Golgi and endosomes, organelles previously implicated in amyloidogenic processing of APP.

Association of γ-Secretase with Lipid Rafts in Post-Golgi and Endosome Membranes*

PubMed Central

Vetrivel, Kulandaivelu S.; Cheng, Haipeng; Lin, William; Sakurai, Takashi; Li, Tong; Nukina, Nobuyuki; Wong, Philip C.; Xu, Huaxi; Thinakaran, Gopal

2005-01-01

Alzheimer’s disease-associated β-amyloid peptides (Aβ) are generated by the sequential proteolytic processing of amyloid precursor protein (APP) by β- and γ-secretases. There is growing evidence that cholesterol- and sphingolipid-rich membrane microdomains are involved in regulating trafficking and processing of APP. BACE1, the major γ-secretase in neurons is a palmi-toylated transmembrane protein that resides in lipid rafts. A subset of APP is subject to amyloidogenic processing by BACE1 in lipid rafts, and this process depends on the integrity of lipid rafts. Here we describe the association of all four components of the γ-secretase complex, namely presenilin 1 (PS1)-derived fragments, mature nicastrin, APH-1, and PEN-2, with cholesterol-rich detergent insoluble membrane (DIM) domains of non-neuronal cells and neurons that fulfill the criteria of lipid rafts. In PS1−/−/PS2−/− and NCT−/− fibroblasts, γ-secretase components that still remain fail to become detergent-resistant, suggesting that raft association requires γ-secretase complex assembly. Biochemical evidence shows that subunits of the γ-secretase complex and three TGN/endosome-resident SNAREs cofractionate in sucrose density gradients, and show similar solubility or insolubility characteristics in distinct non-ionic and zwitterionic detergents, indicative of their co-residence in membrane microdomains with similar protein-lipid composition. This notion is confirmed using magnetic immunoisolation of PS1- or syntaxin 6-positive membrane patches from a mixture of membranes with similar buoyant densities following Lubrol WX extraction or sonication, and gradient centrifugation. These findings are consistent with the localization of γ-secretase in lipid raft microdomains of post-Golgi and endosomes, organelles previously implicated in amyloidogenic processing of APP. PMID:15322084

AUTORADIOGRAPHIC ANALYSIS ON AGAR PLATES OF ANTIGENS FROM SUB CELLULAR FRACTIONS OF RAT LIVER SLICES

PubMed Central

Morgan, W. S.; Perlmann, P.; Hultin, T.

1961-01-01

Slices of rat livers were incubated with 14C amino acids, homogenized, and subjected to differential centrifugation. The microsomes were further extracted with the non-ionic detergent Lubrol W and with EDTA. These extracts and the microsome free "cell sap," freed from the pH 5 precipitable fraction, were subsequently reacted with antisera using agar diffusion techniques. The antisera employed were obtained from rabbits injected with different subcellular fractions of rat liver or with rat serum proteins. When the agar diffusion plates were autoradiographed it was found that some of the precipitates were radioactive while others were not. Control experiments indicated that this labeling was due to the specific incorporation of 14C amino acids into various rat liver antigens during incubation of the slices rather than to a non-specific adsorption of radioactive material to the immunological precipitates. When the slices were incubated with the isotope for up to 30 minutes, the serum proteins which could be extracted from the microsomes with the detergent were strongly labeled, as were a number of additional microsomal antigens of unknown significance. In contrast, the serum proteins present in the cell sap were only weakly labeled. Most of the typical cell sap proteins, both those precipitable and those soluble at pH 5, seemed to remain unlabeled. No consistently reproducible results were obtained with the EDTA extracts of the ribosomal residues remaining after extraction of the microsomes with the detergent. Incubation of the liver slices for longer periods (up to 120 minutes) led to a strong labeling of the serum proteins in the cell sap as well as to the appearance of labeling in additional cell sap proteins. The results are discussed with regard to the subcellular site of synthesis and the metabolism of the different antigens. PMID:13772607

Rapid and sensitive sandwich enzyme-linked immunosorbent assay for detection of staphylococcal enterotoxin B in cheese.

PubMed Central

Morissette, C; Goulet, J; Lamoureux, G

1991-01-01

A rapid and sensitive screening sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection of staphylococcal enterotoxin B (SEB) in cheese by using a highly avid anti-SEB antibody (Ab) as the capture Ab (CAb) and as the biotinylated Ab conjugate. The glutaraldehyde fixation method for the immobilization of CAb on polystyrene dipsticks was superior to the adsorption fixation and the adsorption-glutaraldehyde fixation methods. The glutaraldehyde fixation method resulted in a higher surface-saturating CAb concentration as evaluated by the peroxidase saturation technique and by the ability of the CAb-coated dipstick to discriminate between positive and negative controls (index of discrimination). Of nine blocking agents used alone or in pairs, lysine-human serum albumin, bovine serum albumin, human serum albumin, and gelatin effectively saturated available sites on the CAb-coated dipsticks without causing interference with the antigen-Ab reactions. The addition of 1% polyethylene glycol to the diluent of the biotinylated anti-SEB Ab conjugate improved the detection of SEB. A concentration of 4% polyethylene glycol allowed a 5-min reaction time for the streptavidin-biotin-horseradish peroxidase conjugate. Cheddar cheese homogenate reduced the sensitivity of the SEB assay; however, the sensitivity was restored when 1.6% (wt/vol) of either a nonionic detergent (Mega-9) or two zwitterionic detergents (Zwittergent 3-10 and 3-12 detergent) was added to the diluent. By using the rapid sandwich ELISA, a minimum of 0.5 to 1.0 ng of SEB per ml was detected within 45 min. The whole procedure for the analysis of the cheddar cheese samples was completed within 1 h.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2039234

Benefits from Tween during enzymic hydrolysis of corn stover

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

Kaar, W.E.; Holtzapple, M.T.

1998-08-20

Corn stover is a potential substrate for fermentation processes. Previous work with corn stover demonstrated that lime pretreatment rendered it digestible by cellulase; however, high sugar yields required very high enzyme loadings. Because cellulase is a significant cost in biomass conversion processes, the present study focused on improving the enzyme efficiency using Tween 20 and Tween 80; Tween 20 is slightly more effective than Tween 80. The recommended pretreatment conditions for the biomass remained unchanged regardless of whether Tween was added during the hydrolysis. The recommended Tween loading was 0.15 g Tween/g dry biomass. The critical relationship was the Tweenmore » loading on the biomass, not the Tween concentration in solution. The 72-h enzymic conversion of pretreated corn stover using 5 FPU cellulase/g dry biomass at 50 C with Tween 20 as part of the medium was 0.85 g/g for cellulose, 0.66 g/g for xylan, and 0.75 for total polysaccharide; addition of Tween improved the cellulose, xylan, and total polysaccharide conversions by 42, 40, and 42%, respectively. Kinetic analyses showed that Tween improved the enzymic absorption constants, which increased the effective hydrolysis rate compared to hydrolysis without Tween. Furthermore, Tween prevented thermal deactivation of the enzymes, which allows for the kinetic advantage of higher temperature hydrolysis. Ultimate digestion studies showed higher conversions for samples containing Tween, indicating a substrate effect. It appears that Tween improves corn stover hydrolysis through three effects: enzyme stabilizer, lignocellulose disrupter, and enzyme effector.« less

A new method of preparing embeddment-free sections for transmission electron microscopy: applications to the cytoskeletal framework and other three-dimensional networks.

PubMed

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

1984-05-01

Diethylene glycol distearate is used as a removable embedding medium to produce embeddment -free sections for transmission electron microscopy. The easily cut sections of this material float and form ribbons in a water-filled knife trough and exhibit interference colors that aid in the selection of sections of equal thickness. The images obtained with embeddment -free sections are compared with those from the more conventional epoxy-embedded sections, and illustrate that embedding medium can obscure important biological structures, especially protein filament networks. The embeddment -free section methodology is well suited for morphological studies of cytoskeletal preparations obtained by extraction of cells with nonionic detergent in cytoskeletal stabilizing medium. The embeddment -free section also serves to bridge the very different images afforded by embedded sections and unembedded whole mounts.

Trace analysis of surfactants in Corexit oil dispersant formulations and seawater

NASA Astrophysics Data System (ADS)

Place, Benjamin J.; Perkins, Matt J.; Sinclair, Ewan; Barsamian, Adam L.; Blakemore, Paul R.; Field, Jennifer A.

2016-07-01

After the April 2010 explosion on the Deepwater Horizon oil rig, and subsequent release of millions of barrels of oil, two Corexit oil dispersant formulations were used in unprecedented quantities both on the surface and sub-surface of the Gulf of Mexico. Although the dispersant formulations contain four classes of surfactants, current studies to date focus on the anionic surfactant, bis-(2-ethylhexyl) sulfosuccinate (DOSS). Factors affecting the integrity of environmental and laboratory samples for Corexit analysis have not been systematically investigated. For this reason, a quantitative analytical method was developed for the detection of all four classes of surfactants, as well as the hydrolysis products of DOSS, the enantiomeric mixture of α- and β-ethylhexyl sulfosuccinate (α-/β-EHSS). The analytical method was then used to evaluate which practices for sample collection, storage, and analysis resulted in high quality data. Large volume, direct injection of seawater followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) minimized analytical artifacts, analysis time, and both chemical and solid waste. Concentrations of DOSS in the seawater samples ranged from 71 to 13,000 ng/L, while the nonionic surfactants including Span 80, Tween 80, Tween 85 were detected infrequently (26% of samples) at concentrations from 840 to 9100 ng/L. The enantiomers α-/β-EHSS were detected in seawater, at concentrations from 200 to 1900 ng/L, and in both Corexit dispersant formulations, indicating α-/β-EHSS were applied to the oil spill and may be not unambiguous indicator of DOSS degradation. Best practices are provided to ensure sample integrity and data quality for environmental monitoring studies and laboratory that require the detection and quantification of Corexit-based surfactants in seawater.

A new formula for a mild body cleanser: sodium laureth sulphate supplemented with sodium laureth carboxylate and lauryl glucoside.

PubMed

Takagi, Y; Shimizu, M; Morokuma, Y; Miyaki, M; Kiba, A; Matsuo, K; Isoda, K; Mizutani, H

2014-08-01

Sodium laureth sulphate (SLES) is an anionic detergent, which has been used globally for personal care products because of its mildness and good foaming ability. However, SLES is somewhat invasive and stimulatory to the skin, and many consumers with sensitive skin desire milder detergents for daily use skin cleansers. We enhanced the mildness of SLES by formulating it with sodium laureth carboxylate (AEC) and lauryl glucoside (LG). In skin soak tests, 5% detergent solutions were applied to the forearms of 10 Japanese healthy volunteers for 30 min followed by washing with tap water once a day for 4 days. Twenty-four hours after the last treatment, cutaneous capacitance measurements and visual analyses were performed. In a controlled usage study, 16 Japanese healthy volunteers used the test body cleanser for 4 weeks. Assessment of efficacy and mildness was conducted prior to the start of the study and at the end of week 4 by cutaneous conductance, dermoscopic evaluation of the stratum corneum and visual assessment by a dermatologist. In soak tests, cutaneous capacitance was significantly decreased on the soap-treated region and on the SLES-treated region. No significant decrease was identified on the SLES/AEC/LG-treated region with less induction of erythema or dryness. In the controlled usage study, no significant changes in cutaneous conductance or texture or damage of corneocytes on the forearm and lower thigh were found. However, visual assessment revealed a significant decrease in scaling and erythema on the lower thigh after 4 weeks of usage with an improvement of the discomfort of the consumer. The favourability rating of this formulated detergent in several questionnaire items was very good. The newly formulated skin cleanser with the combination of anionic surfactants SLES and AEC and the non-ionic surfactant LG provides a mild surfactant with a satisfactory cleansing activity for body washing. © 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Disaggregation of adenylate cyclase during polyacrylamide-gel electrophoresis in mixtures of ionic and non-ionic detergents

PubMed Central

Newby, Andrew C.; Chrambach, Andreas

1979-01-01

1. Adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] solubilized from the rat liver plasma membrane with 1% Lubrol PX and partially purified by gel filtration in buffer containing 0.01% Lubrol PX was physically characterized by polyacrylamide-gel electrophoresis. 2. The molecular radius determined for the partially purified enzyme was 4.9nm, compared with the value of 3.9nm obtained for the enzyme before gel filtration. 3. This difference, representing an approximate doubling of the molecular volume of the enzyme, implied that aggregation with itself or other proteins had occurred during partial purification. 4. Aggregation was not reversed by electrophoresis in the presence of high Lubrol concentrations. 5. Substitution of deoxycholate or N-dodecylsarcosinate for Lubrol PX either for solubilization or during electrophoresis led to poorer resolution of membrane proteins at concentrations giving greater than 70% loss of enzyme activity. 6. Partially purified adenylate cyclase was electrophoresed in the presence of mixed micelles of Lubrol PX and deoxycholate or Lubrol PX and N-dodecylsarcosinate. Different mixtures were examined simultaneously in a suitable apparatus. 7. Electrophoresis in the presence of 0.1% Lubrol plus 0.03% deoxycholate decreased the molecular radius of the cyclase to 4.0nm, with greater than 90% recovery of enzymic activity. The net charge of the enzyme was also increased, indicating ionic detergent binding. 8. With 0.1% Lubrol plus 0.03% N-dodecylsarcosinate the molecular radius was 4.3nm, recovery approx. 50% and net charge similar to that seen in Lubrol plus deoxycholate. 9. The resolution of cyclase from bulk protein, on an analytical scale, was improved in the presence of detergent mixtures, as compared with resolution in Lubrol alone. 10. The results demonstrate the usefulness of polyacrylamide-gel electrophoresis to detect and overcome aggregation problems with membrane proteins and suggest that detergent mixtures in specific ratios may be useful in the purification of adenylate cyclase and other intrinsic membrane proteins. ImagesFig. 3. PMID:435255

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

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.

Application of an In Vivo Hepatic Triacylglycerol Production Method in the Setting of a High-Fat Diet in Mice

PubMed Central

Ono-Moore, Kikumi D.; Ferguson, Matthew; Blackburn, Michael L.; Issafras, Hassan; Adams, Sean H.

2016-01-01

High-fat (HF) diets typically promote diet-induced obesity (DIO) and metabolic dysfunction (i.e., insulin resistance, hypertriglyceridemia, and hepatic steatosis). Dysfunction of triacylglycerol (TAG) metabolism may contribute to the development of hepatic steatosis, via increased de novo lipogenesis or repackaging of circulating nonesterified fatty acids (NEFAs). Hepatic TAG production (HTP) rate can be assessed through injecting mice with nonionic detergents that inhibit tissue lipoprotein lipase. Potential confounding effects of detergent-based HTP tests (HTPTs) used in longitudinal studies—including the impact on food intake, energy balance, and weight gain—have not been reported. To examine this, male C57BL/6J mice were fed a 10% or 60% kcal diet. After 4 weeks, the mice underwent an HTPT via poloxamer 407 intraperitoneal injections (1000 mg/kg). Weight gain, energy intake, and postabsorptive TAG levels normalized 7–10 days post-HTPT. The post-HTPT recovery of body weight and energy intake suggest that, in metabolic phenotyping studies, any additional sample collection should occur at least 7–10 days after the HTPT to reduce confounding effects. Diet-specific effects on HTP were also observed: HF-fed mice had reduced HTP, plasma TAG, and NEFA levels compared to controls. In conclusion, the current study highlights the procedural and physiological complexities associated with studying lipid metabolism using a HTPT in the DIO mouse model. PMID:28036028

The oxidation of exogenous and endogenous cytochromeC in mitochondria. A biochemical and ultrastructural study.

PubMed

Muscatello, U; Carafoli, E

1969-03-01

The effect of the nonionic detergent Lubrol on the oxidation of endogenous and exogenous cytochrome c by cytochrome oxidase in intact and fragmented mitochondria was studied. Mitochondria and mitochondrial fragments from liver, kidney, heart, and skeletal muscle have been used. Negatively stained preparations of intact mitochondria showed the particles of Fernández-Morán on the matrix side of their inner membrane system: under these conditions, the oxidation rate of externally added cytochrome c was very high, and it was stimulated very poorly by Lubrol. Mechanical fragmentation of liver mitochondria yielded vesicles with a smooth external profile: also under these conditions, the oxidation of externally added cytochrome c was very high, and poorly stimulated by Lubrol. The oxidation of endogenous cytochrome c was also unaffected by Lubrol. On the other hand, fragmentation of heart and skeletal muscle mitochondria yielded vesicles having numerous particles of Fernández-Morán on their external profiles. Under these conditions, the oxidation of exogenous cytochrome c was low and was markedly stimulated by Lubrol. On the contrary, no activation of the oxidation of endogenous cytochrome c was induced by the detergent. The results indicate a difference in the permeability properties of the two faces of the inner mitochondrial membrane: a permeability barrier for cytochrome c is suggested to exist at the inner face.

THE OXIDATION OF EXOGENOUS AND ENDOGENOUS CYTOCHROME C IN MITOCHONDRIA

PubMed Central

Muscatello, Umberto; Carafoli, Ernesto

1969-01-01

The effect of the nonionic detergent Lubrol on the oxidation of endogenous and exogenous cytochrome c by cytochrome oxidase in intact and fragmented mitochondria was studied. Mitochondria and mitochondrial fragments from liver, kidney, heart, and skeletal muscle have been used. Negatively stained preparations of intact mitochondria showed the particles of Fernández-Morán on the matrix side of their inner membrane system: under these conditions, the oxidation rate of externally added cytochrome c was very high, and it was stimulated very poorly by Lubrol. Mechanical fragmentation of liver mitochondria yielded vesicles with a smooth external profile: also under these conditions, the oxidation of externally added cytochrome c was very high, and poorly stimulated by Lubrol. The oxidation of endogenous cytochrome c was also unaffected by Lubrol. On the other hand, fragmentation of heart and skeletal muscle mitochondria yielded vesicles having numerous particles of Fernández-Morán on their external profiles. Under these conditions, the oxidation of exogenous cytochrome c was low and was markedly stimulated by Lubrol. On the contrary, no activation of the oxidation of endogenous cytochrome c was induced by the detergent. The results indicate a difference in the permeability properties of the two faces of the inner mitochondrial membrane: a permeability barrier for cytochrome c is suggested to exist at the inner face. PMID:4303915

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.

Optimization, purification and characterization of novel thermostable, haloalkaline, solvent stable protease from Bacillus halodurans CAS6 using marine shellfish wastes: a potential additive for detergent and antioxidant synthesis.

PubMed

Annamalai, Neelamegam; Rajeswari, Mayavan Veeramuthu; Thavasi, Rengathavasi; Vijayalakshmi, Shanmugam; Balasubramanian, Thangavel

2013-07-01

A protease producing marine bacterium, Bacillus halodurans CAS6 isolated from marine sediments, was found to produce higher enzyme by utilizing shrimp shell powder. Optimum culture conditions for protease production were 50 °C, pH 9.0, 30 % NaCl and 1 % shrimp shell powder (SSP) and the protease purified with a specific activity of 509.84 U/mg. The enzyme retained 100 % of its original activity even at 70 °C, pH 10.0 and 30 % NaCl for 1 h. The purified protease exhibited higher stability when treated with ionic, non-ionic (72-94 %) and commercial detergents (76-88 %), and organic solvents (88-126 %). Significant blood stain removal activity was found with the enzyme in washing experiments. The culture supernatant supplemented with 1 % SSP showed 93.67 ± 2.52 % scavenging activity and FT-IR analysis of the reaction mixture confirmed the presence of antioxidants such as cyclohexane and cyclic depsipeptide with aliphatic amino groups. These remarkable qualities found with this enzyme produced by Bacillus halodurans CAS6 could make this as an ideal candidate to develop the industrial process for bioconversion of marine wastes and antioxidant synthesis.

Application of an In Vivo Hepatic Triacylglycerol Production Method in the Setting of a High-Fat Diet in Mice.

PubMed

Ono-Moore, Kikumi D; Ferguson, Matthew; Blackburn, Michael L; Issafras, Hassan; Adams, Sean H

2016-12-28

High-fat (HF) diets typically promote diet-induced obesity (DIO) and metabolic dysfunction (i.e., insulin resistance, hypertriglyceridemia, and hepatic steatosis). Dysfunction of triacylglycerol (TAG) metabolism may contribute to the development of hepatic steatosis, via increased de novo lipogenesis or repackaging of circulating nonesterified fatty acids (NEFAs). Hepatic TAG production (HTP) rate can be assessed through injecting mice with nonionic detergents that inhibit tissue lipoprotein lipase. Potential confounding effects of detergent-based HTP tests (HTPTs) used in longitudinal studies-including the impact on food intake, energy balance, and weight gain-have not been reported. To examine this, male C57BL/6J mice were fed a 10% or 60% kcal diet. After 4 weeks, the mice underwent an HTPT via poloxamer 407 intraperitoneal injections (1000 mg/kg). Weight gain, energy intake, and postabsorptive TAG levels normalized 7-10 days post-HTPT. The post-HTPT recovery of body weight and energy intake suggest that, in metabolic phenotyping studies, any additional sample collection should occur at least 7-10 days after the HTPT to reduce confounding effects. Diet-specific effects on HTP were also observed: HF-fed mice had reduced HTP, plasma TAG, and NEFA levels compared to controls. In conclusion, the current study highlights the procedural and physiological complexities associated with studying lipid metabolism using a HTPT in the DIO mouse model.

Effective Surfactants Blend Concentration Determination for O/W Emulsion Stabilization by Two Nonionic Surfactants by Simple Linear Regression.

PubMed

Hassan, A K

2015-01-01

In this work, O/W emulsion sets were prepared by using different concentrations of two nonionic surfactants. The two surfactants, tween 80(HLB=15.0) and span 80(HLB=4.3) were used in a fixed proportions equal to 0.55:0.45 respectively. HLB value of the surfactants blends were fixed at 10.185. The surfactants blend concentration is starting from 3% up to 19%. For each O/W emulsion set the conductivity was measured at room temperature (25±2°), 40, 50, 60, 70 and 80°. Applying the simple linear regression least squares method statistical analysis to the temperature-conductivity obtained data determines the effective surfactants blend concentration required for preparing the most stable O/W emulsion. These results were confirmed by applying the physical stability centrifugation testing and the phase inversion temperature range measurements. The results indicated that, the relation which represents the most stable O/W emulsion has the strongest direct linear relationship between temperature and conductivity. This relationship is linear up to 80°. This work proves that, the most stable O/W emulsion is determined via the determination of the maximum R² value by applying of the simple linear regression least squares method to the temperature-conductivity obtained data up to 80°, in addition to, the true maximum slope is represented by the equation which has the maximum R² value. Because the conditions would be changed in a more complex formulation, the method of the determination of the effective surfactants blend concentration was verified by applying it for more complex formulations of 2% O/W miconazole nitrate cream and the results indicate its reproducibility.

Role of dissolved organic carbon upon re-entrainment and surface properties of aquifer bacteria and bacteria-sized microspheres during subsurface transport (Invited)

NASA Astrophysics Data System (ADS)

Harvey, R. W.; Metge, D. W.; Mohanram, A.; Gao, X.; Chorover, J.

2010-12-01

Susceptibilities for in-situ re-entrainment of attached 0.2 and 1.0 μm (diameter) microspheres and groundwater bacteria (Pseudomonas stuzeri and uncultured, native bacteria) were assessed during transport studies involving an organically contaminated, sandy aquifer in Cape Cod, MA. Aquifer sediments between pairs of injection and sampling wells were initially loaded with fluorescently labeled, carboxylated microspheres and bacteria that had been stained with the DNA-specific fluorochrome 4',6-diamidino-2-phenylindole. In response to subsequent hydrodynamic perturbations and injections of deionized water (ionic strength reduction), anionic surfactants (77 μM linear alkylbenzene sulfonates, LAS) and non-ionic surfactant (76 μM polyoxyethylene sorbitan monooleate, Tween 80), differing patterns of re-entrainment were evident for the two colloids. Injections of anionic surfactant and deionized water were the most efficient in causing detachment of the highly hydrophilic and negatively charged microspheres, but largely ineffective in causing re-entrainment of bacteria. In contrast, the nonionic surfactant was highly effective in re-entraining bacteria, but not microspheres. The hydrophobicities and zeta potentials of the indigenous bacteria were highly sensitive to modest concentration changes (0.6 to 1.3 mg L-1) in groundwater dissolved organic carbon (DOC), whereas the microspheres were largely unaffected. The most hydrophilic and negatively charged bacterial community was isolated from groundwater having the lowest DOC. FTIR spectra indicated that the community from the lowest DOC groundwater also had the highest average density of surface carboxyl groups. This indicates that DOC may have a biological effect on native bacteria resulting in changes to surface structures or changes in the makeup of the bacterial community.

Adjustment of trendy, gaming and less assimilated tweens in the United States

PubMed Central

Comulada, W. Scott; Rotheram-Borus, Mary Jane; Carey, George; Poris, Michelle; Lord, Lynwood R.; Mayfield Arnold, Elizabeth

2014-01-01

Youth transitioning from childhood to adolescence (tweens) are exposed to increasing amounts of media and advertisement. Tweens have also emerged as a major marketing segment for corporate America with increasing buying power.We examine how tweens relate to popular culture messages and the association of different orientations to popular culture on adjustment. A secondary data analysis was conducted on a marketing survey of 3527 tweens, aged 10–14 years, obtained from 49 schools using stratified sampling methods. A sample of children nationwide described their preferences on popular culture and measures of psychosocial adjustment. Using cluster analysis, we identified three main clusters or adaptation styles of tweens: (1) those who enjoyed gaming, (2) trendy youth and (3) youth less assimilated into popular culture. There were differences in clusters based on adjustment indices. Gaming and trendy tweens reported higher self-perceptions of being smart, caring and confident compared to less assimilated tweens. However, gaming and trendy tweens worried more about fitting in than less assimilated tweens. Gaming and trendy tweens also endorsed future goals and traditional values more strongly than less assimilated tweens. Trendy tweens reported the strongest positive feelings about substance use. Results suggest that for each method of adaptation (gamer, trendy and less assimilated), there are unique differences in adjustment that can impact the child’s future. Parents and service providers must recognize the complexity of these decisions and be sensitive to the unique needs of youth as they move from childhood to adolescence. PMID:25580153

Adjustment of trendy, gaming and less assimilated tweens in the United States.

PubMed

Comulada, W Scott; Rotheram-Borus, Mary Jane; Carey, George; Poris, Michelle; Lord, Lynwood R; Mayfield Arnold, Elizabeth

2011-09-01

Youth transitioning from childhood to adolescence (tweens) are exposed to increasing amounts of media and advertisement. Tweens have also emerged as a major marketing segment for corporate America with increasing buying power.We examine how tweens relate to popular culture messages and the association of different orientations to popular culture on adjustment. A secondary data analysis was conducted on a marketing survey of 3527 tweens, aged 10-14 years, obtained from 49 schools using stratified sampling methods. A sample of children nationwide described their preferences on popular culture and measures of psychosocial adjustment. Using cluster analysis, we identified three main clusters or adaptation styles of tweens: (1) those who enjoyed gaming, (2) trendy youth and (3) youth less assimilated into popular culture. There were differences in clusters based on adjustment indices. Gaming and trendy tweens reported higher self-perceptions of being smart, caring and confident compared to less assimilated tweens. However, gaming and trendy tweens worried more about fitting in than less assimilated tweens. Gaming and trendy tweens also endorsed future goals and traditional values more strongly than less assimilated tweens. Trendy tweens reported the strongest positive feelings about substance use. Results suggest that for each method of adaptation (gamer, trendy and less assimilated), there are unique differences in adjustment that can impact the child's future. Parents and service providers must recognize the complexity of these decisions and be sensitive to the unique needs of youth as they move from childhood to adolescence.

A new method of preparing embeddment-free sections for transmission electron microscopy: applications to the cytoskeletal framework and other three-dimensional networks

PubMed Central

1984-01-01

Diethylene glycol distearate is used as a removable embedding medium to produce embeddment -free sections for transmission electron microscopy. The easily cut sections of this material float and form ribbons in a water-filled knife trough and exhibit interference colors that aid in the selection of sections of equal thickness. The images obtained with embeddment -free sections are compared with those from the more conventional epoxy-embedded sections, and illustrate that embedding medium can obscure important biological structures, especially protein filament networks. The embeddment -free section methodology is well suited for morphological studies of cytoskeletal preparations obtained by extraction of cells with nonionic detergent in cytoskeletal stabilizing medium. The embeddment -free section also serves to bridge the very different images afforded by embedded sections and unembedded whole mounts. PMID:6539336

Simplified Enrichment of Plasma Membrane Proteins from Arabidopsis thaliana Seedlings Using Differential Centrifugation and Brij-58 Treatment.

PubMed

Collins, Carina A; Leslie, Michelle E; Peck, Scott C; Heese, Antje

2017-01-01

The plasma membrane (PM) forms a barrier between a plant cell and its environment. Proteins at this subcellular location play diverse and complex roles, including perception of extracellular signals to coordinate cellular changes. Analyses of PM proteins, however, are often limited by the relatively low abundance of these proteins in the total cellular protein pool. Techniques traditionally used for enrichment of PM proteins are time consuming, tedious, and require extensive optimization. Here, we provide a simple and reproducible enrichment procedure for PM proteins from Arabidopsis thaliana seedlings starting from total microsomal membranes isolated by differential centrifugation. To enrich for PM proteins, total microsomes are treated with the nonionic detergent Brij-58 to decrease the abundance of contaminating organellar proteins. This protocol combined with the genetic resources available in Arabidopsis provides a powerful tool that will enhance our understanding of proteins at the PM.

Self-Assembly of Helical Ribbons

NASA Astrophysics Data System (ADS)

Zastavker, Yevgeniya V.; Asherie, Neer; Lomakin, Aleksey; Pande, Jayanti; Donovan, Joanne M.; Schnur, Joel M.; Benedek, George B.

1999-07-01

The self-assembly of helical ribbons is examined in a variety of multicomponent enantiomerically pure systems that contain a bile salt or a nonionic detergent, a phosphatidylcholine or a fatty acid, and a steroid analog of cholesterol. In almost all systems, two different pitch types of helical ribbons are observed: high pitch, with a pitch angle of 54± 2 degrees, and low pitch, with a pitch angle of 11± 2 degrees. Although the majority of these helices are right-handed, a small proportion of left-handed helices is observed. Additionally, a third type of helical ribbon, with a pitch angle in the range 30-47 degrees, is occasionally found. These experimental findings suggest that the helical ribbons are crystalline rather than liquid crystal in nature and also suggest that molecular chirality may not be the determining factor in helix formation. The large yields of helices produced will permit a systematic investigation of their individual kinetic evolution and their elastic moduli.

pH-sensitive niosomes: Effects on cytotoxicity and on inflammation and pain in murine models.

PubMed

Rinaldi, Federica; Del Favero, Elena; Rondelli, Valeria; Pieretti, Stefano; Bogni, Alessia; Ponti, Jessica; Rossi, François; Di Marzio, Luisa; Paolino, Donatella; Marianecci, Carlotta; Carafa, Maria

2017-12-01

pH-sensitive nonionic surfactant vesicles (niosomes) by polysorbate-20 (Tween-20) or polysorbate-20 derivatized by glycine (added as pH sensitive agent), were developed to deliver Ibuprofen (IBU) and Lidocaine (LID). For the physical-chemical characterization of vesicles (mean size, size distribution, zeta potential, vesicle morphology, bilayer properties and stability) dynamic light scattering (DLS), small angle X-ray scattering and fluorescence studies were performed. Potential cytotoxicity was evaluated on immortalized human keratinocyte cells (HaCaT) and on immortalized mouse fibroblasts Balb/3T3. In vivo antinociceptive activity (formalin test) and anti-inflammatory activity tests (paw edema induced by zymosan) in murine models were performed on drug-loaded niosomes. pH-sensitive niosomes were stable in the presence of 0 and 10% fetal bovine serum, non-cytotoxic and able to modify IBU or LID pharmacological activity in vivo. The synthesis of stimuli responsive surfactant, as an alternative to add pH-sensitive molecules to niosomes, could represent a promising delivery strategy for anesthetic and anti-inflammatory drugs.

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.

[Effect of concomitant substances and addition order on the adsorption of Tween 80 on sand].

PubMed

Xu, Wei; Zhao, Yong-sheng; Li, Sui; Dai, Ning

2008-08-01

Adsorption of Tween 80 on sand was investigated, and the effect of inorganic salts (CaCl2), anionic surfactant (SDS) and lignosulphonates (sodium lignosulphonate or ammonium lignosulphonate) on the adsorption of Tween 80 on sand were evaluated at 25 degrees C. The results show that saturated adsorption amount of Tween 80 on sand enhance when CaCl2 or SDS is added into flushing solution of Tween 80. And the adsorption of Tween 80 on sand increase with the increase of molar fraction of CaCl2 or SDS in mixed flushing solution. And adsorption amount of Tween 80 on sand also enhance when SDS is added into sand firstly. The effects of mixing ratios and addition order of lignosulphonates on adsorption of Tween 80 were considered. The results show that with the increase of molar fraction of lignosulphonates in mixing flushing solution, adsorption amount of Tween 80 on sand decrease. The adsorption amount of Tween 80 reduce 20%-75% due to the exist of ammonium lignosulphonate is superior to sodium lignosulphonate (10%-60%) when mix the lignosulphonates-Tween 80 at the total mass ratios of 1:10, while the adsorption amount of Tween 80 reduce 70%-90% at the total mass ratios of 1:2. Lignosulphonates added into sand firstly is more efficient than that together. Therefore,use of lignosulphonates as a preflush can reduce the adsorption of surfactants on sand and is a better method to applied in in situ flushing.

Fourier transform infrared spectroscopic study of the interactions of a strongly antimicrobial but weakly hemolytic analogue of gramicidin S with lipid micelles and lipid bilayer membranes.

PubMed

Lewis, Ruthven N A H; Kiricsi, Monika; Prenner, Elmar J; Hodges, Robert S; McElhaney, Ronald N

2003-01-21

Cyclo[VKLdKVdYPLKVKLdYP] (GS14dK(4)), a synthetic tetradecameric ring-size analogue of the naturally occurring antimicrobial peptide gramicidin S (GS), retains the strong antimicrobial activity of GS but is 15-20 times less hemolytic. To characterize its interaction with lipid membranes and to understand the molecular basis of its capacity to lyse bacterial cells, in preference to erythrocytes, we have investigated the interactions of GS14dK(4) with detergent micelles and with lipid bilayer model membranes by Fourier transform infrared spectroscopy and compared our results with those of a similar study of GS [Lewis, R. N. A. H., et al. (1999) Biochemistry 38, 15193-15203]. In both aqueous and organic solvent solutions, GS14dK(4) adopts a beta-sheet conformation that is somewhat distorted and more sensitive to the polarity of its environment than GS. Like GS, GS14dK(4) is completely or partially excluded from gel-state lipid bilayers but interacts strongly with liquid-crystalline lipid bilayers and detergent micelle, and interacts more strongly with more fluid liquid-crystalline lipid systems. However, its interactions are more strongly influenced by membrane lipid order and fluidity, and unlike GS, it is essentially excluded from cholesterol-containing phospholipid bilayers. Also, GS14dK(4) is excluded from cationic lipid bilayers, but partitions more strongly and/or penetrates more deeply into anionic lipid bilayers than into those composed of either zwitterionic or nonionic lipids. Anionic lipids also facilitate GS14dK(4) interactions with multicomponent lipid bilayers which are predominantly zwitterionic or nonionic. Although GS14dK(4) generally penetrates and/or partitions into zwitterionic or uncharged lipid bilayers less strongly than does GS, its greater size and altered distribution of positive charges make it intrinsically more perturbing with regard to membrane organization once associated with lipid bilayers. This fact, combined with its relatively strong interactions with anionic phospholipids, may explain why GS14dK(4) retains relatively high antimicrobial activity. However, its low hemolytic activity is probably largely attributable to its low propensity to penetrate and/or partition into cholesterol-containing zwitterionic lipid membranes.

Metabolic Labeling and Membrane Fractionation for Comparative Proteomic Analysis of Arabidopsis thaliana Suspension Cell Cultures

PubMed Central

Szymanski, Witold G.; Kierszniowska, Sylwia; Schulze, Waltraud X.

2013-01-01

Plasma membrane microdomains are features based on the physical properties of the lipid and sterol environment and have particular roles in signaling processes. Extracting sterol-enriched membrane microdomains from plant cells for proteomic analysis is a difficult task mainly due to multiple preparation steps and sources for contaminations from other cellular compartments. The plasma membrane constitutes only about 5-20% of all the membranes in a plant cell, and therefore isolation of highly purified plasma membrane fraction is challenging. A frequently used method involves aqueous two-phase partitioning in polyethylene glycol and dextran, which yields plasma membrane vesicles with a purity of 95% 1. Sterol-rich membrane microdomains within the plasma membrane are insoluble upon treatment with cold nonionic detergents at alkaline pH. This detergent-resistant membrane fraction can be separated from the bulk plasma membrane by ultracentrifugation in a sucrose gradient 2. Subsequently, proteins can be extracted from the low density band of the sucrose gradient by methanol/chloroform precipitation. Extracted protein will then be trypsin digested, desalted and finally analyzed by LC-MS/MS. Our extraction protocol for sterol-rich microdomains is optimized for the preparation of clean detergent-resistant membrane fractions from Arabidopsis thaliana cell cultures. We use full metabolic labeling of Arabidopsis thaliana suspension cell cultures with K15NO3 as the only nitrogen source for quantitative comparative proteomic studies following biological treatment of interest 3. By mixing equal ratios of labeled and unlabeled cell cultures for joint protein extraction the influence of preparation steps on final quantitative result is kept at a minimum. Also loss of material during extraction will affect both control and treatment samples in the same way, and therefore the ratio of light and heave peptide will remain constant. In the proposed method either labeled or unlabeled cell culture undergoes a biological treatment, while the other serves as control 4. PMID:24121251

Preparation of Tween 80-Zn/Al-Levodopa-Layered Double Hydroxides Nanocomposite for Drug Delivery System

PubMed Central

Kura, Aminu Umar; Hussein-Al-Ali, Samer Hasan; Hussein, Mohd Zobir; Fakurazi, Sharida

2014-01-01

We incorporated anti-Parkinsonian drug, levodopa (dopa), in Zn/Al-LDH by coprecipitation method to form dopa-LDH nanocomposite. Further coating of Tween-80 on the external surfaces of dopa-LDH nanocomposite was achieved through the oxygen of C=O group of Tween-80 with the layer of dopa-LDH nanocomposite. The final product is called Tween-dopa-LDH nanocomposite. The X-ray diffraction indicates that the Tween-dopa-LDH nanocomposite was formed by aggregation structure. From the TGA data, the Tween-80 loading on the surface of LDH and dopa-LDH was 8.6 and 7.4%, respectively. The effect of coating process on the dopa release from Tween-dopa-LDH nanocomposite was also studied. The release from Tween-dopa-LDH nanocomposite shows slower release compared to the release of the drug from dopa-LDH nanocomposite as done previously in our study, presumably due to the retarding shielding effect. The cell viability study using PC12 showed improved viability with Tween-80 coating on dopa-LDH nanocomposite as studied by mitochondrial dehydrogenase activity (MTT assay). PMID:24782658

Purification and biochemical characterization of a thermostable and acid-stable alpha-amylase from Bacillus licheniformis B4-423.

PubMed

Wu, Xiangrong; Wang, Yuxia; Tong, Bending; Chen, Xianghua; Chen, Jianhua

2018-04-01

Novel thermostable amylase need to be continuously explored with the improvement of industrial requirements. A new acidophilic and thermostable amylase producing bacterium isolated from spring was identified as Bacillus strain on the basis of 16S rDNA. The amylase was purified by ammonium sulphate precipitation, gel chromatography and anion exchange chromatography. SDS-PAGE revealed that the enzyme was monomeric with a molecular weight of 58 kDa. The amylase exhibited optimal activity at pH 5.0 and temperature 100 °C. Then the enzyme showed high stability in pH ranges 4.0-10.0 and more than 90% of maximal activity was found from 20 °C to 80 °C. Apart from good stability toward SDS and non-ionic detergent, the purified enzyme exhibited high compatibility with some inhibitors such as urea and EDTA. The results demonstrated the stability of the enzyme in different organic solvents. Moreover, we determined the amylase gene, compared the structure with α-amylase BAA and BLA and found some thermostability determinants in our enzyme. Overall, presenting various properties were including high thermostability, Ca 2+ -independency, broad temperature and pH profiles, organic-solvent tolerance as well as excellent stability with detergents. Such characteristics have not been reported for this type of enzyme, and the α-amylase will be a suitable candidate in industrial fields. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of different polysorbates on development of self-microemulsifying drug delivery systems using medium chain lipids.

PubMed

Shah, Ankita; Thool, Prajwal; Sorathiya, Komal; Prajapati, Hetal; Dalrymple, Damon; Serajuddin, Abu T M

2018-02-01

The primary objective of this study was to develop lipid-based self-microemulsifying drug delivery systems (SMEDDS) without using any organic cosolvents that would spontaneously form microemulsions upon dilution with water. Cosolvents were avoided to prevent possible precipitation of drug upon dilution and other stability issues. Different polysorbates, namely, Tween 20, Tween 40, Tween 60, and Tween 80, were used as surfactants, and Captex 355 EP/NF (glycerol tricaprylate/caprate) or its 1:1 mixture with Capmul MCM NF (glycerol monocaprylocaprate) were used as lipids. Captex 355-Tween-water ternary phase diagrams showed that oil-in-water microemulsions were formed only when the surfactant content was high (80-90%) and the lipid content low (10-20%). Thus, mixtures of Tweens with Captex 355 alone were not suitable to prepare SMEDDS with substantial lipid contents. However, when Captex 355 was replaced with the 1:1 mixture of Captex 355 and Capmul MCM, clear isotropic microemulsion regions in phase diagrams with sizes in the increasing order of Tween 20 < Tween 40 < Tween 60 < Tween 80 were obtained. Tween 80 had the most profound effect among all surfactants as microemulsions were formed with lipid to surfactant ratios as high as 7:3, which may be attributed to the presence of double bond in its side chain that increased the curvature of surfactant layer. Thus, lipid-surfactant mixtures containing 1:1 mixture of medium chain triglyceride (Captex 355) and monoglyceride (Capmul MCM) and as low as 30% Tween 80 were identified as organic cosolvent-free systems for the preparation of SMEDDS. Formulations with a model drug, probucol, dispersed spontaneously and rapidly upon dilution with water to form microemulsions without any drug precipitation.

[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.

Rapid preparation of nuclei-depleted detergent-resistant membrane fractions suitable for proteomics analysis.

PubMed

Adam, Rosalyn M; Yang, Wei; Di Vizio, Dolores; Mukhopadhyay, Nishit K; Steen, Hanno

2008-06-05

Cholesterol-rich membrane microdomains known as lipid rafts have been implicated in diverse physiologic processes including lipid transport and signal transduction. Lipid rafts were originally defined as detergent-resistant membranes (DRMs) due to their relative insolubility in cold non-ionic detergents. Recent findings suggest that, although DRMs are not equivalent to lipid rafts, the presence of a given protein within DRMs strongly suggests its potential for raft association in vivo. Therefore, isolation of DRMs represents a useful starting point for biochemical analysis of lipid rafts. The physicochemical properties of DRMs present unique challenges to analysis of their protein composition. Existing methods of isolating DRM-enriched fractions involve flotation of cell extracts in a sucrose density gradient, which, although successful, can be labor intensive, time consuming and results in dilute sucrose-containing fractions with limited utility for direct proteomic analysis. In addition, several studies describing the proteomic characterization of DRMs using this and other approaches have reported the presence of nuclear proteins in such fractions. It is unclear whether these results reflect trafficking of nuclear proteins to DRMs or whether they arise from nuclear contamination during isolation. To address these issues, we have modified a published differential detergent extraction method to enable rapid DRM isolation that minimizes nuclear contamination and yields fractions compatible with mass spectrometry. DRM-enriched fractions isolated using the conventional or modified extraction methods displayed comparable profiles of known DRM-associated proteins, including flotillins, GPI-anchored proteins and heterotrimeric G-protein subunits. Thus, the modified procedure yielded fractions consistent with those isolated by existing methods. However, we observed a marked reduction in the percentage of nuclear proteins identified in DRM fractions isolated with the modified method (15%) compared to DRMs isolated by conventional means (36%). Furthermore, of the 21 nuclear proteins identified exclusively in modified DRM fractions, 16 have been reported to exist in other subcellular sites, with evidence to suggest shuttling of these species between the nucleus and other organelles. We describe a modified DRM isolation procedure that generates DRMs that are largely free of nuclear contamination and that is compatible with downstream proteomic analyses with minimal additional processing. Our findings also imply that identification of nuclear proteins in DRMs is likely to reflect legitimate movement of proteins between compartments, and is not a result of contamination during extraction.

Acute pulmonary pathology and sudden death in rats following the intravenous administration of the plasticizer, DI (2-ethylhexyl) phthalate, solubilized with Tween surfactants. [pathology of vinyl plastics poisoning

NASA Technical Reports Server (NTRS)

Schulz, C. O.; Rubin, R. J.; Hutchins, G. M.

1975-01-01

Intravenous administration of 200-300 mg/kg of di(2-ethylhexyl)phthalate (DEHP) solubilized in aqueous solutions of several Tween surfactants caused respiratory distress in rats. There was a dose-dependent lethality with death generally occurring within 90 minutes after injection. The lungs from DEHP:Tween treated animals were enlarged, generally darkened, and in some cases showed hemorrhagic congestion. Neither the overt symptoms nor the morphologic alterations resulting from DEHP:Tween administration could be reproduced by intravenous administration of aqueous Tween solutions alone. The absence of pulmonary abnormalities following the intravenous administration of DEHP as an aqueous emulsion given either alone or even as soon as 2 minutes after pretreatment with Tween 80, suggests that the specific in vivo interaction between DEHP and Tween surfactants depends on the prior formation of water-soluble micelles of DEHP.

Depicting Femininity: Conflicting Messages in a "Tween" Magazine

ERIC Educational Resources Information Center

Velding, Victoria

2017-01-01

Femininity is learned from a myriad of social agents and institutions. An avid consumer of media, today's pre-adolescent girl, or "tween," is inundated with messages about how to be a socially acceptable female. What is the nature of these messages tweens are receiving about femininity? Are tween girls in today's society encouraged to…

Highly antioxidant carotene-lipid nanocarriers: synthesis and antibacterial activity

NASA Astrophysics Data System (ADS)

Lacatusu, Ioana; Badea, Nicoleta; Ovidiu, Oprea; Bojin, Dionezie; Meghea, Aurelia

2012-06-01

The objective of this study was to explore the potential of two natural oils (squalene—Sq and grape seed oil—GSO) to prepare biocompatible antioxidant nanostructured lipid carriers—NLCs as a safety and protective formulation for sensitive β-carotene. For this purpose different oil-in-water nanoemulsions stabilized by a combination of alkylpolyoxy ethylene sorbitans, lecithin and a block copolymer, were prepared using a melt high-shear homogenization process. The physico-chemical characteristics of the carotene-loaded NLCs were firstly investigated in detail. The smaller lipid nanoparticles have been obtained by using Tween 20 as main non-ionic surfactant, with average diameters of about 85 nm for GSO and 89 nm for Sq, with a polydispersity index <0.19. The developed carotene-NLCs presented an excellent physical stability with almost all zeta potential values ranging between -29 ÷ -40 mV. The differential scanning calorimetry analysis showed that the β-carotene incorporation has led to a perturbation of solid lipid matrix with a less ordered arrangement. By UV-Vis spectroscopy it was evidenced that after encapsulation β-carotene adopts a supramolecular structure demonstrated by appearance of a shoulder at 530 nm related to a β-carotene triplet-triplet absorption. The carotene-NLCs have been also evaluated in terms of in vitro antioxidant properties. The presence of Sq and GSO produced a significant effect on the antioxidant capacity of developed NLCs. The samples prepared with GSO and Tween 80 as main surfactant showed the highest antioxidant activity (AA %) against free oxygen radicals, exhibiting an enhancement of 35 % for loaded NLCs, as comparing to pure carotene. In addition to these properties, the ability of NLCs to manifest antibacterial activity was tested against Escherichia coli bacteria. The antibacterial analysis shown that loaded-NLCs develop an effective inhibition zone against bacteria growth and it was dependent in a higher extent on the liquid lipid and carotene concentrations than on their particle size.

Ionic liquid-in-oil microemulsion as a potential carrier of sparingly soluble drug: characterization and cytotoxicity evaluation.

PubMed

Moniruzzaman, Muhammad; Tamura, Miki; Tahara, Yoshiro; Kamiya, Noriho; Goto, Masahiro

2010-11-15

Pharmaceutical industries have posed challenges in the topical and transdermal administration of drugs which are poorly soluble or insoluble in water and most of organic solvents. In an approach to overcome this limitation, ionic liquid-in-oil (IL/o) microemulsions (MEs) were employed to increase the solubility of a sparingly soluble drug to enhance its topical and transdermal delivery. The formulation of MEs was composed of a blend of nonionic surfactants, polyoxyethylene sorbitan monooleate (Tween-80) and sorbitan laurate (Span-20), isopropyl myristate (IPM) as an oil phase, and IL [C(1)mim] [(CH(3)O)(2)PO(2)] (dimethylimidazolium dimethylphosphate) as a pseudophase. Among various weight ratios of Tween-80 to Span-20 investigated in the ME systems, the ratio 3:2 showed excellent solubility and skin permeation enhancing effect for acyclovir (ACV) used as a model sparingly soluble drug. The size and size distribution of the ME droplets with and without drug were determined by dynamic light scattering. The permeability study of ACV incorporated in IL droplets as well as other formulations was performed into and across the Yucatan micropig (YMP) porcine skin, and the use of IL/o MEs has been shown to dramatically increase ACV administration. Finally, the cytotoxicity of the new carrier was evaluated in vitro using the reconstructed human epidermal model LabCyte™ EPI-MODEL12. It was found that the cell viability of IL/o MEs containing 4wt% IL was over 80% compared to Dulbecco's Phosphate-Buffered Salines, indicating low cytotoxicity of the carrier. Taken together these results, it can be assumed that IL-assisted nonaqueous ME could serve as a versatile and efficient nanodelivery system for insoluble or sparingly soluble drug molecules that require solubilizing agents for delivery. Copyright © 2010 Elsevier B.V. All rights reserved.

Differential effects of dissolved organic carbon upon re-entrainment and surface properties of groundwater bacteria and bacteria-sized microspheres during transport through a contaminated, sandy aquifer

USGS Publications Warehouse

Harvey, R.W.; Metge, D.W.; Mohanram, A.; Gao, X.; Chorover, J.

2011-01-01

Injection-and-recovery studies involving a contaminated, sandy aquifer (Cape Cod, Massachusetts) were conducted to assess the relative susceptibility for in situ re-entrainment of attached groundwater bacteria (Pseudomonas stuzeri ML2, and uncultured, native bacteria) and carboxylate-modified microspheres (0.2 and 1.0 μm diameters). Different patterns of re-entrainment were evident for the two colloids in response to subsequent injections of groundwater (hydrodynamic perturbation), deionized water (ionic strength alteration), 77 μM linear alkylbenzene sulfonates (LAS, anionic surfactant), and 76 μM Tween 80 (polyoxyethylene sorbitan monooleate, a very hydrophobic nonionic surfactant). An injection of deionized water was more effective in causing detachment of micrsopheres than were either of the surfactants, consistent with the more electrostatic nature of microsphere’s attachment, their extreme hydrophilicity (hydrophilicity index, HI, of 0.99), and negative charge (zeta potentials, ζ, of −44 to −49 mv). In contrast, Tween 80 was considerably more effective in re-entraining the more-hydrophobic native bacteria. Both the hydrophilicities and zeta potentials of the native bacteria were highly sensitive to and linearly correlated with levels of groundwater dissolved organic carbon (DOC), which varied modestly from 0.6 to 1.3 mg L−1. The most hydrophilic (0.52 HI) and negatively charged (ζ −38.1 mv) indigenous bacteria were associated with the lowest DOC. FTIR spectra indicated the latter community had the highest average density of surface carboxyl groups. In contrast, differences in groundwater (DOC) had no measurable effect on hydrophilicity of the bacteria-sized microspheres and only a minor effect on their ζ. These findings suggest that microspheres may not be very good surrogates for bacteria in field-scale transport studies and that adaptive (biological) changes in bacterial surface characteristics may need to be considered where there is longer-term exposure to contaminant DOC.

Biochemical and molecular characterization of a detergent-stable serine alkaline protease from Bacillus pumilus CBS with high catalytic efficiency.

PubMed

Jaouadi, Bassem; Ellouz-Chaabouni, Semia; Rhimi, Moez; Bejar, Samir

2008-09-01

We have described previously the potential use of an alkaline protease from Bacillus pumilus CBS as an effective additive in laundry detergent formulations [B. Jaouadi, S. Ellouz-Chaabouni, M. Ben Ali, E. Ben Messaoud, B. Naili, A. Dhouib, S. Bejar, A novel alkaline protease from Bacillus pumilus CBS having a high compatibility with laundry detergent and a high feather-degrading activity, Process Biochem, submitted for publication]. Here, we purified this enzyme (named SAPB) and we cloned, sequenced and over-expressed the corresponding gene. The enzyme was purified to homogeneity using salt precipitation and gel filtration HPLC. The pure protease was found to be monomeric protein with a molecular mass of 34598.19Da as determined by MALDI-TOF mass spectrometry. The NH2-terminal sequence of first 21 amino acids (aa) of the purified SAPB was AQTVPYGIPQIKAPAVHAQGY and was completely identical to proteases from other Bacillus pumilus species. This protease is strongly inhibited by PMSF and DFP, showing that it belongs to the serine proteases superfamily. Interestingly, the optimum pH is 10.6 while the optimum temperature was determined to be 65 degrees C. The enzyme was completely stable within a wide range of pH (7.0-10.6) and temperature (30-55 degrees C). One of the distinguishing properties is its catalytic efficiency (kcat/Km) calculated to be 45,265min(-1)mM(-1) and 147,000min(-1)mM(-1) using casein and AAPF as substrates, respectively, which is higher than that of Subtilisin Carlsberg, Subtilisin BPN' and Subtilisin 309 determined under the same conditions. In addition, SAPB showed remarkable stability, for 24h at 40 degrees C, in the presence of 5% Tween-80, 1% SDS, 15% urea and 10% H2O2, which comprise the common bleach-based detergent formulation. The sapB gene encoding SAPB was cloned, sequenced and over-expressed in Escherichia coli. The purified recombinant enzyme (rSAPB) has the same physicochemical and kinetic properties as the native one. SapB gene had an ORF of 1149bp encoding a protein of 383 aa organized into a signal peptide (29 aa), a pro-protein (79 aa) and a mature enzyme (275 aa). The deduced amino acid sequence inspection displays an important homology with other bacterial proteases. The highest homology of 98.1% was found with BPP-A protease from Bacillus pumilus MS-1, with only 8 aa of difference.

Formulation and evaluation of carrot seed oil-based cosmetic emulsions.

PubMed

Singh, Shalini; Lohani, Alka; Mishra, Arun Kumar; Verma, Anurag

2018-05-08

The present study deals with the evaluation of antiaging potential of carrot seed oil-based cosmetic emulsions. Briefly, cosmetic emulsions composed of carrot seed oil in varying proportions (2, 4, and 6% w/v) were prepared using the hydrophile-lipophile balance (HLB) technique. Coconut oil, nonionic surfactants (Tween 80 and Span 80), and xanthan gum were used as the oil phase, emulgent, and emulsion stabilizer, respectively. The formed emulsions were evaluated for various physical, chemical, and biochemical parameters such as the zeta potential, globule size measurement, antioxidant activity, sun protection factor (SPF), skin irritation, and biochemical studies. The zeta potential values ranged from -43.2 to -48.3, indicating good stability. The polydispersity index (PDI) of various emulsion formulations ranged from 0.353 to 0.816. 1,1-Diphenyl-2-picrylhydrazyl- (DPPH) and nitric oxide-free radical scavenging activity showed the antioxidant potential of the prepared carrot seed oil emulsions. The highest SPF value (6.92) was shown by F3 having 6%w/v carrot seed oil. Histopathological data and biochemical analysis (ascorbic acid (ASC) and total protein content) suggest that these cosmetic emulsions have sufficient potential to be used as potential skin rejuvenating preparations.

Physicochemical Characterization and Thermodynamic Studies of Nanoemulsion-Based Transdermal Delivery System for Fullerene

PubMed Central

Basri, Mahiran; Tripathy, Minaketan; Abdul-Malek, Emilia

2014-01-01

Fullerene nanoemulsions were formulated in palm kernel oil esters stabilized by low amount of mixed nonionic surfactants. Pseudoternary phase diagrams were established in the colloidal system of PKOEs/Tween 80 : Span 80/water incorporated with fullerene as antioxidant. Preformulation was subjected to combination of high and low energy emulsification methods and the physicochemical characteristics of fullerene nanoemulsions were analyzed using electroacoustic spectrometer. Oil-in-water (O/W) nanoemulsions with particle sizes in the range of 70–160 nm were formed. The rheological characteristics of colloidal systems exhibited shear thinning behavior which fitted well into the power law model. The effect of xanthan gum (0.2–1.0%, w/w) and beeswax (1–3%, w/w) in the estimation of thermodynamics was further studied. From the energetic parameters calculated for the viscous flow, a moderate energy barrier for transport process was observed. Thermodynamic study showed that the enthalpy was positive in all xanthan gum and beeswax concentrations indicating that the formation of nanoemulsions could be endothermic in nature. Fullerene nanoemulsions with 0.6% or higher xanthan gum content were found to be stable against creaming and flocculation when exposed to extreme environmental conditions. PMID:25165736

Niosomes as a vesicular carrier for topical administration of minoxidil: formulation and in vitro assessment.

PubMed

Mali, Nitin; Darandale, Sharad; Vavia, Pradeep

2013-12-01

Niosomes are reported to increase the skin permeation and bioavailability of topically applied drug molecules. However, very few studies were reported for nanometer-sized niosome vesicles. The aim of the present study was to prepare minoxidil-loaded niosomal formulation using ethanol injection method. Surfactant screening showed that only Span 60, Span 20, and Tween 20 with cholesterol have capability of nano size vesicle formation. The formed niosomes were characterized for entrapment efficiency, vesicle size, scanning electron microscope, and physical stability. By modulation of surfactant and cholesterol ratio maximum entrapment up to 34.70 ± 1.1 % with size of 470 ± 27 nm was obtained (Span 60/cholesterol ratio of 1:2). The vesicle size obtained was between 150 and 800 nm that was depending on cholesterol ratio and type of nonionic surfactant employed. The in vitro skin permeation study showed that an increase in cholesterol concentration in niosome vesicles increases minoxidil skin retention. Niosome formulation prepared with 1:2 ratio of Span 60 and cholesterol showed 17.21 ± 3.2 % skin retention of minoxidil, which is more than eightfold as compared to control minoxidil gel.

Surfactant-enhanced anaerobic acidogenesis of Canna indica L. by rumen cultures.

PubMed

Yue, Zheng-Bo; Yu, Han-Qing; Hu, Zhen-Hu; Harada, Hideki; Li, Yu-You

2008-06-01

Polyoxyethylene sorbitan monoolate (Tween 80) was used to enhance the anaerobic acidogenesis of Canna indica L. (canna) by rumen culture in this study. Dose of Tween 80 at 1 ml/l enhanced the volatile fatty acids (VFA) production from the acidogenesis of canna compared to the control. However, Tween 80 at higher dosages than 5 ml/l inhibited the rumen microbial activity and reduced the VFA yield. Response surface methodology was successfully used to optimize the VFA yield. A maximum of VFA yield of 0.147 g/g total solids (TS) added was obtained at canna and Tween 80 concentrations of 6.3g TS/l and 2.0 ml/l, respectively. Dosage of Tween 80 at 1-3.75 ml/l reduced the unproductive adsorption of microbes or enzymes on the lignin part in canna and increased microbial activity. A high VFA production was achieved from canna presoaked with Tween 80, suggesting that the structure of canna was disrupted by Tween 80.

An ammonium sulfate sensitive endoxylanase produced by Streptomyces.

PubMed

Simkhada, Jaya Ram; Yoo, Hah Young; Park, Don Hee; Choi, Yun Hee; Lee, Hyo Jeong; Kim, Seung Wook; Yoo, Jin Cheol

2013-06-01

Streptomyces sp. CSWu2 was newly isolated and identified from Korean soil. In culture medium, the strain produced a highly active endoxylanase (Xynwu2), which was purified to homogeneity by a single-step chromatography on Poros-HQ. The xylanase was ~38 kDa and its activity was maximal at 65 °C and pH 11.0. It was stable up to 60 °C and from pH 8.0 to 12.0, and its activity was slightly enhanced by nonionic detergents, but inhibited by EDTA, EGTA, and divalent metal ions. Intriguingly, Xynwu2 was highly sensitive to ammonium sulfate, but its completely suppressed activity was recovered by desalting out. Xynwu2 produced xylose and xylobiose as principal end products from xylan, suggesting an endoxylanase nature. Importantly, scanning electron microscopy showed Xynwu2 efficiently degraded corncobs, an agro-industrial waste material. We believe that Xynwu2 is a potential candidate for converting lignocellulosic waste material into simple sugars which could be used to produce bioethanol and other value-added products.

Plasmid DNA production combining antibiotic-free selection, inducible high yield fermentation, and novel autolytic purification.

PubMed

Carnes, Aaron E; Hodgson, Clague P; Luke, Jeremy M; Vincent, Justin M; Williams, James A

2009-10-15

DNA vaccines and gene medicines, derived from bacterial plasmids, are emerging as an important new class of pharmaceuticals. However, the challenges of performing cell lysis processes for plasmid DNA purification at an industrial scale are well known. To address downstream purification challenges, we have developed autolytic Escherichia coli host strains that express endolysin (phage lambdaR) in the cytoplasm. Expression of the endolysin is induced during fermentation by a heat inducible promoter. The endolysin remains in the cytoplasm, where it is separated from its peptidoglycan substrate in the cell wall; hence the cells remain alive and intact and can be harvested by the usual methods. The plasmid DNA is then recovered by autolytic extraction under slightly acidic, low salt buffer conditions and treatment with a low concentration of non-ionic detergent. Under these conditions the E. coli genomic DNA remains associated with the insoluble cell debris and is removed by a solid-liquid separation. Here, we report fermentation, lysis methods, and plasmid purification using autolytic hosts.

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.

Modeling micelle formation and interfacial properties with iSAFT classical density functional theory

NASA Astrophysics Data System (ADS)

Wang, Le; Haghmoradi, Amin; Liu, Jinlu; Xi, Shun; Hirasaki, George J.; Miller, Clarence A.; Chapman, Walter G.

2017-03-01

Surfactants reduce the interfacial tension between phases, making them an important additive in a number of industrial and commercial applications from enhanced oil recovery to personal care products (e.g., shampoo and detergents). To help obtain a better understanding of the dependence of surfactant properties on molecular structure, a classical density functional theory, also known as interfacial statistical associating fluid theory, has been applied to study the effects of surfactant architecture on micelle formation and interfacial properties for model nonionic surfactant/water/oil systems. In this approach, hydrogen bonding is explicitly included. To minimize the free energy, the system minimizes interactions between hydrophobic components and hydrophilic components with water molecules hydrating the surfactant head group. The theory predicts micellar structure, effects of surfactant architecture on critical micelle concentration, aggregation number, and interfacial tension isotherm of surfactant/water systems in qualitative agreement with experimental data. Furthermore, this model is applied to study swollen micelles and reverse swollen micelles that are necessary to understand the formation of a middle-phase microemulsion.

Synthesis, characterization, applications, and challenges of iron oxide nanoparticles

PubMed Central

Ali, Attarad; Zafar, Hira; Zia, Muhammad; ul Haq, Ihsan; Phull, Abdul Rehman; Ali, Joham Sarfraz; Hussain, Altaf

2016-01-01

Recently, iron oxide nanoparticles (NPs) have attracted much consideration due to their unique properties, such as superparamagnetism, surface-to-volume ratio, greater surface area, and easy separation methodology. Various physical, chemical, and biological methods have been adopted to synthesize magnetic NPs with suitable surface chemistry. This review summarizes the methods for the preparation of iron oxide NPs, size and morphology control, and magnetic properties with recent bioengineering, commercial, and industrial applications. Iron oxides exhibit great potential in the fields of life sciences such as biomedicine, agriculture, and environment. Nontoxic conduct and biocompatible applications of magnetic NPs can be enriched further by special surface coating with organic or inorganic molecules, including surfactants, drugs, proteins, starches, enzymes, antibodies, nucleotides, nonionic detergents, and polyelectrolytes. Magnetic NPs can also be directed to an organ, tissue, or tumor using an external magnetic field for hyperthermic treatment of patients. Keeping in mind the current interest in iron NPs, this review is designed to report recent information from synthesis to characterization, and applications of iron NPs. PMID:27578966

Nuclear matrix - structure, function and pathogenesis.

PubMed

Wasąg, Piotr; Lenartowski, Robert

2016-12-20

The nuclear matrix (NM), or nuclear skeleton, is the non-chromatin, ribonucleoproteinaceous framework that is resistant to high ionic strength buffers, nonionic detergents, and nucleolytic enzymes. The NM fulfills a structural role in eukaryotic cells and is responsible for maintaining the shape of the nucleus and the spatial organization of chromatin. Moreover, the NM participates in several cellular processes, such as DNA replication/repair, gene expression, RNA transport, cell signaling and differentiation, cell cycle regulation, apoptosis and carcinogenesis. Short nucleotide sequences called scaffold/matrix attachment regions (S/MAR) anchor the chromatin loops to the NM proteins (NMP). The NMP composition is dynamic and depends on the cell type and differentiation stage or metabolic activity. Alterations in the NMP composition affect anchoring of the S/MARs and thus alter gene expression. This review aims to systematize information about the skeletal structure of the nucleus, with particular emphasis on the organization of the NM and its role in selected cellular processes. We also discuss several diseases that are caused by aberrant NM structure or dysfunction of individual NM elements.

Mycobacteriocins produced by rapidly growing mycobacteria are Tween-hydrolyzing esterases.

PubMed Central

Saito, H; Tomioka, H; Watanabe, T; Yoneyama, T

1983-01-01

Smegmatocin, a protein produced by Mycobacterium smegmatis ATCC 14468, was found to have an esterase activity, hydrolyzing Tween 80, polyoxyethylene sorbitan monooleate, added to the assay medium for various "bacteriocins" from mycobacteria. Because M. diernhoferi ATCC 19340 (indicator strain for smegmatocin) is highly susceptible to oleic acid and smegmatocin requires Tween 80 for manifestation of its anti-M. diernhoferi activity, it is likely that smegmatocin-mediated antimicrobial action is caused by oleic acid generated by hydrolysis of Tween 80 by the inherent esterase action of smegmatocin. Other mycobacteriocins from rapidly growing mycobacteria also have inherent esterase activity against Tween 80 and require Tween 80 for expression of antimycobacterial action. Smegmatocin was found to hydrolyze various polyoxyethylene (sorbitan) fatty acyl esters but not sorbitan monooleate and glyceryl esters. Images PMID:6826523

Radioiodinated cholesteryl ester analogs as residualizing tracers of lipoproteins disposition

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

DeForge, L.E.

1989-01-01

Due to the importance of low density lipoprotein (LDL) in lipid metabolism and atherosclerosis, efforts were made to incorporate {sup 125}I-cholesteryl iopanoate ({sup 125}I-CI), a residualizing cholesteryl ester (CE) analog, into the lipid core of LDL. This preparation is potentially useful as a scintigraphically detectable tracer of LDL uptake into atheroma and tissues such as the adrenal and liver. Initial studies using a cholesterol-fed rabbit model of atherosclerosis validated the use of {sup 125}I-CI as a tracer of CE deposition. However, scintigraphy revealed considerable nonspecific {sup 125}I-CI uptake due to tissue cholesterol loading. An alternative animal model was the guineamore » pig, which responds moderately to cholesterol feeding and carries the plasma cholesterol predominantly as LDL. Dietary fat and cholesterol, coupled with chronic aortic injury caused by an indwelling catheter, resulted in lipid containing, smooth muscle cell proliferative lesions in many animals. However, further studies are necessary to fully characterize this model. In additional studies, in vitro methods for incorporating {sup 125}I-CI into LDL were examined. These included a reconstitution procedure described by Krieger et al. and a procedure involving incubation of detergent (Tween 20)-solubilized {sup 125}I-CI with plasma. Although both LDL preparations were taken up normally by cultured fibroblasts, the plasma clearance rate of reconstituted LDL was markedly abnormal in guinea pigs. In contrast, LDL labeled by the detergent method cleared from the plasma identically to a radioiodinated LDL control. Therefore, this latter procedure was also used to incorporate two novel radioiodinated cholesteryl ether analogs {sup 125}I-CI cholesteryl m-iodobenzyl ether ({sup 125}I-CIDE) and {sup 125}I-cholesteryl 12-(miodophenyl)dodecyl ether ({sup 125}I-CIDE) into LDL.« less

Cost-effective endo-mannanase from Bacillus sp. CFR1601 and its application in generation of oligosaccharides from guar gum and as detergent additive.

PubMed

Srivastava, Praveen Kumar; Kapoor, Mukesh

2014-01-01

The indigenous bacteria Bacillus sp. CFR1601 produced significant levels of endo-mannanase when grown on agro-wastes, namely, green gram husk and sunflower oil cake (25.6 IU/mL), used as sole carbon and nitrogen sources, respectively. Under immobilized cell system, synthetic supports (polyurethane foam, scotch brite, polyester; up to 33.2 IU/mL) were found marginally superior as compared to natural supports (cotton and silk; up to 28.2 IU/mL) for endo-mannanase production. Cooperative interactions between L-lysine HCl (0.3% w/v), Tween 60 (0.3% v/v), and sunflower oil cake (3.0% w/v) in central composite design response surface methodology ameliorated (1.61-fold) endo-mannanase titers to 48.0 IU/mL. Partially purified endo-mannanase was tested for its ability to produce oligosaccharides from guar gum. These oligosaccharides were tested in vitro for their ability to promote growth of Lactobacillus plantarum MTCC 5422 and Lactobacillus salivarius CHS 1E. Results indicated that low-molecular-weight degraded products from guar gum were (1) able to support the growth of tested strains [increased O.D600nm up to 2.3-fold and decrease in pH (<6.3) due to production of short chain fatty acid (SCFA)] when used as sole carbon source; and (2) after purification and analysis by electron spray ionization-mass spectrometry (ESI-MS) were found to be composed of mainly disaccharide and tetrasaccharide. The compatibility of endo-mannanase with various detergents together with wash performance test confirmed its potential applicability for laundry industry.

A Crosslinking Analysis of GAP-43 Interactions with Other Proteins in Differentiated N1E-115 Cells

PubMed Central

Ollom, Callise M.; Denny, John B.

2008-01-01

It has been suggested that GAP-43 (growth-associated protein) binds to various proteins in growing neurons as part of its mechanism of action. To test this hypothesis in vivo, differentiated N1E-115 neuroblastoma cells were labeled with [35S]-amino acids and were treated with a cleavable crosslinking reagent. The cells were lysed in detergent and the lysates were centrifuged at 100,000 × g to isolate crosslinked complexes. Following cleavage of the crosslinks and analysis by two-dimensional gel electrophoresis, it was found that the crosslinker increased the level of various proteins, and particularly actin, in this pellet fraction. However, GAP-43 was not present, suggesting that GAP-43 was not extensively crosslinked to proteins of the cytoskeleton and membrane skeleton and did not sediment with them. GAP-43 also did not sediment with the membrane skeleton following nonionic detergent lysis. Calmodulin, but not actin or other proposed interaction partners, co-immunoprecipitated with GAP-43 from the 100,000 × g supernatant following crosslinker addition to cells or cell lysates. Faint spots at 34 kDa and 60 kDa were also present. Additional GAP-43 was recovered from GAP-43 immunoprecipitation supernatants with anti-calmodulin but not with anti-actin. The results suggest that GAP-43 is not present in complexes with actin or other membrane skeletal or cytoskeletal proteins in these cells, but it is nevertheless possible that a small fraction of the total GAP-43 may interact with other proteins. PMID:19325830

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.

Detachment of trophozoites of Acanthamoeba species from soft contact lenses with BEN22 detergent, BioSoak, and Renu multi-purpose solutions.

PubMed

Raali, E; Vaahtoranta-Lehtonen, H H; Lehtonen, O P

2001-07-01

BEN22 detergent was studied for its ability to detach Acanthamoeba from soft contact lenses without mechanical cleaning or separate cleaning agents. Trophozoites of Acanthamoeba castellanii and A. polyphaga were adhered onto nonionic, high water content soft contact lenses. The lenses were immersed for 2 hours in contact lens care solutions and the remaining trophozoites were counted microscopically. The counts were compared to the counts on the same lens before treatment. BEN22 (50:50 mixture of L-alpha-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate and 2-O-alpha-L-rhamnopyranosyl-alpha-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate) (Kassell Industries, Inc., Wisconsin Dells, WI) in a concentration of 0.05% detached the trophozoites to a statistically significant greater extent than saline, but commercial ReNu Multi-Purpose Solution (Bausch & Lomb, Italy) and BioSoak (Finnsusp Ltd., Finland) did so as well. ReNu Multi-Purpose Solution was more effective than 0.005% BEN22 in detaching the trophozoites of both of the Acanthamoeba strains. After the 2 hour immersion period, a maximum of 97% of the initial trophozoites were detached. The variation between individual lenses was significantly greater than that within the different areas of one lens. BEN22 had no reliable detaching effect on Acanthamoeba. The variation between lenses was great, and the rate of detachment was low with all the agents tested indicating that immersion and rinsing in the solutions tested cannot be considered as a safe substitute for proper disinfection against Acanthamoeba in contact lens care.

Biochemical properties and evaluation of washing performance in commercial detergent compatibility of two collagenolytic serine peptidases secreted by Aspergillus fischeri and Penicillium citrinum.

PubMed

Ida, Érika Lika; da Silva, Ronivaldo Rodrigues; de Oliveira, Tássio Brito; Souto, Tatiane Beltramini; Leite, Juliana Abigail; Rodrigues, André; Cabral, Hamilton

2017-03-16

Filamentous fungi secrete diverse peptidases with different biochemical properties, which is of considerable importance for application in various commercial sectors. In this study, we describe the isolation of two fungal species collected from the soil of decayed organic matter: Aspergillus fischeri and Penicillium citrinum. In a submerged bioprocess, we observed better peptidase production with the fungus P. citrinum, which reached a peak production at 168 h with 760 U/mL, in comparison with the fungus A. fischeri, which reached a peak production at 72 h with 460 U/mL. In both situations, the fermentative medium contained 0.5% crushed feathers as a source of nitrogen. On performing biochemical characterization, we detected two alkaline serine peptidases: The one secreted by P. citrinum had optimal activity at pH 7.0 and at 45°C, while the one secreted by A. fischeri had optimal activity in pH 6.5-8 and at 55-60°C. Metallic ions were effective in modulating these peptidases; in particular, Cu 2+ promoted negative modulation of both peptidases. The peptidases were stable and functional under conditions of nonionic surfactants, temperatures up to 45°C for 1 h, and incubation over a wide pH range. In addition, it was observed that both peptidases had the capacity to hydrolyze collagen and performed well in removing an egg protein stain when supplemented into a commercial powder detergent; this was especially true for the peptidase from P. citrinum.

Improvement of Biodesulfurization Rate of Alginate Immobilized Rhodococcus erythropolis R1

PubMed Central

Derikvand, Peyman; Etemadifar, Zahra

2014-01-01

Background: Sulfur oxides released from the burning of oil causes severe environmental pollution. The sulfur can be removed via the 4S pathway in biodesulfurization (BDS). Immobilization approaches have been developed to prevent cell contamination of oil during the BDS process. Objectives: The encapsulation of Rhodococcus erythropolis R1 in calcium alginate beads was studied in order to enhance conversion of dibenzothiophene (DBT) to 2-hydroxy biphenyl (2-HBP) as the final product. Also the effect of different factors on the BDS process was investigated. Materials and Methods: Calcium alginate capsules were prepared using peristaltic pumps with different needle sizes to control the beads sizes. Scanning electron microscopy and flow cytometry methods were used to study the distribution and viability of encapsulated cells, respectively. Two non-ionic surfactants and also nano Ƴ-Al2O3were used with the ratio of 0.5% (v/v) and 1:5 (v/v) respectively to investigate their BDS efficiency. In addition, the effect of different bead sizes and different concentrations of sodium alginate in BDS activity was studied. Results: The 2% (w/v) sodium alginate beads with 1.5mm size were found to be the optimum for beads stability and efficient 2-HBP production. The viability of encapsulated cells decreased by 12% after 20 h of desulfurization, compared to free cells. Adding the non-ionic surfactants markedly enhanced the rate of BDS, because of increasing mass transfer of DBT to the gel matrix. In addition, Span 80 was more effective than Tween 80. The nanoƳ-Al2O3 particles could increase BDS rate by up to two-folds greater than that of the control beads. Conclusions: The nano Ƴ-Al2O3 can improve the immobilized biocatalyst for excellent efficiency of DBT desulfurization. Also the BDS activity can be enhanced by setting the other explained factors at optimum levels. PMID:25147685

Improvement of Biodesulfurization Rate of Alginate Immobilized Rhodococcus erythropolis R1.

PubMed

Derikvand, Peyman; Etemadifar, Zahra

2014-03-01

Sulfur oxides released from the burning of oil causes severe environmental pollution. The sulfur can be removed via the 4S pathway in biodesulfurization (BDS). Immobilization approaches have been developed to prevent cell contamination of oil during the BDS process. The encapsulation of Rhodococcus erythropolis R1 in calcium alginate beads was studied in order to enhance conversion of dibenzothiophene (DBT) to 2-hydroxy biphenyl (2-HBP) as the final product. Also the effect of different factors on the BDS process was investigated. Calcium alginate capsules were prepared using peristaltic pumps with different needle sizes to control the beads sizes. Scanning electron microscopy and flow cytometry methods were used to study the distribution and viability of encapsulated cells, respectively. Two non-ionic surfactants and also nano Ƴ-Al2O3were used with the ratio of 0.5% (v/v) and 1:5 (v/v) respectively to investigate their BDS efficiency. In addition, the effect of different bead sizes and different concentrations of sodium alginate in BDS activity was studied. The 2% (w/v) sodium alginate beads with 1.5mm size were found to be the optimum for beads stability and efficient 2-HBP production. The viability of encapsulated cells decreased by 12% after 20 h of desulfurization, compared to free cells. Adding the non-ionic surfactants markedly enhanced the rate of BDS, because of increasing mass transfer of DBT to the gel matrix. In addition, Span 80 was more effective than Tween 80. The nanoƳ-Al2O3 particles could increase BDS rate by up to two-folds greater than that of the control beads. The nano Ƴ-Al2O3 can improve the immobilized biocatalyst for excellent efficiency of DBT desulfurization. Also the BDS activity can be enhanced by setting the other explained factors at optimum levels.

A Highly Conserved Leucine in Mammarenavirus Matrix Z Protein Is Required for Z Interaction with the Virus L Polymerase and Z Stability in Cells Harboring an Active Viral Ribonucleoprotein.

PubMed

Iwasaki, Masaharu; de la Torre, Juan C

2018-06-01

Mammarenaviruses cause chronic infections in their natural rodent hosts. Infected rodents shed infectious virus into excreta. Humans are infected through mucosal exposure to aerosols or direct contact of abraded skin with fomites, resulting in a wide range of manifestations from asymptomatic or mild febrile illness to severe life-threatening hemorrhagic fever. The mammarenavirus matrix Z protein has been shown to be a main driving force of virus budding and to act as a negative regulator of viral RNA synthesis. To gain a better understanding of how the Z protein exerts its several different functions, we investigated the interaction between Z and viral polymerase L protein using the prototypic mammarenavirus, lymphocytic choriomeningitis virus (LCMV). We found that in the presence of an active viral ribonucleoprotein (vRNP), the Z protein translocated from nonionic detergent-resistant, membrane-rich structures to a subcellular compartment with a different membrane composition susceptible to disruption by nonionic detergents. Alanine (A) substitution of a highly conserved leucine (L) at position 72 in LCMV Z protein abrogated Z-L interaction. The L72A mutation did not affect the stability or budding activity of Z when expressed alone, but in the presence of an active vRNP, mutation L72A promoted rapid degradation of Z via a proteasome- and lysosome-independent pathway. Accordingly, L72A mutation in the Z protein resulted in nonviable LCMV. Our findings have uncovered novel aspects of the dynamics of the Z protein for which a highly conserved L residue was strictly required. IMPORTANCE Several mammarenaviruses, chiefly Lassa virus (LASV), cause hemorrhagic fever disease in humans and pose important public health concerns in their regions of endemicity. Moreover, mounting evidence indicates that the worldwide-distributed, prototypic mammarenavirus, lymphocytic choriomeningitis virus (LCMV), is a neglected human pathogen of clinical significance. The mammarenavirus matrix Z protein plays critical roles in different steps of the viral life cycle by interacting with viral and host cellular components. Here we report that alanine substitution of a highly conserved leucine residue, located at position 72 in LCMV Z protein, abrogated Z-L interaction. The L72A mutation did not affect Z budding activity but promoted its rapid degradation in the presence of an active viral ribonucleoprotein (vRNP). Our findings have uncovered novel aspects of the dynamics of the Z protein for which a highly conserved L residue was strictly required. Copyright © 2018 American Society for Microbiology.

A novel paclitaxel-loaded poly(d,l-lactide-co-glycolide)-Tween 80 copolymer nanoparticle overcoming multidrug resistance for lung cancer treatment

PubMed Central

Yuan, Xun; Ji, Wenxiang; Chen, Si; Bao, Yuling; Tan, Songwei; Lu, Shun; Wu, Kongming; Chu, Qian

2016-01-01

Drug resistance has become a main obstacle for the effective treatment of lung cancer. To address this problem, a novel biocompatible nanoscale package, poly(d,l-lactide-co-glycolide)-Tween 80, was designed and synthesized to overcome paclitaxel (PTX) resistance in a PTX-resistant human lung cancer cell line. The poly(d,l-lactide-co-glycolide) (PLGA)-Tween 80 nanoparticles (NPs) could efficiently load PTX and release the drug gradually. There was an increased level of uptake of PLGA-Tween 80 in PTX-resistant lung cancer cell line A549/T, which achieved a significantly higher level of cytotoxicity than both PLGA NP formulation and Taxol®. The in vivo antitumor efficacy also showed that PLGA-Tween 80 NP was more effective than Taxol®, indicating that PLGA-Tween 80 copolymer was a promising carrier for PTX in resistant lung cancer. PMID:27307727

Tween 80 effect on glucosyltransferase synthesis by Streptococcus salivarius.

PubMed Central

Wittenberger, C L; Beaman, A J; Lee, L N

1978-01-01

Streptococcus salivarius (ATCC 25975) produced very low or nondetectable amounts of the extracellular enzyme glucosyltransferase (GTase) when grown in a chemically defined medium. The addition of Tween 80 to this medium resulted in the production of markedly enhanced levels of the enzyme. Oleic acid, the methyl ester of oleic acid, and sucrose each could not substitute for Tween 80 in this regard. The surfactant had no direct activating effect on performed enzyme activity. Tween 80 also stimulated the production of GTase by concentrated cells suspended in defined medium during a time when no measurable growth occurred. Under these conditions, the stimulatory effect of Tween 80 was blocked by chloramphenicol. It was further found that the surfactant dramatically stimulated the differential rate of GTase synthesis. These and other data strongly suggest that Tween 80 stimulates the production of extracellular GTase by acting either directly or indirectly at the level of enzyme synthesis. PMID:618839

Refolding of SDS-Unfolded Proteins by Nonionic Surfactants.

PubMed

Kaspersen, Jørn Døvling; Søndergaard, Anne; Madsen, Daniel Jhaf; Otzen, Daniel E; Pedersen, Jan Skov

2017-04-25

The strong and usually denaturing interaction between anionic surfactants (AS) and proteins/enzymes has both benefits and drawbacks: for example, it is put to good use in electrophoretic mass determinations but limits enzyme efficiency in detergent formulations. Therefore, studies of the interactions between proteins and AS as well as nonionic surfactants (NIS) are of both basic and applied relevance. The AS sodium dodecyl sulfate (SDS) denatures and unfolds globular proteins under most conditions. In contrast, NIS such as octaethylene glycol monododecyl ether (C 12 E 8 ) and dodecyl maltoside (DDM) protect bovine serum albumin (BSA) from unfolding in SDS. Membrane proteins denatured in SDS can also be refolded by addition of NIS. Here, we investigate whether globular proteins unfolded by SDS can be refolded upon addition of C 12 E 8 and DDM. Four proteins, BSA, α-lactalbumin (αLA), lysozyme, and β-lactoglobulin (βLG), were studied by small-angle x-ray scattering and both near- and far-UV circular dichroism. All proteins and their complexes with SDS were attempted to be refolded by the addition of C 12 E 8 , while DDM was additionally added to SDS-denatured αLA and βLG. Except for αLA, the proteins did not interact with NIS alone. For all proteins, the addition of NIS to the protein-SDS samples resulted in extraction of the SDS from the protein-SDS complexes and refolding of βLG, BSA, and lysozyme, while αLA changed to its NIS-bound state instead of the native state. We conclude that NIS competes with globular proteins for association with SDS, making it possible to release and refold SDS-denatured proteins by adding sufficient amounts of NIS, unless the protein also interacts with NIS alone. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Influencing the parents of children aged 9-13 years: findings from the VERB campaign.

PubMed

Price, Simani M; Huhman, Marian; Potter, Lance D

2008-06-01

The CDC's VERB campaign was designed to increase physical activity among children aged 9-13 years (tweens). As part of the strategy to surround tweens with support to be physically active, VERB developed messages for parents, the secondary target audience, to encourage them to support their tween's physical activity. Multiple regression analyses were conducted to determine whether parent awareness of VERB was a significant predictor of seven factors that related to parental attitudes, beliefs, and supportive behaviors for tweens' physical activity using the Youth Media Campaign Longitudinal Survey (YMCLS). Parents (N=1946) of U.S. children aged 9-13 years. Advertising directed at tweens through paid television, radio, print, Internet, and schools was the primary VERB intervention; tween advertising could have been also seen by parents. Messages directed at parents encouraging their support of tweens' physical activity were delivered in English through mainly print and radio. In-language messages for Latino and Asian audiences were delivered through print, radio, television, and at events. Parents' awareness of VERB; parents' attitudes, beliefs, and support for their tweens' physical activities. Awareness increased each year of the campaign; more than 50% of parents were aware of VERB by the third year of the campaign. Parents reported that their main source of awareness was television, the main channel used to reach tweens. Awareness of VERB was predictive of positive attitudes about physical activity for all children, belief in the importance of physical activity for their own child, and the number of days parents were physically active with their child. Parents' awareness of VERB was associated with positive attitudes, beliefs, and behavior. Parents' awareness probably resulted from a combination of messages directed to parents and tweens. To maximize audience reach, social marketers who are developing health messages should consider the potential value of parents and their children seeing or hearing the same messages, separately or together.

Influence of Polysorbate 60 on Formulation Properties and Bioavailability of Morin-Loaded Nanoemulsions with and without Low-Saponification-Degree Polyvinyl Alcohol.

PubMed

Ikeuchi-Takahashi, Yuri; Kobayashi, Ayaka; Ishihara, Chizuko; Matsubara, Takumi; Matsubara, Hiroaki; Onishi, Hiraku

2018-01-01

The aim of the present study was to investigate the influence of polysorbate 60 (Tween 60) on the development of morin-loaded nanoemulsions to improve the oral bioavailability of morin. Nanoemulsions were prepared using Tween 60 and polyvinyl alcohol (PVA) as emulsifiers, and medium chain triglycerides (MCT) as the lipid base. Low-saponification-degree PVA (LL-810) was also added to stabilize dispersed droplets. MCT-LL810 nanoemulsion containing LL-810 was prepared with a reduced amount of Tween 60. However, the area under the blood concentration-time curve (AUC) of MCT-LL810 (0.18) nanoemulsion containing a small amount of Tween 60 did not increase because the absorption of morin was limited by P-glycoprotein (P-gp)-mediated efflux. MCT-LL810 (0.24) nanoemulsion containing a large amount of Tween 60 showed the highest AUC, dispersed droplets containing Tween 60 may have been transported into epithelial cells in the small intestine, and P-gp transport activity appeared to be suppressed by permeated Tween 60. Based on the plasma concentration profile, dispersed droplets in MCT-LL810 (0.24) nanoemulsion permeated more rapidly through the mucus layer and the intestinal membrane than MCT (0.24) nanoemulsion without LL-810. In conclusion, a novel feature of Tween 60 incorporated into the dispersed droplets of a nanoemulsion interacting with P-gp was demonstrated herein. Dispersed droplets in MCT-LL810 (0.24) nanoemulsion containing LL-810 permeated rapidly through the mucus layer and intestinal membrane, and Tween 60 incorporated in dispersed droplets interacted with P-gp-mediated efflux, increasing the bioavailability of morin.

Inhibition of vincristine binding to plasma membrane vesicles from daunorubicin-resistant Ehrlich ascites cells by multidrug resistance modulators.

PubMed Central

Sehested, M.; Jensen, P. B.; Skovsgaard, T.; Bindslev, N.; Demant, E. J.; Friche, E.; Vindeløv, L.

1989-01-01

The multidrug resistance (MDR) phenotype is presumed to be mostly dependent on changes in the resistant cell plasma membrane, notably the emergence of a 170 kDa glycoprotein called P-glycoprotein, which facilitate increased drug efflux. We have previously demonstrated that ATP-enhanced binding of vincristine (VCR) to plasma membrane vesicles is much greater in MDR than in wild type cells. The present study has shown that VCR binding to MDR Ehrlich ascites tumour cell plasma membrane vesicles is inhibited 50% most efficiently by quinidine (0.5 microM) followed by verapamil (4.1 microM) and trifluoperazine (23.2 microM). This is the reverse order of the effect on whole cells where a ranking of efficiency in terms of enhancement of VCR accumulation, inhibition of VCR efflux, DNA perturbation and modulation of resistance in a clonogenic assay, was trifluoperazine greater than or equal to verapamil much greater than quinidine. The detergent Tween 80 inhibited VCR binding to plasma membrane vesicles at 0.001% v/v which agreed with the level which modulated resistance and increased VCR accumulation in whole cells. No effect was observed on daunorubicin binding to MDR plasma membrane vesicles after incubation with either Tween 80 (up to 0.1% v/v) or verapamil (up to 25 microM). We conclude that the effect of a modulating drug in reversing resistance to VCR correlates with its ability to raise intracellular VCR levels but not with its capability to inhibit VCR binding to the plasma membrane. Thus, enhancement of VCR accumulation in MDR cells is hardly solely due to competition for a drug binding site on P-glycoprotein. Furthermore, the lack of a demonstrable effect on daunorubicin binding to the plasma membrane by modulators points to transport mechanisms which do not utilise specific drug binding to the plasma membrane. PMID:2605092

Tweens' Characterization of Digital Technologies

ERIC Educational Resources Information Center

Brito, Pedro Quelhas

2012-01-01

The tweens are a transitional age group undergoing deep physical and psychological transformations. Based on a thirteen-focus group research design involving 103 students, and applying a tweens-centered approach, the characteristics of SMS, IM, Internet, digital photos, electronic games, and email were analyzed. Categories such as moral issues,…

Tween Consumers: Catalog Clothing Purchase Behavior.

ERIC Educational Resources Information Center

Simpson, Linda; Douglas, Sara; Schimmel, Julie

1998-01-01

Catalog shopping behavior of younger and older adolescents was compared. Results indicated that "tweens" were more concerned with style, brand name, and fashion than were older students. This supports previous findings indicating that the tween years are a time when peer pressure and "fitting in" are very important. (Author/EMK)

Role of Glycols and Tweens in the Production of Ergot Alkaloids by Claviceps paspali

PubMed Central

Mizrahi, A.; Miller, G.

1969-01-01

Several glycols and Tweens markedly stimulated the production of ergot alkaloids in submerged cultures of Claviceps paspali. The role of these compounds was investigated in shake flasks and bench-scale fermentors. 2,3-Butanediol was not utilized by the fungus, and 1,2-propanediol-1-14C was not incorporated into the alkaloids. Glycols and Tweens lowered the surface tension of the basal medium and promoted the utilization of metabolites. In the presence of glycols and Tweens, an increased uptake of labeled sorbitol and succinic acid took place, whereas the specific radioactivity of the alkaloids was not affected. These results indicated that glycols and Tweens are not involved directly in the biosynthetic process; they apparently acted as surface-active agents, facilitating transport of metabolites into the cells. PMID:5776521

Comparative transcriptomic evidence for Tween80-enhanced biodegradation of phenanthrene by Sphingomonas sp. GY2B.

PubMed

Liu, Shasha; Guo, Chuling; Lin, Weijia; Wu, Fengji; Lu, Guining; Lu, Jing; Dang, Zhi

2017-12-31

Previous study of the effects of surfactants on the biodegradation of phenanthrene focused on investigating alterations of the cell characteristics of Sphingomonas sp. GY2B. However, genes regulation associated with biodegradation and biological processes in response to the presence of surfactants, remains unclear. In this study, comparative transcriptome analysis was conducted to observe the gene expression of GY2B during phenanthrene biodegradation in the presence and absence of Tween80. A diverse set of genes was regulated by Tween80, leading to increased biodegradation of phenanthrene by GY2B: (i) Tween80 increased expression of genes related to H + transport in the plasma membrane to provide a driving force (i.e., ATP) for accelerating transmembrane transport of phenanthrene with increasing Tween80 concentrations, thereby enhancing the uptake and degradation of phenanthrene by GY2B; (ii) Tween80 (1 and 8 CMC) promoted intracellular biodegradation of phenanthrene by stimulating expression of genes encoding dioxygenases and monooxygenase, increasing expression of genes involved in intracellular metabolic processes (e.g., TCA cycle); and (iii) Tween80 likely increased GY2B vitality and growth by inducing expression of genes associated with ABC transporters and protein transport, regulating genes involved in other biological processes (e.g., transcription, translation). Copyright © 2017. Published by Elsevier B.V.

Size is a major determinant of dissociation and denaturation behaviour of reconstituted high-density lipoproteins.

PubMed Central

Gianazza, Elisabetta; Eberini, Ivano; Sirtori, Cesare R; Franceschini, Guido; Calabresi, Laura

2002-01-01

Lipid-free apolipoprotein A-I (apoA-I) and A-I(Milano) (A-I(M)) were compared for their denaturation behaviour by running across transverse gradients of a chaotrope, urea, and of a ionic detergent, SDS. For both apo A-I and monomeric apoA-I(M) in the presence of increasing concentrations of urea the transition from high to low mobility had a sigmoidal course, whereas for dimeric A-I(M)/A-I(M) a non-sigmoidal shape was observed. The co-operativity of the unfolding process was lower for dimeric A-I(M)/A-I(M) than for apoA-I or for monomeric apoA-I(M). A slightly higher susceptibility to denaturation was observed for dimeric A-I(M)/A-I(M) than for monomeric apoA-I(M). A similar behaviour of A-I(M)/A-IM versus apoA-I(M) was observed in CD experiments. Large- (12.7/12.5 nm) and small- (7.8 nm) sized reconstituted high-density lipoproteins (rHDL) containing either apoA-I or A-I(M)/A-I(M) were compared with respect to their protein-lipid dissociation behaviour by subjecting them to electrophoresis in the presence of urea, of SDS and of a non-ionic detergent, Nonidet P40. A higher susceptibility to dissociation of small-sized versus large-sized rHDL, regardless of the apolipoprotein component, was observed in all three instances. Our data demonstrate that the differential plasticity of the various classes of rHDL is a function of their size; the higher stability of 12.5/12.7 nm rHDL is likely connected to the higher number of protein-lipid and lipid-lipid interactions in larger as compared with smaller rHDL. PMID:11996671

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

Enzymatic hydrolysis of sodium dodecyl sulphate (SDS)-pretreated newspaper for cellulosic ethanol production by Saccharomyces cerevisiae and Pichia stipitis.

PubMed

Xin, Fengxue; Geng, Anli; Chen, Ming Li; Gum, Ming Jun Marcus

2010-10-01

Fermentation of enzymatic hydrolysate of waste newspaper was investigated for cellulosic ethanol production in this study. Various nonionic and ionic surfactants were applied for waste newspaper pretreatment to increase the enzymatic digestibility. The surfactant-pretreated newspaper was enzymatically digested in 0.05 M sodium citrate buffer (pH 4.8) with varying solid content, filter paper unit loading (FPU/g newspaper), and ratio of filter paper unit/beta-glucosidase unit (FPU/CBU). Newspaper pretreated with the anionic surfactant sodium dodecyl sulphate (SDS) demonstrated the highest sugar yield. The addition of Tween-80 in the enzymatic hydrolysis process enhanced the enzymatic digestibility of newspaper pretreated with all of the surfactants. Enzymatic hydrolysis of SDS-pretreated newspaper with 15% solid content, 15 FPU/g newspaper, and FPU/CBU of 1:4 resulted in a newspaper hydrolysate conditioning 29.07 g/L glucose and 4.08 g/L xylose after 72 h of incubation at 50 degrees C. The fermentation of the enzymatic hydrolysate with Saccharomyces cerevisiae, Pichia stipitis, and their co-culture produced 14.29, 13.45, and 14.03 g/L of ethanol, respectively. Their corresponding ethanol yields were 0.43, 0.41, and 0.42 g/g.

Retention and release of oil-in-water emulsions from filled hydrogel beads composed of calcium alginate: impact of emulsifier type and pH.

PubMed

Zeeb, Benjamin; Saberi, Amir Hossein; Weiss, Jochen; McClements, David Julian

2015-03-21

Delivery systems based on filled hydrogel particles (microgels) can be fabricated from natural food-grade lipids and biopolymers. The potential for controlling release characteristics by modulating the electrostatic interactions between emulsifier-coated lipid droplets and the biopolymer matrix within hydrogel particles was investigated. A multistage procedure was used to fabricate calcium alginate beads filled with lipid droplets stabilized by non-ionic, cationic, anionic, or zwitterionic emulsifiers. Oil-in-water emulsions stabilized by Tween 60, DTAB, SDS, or whey protein were prepared by microfluidization, mixed with various alginate solutions, and then microgels were formed by simple extrusion into calcium solutions. The microgels were placed into a series of buffer solutions with different pH values (2 to 11). Lipid droplets remained encapsulated under acidic and neutral conditions, but were released under highly basic conditions (pH 11) due to hydrogel swelling when the alginate concentration was sufficiently high. Lipid droplet release increased with decreasing alginate concentration, which could be attributed to an increase in the pore size of the hydrogel matrix. These results have important implications for the design of delivery systems to entrap and control the release of lipophilic bioactive components within filled hydrogel particles.

Technology of stable, prolonged-release eye-drops containing Cyclosporine A, distributed between lipid matrix and surface of the solid lipid microspheres (SLM).

PubMed

Wolska, Eliza; Sznitowska, Małgorzata

2013-01-30

The aim of this study was to prepare solid lipid microspheres (SLM) with incorporated Cyclosporine A (Cs), suitable for ocular application. For this purpose, SLM were formulated by using different lipids and three different nonionic surfactants. The SLM were produced using a hot emulsification method. The SLM dispersions contained 10, 20 or 30% of lipid (w/w) and up to 2% (w/w) of Cs. The size of the microspheres with Cs ranged from 1 to 15 μm. Physically stable SLM with Cs were prepared using Compritol, as a lipid matrix, and Tween 80, as a surfactant. In contrast, dispersion with Precirol alone, formed semi-solid gels during storage, while in formulations with Precirol and Miglyol, crystals of Cs were observed. In vitro release profile of Compritol formulations showed that 40% of Cs is released within 1h, while the release of the following 40% takes more time, depending on lipid content in the formulations. The large part of Cs, added to SLM formulations (from 45 to 80%), was found on the surface of microparticles, but no drug crystallization occurred during a long-term storage. Copyright © 2012 Elsevier B.V. All rights reserved.

Design and development of aqueous nanoformulations for mosquito control.

PubMed

Montefuscoli, Antonela Rita; Werdin González, Jorge Omar; Palma, Santiago Daniel; Ferrero, Adriana Alicia; Fernández Band, Beatriz

2014-02-01

Microemulsions (ME) are thermodynamically stable isotropic mixtures of oil, water, and surfactant; they would also be attractive as potential insecticidal products due to the high bioviability of the active ingredient, attributable to the small sizes of the oil drops. A laboratory study was conducted in order to compare the biological effect of oil in water (o/w) geranium essential oil (EO) and geraniol MEs and emulsions, against Culex pipiens pipiens mosquito larvae. The systems were based on three nonionic surfactants (Cremophor EL, Brij 35, Tween 80). The MEs showed dispersed phase diameters in the range of 8 to 14 nm and had low PDI values (<0.2). The MEs were analyzed by TEM, indicating that they had nearly spherical morphology. The microemulsified systems based on geranium EO and those of geraniol produced a notable increase of the larvicidal activity when compared with the respectably emulsions, concluding that the biological effect is related with the diameter of the dispersed phase. The smallest drops achieved the highest larvicidal activity, being the aqueous nanoformulations based on geraniol most effective than those of geranium EO. However, geranium microemulsions are preferred due to their residual toxicological profiles. The results indicate that these novel systems could be used in integrated pest management program for the C. pipiens pipiens.

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

Bulk and dispersed aqueous behaviour of an endogenous lipid, selachyl alcohol: Effect of Tween 80 and Pluronic F127 on nanostructure.

PubMed

Younus, Mohammad; Hawley, Adrian; Boyd, Ben J; Rizwan, Shakila B

2018-05-07

Tween 80 has been reported to provide a means of targeting drug nanocarriers to the blood- brain barrier. This study investigated the influence of addition of Tween 80 on the formation of different bulk and dispersed lyotropic liquid crystalline phases in selachyl alcohol-based systems. The effect of increasing concentrations of Tween 80 and Pluronic F127 (as a control) (0-25% w/w relative to SA) on the bulk phase behaviour and dispersions of selachyl alcohol (SA) were investigated using small angle X-ray scattering, dynamic light scattering, and cryogenic transmission electron microscopy. The addition of Tween 80 to SA bulk phase samples triggered concentration-dependent phase changes with the structure sequentially evolving from a reverse hexagonal phase (H 2 ) to a mixed H 2 and inverse bicontinuous cubic (V 2 ) then a V 2 phase alone. In contrast, the addition of Pluronic F127 resulted in a phase change from H 2 phase to a mixed lamellar and H 2 phase system. The mean particle size of internally structured particles was 125-190 nm with low polydispersity indices (0.1-0.2). Nanoparticles retained the bulk phase internal structure in the presence of Tween 80, whereas in the presence of Pluronic F127, the additional lamellar phase that formed in bulk phase systems was not observed. Cryo-TEM revealed the formation of cubosomes and hexosomes by SA in excess water in the presence of Tween 80 and Pluronic F127 respectively. In summary, it was shown that stabilisation of SA dispersions using Tween 80 resulted in a decrease in negative curvature leading to a change in internal structure from H 2 to V 2 phase. The studies provide the core understanding of particle structure to progress these structured lipid nanocarriers into delivery studies with Tween 80 as a mechanism to target the blood-brain barrier. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Adsorption of Anionic, Cationic and Nonionic Surfactants on Carbonate Rock in Presence of ZrO 2 Nanoparticles

NASA Astrophysics Data System (ADS)

Esmaeilzadeh, Pouriya; Bahramian, Alireza; Fakhroueian, Zahra

The adsorption of surfactants at the solid-water interface is important for the control of wetting, lubrication, detergency and in mineral flotation.We have studied the adsorptions of different types of surfactants, cationic (Dodecyl trimethylammonium bromide, DTAB), anionic (sodium dodecyl sulfate, SDS) and non-anionic (lauryl alcohol-7 mole ethoxylate, LA7) on carbonate rock in presence of zirconium oxide spherical nanoparticles (17-19 nm). ZrO2 nanoparticles with tetrahedral structure have significant effect on adsorption of surfactants on the carbonate rock. We have used the measured conductivities to determine the rate of adsorption of surfactants at rock-water interfaces. The conductivity of DTAB in aqueous solutions containing calcite powder decreases more than the other surfactants in contact with ZrO2 nanoparticles. We have also investigated the adsorption of surfactants at the air-water interface. The presence of nanoparticles, as demonstrated by our experiments, enhances the surface activity and surface adsorption of the surfactants through electrostatic forces or formation of nanostructures. Dynamic light structuring data shows similar aggregation number of nanoparticles in presence of nanoparticles.

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.

A simple and rapid method for the reversible removal of lipids from a membrane-bound enzyme.

PubMed Central

Goodman, S L; Isern de Caldentey, M; Wheeler, K P

1978-01-01

A simple, rapid and reproducible method for the reversible removal of lipids from a membrane-bound enzyme is described. Essentially, a membrane preparation containing (Na+ + K+)-dependent adenosine triphosphatase was extracted with the non-ionic detergent Lubrol WX in the presence of glycerol, and partial separation of protein from lipid was achieved with the use of only two centrifugations. About 74% of the endogenous phospholipid and 79% of the cholesterol were removed, concomitant with a virtually complete loss of ouabain-sensitive adenosine triphosphatase activity, but with retention of 60-100% of the K+-dependent phosphatase activity. The addition of pure phosphatidylserine re-activated the enzyme to more than 80% of the initial activity, and up to 30% of the protein was recovered. Excess of phosphatidylserine could be washed off the enzyme to give a stable 'reconstituted' preparation. The effects of variation in the experimental conditions were examined, and the results are discussed with respect to the possibility of adapting the method to the study of other lipid-dependent enzymes bound to membranes. PMID:147078

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

Purification and biochemical characterization of a cold-active lipase from Antarctic sea ice bacteria Pseudoalteromonas sp. NJ 70.

PubMed

Wang, Quanfu; Hou, Yanhua; Ding, Yu; Yan, Peisheng

2012-09-01

An extracellular cold-active lipase from Antarctic sea ice bacteria Pseudoalteromonas sp. NJ 70 was purified and characterized. The overall purification based on lipase activity was 27.5-fold with a yield of 25.4 %. The purified lipase showed as a single band on SDS-PAGE with an apparent molecular weight of 37 kDa. The optimum temperature and pH were 35 °C and 7.0, respectively. The lipase activity was enhanced by Ca(2+) and Mg(2+), while was partially inhibited by other metals such as Cu(2+), Zn(2+), Ba(2+), Pb(2+), Fe(2+) and Mn(2+). The lipase had high tolerance to a wide range of NaCl concentrations (0-2 M NaCl). It exhibited high levels of activity in the presence of DTT, Thiourea, H(2)O(2) as well as in the presence of various detergents such as Span 60, Tween-80, Triton X-100. In addition, the lipase showed a preference for long-chain p-nitrophenyl esters (C(12)-C(18)). These results indicated that this lipase could be a novel cold-active lipase.

Bactericidal effect of the 908 nm diode laser on Enterococcus faecalis in infected root canals

PubMed Central

Preethee, Thomas; Kandaswamy, Deivanayagam; Arathi, Ganesh; Hannah, Rosaline

2012-01-01

Aim: The aim of this study is to evaluate the bactericidal effect of 908 nm diode laser in conjunction with various irrigation regimes in disinfection of apical third of root dentin. Materials and Methods: Sixty prepared teeth with single canals were contaminated with Enterococcus faecalis. The specimens were divided into 6 groups (n = 10): Group 1 and 3 and 5 were subjected to chemo-mechanical preparation using 5.25% sodium hypochlorite (NaOCl), 17% Ethylenediaminetetraacetic acid (EDTA); 1.3% NaOCl, MTAD (mixture of doxycycline, citric acid and a detergent (Tween 80); and, 8.5% saline, respectively followed by 908 nm diode laser irradiation; Group 2 and 4, followed the same procedure as Group1 and 3, however without laser irradiation; and, Group 6, rinsed with saline solution (control). Dentin shavings from apical third were analyzed for the presence of E. faecalis using culture method and Polymerase Chain reaction (PCR). Results: One-way Analysis of variance showed statistically significant differences between the laser irradiated groups, non irradiated groups and the control group. Conclusion: 908 nm diode used in conjunction with conventional chemomechanical techniques demonstrated a significant elimination of E. faecalis in the apical third of root dentin. PMID:22368335

Purification and characterization of novel extracellular cholesterol esterase from Acinetobacter sp.

PubMed

Du, Liangjun; Huo, Ying; Ge, Fanglan; Yu, Jiajun; Li, Wei; Cheng, Guiying; Yong, Bin; Zeng, Lihuang; Huang, Min

2010-12-01

CHE4-1, a bacterial strain that belongs to the genus Acinetobacter and expresses high level of inducible extracellular cholesterol esterase (CHE), was isolated from feces of carnivore Panthera pardus var. The cholesterol esterase of the strain CHE4-1 was purified by ultrafiltration followed with DEAE-Sepharose FF chromatography and Phenyl-Sepharose CL-4B chromatography, and then by Sephadex G-50 gel filtration. Different from other known microbial cholesterol esterase, the purified CHE from CHE4-1 strain is a monomer with molecular weight of 6.5 kD and has high activity to both long-chain and short-chain cholesterol ester. Enzymatic activity was enhanced in the presence of metal ion Ca(2+), Zn(2+) and boracic acid, and was not significantly affected by several detergents including sodium cholate, Triton X100 and Tween-80. The enzyme was found to be stable during long-term aqueous storage at 4 °C, indicating its potential as a clinical diagnostic reagent. To the best of our knowledge, this is the first report regarding purification and characterization of CHE from Acinetobacter sp. The results demonstrated that this particular CHE is a novel cholesterol esterase.

In vitro digestibility of normal and waxy corn starch is modified by the addition of Tween 80.

PubMed

Vernon-Carter, E J; Alvarez-Ramirez, J; Bello-Perez, L A; Garcia-Hernandez, A; Roldan-Cruz, C; Garcia-Diaz, S

2018-05-15

Aqueous dispersions of normal and waxy corn starch (3% w/w) were mixed with Tween 80 (0, 7.5, 15, 22.5 and 30 g/100 g of starch), and gelatinized (90 °C, 20 min). Optical microscopy of the gelatinized starch dispersions (GSD x ; x = Tween 80 concentration) revealed that the microstructure was characterized by a continuous phase of leached amylose and amylopectin entangled chains, and a dispersed phase of insoluble remnants, called ghosts, on whose surface small granules were observed, imputed to Tween 80. The apparent viscosity of the GSD x decreased as the concentration of Tween 80 increased (up to about 70-90%). FTIR analysis of dried GSD x indicated that Tween 80 addition decreased short-range ordering. The content of rapidly digestible starch (RDS) and resistant starch (RS) fractions tended to increase significantly, at the expense of a significant decrease of slowly digestible starch (SDS) fraction, an effect that may be attributed to the increase of amorphous structures and starch chain-surfactant complexes. The RDS and RS increase was more pronounced for normal than for waxy corn starch, and the significance of the increase was dependent on Tween 80 concentration. Overall, the results showed that surfactant can affect largely the digestibility of starch chains. Copyright © 2018 Elsevier B.V. All rights reserved.

Maintenance of Dimer Conformation by the Dengue Virus Core Protein α4-α4′ Helix Pair Is Critical for Nucleocapsid Formation and Virus Production

PubMed Central

Teoh, Pak-Guan; Huang, Zhi-Shun; Pong, Wen-Li; Chen, Po-Chiang

2014-01-01

ABSTRACT The virion of dengue virus (DENV) is composed of a viral envelope covering a nucleocapsid formed by a complex of viral genomic RNA and core protein (CP). DENV CP forms a dimer via the internal α2 and α4 helices of each monomer. Pairing of α2-α2′ creates a continuous hydrophobic surface, while the α4-α4′ helix pair joins the homodimer via side-chain interactions of the inner-edge residues. However, the importance of dimer conformation and the α4 helix of DENV CP in relation to its function are poorly understood. Loss of association between CP and lipid droplets (LDs) due to mutation suggests that the CP hydrophobic surface was not exposed, offering a possible explanation for the absence of dimers. Further assays suggest the connection between CP folding and protein stability. Attenuation of full-length RNA-derived virus production is associated with CP mutation, since no significant defects were detected in virus translation and replication. The in vitro characterization assays further highlighted that the α4-α4′ helix pair conformation is critical in preserving the overall α-helical content, thermostability, and dimer formation ability of CP, features correlated with the efficiency of nucleocapsid formation. Addition of Tween 20 improves in vitro nucleocapsid-like particle formation, suggesting the role of the LD in nucleocapsid formation in vivo. This study provides the first direct link between the α4-α4′ helix pair interaction and the CP dimer conformation that is the basis of CP function, particularly in nucleocapsid formation during virion production. IMPORTANCE Structure-based mutagenesis study of the dengue virus core protein (CP) reveals that the α4-α4′ helix pair is the key to maintaining its dimer conformation, which is the basis of CP function in nucleocapsid formation and virus production. Attenuation of full-length RNA-derived virus production is associated with CP mutation, since no significant defects in virus translation and replication were detected. In vitro inefficiency and size of nucleocapsid-like particle (NLP) formation offer a possible explanation for in vivo virus production inefficiency upon CP mutation. Further, the transition of NLP morphology from an incomplete state to an intact particle shown by α4-α4′ helix pair mutants in the presence of a nonionic detergent suggests the regulatory role of the intracellular lipid droplet (LD) in CP-LD interaction and in promoting nucleocapsid formation. This study provides the first direct link between the α4-α4′ helix pair interaction and CP dimer conformation that is the fundamental requirement of CP function, particularly in nucleocapsid formation during virion production. PMID:24807709

Design and ocular tolerance of flurbiprofen loaded ultrasound-engineered NLC.

PubMed

Gonzalez-Mira, E; Egea, M A; Garcia, M L; Souto, E B

2010-12-01

Packaging small drug molecules, such as non-steroidal anti-inflammatory drugs (NSAIDs) into nanoparticulate systems has been reported as a promising approach to improve the drug's bioavailability, biocompatibility and safety profiles. In the last 20 years, lipid nanoparticles (lipid dispersions) entered the nanoparticulate library as novel carrier systems due to their great potential as an alternative to other systems such as polymeric nanoparticles and liposomes for several administration routes. For ocular instillation nanoparticulate carriers are required to have a low mean particle size, with the lowest polydispersity as possible. The purpose of this work was to study the combined influence of 2-level, 4-factor variables on the formulation of flurbiprofen (FB), a lipophilic NSAID, in lipid carriers currently named as nanostructured lipid carriers (NLC). NLC were produced with stearic acid (SA) and castor oil (CO) stabilized by Tween® 80 (non-ionic surfactant) in aqueous dispersion. A 2(4) full factorial design based on 4 independent variables was used to plan the experiments, namely, the percentage of SA with regard to the total lipid, the FB concentration, the stabilizer concentration, and the storage conditions (i.e., storage temperature). The effects of these parameters on the mean particle size, polydispersity index (PI) and zeta potential (ZP) were investigated as dependent variables. The optimization process was achieved and the best formulation corresponded to the NLC formulation composed of 0.05 (wt%) FB, 1.6 (wt%) Tween® 80 and a 50:50 ratio of SA to CO, with an average diameter of 288 nm, PI 0.245 of and ZP of -29 mV. This factorial design study has proven to be a useful tool in optimizing FB-loaded NLC formulations. Stability of the optimized NLC was predicted using a TurbiScanLab® and the ocular tolerance was assessed in vitro and in vivo by the Eytex® and Draize test, respectively. The developed systems were shown physico-chemically stable with high tolerance for eye instillation. Copyright © 2010 Elsevier B.V. All rights reserved.

Technological Evaluation of Emulsions Containing The Volatile Oil from Leaves of Plectranthus Amboinicus Lour

PubMed Central

Lopes, Pablo Queiroz; Carneiro, Fabíola Bernardo; de Sousa, Ana Letícia Braz; Santos, Sócrates Golziodo; Oliveira, Elquio Eleamen; Soares, Luiz Alberto Lira

2017-01-01

Background: Plectranthus amboinicus Lour is a species which is widespread throughout tropical countries where it is widely used against respiratory tract disorders such as bronchodilator, antitussive, and expectorant conditions. Objective: This study aims to characterize the essential oil of P. amboinicus (PaEO) and produce and evaluate emulsions containing PaEO. Materials and Methods: The essential oil was characterized by physical-chemical analyses for density, refractive index, 90% ethanol solubility, color, appearance, and identification by gas chromatography coupled to mass spectrometry detection. The emulsions were prepared following a hydrophile-lipophile balance [HLB] spreadsheet design from two nonionic surfactants (Span 80® and Tween 20®) producing HLB values ranging from 4.3 to 16.7. The products were stored at room temperature at 5°C. The emulsion stabilities were tested both in the long and short-term. Results: The PaEO was obtained by steam distillation and the total extraction was reached after 3 hours yielding of 0.2% (w/w). This essential oil was characterized by physicochemical analyses for density [1.5 g.ml-1], refraction index [0.9167], ethanol 90% solubility [1:2], color, and appearance (yellow/clear). Nineteen components were identified in the oil, among them the sesquiterpenes: carvacrol [33.50%], p-cymene [28.20%] and γ-terpinene [14.77%]. The emulsions obtained successfully showed, for the first time, HLB values for essential oils from Plectranthus amboinicus [15.7]. Conclusion: The experimental data shows a relationship between HLB values of the surfactant mixtures contributing to the emulsified systems production containing phytopharmaceuticals. Such an approach is of great importance to the development of lipid carriers for therapeutic drugs. SUMMARY The essential oil from leaves of Plectranthus amboinicus was extracted by steam distillation and characterized.The emulsions containing essential oil were produced and the stability was performed in the short and long term.The critical hydrophilic-lipophilic balance (HLB) of the essential oil was 15.7 and was achieved by the combination of surfactants (Tween 80® and Span 20®). Abbreviations used: PaEO: essential oil of P. amboinicus, HLB: hydrophilic-lipophilic balance, CI: Creaming Index, MET: micro-emultocrit technique PMID:28216901

Elution of viruses by ionic and nonionic surfactants.

PubMed Central

Fujito, B T; Lytle, C D

1996-01-01

The ionic and nonionic surfactants sodium dodecyl sulfate and Triton X-100, respectively, eluted two viruses, phi X174 and PRD1, which were adsorbed to the ionic and nonionic binding membranes cationic polysulfone and nitrocellulose, respectively. Results indicated that complete elution was readily achieved only when combinations of surfactants and binding membranes were matched (i.e., ionic-ionic or nonionic-nonionic). PMID:8795240

Pharmacokinetics study of ferulic acid in rats after oral administration of γ-oryzanol under combined use of Tween 80 by LC/MS/MS.

PubMed

Pan, Y; Cai, L; He, S; Zhang, Z

2014-01-01

γ-oryzanol (OZ) is a rich source of commercially-important bioactive phytochemicals, most of them of interest in nutrition, pharmacy and cosmetics. However, the poor solubility of OZ limited the use. In the paper, ultraviolet-visible (UV-Vis) analysis was conducted to analysis the solubilization of OZ under combined use of Tween 80 in vitro. In addition, to further confirm the solubilizing effect of Tween 80, a pharmacokinetic study of ferulic acid (FA) in rats after oral administration of OZ 100 mg/kg under combined use of Tween 80 though LCMS/MS was carried out. Solubility enhancement as high as 100-fold is achieved using 1% Tween 80 in vitro. Following oral administration of OZ-Tween 80 100 mg/kg, the values of Tmax, Cmax, AUC0-∞, T1/2Ka and MRT0-∞ were 46.667 ± 39.328, 129.498 ± 27.025, 63738.28 ± 599, 14.274 ± 7.309 and 859.592 ± 108.780 respectively. The values of T1/2Ka, AUC0-∞, MRT0-t, and Tmax showed up to increase 16%, 58%, 44% and 47% while Cmax and CL/F decreased 22% and 12%, respectively. The decreased Cmax value indicated that Tween 80 can hardly enhance the absorption of FA in rats. However, T1/2Ka and Tmax values showed that the absorption of FA was extended, which resulted the increased values of AUC0-∞ and MRT0-∞. Our results reveal that Tween 80 improves solubility of OZ in vitro and could enhance the bioavailability of OZ by extending its absorption and elimination.

Effect of Tween 80 on formation of the superficial L1 layer of the Mycobacterium avium-Mycobacterium intracellulare complex.

PubMed Central

Masaki, S; Sugimori, G; Okamoto, A; Imose, J; Hayashi, Y

1991-01-01

The effects of Tween 80 supplementation of liquid culture medium on the formation of the superficial L1 layer of the Mycobacterium avium-Mycobacterium intracellulare complex (MAC) were examined by serological and scanning electron microscopic experiments. Specific antiserum to the glycopeptidolipids on the L1 layer of M. avium S-139, made in a rabbit, was used for seroagglutination reactions with antigens prepared from strain S-139 grown in medium supplemented with various levels of Tween 80 (0, 0.05, 0.5, 5, and 50 mg/ml). The agglutination titers gradually decreased as the concentration of Tween 80 rose. Scanning electron microscopy showed that the fibrillar materials consisting mainly of glycopeptidolipids on the L1 layer of strain S-139 also disappeared with increases in the concentration of Tween 80. In addition, there was no obvious correlation between (i) the plasmid DNAs and serotypes of MAC and (ii) formation of the L1 layer of MAC. It is therefore concluded that Tween 80 used to supplement liquid culture medium affects formation of the L1 layer, which has been considered to be one of the pathogenic factors of MAC. Images PMID:1885740

Non-sticky translocation of bio-molecules through Tween 20-coated solid-state nanopores in a wide pH range

NASA Astrophysics Data System (ADS)

Li, Xiaoqing; Hu, Rui; Li, Ji; Tong, Xin; Diao, J. J.; Yu, Dapeng; Zhao, Qing

2016-10-01

Nanopore-based sensing technology is considered high-throughput and low-cost for single molecule detection, but solid-state nanopores have suffered from pore clogging issues. A simple Tween 20 coating method is applied to ensure long-term (several hours) non-sticky translocation of various types of bio-molecules through SiN nanopores in a wide pH range (4.0-13.0). We also emphasize the importance of choosing appropriate concentration of Tween 20 coating buffer for desired effect. By coating nanopores with a Tween 20 layer, we are able to differentiate between single-stranded DNA and double-stranded DNA, to identify drift-dominated domain for single-stranded DNA, to estimate BSA volume and to observe the shape of individual nucleosome translocation event without non-specific adsorption. The wide pH endurance from 4.0 to 13.0 and the broad types of detection analytes including nucleic acids, proteins, and biological complexes highlight the great application potential of Tween 20-coated solid-state nanopores.

The VERB campaign's strategy for reaching African-American, Hispanic, Asian, and American Indian children and parents.

PubMed

Huhman, Marian; Berkowitz, Judy M; Wong, Faye L; Prosper, Erika; Gray, Michael; Prince, David; Yuen, Jeannie

2008-06-01

The VERB campaign promoted physical activity to U.S. children aged 9-13 years (tweens) by surrounding them with appealing messages that were associated with the VERB brand and tag line It's what you do! To maximize the impact of the campaign, VERB had a two-level strategy for its marketing. One level was designed to reach a general audience of tweens (i.e., most tweens who use mainstream media). The second level was designed specifically to reach four racial or ethnic audiences: African Americans, Hispanics, Asian Americans, and American Indians as an augmentation to the first level. This article focuses on VERB's market segmentation strategy and reports how messages for the general audience were adapted to reach specific racial or ethnic segments of the U.S. population. Findings are reported from qualitative studies conducted with tweens and the parents of tweens from these ethnic groups, and the marketing strategies used to reach each ethnic group and the results of evaluations of those strategies are also described.

Effect of tween 80 on nanoparticle preparation of modified chitosan for targeted delivery of combination doxorubicin and curcumin analogue

NASA Astrophysics Data System (ADS)

Sukmawati, Anita; Utami, Wahyu; Yuliani, Ratna; Da'i, Muhammad; Nafarin, Akhmad

2018-02-01

Delivery of anticancer is facing several problems including unspecific delivery of active substance to the targeted cell. The conjugation between chitosan and folate (chitosan-FA) was used for nanoparticle preparation containing combination of doxorubicin (DOX) and curcumin analogue, 2,5-bis-(4-hydroxi,3,5-dimethyl)-benzylidincylopentanone, as active substances. The purpose of this research is investigating formulation aspect for chitosan-FA nanoparticle by addition various tween 80 to achieve desired nano-size particle. The ionic gelation method was used for nanoparticle preparation using 0.05% w/v chitosan-FA with addition of 0.1 and 0.5% v/v of tween 80. The result showed that the high concentration of tween 80 during nanoparticle preparation lead to formation of smaller size particle. The 111.8 ±4.11 nm particle size was revealed by addition of 0.5% v/v tween 80 during chitosan-FA nanoparticle preparation loaded with active substances.

Purification and characterization of the tween-hydrolyzing esterase of Mycobacterium smegmatis.

PubMed Central

Tomioka, H

1983-01-01

An esterase hydrolyzing Tween 80 (polyoxyethylene sorbitan monooleate) was purified from sonicated cell lysates of Mycobacterium smegmatis ATCC 14468 by DEAE-cellulose, Sephadex G-150, phenyl Sepharose, and diethyl-(2-hydroxypropyl) aminoethyl column chromatography and by subsequent preparative polyacrylamide gel electrophoresis. The molecular weight was estimated to be 36,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 41,000 by gel filtration on a Sephadex G-150 column. The esterase contained a single polypeptide. The esterase was stable to heat treatment at 100 degrees C and to a wide range of pH. The temperature and pH optima for the hydrolysis of Tween 80 were 50 degrees C and 8.3, respectively. The esterase had a narrow substrate specificity; it exhibited a high activity only on compounds having both polyoxyethylene and fatty acyl moieties, such as Tweens. Monoacylglyceride was hydrolyzed more slowly by this esterase and this enzyme exhibited a nonspecific esterase activity on p-nitrophenyl acyl esters, especially those having short chain acyl moieties. The Km and Vmax were 19.2 mM and 1,670 mumol/min per mg of protein for Tween 20, 6.6 mM and 278 mumol/min per mg of protein for Tween 80, and 0.25 mM and 196 mumol/min per mg of protein for p-nitrophenyl acetate, respectively. Observations of the effects of various chemical modifications on the activity of the esterase indicated that tyrosine, histidine, arginine, and methionine (with tryptophan) residues may be active amino acids which play important roles in the expression of Tween 80-hydrolyzing activity of the enzyme. PMID:6885719

[The evaluation of lipolytic activity of strains of Staphylococcus epidermidis and Staphylococcus haemolyticus].

PubMed

Wróblewska, Joanna; Sekowska, Alicja; Zalas-Wiecek, Patrycja; Gospodarek, Eugenia

2011-01-01

A total of 103 isolates of CNS (66 strains of S. epidermidis and 37 strains of S. haemolyticus) were investigated. Lipolytic activity of staphylococcal strains was determined by Tryptic Soy Agar containing Tween 20 or Tween 60. The 95.4% strains of staphylococci demonstrated the lipolytic activity on Tween 20 agar and the 89.4% of strains of staphylococci degradation ester of fatty acids on Tweens 60 agar. We detected that S. epidermidis strains (respectively 95,4%, 89,4%) produced lipases more frequently than S. haemolyticus strains (respectively 72,9%, 59,4%). Studies suggest that source of isolation from clinical materials (blood, wound and pus) does not have an influence on the ability hydrolysis esters.

Inactivation of Herpes Simplex Viruses by Nonionic Surfactants

PubMed Central

Asculai, Samuel S.; Weis, Margaret T.; Rancourt, Martha W.; Kupferberg, A. B.

1978-01-01

Nonionic surface-active agents possessing ether or amide linkages between the hydrophillic and hydrophobic portions of the molecule rapidly inactivated the infectivity of herpes simplex viruses. The activity stemmed from the ability of nonionic surfactants to dissolve lipid-containing membranes. This was confirmed by observing surfactant destruction of mammalian cell plasma membranes and herpes simplex virus envelopes. Proprietary vaginal contraceptive formulations containing nonionic surfactants also inactivated herpes simplex virus infectivity. This observation suggests that nonionic surfactants in appropriate formulation could effectively prevent herpes simplex virus transmission. Images PMID:208460

Effect of hydroxypropylcellulose and Tween 80 on physicochemical properties and bioavailability of ezetimibe-loaded solid dispersion.

PubMed

Rashid, Rehmana; Kim, Dong Wuk; Din, Fakhar Ud; Mustapha, Omer; Yousaf, Abid Mehmood; Park, Jong Hyuck; Kim, Jong Oh; Yong, Chul Soon; Choi, Han-Gon

2015-10-05

The purpose of this research was to evaluate the effect of the HPC (hydroxypropylcellulose) and Tween 80 on the physicochemical properties and oral bioavailability of ezetimibe-loaded solid dispersions. The binary solid dispersions were prepared with drug and various amounts of HPC. Likewise, ternary solid dispersions were prepared with different ratios of drug, HPC and Tween 80. Both types of solid dispersions were prepared using the solvent evaporation method. Their aqueous solubility, physicochemical properties, dissolution and oral bioavailability were investigated in comparison with the drug powder. All the solid dispersions significantly improved the drug solubility and dissolution. As the amount of HPC increased in the binary solid dispersions to 10-fold, the drug solubility and dissolution were increased accordingly. However, further increase in HPC did not result in significant differences among them. Similarly, up to 0.1-fold, Tween 80 increased the drug solubility in the ternary solid dispersions followed by no significant change. However, Tween 80 hardly affected the drug dissolution. The physicochemical analysis proved that the drug in binary and ternary solid dispersion was existed in the amorphous form. The particle-size measurements of these formulations were also not significantly different from each other, which showed that Tween 80 had no impact on physicochemical properties. The ezetimibe-loaded binary and ternary solid dispersions gave 1.6- and 1.8-fold increased oral bioavailability in rats, respectively, as compared to the drug powder; however, these values were not significantly different from each other. Thus, HPC greatly affected the solubility, dissolution and oral bioavailability of drug, but Tween 80 hardly did. Furthermore, this ezetimibe-loaded binary solid dispersion prepared only with HPC would be suggested as a potential formulation for oral administration of ezetimibe. Copyright © 2015 Elsevier Ltd. All rights reserved.

Computed tomography-guided screening of surfactant effect on blood circulation time of emulsions: application to the design of an emulsion formulation for paclitaxel.

PubMed

Lee, Eun-Hye; Hong, Soon-Seok; Kim, So Hee; Lee, Mi-Kyung; Lim, Joon Seok; Lim, Soo-Jeong

2014-08-01

In an effort to apply the imaging techniques currently used in disease diagnosis for monitoring the pharmacokinetics and biodisposition of particulate drug carriers, we sought to use computed tomography (CT) scanning methodology to investigate the impact of surfactant on the blood residence time of emulsions. We prepared the iodinated oil Lipiodol emulsions with different compositions of surfactants and investigated the impact of surfactant on the blood residence time of emulsions by CT scanning. The blood circulation time of emulsions was prolonged by including Tween 80 or DSPE-PEG (polyethylene glycol 2000) in emulsions. Tween 80 was less effective than DSPE-PEG in terms of prolongation effect, but the blood circulating time of emulsions was prolonged in a Tween 80 content-dependent manner. As a proof-of-concept demonstration of the usefulness of CT-guided screening in the process of formulating drugs that need to be loaded in emulsions, paclitaxel was loaded in emulsions prepared with 87 or 65% Tween 80-containing surfactant mixtures. A pharmacokinetics study showed that paclitaxel loaded in 87% Tween 80 emulsions circulated longer in the bloodstream compared to those in 65% Tween 80 emulsions, as predicted by CT imaging. CT-visible, Lipiodol emulsions enabled the simple evaluation of surfactant composition effects on the biodisposition of emulsions.

An Improved Syringe Agroinfiltration Protocol to Enhance Transformation Efficiency by Combinative Use of 5-Azacytidine, Ascorbate Acid and Tween-20.

PubMed

Zhao, Huimin; Tan, Zilong; Wen, Xuejing; Wang, Yucheng

2017-02-14

Syringe infiltration is an important transient transformation method that is widely used in many molecular studies. Owing to the wide use of syringe agroinfiltration, it is important and necessary to improve its transformation efficiency. Here, we studied the factors influencing the transformation efficiency of syringe agroinfiltration. The pCAMBIA1301 was transformed into Nicotiana benthamiana leaves for investigation. The effects of 5-azacytidine (AzaC), Ascorbate acid (ASC) and Tween-20 on transformation were studied. The β-glucuronidase ( GUS ) expression and GUS activity were respectively measured to determine the transformation efficiency. AzaC, ASC and Tween-20 all significantly affected the transformation efficiency of agroinfiltration, and the optimal concentrations of AzaC, ASC and Tween-20 for the transgene expression were identified. Our results showed that 20 μM AzaC, 0.56 mM ASC and 0.03% ( v / v ) Tween-20 is the optimal concentration that could significantly improve the transformation efficiency of agroinfiltration. Furthermore, a combined supplement of 20 μM AzaC, 0.56 mM ASC and 0.03% Tween-20 improves the expression of transgene better than any one factor alone, increasing the transgene expression by more than 6-fold. Thus, an optimized syringe agroinfiltration was developed here, which might be a powerful method in transient transformation analysis.

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

Antibody adsorption on the surface of water studied by neutron reflection

PubMed Central

Li, Zongyi; Holman, Robert; Pan, Fang; Campbell, Richard A.; Campana, Mario; Li, Peixun; Webster, John R. P.; Bishop, Steven; Narwal, Rojaramani; Uddin, Shahid

2017-01-01

ABSTRACT Surface and interfacial adsorption of antibody molecules could cause structural unfolding and desorbed molecules could trigger solution aggregation, resulting in the compromise of physical stability. Although antibody adsorption is important and its relevance to many mechanistic processes has been proposed, few techniques can offer direct structural information about antibody adsorption under different conditions. The main aim of this study was to demonstrate the power of neutron reflection to unravel the amount and structural conformation of the adsorbed antibody layers at the air/water interface with and without surfactant, using a monoclonal antibody ‘COE-3′ as the model. By selecting isotopic contrasts from different ratios of H2O and D2O, the adsorbed amount, thickness and extent of the immersion of the antibody layer could be determined unambiguously. Upon mixing with the commonly-used non-ionic surfactant Polysorbate 80 (Tween 80), the surfactant in the mixed layer could be distinguished from antibody by using both hydrogenated and deuterated surfactants. Neutron reflection measurements from the co-adsorbed layers in null reflecting water revealed that, although the surfactant started to remove antibody from the surface at 1/100 critical micelle concentration (CMC) of the surfactant, complete removal was not achieved until above 1/10 CMC. The neutron study also revealed that antibody molecules retained their globular structure when either adsorbed by themselves or co-adsorbed with the surfactant under the conditions studied. PMID:28353420

Assessment of solubilization characteristics of different surfactants for carvedilol phosphate as a function of pH.

PubMed

Chakraborty, Subhashis; Shukla, Dali; Jain, Achint; Mishra, Brahmeshwar; Singh, Sanjay

2009-07-15

The effect of surfactants on the solubility of a new phosphate salt of carvedilol was investigated at different biorelevent pH to evaluate their solubilization capacity. Solutions of different classes of surfactants viz., anionic-sodium dodecyl sulfate (SDS) and sodium taurocholate (STC), cationic-cetyltrimethylammonium bromide (CTAB) and non-ionic-Tween 80 (T80) were prepared in the concentration range of 5-35 mmol dm(-3) in buffer solutions of pH 1.2, 3.0, 4.5, 5.8, 6.8 and 7.2. The solubility data were used to calculate the solubilization characteristics viz. molar solubilization capacity, water micelle partition coefficient, free energy of solubilization and binding constant. Solubility enhancement in basic pH was in following order: CTAB>T80>SDS>STC. CTAB and T80 showed remarkable solubility enhancement in acidic pH as well. Among the anionic surfactants, solubility in acidic medium was retarded except at pH 1.2 in case of SDS. Cationic and non-ionic surfactants were found to be suitable for enhancing the solubility of CP which can be employed for maintaining the in vitro sink condition in the basic dissolution medium. While anionic surfactants showed solubility retardant behavior which may be exploited in increasing the drug entrapment efficiency of a colloidal drug delivery system formulated by emulsification technique.

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.

Hyaluronan/Tween 80-assisted synthesis of silver nanoparticles for biological application

NASA Astrophysics Data System (ADS)

Li, Hui-Jun; Zhang, An-Qi; Sui, Li; Qian, Dong-Jin; Chen, Meng

2015-02-01

Water-soluble and well-stabilized silver nanoparticles (NPs) of small size have been synthesized using hyaluronan (HA) and Tween 80 as reducing and stabilizing agents. The effect of reaction conditions on the formation process of silver NPs was studied, and an aggregative growth mechanism of the silver NPs dominated in HA/Tween 80 system at pH 12 has been proposed. The obtained Ag NPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy. Moreover, the stability of the HA-Tween 80-silver NPs in normal saline was also studied, and a flexible blend membrane containing chitosan, gelatin, and the HA-Tween 80-silver NPs was prepared for further biological applications. Due to the high specific surface area and improved stability of silver NPs, the chitosan-gelatin-silver membrane has shown high antibacterial activity for strains of Escherichia coli. The cell viability tests indicate that the polymer membrane is non-cytotoxic to HepG2 cells, which might be attributed to its good biocompatibility.

Physical characterization and antioxidant activity of thymol solubilized Tween 80 micelles

PubMed Central

Deng, Ling-Li; Taxipalati, Maierhaba; Que, Fei; Zhang, Hui

2016-01-01

Attempts were made to solubilize thymol in Tween 80 micelle to study the solubilization mechanism of thymol and the effect of solubilization on its antioxidant activity. The maximum solubilized concentration of thymol in a 2.0% (w/v) Tween 80 micelle solution is 0.2 wt%. There was no significant difference in Z-average diameter between the empty micelles and thymol solubilized micelles. 1H NMR spectra indicated that 3-H and 4-H on the benzene ring of thymol interacted with the ester group between the hydrophilic head group and the hydrophobic tail group of Tween 80 by Van der Waals’ force. Ferric reducing antioxidant potential (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) assays showed that the reducing antioxidant activity of free thymol did not change after solubilized in Tween 80 micelles. Compared to free thymol, the solubilized thymol showed higher activities to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radicals. The present study suggested a possible preparation of thymol-carrying micelles with enhanced antioxidant activities that could be applied in food beverages. PMID:27905567

Physical characterization and antioxidant activity of thymol solubilized Tween 80 micelles.

PubMed

Deng, Ling-Li; Taxipalati, Maierhaba; Que, Fei; Zhang, Hui

2016-12-01

Attempts were made to solubilize thymol in Tween 80 micelle to study the solubilization mechanism of thymol and the effect of solubilization on its antioxidant activity. The maximum solubilized concentration of thymol in a 2.0% (w/v) Tween 80 micelle solution is 0.2 wt%. There was no significant difference in Z-average diameter between the empty micelles and thymol solubilized micelles. 1 H NMR spectra indicated that 3-H and 4-H on the benzene ring of thymol interacted with the ester group between the hydrophilic head group and the hydrophobic tail group of Tween 80 by Van der Waals' force. Ferric reducing antioxidant potential (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) assays showed that the reducing antioxidant activity of free thymol did not change after solubilized in Tween 80 micelles. Compared to free thymol, the solubilized thymol showed higher activities to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radicals. The present study suggested a possible preparation of thymol-carrying micelles with enhanced antioxidant activities that could be applied in food beverages.

Physical characterization and antioxidant activity of thymol solubilized Tween 80 micelles

NASA Astrophysics Data System (ADS)

Deng, Ling-Li; Taxipalati, Maierhaba; Que, Fei; Zhang, Hui

2016-12-01

Attempts were made to solubilize thymol in Tween 80 micelle to study the solubilization mechanism of thymol and the effect of solubilization on its antioxidant activity. The maximum solubilized concentration of thymol in a 2.0% (w/v) Tween 80 micelle solution is 0.2 wt%. There was no significant difference in Z-average diameter between the empty micelles and thymol solubilized micelles. 1H NMR spectra indicated that 3-H and 4-H on the benzene ring of thymol interacted with the ester group between the hydrophilic head group and the hydrophobic tail group of Tween 80 by Van der Waals’ force. Ferric reducing antioxidant potential (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) assays showed that the reducing antioxidant activity of free thymol did not change after solubilized in Tween 80 micelles. Compared to free thymol, the solubilized thymol showed higher activities to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radicals. The present study suggested a possible preparation of thymol-carrying micelles with enhanced antioxidant activities that could be applied in food beverages.

Enhance the anti-microorganism activity of cinnamon oil by xanthan gum as emulsifying agent

NASA Astrophysics Data System (ADS)

Lieu, Dong M.; Dang, Thuy T. K.; Nguyen, Huong T.

2018-04-01

The aim of this study was to evaluate the effect of emulsifying agents (tween 20, DMSO (Dimethyl Sulfoxide) and xanthan gum) to inhibit Escherichia coli; Staphylococcus aureus; Saccharomyces cerevisiae and Aspergillus niger by cinnamon oil (Cinnamomum Cassia). Cinnamon oil was added in the emulsifying agents independently: tween 20 (0.3% v/v). DMSO (0.3% v/v) and xanthan gum (0.3% w/v) at different concentrations and evaluated their anti-microorganism activity by agar disk diffusion, mycelial growth inhibition and growth inhibition in liquid phase. The result indicated that, cinnamon oil diluted in different emulsifying agents showed the difference of the anti-microorganism activity, in which DMSO showed the lowest result. Xanthan gum and tween 20 show good stable emulsion. The anti-microorganism effect of cinnamon oil in tween 20 and xanthan gum was not significant difference. However, cinnamon oil in xanthan gum showed anti-microorganism activity better than tween 20 at low concentration in agar disk diffusion. This suggests that, cinnamon oil could be encapsulated by xanthan gum to enhance the anti-microorganism activity.

Influence of sodium lauryl sulfate and tween 80 on carbamazepine-nicotinamide cocrystal solubility and dissolution behaviour.

PubMed

Li, Mingzhong; Qiao, Ning; Wang, Ke

2013-10-11

The influence of the surfactants of sodium lauryl sulfate (SLS) and Tween 80 on carbamazepine-nicotinamide (CBZ-NIC) cocrystal solubility and dissolution behaviour has been studied in this work. The solubility of the CBZ-NIC cocrystal was determined by measuring the eutectic concentrations of the drug and the coformer. Evolution of the intrinsic dissolution rate (IDR) of the CBZ-NIC cocrystal was monitored by the UV imaging dissolution system during dissolution. Experimental results indicated that SLS and Tween 80 had little influence upon the solubility of the CBZ-NIC cocrystal but they had totally opposite effects on the IDR of the CBZ-NIC cocrystal during dissolution. SLS significantly increased the IDR of the CBZ-NIC cocrystal while Tween 80 decreased its IDR.

Influence of Sodium Lauryl Sulfate and Tween 80 on Carbamazepine–Nicotinamide Cocrystal Solubility and Dissolution Behaviour

PubMed Central

Li, Mingzhong; Qiao, Ning; Wang, Ke

2013-01-01

The influence of the surfactants of sodium lauryl sulfate (SLS) and Tween 80 on carbamazepine–nicotinamide (CBZ–NIC) cocrystal solubility and dissolution behaviour has been studied in this work. The solubility of the CBZ–NIC cocrystal was determined by measuring the eutectic concentrations of the drug and the coformer. Evolution of the intrinsic dissolution rate (IDR) of the CBZ–NIC cocrystal was monitored by the UV imaging dissolution system during dissolution. Experimental results indicated that SLS and Tween 80 had little influence upon the solubility of the CBZ–NIC cocrystal but they had totally opposite effects on the IDR of the CBZ–NIC cocrystal during dissolution. SLS significantly increased the IDR of the CBZ–NIC cocrystal while Tween 80 decreased its IDR. PMID:24300560

Cloning, enhanced expression and characterization of an α-amylase gene from a wild strain in B. subtilis WB800.

PubMed

Chen, Jing; Chen, Xianghua; Dai, Jun; Xie, Guangrong; Yan, Luying; Lu, Lina; Chen, Jianhua

2015-09-01

A Bacillus strain with high productivity of α-amylase isolated from a starch farm was identified as Bacillus amyloliquefaciens. The α-amylase encoding gene amy1 was cloned into pMD18-T vector and amplified in E. coli DH5α. Shuttle vector pP43MNX was reconstructed to obtain vector pP43X for heterologous expression of the α-amylase in B. subtilis WB800. Recombinant enzyme was sufficiently purified by precipitation, gel filtration and anion exchange with a specific activity of 5566 U/mg. The α-amylase sequence contains an open reading frame of 1545 bp, which encodes a protein of 514 amino acid residues with a predicted molecular mass of 58.4 kDa. The enzyme exhibited maximal activity at pH 6.0 and 60 °C. Catalytic efficiency of the recombinant α-amylase was inhibited by Hg(2+), Pb(2+) and Cu(2+), but stimulated by Li(+), Mn(2+) and Ca(2+). The purified enzyme showed decreased activity toward detergents (SDS, Tween 20 and Triton X-100). Compared with production by the wild strain, there was a 1.48-fold increase in the productivity of α-amylase in recombinant B. subtilis WB800. Copyright © 2015 Elsevier B.V. All rights reserved.

Partial Characterization of the Proteolytic Properties of an Enzymatic Extract From "Aguama" Bromelia pinguin L. Fruit Grown in Mexico.

PubMed

Moreno-Hernández, Jesús Martín; Hernández-Mancillas, Xitlalli Desideria; Navarrete, Evelia Lorena Coss; Mazorra-Manzano, Miguel Ángel; Osuna-Ruiz, Idalia; Rodríguez-Tirado, Víctor Alfonso; Salazar-Leyva, Jesús Aarón

2017-05-01

Plant proteases are capable of performing several functions in biological systems, and their use is attractive for biotechnological process due to their interesting catalytic properties. Bromelia pinguin (aguama) is a wild abundant natural resource in several regions of Central America and the Caribbean Islands but is underutilized. Their fruits are rich in proteases with properties that are still unknown, but they represent an attractive source of enzymes for biotechnological applications. Thus, the proteolytic activity in enzymatic crude extracts (CEs) from wild B. pinguin fruits was partially characterized. Enzymes in CEs showed high proteolytic activity at acid (pH 2.0-4.0) and neutral alkaline (pH 7.0-9.0) conditions, indicating that different types of active proteases are present. Proteolytic activity inhibition by the use of specific protease inhibitors indicated that aspartic, cysteine, and serine proteases are the main types of proteases present in CEs. Activity at pH 3.0 was stable in a broad range of temperatures (25-50 °C) and retained its activity in the presence of surfactants (SDS, Tween-80), reducing agents (DTT, 2-mercapoethanol), and organic solvents (methanol, ethanol, acetone, 2-propanol), which suggests that B. pinguin proteases are potential candidates for their application in brewing, detergent, and pharmaceutical industries.

Aortic valve cell seeding into decellularized animal pericardium by perfusion-assisted bioreactor.

PubMed

Amadeo, Francesco; Boschetti, Federica; Polvani, Gianluca; Banfi, Cristina; Pesce, Maurizio; Santoro, Rosaria

2018-04-27

Animal-derived pericardium is the elective tissue employed in manufacturing heart valve prostheses. The preparation of this tissue for biological valve production consists of fixation with aldehydes, which reduces, but not eliminates, the xenoantigens and the donor cellular material. As a consequence, especially in patients below 65-70 years of age, the employment of valve substitutes contaning pericardium is not indicated due to progressive calcification that causes tissue degeneration and recurrence of valve insufficiency. Decellularization with ionic or nonionic detergents has been proposed as an alternative procedure to prepare aldehyde- or xenoantigen-free pericardium for biological valve manufacturing. In the present contribution, we optimized a decellularization procedure that is permissive for seeding and culturing valve competent cells able to colonize and reconstitute a valve-like tissue. A high-efficiency cellularization was achieved by forcing cell penetration inside the pericardium matrix using a perfusion bioreactor. Because the decellularization procedure was found not to alter the collagen composition of the pericardial matrix and cells seeded in the tissue constructs consistently grew and acquired the phenotype of "quiescent" valve interstitial cells, our investigation sets a novel standard in pericardium application for tissue engineering of "living" valve implants. Copyright © 2018 John Wiley & Sons, Ltd.

[Occupational risks in grocery stores].

PubMed

Graziosi, Francesca; Bonfiglioli, Roberta; Violante, Francesco S

2014-01-01

This work provides an overview of the spectrum of possible occupational risk factors in the retail grocery store/supermarket workplace. Literature on this theme, obtained consulting PubMed database and Google Scholar, was checked. We also exjlore results from the National bInstitute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA). RESULTs: Contacts with objects, use of dangerous equipment (cutter, food slicer) and falls to the same level (slips, trips and falls) are the mainly described workplace hazards. Exposure to chemical (flour dust, components of detergents or disinfectants, volatile organic compounds and contact with nickel) and physical agents (cold exposure, nonionizing radiation and whole bpdy vibration) are reported by many authors. Relations between biomechanical and ergonomic risk factors and musculoskeletal disorders represent the main subjects of study. Few studies are found about biological agents (particularly among butchers). Data regarding psychosocial risks factors in this setting are still limited. Musculoskeletal disorders continue to be the most recurrent health problem between the grocery store workers (particularly low back pain and carpal tunnel syndrome among cashiers). Many technical documents and international Srecommendations are present to prevent these kinds of disorders. Psychosocial risk factors and risk of workplace violence should deserve further investigation.

Microsomal epoxide hydrolase of rat liver. Purification and characterization of enzyme fractions with different chromatographic characteristics.

PubMed Central

Bulleid, N J; Graham, A B; Craft, J A

1986-01-01

Microsomal epoxide hydrolase was purified from rat liver, and different fractions of the purified enzyme, which varied in their contents of phospholipid, were obtained by ion-exchange chromatography. One fraction (A), which did not bind to CM-cellulose, had a high phospholipid content, and a second fraction (B), which was eluted from CM-cellulose at high ionic strength, had a low phospholipid content. Removal of most of the phospholipid from fraction A altered its chromatographic behaviour. When the delipidated material was re-applied to CM-cellulose, most of the enzyme bound to the cation-exchanger. The specific activities of all the fractions described (with styrene epoxide [(1,2-epoxyethyl)benzene] as substrate) were altered by adding the non-ionic detergent Lubrol PX or phospholipid. Lubrol PX inhibited enzyme activity, and phospholipid reversed this inhibition. The various enzyme fractions isolated appeared to be different forms of the same protein, as judged by their minimum Mr values and immunochemical properties. These results indicate that different fractions of epoxide hydrolase isolated by ion-exchange chromatography probably are not different isoenzyme forms. Images Fig. 2. Fig. 3. PMID:3082328

Leucaena sp. recombinant cinnamyl alcohol dehydrogenase: purification and physicochemical characterization.

PubMed

Patel, Parth; Gupta, Neha; Gaikwad, Sushama; Agrawal, Dinesh C; Khan, Bashir M

2014-02-01

Cinnamyl alcohol dehydrogenase is a broad substrate specificity enzyme catalyzing the final step in monolignol biosynthesis, leading to lignin formation in plants. Here, we report characterization of a recombinant CAD homologue (LlCAD2) isolated from Leucaena leucocephala. LlCAD2 is 80 kDa homo-dimer associated with non-covalent interactions, having substrate preference toward sinapaldehyde with Kcat/Km of 11.6×10(6) (M(-1) s(-1)), and a possible involvement of histidine at the active site. The enzyme remains stable up to 40 °C, with the deactivation rate constant (Kd(*)) and half-life (t1/2) of 0.002 and 5h, respectively. LlCAD2 showed optimal activity at pH 6.5 and 9 for reduction and oxidation reactions, respectively, and was stable between pH 7 and 9, with the deactivation rate constant (Kd(*)) and half-life (t1/2) of 7.5×10(-4) and 15 h, respectively. It is a Zn-metalloenzyme with 4 Zn(2+) per dimer, however, was inhibited in presence of externally supplemented Zn(2+) ions. The enzyme was resistant to osmolytes, reducing agents and non-ionic detergents. Copyright © 2013 Elsevier B.V. All rights reserved.

A MODIFIED PROTEIN ASSAY FROM MICROGRAM TO LOW NANOGRAM LEVELS IN DILUTE SAMPLES

PubMed Central

Heda, Ghanshyam D.; Kunwar, Upasana; Heda, Rajiv P.

2013-01-01

In this paper we present a modified and improved protein assay that was previously described as ‘amidoschwarz assay’ by Schaffner and Weissmann (Anal. Biochem. 56, 1973, 502–514). Our improved protein assay is user-friendly and 30 to 40 times more sensitive than the earlier method. The assay was developed into 3 formats (maco, micro, and nanoassay) with TCA as protein precipitating agent; measuring up to 96 samples. The macro and micro formats of this assay require a single reagent staining with amido black of protein dots, bound to nitrocellulose membrane with lowest protein measurements to 1 μg and 0.1 μg respectively. The nanoassay on the other hand with combination staining of amido black followed by colloidal gold can extend the detection limit to 2.5 ng of protein. Protein concentrations were determined by densitometry and/or spectrophotometry. This assay is compatible with many ionic and non-ionic detergents. This improved protein assay provides an additional choice to researchers in measuring total protein concentration accurately in dilute biological samples as low as 0.125 μg/ml, prior to their biochemical analysis such as in comparative proteomics. PMID:24135655

Streptococcal M protein extracted by nonionic detergent. III. Correlation between immunological cross-reactions and structural similarities with implications for antiphagocytosis

PubMed Central

1978-01-01

Three immunologically cross-reactive and non-cross-reactive streptococcal M proteins were analyzed by a chromatographic tryptic peptide mapping system. The results indicate that cross-reactions correlate with the extent of structural similarity among the M protein molecules analyzed. The data also reveal that free lysine is released by the action of trypsin from these three M proteins, suggesting a common lys-lys or arg-lys sequence. In addition, only one peptide has been found to be common within all three M types. This limited structural relatedness among the three M proteins examined indicates that sequence variation plays a major role in the immunological specificity of the M antigens. However, despite sequence variation, all M protein molecules have a common antiphagocytic activity. The fact that no common opsonic antibody has yet been found, even against limited M types, argues against this biological activity being solely the result of a common sequence. Based on these data, it is suggested that the antiphagocytic effect of M protein may be due to a conformationally created environment on the surface of the molecule which is selected by both immunological and biological pressure. PMID:355596

Mesoscale organization of domains in the plasma membrane - beyond the lipid raft.

PubMed

Lu, Stella M; Fairn, Gregory D

2018-04-01

The plasma membrane is compartmentalized into several distinct regions or domains, which show a broad diversity in both size and lifetime. The segregation of lipids and membrane proteins is thought to be driven by the lipid composition itself, lipid-protein interactions and diffusional barriers. With regards to the lipid composition, the immiscibility of certain classes of lipids underlies the "lipid raft" concept of plasmalemmal compartmentalization. Historically, lipid rafts have been described as cholesterol and (glyco)sphingolipid-rich regions of the plasma membrane that exist as a liquid-ordered phase that are resistant to extraction with non-ionic detergents. Over the years the interest in lipid rafts grew as did the challenges with studying these nanodomains. The term lipid raft has fallen out of favor with many scientists and instead the terms "membrane raft" or "membrane nanodomain" are preferred as they connote the heterogeneity and dynamic nature of the lipid-protein assemblies. In this article, we will discuss the classical lipid raft hypothesis and its limitations. This review will also discuss alternative models of lipid-protein interactions, annular lipid shells, and larger membrane clusters. We will also discuss the mesoscale organization of plasmalemmal domains including visible structures such as clathrin-coated pits and caveolae.

Efficient biotransformation of herbicide diuron by bacterial strain Micrococcus sp. PS-1.

PubMed

Sharma, Priyanka; Chopra, Adity; Cameotra, Swaranjit Singh; Suri, C Raman

2010-11-01

A Gram-positive, Micrococcus sp. strain PS-1 capable of utilizing phenylurea herbicide diuron as a sole carbon source at a high concentration (up to 250 ppm) was isolated from diuron storage site by selective enrichment study. The taxonomic characterization with 16S rRNA gene sequencing (1,477 bp) identified PS-1 as a member of Micrococcus sp. It was studied for the degradation of diuron and a range of its analogues (monuron, linuron, monolinuron, chlortoluron and fenuron). The shake flasks experiments demonstrated fast degradation of diuron (up to 96% at 250 ppm within 30 h incubation) with the addition of small quantity (0.01%) of non-ionic detergent. The relative degradation profile by the isolate was in the order of fenuron > monuron > diuron > linuron > monolinuron > chlortoluron. Further, the biochemical characterization of catabolic pathway by spectroscopic and chromatographic techniques demonstrated that the degradation proceeded via formation of dealkylated metabolites to form 3,4-dichloroaniline (3,4-DCA). It was the major metabolite formed, associated with profound increase in degradation kinetics in presence of appropriate additive.

Probing the temperature-dependent changes of the interfacial hydration and viscosity of Tween20 : cholesterol (1 : 1) niosome membrane using fisetin as a fluorescent molecular probe.

PubMed

Mishra, Jhili; Swain, Jitendriya; Mishra, Ashok Kumar

2018-05-16

A detailed photophysical study of fisetin in a Tween20 : cholesterol (1 : 1) niosome membrane has been carried out. Fisetin is found to partition well into the Tween20 : cholesterol (1 : 1) niosome membrane at low temperature (Kp = 2.7 × 104 M-1 at 10 °C). Cetylpyridinium chloride quenching study confirms the location of fisetin molecules in the interfacial domain of Tween20 : cholesterol (1 : 1) niosome membrane. The emission from the prototropic forms of fisetin (neutral form, excited state anion, ground state anion and phototautomer form) is found to sensitively reflect the local heterogeneities in Tween20 : cholesterol (1 : 1) niosome membrane. The shift in anionic emission maximum with variation in temperature shows the sensitivity of fisetin towards water accessibility at the interfacial domain of Tween20 : cholesterol (1 : 1) niosome membrane. Zeta potential value confirms that there is no role of surface charge in the multiple prototropism of fisetin in Tween20 : cholesterol (1 : 1) niosome membrane. The microviscosity changes with temperature, as reflected in fluorescence anisotropy values of fisetin phototautomeric species FT*, give information about the temperature-induced changes in the motional resistance offered by the interfacial domain of the niosomal membrane to small molecules. A temperature-dependent fluorescence lifetime study confirms the distribution of FT* in the two different sites of niosomal interfacial domain, i.e. water-deficient inner site and water-accessible outer site. This heterogeneity in distribution of FT* is further confirmed through time-resolved fluorescence anisotropy decay resulting in two different rotational time constants (faster component of ∼1.04 ns originates from water-accessible outer site and slower component of ∼16.50 ns originates from water-deficient inner site). The interfacial location of fisetin in Tween20 : cholesterol (1 : 1) niosome membrane has an important implication with regards to antioxidant activity as confirmed from a DPPH radical scavenging study.

Enhanced chemiluminescence of cerium(IV)-Tween 85 system and the analytical application.

PubMed

Li, Shifeng; Qian, Li; Zhu, Yan; Liu, Manman; Gao, Yinping; Ni, Yonghong

2013-01-01

The oxidation reaction between cerium(IV) and Tween 85 in sulfuric acid medium produced weak chemiluminescence (CL). In this paper, it was found that citrate could strongly enhance the CL of cerium(IV)-Tween 85-polyphenol system. Based on studies of ultraviolet-visible spectra and CL spectra, the CL enhancement mechanism had been proposed. It was surmised that the light emission was from an excited oxygen molecular pair O2((1)Δg)O2((1)∑g(-)). The maximum emission wavelength was about 478 nm. The effects of 17 amino acids and 29 organic compounds on cerium(IV)-Tween 85-citrate CL were investigated by a flow injection procedure. This study showed the present system had a wide application for the determination of these compounds. Copyright © 2012 John Wiley & Sons, Ltd.

Detergent-compatible proteases: microbial production, properties, and stain removal analysis.

PubMed

Niyonzima, Francois Niyongabo; More, Sunil

2015-01-01

Proteases are one of the most important commercial enzymes used in various industrial domains such as detergent and leather industries. The alkaline proteases as well as other detergent-compatible enzymes such as lipases and amylases serve now as the key components in detergent formulations. They break down various stains during fabric washing. The search for detergent-compatible proteases with better properties is a continuous exercise. The current trend is to use detergent-compatible proteases that are stable over a wide temperature range. Although the proteases showing stability at elevated pH have the capacity to be used in detergent formulations, their usage can be significant if they are also stable and compatible with detergent and detergent ingredients, and also able to remove protein stains. Despite the existence of some reviews on alkaline proteases, there is no specification for the use of alkaline proteases as detergent additives. The present review describes the detergent-compatible proteases tested as detergent additives. An overview was provided for screening, optimization, purification, and properties of detergent compatible proteases, with an emphasis on the stability and compatibility of the alkaline proteases with the detergent and detergent compounds, as well as stain removal examination methods.

Coproduction of detergent compatible bacterial enzymes and stain removal evaluation.

PubMed

Niyonzima, Francois N; More, Sunil S

2015-10-01

Most of the detergents that are presently produced contain the detergent compatible enzymes to improve and accelerate the washing performance by removing tough stains. The process is environment friendly as the use of enzymes in the detergent formulation reduces the utilization of toxic detergent constituents. The current trend is to use the detergent compatible enzymes that are active at low and ambient temperature in order to save energy and maintain fabric quality. As the detergent compatible bacterial enzymes are used together in the detergent formulation, it is important to co-produce the detergent enzymes in a single fermentation medium as the enzyme stability is assured, and production cost gets reduced enormously. The review reports on the production, purification, characterization and application of detergent compatible amylases, lipases, and proteases are available. However, there is no specific review or minireview on the concomitant production of detergent compatible amylases, lipases, and proteases. In this minireview, the coproduction of detergent compatible enzymes by bacterial species, enzyme stability towards detergents and detergent components, and stain release analysis were discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of auxin-binding proteins from zucchini plasma membrane

NASA Technical Reports Server (NTRS)

Hicks, G. R.; Rice, M. S.; Lomax, T. L.

1993-01-01

We have previously identified two auxin-binding polypeptides in plasma membrane (PM) preparations from zucchini (Cucurbita pepo L.) (Hicks et al. 1989, Proc. Natl. Acad. Sci. USA 86, 4948-4952). These polypeptides have molecular weights of 40 kDa and 42 kDa and label specifically with the photoaffinity auxin analog 5-N3-7-3H-IAA (azido-IAA). Azido-IAA permits both the covalent and radioactive tagging of auxin-binding proteins and has allowed us to characterize further the 40-kDa and 42-kDa polypeptides, including the nature of their attachment to the PM, their relationship to each other, and their potential function. The azido-IAA-labeled polypeptides remain in the pelleted membrane fraction following high-salt and detergent washes, which indicates a tight and possibly integral association with the PM. Two-dimensional electrophoresis of partially purified azido-IAA-labeled protein demonstrates that, in addition to the major isoforms of the 40-kDa and 42-kDa polypeptides, which possess isoelectric points (pIs) of 8.2 and 7.2, respectively, several less abundant isoforms that display unique pIs are apparent at both molecular masses. Tryptic and chymotryptic digestion of the auxin-binding proteins indicates that the 40-kDa and 42-kDa polypeptides are closely related or are modifications of the same polypeptide. Phase extraction with the nonionic detergent Triton X-114 results in partitioning of the azido-IAA-labeled polypeptides into the aqueous (hydrophilic) phase. This apparently paradoxical behavior is also exhibited by certain integral membrane proteins that aggregate to form channels. The results of gel filtration indicate that the auxin-binding proteins do indeed aggregate strongly and that the polypeptides associate to form a dimer or multimeric complex in vivo. These characteristics are consistent with the hypothesis that the 40-kDa and 42-kDa polypeptides are subunits of a multimeric integral membrane protein which has an auxin-binding site, and which may possess transporter or channel function.

Weak and Saturable Protein–Surfactant Interactions in the Denaturation of Apo-α-Lactalbumin by Acidic and Lactonic Sophorolipid

PubMed Central

Andersen, Kell K.; Vad, Brian S.; Roelants, Sophie; van Bogaert, Inge N. A.; Otzen, Daniel E.

2016-01-01

Biosurfactants are of growing interest as sustainable alternatives to fossil-fuel-derived chemical surfactants, particularly for the detergent industry. To realize this potential, it is necessary to understand how they affect proteins which they may encounter in their applications. However, knowledge of such interactions is limited. Here, we present a study of the interactions between the model protein apo-α-lactalbumin (apo-aLA) and the biosurfactant sophorolipid (SL) produced by the yeast Starmerella bombicola. SL occurs both as an acidic and a lactonic form; the lactonic form (lactSL) is sparingly soluble and has a lower critical micelle concentration (cmc) than the acidic form [non-acetylated acidic sophorolipid (acidSL)]. We show that acidSL affects apo-aLA in a similar way to the related glycolipid biosurfactant rhamnolipid (RL), with the important difference that RL is also active below the cmc in contrast to acidSL. Using isothermal titration calorimetry data, we show that acidSL has weak and saturable interactions with apo-aLA at low concentrations; due to the relatively low cmc of acidSL (which means that the monomer concentration is limited to ca. 0–1 mM SL), it is only possible to observe interactions with monomeric acidSL at high apo-aLA concentrations. However, the denaturation kinetics of apo-aLA in the presence of acidSL are consistent with a collaboration between monomeric and micellar surfactant species, similar to RL and non-ionic or zwitterionic surfactants. Inclusion of diacetylated lactonic sophorolipid (lactSL) as mixed micelles with acidSL lowers the cmc and this effectively reduces the rate of unfolding, emphasizing that SL like other biosurfactants is a gentle anionic surfactant. Our data highlight the potential of these biosurfactants for future use in the detergent and pharmaceutical industry. PMID:27877155

Characterization of auxin-binding proteins from zucchini plasma membrane.

PubMed

Hicks, G R; Rice, M S; Lomax, T L

1993-01-01

We have previously identified two auxin-binding polypeptides in plasma membrane (PM) preparations from zucchini (Cucurbita pepo L.) (Hicks et al. 1989, Proc. Natl. Acad. Sci. USA 86, 4948-4952). These polypeptides have molecular weights of 40 kDa and 42 kDa and label specifically with the photoaffinity auxin analog 5-N3-7-3H-IAA (azido-IAA). Azido-IAA permits both the covalent and radioactive tagging of auxin-binding proteins and has allowed us to characterize further the 40-kDa and 42-kDa polypeptides, including the nature of their attachment to the PM, their relationship to each other, and their potential function. The azido-IAA-labeled polypeptides remain in the pelleted membrane fraction following high-salt and detergent washes, which indicates a tight and possibly integral association with the PM. Two-dimensional electrophoresis of partially purified azido-IAA-labeled protein demonstrates that, in addition to the major isoforms of the 40-kDa and 42-kDa polypeptides, which possess isoelectric points (pIs) of 8.2 and 7.2, respectively, several less abundant isoforms that display unique pIs are apparent at both molecular masses. Tryptic and chymotryptic digestion of the auxin-binding proteins indicates that the 40-kDa and 42-kDa polypeptides are closely related or are modifications of the same polypeptide. Phase extraction with the nonionic detergent Triton X-114 results in partitioning of the azido-IAA-labeled polypeptides into the aqueous (hydrophilic) phase. This apparently paradoxical behavior is also exhibited by certain integral membrane proteins that aggregate to form channels. The results of gel filtration indicate that the auxin-binding proteins do indeed aggregate strongly and that the polypeptides associate to form a dimer or multimeric complex in vivo. These characteristics are consistent with the hypothesis that the 40-kDa and 42-kDa polypeptides are subunits of a multimeric integral membrane protein which has an auxin-binding site, and which may possess transporter or channel function.

Surface-enhanced Raman spectroscopy (SERS) tracking of chelerythrine, a Na(+)/K(+) pump inhibitor, into cytosol and plasma membrane fractions of human lens epithelial cell cultures.

PubMed

Dorney, Kevin M; Sizemore, Ioana E P; Alqahtani, Tariq; Adragna, Norma C; Lauf, Peter K

2013-01-01

The quaternary benzo-phenanthridine alkaloid (QBA) chelerythrine (CET) is a pro-apoptotic drug and Na(+)/K(+) pump (NKP) inhibitor in human lens epithelial cells (HLECs). In order to obtain further insight into the mechanism of NKP inhibition by CET, its sub-cellular distribution was quantified in cytosolic and membrane fractions of HLEC cultures by surface-enhanced Raman spectroscopy (SERS). Silver nanoparticles (AgNPs) prepared by the Creighton method were concentrated, and size-selected using a one-step tangential flow filtration approach. HLECs cultures were exposed to 50 μM CET in 300 mOsM phosphate-buffered NaCl for 30 min. A variety of cytosolic extracts, crude and purified membranes, prepared in lysing solutions in the presence and absence of a non-ionic detergent, were incubated with AgNPs and subjected to SERS analysis. Determinations of CET were based on a linear calibration plot of the integrated CET SERS intensity at its 659 cm(-1) marker band as a function of CET concentration. SERS detected chemically unaltered CET in both cytosol and plasma membrane fractions. Normalized for protein, the CET content was some 100 fold higher in the crude and purified plasma membrane fraction than in the soluble cytosolic extract. The total free CET concentration in the cytosol, free of membranes or containing detergent-solubilized membrane material, approached that of the incubation medium of HLECs. Given a negative membrane potential of HLECs the data suggest, but do not prove, that CET may traverse the plasma membrane as a positively charged monomer (CET(+)) accumulating near or above passive equilibrium distribution. These findings may contribute to a recently proposed hypothesis that CET binds to and inhibits the NKP through its cytosolic aspect. © 2014 S. Karger AG, Basel.

Vitamin A losses to plastic intravenous infusion devices and an improved method of delivery.

PubMed

Gutcher, G R; Lax, A A; Farrell, P M

1984-07-01

This study was designed to reevaluate the kinetics of vitamin A losses in the plastic intravenous infusion system used clinically in premature infants and to attempt to establish an improved method of delivery that would avoid significant and unpredictable losses. The losses of retinol, retinyl acetate, and retinyl palmitate were assessed in the presence of various concentrations of the emulsifier Tween 20. For a period of more than 24 h and at a concentration of 0.0085% Tween 20, retinol and retinyl acetate were delivered at 17.4 and 33.9% of the originally intended dose, respectively, while retinyl palmitate was at 100%. At 1% Tween 20, retinyl acetate was completely delivered but even at 2% Tween 20 only 51% of the retinol was delivered. The data suggest that predictable infusions of vitamin A may be attained by using retinyl palmitate rather than retinol in multivitamin preparations.

Detergent-compatible bacterial amylases.

PubMed

Niyonzima, Francois N; More, Sunil S

2014-10-01

Proteases, lipases, amylases, and cellulases are enzymes used in detergent formulation to improve the detergency. The amylases are specifically supplemented to the detergent to digest starchy stains. Most of the solid and liquid detergents that are currently manufactured contain alkaline enzymes. The advantages of using alkaline enzymes in the detergent formulation are that they aid in removing tough stains and the process is environmentally friendly since they reduce the use of toxic detergent ingredients. Amylases active at low temperature are preferred as the energy consumption gets reduced, and the whole process becomes cost-effective. Most microbial alkaline amylases are used as detergent ingredients. Various reviews report on the production, purification, characterization, and application of amylases in different industry sectors, but there is no specific review on bacterial or fungal alkaline amylases or detergent-compatible amylases. In this mini-review, an overview on the production and property studies of the detergent bacterial amylases is given, and the stability and compatibility of the alkaline bacterial amylases in the presence of the detergents and the detergent components are highlighted.

Messages about appearance, food, weight and exercise in "tween" television.

PubMed

Simpson, Courtney C; Kwitowski, Melissa; Boutte, Rachel; Gow, Rachel W; Mazzeo, Suzanne E

2016-12-01

Tweens (children ages ~8-14years) are a relatively recently defined age group, increasingly targeted by marketers. Individuals in this age group are particularly vulnerable to opinions and behaviors presented in media messages, given their level of cognitive and social development. However, little research has examined messages about appearance, food, weight, and exercise in television specifically targeting tweens, despite the popularity of this media type among this age group. This study used a content analytic approach to explore these messages in the five most popular television shows for tweens on the Disney Channel (as of 2015). Using a multiple-pass approach, relevant content in episodes from the most recently completed seasons of each show was coded. Appearance related incidents occurred in every episode; these most frequently mentioned attractiveness/beauty. Food related incidents were also present in every episode; typically, these situations were appearance and weight neutral. Exercise related incidents occurred in 53.3% of episodes; the majority expressed resistance to exercise. Weight related incidents occurred in 40.0% of the episodes; the majority praised the muscular ideal. Women were more likely to initiate appearance incidents, and men were more likely to initiate exercise incidents. These results suggest that programs specifically marketed to tweens reinforce appearance ideals, including stereotypes about female attractiveness and male athleticism, two constructs linked to eating pathology and body dissatisfaction. Given the developmental vulnerability of the target group, these findings are concerning, and highlight potential foci for prevention programming, including media literacy, for tweens. Copyright © 2016 Elsevier Ltd. All rights reserved.

Availability of manufacturers' information on efficacy and compatibility of detergents used for cleaning dental instruments.

PubMed

Calvert, G; Murray, C A; Smith, A J; Hurrell, D

2012-05-25

To review physico-chemical data supplied for commercially available detergents marketed for manual and/or ultrasonic cleansing of reusable dental instruments. Manufacturers/suppliers of commercially available detergents for manual or ultrasonic cleaning of dental instruments within primary dental care were invited to supply product information. A structured questionnaire requested details on a range of physical and chemical properties for each detergent. Seventeen detergent manufacturers/suppliers, encompassing 31 commercially available detergents were identified. Ten of the 17 manufacturers provided information on 23 (74%) of the detergent formulations. Nine detergents were of neutral pH, ten mild alkalis (pH 7.5-10.5) and four strong alkalis (pH >10.5). Sixteen detergents were recommended for ultrasonic and manual cleaning, four stated ultrasonic use and three manual only. Ten detergents cited enzymatic activity as their main mode of action, but only six manufacturers provided detailed information. Four detergents recommended by manufacturers as suitable for manual washing had a strong alkaline pH (>10.5), presenting chemical hazards to users. Two strong alkaline detergents did not warn users of potential adverse effects of such alkaline solutions (corrosion) upon aluminium containing instruments. Only one detergent had investigated the potential toxicity of detergent residuals remaining on instruments after reprocessing. It has proven challenging to collate physico-chemical data on detergents suitable for use in manual and/or ultrasonic cleaning of dental instruments in general dental practice. Standardisation of information on the nature and efficacy of dental detergents in a readily accessible form would be beneficial to dental practice.

Summary of: availability of manufacturers' information on efficacy and compatibility of detergents used for cleaning dental instruments.

PubMed

Barker, Chris

2012-05-25

To review physico-chemical data supplied for commercially available detergents marketed for manual and/or ultrasonic cleansing of reusable dental instruments. Manufacturers/suppliers of commercially available detergents for manual or ultrasonic cleaning of dental instruments within primary dental care were invited to supply product information. A structured questionnaire requested details on a range of physical and chemical properties for each detergent. Seventeen detergent manufacturers/suppliers, encompassing 31 commercially available detergents were identified. Ten of the 17 manufacturers provided information on 23 (74%) of the detergent formulations. Nine detergents were of neutral pH, ten mild alkalis (pH 7.5-10.5) and four strong alkalis (pH >10.5). Sixteen detergents were recommended for ultrasonic and manual cleaning, four stated ultrasonic use and three manual only. Ten detergents cited enzymatic activity as their main mode of action, but only six manufacturers provided detailed information. Four detergents recommended by manufacturers as suitable for manual washing had a strong alkaline pH (>10.5), presenting chemical hazards to users. Two strong alkaline detergents did not warn users of potential adverse effects of such alkaline solutions (corrosion) upon aluminium containing instruments. Only one detergent had investigated the potential toxicity of detergent residuals remaining on instruments after reprocessing. It has proven challenging to collate physico-chemical data on detergents suitable for use in manual and/or ultrasonic cleaning of dental instruments in general dental practice. Standardisation of information on the nature and efficacy of dental detergents in a readily accessible form would be beneficial to dental practice.

Effect of surfactant concentration and solidification temperature on the characteristics and stability of nanostructured lipid carrier (NLC) prepared from rambutan (Nephelium lappaceum L.) kernel fat.

PubMed

Witayaudom, Pimchanok; Klinkesorn, Utai

2017-11-01

Nanostructured lipid carrier (NLC) was fabricated from rambutan (Nephelium lappaceum L.) kernel fat stabilized with Tween 80 in this present work. The influence of the Tween 80 concentration (0.025, 0.05, 0.1, 0.2, 0.5 and 1.0wt%) and solidification temperature (5 and 25°C) on the characteristics and stability of the NLC were investigated. The results showed that an increase in the Tween 80 concentration caused decreased zeta-potential (ζ-potential) and particle size (Z-average) with no significant effect on the polydispersity index (PDI). Lipid particles in the NLC at all Tween 80 concentrations had a tendency to grow and the PDI tended to increase due to Ostwald ripening upon storage over 28days. At least 0.2wt% Tween 80 concentrations could be used to stabilize 1wt% rambutan NLC. The solidification temperature affected the microstructure, melting behavior and stability of rambutan NLC. Pre-solidification at 5°C could create stable NLC with monodispersed-spherical lipid particles. Consequently, these stable NLC particles produced from rambutan kernel fat may serve as useful carriers for the delivery of bioactive lipophilic nutraceuticals. Copyright © 2017 Elsevier Inc. All rights reserved.

Phytotoxicity of citric acid and Tween® 80 for potential use as soil amendments in enhanced phytoremediation.

PubMed

Agnello, A C; Huguenot, D; van Hullebusch, E D; Esposito, G

2015-01-01

Enhanced phytoremediation adding biodegradable amendments like low molecular weight organic acids and surfactants is an interesting area of current research to overcome the limitation that represents low bioavailability of pollutants in soils. However, prior to their use in assisted phytoremediation, it is necessary to test if amendments per se exert any toxic effect to plants and to optimize their application mode. In this context, the present study assessed the effects of citric acid and Tween® 80 (polyethylene glycol sorbitan monooleate) on the development of alfalfa (Medicago sativa) plants, as influenced by their concentration and frequency of application, in order to evaluate the feasibility for their future use in enhanced phytoremediation of multi-contaminated soils. The results showed that citric acid negatively affected plant germination, while it did not have any significant effect on biomass or chlorophyll content. In turn, Tween® 80 did not affect plant germination and showed a trend to increase biomass, as well as it did not have any significant effect on chlorophyll levels. M. sativa appeared to tolerate citric acid and Tween® 80 at the tested concentrations, applied weekly. Consequently, citric acid and Tween® 80 could potentially be utilized to assist phytoremediation of contaminated soils vegetated with M. sativa.

Enzyme-linked immunosorbent assay for a soluble antigen of Renibacterium salmoninarum, the causative agent for salmonid bacterial kidney disease

USGS Publications Warehouse

Pascho, R.J.; Mulcahy, D.

1987-01-01

A double-antibody enzyme-linked immunosorbent assay (ELISA) for detection of a soluble fraction of Renibacterium salmoninarum was developed from components extracted from the supernatant of an R. salmoninarum broth culture. The Costar® Serocluster™ EIA microplate gave the highest absorbance and signal-to-noise ratios among seven types tested. Including Tween 80 in the wash buffer resulted in higher absorbances than Tween 20 when antigen was present. Background absorbance did not increase when Tween 80 was added to the wash buffer, but did when Tween 80 replaced Tween 20 in antigen and conjugate diluents. Adsorption of coating antibody peaked within 4 h at 37 °C and 16 h at 4 °C. Antigen attachment to antibody-coated microplate wells depended more on incubation temperature than duration; we adopted a 3-h incubation at 25 °C. Conjugate incubation for longer than 1 h at 37 °C or 3 h at 25 °C resulted in unacceptable background levels. No cross-reactions resulted from heat-extracted antigens of 10 other species of bacteria. The optimized ELISA is a 6-h test that enables detection of levels of soluble antigen as low as 2–20 ng.

Experimenting with Detergents

ERIC Educational Resources Information Center

Mitchell, Gail; Phillips, Donald B.

1977-01-01

Lists materials and procedures for experimenting with detergents. Included are methods for determination of the densities of dry detergents, ph values of detergent solutions, and a discussion of the ability of detergents to remove iodine stains from cloth. (CS)

Switchable solvents and methods of use thereof

DOEpatents

Jessop, Philip G.; Eckert, Charles A.; Liotta, Charles L.; Heldebrant, David J.

2013-08-20

A solvent that reversibly converts from a nonionic liquid mixture to an ionic liquid upon contact with a selected trigger, e.g., contact with CO.sub.2, is described. In preferred embodiments, the ionic solvent is readily converted back to the nonionic liquid mixture. The nonionic liquid mixture includes an amidine or guanidine or both, and water, alcohol, or a combination thereof. Single component amine solvents that reversibly convert between ionic and non-ionic states are also described. Some embodiments require increased pressure to convert; others convert at 1 atmosphere.

Switchable solvents and methods of use thereof

DOEpatents

Jessop, Philip G [Kingston, CA; Eckert, Charles A [Atlanta, GA; Liotta, Charles L [Atlanta, GA; Heldebrant, David J [Richland, WA

2011-07-19

A solvent that reversibly converts from a nonionic liquid mixture to an ionic liquid upon contact with a selected trigger, e.g., contact with CO.sub.2, is described. In preferred embodiments, the ionic solvent is readily converted back to the nonionic liquid mixture. The nonionic liquid mixture includes an amidine or guanidine or both, and water, alcohol, or a combination thereof. Single component amine solvents that reversibly convert between ionic and non-ionic states are also described. Some embodiments require increased pressure to convert; others convert at 1 atmosphere.

Switchable solvents and methods of use thereof

DOEpatents

Jessop, Philip G; Eckert, Charles A; Liotta, Charles L; Heldebrant, David J

2014-04-29

A solvent that reversibly converts from a nonionic liquid mixture to an ionic liquid upon contact with a selected trigger, e.g., contact with CO.sub.2, is described. In preferred embodiments, the ionic solvent is readily converted back to the nonionic liquid mixture. The nonionic liquid mixture includes an amidine or guanidine or both, and water, alcohol, or a combination thereof. Single component amine solvents that reversibly convert between ionic and non-ionic states are also described. Some embodiments require increased pressure to convert; others convert at 1 atmosphere.

New Tween-80 microbiological assay of serum folate levels in humans and animals.

PubMed

Zhou, Zhenghua; Yang, Yuan; Li, Ming; Kou, Chong; Xiao, Ping; Jiang, Yan; Hong, Junrong; Huang, Chengyu

2012-01-01

The objective of this study was to develop a new Tween-80 microbiological assay (Tween-80 MBA) to determine human or animal serum folate levels and to verify its reliability. The effects of the Lactobacillius casei subspecies rhamnosus (L. casei, ATCC No. 7469) inoculum concentration, incubation time, and Tween-80 on L. casei growth were studied, and the serum folate levels were investigated. Serum samples were collected from patients with esophageal cancer (EC) and healthy control subjects in Yanting, healthy adult subjects in Chengdu, Sichuan, and in male Sprague-Dawley rats. Optimal conditions for the new MBA were as follows: 1.28 x 10(7) CFU/mL working inoculum, vitamin folic acid assay broth with 0.24% (w/w) Tween-80, and anaerobic incubation with L. casei at 37 degrees C for 22 h. Under the optimal conditions, the working curve was in simple linear rather than logarithmic equation; the linear working curve of the folic acid standard working solution concentration versus the turbidity (adsorption value) of medium with L. casei ranged from 0.05 to 1.00 microg/L; the linear correlation coefficient was 0.9989 (SD 0.0007); the recovery rate of folate was 105.4-112.7%; and the minimum concentration for detecting folate was 0.03 microg/L. The RSD within-day and between-day precisions were 5.6 and 3.3%, respectively. The serum folate level of 100 EC patients was 6.4 (SEM 0.4) microg/L which was significantly lower than that of healthy control subjects [8.0 (SEM 0.6) microg/L, n = 100, P=0.020]. The new Tween-80 MBA is considered to be a reliable method for measuring serum folate level.

Brain targeted oral delivery of doxycycline hydrochloride encapsulated Tween 80 coated chitosan nanoparticles against ketamine induced psychosis: behavioral, biochemical, neurochemical and histological alterations in mice.

PubMed

Yadav, Monu; Parle, Milind; Sharma, Nidhi; Dhingra, Sameer; Raina, Neha; Jindal, Deepak Kumar

2017-11-01

To develop statistically optimized brain targeted Tween 80 coated chitosan nanoparticulate formulation for oral delivery of doxycycline hydrochloride for the treatment of psychosis and to evaluate its protective effect on ketamine induced behavioral, biochemical, neurochemical and histological alterations in mice. 3 2 full factorial design was used to optimize the nanoparticulate formulation to minimize particle size and maximize entrapment efficiency, while independent variables chosen were concentration of chitosan and Tween 80. The optimized formulation was characterized by particle size, drug entrapment efficiency, Fourier transform infrared, Transmission electron microscopy analysis and drug release behavior. Pure doxycycline hydrochloride (25 and 50 mg/kg, p.o.) and optimized doxycycline hydrochloride encapsulated Tween 80 coated chitosan nanoparticles (DCNP opt ) (equivalent to 25 mg/kg doxycycline hydrochloride, p.o.) were explored against ketamine induced psychosis in mice. The experimental studies for DCNP opt , with mean particle size 237 nm and entrapment efficiency 78.16%, elucidated that the formulation successfully passed through blood brain barrier and exhibited significant antipsychotic activity. The underlying mechanism of action was further confirmed by behavioral, biochemical, neurochemical estimations and histopathological study. Significantly enhanced GABA and GSH level and diminished MDA, TNF-α and dopamine levels were observed after administration of DCNP opt at just half the dose of pure doxycycline hydrochloride, showing better penetration of doxycyline hydrochloride in the form of Tween 80 coated nanoparticles through blood brain barrier. This study demonstrates the hydrophilic drug doxycycline hydrochloride, loaded in Tween 80 coated chitosan nanoparticles, can be effectively brain targeted through oral delivery and therefore represents a suitable approach for the treatment of psychotic symptoms.

Movement and fate of detergents in groundwater: a field study

USGS Publications Warehouse

Thurman, E.M.; Barber, L.B.; LeBlanc, D.

1986-01-01

The major cations, anions, and detergents in a plume of contaminated groundwater at Otis Air Base on Cape Cod (Mass., U.S.A.) have moved approximately 3.5 km down gradient from the disposal beds. We hypothesize that the detergents form two distinct plumes, which consist of alkyl benzene sulfonates (ABS) detergents and linear alkyl sulfonates (LAS) and sodium dodecyl sulfate (NaLS) detergents. The ABS detergents were deposited from approximately 1940 through 1965, when ABS detergents were banned. From 1965 to the present, LAS and NaLS detergents were in the sewage. The ABS detergents appear to be transported in the aquifer at the same rate as the specific conductance (major cations and anions) and boron, which are currently used as conservative tracers of the plume of contaminated groundwater. There appears to be little or no biological degradation of the ABS detergents in the aquifer, based on their concentration in the plume. On the other hand, the LAS and NaLS detergents have degraded rapidly and have been detected only 0.6 km down gradient. The roleof the detergents in the transport of other organic compounds in the plume is nuclear. There is a separation of the ABS detergent plume and the volatile organic compound plume; however, the time of entry of the detergents and the volatile organic compounds is unknown. Therefore, it is not possible to conclude on the interaction of these two classes of compounds. ?? 1986.

Design of experiments reveals critical parameters for pilot-scale freeze-and-thaw processing of L-lactic dehydrogenase.

PubMed

Roessl, Ulrich; Humi, Sebastian; Leitgeb, Stefan; Nidetzky, Bernd

2015-09-01

Freezing constitutes an important unit operation of biotechnological protein production. Effects of freeze-and-thaw (F/T) process parameters on stability and other quality attributes of the protein product are usually not well understood. Here a design of experiments (DoE) approach was used to characterize the F/T behavior of L-lactic dehydrogenase (LDH) in a 700-mL pilot-scale freeze container equipped with internal temperature and pH probes. In 24-hour experiments, target temperature between -10 and -38°C most strongly affected LDH stability whereby enzyme activity was retained best at the highest temperature of -10°C. Cooling profile and liquid fill volume also had significant effects on LDH stability and affected the protein aggregation significantly. Parameters of the thawing phase had a comparably small effect on LDH stability. Experiments in which the standard sodium phosphate buffer was exchanged by Tris-HCl and the non-ionic surfactant Tween 80 was added to the protein solution showed that pH shift during freezing and protein surface exposure were the main factors responsible for LDH instability at the lower freeze temperatures. Collectively, evidence is presented that supports the use of DoE-based systematic analysis at pilot scale in the identification of F/T process parameters critical for protein stability and in the development of suitable process control strategies. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication, characterisation and stability of oil-in-water emulsions stabilised by solid lipid particles: the role of particle characteristics and emulsion microstructure upon Pickering functionality.

PubMed

Zafeiri, I; Smith, P; Norton, I T; Spyropoulos, F

2017-07-19

The quest to identify and use bio-based particles with a Pickering stabilisation potential for food applications has lately been particularly substantial and includes, among other candidates, lipid-based particles. The present study investigates the ability of solid lipid particles to stabilise oil-in-water (o/w) emulsions against coalescence. Results obtained showed that emulsion stability could be achieved when low amounts (0.8 wt/wt%) of a surface active species (e.g. Tween 80 or NaCas) were used in particles' fabrication. Triple staining of the o/w emulsions enabled the visualisation of emulsion droplets' surface via confocal microscopy. This revealed an interfacial location of the lipid particles, hence confirming stabilisation via a Pickering mechanism. Emulsion droplet size was controlled by varying several formulation parameters, such as the type of the lipid and surface active component, the processing route and the polarity of the dispersed phase. Differential scanning calorimetry (DSC) was employed as the analytical tool to quantify the amount of crystalline material available to stabilise the emulsion droplets at different intervals during the experimental timeframe. Dissolution of lipid particles in the oil phase was observed and evolved distinctly between a wax and a triglyceride, and in the presence of a non-ionic surfactant and a protein. Yet, this behaviour did not result in emulsion destabilisation. Moreover, emulsion's thermal stability was found to be determined by the behaviour of lipid particles under temperature effects.

Formulation of vitamin D encapsulated cinnamon oil nanoemulsion: Its potential anti-cancerous activity in human alveolar carcinoma cells.

PubMed

Meghani, Nikita; Patel, Pal; Kansara, Krupa; Ranjan, Shivendu; Dasgupta, Nandita; Ramalingam, Chidambaram; Kumar, Ashutosh

2018-06-01

Cinnamon oil is used for medicinal purpose since ancient time because of its antioxidant activity. Oil-in-water nanoemulsion (NE) of cinnamon oil was formulated using cinnamon oil, nonionic surfactant Tween 80 and water by ultrasonication technique. Phase diagram was constructed to investigate the influence of oil, water and surfactant concentration. Vitamin D encapsulated cinnamon oil NE was fabricated by wash out method followed by ultrasonication in similar fashion. The hydrodynamic size of cinnamon oil NE and vitamin D encapsulated cinnamon oil NE was observed as 40.52 and 48.96 nm in complete DMEM F12 media respectively. We focused on the cytotoxic and genotoxic responses of NEs in A549 cells in concentration dependent manner. We observed that both NEs induce DNA damage along with corresponding increase in micronucleus frequency that is evident from the comet and CBMN assay. Both the NEs arrested the cell cycle progression in G0/G1 phase, showed increased expression of Bax, capase-3 and caspase-9 and decrease expression of BcL2 proteins along with significant (p < 0.05) increase in apoptotic cell population and loss of mitochondrial membrane potential. NEs were also evaluated for bactericidal efficacy against E. coli. Thus, both NEs have cytotoxic, genotoxic and antibacterial potential and hence can also be used in food industry with cinnamon oil as carrier for lipophilic nutraceutical like vitamin D. Copyright © 2018 Elsevier B.V. All rights reserved.

Preparation, Optimization, In vitro Evaluation and Ex vivo Permeation Studies of Finasteride loaded gel Formulations Prepared by using Response Surface Methodology.

PubMed

Khan, Muhammad Zia Ullah; Makreski, Petre; Murtaza, Ghulam

2018-05-02

The aim of present explorative study was to prepare and optimize finasteride loaded topical gel formulations by using three factor [propylene glycol (PG), Tween® 80, and sodium lauryl sulphate (SLS)], five level central composite design. Optimized finasteride topical gel formulation (F4), containing PG, Tween® 80, and SLS in a concentration of 0.8 mg, 0.4 mg and 0.2 mg, respectively, showed 6-fold higher values of cumulative drug release, flux, partition coefficient, input rate, lag time, and diffusion coefficient, when compared to control formulation without permeation enhancer. Finally, it can be concluded that finasteride permeation was enhanced by PG, tween® 80 and SLS individually, while in combination only PG along with tween® 80 had synergistic and more pronounced effect on flux, permeability coefficient and input rate while antagonistic effect on lag time and diffusion coefficient was observed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Enhancing oral bioavailability using preparations of apigenin-loaded W/O/W emulsions: In vitro and in vivo evaluations.

PubMed

Kim, Bum-Keun; Cho, Ah-Ra; Park, Dong-June

2016-09-01

We analyzed the physical properties and digestibility of apigenin-loaded emulsions as they passed through a simulated digestion model. As the emulsion passed through the simulated stages of digestion, the particle size and zeta potential of all the samples changed, except for the soybean oil-Tween 80 emulsion, in which zeta potential remained constant, through all stages, indicating that soybean oil-Tween 80 emulsions may have an effect on stability during all stages of digestion. Fluorescence microscopy was used to observe the morphology of the emulsions at each step. The in vivo pharmacokinetics revealed that apigenin-loaded soybean oil-Tween 80 emulsions had a higher oral bioavailability than did the orally administrated apigenin suspensions. These results suggest that W/O/W multiple emulsions formulated with soybean oil and tween 80 have great potential as targeted delivery systems for apigenin, and may enhance in vitro and in vivo bioavailability when they pass through the digestive tract. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of diacylglycerol production by glycerolysis of fish oil catalyzed by Lipozyme TL IM with Tween 65.

PubMed

Monte Blanco, S F M; Santos, J S; Feltes, M M C; Dors, G; Licodiedoff, S; Lerin, L A; de Oliveira, D; Ninow, J L; Furigo, A

2015-12-01

The diacylglycerols (DAG) are emulsifiers with high added value used as functional additives in food, medicine, and cosmetic industries. In glycerolysis of oils for the production of DAG, the immiscibility between the substrates (glycerol and oil phases) has to be overcome, for example, by the addition of a food grade surfactant like Tween 65. The main objective of this work was to optimize the process conditions for obtaining diacylglycerols rich in the omega-3 eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, through the enzymatic glycerolysis of fish oil, in systems with Tween 65 and without this surfactant, using Lipozyme TL(®) IM as biocatalyst. The experiments were performed according to predetermined conditions varying the temperature, enzyme load, the oil to glycerol molar ratio and, when added, the surfactant load. After 6 h of reaction, it was possible to produce up to 20.76 and 13.76% of diacylglycerols from fish oil in the reactions with and without Tween 65, respectively.

Morphological identification of Candida species on glucose agar, rice extract agar and corn meal agar with and without Tween-80.

PubMed

Joshi, K R; Solanki, A; Prakash, P

1993-01-01

A comparative study for the identification of 32 known strains of Candida species on the basis of morphology on glucose agar, rice extract agar and corn meal agar with and without Tween 80 revealed that when Tween 80 is incorporated in the media identification is possible for 96.8% of the species within 48 hours on rice extract agar and for 96.8% of the species within 48 hours on rice extract agar and for 90.6% of the species on glucose agar. The germ tubes and chlamydospores were also produced more on rice extract agar than on 0.1% glucose agar. Rice extract agar with Tween 80 can be used as single medium for morphologic identification of Candida species. The inoculated medium is first incubated at 37 degrees C for 3 hours and examined for germ tube formation and then incubated at 25 degrees C for 24 to 72 hours and examined for appearance of chlamydospores and mycelial morphology.

Enhanced cellulase hydrolysis of eucalyptus waste fibers from pulp mill by Tween80-assisted ferric chloride pretreatment.

PubMed

Chen, Liheng; Fu, Shiyu

2013-04-03

Pretreatment combining FeCl3 and Tween80 was performed for cellulose-to-ethanol conversion of eucalyptus alkaline peroxide mechanical pulping waste fibers (EAWFs). The FeCl3 pretreatment alone showed a good effect on the enzymatic hydrolysis of EAWFs, but inhibited enzyme activity to some extent. A surfactant, Tween80, added during FeCl3 pretreatment was shown to significantly enhance enzyme reaction by eluting enzymatic inhibitors such as iron(III) that are present at the surface of the pretreated biomass. Treatment temperature, liquid-solid ratio, treatment time, FeCl3 concentration, and Tween80 dosage for pretreatment were optimized as follows: 180 °C, 8:1, 30 min, 0.15 mol/L, and 1% (w/v). Pretreated EAWFs under such optimal conditions provided enzymatic glucose (based on 100 g of oven-dried feedstock) and substrate enzymatic digestibility of EAWFs of 34.8 g and 91.3% after 72 h of enzymatic hydrolysis, respectively, with an initial cellulase loading of 20 FPU/g substrate.

Ionizing and Nonionizing Radiation Protection. Module SH-35. Safety and Health.

ERIC Educational Resources Information Center

Center for Occupational Research and Development, Inc., Waco, TX.

This student module on ionizing and nonionizing radiation protection is one of 50 modules concerned with job safety and health. This module describes various types of ionizing and nonionizing radiation, and the situations in the workplace where potential hazards from radiation may exist. Following the introduction, 13 objectives (each keyed to a…

Interaction of two diclofenac acid salts with copolymers of ammoniomethacrylate: effect of additives and release profiles.

PubMed

Khalil, E; Sallam, A

1999-04-01

The copolymer of ammoniomethacrylate Eudragit RL (ERL) interacted with diclofenac acid salts (sodium and diethylamine salts) in aqueous solutions, forming a complex. Sorption experiments were done in aqueous solutions of either sodium lauryl sulfate (SLS), Tween 20, or Tween 80. The SLS competed strongly with the drug, even at low concentrations, and reduced significantly the amount of drug sorbed by ERL. Tweens at high concentrations exhibited two phase profiles: the sorption phase, which was short and during which drug concentration dropped sharply, and the release phase, during which the drug was released slowly over 24 hr and which was accompanied by dispersion of ERL particles into the colloidal dispersion. The interaction was dependent on temperature, ionic strength, and nature of the additives. The extent of interaction in water and phosphate buffer solutions was in the following order: water > pH 6 > pH 7-8. In-vitro dissolution studies of the dried complex were done over 24 hr. In water, the drug remained bound to the polymer. In aqueous surfactant solutions (SLS, Tween 20, and Tween 80) and phosphate buffer at pH 6.8, a linear relationship between drug concentration and the square root of time was obtained, indicating a matrix diffusion-controlled mechanism. However, 100% release was not reached, and resorption was observed in the phosphate buffer solution.

Tweens at risk: examining car safety practices in four economically disadvantaged urban elementary schools in Virginia.

PubMed

Will, Kelli England; Dunaway, Krystall E; Lorek, Edward J

2013-09-01

Children aged 8- to 12-years-old ("tweens") are at high risk for crash injury, and motor vehicle crashes are their leading cause of death. Data are presented from behavioral observations (N=243), surveys (N=677), and focus groups (N=26) conducted with tweens attending four urban elementary schools in Virginia. The populations assessed were predominantly black (77.9%) and economically disadvantaged (61.9%). Focus groups revealed a number of inconsistencies in and misconceptions about safety practices. Among the 677 tweens who completed anonymous surveys, the majority (58.1%) reported wearing their seat belts "not very much at all" or "never." Many students (47.8%) reported usually sitting in the front seat or sitting in the front and back seats equally. This is despite the fact that most (92.0%) knew that the back seat was the safest place to sit. Of the 243 tweens observed in vehicles, 65.0% were unrestrained and 60.1% were seated in the front passenger seat. Findings of this study shed light on the great disparity between the national rates for child safety practices and those of children living in an economically disadvantaged urban school district. Additional intervention programs that are culturally appropriate and specifically target this age group are needed. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.

Determination of tannic acid in industrial wastewater based on chemiluminescence system of KIO₄-H₂O₂-Tween40.

PubMed

Xie, Cheng-gen; Li, Huai-fen

2010-01-01

The oxidation reaction of H₂O₂ with KIO₄ can produce chemiluminescence (CL) in the presence of the surfactant Tween40 and the CL intensity of the CL system KIO₄-H₂O₂-Tween40 can be strikingly enhanced after injection of tannic acid. On this basis, a flow injection method with CL detection was established for the determination of tannic acid. The method is simple, rapid and effective to determine tannic acid in the range of 7.0 × 10(-9) to 1.0 × 10(-5) mol/L with a determination limit of 2.3 × 10(-9) mol/L. The relative standard deviation is 2.6% for the determination of 5.0 × 10(-6 )mol/L tannic acid (n = 11). The method has been applied to determine the content of tannic acid in industrial wastewater with satisfactory results. It is believed that the CL reaction formed singlet oxygen (1)O(2)* and the emission was from an excited oxygen molecular pair O₂(¹Δ(g))O₂(¹∑⁻(g)) in the KIO₄-H₂O₂-Tween40 reaction. Tween40 played an important role in enhancing stabilization of the excited oxygen molecular pair O₂(¹Δ(g))O₂(¹∑⁻(g)) and in increasing CL intensity. Copyright © 2010 John Wiley & Sons, Ltd.

Application of polyhydroxyalkanoate binding protein PhaP as a bio-surfactant.

PubMed

Wei, Dai-Xu; Chen, Chong-Bo; Fang, Guo; Li, Shi-Yan; Chen, Guo-Qiang

2011-08-01

PhaP or phasin is an amphiphilic protein located on surfaces of microbial storage polyhydroxyalkanoates granules. This study aimed to explore amphiphilic properties of PhaP for possible application as a protein surfactant. Following agents were used to conduct this study as controls including bovine serum albumin, sodium dodecyl sulfate (SDS), Tween 20, sodium oleate, a commercial liquefied detergent together with the same amount of PhaP. Among all these tested control surfactants, PhaP showed the strongest effect to form emulsions with lubricating oil, diesel, and soybean oil, respectively. PhaP emulsion stability study compared with SDS revealed that PhaP had a stronger capability to maintain a very stable emulsion layer after 30 days while SDS lost half and two-thirds of its capacity after 2 and 30 days, respectively. When PhaP was more than 200 μg/ml in the water, all liquids started to exhibit stable emulsion layers. Similar to SDS, PhaP significantly reduced the water contact angles of water on a hydrophobic film of biaxially oriented polypropylene. PhaP was thermally very stable, it showed ability to form emulsion and to bind to the surface of polyhydroxybutyrate nanoparticles after a 60- min heating process at 95 °C. It is therefore concluded that PhaP is a protein with thermally stable property for application as natural and environmentally friendly surfactant for food, cosmetic, and pharmaceutical usages.

Electron microscopic observations of mouse sperm whole mounts after extraction for nuclear matrix and intermediate filaments.

PubMed

Markova, M D

2001-01-01

Nuclear matrix and intermediate filaments (NM-IF) can be isolated by sequential treatment with non-ionic detergent, high salt. and nuclease. Extracted cells are easily observed by unembedded whole-mount transmission electron microscopy. Different somatic cell types have been subjected to this procedure and retained their essential architecture. To our knowledge, this work describes the first application of NM-IF extraction to sperm. After chemical dissection the general appearance of mouse sperm cells was preserved, except for head-from-neck separation in some cases. The cell membrane, acrosome and mitochondria were not present. The nucleus showed no apparent changes and revealed no details excepting pore complexes in the posterior part. Tissue-specific cytoskeletal elements (perforatorium, postacrosomal sheath, capitulum, segmented columns, outer dense fibers, submitochondrial reticulum, annulus, and fibrous sheath) were retained, which permitted a parallel between them and intermediate filaments of somatic cells. Tail microtubules were also relatively well preserved, showing high intrinsic stability. Cell structures could be observed well, with some details in the tail even better visible than in ultrathin sections. Observation of mouse sperm whole mounts after NM-IF extraction not only revealed intermediate filament-like properties of their cytoskeletal elements but also offered an additional viewpoint to sperm ultrastructure.

Spermicides 2002: an overview.

PubMed

Lech, M M

2002-09-01

The first-ever written prescription for a contraceptive (barrier method) tampon can be found in the Ebers Papyrus, a compendium of medical practices written in 1550 BC. Modern spermicides are produced in a variety of formulations, including gels, foams, creams, suppositories, pessaries, capsules, foaming tablets and films. Spermicides are relatively inexpensive and widely available over the counter. Most of the currently used spermicides contain the chemical agent (non-ionic detergent) nonoxynol-9. The spermicide 'as a commonly used method' has a very high failure rate (one pregnancy in every four women using this method of contraception for 1 year). Implementation of other, much more effective methods of contraception has made spermicides less and less popular, but recently their potential properties against HIV and STI pathogens (a cause of sexually transmitted diseases) have led to new attention for these products. These properties have been widely evaluated in clinical trials, but the final conclusion does not favor spermicides as the tool for the global fight against HIV/AIDS. There is an urgent need for the invention of a chemical product that, for dual protection, would be administered vaginally before sexual intercourse to kill HIV and other STI pathogens, and at the same time disable or kill sperm. The new era for barrier methods should begin from the development of novel microbicides.

Protein-surfactant interactions at hydrophobic interfaces studied with total internal reflection fluorescence correlation spectroscopy (TIR-FCS).

PubMed

Sonesson, Andreas W; Blom, Hans; Hassler, Kai; Elofsson, Ulla M; Callisen, Thomas H; Widengren, Jerker; Brismar, Hjalmar

2008-01-15

The aim of this work was to study the dynamics of proteins near solid surfaces in the presence or absence of competing surfactants by means of total internal reflection fluorescence correlation spectroscopy (TIR-FCS). Two different proteins were studied, bovine serum albumin (BSA) and Thermomyces lanuginosus lipase (TLL). A nonionic/anionic (C12E6/LAS) surfactant composition was used to mimic a detergent formulation and the surfaces used were C18 terminated glass. It was found that with increasing surfactant concentrations the term in the autocorrelation function (ACF) representing surface binding decreased. This suggested that the proteins were competed off the hydrophobic surface by the surfactant. When fitting the measured ACF to a model for surface kinetics, it was seen that with raised C12E6/LAS concentration, the surface interaction rate increased for both proteins. Under these experimental conditions this meant that the time the protein was bound to the surface decreased. At 10 microM C12E6/LAS the surface interaction was not visible for BSA, whereas it was still distinguishable in the ACF for TLL. This indicated that TLL had a higher affinity than BSA for the C18 surface. The study showed that TIR-FCS provides a useful tool to quantify the surfactant effect on proteins adsorption.

Role of a reducing environment in disassembly of the herpesvirus tegument

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

Newcomb, William W.; Jones, Lisa M.; Dee, Alexander

2012-09-15

Initiation of infection by herpes family viruses involves a step in which most of the virus tegument becomes detached from the capsid. Detachment takes place in the host cell cytosol near the virus entry site and it is followed by dispersal of tegument proteins and disappearance of the tegument as a distinct entity. Here we describe the results of experiments designed to test the idea that the reducing environment of the cytosol may contribute to tegument detachment and disassembly. Non-ionic detergent was used to remove the membrane of purified herpes simplex virus under control and reducing conditions. The effects onmore » the tegument were then examined by SDS-PAGE and electron microscopy. Protein analysis demonstrated that most major tegument proteins were removed under both oxidizing and reducing conditions except for UL49 which required a reducing environment. It is proposed therefore that the reducing conditions in the cytosol are involved in removal of UL49 protein. Electron microscopic analysis revealed that capsids produced under oxidizing conditions contained a coating of protein that was absent in reduced virions and which correlated uniquely with the presence of UL49. This capsid-associated layer is suggested to be the location of UL49 in the extracted virion.« less

Toxicity and chemical analyses of airport runoff waters in Poland.

PubMed

Sulej, Anna Maria; Polkowska, Zaneta; Wolska, Lidia; Cieszynska, Monika; Namieśnik, Jacek

2014-05-01

The aim of this study was to assess the ecotoxicological effects of various compounds in complex airport effluents using a chemical and ecotoxicological integrated strategy. The present work deals with the determination of sum of PCBs, PAHs, pesticides, cations, anions, phenols, anionic, cationic, non-ionic detergents, formaldehyde and metals--as well as TOC and conductivity--in runoff water samples collected from 2009 to 2011 at several locations on two Polish international airports. Two microbiotests (Vibrio fischeri bacteria and the crustacean Thamnocephalus platyurus) have been used to determine the ecotoxicity of airport runoff waters. The levels of many compounds exceeded several or even several tens of times the maximum permissible levels. Analysis of the obtained data shows that samples that displayed maximum toxicity towards the bioindicators Vibrio fischeri were not toxic towards Thamnocephalus platyurus. Levels of toxicity towards T. platyurus are strongly correlated with pollutants that originate from the technological operations related to the maintenance of airport infrastructure. The integrated (chemical-ecotoxicological) approach to environmental contamination assessment in and around airports yields extensive information on the quality of the environment. These methodologies can be then used as tools for tracking the environmental fate of these compounds and for assessing the environmental effect of airports. Subsequently, these data will provide a basis for airport infrastructure management.

Preteen Girls, Magazines, and the Negotiation of Young Sexual Femininity

ERIC Educational Resources Information Center

Vares, Tiina; Jackson, Sue

2015-01-01

The focus on, and concern about, young girls and preteens or "tweens" relates to the "sexualisation" of girlhood and the notion that girls are "growing up too fast" and becoming "too sexy too soon". In both popular and academic accounts, "tween" magazines and the increasingly "sexualised"…

Refractive index-based determination of detergent concentration and its application to the study of membrane proteins

PubMed Central

Strop, Pavel; Brunger, Axel T.

2005-01-01

The concentration of detergent in membrane protein preparations can have a critical role on protein stability, function, and the potential for crystallization. Unfortunately, dialysis or protein concentration can lead to an unknown amount of detergent in the final membrane protein preparations. Here we present a method for the determination of detergent concentration based on refractive index of the detergent solution. This method was applied to quantitate the amount of detergent remaining in solution after concentration in various concentrators. We found that the ability of the tested detergents to pass through the molecular weight cutoff membrane correlates well with detergent micelle size. Therefore, the micelle size can be used as a rough guide to estimate the retention of a given detergent in various molecular weight cutoff concentrators. The refractive index method is exceptionally informative when coupled with size exclusion chromatography and light scattering, and can be used to determine the oligomeric state of the membrane protein, the size of a protein-associated micelle, as well as the amount and size of the unbound detergent micelle. PMID:16046633

Refractive index-based determination of detergent concentration and its application to the study of membrane proteins.

PubMed

Strop, Pavel; Brunger, Axel T

2005-08-01

The concentration of detergent in membrane protein preparations can have a critical role on protein stability, function, and the potential for crystallization. Unfortunately, dialysis or protein concentration can lead to an unknown amount of detergent in the final membrane protein preparations. Here we present a method for the determination of detergent concentration based on refractive index of the detergent solution. This method was applied to quantitate the amount of detergent remaining in solution after concentration in various concentrators. We found that the ability of the tested detergents to pass through the molecular weight cutoff membrane correlates well with detergent micelle size. Therefore, the micelle size can be used as a rough guide to estimate the retention of a given detergent in various molecular weight cutoff concentrators. The refractive index method is exceptionally informative when coupled with size exclusion chromatography and light scattering, and can be used to determine the oligomeric state of the membrane protein, the size of a protein-associated micelle, as well as the amount and size of the unbound detergent micelle.

Effects of Surfactant on the Transport of Toxoplasma gondii in Saturated Sandy Porous Media: Experimental Tests and Modeling

NASA Astrophysics Data System (ADS)

Darnault, C. J. G.; Mutty, T.; L'Ollivier, C.; Dubey, J. P.; Aurélien, D.; Pullano, C. P.

2017-12-01

Understanding the transport of pathogens in the subsurface environment is essential for the risk assessment of groundwater contamination and the potential threat to human health. Currently, there is a lack of research in particular concerning the fate and transport of Toxoplasma gondii in porous media. The purpose of this research will be to characterize and model the transport and retention of Toxoplasma gondii in saturated silica-sand porous media in the presence of surfactant. Surfactants are chemicals commonly used as detergents and soaps, however they are able to impact flow properties in porous media and the interactions between surfaces, such as oocysts walls with sand grains. Therefore, we chose to characterize the changes that two surfactants have on the transport and fate of T. gondii. A total of 14 Column experiments were conducted including replicates as follows: 6 columns with an anionic-surfactant solution, 6 with a nonionic-surfactant solution, and 2 columns without surfactant to act as controls. All of the columns contained fine sand as the dominant grain size and each was run with a specified saturated flow rate in order to analyze the change with surfactant and disregard change as a result of a variation in the pore velocity. We chose to determine the retention and flow using the classic clean-bed colloid filtration model, and implemented sources for both adsorption and desorption of the particles which is known to happen on other biocolloids including oocysts. We implemented both Linear alkylbenzene sulphonic acid and Alkylphenol ethoxylate as our surfactants since they are the anionic and nonionic surfactants most commonly found in wastewater. Three different Critical Micelle Concentrations (CMC's) were run through the columns prior to the T. gondii oocysts injection followed by sequential injection of surfactant only and then deionized water only. The study compares the breakthrough of T. gondii with surfactant, without surfactant, as well as a the breakthrough of a bromide tracer. Each approach was modeled in addition to the experimentaltesting and we compared our results to previous microbe transport studies.

[Evaluation of the mutagenicity of detergents by tests on bacteria, plant cells and human leucocytes.].

PubMed

Feretti, Donatella; Pedrazzani, Roberta; Ceretti, Elisabetta; Zerbini, Ilaria; Gozio, Eleonora; Belotti, Caterina; Alias, Carlotta; Donato, Francesco; Gelatti, Umberto

2009-01-01

The aim of this study was to evaluate the mutagenicity of several traditional detergents and that of newer more biodegradable detergents, by using a bacterial test (Ames test), a plant cell test (Allium cepa micronuclei test) and a human leucocyte test (Comet test). All tests were conducted using a wide range of doses (1-2000 mg/l). None of the examined detergents induced mutations in S.typhimurium. One traditional detergent showed a genotoxic effect with the A. cepa test, while all newer detergents and one traditional detergent were shown by the Comet test to be capable of inducing DNA damage.

Detergents compared with each other and with antiseptics as skin 'degerming' agents.

PubMed Central

Lilly, H. A.; Lowbury, E. J.; Wilkins, M. D.

1979-01-01

Three detergent preparations (bar soap, 'Hibiscrub' base and 'LIC 76'), TWO ANTISEPTic preparations (0.5% chlorhexidine in 95% ethyl alcohol and an alcohol jelly, 'Alcogel'), and one antiseptic-detergent solution (4% chlorhexidine gluconate in a detergent base, 'Hibiscrub') were compared for their effectiveness, on a single use, in reducing the yield of bacteria from the hands of volunteers. The antiseptic and antiseptic--detergent preparations were more effective than the detergents, with a mean reduction in yield of skin bacteria of 96.0% after use of alcoholic chlorhexidine and of 81.2% after use of Hibiscrub. One of the detergents, LIC 76, appeared more effective than the others, causing a mean reduction in the yield of skin bacteria of 41.5%, compared with reductions of 4.6% by the Hibiscrub detergent base and an increase of 3.2% with bar soap; unlike the other detergents, LIC 76 was found to have appreciable bacteristatic and bactericidal properties. PMID:762408

Multicultural Programs for Tweens and Teens

ERIC Educational Resources Information Center

Alexander, Linda B., Ed.; Kwon, Nahyun, Ed.

2010-01-01

"Multicultural Programs for Tweens and Teens" is a one-stop resource that encourages children and young adults to explore different cultures. Dozens of flexible programming ideas allow you to: (1) Choose a program specific to your scheduling, budget, or age group requirements; (2) Create an event that reflects a specific culture; and (3) Recommend…

Blogging and Tweens: Communication Portal to Reading Selection and Engagement

ERIC Educational Resources Information Center

Sharber, Shelli K.

2012-01-01

The ethnographic study utilized the research techniques of observations, content analysis, and semi-structured interviews with tween participants (i.e., 9- through 13-year-old youth) during an 8-week literary blog project. Twenty-six participants created individual blog pages within a member-only classroom blog site that allowed for online…

Promoting physical activity among youth through community-based prevention marketing.

PubMed

Bryant, Carol A; Courtney, Anita H; McDermott, Robert J; Alfonso, Moya L; Baldwin, Julie A; Nickelson, Jen; McCormack Brown, Kelli R; Debate, Rita D; Phillips, Leah M; Thompson, Zachary; Zhu, Yiliang

2010-05-01

Community-based prevention marketing (CBPM) is a program planning framework that blends community-organizing principles with a social marketing mind-set to design, implement, and evaluate public health interventions. A community coalition used CBPM to create a physical activity promotion program for tweens (youth 9-13 years of age) called VERB Summer Scorecard. Based on the national VERB media campaign, the program offered opportunities for tweens to try new types of physical activity during the summer months. The VERB Summer Scorecard was implemented and monitored between 2004 and 2007 using the 9-step CBPM framework. Program performance was assessed through in-depth interviews and a school-based survey of youth. The CBPM process and principles used by school and community personnel to promote physical activity among tweens are presented. Observed declines may become less steep if school officials adopt a marketing mind-set to encourage youth physical activity: deemphasizing health benefits but promoting activity as something fun that fosters spending time with friends while trying and mastering new skills. Community-based programs can augment and provide continuity to school-based prevention programs to increase physical activity among tweens.

Microemulsions based on a sunflower lecithin-Tween 20 blend have high capacity for dissolving peppermint oil and stabilizing coenzyme Q10.

PubMed

Chen, Huaiqiong; Guan, Yongguang; Zhong, Qixin

2015-01-28

The objectives of the present study were to improve the capability of microemulsions to dissolve peppermint oil by blending sunflower lecithin with Tween 20 and to study the possibility of codelivering lipophilic bioactive compounds. The oil loading in microemulsions with 20% (w/w) Tween 20 increased from 3% (w/w) to 20% (w/w) upon gradual supplementation of 6% (w/w) lecithin. All microemulsions had particles of <12 nm that did not change over 70 d of storage at 21 °C. They had relatively low Newtonian viscosities and were physically and chemically stable after 50-200-fold dilution in water, resulting from similar hydrophile-lipophile-balance values of the surfactant mixture and peppermint oil. Furthermore, the microemulsions were capable of dissolving coenzyme Q10 and preventing its degradation at UV 302 nm, more significant for the microemulsion with lecithin. Therefore, natural surfactant lecithin can reduce the use of synthetic Tween 20 to dissolve peppermint oil and protect the degradation of dissolved lipophilic bioactive components in transparent products.

Diluents for stabilization of tuberculin

PubMed Central

Magnusson, Mogens; Guld, Johannes; Magnus, Knut; Waaler, Hans

1958-01-01

Tuberculin is known to be adsorbed to containers and syringes. In the present paper, the adsorption which takes place in the ampoules has been studied in relation to the diluent for the tuberculin. Adsorption was most evident in dilutions prepared with saline or with phosphate buffer containing dextran. The inclusion in phosphate buffer diluent of small amounts of proteins or synthetic surface-active agents decreased or prevented adsorption. A boric-acid sodium-borate diluent containing gum arabic, previously recommended for the preparation of stabilized tuberculin dilutions, was found to be ineffective. The most suitable diluent for the preparation of stable tuberculin dilutions was a 0.05‰ solution of Tween 80 in phosphate-buffered saline; this diluent appeared to prevent adsorption under a variety of experimental conditions. The inclusion of Tween 80 in the diluent had little or no effect on the general storage stability of purified tuberculin. Sensitization experiments in guinea-pigs, rabbits and humans showed that no sensitization against Tween 80 need be feared when a 0.05‰ solution of Tween 80 in phosphate buffered saline is used in the preparation of tuberculin dilutions. PMID:13618720

Cabazitaxel-loaded human serum albumin nanoparticles as a therapeutic agent against prostate cancer

PubMed Central

Qu, Na; Lee, Robert J; Sun, Yating; Cai, Guangsheng; Wang, Junyang; Wang, Mengqiao; Lu, Jiahui; Meng, Qingfan; Teng, Lirong; Wang, Di; Teng, Lesheng

2016-01-01

Cabazitaxel-loaded human serum albumin nanoparticles (Cbz-NPs) were synthesized to overcome vehicle-related toxicity of current clinical formulation of the drug based on Tween-80 (Cbz-Tween). A salting-out method was used for NP synthesis that avoids the use of chlorinated organic solvent and is simpler compared to the methods based on emulsion-solvent evaporation. Cbz-NPs had a narrow particle size distribution, suitable drug loading content (4.9%), and superior blood biocompatibility based on in vitro hemolysis assay. Blood circulation, tumor uptake, and antitumor activity of Cbz-NPs were assessed in prostatic cancer xenograft-bearing nude mice. Cbz-NPs exhibited prolonged blood circulation and greater accumulation of Cbz in tumors along with reduced toxicity compared to Cbz-Tween. Moreover, hematoxylin and eosin histopathological staining of organs revealed consistent results. The levels of blood urea nitrogen and serum creatinine in drug-treated mice showed that Cbz-NPs were less toxic than Cbz-Tween to the kidneys. In conclusion, Cbz-NPs provide a promising therapeutic for prostate cancer. PMID:27555767

Enhancing enzymatic hydrolysis of sugarcane bagasse by ferric chloride catalyzed organosolv pretreatment and Tween 80.

PubMed

Zhang, Hongdan; Fan, Meishan; Li, Xin; Zhang, Aiping; Xie, Jun

2018-06-01

In this work, a FeCl 3 -catalyzed organosolv pretreatment was employed at 160 °C to remove hemicellulose and lignin in sugarcane bagasse leaving the cellulose-enriched residue for enzymatic hydrolysis to sugars. The solubilized hemicellulose fractions consisted more monomer xylose than oligomer xylose. The FeCl 3 -catalyzed organosolv pretreatment significantly improved the enzymatic hydrolysis, nearly 100% of cellulose components were converted to glucose after pretreatment with 0.05 M FeCl 3 . Structural analysis was employed to reveal how pretreatment affected the enzymatic hydrolysis. With the addition of Tween 80, the same level of glucose was obtained with 50% reduction of enzyme dosage after 24 h. Furthermore, the influence of Tween 80 on different pretreatment systems was investigated, indicating that the improvement was increased as the lignin content increased, decreased with high enzyme loading and extending hydrolysis time. This work suggested that the addition of Tween 80 could improve the enzymatic hydrolysis, reduce the hydrolysis time and enzyme dosage. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effectiveness of dishwashing liquids in removing chlorothalonil and chlorpyrifos residues from cherry tomatoes.

PubMed

Wang, Zhiwei; Huang, Jiexun; Chen, Jinyuan; Li, Feili

2013-08-01

Washing is the most practical way to remove pesticide residues in fruits and vegetables. Two commonly used kitchen dishwashing liquids (detergents) in Chinese market were tested for enhanced removal of chlorpyrifos (CHP) and chlorothalonil (CHT) in cherry tomatoes by soaking the cherry tomatoes in the detergent solutions. The critical micelle concentrations of detergent A and detergent B were about 250 mg L(-1) and 444 mg L(-1), respectively. Detergent A had a higher solubilizing ability for pesticides and hence washing effectiveness than detergent B. The apparent solubility of CHP increased with increasing detergent concentration, while that of CHT remained comparatively invariant independent of detergent concentration within the tested range. The apparent solubility of CHP was also consistently higher in solutions of both detergents as compared to CHT. Due probably to its lower logKow value, CHT was more readily washed off cherry tomatoes than CHP. In terms of washing, a duration of 10-20 min was sufficient for removal of pesticides on cherry tomatoes in distilled water and detergent solutions. The effectiveness of removing pesticides increased with increasing detergent concentration from 50 mg L(-1) to 5 g L(-1), with up to 80% CHT and 42% CHP removed. Multiple washing further increased pesticide removal. Adding 10% acetic acid to lower pH or increasing washing temperature favored pesticide removal, but 10% NaCl produced the shielding effect and substantially reduced the effectiveness of detergent A for pesticide removal. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of chemicals on production, composition and antioxidant activity of polysaccharides of Inonotus obliquus.

PubMed

Xu, Xiangqun; Quan, Lili; Shen, Mengwei

2015-01-01

Polysaccharides are important secondary metabolites from the medicinal mushroom Inonotus obliquus. Various fatty acids, surfactants and organic solvents as cell membrane-reorganizing chemicals were investigated for their stimulatory effects on the growth of fungal mycelium and production of exopolysaccharides (EPS) and endopolysaccharides (IPS) by submerged fermentation of I. obliquus. After evaluation of 14 chemicals, oleic acid, Tween 80, and TritonX-100 were chosen for optimization of addition concentration and addition time. Among the three chemicals, 0.1% (v/v) Tween 80 gave maximum production of mycelial biomass, EPS, IPS1, and IPS2 with a increase of 16.6, 81.6, 37.7 and 18.1%, respectively, when supplemented at the early growth phase (24h after inoculation). These EPS, IPS1, and IPS2 had significantly (p<0.05) stronger scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals than those from the control medium. IPS1 from Tween 80-containing medium was the most effective antioxidant, with an estimated IC50 value of 0.74mg/mL. This might be attributed to that the EPS and IPS from the Tween 80-containing medium had significantly (p<0.05) higher content of sugar and glucose among the six monosaccharide compositions than those from the control. The simultaneously enhanced accumulation of bioactive EPS and IPS of cultured I. obliquus supplemented with Tween 80 was evident. Copyright © 2015 Elsevier B.V. All rights reserved.

Laundry detergents: an overview.

PubMed

Bajpai, Divya; Tyagi, V K

2007-01-01

Nowadays laundry detergents are becoming increasingly popular as they can be metered automatically into the washing machine, impart softness, antistaticness, resiliency to fabrics, mild to eyes and skins and shows good dispersibility in water. Because it is consumed when it is used, the sale of laundry detergent is a rather large business. There are many different kinds or brands of laundry detergent sold, many of them claiming some special qualities as selling points. A Laundry detergent composition is a formulated mixture of raw materials that can be classified into different types based on their properties and function in the final product. The different classes of raw materials are surfactants, builders, bleaching agents, enzymes, and minors which remove dirt, stain, and soil from surfaces or textiles gave them pleasant feel and odour. The physico-chemical properties of surfactants make them suitable for laundry purposes. Laundry detergent has traditionally been a powdered or granular solid, but the use of liquid laundry detergents has gradually increased over the years, and these days use of liquid detergent equals or even exceeds use of solid detergent. This review paper describes the history, composition, types, mechanism, consumption, environmental effects and consumption of laundry detergents.

Correlating Detergent Fiber Analysis and Dietary Fiber Analysis Data for Corn Stover

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

Wolfrum, E. J.; Lorenz, A. J.; deLeon, N.

There exist large amounts of detergent fiber analysis data [neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL)] for many different potential cellulosic ethanol feedstocks, since these techniques are widely used for the analysis of forages. Researchers working in the area of cellulosic ethanol are interested in the structural carbohydrates in a feedstock (principally glucan and xylan), which are typically determined by acid hydrolysis of the structural fraction after multiple extractions of the biomass. These so-called dietary fiber analysis methods are significantly more involved than detergent fiber analysis methods. The purpose of this study was to determinemore » whether it is feasible to correlate detergent fiber analysis values to glucan and xylan content determined by dietary fiber analysis methods for corn stover. In the detergent fiber analysis literature cellulose is often estimated as the difference between ADF and ADL, while hemicellulose is often estimated as the difference between NDF and ADF. Examination of a corn stover dataset containing both detergent fiber analysis data and dietary fiber analysis data predicted using near infrared spectroscopy shows that correlations between structural glucan measured using dietary fiber techniques and cellulose estimated using detergent techniques, and between structural xylan measured using dietary fiber techniques and hemicellulose estimated using detergent techniques are high, but are driven largely by the underlying correlation between total extractives measured by fiber analysis and NDF/ADF. That is, detergent analysis data is correlated to dietary fiber analysis data for structural carbohydrates, but only indirectly; the main correlation is between detergent analysis data and solvent extraction data produced during the dietary fiber analysis procedure.« less

Creating Drug Solubilization Compartments via Phase Separation in Multicomponent Buccal Patches Prepared by Direct Hot Melt Extrusion-Injection Molding.

PubMed

Alhijjaj, Muqdad; Bouman, Jacob; Wellner, Nikolaus; Belton, Peter; Qi, Sheng

2015-12-07

Creating in situ phase separation in solid dispersion based formulations to allow enhanced functionality of the dosage form, such as improving dissolution of poorly soluble model drug as well as being mucoadhesive, can significantly maximize the in vitro and in vivo performance of the dosage form. This formulation strategy can benefit a wide range of solid dosage forms for oral and alternative routes of delivery. This study using buccal patches as an example created separated phases in situ of the buccal patches by selecting the excipients with different miscibility with each other and the model drug. The quaternary dispersion based buccal patches containing PEG, PEO, Tween 80, and felodipine were prepared by direct hot melt extrusion-injection molding (HME-IM). The partial miscibility between Tween 80 and semicrystalline PEG-PEO led to the phase separation after extrusion. The Tween phases acted as drug solubilization compartments, and the PEG-PEO phase had the primary function of providing mucoadhesion and carrier controlled dissolution. As felodipine was preferably solubilized in the amorphous regions of PEG-PEO, the high crystallinity of PEG-PEO resulted in an overall low drug solubilizing capacity. Tween 80 was added to improve the solubilization capacity of the system as the model drug showed good solubility in Tween. Increasing the drug loading led to the supersaturation of drug in Tween compartments and crystalline drug dispersed in PEG-PEO phases. The spatial distribution of these phase-separated compartments was mapped using X-ray micro-CT, which revealed that the domain size and heterogeneity of the phase separation increased with increasing the drug loading. The outcome of this study provides new insights into the applicability of in situ formed phase separation as a formulation strategy for the delivery of poorly soluble drugs and demonstrated the basic principle of excipient selection for such technology.

Modification of crystal habit of ibuprofen using the phase partition technique: effect of aerosil and tween 80 in binding solvent.

PubMed

Umprayn, K; Luengtummuen, A; Kitiyadisai, C; Pornpiputsakul, T

2001-11-01

A ternary diagram, representing the solubility of binding solvent (chloroform) in a mixture of ethanol and water, was constructed. For this study, the solvent mixture that gave the best ibuprofen pellets (IPs) was composed of chloroform.ethanol:water at a ratio of 1.5%:8%:90.5%. The suitable agitator speed, temperature, and mixing time were found to be 1,500 rpm, 25 degrees C +/- 2 degrees C, and 20 min, respectively. In addition, suitable stirring time when the phase partition process of IPs began was 15 min. IPs obtained from these conditions were small and round, approximately 1 mm; surface determination by scanning electron microscopy (SEM) indicated that the IPs were composed of drug microcrystals rearranged on the surface. For the dissolution, IPs showed lower drug release when compared with pure ibuprofen crystal (IC) (f2 analysis). An attempt to modify the dissolution property of IP by incorporating various concentrations of Aerosil and Tween 80 in the binding solvent was made. Microscopic appearance showed that both Aerosil and Tween 80 gave less spherical pellets when compared with the use of binding solvent alone. For both the Aerosil and Tween 80 employed, the results indicated a change in rearrangement of drug microcrystals and a change in crystal habit. However, Tween 80 gave more change of the crystallographic direction of drug microcrystals than Aerosil. In term of dissolution, the results showed that employing Tween 80 at 1.2% gave the highest drug release compared to the use of Aerosil and IC alone (f2 analysis). These pellets had a good flow property, as indicated by Carr's compressibility, flow rate, and angle of repose, and they can be compressed into a tablet, encapsulated by suitable polymer, or pulverized to obtain micronized crystals. In the case of compression into tablets, the dissolution profiles of these tablets compared with those of commercial product meet the USP 24 requirement (Q > or = 80% at 60 min).

Harmful effect of detergents on lipase.

PubMed

Fatima, Sadaf; Ajmal, Rehan; Badr, Gamal; Khan, Rizwan H

2014-11-01

In order to study effects of detergents at molecular level, we have done activity measurements of wheat germ lipase in increasing concentration of some commercial detergents. Conformational changes in protein structure using circular dichroism and fluorescence spectroscopy were studied in increasing concentration of sodium dodecyl sulfate. Our study proves that detergents may lead to loss of enzymatic activity and structure of plant enzymes. Since detergents are common source of pollution in water bodies and the water from these resources can be used in fields, our study may prove helpful in creating awareness about harmful action of detergents.

Flow-induced immobilization of glucose oxidase in nonionic micellar nanogels for glucose sensing.

PubMed

Cardiel, Joshua J; Zhao, Ya; Tonggu, Lige; Wang, Liguo; Chung, Jae-Hyun; Shen, Amy Q

2014-10-21

A simple microfluidic platform was utilized to immobilize glucose oxidase (GOx) in a nonionic micellar scaffold. The immobilization of GOx was verified by using a combination of cryogenic electron microscopy (cryo-EM), scanning electron microscopy (SEM), and ultraviolet spectroscopy (UV) techniques. Chronoamperometric measurements were conducted on nanogel-GOx scaffolds under different glucose concentrations, exhibiting linear amperometric responses. Without impacting the lifetime and denaturation of GOx, the nonionic nanogel provides a favorable microenvironment for GOx in biological media. This flow-induced immobilization method in a nonionic nanogel host matrix opens up new pathways for designing a simple, fast, biocompatible, and cost-effective process to immobilize biomolecules that are averse to ionic environments.

Laundry pod and non-pod detergent related emergency department visits occurring in children in the USA.

PubMed

Swain, Thomas A; McGwin, Gerald; Griffin, Russell

2016-12-01

Previous studies have reported that children are at risk of severe injuries from exposure to laundry detergent pods. For the first time, this study sought to compare demographic and exposure characteristics and risk among children exposed to pod and non-pod laundry detergents presenting to emergency departments (EDs). Data from the National Electronic Injury Surveillance System (NEISS) from 2012-2014 were used. All observations with injuries involving laundry detergent (NEISS code 0949) were included in this study. The χ 2 test was used for bivariate analysis and logistic regression was used to determine the OR and 95% CI of hospitalisation for pod related versus non-pod laundry detergent exposures. From 2012-2014, there were an estimated 26 062 non-pod and 9814 pod laundry detergent related exposures among those aged 18 years and younger. For pod detergent, children aged 0-5 years had the most injuries. Poisoning (71.3%) was the most common diagnosis for pod detergent while contact dermatitis (72.2%) was most common for non-pod detergent. Hospitalisation occurred in 12.5% of pod detergent cases and just 3.0% of non-pod cases. Compared with non-pod detergent, those exposed to pod detergent were 4 times as likely to be hospitalised (OR 4.02; 95% CI 1.96 to 8.24). A greater effort should be made to appropriately educate the public about the dangers of laundry detergents, specifically pods, so a safe home environment can be established. While new regulations such as childproof containers, opaque packaging, and less appealing and colourful pods could reduce the number of pod related ED visits for children, caregivers should store detergents, along with other chemicals, in a secure location where children cannot easily access them. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Detergent effects on enzyme activity and solubilization of lipid bilayer membranes.

PubMed

Womack, M D; Kendall, D A; MacDonald, R C

1983-09-07

Over 50 detergents were tested to establish which would be most effective in releasing proteins from membrane-bounded compartments without denaturing them. Various concentrations each of detergent were tested for two activities: (1) solubilization of egg phospholipid liposomes as measured by reduction of turbidity and (2) effect of detergent concentration on the activities of soluble, hydrolytic enzymes. Those detergents most effective in solubilizing 0.2% lipid and least detrimental to enzymes were five pure, synthetic compounds recently introduced: CHAPS, CHAPSO, Zwittergents 310 and 312, and octylglucoside. Industrial detergents were generally much inferior, insofar as they solubilized membranes inefficiently and/or inactivated certain hydrolytic enzymes readily. The five detergents were characterized by (a) an unusually high critical micelle concentration and (b) a preference for forming mixed micelles with lipids instead of forming pure micelles, as indicated by an ability to solubilize lipid at concentrations of detergent significantly below the critical micelle concentration. This characteristic permits solubilization of high concentrations of membrane below the critical micelle concentration of the detergent so that protein denaturation is minimized. A generally applicable guideline that emerged from this study is that detergents should be used at approximately their critical micelle concentration which should not be exceeded by the concentration of membrane. Similar considerations should apply to the use of detergents in purifying and reconstituting intrinsic membrane proteins.

NMR spectroscopic and analytical ultracentrifuge analysis of membrane protein detergent complexes.

PubMed

Maslennikov, Innokentiy; Kefala, Georgia; Johnson, Casey; Riek, Roland; Choe, Senyon; Kwiatkowski, Witek

2007-11-08

Structural studies of integral membrane proteins (IMPs) are hampered by inherent difficulties in their heterologous expression and in the purification of solubilized protein-detergent complexes (PDCs). The choice and concentrations of detergents used in an IMP preparation play a critical role in protein homogeneity and are thus important for successful crystallization. Seeking an effective and standardized means applicable to genomic approaches for the characterization of PDCs, we chose 1D-NMR spectroscopic analysis to monitor the detergent content throughout their purification: protein extraction, detergent exchange, and sample concentration. We demonstrate that a single NMR measurement combined with a SDS-PAGE of a detergent extracted sample provides a useful gauge of the detergent's extraction potential for a given protein. Furthermore, careful monitoring of the detergent content during the process of IMP production allows for a high level of reproducibility. We also show that in many cases a simple sedimentation velocity measurement provides sufficient data to estimate both the oligomeric state and the detergent-to-protein ratio in PDCs, as well as to evaluate the homogeneity of the samples prior to crystallization screening. The techniques presented here facilitate the screening and selection of the extraction detergent, as well as help to maintain reproducibility in the detergent exchange and PDC concentration procedures. Such reproducibility is particularly important for the optimization of initial crystallization conditions, for which multiple purifications are routinely required.

NMR spectroscopic and analytical ultracentrifuge analysis of membrane protein detergent complexes

PubMed Central

Maslennikov, Innokentiy; Kefala, Georgia; Johnson, Casey; Riek, Roland; Choe, Senyon; Kwiatkowski, Witek

2007-01-01

Background Structural studies of integral membrane proteins (IMPs) are hampered by inherent difficulties in their heterologous expression and in the purification of solubilized protein-detergent complexes (PDCs). The choice and concentrations of detergents used in an IMP preparation play a critical role in protein homogeneity and are thus important for successful crystallization. Results Seeking an effective and standardized means applicable to genomic approaches for the characterization of PDCs, we chose 1D-NMR spectroscopic analysis to monitor the detergent content throughout their purification: protein extraction, detergent exchange, and sample concentration. We demonstrate that a single NMR measurement combined with a SDS-PAGE of a detergent extracted sample provides a useful gauge of the detergent's extraction potential for a given protein. Furthermore, careful monitoring of the detergent content during the process of IMP production allows for a high level of reproducibility. We also show that in many cases a simple sedimentation velocity measurement provides sufficient data to estimate both the oligomeric state and the detergent-to-protein ratio in PDCs, as well as to evaluate the homogeneity of the samples prior to crystallization screening. Conclusion The techniques presented here facilitate the screening and selection of the extraction detergent, as well as help to maintain reproducibility in the detergent exchange and PDC concentration procedures. Such reproducibility is particularly important for the optimization of initial crystallization conditions, for which multiple purifications are routinely required. PMID:17988403

Detection of antibiotics in goat's milk: effect of detergents on the response of microbial inhibitor tests.

PubMed

Romero, Tamara; Beltrán, María Carmen; Althaus, Rafael Lisandro; Molina, María Pilar

2014-08-01

The aim of the study was to evaluate the interference of acid and alkaline detergents employed in the cleaning of milking equipment of caprine dairy farms on the performance of microbial tests used in antibiotic control (BRT MRL, Delvotest MCS, and Eclipse 100). Eight concentrations of commercial detergents, five acid (0-0.25%) and five alkaline (0-1%) were add to antimicrobial-free goat's milk to evaluate the detergent effect on the response of microbial inhibitor tests. To evaluate the effect of detergents on the detection capability of microbial tests two detergents at 0.5 ml/l (one acid and one basic) and eight concentrations of four β-lactam antibiotics (ampicillin, amoxicillin, cloxacillin and benzylpenicillin) were used. Milk without detergents was used as control. The spiked samples were analysed twelve times by three microbial tests. The results showed that the presence of acid detergents did not affect the response of microbial tests for any of the concentrations tested. However, at concentrations equal to or greater than 2 ml/l alkaline detergents positive results were found in microbial tests (16.7-100%). The detection limits of the screening tests for penicillins were not modified substantially by the presence of detergents. In general, the presence of acid and alkaline detergents in goat's milk did not produce a great interference in the microbial tests, only high concentrations of detergents could cause non-compliant results, but these concentrations are difficult to find in practice if proper cleaning procedures are applied in goat dairy farms.

VERB [TM] Summer Scorecard: Increasing Tween Girls' Vigorous Physical Activity

ERIC Educational Resources Information Center

Alfonso, Moya L.; Thompson, Zachary; McDermott, Robert J.; Colquitt, Gavin; Jones, Jeffery A.; Bryant, Carol A.; Courtney, Anita H.; Davis, Jenna L.; Zhu, Yiliang

2013-01-01

Objective: We assessed changes in the frequency of self-reported physical activity (PA) among tween girls exposed and not exposed to the VERB [TM] Summer Scorecard (VSS) intervention in Lexington, Kentucky, during 2004, 2006, and 2007. Methods: Girls who reported 0-1 day per week of PA were classi?ed as having "little or no" PA. Girls…

Factors Associated with Tweens' Intentions to Sustain Participation in an Innovative Community-Based Physical Activity Intervention

ERIC Educational Resources Information Center

DeBate, Rita D.; McDermott, Robert J.; Baldwin, Julie A.; Bryant, Carol A.; Courtney, Anita H.; Hogeboom, David L.; Nickelson, Jen; Phiilips, Leah M.; Alfonso, Moya L.

2009-01-01

Background: Participation in free-time play, including individual and group activities, is important during youth as patterns of physical activity established then persist into adulthood. The VERB Summer Scorecard (VSS) intervention is an innovative physical activity promotion initiative that offers tweens (8-13 year-olds) opportunities to be…

Consumer Socialisation and Value Orientations among Estonian and Chinese Young People

ERIC Educational Resources Information Center

Waerdahl, Randi; Kalmus, Veronika; Keller, Margit

2011-01-01

This paper asks if Estonian and Chinese tweens' access to pocket money influences their brand valuation, as well as value orientations in the context of perceived peer popularity and personal well-being. Surveys conducted in autumns 2006 (China n = 188) and 2007 (Estonia n = 111) show an inherent cultural resistance among tweens in both countries…

Method for Performing Aerobic Plate Counts of Anhydrous Cosmetics Utilizing Tween 60 and Arlacel 80 as Dispersing Agents

PubMed Central

McConville, John F.; Anger, Claude B.; Anderson, David W.

1974-01-01

An aqueous diluent containing Tween 60 and Arlacel 80 gave greater recovery of microorganisms when compared with two common diluents as determined by aerobic plate count of inoculated anhydrous cosmetics. The greater recovery was caused by better dispersion of the anhydrous cosmetics in the diluents. Images PMID:4203790

Detergent-mediated protein aggregation

PubMed Central

Neale, Chris; Ghanei, Hamed; Holyoake, John; Bishop, Russell E.; Privé, Gilbert G.; Pomès, Régis

2016-01-01

Because detergents are commonly used to solvate membrane proteins for structural evaluation, much attention has been devoted to assessing the conformational bias imparted by detergent micelles in comparison to the native environment of the lipid bilayer. Here, we conduct six 500-ns simulations of a system with >600,000 atoms to investigate the spontaneous self assembly of dodecylphosphocholine detergent around multiple molecules of the integral membrane protein PagP. This detergent formed equatorial micelles in which acyl chains surround the protein’s hydrophobic belt, confirming existing models of the detergent solvation of membrane proteins. In addition, unexpectedly, the extracellular and periplasmic apical surfaces of PagP interacted with the headgroups of detergents in other micelles 85 and 60% of the time, respectively, forming complexes that were stable for hundreds of nanoseconds. In some cases, an apical surface of one molecule of PagP interacted with an equatorial micelle surrounding another molecule of PagP. In other cases, the apical surfaces of two molecules of PagP simultaneously bound a neat detergent micelle. In these ways, detergents mediated the non-specific aggregation of folded PagP. These simulation results are consistent with dynamic light scattering experiments, which show that, at detergent concentrations ≥600 mM, PagP induces the formation of large scattering species that are likely to contain many copies of the PagP protein. Together, these simulation and experimental results point to a potentially generic mechanism of detergent-mediated protein aggregation. PMID:23466535

40 CFR 80.141 - Interim detergent gasoline program.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) “Carburetor Cleanliness Test Procedure, State-of-the-Art Summary, Report: 1973-1981”, Coordinating Research... ultimate consumer; (ii) All additized post-refinery component (PRC); and (iii) All detergent additives sold... who manufacture, supply, or transfer detergent additives or detergent-additized post-refinery...

Identification of detergents for forensic fiber analysis.

PubMed

Heider, Emily C; Mujumdar, Nirvani; Campiglia, Andres D

2016-11-01

Trace fibers are an important form of trace evidence, and identification of exogenous substances on textile fibers provides valuable information about the origin of the fiber. Laundering textiles can provide a unique fluorescent spectral signature of the whitening agent in the detergent that adsorbs to the fiber. Using fluorescence microscopy, the spectral characteristics of seven detergents adsorbed to single fibers drawn from laundered textiles were investigated, and principal component analysis of clusters was used to characterize the type of detergent on the fiber. On dyed nylon fibers, spectra from eight different detergent pairs could be resolved and washed validation fibers correctly classified. On dyed acrylic fibers, five different detergent pairs could be resolved and identified. Identification of the detergent type may prove useful in matching a trace fiber to its bulk specimen of origin.

Effect of dodecyl maltoside detergent on rhodopsin stability and function.

PubMed

Ramon, Eva; Marron, Jordi; del Valle, Luis; Bosch, Laia; Andrés, Anna; Manyosa, Joan; Garriga, Pere

2003-12-01

Detergent-solubilized bovine rhodopsin produces mixed detergent/lipid/protein micelles. The effect of dodecyl maltoside detergent on the thermal stability of dark-state rhodopsin, and upon formation of the different intermediates after rhodopsin photobleaching (metarhodopsin II and metarhodopsin III), and upon transducin activation has been studied. No significant effect is observed for the thermal stability of dark-state rhodopsin in the range of detergent concentrations studied, but a decrease in the stability of metarhodopsin II and an increase in metarhodopsin III formation is observed with decreasing detergent concentrations. The transducin activation process is also affected by the presence of detergent indicating that this process is dependent on the lipid micro-environment and membrane fluidity, and this stresses the importance of the native lipid environment in rhodopsin normal function.

Structural features of the nonionic surfactants stabilizing long-lived bubble nuclei

NASA Technical Reports Server (NTRS)

Darrigo, J. S.

1980-01-01

A study of the effects of various electrolytes and one organic compound on bubble production in agarose gels is presented. Several preparations of ultrapure agarose were compared for 42 electrolytes and phenol to identify trends in bubble formation. The anion and cation sequences of bubble suppression are similar to processes for salting out of nonionic surfactants. The reduction of bubble number by polyvalent ions and 1% phenol suggests that the polar portions of these nonionic surfactants represent amide groups. The evidence for amide groups is consistent with the relative positions of Mg(2+) in all cation sequences; this result makes it unlikely that either linkages contribute to the hydrophilicity of the nonionic surfactants stabilizing bubble nuclei in the different aqueous gels tested.

Detergent enhances binding of a secreted HLA-A2 molecule to solid phase peptides.

PubMed

Tussey, L G; Frelinger, J A

1991-11-01

We have constructed a secreted analogue (sA2) of the human class I molecule HLA-A2. sA2 was affinity purified both in the presence and absence of detergent and the effects of detergent on the magnitude and specificity of A2 binding to solid phase peptides tested. sA2 purified in the presence of detergent and detergent-solubilized A2 are shown to function comparably in the binding of the synthetic peptide M.Y + 57-68, a known T-cell epitope derived from the influenza A matrix protein. The molecules binding to M.Y + 57-68 typically represent 8% to 10% of the added protein. In contrast, less than 1% of sA2 protein purified in the absence of detergent binds M.Y + 57-68. This reduced binding is not due to a change in the affinity of sA2 for M.Y + 57-68. Addition of detergent at various stages of the purification and iodination procedures indicates that the longer the sA2 molecules are exposed to detergent the better they bind. However, the concentration of detergent during the actual binding assay does not appear to be critical. We also find that while the sA2-detergent and the sA2-no detergent molecules differ in the extent to which they bind various peptides, they do not differ in their patterns of binding. We conclude that detergent probably does not influence the specificity of class I/peptide binding but does increase the number of sA2 molecules that can participate in the binding of peptide either by generating and stabilizing "empty" sA2 molecules or by stabilizing a structure that is more amenable to binding peptide.

Deuterated detergents for structural and functional studies of membrane proteins: Properties, chemical synthesis and applications.

PubMed

Hiruma-Shimizu, Kazumi; Shimizu, Hiroki; Thompson, Gary S; Kalverda, Arnout P; Patching, Simon G

2015-01-01

Detergents are amphiphilic compounds that have crucial roles in the extraction, purification and stabilization of integral membrane proteins and in experimental studies of their structure and function. One technique that is highly dependent on detergents for solubilization of membrane proteins is solution-state NMR spectroscopy, where detergent micelles often serve as the best membrane mimetic for achieving particle sizes that tumble fast enough to produce high-resolution and high-sensitivity spectra, although not necessarily the best mimetic for a biomembrane. For achieving the best quality NMR spectra, detergents with partial or complete deuteration can be used, which eliminate interfering proton signals coming from the detergent itself and also eliminate potential proton relaxation pathways and strong dipole-dipole interactions that contribute line broadening effects. Deuterated detergents have also been used to solubilize membrane proteins for other experimental techniques including small angle neutron scattering and single-crystal neutron diffraction and for studying membrane proteins immobilized on gold electrodes. This is a review of the properties, chemical synthesis and applications of detergents that are currently commercially available and/or that have been synthesized with partial or complete deuteration. Specifically, the detergents are sodium dodecyl sulphate (SDS), lauryldimethylamine-oxide (LDAO), n-octyl-β-D-glucoside (β-OG), n-dodecyl-β-D-maltoside (DDM) and fos-cholines including dodecylphosphocholine (DPC). The review also considers effects of deuteration, detergent screening and guidelines for detergent selection. Although deuterated detergents are relatively expensive and not always commercially available due to challenges associated with their chemical synthesis, they will continue to play important roles in structural and functional studies of membrane proteins, especially using solution-state NMR.

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.

[Response of the algae Gymnodinium kovalevskii (Dinophyta) to exposure to synthetic detergents and distillation].

PubMed

Aĭzdaĭcher, N A

2000-01-01

The effects of synthetic detergents and combined effects of synthetic detergents and water freshening on growth characteristics of the alga Gymnodinium kovalevskii (Dinophyta) were studied. Low concentrations of synthetic detergents (0.1 and 1.0 mg/l) stimulated the algal growth. Elevated concentrations inhibited cell division, affected their motility and induced morphological changes. Contamination with synthetic detergents adversely affected the adaptation plasticity of algae with respect to salinity.

Designing Mixed Detergent Micelles for Uniform Neutron Contrast

DOE PAGES

Oliver, Ryan C.; Pingali, Sai Venkatesh; Urban, Volker S.

2017-09-29

Micelle-forming detergents provide an amphipathic environment that mimics lipid bilayers and are important tools used to solubilize and stabilize membrane proteins in solution for in vitro structural investigations. Small-angle neutron scattering (SANS) performed at the neutron contrast match point of detergent molecules allows observing the scattering signal from membrane proteins unobstructed by contributions from the detergent. However, we show here that even for a perfectly average-contrast matched detergent there arises significant core-shell scattering from the contrast difference between aliphatic detergent tails and hydrophilic head groups. This residual signal at the average detergent contrast match point interferes with interpreting structural datamore » of membrane proteins. This complication is often made worse by the presence of excess empty (protein-free) micelles. Here, we present an approach for the rational design of mixed micelles containing a deuterated detergent analog, which eliminates neutron contrast between core and shell, and allows the micelle scattering to be fully contrast matched to unambiguously resolve membrane protein structure using solution SANS.« less

Designing Mixed Detergent Micelles for Uniform Neutron Contrast

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

Oliver, Ryan C.; Pingali, Sai Venkatesh; Urban, Volker S.

Micelle-forming detergents provide an amphipathic environment that mimics lipid bilayers and are important tools used to solubilize and stabilize membrane proteins in solution for in vitro structural investigations. Small-angle neutron scattering (SANS) performed at the neutron contrast match point of detergent molecules allows observing the scattering signal from membrane proteins unobstructed by contributions from the detergent. However, we show here that even for a perfectly average-contrast matched detergent there arises significant core-shell scattering from the contrast difference between aliphatic detergent tails and hydrophilic head groups. This residual signal at the average detergent contrast match point interferes with interpreting structural datamore » of membrane proteins. This complication is often made worse by the presence of excess empty (protein-free) micelles. Here, we present an approach for the rational design of mixed micelles containing a deuterated detergent analog, which eliminates neutron contrast between core and shell, and allows the micelle scattering to be fully contrast matched to unambiguously resolve membrane protein structure using solution SANS.« less

Designer lipid-like peptides: a class of detergents for studying functional olfactory receptors using commercial cell-free systems.

PubMed

Corin, Karolina; Baaske, Philipp; Ravel, Deepali B; Song, Junyao; Brown, Emily; Wang, Xiaoqiang; Wienken, Christoph J; Jerabek-Willemsen, Moran; Duhr, Stefan; Luo, Yuan; Braun, Dieter; Zhang, Shuguang

2011-01-01

A crucial bottleneck in membrane protein studies, particularly G-protein coupled receptors, is the notorious difficulty of finding an optimal detergent that can solubilize them and maintain their stability and function. Here we report rapid production of 12 unique mammalian olfactory receptors using short designer lipid-like peptides as detergents. The peptides were able to solubilize and stabilize each receptor. Circular dichroism showed that the purified olfactory receptors had alpha-helical secondary structures. Microscale thermophoresis suggested that the receptors were functional and bound their odorants. Blot intensity measurements indicated that milligram quantities of each olfactory receptor could be produced with at least one peptide detergent. The peptide detergents' capability was comparable to that of the detergent Brij-35. The ability of 10 peptide detergents to functionally solubilize 12 olfactory receptors demonstrates their usefulness as a new class of detergents for olfactory receptors, and possibly other G-protein coupled receptors and membrane proteins.

Wheat germ cell-free expression: Two detergents with a low critical micelle concentration allow for production of soluble HCV membrane proteins.

PubMed

Fogeron, Marie-Laure; Badillo, Aurélie; Jirasko, Vlastimil; Gouttenoire, Jérôme; Paul, David; Lancien, Loick; Moradpour, Darius; Bartenschlager, Ralf; Meier, Beat H; Penin, François; Böckmann, Anja

2015-01-01

Membrane proteins are notoriously difficult to express in a soluble form. Here, we use wheat germ cell-free expression in the presence of various detergents to produce the non-structural membrane proteins 2, 4B and 5A of the hepatitis C virus (HCV). We show that lauryl maltose neopentyl glycol (MNG-3) and dodecyl octaethylene glycol ether (C12E8) detergents can yield essentially soluble membrane proteins at detergent concentrations that do not inhibit the cell-free reaction. This finding can be explained by the low critical micelle concentration (CMC) of these detergents, which keeps the monomer concentrations low while at the same time providing the necessary excess of detergent concentration above CMC required for full target protein solubilization. We estimate that a tenfold excess of detergent micelles with respect to the protein concentration is sufficient for solubilization, a number that we propose as a guideline for detergent screening assays. Copyright © 2014 Elsevier Inc. All rights reserved.

Designer Lipid-Like Peptides: A Class of Detergents for Studying Functional Olfactory Receptors Using Commercial Cell-Free Systems

PubMed Central

Corin, Karolina; Baaske, Philipp; Ravel, Deepali B.; Song, Junyao; Brown, Emily; Wang, Xiaoqiang; Wienken, Christoph J.; Jerabek-Willemsen, Moran; Duhr, Stefan; Luo, Yuan; Braun, Dieter; Zhang, Shuguang

2011-01-01

A crucial bottleneck in membrane protein studies, particularly G-protein coupled receptors, is the notorious difficulty of finding an optimal detergent that can solubilize them and maintain their stability and function. Here we report rapid production of 12 unique mammalian olfactory receptors using short designer lipid-like peptides as detergents. The peptides were able to solubilize and stabilize each receptor. Circular dichroism showed that the purified olfactory receptors had alpha-helical secondary structures. Microscale thermophoresis suggested that the receptors were functional and bound their odorants. Blot intensity measurements indicated that milligram quantities of each olfactory receptor could be produced with at least one peptide detergent. The peptide detergents' capability was comparable to that of the detergent Brij-35. The ability of 10 peptide detergents to functionally solubilize 12 olfactory receptors demonstrates their usefulness as a new class of detergents for olfactory receptors, and possibly other G-protein coupled receptors and membrane proteins. PMID:22132066

A high-throughput differential filtration assay to screen and select detergents for membrane proteins

PubMed Central

Vergis, James M.; Purdy, Michael D.; Wiener, Michael C.

2015-01-01

Structural studies on integral membrane proteins are routinely performed on protein–detergent complexes (PDCs) consisting of purified protein solubilized in a particular detergent. Of all the membrane protein crystal structures solved to date, a subset of only four detergents has been used in more than half of these structures. Unfortunately, many membrane proteins are not well behaved in these four detergents and/or fail to yield well-diffracting crystals. Identification of detergents that maintain the solubility and stability of a membrane protein is a critical step and can be a lengthy and “protein-expensive” process. We have developed an assay that characterizes the stability and size of membrane proteins exchanged into a panel of 94 commercially available and chemically diverse detergents. This differential filtration assay (DFA), using a set of filtered microplates, requires sub-milligram quantities of purified protein and small quantities of detergents and other reagents and is performed in its entirety in several hours. PMID:20667442

Modification, characterization and investigations of key factors controlling the transport of modified nano zero-valent iron (nZVI) in porous media.

PubMed

Saha, Amal Krishna; Sinha, Alok; Pasupuleti, Srinivas

2018-01-25

Enhancement of nano zero-valent iron (nZVI) stability and transport in the subsurface environment is important for in situ degradation of contaminants. Various biodegradable dispersants (poly (acrylic acid) (PAA), Tween 20 and Reetha Extracts) have been tested to evaluate their effectiveness in this regard. Application of dispersants during the synthesis of nZVI have positively affected the reduction in particle size. The transport capacity in terms of fraction elution at different pore water velocities and collector grain size (filter media) was analyzed using correlation equation for the filtration model by Rajagopalan and Tien (RT model). At a surfactant concentration of 5% for PAA, Tween 20 and Reetha (Sapindus trifoliata) extracts, the lowest particle size and the highest zeta potential achieved are 8.67 nm and -55.29 mV, 75.24 nm and -62.68 mV, 61.6 nm and -37.82 mV, respectively. The trend of colloidal stability by The Derjaguin-Landau-Verwey-Overbeek (DLVO) Theory model for PAA and Reetha applied concentration was 3% > 4% > 5% > 2% > 1% > 0%. For Tween 20, modified nZVI particle shows a higher repulsive force with increasing Tween 20 concentration. Results indicated that some mechanisms such as aggregation, ripening and surface modification with different carrier pore water velocities had a considerable impact on nZVI retention in porous media. The results indicate that natural surfactant like Reetha extracts exhibits an alternative potential capacity for nZVI modification in comparison with synthetic surfactants (PAA and Tween 20).

Mycoremediation of manganese and phenanthrene by Pleurotus eryngii mycelium enhanced by Tween 80 and saponin.

PubMed

Wu, Minghui; Xu, Yongan; Ding, Wenbo; Li, Yuanyuan; Xu, Heng

2016-08-01

Bioremediation of areas co-contaminated with metals and polycyclic aromatic hydrocarbons (PAHs) by mushrooms has attracted considerable attention in recent years. In this study, Pleurotus eryngii was introduced for the removal of Mn and phenanthrene (Phe) from potato liquid medium (PDL) simultaneously. Effects of Tween 80 and saponin on P. eryngii growth together with Mn uptake as well as Phe removal were investigated. Although pollutants had a negative effect on mycelial morphology and growth, P. eryngii could still tolerate and remove Mn and Phe. Tween 80 increased removal of Mn and Phe through increase of P. eryngii growth, Phe solubility, pollutants bioavailability, and specific surface area of mycelium pellets, moreover, the activities of manganese peroxidase (MnP) and laccase, which played an important role on PAHs biodegradation. The maximal removal of Mn and Phe was achieved (92.17 and 93.85 % after 15 days incubation, respectively) with 0.6 g L(-1) Tween 80. Treatments with saponin markedly inhibited P. eryngii growth (50.17-66.32 % lower relative to control) due to its fungistatic activity. Nevertheless, saponin could slightly enhance Phe removal through increasing solubility of Phe, and Phe removal rate varied from 80.53 to 87.06 % in saponin treatments. Joint stress of Mn and Phe induced a strong antioxidative response, and superoxide dismutase (SOD) activity decreased in surfactants-treated mycelium compared with control. Generally, Tween 80 was more suitable for strengthening mycoremediation by P. eryngii than saponin, and could be a promising alternative for the remediation of heavy metals and PAHs co-contaminated sites by mushrooms.

[Effect of Tween 80 on yuxingcao injection and volatile oils from Houttuynia cordata].

PubMed

Tan, Zhigao; Chao, Zhimao; Sui, Yu; Liu, Haiping; Wu, Xiaoyi; Sun, Jian; Yan, Han

2011-01-01

To research the effect of polysorbate 80 (Tween 80) on Yuxingcao injection and volatile oils from Houttuynia cordata. 1H-NMR spectra of aldehydic and new matter in Yuxingcao injection, volatile oils of H. cordata, and solutions of Tween 80 and volatile oil of H. cordata are determined and compared from various angles of growing origin, storage temperature, and storage time. Three aldehydic singlets in 1H-NMR spectra of every volatile oil from 4 aerial part of H. cordata were observed. These aldehydic peaks were basically disappeared and a new peak at delta 8.30 was found in 1H-NMR spectra of the volatile oil solutions in tween 80. Any obvious aldehydic peak in 1H-NMR spectra did not be observed in Yuxincao injection. A weak peak at 8 8.30 was found in 1H-NMR spectra in Yuxincao injection, and the peak high of delta 8.30 was remarked gone up when the injection was stored in 40 degrees C for 1 to 3 months. Tween 80 might cause the obvious reduce of aldehydic compounds contents and the production of a novel singal at delta 8.30 in 1H-NMR spectra when it was mixed with the volatile oil from the aerial part of H. cordata. The novel signal at delta 8.30 in 1H-NMR spectra existed in Yuxincao injection and was very small, but was increased remarkably when the Yuxincao injection was stored at 40 degrees C for 1 month at least.

Correlates of Initial Recall of a Multimedia Communication Campaign to Promote Physical Activity among Tweens: the WIXX Campaign.

PubMed

Bélanger-Gravel, Ariane; Cutumisu, Nicoleta; Gauvin, Lise; Lagarde, François; Laferté, Marilie

2017-01-01

This study examined factors associated with children's and parents' recall of a communication campaign aimed at promoting children's physical activity. A cross-sectional population-based telephone survey was conducted among 1001 children and their parents. Respondents were recruited through a random digit dialing procedure. Respondents' recall of the campaign, beliefs, sociodemographics as well as levels of physical activity and sedentary behaviors were self-reported. Logistic regression analyses were conducted for tweens and their parents separately. Girls (odds ratio [OR] = 2.1; 95%confidence interval (CI): 1.3, 3.5) were more likely to have unaided recall when compared to boys. Tweens in primary school (OR = 1.9; 95%CI: 1.0, 3.4 and OR = 2.1; 95%CI: 1.4, 3.0) and those speaking French (OR = 3.3; 95%CI: 1.4, 8.1 and OR = 2.9; 95%CI: 1.8, 4.7) were more likely to have unaided and aided recall, respectively. Among parents, tweens' unaided (OR = 12.0; 95%CI: 5.2, 28.1) and aided (OR = 3.3; 95%CI: 1.5, 7.3) recall, obesity status (OR = 2.6; 95%CI: 1.3, 5.3), and low income (OR = 5.2; 95%CI: 1.9, 14.3) were positively associated with recall. Additional beliefs were associated with tweens' and parents' recall of the campaign. The association between sex, language, and recall is in line with the branding strategy adopted and no clear evidence for communication inequalities was observed.

Concentrated liquid detergent pod ingestion in children.

PubMed

Sidhu, Natasha; Jaeger, Matthew W

2014-12-01

Concentrated liquid detergent pods are an emerging public health hazard, especially in pediatric patients. Ingestion is a more common route of exposure for liquid detergent pods compared with non-pod detergents and it tends to be associated with more severe adverse effects. We present 3 cases that demonstrate the varied clinical symptoms resulting from detergent pod ingestion. These cases not only demonstrate findings such as gastrointestinal and respiratory symptoms but also show more rare neurological symptoms. The cases highlight the dangers of concentrated liquid detergent pod ingestion. To help prevent further life-threatening injuries, there is a need for more consumer information and provider knowledge about the potential adverse complications.

Perturbations of Native Membrane Protein Structure in Alkyl Phosphocholine Detergents: A Critical Assessment of NMR and Biophysical Studies

PubMed Central

2018-01-01

Membrane proteins perform a host of vital cellular functions. Deciphering the molecular mechanisms whereby they fulfill these functions requires detailed biophysical and structural investigations. Detergents have proven pivotal to extract the protein from its native surroundings. Yet, they provide a milieu that departs significantly from that of the biological membrane, to the extent that the structure, the dynamics, and the interactions of membrane proteins in detergents may considerably vary, as compared to the native environment. Understanding the impact of detergents on membrane proteins is, therefore, crucial to assess the biological relevance of results obtained in detergents. Here, we review the strengths and weaknesses of alkyl phosphocholines (or foscholines), the most widely used detergent in solution-NMR studies of membrane proteins. While this class of detergents is often successful for membrane protein solubilization, a growing list of examples points to destabilizing and denaturing properties, in particular for α-helical membrane proteins. Our comprehensive analysis stresses the importance of stringent controls when working with this class of detergents and when analyzing the structure and dynamics of membrane proteins in alkyl phosphocholine detergents. PMID:29488756

Irritancy potential of 17 detergents used commonly by the Indian household.

PubMed

Austoria, A J; Lakshmi, Chembolli; Srinivas, C R; Anand, C V; Mathew, A C

2010-01-01

Detergents are used by almost every household in the developed and developing world. Soap and most detergents are anionic surfactants and attack the horny layer of the skin and increase its permeability with little or no inflammatory change and may result in hand eczema, which is very distressing and incapacitating. To evaluate the irritant potential of common household detergents (laundry and dish wash) used by the Indian population using a 24-hour patch test and to convincingly educate the patients on the detergents less likely to cause irritation in the particular individual. Seventeen commonly used detergents found in Indian market were included in the study, of which, 12 were laundry detergents (powders--seven, bar soap--five) and five were dish wash detergents (powder--one, liquid--one, bar soap--three). The irritant potential of the 17 detergents were evaluated in 30 volunteers. Thirty microliters of each of the detergent bar solutions, distilled water (negative control), and 20% SDS (positive control) were applied to Finn chambers with a micropipette and occluded for 24 hours. Erythema, scaling, and edema were graded in comparison to the reaction at the negative control site (distilled water) for each volunteer separately. The scoring of erythema/dryness and wrinkling on a 0-4 point scale and edema on another 0-4 point scale was based on the Draize scale. The pH of each of the detergent solutions was determined using litmus papers (Indikrom papers from Qualigens fine chemicals). The difference between detergents (F value) was significant for erythema/dryness and wrinkling (F = 3.374; p = 0.000), but not significant for edema (F = 1.297; p = 0.194). [Table 2] lists the means for erythema/dryness and wrinkling, and edema. The F value of the totals of the means for erythema/dryness and wrinkling and edema was significant (F = 2.495; p = 0.001). The pH of all the detergents was found to be alkaline except Pril utensil cleaner which tested acidic (pH 6). The positive control, 20% SDS also tested acidic (pH 6). Similar to patch testing in allergic contact dermatitis, 24-hour patch testing with detergent solutions (8% w/v), will educate the patient on what detergent to avoid. This may bring down the total medication requirement and frequent hospital consultations for these patients.

Effect of Antibiotics and Antibiofilm Agents in the Ultrastructure and Development of Biofilms Developed by Nonpigmented Rapidly Growing Mycobacteria.

PubMed

Muñoz-Egea, María-Carmen; García-Pedrazuela, María; Mahillo-Fernandez, Ignacio; Esteban, Jaime

2016-01-01

We analyze the effect of amikacin, ciprofloxacin, and clarithromycin, alone and associated with N-acetylcysteine (NAC) and Tween 80, at different times and concentrations in nonpigmented rapidly growing mycobacteria (NPRGM) biofilms. For this purpose, confocal laser scanning microscopy and image analysis were used to study the development and behavior of intrinsic autofluorescence, covered area, thickness, and cell viability in NPRGM biofilms after adding antibiotics alone and associated with antibiofilm agents. In this study, ciprofloxacin is the most active antibiotic against this type of biofilm and thickness is the most affected parameter. NAC and Tween 80 combined with antibiotics exert a synergistic effect in increasing the percentage of dead bacteria and also reducing the percentage of covered surface and thickness of NPRGM biofilms. Tween 80 seems to be an antibiofilm agent more effective than NAC due to its higher reduction in the percentage of cover surface and thickness. In conclusion, the results obtained in this work show that phenotypic parameters (thickness, percentage of covered surface, autofluorescence, percentage of live/dead bacteria) are affected by combining antibiotics and antibiofilm agents, ciprofloxacin and Tween 80 being the most active agents against NPRGM biofilms.

Selective differential human blood bilayer media for isolation of Gardnerella (Haemophilus) vaginalis.

PubMed Central

Totten, P A; Amsel, R; Hale, J; Piot, P; Holmes, K K

1982-01-01

New selective and differential human blood bilayer agar media with Tween 80 (HBT medium) or without Tween 80 (HB medium), developed for the isolation of Gardnerella (Haemophilus) vaginalis, permitted significantly higher G. vaginalis isolation rates than have been obtained for other media used for this purpose. HB medium consists of a basal layer of Columbia agar base containing colistin and naladixic acid with added amphotericin B and an overlayer of the same composition plus 5% human blood. HBT agar also contains Proteose Peptone No. 3 (Difco Laboratories) and Tween 80 in the basal layer and the overlayer. Both Tween 80 and the bilayer composition enhanced G. vaginalis production of human blood hemolysis, permitting detection of this organism even in the presence of heavy growth of other vaginal flora. The use of HB or HBT medium thus permitted the demonstration that G. vaginalis was present in vaginal fluid from a large percentage (up to 68%) of normal women. However, the concentration of G. vaginalis was found by semiquantitative analysis to be significantly higher in vaginal fluid from women with nonspecific vaginitis than in fluid from normal women. Images PMID:6764766

Citral stabilization and characterization of nanoemulsions stabilized by a mixture of gelatin and Tween 20 in an acidic system.

PubMed

Tian, Huaixiang; Li, Danfeng; Xu, Ting; Hu, Jing; Rong, Yuzhi; Zhao, Bo

2017-07-01

Citral is one of the most important flavor compounds in fresh juice and lemon oil. Unfortunately, citral is chemically unstable and degrades over time in aqueous solutions. Here, citral nanoemulsions including a mixture of gelatin and Tween 20 as emulsifiers were produced in an effort to maintain the stability of citral in an acidic system. The mean droplet size and polydispersity index of the citral nanoemulsion were 467.83 nm and 0.259 respectively when the mass ratio of gelatin/Tween 20 was 3:1 and the total emulsifier concentration of the emulsion system was 10 g kg -1 . The citral nanoemulsion remained stable during storage for 14 days at 30 °C. Therefore this nanoemulsion system effectively protected citral from degradation and decreased the formation of off-flavor compounds (e.g. p-cymene, p-cresol and p-methylacetophenone) relative to a single emulsifier. The mixture of gelatin and Tween 20 enhanced the stability of citral under acidic conditions and could be used as an effective emulsifier to protect citral from degradation under acidic environments in the food industry. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Deposition of porous low-k thin films using Tween 80 porogen for ILD application in ULSI circuits

NASA Astrophysics Data System (ADS)

Mhaisagar, Yogesh S.; Kawishwar, Renuka; Joshi, Bhavana N.; Mahajan, A. M.

2012-10-01

The porous silica low-k thin films were deposited by using Sol-gel spin coating technique. The tetraethylorthosilicate (TEOS) was used as a source of Si and the porogen Tween 80 was used for the introduction of porosity of the films. The chemical bondings of porous low-k SiO2 films have been realized by using Fourier transform infrared spectroscopy (FT-IR). The appearance of stretching, bending and rocking peaks at 1075.8, 967, 426 cm-1 respectively confirms the formation of Si-O-Si network. The Refractive index (RI) and thickness of the films were determined by using ellipsometer. Further, from RI the density and porosity of the films was estimated using standard formula. As from results it's seems that the density of the films reduces after the addition of Tween 80. The lowest value of films density after the addition of Tween 80 was found to be 1.27 g/cm3. The reduction in the film density results in increase of the porosity of films due to the removal of porogen during the curing. The increase in film porosity from 6% to 45% resulted in lower in the dielectric constant to 2.58.

Entomotoxicity, protease and chitinase activity of Bacillus thuringiensis fermented wastewater sludge with a high solids content.

PubMed

Brar, Satinder K; Verma, M; Tyagi, R D; Valéro, J R; Surampalli, R Y

2009-10-01

This study investigated the production of biopesticides, protease and chitinase activity by Bacillus thuringiensis grown in raw wastewater sludge at high solids concentration (30 g/L). The rheology of wastewater sludge was modified with addition of Tween-80 (0.2% v/v). This addition resulted in 1.6 and 1.3-fold increase in cell and spore count, respectively. The maximum specific growth rate (micro(max)) augmented from 0.17 to 0.22 h(-1) and entomotoxicity (Tx) increased by 29.7%. Meanwhile, volumetric mass transfer coefficient (k(L)a) showed marked variations during fermentation, and oxygen uptake rate (OUR) increased 2-fold. The proteolytic activity increased while chitinase decreased for Tween amended wastewater sludge, but the entomotoxicity increased. The specific entomotoxicity followed power law when plotted against spore concentration and the relation between Tx and protease activity was linear. The viscosity varied and volume percent of particles increased in Tween-80 amended wastewater sludge and particle size (D(50)) decreased at the end of fermentation. Thus, there was an increase in entomotoxicity at higher suspended solids (30 g/L) as Tween addition improved rheology (viscosity, particle size, surface tension); enhanced maximum growth rate and OUR.

40 CFR 417.160 - Applicability; description of the manufacture of liquid detergents subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manufacture of liquid detergents subcategory. 417.160 Section 417.160 Protection of Environment ENVIRONMENTAL... CATEGORY Manufacture of Liquid Detergents Subcategory § 417.160 Applicability; description of the manufacture of liquid detergents subcategory. The provisions of this subpart are applicable to discharges...

76 FR 9013 - Agency Information Collection Activities; Proposed Collection; Comment Request; Detergent Gasoline

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-16

... Activities; Proposed Collection; Comment Request; Detergent Gasoline AGENCY: Environmental Protection Agency... this action are those who (1) Manufacture gasoline, post-refinery component, or detergent additives, (2) blend detergent additives into gasoline or post-refinery component, or (3) transport or receive a...

Effects of various polyoxyethylene sorbitan monooils (Tweens) and sodium dodecyl sulfate on reflux synthesis of copper nanoparticles

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

Zhang Xifeng; Yin Hengbo; Cheng Xiaonong

2006-11-09

Size-controlled synthesis of phase pure Cu nanoparticles was carried out by using copper sulfate pentahydrate as a precursor, ascorbic acid as a reductant, Tweens and sodium dodecyl sulfate (SDS) as modifiers in an aqueous solution at 80 deg. C. The as-prepared Cu nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and Fourier transform infrared (FT-IR). The stabilizing effects of SDS and Tweens on the Cu nanoparticles should be through the coordination between Cu nanoparticles and the respective sulfate group and oxygen-containing bond. The synergic effect of the composite SDS and Tweensmore » on Cu nanoparticles was different from those arising from the individuals.« less

Behavior of microemulsion systems of virgin coconut oil (VCO) using igepal CO-520 and tween 80 surfactant

NASA Astrophysics Data System (ADS)

Safuan, A.; Hamdan, S.; Laili, C. R.

2017-09-01

Virgin Coconut Oil (VCO) has been applied in many application and products. Formation of microemulsion region with surfactant was investigated by using phase diagram. The surfactants used are igepal CO-520 and tween 80. The studies showed that formation of microemulsion region were dependent on the behaviour of the surfactant toward VCO. The result showed that microemulsion regions were present in igepal CO-520 system formed a larger water-in-oil microemulsion region compared to tween 80 system. Certain weight ratios of VCO to surfactants were studied by using evaporation test in order to study the water loss of the microemulsion in ambient condition. The evaporation rate of samples was varies depending their compositon of VCO, surfactant and water.

40 CFR 417.150 - Applicability; description of the manufacture of spray dried detergents subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manufacture of spray dried detergents subcategory. 417.150 Section 417.150 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Spray Dried Detergents Subcategory § 417.150 Applicability; description of the manufacture of spray dried detergents subcategory. The provisions of this subpart are...

40 CFR 417.180 - Applicability; description of the manufacture of drum dried detergents subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manufacture of drum dried detergents subcategory. 417.180 Section 417.180 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.180 Applicability; description of the manufacture of drum dried detergents subcategory. The provisions of this subpart are...

40 CFR 80.156 - Liability for violations of the interim detergent program controls and prohibitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., or detergent-additized post-refinery component satisfied relevant requirements when it left their... detergent satisfied all relevant requirements when it left the detergent manufacturer's control; and (B... manufactured. (2) The test results must accurately establish that, when it left the manufacturer's control, the...

[Diagnostic Significance of BAT in Anaphylaxis to Non-ionic Contrast Media].

PubMed

Zhang, Hao-yue; Xu, Su-jun; Tang, Xiao-xian; Niu, Ji-jun; Guo, Xiang-jie; Gao, Cai-rong

2015-06-01

To investigate the diagnostic significance of basophil activation test (BAT) in anaphylaxis to non-ionic contrast media through testing the content of CD63, mast cell-carboxypeptidase A3 (MC-CPA3), and terminal complement complex SC5b-9 of the individuals by testing their levels in the normal immune group and the anaphylaxis groups to β-lactam drugs and non -ionic contrast media. The CD63 expression of basophilic granulocyte in blood was detected by flow cytometry. The levels of MC-CPA3 in blood serum and SC5b-9 in blood plasma were detected by ELISA. The CD63 expression of basophilic granulocyte in blood, the levels of MC-CPA3 and SC5b-9 of anaphylaxis to non-ionic contrast media and β-lactam drugs were significantly higher than that in normal immune group (P < 0.05). There is activation of basophilic granulocytes, mast cells and complement system in anaphylaxis to non-ionic contrast media. BAT can be used to diagnose the anaphylaxis to non-ionic contrast media.

40 CFR 80.163 - Detergent certification options.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Detergent certification options. 80... options. To be used to satisfy the detergency requirements under § 80.161(a), a detergent additive must be certified in accordance with the requirements of one or more of the options and suboptions described in this...

40 CFR 417.170 - Applicability; description of the manufacture of detergents by dry blending subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manufacture of detergents by dry blending subcategory. 417.170 Section 417.170 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.170 Applicability; description of the manufacture of detergents by dry blending subcategory. The provisions of this subpart are...

40 CFR 417.190 - Applicability; description of the manufacture of detergent bars and cakes subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manufacture of detergent bars and cakes subcategory. 417.190 Section 417.190 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Detergent Bars and Cakes Subcategory § 417.190 Applicability; description of the manufacture of detergent bars and cakes subcategory. The provisions of this subpart are...

40 CFR 80.156 - Liability for violations of the interim detergent program controls and prohibitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... base gasoline component, the detergent component, or the detergent-additized post-refinery component of... component of any post-refinery component or gasoline in the storage tank containing gasoline found to be in... evidence, that the gasoline or detergent carrier caused the violation. (2) Post-refinery component non...

40 CFR 80.161 - Detergent additive certification program.

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements. For a detergent additive package to be certified as eligible for use by detergent blenders in...: (i) The compositional data required under § 79.21(a) of this chapter shall include the information... chapter shall be reported to EPA in units of gallons of detergent additive package per 1000 gallons of...

40 CFR 80.161 - Detergent additive certification program.

Code of Federal Regulations, 2011 CFR

2011-07-01

... requirements. For a detergent additive package to be certified as eligible for use by detergent blenders in...: (i) The compositional data required under § 79.21(a) of this chapter shall include the information... chapter shall be reported to EPA in units of gallons of detergent additive package per 1000 gallons of...

40 CFR 80.161 - Detergent additive certification program.

Code of Federal Regulations, 2012 CFR

2012-07-01

... requirements. For a detergent additive package to be certified as eligible for use by detergent blenders in...: (i) The compositional data required under § 79.21(a) of this chapter shall include the information... chapter shall be reported to EPA in units of gallons of detergent additive package per 1000 gallons of...

Cellular localization and detergent dependent oligomerization of rice allene oxide synthase-1.

PubMed

Yoeun, Sereyvath; Kim, Jeong-Il; Han, Oksoo

2015-01-01

Allene oxide synthase-1 from Oryza sativa (OsAOS1) localizes to the chloroplast, but lacks a putative chloroplast targeting sequence typically found in dicot AOS. Here, kinetic parameters and the oligomerization state/subunit composition of OsAOS1 were characterized in vitro in the absence or presence of detergent micelles. The catalytic efficiency (k(cat)/K(m)) of OsAOS1 reached a maximum near the critical micelle concentration for polyoxyethylene 10 tridecyl ether. Native gel analysis showed that OsAOS1 exists as a multimer in the absence of detergent micelles. The multimeric form of OsAOS1 was stably cross-linked in the absence of detergents, while only monomeric OsAOS1 was detected in the presence of detergent micelles. Gel filtration analysis indicated that the oligomeric state of OsAOS1 depends strongly on the detergents and that the monomer becomes the predominant form in the presence of detergent micelles. These data suggest that the detergent-dependent oligomeric state of OsAOS1 is an important factor for the regulation of its catalytic efficiency.

A strategic approach for direct recovery and stabilization of Fusarium sp. ICT SAC1 cutinase from solid state fermented broth by carrier free cross-linked enzyme aggregates.

PubMed

Chaudhari, Sandeep A; Singhal, Rekha S

2017-05-01

The major hurdles in commercial exploitation of cutinase (having both esterolytic and lipolytic activities) with potent industrial applications are its high production cost, operational instability and reusability. Although commercially available in immobilized form, its immobilization process (synthesis of support/carrier) makes it expensive. Herein we tried to address multiple issues of production cost, stability, and reusability, associated with cutinase. Waste watermelon rinds, an agroindustrial waste was considered as a cheap support for solid state fermentation (SSF) for cutinase production by newly isolated Fusarium sp. ICT SAC1. Subsequently, carrier free cross-linked enzyme aggregates of cutinase (cut-CLEA) directly from the SSF crude broth were developed. All the process variables affecting CLEA formation along with the different additives were evaluated. It was found that 50% (w/v) of ammonium sulphate, 125μmol of glutaraldehyde, cross-linking for 1h at 30°C and broth pH of 7.0, yielded 58.12% activity recovery. All other additives (hexane, butyric acid, sodium dodecyl sulphate, Trition-X 100, Tween-20, BSA) evaluated presented negative results to our hypothesis. Kinetics and morphology studies confirmed the diffusive nature of cut-CLEA and BSA cut-CLEA. Developed CLEA showed better thermal, solvent, detergent and storage stability, making it more elegant and efficient for industrial biocatalytic process. Copyright © 2017 Elsevier B.V. All rights reserved.

A Writer for Tweens at Heart: A Conversation with Louis Sachar

ERIC Educational Resources Information Center

Checkley, Kathy

2006-01-01

Tweens everywhere know Louis Sachar. Even if they haven't read about the quirky children and teachers of Wayside School, or blushed along with Bradley Chalkers after he was discovered in the girls' bathroom, they couldn't miss Sachar's 18th book, Holes. Published in 1998, the book earned a Newbery Medal in 1999 and landed on the silver screen in…