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Sample records for surfactant protein sp-b

  1. Conformational Stability of the NH2-Terminal Propeptide of the Precursor of Pulmonary Surfactant Protein SP-B.

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    Ángeles Bañares-Hidalgo

    Full Text Available Assembly of pulmonary surfactant lipid-protein complexes depends on conformational changes coupled with proteolytic maturation of proSP-B, the precursor of pulmonary surfactant protein B (SP-B, along the surfactant biogenesis pathway in pneumocytes. Conformational destabilization of the N-terminal propeptide of proSP-B (SP-BN triggers exposure of the mature SP-B domain for insertion into surfactant lipids. We have studied the conformational stability during GdmCl- or urea-promoted unfolding of SP-BN with trp fluorescence and circular dichroism spectroscopies. Binding of the intermediate states to bis-ANS suggests their molten globule-like character. ΔG0H2O was ~ 12.7 kJ·mol-1 either with urea or GdmCl. None of the thermal transitions of SP-BN detected by CD correspond to protein unfolding. Differential scanning calorimetry of SP-BN evidenced two endothermic peaks involved in oligomer dissociation as confirmed with 2 M urea. Ionic strength was relevant since at 150 mM NaCl, the process originating the endotherm at the highest temperature was irreversible (Tm2 = 108.5°C with an activation energy of 703.8 kJ·mol-1. At 500 mM NaCl the process became reversible (Tm2 = 114.4°C and data were fitted to the Non-two States model with two subpeaks. No free thiols in the propeptide could be titrated by DTNB with or without 5.7 M GdmCl, indicating disulfide bonds establishment.

  2. Quantitation of pulmonary surfactant protein SP-B in the absence or presence of phospholipids by enzyme-linked immunosorbent assay

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    Oviedo, J M; Valiño, F; Plasencia, I

    2001-01-01

    We have developed an enzyme-linked immunosorbent assay (ELISA) that uses polyclonal or monoclonal anti-surfactant protein SP-B antibodies to quantitate purified SP-B in chloroform/methanol and in chloroform/methanol extracts of whole pulmonary surfactant at nanogram levels. This method has been...... used to explore the effect of the presence of different phospholipids on the immunoreactivity of SP-B. Both polyclonal and monoclonal antibodies produced reproducible ELISA calibration curves for methanolic SP-B solutions with protein concentrations in the range of 20-1000 ng/mL. At these protein...... pronounced changes on the conformation of SP-B when the solvent was evaporated and dry lipid-protein films were formed, a necessary step to expose protein to antibodies in ELISA. Under these conditions, negatively charged lipids, but not zwitterionic ones, induced a marked decrease on the ellipticity of SP...

  3. Synergistic Effect of Caffeine and Glucocorticoids on Expression of Surfactant Protein B (SP-B) mRNA

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    Fehrholz, Markus; Bersani, Iliana; Kramer, Boris W.; Speer, Christian P.; Kunzmann, Steffen

    2012-01-01

    Administration of glucocorticoids and caffeine is a common therapeutic intervention in the neonatal period, but possible interactions between these substances are still unclear. The present study investigated the effect of caffeine and different glucocorticoids on expression of surfactant protein (SP)-B, crucial for the physiological function of pulmonary surfactant. We measured expression levels of SP-B, various SP-B transcription factors including erythroblastic leukemia viral oncogene homolog 4 (ErbB4) and thyroid transcription factor-1 (TTF-1), as well as the glucocorticoid receptor (GR) after administering different doses of glucocorticoids, caffeine, cAMP, or the phosphodiesterase-4 inhibitor rolipram in the human airway epithelial cell line NCI-H441. Administration of dexamethasone (1 µM) or caffeine (5 mM) stimulated SP-B mRNA expression with a maximal of 38.8±11.1-fold and 5.2±1.4-fold increase, respectively. Synergistic induction was achieved after co-administration of dexamethasone (1 mM) in combination with caffeine (10 mM) (206±59.7-fold increase, pglucocorticoids and caffeine, achieved by accumulation of intracellular cAMP. This effect was mediated by a caffeine-dependent phosphodiesterase inhibition and by upregulation of both ErbB4 and the GR. These results suggested that caffeine is able to induce the expression of SP-transcription factors and affects the signaling pathways of glucocorticoids, amplifying their effects. Co-administration of caffeine and corticosteroids may therefore be of benefit in surfactant homeostasis. PMID:23272120

  4. Surfactant proteins SP-B and SP-C and their precursors in bronchoalveolar lavages from children with acute and chronic inflammatory airway disease

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    Winter Tobias

    2008-04-01

    Full Text Available Abstract Background The surfactant proteins B (SP-B and C (SP-C are important for the stability and function of the alveolar surfactant film. Their involvement and down-regulation in inflammatory processes has recently been proposed, but their level during neutrophilic human airway diseases are not yet known. Methods We used 1D-electrophoresis and Western blotting to determine the concentrations and molecular forms of SP-B and SP-C in bronchoalveolar lavage (BAL fluid of children with different inflammatory airway diseases. 21 children with cystic fibrosis, 15 with chronic bronchitis and 14 with pneumonia were included and compared to 14 healthy control children. Results SP-B was detected in BAL of all 64 patients, whereas SP-C was found in BAL of all but 3 children; those three BAL fluids had more than 80% neutrophils, and in two patients, who were re-lavaged later, SP-C was then present and the neutrophil count was lower. SP-B was mainly present as a dimer, SP-C as a monomer. For both qualitative and quantitative measures of SP-C and SP-B, no significant differences were observed between the four evaluated patient groups. Conclusion Concentration or molecular form of SP-B and SP-C is not altered in BAL of children with different acute and chronic inflammatory lung diseases. We conclude that there is no down-regulation of SP-B and SP-C at the protein level in inflammatory processes of neutrophilic airway disease.

  5. Surfactant proteins SP-B and SP-C and their precursors in bronchoalveolar lavages from children with acute and chronic inflammatory airway disease.

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    Tafel, Oliver; Latzin, Philipp; Paul, Karl; Winter, Tobias; Woischnik, Markus; Griese, Matthias

    2008-04-11

    The surfactant proteins B (SP-B) and C (SP-C) are important for the stability and function of the alveolar surfactant film. Their involvement and down-regulation in inflammatory processes has recently been proposed, but their level during neutrophilic human airway diseases are not yet known. We used 1D-electrophoresis and Western blotting to determine the concentrations and molecular forms of SP-B and SP-C in bronchoalveolar lavage (BAL) fluid of children with different inflammatory airway diseases. 21 children with cystic fibrosis, 15 with chronic bronchitis and 14 with pneumonia were included and compared to 14 healthy control children. SP-B was detected in BAL of all 64 patients, whereas SP-C was found in BAL of all but 3 children; those three BAL fluids had more than 80% neutrophils, and in two patients, who were re-lavaged later, SP-C was then present and the neutrophil count was lower. SP-B was mainly present as a dimer, SP-C as a monomer. For both qualitative and quantitative measures of SP-C and SP-B, no significant differences were observed between the four evaluated patient groups. Concentration or molecular form of SP-B and SP-C is not altered in BAL of children with different acute and chronic inflammatory lung diseases. We conclude that there is no down-regulation of SP-B and SP-C at the protein level in inflammatory processes of neutrophilic airway disease.

  6. Synthetic surfactant based on analogues of SP-B and SP-C is superior to single-peptide surfactants in ventilated premature rabbits.

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    Almlén, Andreas; Walther, Frans J; Waring, Alan J; Robertson, Bengt; Johansson, Jan; Curstedt, Tore

    2010-06-01

    Respiratory distress syndrome (RDS) is currently treated with surfactant preparations obtained from natural sources and attempts to develop equally active synthetic surfactants have been unsuccessful. One difference in composition is that naturally derived surfactants contain the two hydrophobic proteins SP-B and SP-C while synthetic preparations contain analogues of either SP-B or SP-C. It was recently shown that both SP-B and SP-C (or SP-C33, an SP-C analogue) are necessary to establish alveolar stability at end-expiration in a rabbit RDS model, as reflected by high lung gas volumes without application of positive end-expiratory pressure. To study the efficacy of fully synthetic surfactants containing analogues of both SP-B and SP-C compared to surfactants with only one protein analogue. Premature newborn rabbits, treated with synthetic surfactants, were ventilated for 30 min without positive end-expiratory pressure. Tidal volumes as well as lung gas volumes at end-expiration were determined. Treatment with 2% Mini-B (a short-cut version of SP-B) and 2% SP-C33, or its C-terminally truncated form SP-C30, in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol, 68:31 (w/w) resulted in median lung gas volumes of 8-9 ml/kg body weight, while animals treated with 2% Mini-B surfactant or 2% SP-C33/SP-C30 surfactant had lung gas volumes of 3-4 ml/kg, and those treated with Curosurf, a porcine surfactant, 15-17 ml/kg. In contrast, mixing SP-C33 with peptides with different distributions of positively charged and hydrophobic residues did not improve lung gas volumes. The data indicate that synthetic surfactants containing analogues of both SP-B and SP-C might be superior to single-peptide surfactants in the treatment of RDS.

  7. Surface film formation in vitro by infant and therapeutic surfactants: role of surfactant protein B.

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    Danhaive, Olivier; Chapin, Cheryl; Horneman, Hart; Cogo, Paola E; Ballard, Philip L

    2015-02-01

    Pulmonary surfactant provides an alveolar surface-active film that is critical for normal lung function. Our objective was to determine in vitro film formation properties of therapeutic and infant surfactants and the influence of surfactant protein (SP)-B content. We used a multiwell fluorescent assay measuring maximum phospholipid surface accumulation (Max), phospholipid concentration required for half-maximal film formation (½Max), and time for maximal accumulation (tMax). Among five therapeutic surfactants, calfactant (highest SP-B content) had film formation values similar to natural surfactant, and addition of SP-B to beractant (lowest SP-B) normalized its Max value. Addition of budesonide to calfactant did not adversely affect film formation. In tracheal aspirates of preterm infants with evolving chronic lung disease, SP-B content correlated with ½Max and tMax values, and SP-B supplementation of SP-B-deficient infant surfactant restored normal film formation. Reconstitution of normal surfactant indicated a role for both SP-B and SP-C in film formation. Film formation in vitro differs among therapeutic surfactants and is highly dependent on SP-B content in infant surfactant. The results support a critical role of SP-B for promoting surface film formation.

  8. Synthetic surfactant containing SP-B and SP-C mimics is superior to single-peptide formulations in rabbits with chemical acute lung injury

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    Frans J. Walther

    2014-05-01

    Full Text Available Background. Chemical spills are on the rise and inhalation of toxic chemicals may induce chemical acute lung injury (ALI/acute respiratory distress syndrome (ARDS. Although the pathophysiology of ALI/ARDS is well understood, the absence of specific antidotes has limited the effectiveness of therapeutic interventions.Objectives. Surfactant inactivation and formation of free radicals are important pathways in (chemical ALI. We tested the potential of lipid mixtures with advanced surfactant protein B and C (SP-B and C mimics to improve oxygenation and lung compliance in rabbits with lavage- and chemical-induced ALI/ARDS.Methods. Ventilated young adult rabbits underwent repeated saline lung lavages or underwent intratracheal instillation of hydrochloric acid to induce ALI/ARDS. After establishment of respiratory failure rabbits were treated with a single intratracheal dose of 100 mg/kg of synthetic surfactant composed of 3% Super Mini-B (S-MB, a SP-B mimic, and/or SP-C33 UCLA, a SP-C mimic, in a lipid mixture (DPPC:POPC:POPG 5:3:2 by weight, the clinical surfactant Infasurf®, a bovine lung lavage extract with SP-B and C, or synthetic lipids alone. End-points consisted of arterial oxygenation, dynamic lung compliance, and protein and lipid content in bronchoalveolar lavage fluid. Potential mechanism of surfactant action for S-MB and SP-C33 UCLA were investigated with captive bubble surfactometry (CBS assays.Results. All three surfactant peptide/lipid mixtures and Infasurf equally lowered the minimum surface tension on CBS, and also improved oxygenation and lung compliance. In both animal models, the two-peptide synthetic surfactant with S-MB and SP-C33 UCLA led to better arterial oxygenation and lung compliance than single peptide synthetic surfactants and Infasurf. Synthetic surfactants and Infasurf improved lung function further in lavage- than in chemical-induced respiratory failure, with the difference probably due to greater capillary

  9. Superficial disposition of the N-terminal region of the surfactant protein SP-C and the absence of specific SP-B-SP-C interactions in phospholipid bilayers

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    Plasencia, I; Cruz, A; Casals, C

    2001-01-01

    A dansylated form of porcine surfactant-associated protein C (Dns-SP-C), bearing a single dansyl group at its N-terminal end, has been used to characterize the lipid-protein and protein-protein interactions of SP-C reconstituted in phospholipid bilayers, using fluorescence spectroscopy...... of the N-terminal segment of the protein into less polar environments that originate during protein lateral segregation. This suggests that conformation and interactions of the N-terminal segment of SP-C could be important in regulating the lateral distribution of the protein in surfactant bilayers...

  10. Effects of Natural versus Synthetic Surfactant with SP-B and SP-C Analogs in a Porcine Model of Meconium Aspiration Syndrome.

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    Salvesen, Bodil; Curstedt, Tore; Mollnes, Tom Eirik; Saugstad, Ola Didrik

    2014-01-01

    Meconium displaces surfactant from the alveolar surface and inhibits its function. The development of active synthetic surfactants is complicated, especially to synthesize the hydrophobic surfactant proteins SP-B and SP-C. A synthetic surfactant, CHF5633 containing SP-B and SP-C analogs, has been designed to act similarly to the natural surfactant poractant alfa. To test the resistance to meconium inactivation of CHF5633 compared to poractant alfa. Secondary outcome measurements were respiratory and inflammatory parameters. Twenty-six newborn pigs, bodyweight 1.4-2.0 kg were randomized to receive either poractant alfa or CHF5633. After anesthesia, surgery and final stabilization, meconium was instilled endotracheally followed by surfactant. Bronchial lavage fluid was obtained before intervention and every second hour. Respiratory parameters were registered and blood samples drawn before intervention and every hour. Surfactant was inactivated in both groups 6 h after meconium instillation, but CHF5633 was more resistant than poractant alfa in terms of lipid peroxidation. Respiratory parameters were similar in both groups. Inflammatory and hemostatic parameters differed between groups, suggesting that the surfactants may play different roles in the meconium-induced inflammatory process. Due to the differential effects and complex pattern observed, the data do not indicate that one of the surfactants was superior with respect to inflammatory and hemostatic responses. This study indicates that CHF5633 is as efficient as poractant alfa in experimental meconium aspiration syndrome. © 2013 S. Karger AG, Basel.

  11. Synthetic lung surfactants containing SP-B and SP-C peptides plus novel phospholipase-resistant lipids or glycerophospholipids

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    Robert H. Notter

    2016-10-01

    Full Text Available Background This study examines the biophysical and preclinical pulmonary activity of synthetic lung surfactants containing novel phospholipase-resistant phosphonolipids or synthetic glycerophospholipids combined with Super Mini-B (S-MB DATK and/or SP-Css ion-lock 1 peptides that replicate the functional biophysics of surfactant proteins (SP-B and SP-C. Phospholipase-resistant phosphonolipids used in synthetic surfactants are DEPN-8 and PG-1, molecular analogs of dipalmitoyl phosphatidylcholine (DPPC and palmitoyl-oleoyl phosphatidylglycerol (POPG, while glycerophospholipids used are active lipid components of native surfactant (DPPC:POPC:POPG 5:3:2 by weight. The objective of the work is to test whether these novel lipid/peptide synthetic surfactants have favorable preclinical activity (biophysical, pulmonary for therapeutic use in reversing surfactant deficiency or dysfunction in lung disease or injury. Methods Surface activity of synthetic lipid/peptide surfactants was assessed in vitro at 37 °C by measuring adsorption in a stirred subphase apparatus and dynamic surface tension lowering in pulsating and captive bubble surfactometers. Shear viscosity was measured as a function of shear rate on a Wells-Brookfield micro-viscometer. In vivo pulmonary activity was determined by measuring lung function (arterial oxygenation, dynamic lung compliance in ventilated rats and rabbits with surfactant deficiency/dysfunction induced by saline lavage to lower arterial PO2 to <100 mmHg, consistent with clinical acute respiratory distress syndrome (ARDS. Results Synthetic surfactants containing 5:3:2 DPPC:POPC:POPG or 9:1 DEPN-8:PG-1 combined with 3% (by wt of S-MB DATK, 3% SP-Css ion-lock 1, or 1.5% each of both peptides all adsorbed rapidly to low equilibrium surface tensions and also reduced surface tension to ≤1 mN/m under dynamic compression at 37 °C. However, dual-peptide surfactants containing 1.5% S-MB DATK + 1.5% SP-Css ion-lock 1 combined with

  12. Synthetic lung surfactants containing SP-B and SP-C peptides plus novel phospholipase-resistant lipids or glycerophospholipids.

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    Notter, Robert H; Gupta, Rohun; Schwan, Adrian L; Wang, Zhengdong; Shkoor, Mohanad Gh; Walther, Frans J

    2016-01-01

    This study examines the biophysical and preclinical pulmonary activity of synthetic lung surfactants containing novel phospholipase-resistant phosphonolipids or synthetic glycerophospholipids combined with Super Mini-B (S-MB) DATK and/or SP-Css ion-lock 1 peptides that replicate the functional biophysics of surfactant proteins (SP)-B and SP-C. Phospholipase-resistant phosphonolipids used in synthetic surfactants are DEPN-8 and PG-1, molecular analogs of dipalmitoyl phosphatidylcholine (DPPC) and palmitoyl-oleoyl phosphatidylglycerol (POPG), while glycerophospholipids used are active lipid components of native surfactant (DPPC:POPC:POPG 5:3:2 by weight). The objective of the work is to test whether these novel lipid/peptide synthetic surfactants have favorable preclinical activity (biophysical, pulmonary) for therapeutic use in reversing surfactant deficiency or dysfunction in lung disease or injury. Surface activity of synthetic lipid/peptide surfactants was assessed in vitro at 37 °C by measuring adsorption in a stirred subphase apparatus and dynamic surface tension lowering in pulsating and captive bubble surfactometers. Shear viscosity was measured as a function of shear rate on a Wells-Brookfield micro-viscometer. In vivo pulmonary activity was determined by measuring lung function (arterial oxygenation, dynamic lung compliance) in ventilated rats and rabbits with surfactant deficiency/dysfunction induced by saline lavage to lower arterial PO 2 to surfactants containing 5:3:2 DPPC:POPC:POPG or 9:1 DEPN-8:PG-1 combined with 3% (by wt) of S-MB DATK, 3% SP-Css ion-lock 1, or 1.5% each of both peptides all adsorbed rapidly to low equilibrium surface tensions and also reduced surface tension to ≤1 mN/m under dynamic compression at 37 °C. However, dual-peptide surfactants containing 1.5% S-MB DATK + 1.5% SP-Css ion-lock 1 combined with 9:1 DEPN-8:PG-1 or 5:3:2 DPPC:POPC:POPG had the greatest in vivo activity in improving arterial oxygenation and dynamic lung

  13. SP-B and SP-C containing new synthetic surfactant for treatment of extremely immature lamb lung.

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    Sato, Atsuyasu; Ikegami, Machiko

    2012-01-01

    Although superiority of synthetic surfactant over animal-driven surfactant has been known, there is no synthetic surfactant commercially available at present. Many trials have been made to develop synthetic surfactant comparable in function to animal-driven surfactant. The efficacy of treatment with a new synthetic surfactant (CHF5633) containing dipalmitoylphosphatidylcholine, phosphatidylglycerol, SP-B analog, and SP-C analog was evaluated using immature newborn lamb model and compared with animal lung tissue-based surfactant Survanta. Lambs were treated with a clinical dose of 200 mg/kg CHF5633, 100 mg/kg Survanta, or air after 15 min initial ventilation. All the lambs treated with air died of respiratory distress within 90 min of age. During a 5 h study period, Pco(2) was maintained at 55 mmHg with 24 cmH(2)O peak inspiratory pressure for both groups. The preterm newborn lamb lung functions were dramatically improved by CHF5633 treatment. Slight, but significant superiority of CHF5633 over Survanta was demonstrated in tidal volume at 20 min and dynamic lung compliance at 20 and 300 min. The ultrastructure of CHF5633 was large with uniquely aggregated lipid particles. Increased uptake of CHF5633 by alveolar monocytes for catabolism was demonstrated by microphotograph, which might be associated with the higher treatment dose of CHF5633. The higher catabolism of CHF5633 was also suggested by the similar amount of surfactant lipid in bronchoalveolar lavage fluid (BALF) between CHF5633 and Survanta groups, despite the 2-fold higher treatment dose of CHF5633. Under the present ventilation protocol, lung inflammation was minimal for both groups, evaluated by inflammatory cell numbers in BALF and expression of IL-1β, IL-6, IL-8, and TNFα mRNA in the lung tissue. In conclusion, the new synthetic surfactant CHF5633 was effective in treating extremely immature newborn lambs with surfactant deficiency during the 5 h study period.

  14. SP-B and SP-C containing new synthetic surfactant for treatment of extremely immature lamb lung.

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    Atsuyasu Sato

    Full Text Available Although superiority of synthetic surfactant over animal-driven surfactant has been known, there is no synthetic surfactant commercially available at present. Many trials have been made to develop synthetic surfactant comparable in function to animal-driven surfactant. The efficacy of treatment with a new synthetic surfactant (CHF5633 containing dipalmitoylphosphatidylcholine, phosphatidylglycerol, SP-B analog, and SP-C analog was evaluated using immature newborn lamb model and compared with animal lung tissue-based surfactant Survanta. Lambs were treated with a clinical dose of 200 mg/kg CHF5633, 100 mg/kg Survanta, or air after 15 min initial ventilation. All the lambs treated with air died of respiratory distress within 90 min of age. During a 5 h study period, Pco(2 was maintained at 55 mmHg with 24 cmH(2O peak inspiratory pressure for both groups. The preterm newborn lamb lung functions were dramatically improved by CHF5633 treatment. Slight, but significant superiority of CHF5633 over Survanta was demonstrated in tidal volume at 20 min and dynamic lung compliance at 20 and 300 min. The ultrastructure of CHF5633 was large with uniquely aggregated lipid particles. Increased uptake of CHF5633 by alveolar monocytes for catabolism was demonstrated by microphotograph, which might be associated with the higher treatment dose of CHF5633. The higher catabolism of CHF5633 was also suggested by the similar amount of surfactant lipid in bronchoalveolar lavage fluid (BALF between CHF5633 and Survanta groups, despite the 2-fold higher treatment dose of CHF5633. Under the present ventilation protocol, lung inflammation was minimal for both groups, evaluated by inflammatory cell numbers in BALF and expression of IL-1β, IL-6, IL-8, and TNFα mRNA in the lung tissue. In conclusion, the new synthetic surfactant CHF5633 was effective in treating extremely immature newborn lambs with surfactant deficiency during the 5 h study period.

  15. Biomimicry of surfactant protein C.

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    Brown, Nathan J; Johansson, Jan; Barron, Annelise E

    2008-10-01

    Since the widespread use of exogenous lung surfactant to treat neonatal respiratory distress syndrome, premature infant survival and respiratory morbidity have dramatically improved. Despite the effectiveness of the animal-derived surfactant preparations, there still remain some concerns and difficulties associated with their use. This has prompted investigation into the creation of synthetic surfactant preparations. However, to date, no clinically used synthetic formulation is as effective as the natural material. This is largely because the previous synthetic formulations lacked analogues of the hydrophobic proteins of the lung surfactant system, SP-B and SP-C, which are critical functional constituents. As a result, recent investigation has turned toward the development of a new generation of synthetic, biomimetic surfactants that contain synthetic phospholipids along with a mimic of the hydrophobic protein portion of lung surfactant. In this Account, we detail our efforts in creating accurate mimics of SP-C for use in a synthetic surfactant replacement therapy. Despite SP-C's seemingly simple structure, the predominantly helical protein is extraordinarily challenging to work with given its extreme hydrophobicity and structural instability, which greatly complicates the creation of an effective SP-C analogue. Drawing inspiration from Nature, two promising biomimetic approaches have led to the creation of rationally designed biopolymers that recapitulate many of SP-C's molecular features. The first approach utilizes detailed SP-C structure-activity relationships and amino acid folding propensities to create a peptide-based analogue, SP-C33. In SP-C33, the problematic and metastable polyvaline helix is replaced with a structurally stable polyleucine helix and includes a well-placed positive charge to prevent aggregation. SP-C33 is structurally stable and eliminates the association propensity of the native protein. The second approach follows the same design

  16. New surfactant with SP-B and C analogs gives survival benefit after inactivation in preterm lambs.

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    Matthias Seehase

    Full Text Available BACKGROUND: Respiratory distress syndrome in preterm babies is caused by a pulmonary surfactant deficiency, but also by its inactivation due to various conditions, including plasma protein leakage. Surfactant replacement therapy is well established, but clinical observations and in vitro experiments suggested that its efficacy may be impaired by inactivation. A new synthetic surfactant (CHF 5633, containing synthetic surfactant protein B and C analogs, has shown comparable effects on oxygenation in ventilated preterm rabbits versus Poractant alfa, but superior resistance against inactivation in vitro. We hypothesized that CHF 5633 is also resistant to inactivation by serum albumin in vivo. METHODOLOGY/PRINCIPAL FINDINGS: Nineteen preterm lambs of 127 days gestational age (term = 150 days received CHF 5633 or Poractant alfa and were ventilated for 48 hours. Ninety minutes after birth, the animals received albumin with CHF 5633 or Poractant alfa. Animals received additional surfactant if P(aO(2 dropped below 100 mmHg. A pressure volume curve was done post mortem and markers of pulmonary inflammation, surfactant content and biophysiology, and lung histology were assessed. CHF 5633 treatment resulted in improved arterial pH, oxygenation and ventilation efficiency index. The survival rate was significantly higher after CHF 5633 treatment (5/7 than after Poractant alfa (1/8 after 48 hours of ventilation. Biophysical examination of the surfactant recovered from bronchoalveolar lavages revealed that films formed by CHF 5633-treated animals reached low surface tensions in a wider range of compression rates than films from Poractant alfa-treated animals. CONCLUSIONS: For the first time a synthetic surfactant containing both surfactant protein B and C analogs showed significant benefit over animal derived surfactant in an in vivo model of surfactant inactivation in premature lambs.

  17. Surfactant protein B inhibits secretory phospholipase A2 hydrolysis of surfactant phospholipids

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    Grier, Bonnie L.; Waite, B. Moseley; Veldhuizen, Ruud A.; Possmayer, Fred; Yao, Li-Juan; Seeds, Michael C.

    2012-01-01

    Hydrolysis of surfactant phospholipids (PL) by secretory phospholipases A2 (sPLA2) contributes to surfactant damage in inflammatory airway diseases such as acute lung injury/acute respiratory distress syndrome. We and others have reported that each sPLA2 exhibits specificity in hydrolyzing different PLs in pulmonary surfactant and that the presence of hydrophilic surfactant protein A (SP-A) alters sPLA2-mediated hydrolysis. This report tests the hypothesis that hydrophobic SP-B also inhibits sPLA2-mediated surfactant hydrolysis. Three surfactant preparations were used containing varied amounts of SP-B and radiolabeled tracers of phosphatidylcholine (PC) or phosphatidylglycerol (PG): 1) washed ovine surfactant (OS) (pre- and postorganic extraction) compared with Survanta (protein poor), 2) Survanta supplemented with purified bovine SP-B (1–5%, wt/wt), and 3) a mixture of dipalmitoylphosphatidylcholine (DPPC), 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC), and 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) (DPPC:POPC:POPG, 40:40:20) prepared as vesicles and monomolecular films in the presence or absence of SP-B. Hydrolysis of PG and PC by Group IB sPLA2 (PLA2G1A) was significantly lower in the extracted OS, which contains SP-B, compared with Survanta (P = 0.005), which is SP-B poor. Hydrolysis of PG and PC in nonextracted OS, which contains all SPs, was lower than both Survanta and extracted OS. When Survanta was supplemented with 1% SP-B, PG and PC hydrolysis by PLA2G1B was significantly lower (P hydrolysis by both PLA2G1B and Group IIA sPLA2 (PLA2G2A). In films, PLA2G1B hydrolyzed surfactant PL monolayers at surface pressures ≤30 mN/m (P hydrolysis can occur. These results suggest the hydrophobic SP, SP-B, protects alveolar surfactant PL from hydrolysis mediated by multiple sPLA2 in both vesicles (alveolar subphase) and monomolecular films (air-liquid interface). PMID:22037357

  18. Design of Surfactant Protein B Peptide Mimics Based on the Saposin Fold for Synthetic Lung Surfactants.

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    Walther, Frans J; Gordon, Larry M; Waring, Alan J

    2016-01-01

    Surfactant protein (SP)-B is a 79-residue polypeptide crucial for the biophysical and physiological function of endogenous lung surfactant. SP-B is a member of the Saposin or Saposin-like proteins (SAPLIP) family of proteins that share an overall three-dimensional folding pattern based on secondary structures and disulfide connectivity and exhibit a wide diversity of biological functions. Here we review the synthesis, molecular biophysics and activity of synthetic analogs of Saposin proteins designed to mimic those interactions of the parent proteins with lipids that enhance interfacial activity. Saposin proteins generally interact with target lipids as either monomers or multimers via well-defined amphipathic helices, flexible hinge domains, and insertion sequences. Based on the known 3D-structural motif for the Saposin family, we show how bioengineering techniques may be used to develop minimal peptide constructs that maintain desirable structural properties and activities in biomedical applications. One important application is the molecular design, synthesis and activity of Saposin mimics based on the SP-B structure. Synthetic lung surfactants containing active SP-B analogs may be potentially useful in treating diseases of surfactant deficiency or dysfunction including the neonatal respiratory distress syndrome and acute lung injury/acute respiratory distress syndrome.

  19. Differential susceptibility of transgenic mice expressing human surfactant protein B genetic variants to Pseudomonas aeruginosa induced pneumonia.

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    Ge, Lin; Liu, Xinyu; Chen, Rimei; Xu, Yongan; Zuo, Yi Y; Cooney, Robert N; Wang, Guirong

    2016-01-08

    Surfactant protein B (SP-B) is essential for lung function. Previous studies have indicated that a SP-B 1580C/T polymorphism (SNP rs1130866) was associated with lung diseases including pneumonia. The SNP causes an altered N-linked glycosylation modification at Asn129 of proSP-B, e.g. the C allele with this glycosylation site but not in the T allele. This study aimed to generate humanized SP-B transgenic mice carrying either SP-B C or T allele without a mouse SP-B background and then examine functional susceptibility to bacterial pneumonia in vivo. A total of 18 transgenic mouse founders were generated by the DNA microinjection method. These founders were back-crossed with SP-B KO mice to eliminate mouse SP-B background. Four founder lines expressing similar SP-B levels to human lung were chosen for further investigation. After intratracheal infection with 50 μl of Pseudomonas aeruginosa solution (1 × 10(6) CFU/mouse) or saline in SP-B-C, SP-B-T mice the mice were sacrificed 24 h post-infection and tissues were harvested. Analysis of surfactant activity revealed differential susceptibility between SP-B-C and SP-B-T mice to bacterial infection, e.g. higher minimum surface tension in infected SP-B-C versus infected SP-B-T mice. These results demonstrate for the first time that human SP-B C allele is more susceptible to bacterial pneumonia than SP-B T allele in vivo. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Pulmonary surfactant proteins and polymer combinations reduce surfactant inhibition by serum

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    Lu, Karen W.; Pérez-Gil, Jesús; Echaide, Mercedes; Taeusch, H. William

    2011-01-01

    Acute respiratory distress syndrome (ARDS) is an inflammatory condition that can be associated with capillary leak of serum into alveoli causing inactivation of surfactant. Resistance to inactivation is affected by types and concentrations of surfactant proteins, lipids, and polymers. Our aim was to investigate the effects of different combinations of these three components. A simple lipid mixture (DPPC/POPG) or a more complex lipid mixture (DPPC/POPC/POPG/cholesterol) was used. Native surfactant proteins SP-B and SP-C obtained from pig lung lavage were added either singly or combined at two concentrations. Also, non-ionic polymers polyethylene glycol and dextran and the anionic polymer hyaluronan were added either singly or in pairs with hyaluronan included. Non-ionic polymers work by different mechanisms than anionic polymers, thus the purpose of placing them together in the same surfactant mixture was to evaluate if the combination would show enhanced beneficial effects. The resulting surfactant mixtures were studied in the presence or absence of serum. A modified bubble surfactometer was used to evaluate surface activities. Mixtures that included both SP-B and SP-C plus hyaluronan and either dextran or polyethylene glycol were found to be the most resistant to inhibition by serum. These mixtures, as well as some with either SP-B or SP-C with combined polymers were as or more resistant to inactivation than native surfactant. These results suggest that improved formulations of lung surfactants are possible and may be useful in reducing some types of surfactant inactivation in treating lung injuries. PMID:21741354

  1. Developmental and Genetic Regulation of Human Surfactant Protein B in vivo

    Science.gov (United States)

    Hamvas, Aaron; Heins, Hillary B.; Guttentag, Susan H.; Wegner, Daniel J.; Trusgnich, Michelle A.; Bennet, Kate W.; Yang, Ping; Carlson, Christopher S.; An, Ping; Cole, F. Sessions

    2009-01-01

    Background Genetic and developmental disruption of surfactant protein B (SP-B) expression causes neonatal respiratory distress syndrome (RDS). Objectives: To assess developmental and genetic regulation of SP-B expression in vivo. Methods To evaluate in vivo developmental regulation of SP-B, we used immunoblotting to compare frequency of detection of mature and pro-SP-B peptides in developmentally distinct cohorts: 24 amniotic fluid samples, unfractionated tracheal aspirates from 101 infants ≥34 weeks’ gestation with (75) and without (26) neonatal RDS, and 6 nonsmoking adults. To examine genetic regulation, we used univariate and logistic regression analyses to detect associations between common SP-B (SFTPB) genotypes and SP-B peptides in the neonatal RDS cohort. Results We found pro-SP-B peptides in 24/24 amniotic fluid samples and in 100/101 tracheal aspirates from newborn infants but none in bronchoalveolar lavage from normal adults (0/6) (p < 0.001). We detected an association (p = 0.0011) between pro-SP-B peptides (Mr 40 and 42 kDa) and genotype of a nonsynonymous single nucleotide polymorphism at genomic position 1580 that regulates amino-terminus glycosylation. Conclusions Pro-SP-B peptides are more common in developmentally less mature humans. Association of genotype at genomic position 1580 with pro-SP-B peptides (Mr 40 and 42 kDa) suggests genetic regulation of amino terminus glycosylation in vivo. PMID:18776725

  2. Surfactant Proteins in Smoking-Related Lung Disease.

    Science.gov (United States)

    Papaioannou, Andriana I; Papiris, Spyridon; Papadaki, Georgia; Manali, Effrosyni D; Roussou, Aneza; Spathis, Aris; Karakitsos, Petros; Kostikas, Konstantinos

    2016-01-01

    Pulmonary surfactant is a highly surface-active mixture of proteins and lipids that is synthesized and secreted in the alveoli by type II epithelial cells and is found in the fluid lining the alveolar surface. The protein part of surfactant constitutes two hydrophilic proteins (SP-A and SP-D) that regulate surfactant metabolism and have immunologic functions, and two hydrophobic proteins (SP-B and SP-C), which play a direct role in the organization of the surfactant structure in the interphase and in the stabilization of the lipid layers during the respiratory cycle. Several studies have shown that cigarette smoke seems to affect, in several ways, both surfactant homeostasis and function. The alterations in surfactants' biophysical properties caused by cigarette smoking, contribute to the development of several smoking related lung diseases. In this review we provide information on biochemical and physiological aspects of the pulmonary surfactant and on its possible association with the development of two major chronic diseases of the lung known to be related to smoking, i.e. chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Additional information on the possible role of surfactant protein alterations and/or dysfunction in the combination of these two conditions, recently described as combined pulmonary fibrosis and emphysema (CPFE) are also provided.

  3. Surfactant protein B polymorphisms, pulmonary function and COPD in 10,231 individuals

    DEFF Research Database (Denmark)

    Bækvad-Hansen, M; Nordestgaard, B G; Dahl, Morten

    2011-01-01

    The surfactant protein (SP)-B gene may influence chronic obstructive pulmonary disease (COPD) and, thus, personalised medicine. We tested whether functional polymorphisms in SP-B (rs1130866 (1580T>C), rs2077079 (-18A>C) and rs3024791 (-384G>A)) associate with reduced lung function and risk of COPD...... polymorphisms. In conclusion, the functional rs1130866, rs2077079 and rs3024791 polymorphisms in the SP-B gene are not associated with reduced lung function or risk of COPD, making it unlikely that these variants will be useful in personalised medicine....

  4. Structural Studies of Protein-Surfactant Complexes

    International Nuclear Information System (INIS)

    Chodankar, S. N.; Aswal, V. K.; Wagh, A. G.

    2008-01-01

    The structure of protein-surfactant complexes of two proteins bovine serum albumin (BSA) and lysozyme in presence of anionic surfactant sodium dodecyl sulfate (SDS) has been studied using small-angle neutron scattering (SANS). It is observed that these two proteins form different complex structures with the surfactant. While BSA protein undergoes unfolding on addition of surfactant, lysozyme does not show any unfolding even up to very high surfactant concentrations. The unfolding of BSA protein is caused by micelle-like aggregation of surfactant molecules in the complex. On the other hand, for lysozyme protein there is only binding of individual surfactant molecules to protein. Lysozyme in presence of higher surfactant concentrations has protein-surfactant complex structure coexisting with pure surfactant micelles

  5. Depth profiles of pulmonary surfactant protein B in phosphatidylcholine bilayers, studied by fluorescence and electron spin resonance spectroscopy

    DEFF Research Database (Denmark)

    Cruz, A; Casals, C; Plasencia, I

    1998-01-01

    Pulmonary surfactant-associated protein B (SP-B) has been isolated from porcine lungs and reconstituted in bilayers of dipalmitoylphosphatidylcholine (DPPC) or egg yolk phosphatidylcholine (PC) to characterize the extent of insertion of the protein into phospholipid bilayers. The parameters...... for the interaction of SP-B with DPPC or PC using different reconstitution protocols have been estimated from the changes induced in the fluorescence emission spectrum of the single protein tryptophan. All the different reconstituted SP-B-phospholipid preparations studied had similar Kd values for the binding...... that there are significant differences in the extent of insertion of the protein, depending on the method of reconstitution. SP-B reconstituted from lipid/protein mixtures in organic solvents is inserted more deeply in PC or DPPC bilayers than the protein reconstituted by addition to preformed phospholipid vesicles...

  6. Depth profiles of pulmonary surfactant protein B in phosphatidylcholine bilayers, studied by fluorescence and electron spin resonance spectroscopy

    DEFF Research Database (Denmark)

    Cruz, A; Casals, C; Plasencia, I

    1998-01-01

    Pulmonary surfactant-associated protein B (SP-B) has been isolated from porcine lungs and reconstituted in bilayers of dipalmitoylphosphatidylcholine (DPPC) or egg yolk phosphatidylcholine (PC) to characterize the extent of insertion of the protein into phospholipid bilayers. The parameters...

  7. Biophysical mimicry of lung surfactant protein B by random nylon-3 copolymers.

    Science.gov (United States)

    Dohm, Michelle T; Mowery, Brendan P; Czyzewski, Ann M; Stahl, Shannon S; Gellman, Samuel H; Barron, Annelise E

    2010-06-16

    Non-natural oligomers have recently shown promise as functional analogues of lung surfactant proteins B and C (SP-B and SP-C), two helical and amphiphilic proteins that are critical for normal respiration. The generation of non-natural mimics of SP-B and SP-C has previously been restricted to step-by-step, sequence-specific synthesis, which results in discrete oligomers that are intended to manifest specific structural attributes. Here we present an alternative approach to SP-B mimicry that is based on sequence-random copolymers containing cationic and lipophilic subunits. These materials, members of the nylon-3 family, are prepared by ring-opening polymerization of beta-lactams. The best of the nylon-3 polymers display promising in vitro surfactant activities in a mixed lipid film. Pulsating bubble surfactometry data indicate that films containing the most surface-active polymers attain adsorptive and dynamic-cycling properties that surpass those of discrete peptides intended to mimic SP-B. Attachment of an N-terminal octadecanoyl unit to the nylon-3 copolymers, inspired by the post-translational modifications found in SP-C, affords further improvements by reducing the percent surface area compression to reach low minimum surface tension. Cytotoxic effects of the copolymers are diminished relative to that of an SP-B-derived peptide and a peptoid-based mimic. The current study provides evidence that sequence-random copolymers can mimic the in vitro surface-active behavior of lung surfactant proteins in a mixed lipid film. These findings raise the possibility that random copolymers might be useful for developing a lung surfactant replacement, which is an attractive prospect given that such polymers are easier to prepare than are sequence-specific oligomers.

  8. Surfactant protein B and A concentrations are increased in neonatal pneumonia.

    Science.gov (United States)

    D'Aronco, Sara; Simonato, Manuela; Vedovelli, Luca; Baritussio, Aldo; Verlato, Giovanna; Nobile, Stefano; Giorgetti, Chiara; Nespeca, Matteo; Carnielli, Virgilio P; Cogo, Paola E

    2015-10-01

    Term newborns with pneumonia show a reduced pulmonary compliance due to multiple and ill-defined factors. Surfactant proteins' (SPs) changes could have a role in the reduced compliance but the matter is still unsettled. The aim of this study was to clarify the meaning of SPs changes during pneumonia in term newborns. In 28 term ventilated newborns, 13 with pneumonia and 15 with no lung disease, we measured SP-B, SP-A, disaturated-phosphatidylcholine (DSPC), and total phospholipids (PL) concentrations in tracheal aspirates at intubation and close to extubation. We also measured DSPC kinetics using (U-(13)C-PA)dipalmitoyl-phosphatidylcholine. At baseline, SP-B, expressed as % of PL, was significantly different between the groups, being 3.5-fold higher in pneumonia than controls. Conversely, SP-A did not vary between the groups. At extubation, SP-B and SP-A concentrations had decreased significantly in newborns with pneumonia, while there was no significant change in controls. DSPC t1/2 was significantly shorter in the pneumonia group (11.8 (5.5-19.8) h vs. 26.6 (19.3-63.6) h, P = 0.011). In term newborns with pneumonia, SP-B increases with respect to PL, and DSPC is turned over at a faster rate. Disease's resolution is associated with the restoration of the normal ratio between SP-B and PL.

  9. Critical structural and functional roles for the N-terminal insertion sequence in surfactant protein B analogs.

    Directory of Open Access Journals (Sweden)

    Frans J Walther

    2010-01-01

    Full Text Available Surfactant protein B (SP-B; 79 residues belongs to the saposin protein superfamily, and plays functional roles in lung surfactant. The disulfide cross-linked, N- and C-terminal domains of SP-B have been theoretically predicted to fold as charged, amphipathic helices, suggesting their participation in surfactant activities. Earlier structural studies with Mini-B, a disulfide-linked construct based on the N- and C-terminal regions of SP-B (i.e., approximately residues 8-25 and 63-78, confirmed that these neighboring domains are helical; moreover, Mini-B retains critical in vitro and in vivo surfactant functions of the native protein. Here, we perform similar analyses on a Super Mini-B construct that has native SP-B residues (1-7 attached to the N-terminus of Mini-B, to test whether the N-terminal sequence is also involved in surfactant activity.FTIR spectra of Mini-B and Super Mini-B in either lipids or lipid-mimics indicated that these peptides share similar conformations, with primary alpha-helix and secondary beta-sheet and loop-turns. Gel electrophoresis demonstrated that Super Mini-B was dimeric in SDS detergent-polyacrylamide, while Mini-B was monomeric. Surface plasmon resonance (SPR, predictive aggregation algorithms, and molecular dynamics (MD and docking simulations further suggested a preliminary model for dimeric Super Mini-B, in which monomers self-associate to form a dimer peptide with a "saposin-like" fold. Similar to native SP-B, both Mini-B and Super Mini-B exhibit in vitro activity with spread films showing near-zero minimum surface tension during cycling using captive bubble surfactometry. In vivo, Super Mini-B demonstrates oxygenation and dynamic compliance that are greater than Mini-B and compare favorably to full-length SP-B.Super Mini-B shows enhanced surfactant activity, probably due to the self-assembly of monomer peptide into dimer Super Mini-B that mimics the functions and putative structure of native SP-B.

  10. Surfactant protein D in newborn infants

    DEFF Research Database (Denmark)

    Dahl, Marianne; Juvonen, Pekka Olavi; Holmskov, Uffe

    2005-01-01

    Surfactant protein D (SP-D) is a collectin that plays an important role in the innate immune system. The role of SP-D in the metabolism of surfactant is as yet quite unclear. The aims of this study were to establish normal values of SP-D in the umbilical cord blood and capillary blood of mature...

  11. [Deficiency of surfactant protein: Case report].

    Science.gov (United States)

    Milet, María Beatriz; Mena N, Patricia; Pérez, Héctor I; Espinoza, Tatiana

    Congenital surfactant deficiency is a condition infrequently diagnosed in newborns. A clinical case is presented of surfactant protein B deficiency. A review is performed on the study, treatment and differential diagnosis of surfactant protein deficiencies and infant chronic interstitial lung disease. The case is presented of a term newborn that developed respiratory distress, recurrent pulmonary opacification, and a transient response to the administration of surfactant. Immunohistochemical and genetic studies confirmed the diagnosis of surfactant protein B deficiency. Pulmonary congenital anomalies require a high index of suspicion. Surfactant protein B deficiency is clinically progressive and fatal in the majority of the cases, similar to that of ATP binding cassette subfamily A member 3 (ABCA3) deficiency. Protein C deficiency is insidious and may present with a radiological pulmonary interstitial pattern. Due to the similarity in the histological pattern, genetic studies help to achieve greater certainty in the prognosis and the possibility of providing adequate genetic counselling. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Surfactant protein B polymorphisms are associated with severe respiratory syncytial virus infection, but not with asthma

    Directory of Open Access Journals (Sweden)

    Heinzmann Andrea

    2007-05-01

    Full Text Available Abstract Background Surfactant proteins (SP are important for the innate host defence and essential for a physiological lung function. Several linkage and association studies have investigated the genes coding for different surfactant proteins in the context of pulmonary diseases such as chronic obstructive pulmonary disease or respiratory distress syndrome of preterm infants. In this study we tested whether SP-B was in association with two further pulmonary diseases in children, i. e. severe infections caused by respiratory syncytial virus and bronchial asthma. Methods We chose to study five polymorphisms in SP-B: rs2077079 in the promoter region; rs1130866 leading to the amino acid exchange T131I; rs2040349 in intron 8; rs3024801 leading to L176F and rs3024809 resulting in R272H. Statistical analyses made use of the Armitage's trend test for single polymorphisms and FAMHAP and FASTEHPLUS for haplotype analyses. Results The polymorphisms rs3024801 and rs3024809 were not present in our study populations. The three other polymorphisms were common and in tight linkage disequilibrium with each other. They did not show association with bronchial asthma or severe RSV infection in the analyses of single polymorphisms. However, haplotypes analyses revealed association of SP-B with severe RSV infection (p = 0.034. Conclusion Thus our results indicate a possible involvement of SP-B in the genetic predisposition to severe RSV infections in the German population. In order to determine which of the three polymorphisms constituting the haplotypes is responsible for the association, further case control studies on large populations are necessary. Furthermore, functional analysis need to be conducted.

  13. Cationic versus anionic surfactant in tuning the structure and interaction of nanoparticle, protein, and surfactant complexes.

    Science.gov (United States)

    Mehan, Sumit; Aswal, Vinod K; Kohlbrecher, Joachim

    2014-08-26

    The structure and interaction in complexes of anionic Ludox HS40 silica nanoparticle, anionic bovine serum albumin (BSA) protein, and cationic dodecyl trimethylammonium bromide (DTAB) surfactant have been studied using small-angle neutron scattering (SANS). The results are compared with similar complexes having anionic sodium dodecyl sulfate (SDS) surfactant (Mehan, S; Chinchalikar, A. J.; Kumar, S.; Aswal, V. K.; Schweins, R. Langmuir 2013, 29, 11290). In both cases (DTAB and SDS), the structure in nanoparticle-protein-surfactant complexes is predominantly determined by the interactions of the individual two-component systems. The nanoparticle-surfactant (mediated through protein-surfactant complex) and protein-surfactant interactions for DTAB, but nanoparticle-protein (mediated through protein-surfactant complex) and protein-surfactant interactions for SDS, are found to be responsible for the resultant structure of nanoparticle-protein-surfactant complexes. Irrespective of the charge on the surfactant, the cooperative binding of surfactant with protein leads to micellelike clusters of surfactant formed along the unfolded protein chain. The adsorption of these protein-surfactant complexes for DTAB on oppositely charged nanoparticles gives rise to the protein-surfactant complex-mediated aggregation of nanoparticles (similar to that of DTAB surfactant). It is unlike that of depletion-induced aggregation of nanoparticles with nonadsorption of protein-surfactant complexes for SDS in similarly charged nanoparticle systems (similar to that of protein alone). The modifications in nanoparticle aggregation as well as unfolding of protein in these systems as compared to the corresponding two-component systems have also been examined by selectively contrast matching the constituents.

  14. Molecular dynamics of surfactant protein C

    DEFF Research Database (Denmark)

    Ramírez, Eunice; Santana, Alberto; Cruz, Anthony

    2006-01-01

    Surfactant protein C (SP-C) is a membrane-associated protein essential for normal respiration. It has been found that the alpha-helix form of SP-C can undergo, under certain conditions, a transformation from an alpha-helix to a beta-strand conformation that closely resembles amyloid fibrils, which...

  15. Probing nanoparticle effect in protein-surfactant complexes

    Science.gov (United States)

    Mehan, Sumit; Aswal, V. K.; Kohlbrecher, J.

    2015-06-01

    SANS experiments have been carried to probe the role of anionic silica nanoparticles in the anionic BSA protein-cationic DTAB surfactant complexes. In protein-surfactant complex, surfactant molecules aggregate to form micelle-like clusters along the unfolded polypeptide chains of the protein. The nanoparticle aggregation mediated by oppositely charged protein-surfactant complex coexists with the free protein-surfactant complexes in the nanoparticle-protein-surfactant system. There is rearrangement of micelles in adsorbed protein-surfactant complex on nanoparticles in leading to their (nanoparticle) aggregation. On the other hand, the unfolding of protein in free protein-surfactant complex is found to be significantly enhanced in presence of nanoparticles.

  16. Porcine lung surfactant protein B gene (SFTPB)

    DEFF Research Database (Denmark)

    Cirera Salicio, Susanna; Fredholm, Merete

    2008-01-01

    The porcine surfactant protein B (SFTPB) is a single copy gene on chromosome 3. Three different cDNAs for the SFTPB have been isolated and sequenced. Nucleotide sequence comparison revealed six nonsynonymous single nucleotide polymorphisms (SNPs), four synonymous SNPs and an in-frame deletion of 69...

  17. Surfactant protein D is proatherogenic in mice

    DEFF Research Database (Denmark)

    Sorensen, Grith L; Madsen, Jens; Kejling, Karin

    2006-01-01

    Surfactant protein D (SP-D) is an important innate immune defense molecule that mediates clearance of pathogens and modulates the inflammatory response. Moreover, SP-D is involved in lipid homeostasis, and pulmonary accumulation of phospholipids has previously been observed in SP-D-deficient (Spd...

  18. Surfactant protein B gene polymorphism in preterm babies with respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    P.P.R. Lyra

    2011-01-01

    Full Text Available The etiology of respiratory distress syndrome (RDS is multifactorial and multigenic. Studies have suggested that polymorphisms and mutations in the surfactant protein B (SP-B gene are associated with the pathogenesis of RDS. The objectives of this study were to determine and compare the frequencies of SP-B gene polymorphisms in preterm babies with and without RDS. We studied 151 neonates: 79 preterm babies without RDS and 72 preterm newborns with RDS. The following four SP-B gene polymorphisms were analyzed: A/C at -18, C/T at 1580, A/G at 9306, and G/C at nucleotide 8714. The polymorphisms were detected by PCR amplification of genomic DNA and genotyping. The genotypes were determined using PCR-based converted restriction fragment length polymorphisms. The control group consisted of 42 (53% girls and 37 (47% boys. Weight ranged from 1170 to 3260 g and mean gestational age (GA was 33.9 weeks (range: 29 to 35 weeks and 6 days. The RDS group consisted of 31 (43% girls and 41 (57% boys. Weight ranged from 614 to 2410 g and mean GA was 32 weeks (range: 26 to 35 weeks. The logistic regression model showed that GA was the variable that most contributed to the occurrence of RDS. The AG genotype of the A/G polymorphism at position 9306 of the SP-B gene was a protective factor in this population (OR = 0.1681; 95%CI = 0.0426-0.6629. We did not detect differences in the frequencies of the other polymorphisms between the two groups of newborns.

  19. [Exogenous surfactant therapy: new synthetic surfactants].

    Science.gov (United States)

    Lacaze-Masmonteil, Th

    2008-06-01

    There are numerous pulmonary conditions in which qualitative or quantitative anomalies of the surfactant system have been demonstrated. In premature newborns with immature lungs, a functional deficit in surfactant is the main physiopathologic mechanism of the neonatal respiratory distress syndrome (RDS). Since the landmark pilot study of Fujiwara, published more than 20 years ago, the efficacy of exogenous surfactant for the treatment of neonatal RDS has been established by numerous controlled studies and meta-analyses. Enlightened by a growing insight into both the structure and function of the different surfactant components, a new generation of synthetic surfactants has been developed. Various complementary approaches have confirmed the fundamental role of the two hydrophobic proteins, SP-B and SP-C, in the surfactant system, thus opening the way to the design of analogues, either by chemical synthesis or expression in a prokaryotic system. An example of these peptide-containing synthetic surfactant preparations, lucinactant (Surfaxin), has been recently tested in comparison to a synthetic surfactant that does not contain protein as well as to animal derived surfactant preparations. Major clinical outcomes between lucinactant and animal-derived surfactant preparations were fund similar in two randomized controlled trials, opening the way to a new generation of synthetic surfactants in the near future.

  20. Molecular simulation of surfactant-assisted protein refolding

    Science.gov (United States)

    Lu, Diannan; Liu, Zheng; Liu, Zhixia; Zhang, Minlian; Ouyang, Pingkai

    2005-04-01

    Protein refolding to its native state in vitro is a challenging problem in biotechnology, i.e., in the biomedical, pharmaceutical, and food industry. Protein aggregation and misfolding usually inhibit the recovery of proteins with their native states. These problems can be partially solved by adding a surfactant into a suitable solution environment. However, the process of this surfactant-assisted protein refolding is not well understood. In this paper, we wish to report on the first-ever simulations of surfactant-assisted protein refolding. For these studies, we defined a simple model for the protein and the surfactant and investigated how a surfactant affected the folding behavior of a two-dimensional lattice protein molecule. The model protein and model surfactant were chosen such that we could capture the important features of the folding process and the interaction between the protein and the surfactant, namely, the hydrophobic interaction. It was shown that, in the absence of surfactants, a protein in an "energy trap" conformation, i.e., a local energy minima, could not fold into the native form, which was characterized by a global energy minimum. The addition of surfactants created folding pathways via the formation of protein-surfactant complexes and thus enabled the conformations that fell into energy trap states to escape from these traps and to form the native proteins. The simulation results also showed that it was necessary to match the hydrophobicity of surfactant to the concentration of denaturant, which was added to control the folding or unfolding of a protein. The surfactants with different hydrophobicity had their own concentration range on assisting protein refolding. All of these simulations agreed well with experimental results reported elsewhere, indicating both the validity of the simulations presented here and the potential application of the simulations for the design of a surfactant on assisting protein refolding.

  1. Structural study of surfactant-dependent interaction with protein

    Energy Technology Data Exchange (ETDEWEB)

    Mehan, Sumit; Aswal, Vinod K., E-mail: vkaswal@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, Joachim [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland)

    2015-06-24

    Small-angle neutron scattering (SANS) has been used to study the complex structure of anionic BSA protein with three different (cationic DTAB, anionic SDS and non-ionic C12E10) surfactants. These systems form very different surfactant-dependent complexes. We show that the structure of protein-surfactant complex is initiated by the site-specific electrostatic interaction between the components, followed by the hydrophobic interaction at high surfactant concentrations. It is also found that hydrophobic interaction is preferred over the electrostatic interaction in deciding the resultant structure of protein-surfactant complexes.

  2. Surfactant protein A and surfactant protein D variation in pulmonary disease

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Husby, Steffen; Holmskov, Uffe

    2007-01-01

    Surfactant proteins A (SP-A) and D (SP-D) have been implicated in pulmonary innate immunity. The proteins are host defense lectins, belonging to the collectin family which also includes mannan-binding lectin (MBL). SP-A and SP-D are pattern-recognition molecules with the lectin domains binding...... lavage and blood have indicated associations with a multitude of pulmonary inflammatory diseases. In addition, accumulating evidence in mouse models of infection and inflammation indicates that recombinant forms of the surfactant proteins are biologically active in vivo and may have therapeutic potential...... in controlling pulmonary inflammatory disease. The presence of the surfactant collectins, especially SP-D, in non-pulmonary tissues, such as the gastrointestinal tract and genital organs, suggest additional actions located to other mucosal surfaces. The aim of this review is to summarize studies on genetic...

  3. Different effects of surfactant proteins B and C - implications for development of synthetic surfactants.

    Science.gov (United States)

    Curstedt, Tore; Johansson, Jan

    2010-06-01

    Treatment of premature newborn rabbits with synthetic surfactants containing a surfactant protein C analogue in a simple phospholipid mixture gives similar tidal volumes as treatment with poractant alfa (Curosurf(R)) but ventilation with a positive end-expiratory pressure (PEEP) is needed for this synthetic surfactant to stabilize the alveoli at end-expiration. The effect on lung gas volumes seems to depend on the structure of the peptide since treatment with a synthetic surfactant containing the 21-residue peptide (LysLeu(4))(4)Lys (KL(4)) gives low lung gas volumes in experiments also performed with PEEP. Surfactant preparations containing both surfactant proteins B and C or their analogues prevent alveolar collapse at end-expiration even if ventilated without PEEP. Treatment of premature newborn rabbits with different natural surfactants indicates that both the lipid composition and the proteins are important in order to stabilize the alveoli at end-expiration. Synthetic surfactants containing two peptides may be able to replace natural surfactants within the near future but more trials need to be performed before any conclusion can be drawn about the ideal composition of this new generation of synthetic surfactants. Copyright 2010 S. Karger AG, Basel.

  4. Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D.

    Directory of Open Access Journals (Sweden)

    Taku Fukuzawa

    Full Text Available Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta(+/+ and Ig-Hepta(-/- mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i balanced synthesis of surfactant lipids and proteins and (ii surfactant secretion, and (iii a stimulating effect on recycling (uptake in response to elevated levels of Sp-D in alveolar space.

  5. Surfactant protein D is proatherogenic in mice

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Madsen, Jens; Kejling, Karin

    2006-01-01

    Surfactant protein D (SP-D) is an important innate immune defense molecule that mediates clearance of pathogens and modulates the inflammatory response. Moreover, SP-D is involved in lipid homeostasis, and pulmonary accumulation of phospholipids has previously been observed in SP-D-deficient (Spd......-alpha was reduced in Spd-/- mice (45% difference). SP-D was proatherogenic in the mouse model used. The effect is likely to be due to the observed disturbances of plasma lipid metabolism and alteration of the inflammatory process, which underlie the reduced susceptibility to atherosclerosis in Spd-/- mice....

  6. Proteins and protein/surfactant mixtures at interfaces in motion

    NARCIS (Netherlands)

    Boerboom, F.J.G.

    2000-01-01

    The research described in this thesis covers a number of aspects of the relation between surface properties and foaming properties of proteins, low molecular surfactants and mixtures thereof. This work is the result of a question of the industrial partners if it is possible to understand

  7. Serum Levels of Surfactant Proteins in Patients with Combined Pulmonary Fibrosis and Emphysema (CPFE.

    Directory of Open Access Journals (Sweden)

    Andriana I Papaioannou

    Full Text Available Emphysema and idiopathic pulmonary fibrosis (IPF present either per se or coexist in combined pulmonary fibrosis and emphysema (CPFE. Serum surfactant proteins (SPs A, B, C and D levels may reflect lung damage. We evaluated serum SP levels in healthy controls, emphysema, IPF, and CPFE patients and their associations to disease severity and survival.122 consecutive patients (31 emphysema, 62 IPF, and 29 CPFE and 25 healthy controls underwent PFTs, ABG-measurements, 6MWT and chest HRCT. Serum levels of SPs were measured. Patients were followed-up for 1-year.SP-A and SP-D levels differed between groups (p = 0.006 and p<0.001 respectively. In post-hoc analysis, SP-A levels differed only between controls and CPFE (p<0.05 and CPFE and emphysema (p<0.05. SP-D differed between controls and IPF or CPFE (p<0.001 for both comparisons. In IPF SP-B correlated to pulmonary function while SP-A, correlated to the Composite Physiological Index (CPI. Controls current smokers had higher SP-A and SP-D levels compared to non-smokers (p = 0.026 and p = 0.023 respectively. SP-D levels were higher in CPFE patients with extended emphysema (p = 0.042. In patients with IPF, SP-B levels at the upper quartile of its range (≥26 ng/mL presented a weak association with reduced survival (p = 0.05.In conclusion, serum SP-A and SP-D levels were higher where fibrosis exists or coexists and related to disease severity, suggesting that serum SPs relate to alveolar damage in fibrotic lungs and may reflect either local overproduction or overleakage. The weak association between high levels of SP-B and survival needs further validation in clinical trials.

  8. Surfactant protein D is proatherogenic in mice

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Madsen, Jens; Kejling, Karin

    2006-01-01

    Surfactant protein D (SP-D) is an important innate immune defense molecule that mediates clearance of pathogens and modulates the inflammatory response. Moreover, SP-D is involved in lipid homeostasis, and pulmonary accumulation of phospholipids has previously been observed in SP-D-deficient (Spd......-/-) mice. Atherogenesis involves both inflammation and lipid deposition, and we investigated the role of SP-D in the development of atherosclerosis. SP-D synthesis was localized to vascular endothelial cells. Atherosclerotic lesion areas were 5.6-fold smaller in the aortic roots in Spd-/- mice compared...... with wild-type C57BL/6N mice on an atherogenic diet. HDL cholesterol (HDL-C) was significantly elevated in Spd-/- mice. Treatment of Spd-/- mice with a recombinant fragment of human SP-D resulted in decreases of HDL-C (21%) as well as total cholesterol (26%), and LDL cholesterol (28%). Plasma TNF...

  9. Surface activity of pulmonary surfactant protein B : from biophysical properties to clinical application

    NARCIS (Netherlands)

    Diemel, Robert Victor

    2002-01-01

    The global aim of our studies was to obtain more information about the mechanisms involved in the action of the hydrophobic surfactant components, with a special attention for SP-B. To reach this goal, many different assays and devices were used, including a pressure driven captive bubble

  10. Surfactant protein A and surfactant protein D variation in pulmonary disease

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Husby, Steffen; Holmskov, Uffe

    2007-01-01

    preferentially to sugars on a broad spectrum of pathogen surfaces and thereby facilitating immune functions including viral neutralization, clearance of bacteria, fungi and apoptotic and necrotic cells, modulation of allergic reactions, and resolution of inflammation. SP-A and SP-D can interact with receptor...... lavage and blood have indicated associations with a multitude of pulmonary inflammatory diseases. In addition, accumulating evidence in mouse models of infection and inflammation indicates that recombinant forms of the surfactant proteins are biologically active in vivo and may have therapeutic potential...... in controlling pulmonary inflammatory disease. The presence of the surfactant collectins, especially SP-D, in non-pulmonary tissues, such as the gastrointestinal tract and genital organs, suggest additional actions located to other mucosal surfaces. The aim of this review is to summarize studies on genetic...

  11. Comparison of surfactant protein B polymorphisms of healthy term newborns with preterm newborns having respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    P.P.R. Lyra

    2007-06-01

    Full Text Available Polymorphisms and mutations in the surfactant protein B (SP-B gene have been associated with the pathogenesis of respiratory distress syndrome (RDS. The objective of the present study was to compare the frequencies of SP-B gene polymorphisms between preterm babies with RDS and healthy term newborns. We studied 50 preterm babies with RDS (inclusion criteria - newborns with RDS and gestational age between 28 and 33 weeks and 6 days, and 100 healthy term newborns. Four SP-B gene polymorphisms were analyzed: A/C at nucleotide -18, C/T at nucleotide 1580, A/G at nucleotide 9306, and G/C at nucleotide 8714, by PCR amplification of genomic DNA and genotyping by cRFLP. The healthy newborns comprised 42 female and 58 male neonates; 39 were white and 61 non-white. The RDS group comprised 21 female and 29 male preterm neonates; 28 were white and 22 non-white. Weight ranged from 640 to 2080 g (mean: 1273 g; mean gestational age was 31 weeks and 2 days (range: 28-33 weeks and 6 days. When white children were analyzed separately, a statistically significant difference in the G/C polymorphism at 8714 was observed between groups (P = 0.028. All other genotype frequencies were similar for both groups when sex and race were analyzed together. Analysis of the SP-B polymorphism G/C at nucleotide 8714 showed that among white neonates the GG genotype was found only in the RDS group at a frequency of 17% and the GC genotype was more frequently found in healthy term newborns. These data demonstrate an association of GG genotype with RDS.

  12. Alpha-1-antitrypsin studies: canine serum and canine surfactant protein

    International Nuclear Information System (INIS)

    Tuttle, W.C.; Slauson, D.O.; Dahlstrom, M.; Gorman, C.

    1974-01-01

    Canine serum alpha-1-antitrypsin was isolated by gel filtration and affinity chromatography and characterized by polyacrylamide gel electrophoresis and immunoelectrophoresis. Measurement of the trypsin inhibitory capacity of the separated protein indicated a ninefold concentration of functional trypsin inhibitor during the isolation procedure. Electrophoresis demonstrated the presence of a single protein with alpha-globulin mobility and a molecular weight near that of human alpha-1-antitrypsin. The trypsin inhibitory capacity of pulmonary surfactant protein from five Beagle dogs was measured, related to total surfactant protein concentration, and compared with similar measurements on whole serum from the same animals. Results indicated a variable concentration of trypsin inhibitor in the canine pulmonary surfactant protein. However, the concentration in the surfactant protein was always significantly higher than that in the corresponding serum sample. Preliminary experiments designed to separate the trypsin inhibitory fraction(s) from the other surfactant proteins by gel filtration chromatography indicated that the trypsin inhibitor was probably a single protein with a molecular weight near that of alpha-1-antitrypsin. (U.S.)

  13. Structural characterisation of human proteinosis surfactant protein A

    DEFF Research Database (Denmark)

    Berg, T.; Leth-Larsen, R.; Holmskov, U.

    2000-01-01

    Human surfactant protein-A (SP-A) has been purified from a proteinosis patient and characterised by a combination of automated Edman degradation and mass spectrometry. The complete protein sequence was characterised. The major part of SP-A was shown to consist of SP-A2 gene product, and only...

  14. Surfactant protein D in atopic dermatitis and psoriasis

    DEFF Research Database (Denmark)

    Hohwy, Thomas; Otkjaer, Kristian; Madsen, Jens

    2006-01-01

    The collectin surfactant protein-D (SP-D) shows antimicrobial and immuno-regulatory properties and has recently been detected in the basal layers of normal human skin. This molecule potentially plays an important role in inflammatory skin diseases and therefore SP-D content and location was exami......The collectin surfactant protein-D (SP-D) shows antimicrobial and immuno-regulatory properties and has recently been detected in the basal layers of normal human skin. This molecule potentially plays an important role in inflammatory skin diseases and therefore SP-D content and location...

  15. Circulating surfactant protein D is decreased in early rheumatoid arthritis

    DEFF Research Database (Denmark)

    Høgh, Silje Vermedal; Lindegaard, Hanne Merete; Sørensen, Grith Lykke

    2008-01-01

    Innate immune system abnormalities, e.g., mannan-binding lectin (MBL) genotype variants, have been demonstrated to modify the disease course of rheumatoid arthritis (RA). Surfactant protein D (SP-D) shares important structural and functional properties with MBL suggesting that SP-D may be an addi......Innate immune system abnormalities, e.g., mannan-binding lectin (MBL) genotype variants, have been demonstrated to modify the disease course of rheumatoid arthritis (RA). Surfactant protein D (SP-D) shares important structural and functional properties with MBL suggesting that SP-D may...

  16. Surfactant Protein A and B Gene Polymorphisms and Risk of Respiratory Distress Syndrome in Late-Preterm Neonates.

    Science.gov (United States)

    Tsitoura, Maria-Eleni I; Stavrou, Eleana F; Maraziotis, Ioannis A; Sarafidis, Kosmas; Athanassiadou, Aglaia; Dimitriou, Gabriel

    2016-01-01

    Newborns delivered late-preterm (between 340/7 and 366/7 weeks of gestation) are at increased risk of respiratory distress syndrome (RDS). Polymorphisms within the surfactant protein (SP) A and B gene have been shown to predispose to RDS in preterm neonates. The aim of this study was to investigate whether specific SP-A and/or SP-B genetic variants are also associated with RDS in infants born late-preterm. This prospective cross-sectional study included 56 late-preterm infants with and 60 without RDS. Specific SP-A1/SP-A2 haplotypes and SP-B Ile131Thr polymorphic alleles were determined in blood specimens using polymerase-chain-reaction and DNA sequencing. The SP-A1 6A4 and the SP-A2 1A5 haplotypes were significantly overrepresented in newborns with RDS compared to controls (OR 2.86, 95%CI 1.20-6.83 and OR 4.68, 95%CI 1.28-17.1, respectively). The distribution of the SP-B Ile131Thr genotypes was similar between the two late-preterm groups. Overall, the SP-A1 6A4 or/and SP-A2 1A5 haplotype was present in 20 newborns with RDS (35.7%), resulting in a 4.2-fold (1.60-11.0) higher probability of RDS in carriers. Multivariable regression analysis revealed that the effect of SP-A1 6A4 and SP-A2 1A5 haplotypes was preserved when adjusting for known risk or protective factors, such as male gender, smaller gestational age, smaller weight, complications of pregnancy, and administration of antenatal corticosteroids. Specific SP-A genetic variants may influence the susceptibility to RDS in late-preterm infants, independently of the effect of other perinatal factors.

  17. Acidic pH triggers conformational changes at the NH2-terminal propeptide of the precursor of pulmonary surfactant protein B to form a coiled coil structure.

    Science.gov (United States)

    Bañares-Hidalgo, A; Pérez-Gil, J; Estrada, P

    2014-07-01

    Pulmonary surfactant protein SP-B is synthesized as a larger precursor, proSP-B. We report that a recombinant form of human SP-BN forms a coiled coil structure at acidic pH. The protonation of a residue with pK=4.8±0.06 is the responsible of conformational changes detected by circular dichroism and intrinsic fluorescence emission. Sedimentation velocity analysis showed protein oligomerisation at any pH condition, with an enrichment of the species compatible with a tetramer at acidic pH. Low 2,2,2,-trifluoroethanol concentration promoted β-sheet structures in SP-BN, which bind Thioflavin T, at acidic pH, whereas it promoted coiled coil structures at neutral pH. The amino acid stretch predicted to form β-sheet parallel association in SP-BN overlaps with the sequence predicted by several programs to form coiled coil structure. A synthetic peptide ((60)W-E(85)) designed from the sequence of the amino acid stretch of SP-BN predicted to form coiled coil structure showed random coil conformation at neutral pH but concentration-dependent helical structure at acidic pH. Sedimentation velocity analysis of the peptide indicated monomeric state at neutral pH (s20, w=0.55S; Mr~3kDa) and peptide association (s20, w=1.735S; Mr=~14kDa) at acidic pH, with sedimentation equilibrium fitting to a Monomer-Nmer-Mmer model with N=6 and M=4 (Mr=14692Da). We propose that protein oligomerisation through coiled-coil motifs could then be a general feature in the assembly of functional units in saposin-like proteins in general and in the organization of SP-B in a functional surfactant, in particular. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Small-angle neutron scattering study of structure and interaction of nanoparticle, protein, and surfactant complexes.

    Science.gov (United States)

    Mehan, Sumit; Chinchalikar, Akshay J; Kumar, Sugam; Aswal, Vinod K; Schweins, Ralf

    2013-09-10

    Small-angle neutron scattering (SANS) measurements have been carried out from the multicomponent system composed of Ludox HS40 silica nanoparticle, bovine serum albumin (BSA) protein, and sodium dodecyl sulfate (SDS) surfactant in an aqueous system under the solution condition that all the components are negatively charged. Although the components are similarly charged, strong structural evolutions among them have been observed. The complexes of different components in pairs (nanoparticle-protein, nanoparticle-surfactant, and protein-surfactant) have been examined to correlate the role of each component in the three-component nanoparticle-protein-surfactant system. The nanoparticle-protein system shows depletion interaction induced aggregation of nanoparticles in the presence of protein. Both nanoparticle and surfactant coexist individually in a nanoparticle-surfactant system. In the case of a protein-surfactant system, the cooperative binding of surfactant with protein leads to micelle-like clusters of surfactant formed along the unfolded protein chain. The structure of the three-component (nanoparticle-protein-surfactant) system is found to be governed by the synergetic effect of nanoparticle-protein and protein-surfactant interactions. The nanoparticle aggregates coexist with the structures of protein-surfactant complex in the three-component system. The nanoparticle aggregation as well as unfolding of protein is enhanced in this system as compared to the corresponding two-component systems.

  19. Genetic and environmental influences of surfactant protein D serum levels

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Hjelmborg, Jacob v. B.; Kyvik, Kirsten Ohm

    2006-01-01

    The collectin surfactant protein D (SP-D) is an important component of the pulmonary innate immune system, but SP-D is also present on extrapulmonary epithelial surfaces and in serum, where it has been used as a biomarker for pulmonary disease states. In this study, we investigate the mechanisms...

  20. Linking surfactant protein SP-D and IL-13

    DEFF Research Database (Denmark)

    Qaseem, Asif S; Sonar, Sanchaita; Mahajan, Lakshna

    2012-01-01

    Surfactant protein D (SP-D) is an innate immune molecule that plays a protective role against lung infection, allergy, asthma and inflammation. In vivo experiments with murine models have shown that SP-D can protect against allergic challenge via a range of mechanisms including inhibition...

  1. Genetic and environmental influences of surfactant protein D serum levels

    DEFF Research Database (Denmark)

    Sorensen, G.L.; Hjelmborg, J.V.; Kyvik, K.O.

    2006-01-01

    The collectin surfactant protein D (SP-D) is an important component of the pulmonary innate immune system, but SP-D is also present on extrapulmonary epithelial surfaces and in serum, where it has been used as a biomarker for pulmonary disease states. In this study, we investigate the mechanisms ...

  2. C-reactive protein increases membrane fluidity and distorts lipid lateral organization of pulmonary surfactant. Protective role of surfactant protein A

    DEFF Research Database (Denmark)

    Saenz, Alejandra; Lopez-Sanchez, Almudena; Mojica-Lazaro, Jonas

    2010-01-01

    intratracheal instillation of CRP into rat lungs. Insertion of CRP into surfactant membranes was investigated through monolayer techniques. The effect of CRP on membrane structure was studied through differential scanning calorimetry and fluorescence spectroscopy and microscopy using large and giant unilamellar......The purpose of this study was to investigate how surfactant membranes can be perturbed by C-reactive protein (CRP) and whether surfactant protein A (SP-A) might overcome CRP-induced surfactant membrane alterations. The effect of CRP on surfactant surface adsorption was evaluated in vivo after...... vesicles. Our results indicate that CRP inserts into surfactant membranes and drastically increases membrane fluidity, resulting in surfactant inactivation. At 10% CRP/phospholipid weight ratio, CRP causes disappearance of liquid-ordered/liquid-disordered phase coexistence distinctive of surfactant...

  3. Animal derived surfactant extract versus protein free synthetic surfactant for the prevention and treatment of respiratory distress syndrome.

    Science.gov (United States)

    Ardell, Stephanie; Pfister, Robert H; Soll, Roger

    2015-08-24

    A wide variety of surfactant preparations have been developed and tested including synthetic surfactants and surfactants derived from animal sources. Although clinical trials have demonstrated that both synthetic surfactant and animal derived surfactant preparations are effective, comparison in animal models has suggested that there may be greater efficacy of animal derived surfactant products, perhaps due to the protein content of animal derived surfactant. To compare the effect of animal derived surfactant to protein free synthetic surfactant preparations in preterm infants at risk for or having respiratory distress syndrome (RDS). Searches were updated of the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2014), PubMed, CINAHL and EMBASE (1975 through November 2014). All languages were included. Randomized controlled trials comparing administration of protein free synthetic surfactants to administration of animal derived surfactant extracts in preterm infants at risk for or having respiratory distress syndrome were considered for this review. Data collection and analysis were conducted according to the standards of the Cochrane Neonatal Review Group. Fifteen trials met the inclusion criteria. The meta-analysis showed that the use of animal derived surfactant rather than protein free synthetic surfactant resulted in a significant reduction in the risk of pneumothorax [typical relative risk (RR) 0.65, 95% CI 0.55 to 0.77; typical risk difference (RD) -0.04, 95% CI -0.06 to -0.02; number needed to treat to benefit (NNTB) 25; 11 studies, 5356 infants] and a marginal reduction in the risk of mortality (typical RR 0.89, 95% CI 0.79 to 0.99; typical RD -0.02, 95% CI -0.04 to -0.00; NNTB 50; 13 studies, 5413 infants).Animal derived surfactant was associated with an increase in the risk of necrotizing enterocolitis [typical RR 1.38, 95% CI 1.08 to 1.76; typical RD 0.02, 95% CI 0.01 to 0.04; number needed to treat to harm (NNTH) 50; 8

  4. Refolding of SDS-Unfolded Proteins by Nonionic Surfactants.

    Science.gov (United States)

    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.

  5. Surfactant protein-B 121ins2 heterozygosity, reduced pulmonary function, and chronic obstructive pulmonary disease in smokers

    DEFF Research Database (Denmark)

    Bækvad-Hansen, Marie; Dahl, Morten; Tybjaerg-Hansen, Anne

    2010-01-01

    Hereditary surfactant protein-B deficiency is an autosomal recessive disorder that causes fatal respiratory distress syndrome in newborns. Seventy percent of the cases of hereditary surfactant protein-B deficiency are caused by homozygosity for the 121ins2 mutation in the surfactant protein-B gen....... Individuals heterozygous for this mutation have partial absence of surfactant protein-B and could be at risk of lung disease when exposed to additional risk factors for impaired surfactant function such as tobacco smoking....

  6. Surfactant protein-D and pulmonary host defense

    Directory of Open Access Journals (Sweden)

    Crouch Erika C

    2000-08-01

    Full Text Available Abstract Surfactant protein-D (SP-D participates in the innate response to inhaled microorganisms and organic antigens, and contributes to immune and inflammatory regulation within the lung. SP-D is synthesized and secreted by alveolar and bronchiolar epithelial cells, but is also expressed by epithelial cells lining various exocrine ducts and the mucosa of the gastrointestinal and genitourinary tracts. SP-D, a collagenous calcium-dependent lectin (or collectin, binds to surface glycoconjugates expressed by a wide variety of microorganisms, and to oligosaccharides associated with the surface of various complex organic antigens. SP-D also specifically interacts with glycoconjugates and other molecules expressed on the surface of macrophages, neutrophils, and lymphocytes. In addition, SP-D binds to specific surfactant-associated lipids and can influence the organization of lipid mixtures containing phosphatidylinositol in vitro. Consistent with these diverse in vitro activities is the observation that SP-D-deficient transgenic mice show abnormal accumulations of surfactant lipids, and respond abnormally to challenge with respiratory viruses and bacterial lipopolysaccharides. The phenotype of macrophages isolated from the lungs of SP-D-deficient mice is altered, and there is circumstantial evidence that abnormal oxidant metabolism and/or increased metalloproteinase expression contributes to the development of emphysema. The expression of SP-D is increased in response to many forms of lung injury, and deficient accumulation of appropriately oligomerized SP-D might contribute to the pathogenesis of a variety of human lung diseases.

  7. Modifications in structure and interaction of nanoparticle-protein-surfactant complexes in electrolyte solution

    Science.gov (United States)

    Mehan, Sumit; Kumar, S.; Aswal, V. K.; Schweins, R.

    2016-05-01

    SANS experiments of three-component system of anionic silica nanoparticles, anionic BSA protein and anionic SDS surfactants have been carried out without and with electrolyte in aqueous solution. In both the cases, the interaction of surfactant with protein results in formation of bead-necklace structure of protein-surfactant complexes in solution. These protein-surfactant complexes interact very differently with nanoparticles in absence and presence of electrolyte. In absence of electrolyte, nanoparticles remain in dispersed phase in solution, whereas with the addition of electrolyte the nanoparticles fractal aggregates are formed. SANS describes the phase behavior to be governed by competition of electrostatic and depletion interactions among the components solution.

  8. Essential Regulation of Lung Surfactant Homeostasis by the Orphan G Protein-Coupled Receptor GPR116

    Directory of Open Access Journals (Sweden)

    Mi Young Yang

    2013-05-01

    Full Text Available GPR116 is an orphan seven-pass transmembrane receptor whose function has been unclear. Global disruption of the Gpr116 gene in mice revealed an unexpected, critical role for this receptor in lung surfactant homeostasis, resulting in progressive accumulation of surfactant lipids and proteins in the alveolar space, labored breathing, and a reduced lifespan. GPR116 expression analysis, bone marrow transplantation studies, and characterization of conditional knockout mice revealed that GPR116 expression in ATII cells is required for maintaining normal surfactant levels. Aberrant packaging of surfactant proteins with lipids in the Gpr116 mutant mice resulted in compromised surfactant structure, function, uptake, and processing. Thus, GPR116 plays an indispensable role in lung surfactant homeostasis with important ramifications for the understanding and treatment of lung surfactant disorders.

  9. Spontaneous surface self-assembly in protein-surfactant mixtures: interactions between hydrophobin and ethoxylated polysorbate surfactants.

    Science.gov (United States)

    Tucker, Ian M; Petkov, Jordan T; Penfold, Jeffrey; Thomas, Robert K; Li, Peixun; Cox, Andrew R; Hedges, Nick; Webster, John R P

    2014-05-08

    The synergistic interactions between certain ethoxylated polysorbate nonionic surfactants and the protein hydrophobin result in spontaneous self-assembly at the air-water interface to form layered surface structures. The surface structures are characterized using neutron reflectivity. The formation of the layered surface structures is promoted by the hydrophobic interaction between the polysorbate alkyl chain and the hydrophobic patch on the surface of the globular hydrophobin and the interaction between the ethoxylated sorbitan headgroup and hydrophilic regions of the protein. The range of the ethoxylated polysorbate concentrations over which the surface ordering occurs is a maximum for the more hydrophobic surfactant polyoxyethylene(8) sorbitan monostearate. The structures at the air-water interface are accompanied by a profound change in the wetting properties of the solution on hydrophobic substrates. In the absence of the polysorbate surfactant, hydrophobin wets a hydrophobic surface, whereas the hydrophobin/ethoxylated polysorbate mixtures where multilayer formation occurs result in a significant dewetting of hydrophobic surfaces. The spontaneous surface self-assembly for hydrophobin/ethoxylated polysorbate surfactant mixtures and the changes in surface wetting properties provide a different insight into protein-surfactant interactions and potential for manipulating surface and interfacial properties and protein surface behavior.

  10. Observation of two different fractal structures in nanoparticle, protein and surfactant complexes

    International Nuclear Information System (INIS)

    Mehan, Sumit; Kumar, Sugam; Aswal, V. K.

    2014-01-01

    Small angle neutron scattering has been carried out from a complex of nanoparticle, protein and surfactant. Although all the components are similarly (anionic) charged, we have observed strong interactions in their complex formation. It is characterized by the coexistence of two different mass fractal structures. The first fractal structure is originated from the protein and surfactant interaction and second from the depletion effect of first fractal structure leading the nanoparticle aggregation. The fractal structure of protein-surfactant complex represents to bead necklace structure of micelle-like clusters of surfactant formed along the unfolded protein chain. Its fractal dimension depends on the surfactant to protein ratio (r) and decreases with the increase in r. However, fractal dimension of nanoparticle aggregates in nanoparticle-protein complex is found to be independent of protein concentration and governed by the diffusion limited aggregation like morphology

  11. Interactions between Surfactants in Solution and Electrospun Protein Fibers: Effects on Release Behavior and Fiber Properties

    DEFF Research Database (Denmark)

    Boutrup Stephansen, Karen; García-Díaz, María; Jessen, Flemming

    2016-01-01

    , and drug delivery. In the present study, we present a systematic investigation of how surfactants and proteins, as physiologically relevant components, interact with insulin-loaded fish sarcoplasmic protein (FSP) electrospun fibers (FSP-Ins fibers) in solution and thereby affect fiber properties...... such as accessible surface hydrophilicity, physical stability, and release characteristics of an encapsulated drug. Interactions between insulin-loaded protein fibers and five anionic surfactants (sodium taurocholate, sodium taurodeoxycholate, sodium glycocholate, sodium glycodeoxycholate, and sodium dodecyl sulfate......), a cationic surfactant (benzalkonium chloride), and a neutral surfactant (Triton X-100) were studied. The anionic surfactants increased the insulin release in a concentration-dependent manner, whereas the neutral surfactant had no significant effect on the release. Interestingly, only minute amounts...

  12. Surfactant protein D in the female genital tract

    DEFF Research Database (Denmark)

    Leth-Larsen, Rikke; Floridon, C; Nielsen, O

    2004-01-01

    Surfactant protein D (SP-D) plays a role in innate immunity against various pathogens and in vivo studies have demonstrated that SP-D also has anti-inflammatory properties. SP-D was originally demonstrated in alveolar type II cells, but recent studies have shown extrapulmonary expression of SP-D...... indicating a systemic role for the protein. This study describes the presence of SP-D in the female genital tract, the placenta and in amniotic fluid using immunohistochemistry and enzyme-linked immunosorbent assay. SP-D was observed in cells lining surface epithelium and secretory glands in the vagina......, cervix, uterus, fallopian tubes and ovaries. In the placenta, SP-D was seen in all villous and extravillous trophoblast subpopulations. Endometrial presence of SP-D in non-pregnant women varied according to stage of the menstrual cycle and was up-regulated towards the secretory phase. It is suggested...

  13. Circulating surfactant protein D is decreased in systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Hoegh, Silje Vermedal; Voss, Anne; Sørensen, Grith Lykke

    2009-01-01

    -1118) in patients and 1068 ng/ml (95% CI 901-1246) in controls (p = 0.0004). Circulating SP-D did not differ significantly in patients with high, intermediate, or low SLE disease activity. Similarly, SP-D did not correlate with C-reactive protein, erythrocyte sedimentation rate, and anti-dsDNA seropositivity......OBJECTIVE: Deficiencies of innate immune molecules like mannan binding lectin (MBL) have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Surfactant protein D (SP-D) and MBL belong to the same family of innate immune molecules - the collectins, which share important...... structural and functional properties. We aimed to compare concentrations of serum SP-D in patients with SLE and in healthy controls, and to investigate if SP-D is associated with selected disease indicators. We investigated the possible association of the Met11Thr polymorphism with disease, since...

  14. DECREASED PRODUCTION OF SURFACTANT PROTEINS AFTER DIESEL EXHAUST EXPOSURE INCREASES SUSCEPTIBILITY TO INFLUENZA INFECTION

    Science.gov (United States)

    Pulmonary surfactant proteins A and D (SP-A and SP-D), termed collectins, enhance the opsonization of foreign particles and pathogens by phagocytic cells. Inhaled pollutants such as diesel exhaust (DE) have a possible role in suppressing the production of surfactant proteins whic...

  15. Interfacial rheological properties of adsorbed protein layers and surfactants: a review

    NARCIS (Netherlands)

    Bos, M.A.; Vliet, van T.

    2001-01-01

    Proteins and low molecular weight (LMW) surfactants are widely used for the physical stabilisation of many emulsions and foam based food products. The formation and stabilisation of these emulsions and foams depend strongly on the interfacial properties of the proteins and the LMW surfactants.

  16. Interfacial rheological properties of adsorbed protein layers and surfactants : a review

    NARCIS (Netherlands)

    Bos, M.A.; Vliet, T. van

    2001-01-01

    Proteins and low molecular weight (LMW) surfactants are widely used for the physical stabilisation of many emulsions and foam based food products. The formation and stabilisation of these emulsions and foams depend strongly on the interfacial properties of the proteins and the LMW surfactants.

  17. Neat Protein-Polymer Surfactant Bioconjugates as Universal Solvents.

    Science.gov (United States)

    Mukhopadhyay, Anasua; Das, Tarasankar; Datta, Anindya; Sharma, Kamendra P

    2018-02-23

    Solvents, particularly those having low volatility, are of great interest for the biocatalytic synthesis of utility chemicals and fuels. We show novel and universal solvent-like properties of a neat and water-less polymer surfactant-bovine serum albumin (BSA) conjugated material (WL-PSpBSA). This highly viscous, nonvolatile material behaves as a liquid above its solid-liquid transition temperature (∼25-27 °C) and can be used as a solvent for variety of completely dry solutes of different sizes and surface chemistries. We show using a combination of optical microscopy and steady -state and time-resolved fluorescence spectroscopy that dry and powdered dyes (hydrophobic Coumarin 153 (C153)), enzymes (α-chymotrypsin (α-Chy)), or even 1 μm microparticles (diffusion coefficient ca. three orders slower than C153), can be solubilized and completely dispersed in the WL-PSpBSA solvent above 25 °C. While C153, irrespective of its mode of addition to WL-PSpBSA, binds similarly to BSA, α-Chy can be stabilized and activated to perform its hydrolysis function, even at 100 °C. This work therefore provides insights into the form of universal solvent characteristic property for this new class of nonaqueous, nonvolatile, biodegradable protein-polymer surfactant-based conjugated materials and suggests potential new avenues that can have a huge impact on biocatalysis, bionanotechnology, drug delivery, and other applications.

  18. Surfactant protein-B 121ins2 heterozygosity, reduced pulmonary function, and chronic obstructive pulmonary disease in smokers

    DEFF Research Database (Denmark)

    Bækvad-Hansen, Marie; Dahl, Morten; Tybjaerg-Hansen, Anne

    2010-01-01

    Hereditary surfactant protein-B deficiency is an autosomal recessive disorder that causes fatal respiratory distress syndrome in newborns. Seventy percent of the cases of hereditary surfactant protein-B deficiency are caused by homozygosity for the 121ins2 mutation in the surfactant protein-B gene...

  19. "SP-G", a putative new surfactant protein--tissue localization and 3D structure.

    Directory of Open Access Journals (Sweden)

    Felix Rausch

    Full Text Available Surfactant proteins (SP are well known from human lung. These proteins assist the formation of a monolayer of surface-active phospholipids at the liquid-air interface of the alveolar lining, play a major role in lowering the surface tension of interfaces, and have functions in innate and adaptive immune defense. During recent years it became obvious that SPs are also part of other tissues and fluids such as tear fluid, gingiva, saliva, the nasolacrimal system, and kidney. Recently, a putative new surfactant protein (SFTA2 or SP-G was identified, which has no sequence or structural identity to the already know surfactant proteins. In this work, computational chemistry and molecular-biological methods were combined to localize and characterize SP-G. With the help of a protein structure model, specific antibodies were obtained which allowed the detection of SP-G not only on mRNA but also on protein level. The localization of this protein in different human tissues, sequence based prediction tools for posttranslational modifications and molecular dynamic simulations reveal that SP-G has physicochemical properties similar to the already known surfactant proteins B and C. This includes also the possibility of interactions with lipid systems and with that, a potential surface-regulatory feature of SP-G. In conclusion, the results indicate SP-G as a new surfactant protein which represents an until now unknown surfactant protein class.

  20. Surfactant effects on protein structure examined by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Loo, R. R.; Dales, N.; Andrews, P. C.

    1994-01-01

    Electrospray ionization mass spectrometry (ESI-MS) has proven to be a useful tool for examining noncovalent complexes between proteins and a variety of ligands. It has also been used to distinguish between denatured and refolded forms of proteins. Surfactants are frequently employed to enhance solubilization or to modify the tertiary or quaternary structure of proteins, but are usually considered incompatible with mass spectrometry. A broad range of ionic, nonionic, and zwitterionic surfactants was examined to characterize their effects on ESI-MS and on protein structure under ESI-MS conditions. Solution conditions studied include 4% acetic acid/50% acetonitrile/46% H2O and 100% aqueous. Of the surfactants examined, the nonionic saccharides, such as n-dodecyl-beta-D-glucopyranoside, at 0.1% to 0.01% (w/v) concentrations, performed best, with limited interference from chemical background and adduct formation. Under the experimental conditions used, ESI-MS performance in the presence of surfactants was found to be unrelated to critical micelle concentration. It is demonstrated that surfactants can affect both the tertiary and quaternary structures of proteins under conditions used for ESI-MS. However, several of the surfactants caused significant shifts in the charge-state distributions, which appeared to be independent of conformational effects. These observations suggest that surfactants, used in conjunction with ESI-MS, can be useful for protein structure studies, if care is used in the interpretation of the results. PMID:7703844

  1. Purification, characterization and immunolocalization of porcine surfactant protein D

    DEFF Research Database (Denmark)

    Sørensen, C.M.; Nielsen, Ove Lilholm; Willis, A.

    2005-01-01

    in a dose and Ca2+-dependent manner with a saccharide specificity similar to rat and human SP-D. The purified protein was used for the production of a monoclonal anti-pSP-D antibody. The antibody reacted specifically with pSP-D in the reduced and unreduced state when analysed by Western blotting......Surfactant protein D (SP-D) is a collectin believed to play an important role in innate immunity. SP-D is characterized by having a collagen-like domain and a carbohydrate recognition domain (CRD), which has a specific Ca2+-dependent specificity for saccharides and thus the ability to bind complex...... glycoconjugates on micro-organisms. This paper describes the tissue immunolocalization of porcine SP-D (pSP-D) in normal slaughter pigs using a monoclonal antibody raised against purified pSP-D. Porcine SP-D was purified from porcine bronchoalveolar lavage (BAL) by maltose-agarose and immunoglobulin M affinity...

  2. Association of surfactant protein-d with obesity

    International Nuclear Information System (INIS)

    Jawed, S.

    2016-01-01

    Obesity is associated with inflammatory diseases and obese individual's poses high risk for infections. Surfactant protein D (SP-D) is an important regulator of immunity and inflammation. Latest studies have suggested that it is also involved in lipid homeostasis and obese subjects have decrease concentration of SPD as compared to normal weight peoples. The aim of the current study was to elucidate the relationship among serum SP-D and BMI. Method: This cross sectional study was performed at Dow University of health sciences (DUHS), Karachi. We analysed 90 obese and non-obese subjects for serum SP-D concentration. SP-D was estimated by ELISA. Data was analysed by SPSS 16. Mean SP-D level and demographical variables between the groups were compared by t test, Associations of SP-D with BMI investigated by regression analysis. Results: obese subjects have significant lower levels of Serum SP-D than non-obese and negatively associated with BMI in both genders (p=0.000). Conclusion: This study concluded that obese subjects have lower concentration of SP-D as compare to non-obese and there is an inverse association between the SP-D and BMI. (author)

  3. Interactions between Surfactants in Solution and Electrospun Protein Fibers: Effects on Release Behavior and Fiber Properties.

    Science.gov (United States)

    Stephansen, Karen; García-Díaz, María; Jessen, Flemming; Chronakis, Ioannis S; Nielsen, Hanne M

    2016-03-07

    Intermolecular interaction phenomena occurring between endogenous compounds, such as proteins and bile salts, and electrospun compounds are so far unreported, despite the exposure of fibers to such biorelevant compounds when applied for biomedical purposes, e.g., tissue engineering, wound healing, and drug delivery. In the present study, we present a systematic investigation of how surfactants and proteins, as physiologically relevant components, interact with insulin-loaded fish sarcoplasmic protein (FSP) electrospun fibers (FSP-Ins fibers) in solution and thereby affect fiber properties such as accessible surface hydrophilicity, physical stability, and release characteristics of an encapsulated drug. Interactions between insulin-loaded protein fibers and five anionic surfactants (sodium taurocholate, sodium taurodeoxycholate, sodium glycocholate, sodium glycodeoxycholate, and sodium dodecyl sulfate), a cationic surfactant (benzalkonium chloride), and a neutral surfactant (Triton X-100) were studied. The anionic surfactants increased the insulin release in a concentration-dependent manner, whereas the neutral surfactant had no significant effect on the release. Interestingly, only minute amounts of insulin were released from the fibers when benzalkonium chloride was present. The FSP-Ins fibers appeared dense after incubation with this cationic surfactant, whereas high fiber porosity was observed after incubation with anionic or neutral surfactants. Contact angle measurements and staining with the hydrophobic dye 8-anilino-1-naphthalenesulfonic acid indicated that the FSP-Ins fibers were hydrophobic, and showed that the fiber surface properties were affected differently by the surfactants. Bovine serum albumin also affected insulin release in vitro, indicating that also proteins may affect the fiber performance in an in vivo setting.

  4. How chain length and charge affect surfactant denaturation of acyl coenzyme a binding protein (ACBP)

    DEFF Research Database (Denmark)

    Andersen, Kell; Otzen, Daniel

    2009-01-01

    Using intrinsic tryptophan fluorescence, equilibria and kinetics of unfolding of acyl coenzyme A binding protein (ACBP) have been investigated in sodium alkyl sulfate surfactants of different chain length (8-16 carbon atoms) and with different proportions of the nonionic surfactant dodecyl...... maltoside (DDM). The aim has been to determine how surfactant chain length and micellar charge affect the denaturation mechanism. ACBP denatures in two steps irrespective of surfactant chain length, but with increasing chain length, the potency of the denaturant rises more rapidly than the critical micelle...... constants increases linearly with denaturant concentration below the cmc but declines at higher concentrations. Both shortening chain length and decreasing micellar charge reduce the overall kinetics of unfolding and makes the dependence of unfolding rate constants on surfactant concentration more complex...

  5. Bronchoalveolar lavage fluid surfactant protein-A and surfactant protein-D are inversely related to inflammation in early cystic fibrosis

    NARCIS (Netherlands)

    Noah, TL; Murphy, PC; Alink, JJ; Leigh, MW; Hull, WM; Stahlman, MT; Whitsett, JA

    2003-01-01

    The pulmonary collectins surfactant protein (SP)-A and SP-D play important roles in innate lung defense, enhancing opsonization of microbes and limiting lung inflammatory responses. To quantify relationships among collectins, bacteria, and inflammation in early cystic fibrosis (CF) airway

  6. Surfactant proteins gene variants in premature newborn infants with severe respiratory distress syndrome.

    Science.gov (United States)

    Somaschini, Marco; Presi, Silvia; Ferrari, Maurizio; Vergani, Barbara; Carrera, Paola

    2017-12-19

    Genetic surfactant dysfunction causes respiratory failure in term and near-term newborn infants, but little is known of such condition in prematures. We evaluated genetic surfactant dysfunction in premature newborn infants with severe RDS. A total of 68 preterm newborn infants with gestational age ≤32 weeks affected by unusually severe RDS were analysed for mutations in SFTPB, SFTPC and ABCA3. Therapies included oxygen supplementation, nasal CPAP, different modalities of ventilatory support, administration of exogenous surfactant, inhaled nitric oxide and steroids. Molecular analyses were performed on genomic DNA extracted from peripheral blood and Sanger sequencing of whole gene coding regions and intron junctions. In one case histology and electron microscopy on lung tissue was performed. Heterozygous previously described rare or novel variants in surfactant proteins genes ABCA3, SFTPB and SFTPC were identified in 24 newborn infants. In total, 11 infants died at age of 2 to 6 months. Ultrastructural analysis of lung tissue of one infant showed features suggesting ABCA3 dysfunction. Rare or novel genetic variants in genes encoding surfactant proteins were identified in a large proportion (35%) of premature newborn infants with particularly severe RDS. We speculate that interaction of developmental immaturity of surfactant production in association with abnormalities of surfactant metabolism of genetic origin may have a synergic worsening phenotypic effect.

  7. Comparative evaluation of heterologous production systems for recombinant pulmonary surfactant protein D

    Directory of Open Access Journals (Sweden)

    Daniela eSalgado

    2014-12-01

    Full Text Available Commercial surfactant products derived from animal lungs are used for the treatment of respiratory diseases in premature neonates. These products contain lipids and the hydrophobic surfactant proteins B and C, which help to lower the surface tension in the lungs. Surfactant products are less effective when pulmonary diseases involve inflammatory complications because two hydrophilic surfactant proteins (A and D are lost during the extraction process, yet surfactant protein D (SP-D is a component of the innate immune system that helps to reduce lung inflammation. The performance of surfactant products could therefore be improved by supplementing them with an additional source of SP-D. Recombinant SP-D is produced in mammalian cells and bacteria (Escherichia coli, and also experimentally in the yeast Pichia pastoris. Mammalian cells produce full-size SP-D, but the yields are low and the cost of production is high. In contrast, bacteria produce a truncated form of SP-D, which is active in vitro and in vivo, and higher yields can be achieved at a lower cost. We compare the efficiency of production of recombinant SP-D in terms of the total yields achieved in each system and the amount of SP-D needed to meet the global demand for the treatment of pulmonary diseases, using respiratory distress syndrome as a case study.

  8. Elevated Surfactant Protein Levels and Increased Flow of Cerebrospinal Fluid in Cranial Magnetic Resonance Imaging.

    Science.gov (United States)

    Schob, Stefan; Weiß, Alexander; Surov, Alexey; Dieckow, Julia; Richter, Cindy; Pirlich, Mandy; Horvath-Rizea, Diana; Härtig, Wolfgang; Hoffmann, Karl-Titus; Krause, Matthias; Quäschling, Ulf

    2017-12-27

    Surfactant proteins (SPs) are a multifunctional group of proteins, responsible for the regulation of rheological properties of body fluids, host defense, and cellular waste clearance. Their concentrations are changed in cerebrospinal fluid (CSF) of patients suffering from communicating hydrocephalus. Hydrocephalic conditions are accompanied by altered CSF flow dynamics; however, the association of CSF-SP concentrations and CSF flow has not yet been investigated. Hence, the aim of this study was to evaluate the association between SP concentrations in the CSF and marked CSF flow phenomena at different anatomical landmarks of CSF spaces. Sixty-one individuals (15 healthy subjects and 46 hydrocephalus patients) were included in this study. CSF specimens were analyzed for SP-A, SP-B, SP-C, and SP-D concentrations by the use of enzyme-linked immunosorbent assays (ELISA). CSF flow was evaluated in axial T2_turbo inversion recovery magnitude (TIRM)-weighted and sagittal T2-weighted magnetic resonance imaging sections using a 4-grade scale (1-no flow, 2-subtle flow, 3-moderate flow, and 4-strong flow). CSF-SP concentrations (mean ± standard deviation) of the overall collective were as follows: SP-A = 0.73 ± 0.58 ng/ml, SP-B = 0.17 ± 0.93 ng/ml, SP-C = 0.95 ± 0.75 ng/ml, and SP-D = 7.43 ± 5.17 ng/ml. The difference between healthy controls and hydrocephalic patients regarding CSF concentrations of SP-A (0.34 ± 0.22 vs. 0.81 ± 0.59 ng/ml) and SP-C (0.48 ± 0.29 vs. 1.10 ± 0.79 ng/ml) revealed to be statistically significant as calculated by means of ANOVA (p values of 0.022 and 0.007, respectively). CSF flow voids were detectable at all investigated landmarks of the CSF spaces (foramina of Monro, third ventricle, mesencephalic aqueduct, prepontine cistern, fourth ventricle, cisterna magna, and craniocervical junction). CSF flow voids, reported as mean ± standard deviation, revealed to be significantly increased

  9. Stable intermediates determine proteins' primary unfolding sites in the presence of surfactants

    DEFF Research Database (Denmark)

    Petersen, Steen Vang; Andersen, Kell kleiner; Enghild, Jan J.

    2009-01-01

    Despite detailed knowledge of the overall structural changes and stoichiometries of surfactant binding, little is known about which protein regions constitute the preferred sites of attack for initial unfolding. Here we have exposed three proteins to limited proteolysis at anionic (SDS) and catio......Despite detailed knowledge of the overall structural changes and stoichiometries of surfactant binding, little is known about which protein regions constitute the preferred sites of attack for initial unfolding. Here we have exposed three proteins to limited proteolysis at anionic (SDS......) and cationic (DTAC) surfactant concentrations corresponding to specific conformational transitions, using the surfactant-robust broad-specificity proteases Savinase and Alcalase. Cleavage sites are identified by SDS-PAGE and N-terminal sequencing. We observe well-defined cleavage fragments, which suggest......, cleavage sites can be rationalized from the structure of the protein's folding transition state and the position of loops in the native state. Nevertheless, they are more sensitive to choice of surfactant and protease, probably reflecting a heterogeneous and fluctuating ensemble of partially unfolded...

  10. Two Mutations in Surfactant Protein C Gene Associated with Neonatal Respiratory Distress

    Directory of Open Access Journals (Sweden)

    Anna Tarocco

    2015-01-01

    Full Text Available Multiple mutations of surfactant genes causing surfactant dysfunction have been described. Surfactant protein C (SP-C deficiency is associated with variable clinical manifestations ranging from neonatal respiratory distress syndrome to lethal lung disease. We present an extremely low birth weight male infant with an unusual course of respiratory distress syndrome associated with two mutations in the SFTPC gene: C43-7G>A and 12T>A. He required mechanical ventilation for 26 days and was treated with 5 subsequent doses of surfactant with temporary and short-term efficacy. He was discharged at 37 weeks of postconceptional age without any respiratory support. During the first 16 months of life he developed five respiratory infections that did not require hospitalization. Conclusion. This mild course in our patient with two mutations is peculiar because the outcome in patients with a single SFTPC mutation is usually poor.

  11. Species Differences in the Carbohydrate Binding Preferences of Surfactant Protein D

    DEFF Research Database (Denmark)

    Crouch, Erika C.; Smith, Kelly; McDonald, Barbara

    2006-01-01

    Interactions of surfactant protein D (SP-D) with micro-organisms and organic antigens involve binding to the trimeric neck plus carbohydrate recognition domain (neck+CRD). In these studies, we compared the ligand binding of homologous human, rat, and mouse trimeric neck+CRD fusion proteins, each...

  12. Cloning of gp-340, a putative opsonin receptor for lung surfactant protein D

    DEFF Research Database (Denmark)

    Holmskov, U; Mollenhauer, J; Madsen, J

    1999-01-01

    Surfactant protein D (SP-D) is an oligomeric C type lectin that promotes phagocytosis by binding to microbial surface carbohydrates. A 340-kDa glycoprotein (gp-340) has been shown to bind SP-D in the presence of calcium but does so independently of carbohydrate recognition. This protein exists both...

  13. Selective labeling of pulmonary surfactant protein SP-C in organic solution

    DEFF Research Database (Denmark)

    Plasencia, I; Cruz, A; López-Lacomba, J L

    2001-01-01

    Pulmonary surfactant protein SP-C has been isolated from porcine lungs and treated with dansyl isothiocyanate in chloroform:methanol 2:1 (v/v) solutions,under conditions optimized to introduce a single dansyl group covalently attached to the N-terminalamine group of the protein without loss of its...

  14. Species Differences in the Carbohydrate Binding Preferences of Surfactant Protein D

    DEFF Research Database (Denmark)

    Crouch, Erika C.; Smith, Kelly; McDonald, Barbara

    2006-01-01

    Interactions of surfactant protein D (SP-D) with micro-organisms and organic antigens involve binding to the trimeric neck plus carbohydrate recognition domain (neck+CRD). In these studies, we compared the ligand binding of homologous human, rat, and mouse trimeric neck+CRD fusion proteins, each ...

  15. Surfactant Proteins A, B, C and D in the Human Nasal Airway

    DEFF Research Database (Denmark)

    Gaunsbaek, Maria Q; Kjeldsen, Anette D; Svane-Knudsen, Viggo

    2014-01-01

    Aims: To investigate the presence of surfactant protein (SP) A, B, C and D in nasal airways and to determine whether the proteins exert their main functions in nasal secretions or in the deeper layers of the nasal mucosa. Methods: Volunteers were recruited from the Department of ENT Head and Neck...

  16. Alveolar type II cell transplantation restores pulmonary surfactant protein levels in lung fibrosis.

    Science.gov (United States)

    Guillamat-Prats, Raquel; Gay-Jordi, Gemma; Xaubet, Antoni; Peinado, Victor I; Serrano-Mollar, Anna

    2014-07-01

    Alveolar Type II cell transplantation has been proposed as a cell therapy for the treatment of idiopathic pulmonary fibrosis. Its long-term benefits include repair of lung fibrosis, but its success partly depends on the restoration of lung homeostasis. Our aim was to evaluate surfactant protein restoration after alveolar Type II cell transplantation in an experimental model of bleomycin-induced lung fibrosis in rats. Lung fibrosis was induced by intratracheal instillation of bleomycin. Alveolar Type II cells were obtained from healthy animals and transplanted 14 days after bleomycin was administered. Furthermore, one group transplanted with alveolar macrophages and another group treated with surfactant were established to evaluate the specificity of the alveolar Type II cell transplantation. The animals were euthanized at 21 days after bleomycin instillation. Lung fibrosis was confirmed by a histologic study and an evaluation of the hydroxyproline content. Changes in surfactant proteins were evaluated by mRNA expression, Western blot and immunofluorescence studies. The group with alveolar Type II cell transplantation was the only one to show a reduction in the degree of lung fibrosis and a complete recovery to normal levels of surfactant proteins. One of the mechanisms involved in the beneficial effect of alveolar Type II cell transplantation is restoration of lung surfactant protein levels, which is required for proper respiratory function. Copyright © 2014 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  17. A sensitive fluorescent probe for the polar solvation dynamics at protein-surfactant interfaces.

    Science.gov (United States)

    Singh, Priya; Choudhury, Susobhan; Singha, Subhankar; Jun, Yongwoong; Chakraborty, Sandipan; Sengupta, Jhimli; Das, Ranjan; Ahn, Kyo-Han; Pal, Samir Kumar

    2017-05-17

    Relaxation dynamics at the surface of biologically important macromolecules is important taking into account their functionality in molecular recognition. Over the years it has been shown that the solvation dynamics of a fluorescent probe at biomolecular surfaces and interfaces account for the relaxation dynamics of polar residues and associated water molecules. However, the sensitivity of the dynamics depends largely on the localization and exposure of the probe. For noncovalent fluorescent probes, localization at the region of interest in addition to surface exposure is an added challenge compared to the covalently attached probes at the biological interfaces. Here we have used a synthesized donor-acceptor type dipolar fluorophore, 6-acetyl-(2-((4-hydroxycyclohexyl)(methyl)amino)naphthalene) (ACYMAN), for the investigation of the solvation dynamics of a model protein-surfactant interface. A significant structural rearrangement of a model histone protein (H1) upon interaction with anionic surfactant sodium dodecyl sulphate (SDS) as revealed from the circular dichroism (CD) studies is nicely corroborated in the solvation dynamics of the probe at the interface. The polarization gated fluorescence anisotropy of the probe compared to that at the SDS micellar surface clearly reveals the localization of the probe at the protein-surfactant interface. We have also compared the sensitivity of ACYMAN with other solvation probes including coumarin 500 (C500) and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylamino-styryl)-4H-pyran (DCM). In comparison to ACYMAN, both C500 and DCM fail to probe the interfacial solvation dynamics of a model protein-surfactant interface. While C500 is found to be delocalized from the protein-surfactant interface, DCM becomes destabilized upon the formation of the interface (protein-surfactant complex). The timescales obtained from this novel probe have also been compared with other femtosecond resolved studies and molecular dynamics simulations.

  18. A Common Polymorphism in the SFTPD Gene Influences Assembly, Function, and Concentration of Surfactant Protein D

    DEFF Research Database (Denmark)

    Leth-Larsen, Rikke; Garred, Peter; Jensenius, Henriette

    2005-01-01

    Surfactant protein D (SP-D) plays important roles in the host defense against infectious microorganisms and in regulating the innate immune response to a variety of pathogen-associated molecular pattern. SP-D is mainly expressed by type II cells of the lung, but SP-D is generally found on epithel......Surfactant protein D (SP-D) plays important roles in the host defense against infectious microorganisms and in regulating the innate immune response to a variety of pathogen-associated molecular pattern. SP-D is mainly expressed by type II cells of the lung, but SP-D is generally found...

  19. HIV Infection and Circulating Levels of Prosurfactant Protein B and Surfactant Protein D.

    Science.gov (United States)

    Shiels, Meredith S; Kirk, Gregory D; Drummond, M Bradley; Dhillon, Dilsher; Hanash, Samir M; Taguchi, Ayumu; Engels, Eric A

    2018-01-17

    Prosurfactant protein B (pro-SFTPB) and surfactant protein D (SFTPD) are markers of lung inflammation and damage. We estimated geometric mean pro-SFTPB and SFTPD levels in 500 human immunodeficiency virus (HIV)-infected and 300 HIV-uninfected injection drug users, adjusting for smoking and other covariates. Pro-SFTPB levels were significantly higher among people with HIV (PWH) (adjusted geometric mean, 21.4 vs 18.1 ng/mL; P = .03), and were higher with lower CD4 counts (P trend = .001), higher HIV RNA (P trend = .05), and without highly active antiretroviral therapy (P = .03). These associations were not observed for SFTPD. Serum levels of pro-SFTPB are elevated among PWH and are associated with immunosuppression and uncontrolled viremia. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  20. Disaturated-phosphatidylcholine and Surfactant protein-B turnover in human acute lung injury and in control patients

    Directory of Open Access Journals (Sweden)

    Rizzi Sabina

    2011-03-01

    Full Text Available Abstract Background Patients with Adult Respiratory Distress Syndrome (ARDS and Acute Lung Injury (ALI have low concentrations of disaturated-phosphatidylcholine and surfactant protein-B in bronchoalveolar lavage fluid. No information is available on their turnover. Objectives To analyze disaturated-phosphatidylcholine and surfactant protein-B turnover in patients with ARDS/ALI and in human adults with normal lungs (controls. Methods 2H2O as precursor of disaturated-phosphatidylcholine-palmitate and 113C-Leucine as precursor of surfactant protein-B were administered intravenously to 12 patients with ARDS/ALI and to 8 controls. Disaturated-phosphatidylcholine and surfactant protein-B were isolated from serial tracheal aspirates, and their fractional synthetic rate was derived from the 2H and 13C enrichment curves, obtained by gas chromatography mass spectrometry. Disaturated-phosphatidylcholine, surfactant protein-B, and protein concentrations in tracheal aspirates were also measured. Results 1 Surfactant protein-B turned over at faster rate than disaturated-phosphatidylcholine both in ARDS/ALI patients and in controls. 2 In patients with ARDS/ALI the fractional synthesis rate of disaturated-phosphatidylcholine was 3.1 times higher than in controls (p Conclusions 1 Disaturated-phosphatidylcholine and surfactant protein-B have a different turnover both in healthy and diseased lungs. 2 In ARDS/ALI the synthesis of these two surfactant components may be differently regulated.

  1. Coating nanoparticles with tunable surfactants facilitates control over the protein corona.

    Science.gov (United States)

    Müller, J; Bauer, K N; Prozeller, D; Simon, J; Mailänder, V; Wurm, F R; Winzen, S; Landfester, K

    2017-01-01

    Nanoparticles with long blood circulation time are a prerequisite for targeted drug delivery. To make the nanoparticles invisible for phagocytizing cells, functional moieties on the particle surface are believed to be necessary to attract specific so-called 'stealth' proteins forming a protein 'corona'. Currently, covalent attachment of those moieties represents the only way to achieve that attraction. However, that approach requires a high synthetic effort and is difficult to control. Therefore, we present the coating of model nanoparticles with biodegradable polymeric surfactants as an alternative method. The thermodynamic parameters of the coating process can be tuned by adjusting the surfactants' block lengths and hydrophilicity. Consequently, the unspecific protein adsorption and aggregation tendency of the particles can be controlled, and stealth proteins inhibiting cell uptake are enriched on their surface. This non-covalent approach could be applied to any particle type and thus facilitates tuning the protein corona and its biological impact. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. A novel continuous powder aerosolizer (CPA) for inhalative administration of highly concentrated recombinant surfactant protein-C (rSP-C) surfactant to preterm neonates.

    Science.gov (United States)

    Pohlmann, G; Iwatschenko, P; Koch, W; Windt, H; Rast, M; de Abreu, M Gama; Taut, F J H; De Muynck, C

    2013-12-01

    In pulmonary medicine, aerosolization of substances for continuous inhalation is confined to different classes of nebulizers with their inherent limitations. Among the unmet medical needs is the lack of an aerosolized surfactant preparation for inhalation by preterm neonates, to avoid the risks associated with endotracheal intubation and surfactant bolus instillation. In the present report, we describe a high-concentration continuous powder aerosolization system developed for delivery of inhalable surfactant to preterm neonates. The developed device uses a technique that allows efficient aerosolization of dry surfactant powder, generating a surfactant aerosol of high concentration. In a subsequent humidification step, the heated aerosol particles are covered with a surface layer of water. The wet surfactant aerosol is then delivered to the patient interface (e.g., nasal prongs) through a tube. The performance characteristics of the system are given as mass concentration, dose rate, and size distribution of the generated aerosol. Continuous aerosol flows of about 0.84 L/min can be generated from dry recombinant surfactant protein-C surfactant, with concentrations of up to 12 g/m(3) and median particle sizes of the humidified particles in the range of 3 to 3.5 μm at the patient interface. The system has been successfully used in preclinical studies. The device with its continuous high-concentration delivery is promising for noninvasive delivery of surfactant aerosol to neonates and has the potential for becoming a versatile disperser platform closing the gap between continuously operating nebulizers and discontinuously operating dry powder inhaler devices.

  3. No Ameliorating Effect of Surfactant Protein D on DSS-Induced Colitis in Mice

    DEFF Research Database (Denmark)

    Nexøe, Anders Bathum; Pilecki, Bartosz; Husby, Steffen

    Inflammatory bowel diseases (IBD) are disorders associated to a pathological immune response. Surfactant protein D (SP-D) is part of the innate host defense and has known anti-inflammatory effects. We hypothesize that SP-D dampens dextran sodium sulfate (DSS)-induced colitis by reducing innate...

  4. Denaturation of proteins by surfactants studied by the Taylor dispersion analysis.

    Directory of Open Access Journals (Sweden)

    Aldona Jelińska

    Full Text Available We showed that the Taylor Dispersion Analysis (TDA is a fast and easy to use method for the study of denaturation proteins. We applied TDA to study denaturation of β-lactoglobulin, transferrin, and human insulin by anionic surfactant sodium dodecyl sulfate (SDS. A series of measurements at constant protein concentration (for transferrin was 1.9 x 10-5 M, for β- lactoglobulin was 7.6 x 10-5 M, and for insulin was 1.2 x 10-4 M and varying SDS concentrations were carried out in the phosphate-buffered saline (PBS. The structural changes were analyzed based on the diffusion coefficients of the complexes formed at various surfactant concentrations. The concentration of surfactant was varied in the range from 1.2 x 10-4 M to 8.7 x 10-2 M. We determined the minimum concentration of the surfactant necessary to change the native conformation of the proteins. The minimal concentration of SDS for β-lactoglobulin and transferrin was 4.3 x 10-4 M and for insulin 2.3 x 10-4 M. To evaluate the TDA as a novel method for studying denaturation of proteins we also applied other methods i.e. electronic circular dichroism (ECD and dynamic light scattering (DLS to study the same phenomenon. The results obtained using these methods were in agreement with the results from TDA.

  5. Long-term stability and circadian variation in circulating levels of surfactant protein D

    DEFF Research Database (Denmark)

    Hoegh, Silje Vermedal; Sorensen, Grith Lykke; Tornoe, Ida

    2010-01-01

    Surfactant protein D (SP-D) is an oligomeric calcium-dependent lectin with important roles in innate host defence against infectious microorganisms. Several studies have shown that patients with inflammatory lung disease have elevated levels of circulating SP-D, and serum SP-D has been suggested...

  6. Dynamic strength of the interaction between lung surfactant protein D (SP-D) and saccharide ligands

    DEFF Research Database (Denmark)

    Thormann, Esben; Dreyer, Jakob K; Simonsen, Adam C

    2007-01-01

    In order to investigate the dynamic strength of the interaction between lung surfactant protein D (SP-D) and different sugars, maltose, mannose, glucose, and galactose, we have used an atomic force microscope to monitor the interaction on a single molecule scale. The experiment is performed...

  7. Structural characterization of human and bovine surfactant protein D (SP-D)

    DEFF Research Database (Denmark)

    Leth-Larsen, Rikke; Holmskov, U; Højrup, P

    1999-01-01

    Human and bovine surfactant proteins D (SP-D) were purified from late amniotic fluid and bronchioalveolar lavage on the basis of its Ca(2+)-dependent affinity for maltose. The molecular mass of a trimeric subunit was determined by matrix-assisted laser desorption ionization MS to lie in the range...

  8. Surfactant protein A genetic variants associate with severe respiratory insufficiency in pandemic influenza A virus infection

    NARCIS (Netherlands)

    Herrera-Ramos, Estefanía; López-Rodríguez, Marta; Ruíz-Hernández, José Juan; Horcajada, Juan Pablo; Borderías, Luis; Lerma, Elisabeth; Blanquer, José; Pérez-González, María Carmen; García-Laorden, María Isabel; Florido, Yanira; Mas-Bosch, Virginia; Montero, Milagro; Ferrer, José María; Sorlí, Luisa; Vilaplana, Carlos; Rajas, Olga; Briones, Marisa; Aspa, Javier; López-Granados, Eduardo; Solé-Violán, Jordi; de Castro, Felipe Rodríguez; Rodríguez-Gallego, Carlos

    2014-01-01

    Inherited variability in host immune responses influences susceptibility and outcome of Influenza A virus (IAV) infection, but these factors remain largely unknown. Components of the innate immune response may be crucial in the first days of the infection. The collectins surfactant protein (SP)-A1,

  9. The role of surfactant protein D in chemotherapy-induced gastrointestinal toxicity in mice

    DEFF Research Database (Denmark)

    Leicht von Huth, Sebastian; Rathe, Mathias; Sørensen, Grith Lykke

    Surfactant protein D (SP-D) is a host defense molecule produced by epithelial cells. SP-D is known for its role in pulmonary innate immunology, but is present in mucosa throughout the body. SP-D has been shown to be regulated in the gastrointestinal (GI-) mucosa of chemotherapy-treated piglets. H...

  10. Segregated phases in pulmonary surfactant membranes do not show coexistence of lipid populations with differentiated dynamic properties

    DEFF Research Database (Denmark)

    Bernardino de la Serna, Jorge; Orädd, Greger; Bagatolli, Luis

    2009-01-01

    surfactant membranes and membranes reconstituted from two surfactant hydrophobic fractions (i.e., all the lipids plus the hydrophobic proteins SP-B and SP-C, or only the total lipid fraction). These preparations show micrometer-sized fluid ordered/disordered phase coexistence, associated with a broad...... endothermic transition ending close to 37°C. However, both types of membrane exhibit uniform lipid mobility when analyzed by electron paramagnetic resonance with different spin-labeled phospholipids. A similar feature is observed with pulse-field gradient NMR experiments on oriented membranes reconstituted...... from the two types of surfactant hydrophobic extract. These latter results suggest that lipid dynamics are similar in the coexisting fluid phases observed by fluorescence microscopy. Additionally, it is found that surfactant proteins significantly reduce the average intramolecular lipid mobility...

  11. Surfactant Protein-D-Encoding Gene Variant Polymorphisms Are Linked to Respiratory Outcome in Premature Infants

    DEFF Research Database (Denmark)

    Sorensen, Grith Lykke; Dahl, Marianne; Tan, Qihua

    2014-01-01

    OBJECTIVE: Associations between the genetic variation within or downstream of the surfactant protein-D-encoding gene (SFTPD), which encodes the collectin surfactant protein-D (SP-D) and may lead to respiratory distress syndrome or bronchopulmonary dysplasia, recently were reported. Our aim...... were used to associate genetic variation to SP-D, respiratory distress (RD), oxygen requirement, and respiratory support. RESULTS: The 5'-upstream SFTPD SNP rs1923534 and the 3 structural SNPs rs721917, rs2243639, and rs3088308 were associated with the SP-D level. The same SNPs were associated with RD......, a requirement for supplemental oxygen, and a requirement for respiratory support. Haplotype analyses identified 3 haplotypes that included the minor alleles of rs1923534, rs721917, and rs3088308 that exhibited highly significant associations with decreased SP-D levels and decreased ORs for RD, oxygen...

  12. Surfactant protein A genetic variants associate with severe respiratory insufficiency in pandemic influenza A virus infection

    OpenAIRE

    Herrera-Ramos, Estefanía; López-Rodríguez, Marta; Ruíz-Hernández, José Juan; Horcajada, Juan Pablo; Borderías, Luis; Lerma, Elisabeth; Blanquer, José; Pérez-González, María Carmen; García-Laorden, María Isabel; Florido, Yanira; Mas-Bosch, Virginia; Montero, Milagro; Ferrer, José María; Sorlí, Luisa; Vilaplana, Carlos

    2014-01-01

    Introduction Inherited variability in host immune responses influences susceptibility and outcome of Influenza A virus (IAV) infection, but these factors remain largely unknown. Components of the innate immune response may be crucial in the first days of the infection. The collectins surfactant protein (SP)-A1, -A2, and -D and mannose-binding lectin (MBL) neutralize IAV infectivity, although only SP-A2 can establish an efficient neutralization of poorly glycosylated pandemic IAV strains. Meth...

  13. Factors Influencing the Measurement of Plasma/Serum Surfactant Protein D Levels by ELISA

    OpenAIRE

    Bratcher, Preston E.; Gaggar, Amit

    2014-01-01

    BACKGROUND: Extensive variations in human surfactant protein D (SP-D) levels in circulation as measured by ELISA exist in the published literature. In order to determine the source of these variations, factors influencing the measurement by ELISA were explored. MATERIALS AND METHODS: Peripheral blood from healthy individuals was collected into various vacutainers during the same blood draw. Recombinant SP-D was diluted into different matrices and used for a standard curve. Samples were analyz...

  14. Microbiota Composition and Pulmonary Surfactant Protein Expression as Markers of Death by Drowning.

    Science.gov (United States)

    Lee, So-Yeon; Woo, Seung-Kyun; Lee, So-Min; Ha, Eun-Ju; Lim, Kyoung-Hee; Choi, Kyung-Hwa; Roh, Young-Hee; Eom, Yong-Bin

    2017-07-01

    Pathological diagnosis of drowning remains a challenge for forensic science, because of a lack of pathognomonic findings. We analyzed microbiota and surfactant protein in the lungs for a novel diagnosis of drowning. All rats were divided into drowning, postmortem submersion, and control groups. The water, lungs, closed organs (kidney and liver), and cardiac blood in rats were assayed by targeting 16S ribosomal RNA of Miseq sequencing. Lung samples were analyzed by immunohistochemical staining for surfactant protein A. The closed organs and cardiac blood of drowned group have a lot of aquatic microbes, which have not been detected in postmortem submersion group. Furthermore, intra-alveolar granular staining of surfactant protein A (SP-A) was severely observed in the drowned group than the postmortem submersion and control groups. The findings suggested that the presence of aquatic microbiota in the closed organs and increased expression of SP-A could be markers for a diagnosis of drowning. © 2017 American Academy of Forensic Sciences.

  15. Effect of salts and nonionic surfactants on thermal characteristics of egg white proteins.

    Science.gov (United States)

    Nasabi, Mahshad; Labbafi, Mohsen; Mousavi, Mohammad E; Madadlou, Ashkan

    2017-09-01

    Effect of salts (Sodium chloride (NaCl), Sodium sulfate (Na 2 SO 4 ), Ammonium sulfate ((NH 4 ) 2 SO 4 ), and nonionic surfactants (glycerol, tween20, tween80) on thermal properties of egg white proteins as a whole were investigated. Egg white solutions with additive (0, 0.5 and 1%) were collected after 0, 1 and 2min heat treatment. Physico-chemical properties of egg white proteins were evaluated by measuring heat coagulation time, solubility and turbidity of solution. Adding glycerol caused the most significant decrease in turbidity and increase in heat coagulation time and solubility of egg white, although Sodium Chloride had the least positive impact on physico-chemical properties of egg white under heat treatment. The Fourier transform infrared (FT-IR) spectroscopy analysis of heat treated egg white proteins as a whole with additives demonstrated changes in secondary protein structure, which are presented regarding the shape, intensity and position of FT-IR band. Meanwhile, it showed a good correlation with the physico-chemical properties consequences. Generally, the effect of nonionic surfactants were more noticeable than that of salts in preventing of egg white proteins aggregation under heat treatment. By improving thermal stability of egg white proteins, its usage in thermal processing industry can be evolved. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Molecular characterization of the porcine surfactant, pulmonary-associated protein C gene

    DEFF Research Database (Denmark)

    Cirera, S.; Nygård, A.B.; Jensen, H.E.

    2006-01-01

    were found in a newborn pig lung cDNA library: a full-length clone and a clone missing exon 5. cDNA sequence comparison revealed four synonymous and two nonsynonymous substitutions and in-frame insertions at the beginning of exon 5. Comparison of the SFTPC coding region between several mammals showed......The surfactant, pulmonary-associated protein C (SFTPC) is a peptide secreted by the alveolar type II pneumocytes of the lung. We have characterized the porcine SFTPC gene at genomic, transcriptional, and protein levels. The porcine SFTPC is a single-copy gene on pig chromosome 14. Two transcripts...

  17. Activity and biophysical inhibition resistance of a novel synthetic lung surfactant containing Super-Mini-B DATK peptide

    Directory of Open Access Journals (Sweden)

    Robert H. Notter

    2016-01-01

    Full Text Available Background/objectives. This study examines the surface activity, resistance to biophysical inhibition, and pulmonary efficacy of a synthetic lung surfactant containing glycerophospholipids combined with Super Mini-B (S-MB DATK, a novel and stable molecular mimic of lung surfactant protein (SP-B. The objective of the work is to test whether S-MB DATK synthetic surfactant has favorable biophysical and physiological activity for future use in treating surfactant deficiency or dysfunction in lung disease or injury.Methods. The structure of S-MB DATK peptide was analyzed by homology modeling and by FTIR spectroscopy. The in vitro surface activity and inhibition resistance of synthetic S-MB DATK surfactant was assessed in the presence and absence of albumin, lysophosphatidylcholine (lyso-PC, and free fatty acids (palmitoleic and oleic acid. Adsorption and dynamic surface tension lowering were measured with a stirred subphase dish apparatus and a pulsating bubble surfactometer (20 cycles/min, 50% area compression, 37 °C. In vivo pulmonary activity of S-MB DATK surfactant was measured in ventilated rabbits with surfactant deficiency/dysfunction induced by repeated lung lavages that resulted in arterial PO2 values <100 mmHg.Results. S-MB DATK surfactant had very high surface activity in all assessments. The preparation adsorbed rapidly to surface pressures of 46–48 mN/m at 37 °C (low equilibrium surface tensions of 22–24 mN/m, and reduced surface tension to <1 mN/m under dynamic compression on the pulsating bubble surfactometer. S-MB DATK surfactant showed a significant ability to resist inhibition by serum albumin, C16:0 lyso-PC, and free fatty acids, but surfactant inhibition was mitigated by increasing surfactant concentration. S-MB DATK synthetic surfactant quickly improved arterial oxygenation and lung compliance after intratracheal instillation to ventilated rabbits with severe surfactant deficiency.Conclusions. S-MB DATK is an active mimic

  18. Biosurfactants and surfactants interacting with membranes and proteins: Same but different?

    Science.gov (United States)

    Otzen, Daniel E

    2017-04-01

    Biosurfactants (BS) are surface-active molecules produced by microorganisms. For several decades they have attracted interest as promising alternatives to current petroleum-based surfactants. Aside from their green profile, they have remarkably low critical micelle concentrations, reduce the air/water surface tension to very low levels and are excellent emulsifiers, all of which make them comparable or superior to their synthetic counterparts. These remarkable physical properties derive from their more complex chemical structures in which hydrophilic and hydrophobic regions are not as clearly separated as chemical surfactants but have a more mosaic distribution of polarity as well as branched or circular structures. This allows the lipopeptide surfactin to adopt spherical structures to facilitate dense packing at interfaces. They are also more complex. Glycolipid BS, e.g. rhamnolipids (RL) and sophorolipids, are produced biologically as mixtures which vary in the size and saturation of the hydrophobic region as well as modifications in the hydrophilic headgroup, such as the number of sugar groups and different levels of acetylation, leading to variable surface-active properties. Their amphiphilicity allows RL to insert easily into membranes at sub-cmc concentrations to modulate membrane structure and extract lipopolysaccharides, leading to extensive biofilm remodeling in vivo, sometimes in collaboration with hydrophobic RL precursors. Thanks to their mosaicity, even anionic BS like RL only bind weakly to proteins and show much lower denaturing potency, even supporting membrane protein refolding. Nevertheless, they can promote protein degradation by proteases e.g. by neutralizing positive charges, which together with their biofilm-combating properties makes them very promising detergent surfactants. This article is part of a Special Issue entitled: Lipid order/lipid defects and lipid-control of protein activity edited by Dirk Schneider. Copyright © 2016 Elsevier B

  19. Nonlinear Surface Dilatational Rheology and Foaming Behavior of Protein and Protein Fibrillar Aggregates in the Presence of Natural Surfactant.

    Science.gov (United States)

    Wan, Zhili; Yang, Xiaoquan; Sagis, Leonard M C

    2016-04-19

    The surface and foaming properties of native soy glycinin (11S) and its heat-induced fibrillar aggregates, in the presence of natural surfactant steviol glycoside (STE), were investigated and compared at pH 7.0 to determine the impact of protein structure modification on protein-surfactant interfacial interactions. The adsorption at, and nonlinear dilatational rheological behavior of, the air-water interface were studied by combining drop shape analysis tensiometry, ellipsometry, and large-amplitude oscillatory dilatational rheology. Lissajous plots of surface pressure versus deformation were used to analyze the surface rheological response in terms of interfacial microstructure. The heat treatment generates a mixture of long fibrils and unconverted peptides. The presence of small peptides in 11S fibril samples resulted in a faster adsorption kinetics than that of native 11S. The addition of STE affected the adsorption of 11S significantly, whereas no apparent effect on the adsorption of the 11S fibril-peptide system was observed. The rheological response of interfaces stabilized by 11S-STE mixtures also differed significantly from the response for 11S fibril-peptide-STE mixtures. For 11S, the STE reduces the degree of strain hardening in extension and increases strain hardening in compression, suggesting the interfacial structure may change from a surface gel to a mixed phase of protein patches and STE domains. The foams generated from the mixtures displayed comparable foam stability to that of pure 11S. For 11S fibril-peptide mixtures STE only significantly affects the response in extension, where the degree of strain softening is decreased compared to the pure fibril-peptide system. The foam stability of the fibril-peptide system was significantly reduced by STE. These findings indicate that fibrillization of globular proteins could be a potential strategy to modify the complex surface and foaming behaviors of protein-surfactant mixtures.

  20. Respiratory Tract Infections in Diabetic and Non-Diabetic Individuals are Linked with Serum Surfactant Protein-D

    International Nuclear Information System (INIS)

    Jawed, S.; Parveen, N.

    2015-01-01

    Objective: To find out the rate of respiratory tract infections in diabetic and non-diabetic individuals and their relation with surfactant protein D. Methods: The cross-sectional study was conducted at Dow University of Health Sciences, Karachi, from September 2011 to April 2012, and comprised subjects of both genders between ages of 30 and 60 years. The subjects were divided into four groups: diabetic obese, non-diabetic obese, diabetic non-obese, and non-diabetic-non-obese. A structured questionnaire was used to collect information about respiratory tract infections. Serum surfactant protein D levels were analysed using human surfactant protein D enzyme-linked immunosorbent assay kit. Statistical analysis was performed using SPSS 16. Results: Of the 90 subjects, there were 20(22.2 percent) diabetic obese, 30(33.3 percent) non-diabetic obese, 10(11.1 percent) diabetic non-obese, and 30(33.3 percent) non-diabetic-non-obese. The overall mean age was 36.6±103 years. Among the diabetic obese, 15(75 percent) had respiratory tract infections which was higher than the other study groups, and patients having respiratory tract infections had lower surfactant protein D levels than those who did not have infections (p=0.01). Conclusion: Diabetic obese subjects had greater rate of recurrent respiratory tract infections and had lower concentration of serum surfactant protein D compared to subjects without respiratory tract infections. (author)

  1. No Ameliorating Effect of Surfactant Protein D on DSS-Induced Colitis in Mice

    DEFF Research Database (Denmark)

    Nexøe, Anders Bathum; Pilecki, Bartosz; Husby, Steffen

    Inflammatory bowel diseases (IBD) are disorders associated to a pathological immune response. Surfactant protein D (SP-D) is part of the innate host defense and has known anti-inflammatory effects. We hypothesize that SP-D dampens dextran sodium sulfate (DSS)-induced colitis by reducing innate...... inflammatory signaling and facilitation clearance of apoptotic cells. We induced experimental colitis in C57BL/6N Sftpd-/- (KO) and Sftpd+/+ (WT) mice by administration of 1% or 1.5% DSS for 7 days....

  2. Surfactant protein D multimerization and gene polymorphism in COPD and asthma

    DEFF Research Database (Denmark)

    Fakih, Dalia; Akiki, Zeina; Junker, Kirsten

    2018-01-01

    BACKGROUND AND OBJECTIVE: A structural single nucleotide polymorphism rs721917 in the surfactant protein D (SP-D) gene, known as Met11Thr, was reported to influence the circulating levels and degree of multimerization of SP-D and was associated with both COPD and atopy in asthma. Moreover, diseas...... of SP-D takes place to a significant degree in pulmonary disease. Assays that can separate SP-D proteolytic breakdown products or modified forms from naturally occurring SP-D trimers may result in optimal disease markers for pulmonary inflammatory diseases....

  3. Circulating surfactant protein D is associated to mortality in elderly women

    DEFF Research Database (Denmark)

    Johansson, Helle Wulf; Thinggaard, M.; Tan, Q.

    2013-01-01

    BACKGROUND: Surfactant protein D (SP-D) is produced in the lungs and additional mucosal surfaces. Systemic SP-D levels are previously associated to aging-related- and lifestyle-related disorders and predicts mortality in cardiovascular and lung diseases. However, the association between higher...... serum SP-D levels and mortality in the general population is unknown. We hypothesized that increased systemic levels of SP-D may be used as prognostic factor for assessing the mortality in the elderly. METHODS AND RESULTS: SP-D serum levels were measured in 689 elderly subjects and mortality ratios were...

  4. Localization of surfactant protein-D in the rheumatoid synovial membrane

    DEFF Research Database (Denmark)

    Christensen, Anne Friesgaard; Sorensen, Grith Lykke; Junker, Kirsten

    2018-01-01

    Surfactant protein-D (SP-D) is a collectin, which plays an important role in airway protection and inflammation. The molecule has both pro- and anti-inflammatory capacities depending on its molecular size. Its involvement in joint diseases is largely unknown and the aim of this investigation...... and subsequently prepared for immunohistochemistry. In this first, small-scale comparative study on the occurrence of SP-D in the synovial membrane of RA and OA, we report that SP-D was only present in the microvascular endothelium in subsynovial and pannus tissue and that the immunostaining was much stronger than...

  5. A Common Polymorphism in the SFTPD Gene Influences Assembly, Function, and Concentration of Surfactant Protein D

    DEFF Research Database (Denmark)

    Leth-Larsen, Rikke; Garred, Peter; Jensenius, Henriette

    2005-01-01

    Surfactant protein D (SP-D) plays important roles in the host defense against infectious microorganisms and in regulating the innate immune response to a variety of pathogen-associated molecular pattern. SP-D is mainly expressed by type II cells of the lung, but SP-D is generally found on epithel......Surfactant protein D (SP-D) plays important roles in the host defense against infectious microorganisms and in regulating the innate immune response to a variety of pathogen-associated molecular pattern. SP-D is mainly expressed by type II cells of the lung, but SP-D is generally found...... on epithelial surfaces and in serum. Genotyping for three single-nucleotide variations altering amino acids in the mature protein in codon 11 (Met(11)Thr), 160 (Ala(160)Thr), and 270 (Ser(270)Thr) of the SP-D gene was performed and related to the SP-D levels in serum. Individuals with the Thr/Thr(11)-encoding...... genotype had significantly lower SP-D serum levels than individuals with the Met/Met(11) genotype. Gel filtration chromatography revealed two distinct m.w. peaks with SP-D immunoreactivity in serum from Met/Met(11)-encoding genotypes. In contrast, Thr/Thr(11) genotypes lacked the highest m.w. form...

  6. Monocyte CD64 or CD89 targeting by surfactant protein D/anti-Fc receptor mediates bacterial uptake.

    NARCIS (Netherlands)

    Tacken, P.J.; Batenburg, J.J.

    2006-01-01

    We recently showed that a chimeric protein, consisting of a recombinant fragment of human surfactant protein D (rfSP-D) coupled to a Fab' fragment directed against the human Fcalpha receptor (CD89), effectively targets pathogens recognized by SP-D to human neutrophils. The present study evaluates

  7. Polymorphism in SFTPD gene affects assembly and constitutional serum levels of surfactant protein D in a Lebanese population

    DEFF Research Database (Denmark)

    Fakih, Dalia; Chamat, Soulaima; Medlej-Hashim, Myrna

    2014-01-01

    Surfactant protein D (SP-D), an oligomeric lung-derived lectin, has essential roles in innate immunity. It can be measured in serum. Previous studies have shown that constitutional SP-D serum levels and the protein degree of multimerization are genetically influenced. We aimed to establish the di...

  8. The effects of GH and hormone replacement therapy on serum concentrations of mannan-binding lectin, surfactant protein D and vitamin D binding protein in Turner syndrome

    DEFF Research Database (Denmark)

    Gravholt, Claus Højbjerg; Leth-Larsen, Rikke; Lauridsen, Anna Lis

    2004-01-01

    function. In the present study we examined whether GH or hormone replacement therapy (HRT) in Turner syndrome (TS) influence the serum concentrations of MBL and two other proteins partaking in the innate immune defence, surfactant protein D (SP-D) and vitamin D binding protein (DBP). DESIGN: Study 1...

  9. Signal amplification in electrochemical detection of buckwheat allergenic protein using field effect transistor biosensor by introduction of anionic surfactant

    Directory of Open Access Journals (Sweden)

    Sho Hideshima

    2016-03-01

    Full Text Available Food allergens, especially buckwheat proteins, sometimes induce anaphylactic shock in patients after ingestion. Development of a simple and rapid screening method based on a field effect transistor (FET biosensor for food allergens in food facilities or products is in demand. In this study, we achieved the FET detection of a buckwheat allergenic protein (BWp16, which is not charged enough to be electrically detected by FET biosensors, by introducing additional negative charges from anionic surfactants to the target proteins. A change in the FET characteristics reflecting surface potential caused by the adsorption of target charged proteins was observed when the target sample was coupled with the anionic surfactant (sodium dodecyl sulfate; SDS, while no significant response was detected without any surfactant treatment. It was suggested that the surfactant conjugated with the protein could be useful for the charge amplification of the target proteins. The surface plasmon resonance analysis revealed that the SDS-coupled proteins were successfully captured by the receptors immobilized on the sensing surface. Additionally, we obtained the FET responses at various concentrations of BWp16 ranging from 1 ng/mL to 10 μg/mL. These results suggest that a signal amplification method for FET biosensing is useful for allergen detection in the food industry.

  10. Surfactant-bound monolithic columns for separation of proteins in capillary high performance liquid chromatography.

    Science.gov (United States)

    Gu, Congying; He, Jun; Jia, Jinping; Fang, Nenghu; Simmons, Robert; Shamsi, Shahab A

    2010-01-22

    A surfactant-bound monolithic stationary phase based on the co-polymerization of 11-acrylamino-undecanoic acid (AAUA) is designed for capillary high performance liquid chromatography (HPLC). Using D-optimal design, the effect of the polymerization mixture (concentrations of monomer, crosslinker and porogens) on the chromatographic performance (resolution and analysis time) of the AAUA-EDMA monolithic column was evaluated. The polymerization mixture was optimized using three proteins as model test solutes. The D-optimal design indicates a strong dependence of chromatographic parameters on the concentration of porogens (1,4-butanediol and water) in the polymerization mixture. Optimized solutions for fast separation and high resolution separation, respectively, were obtained using the proposed multivariate optimization. Differences less than 6.8% between the predicted and the experimental values in terms of resolution and retention time indeed confirmed that the proposed approach is practical. Using the optimized column, fast separation of proteins could be obtained in 2.5 min, and a tryptic digest of myoglobin was successfully separated on the high resolution column. The physical properties (i.e., morphology, porosity and permeability) of the optimized monolithic column were thoroughly investigated. It appears that this surfactant-bound monolith may have a great potential as a new generation of capillary HPLC stationary phase. Copyright 2009 Elsevier B.V. All rights reserved.

  11. Surfactant-Bound Monolithic Columns for Separation of Proteins in Capillary High Performance Liquid Chromatography

    Science.gov (United States)

    Gu, Congying; He, Jun; Jia, Jinping; Fang, Nenghu; Simmons, Robert; Shamsi, Shahab A.

    2011-01-01

    A surfactant bound monolithic stationary phase based on the co-polymerization of 11-acrylamino-undecanoic acid (AAUA) is designed for capillary high performance liquid chromatography (HPLC). Using D-optimal design, the effect of the polymerization mixture (concentrations of monomer, crosslinker and porogens) on the chromatographic performance (resolution and analysis time) of the AAUA-EDMA monolithic column was evaluated. The polymerization mixture was optimized using three proteins as model test solutes. The D-optimal design indicates a strong dependence of chromatographic parameters on the concentration of porogens (1,4-butanediol and water) in the polymerization mixture. Optimized solutions for fast separation and high resolution separation, respectively, were obtained using the proposed multivariate optimization. Differences less than 6.8% between the predicted and the experimental values in terms of resolution and retention time indeed confirmed that the proposed approach is practical. Using the optimized column, fast separation of proteins could be obtained in 2.5 min, and a tryptic digest of myoglobin was successfully separated on the high resolution column. The physical properties (i.e. morphology, porosity and permeability) of the optimized monolithic column were thoroughly investigated. It appears that this surfactant-bound monolith may have a great potential as a new generation of capillary HPLC stationary phase. PMID:20031139

  12. Surfactant Protein D is a candidate biomarker for subclinical tobacco smoke-induced lung damage

    DEFF Research Database (Denmark)

    Lock Johansson, Sofie; Tan, Qihua; Holst, Rene

    2014-01-01

    Variation in Surfactant Protein D (SP-D) is associated with lung function in tobacco smoke-induced chronic respiratory disease. We hypothesized that the same association exists in the general population and could be used to identify individuals sensitive to smoke-induced lung damage. The associat......Variation in Surfactant Protein D (SP-D) is associated with lung function in tobacco smoke-induced chronic respiratory disease. We hypothesized that the same association exists in the general population and could be used to identify individuals sensitive to smoke-induced lung damage...... or haplotypes, and expiratory lung function were assessed using twin study methodology and mixed-effects models. Significant inverse associations were evident between sSP-D and the forced expiratory volume in 1 second and forced vital capacity in the presence of current tobacco smoking but not in non...... with lung function measures in interaction with tobacco smoking. The obtained data suggest sSP-D as a candidate biomarker in risk assessments for subclinical tobacco smoke-induced lung damage. The data and derived conclusion warrant confirmation in a longitudinal population following chronic obstructive...

  13. Human surfactant protein A2 gene mutations impair dimmer/trimer assembly leading to deficiency in protein sialylation and secretion.

    Directory of Open Access Journals (Sweden)

    Yi Song

    Full Text Available Surfactant protein A2 (SP-A2 plays an essential role in surfactant metabolism and lung host defense. SP-A2 mutations in the carbohydrate recognition domain have been related to familial pulmonary fibrosis and can lead to a recombinant protein secretion deficiency in vitro. In this study, we explored the molecular mechanism of protein secretion deficiency and the subsequent biological effects in CHO-K1 cells expressing both wild-type and several different mutant forms of SP-A2. We demonstrate that the SP-A2 G231V and F198S mutants impair the formation of dimmer/trimer SP-A2 which contributes to the protein secretion defect. A deficiency in sialylation, but not N-linked glycosylation, is critical to the observed dimmer/trimer impairment-induced secretion defect. Furthermore, both mutant forms accumulate in the ER and form NP-40-insoluble aggregates. In addition, the soluble mutant SP-A2 could be partially degraded through the proteasome pathway but not the lysosome or autophagy pathway. Intriguingly, 4-phenylbutyrate acid (4-PBA, a chemical chaperone, alleviates aggregate formation and partially rescued the protein secretion of SP-A2 mutants. In conclusion, SP-A2 G231V and F198S mutants impair the dimmer/trimer assembly, which contributes to the protein sialylation and secretion deficiency. The intracellular protein mutants could be partially degraded through the proteasome pathway and also formed aggregates. The treatment of the cells with 4-PBA resulted in reduced aggregation and rescued the secretion of mutant SP-A2.

  14. Surfactant protein D binds to human immunodeficiency virus (HIV) envelope protein gp120 and inhibits HIV replication

    DEFF Research Database (Denmark)

    Meschi, Joseph; Crouch, Erika C; Skolnik, Paul

    2005-01-01

    The envelope protein (gp120) of human immunodeficiency virus (HIV) contains highly conserved mannosylated oligosaccharides. These glycoconjugates contribute to resistance to antibody neutralization, and binding to cell surface lectins on macrophages and dendritic cells. Mannose-binding lectin (MBL......) binds to gp120 and plays a role in defence against the virus. In this study it is demonstrated that surfactant protein D (SP-D) binds to gp120 and inhibits HIV infectivity at significantly lower concentrations than MBL. The binding of SP-D was mediated by its calcium-dependent carbohydrate...... defence against HIV. A chimeric protein containing the N-terminal and collagen domains of SP-D linked to the neck and carbohydrate-recognition domains of MBL (called SP-D/MBL(neck+CRD)) had greater ability to bind to gp120 and inhibit virus replication than either SP-D or MBL. The enhanced binding of SP...

  15. The elevation of serum napsin A in idiopathic pulmonary fibrosis, compared with KL-6, surfactant protein-A and surfactant protein-D

    Directory of Open Access Journals (Sweden)

    Samukawa Takuya

    2012-09-01

    Full Text Available Abstract Background Napsin A, an aspartic protease, is mainly expressed in alveolar type-II cells and renal proximal tubules and is a putative immunohistochemical marker for pulmonary adenocarcinomas. This study sought to determine whether napsin A could be measured in the serum to evaluate its relationship to idiopathic pulmonary fibrosis (IPF and determine whether renal dysfunction might affect serum napsin A levels. Methods Serum levels of napsin A were measured in 20 patients with IPF, 34 patients with lung primary adenocarcinoma, 12 patients with kidney diseases, and 20 healthy volunteers. Surfactant protein (SP-A, SP-D, and Krebs von den Lungen-6 (KL-6 levels in serum and pulmonary function tests were also evaluated in IPF patients. Results Circulating levels of napsin A were increased in patients with IPF, as compared with healthy controls, and they correlated with the severity of disease. Moreover, the serum napsin A levels were not elevated in patients with pulmonary adenocarcinoma or renal dysfunction. The distinguishing point between IPF and the controls was that the area under the receiver operating characteristic curve (ROC of napsin A was larger than that of KL-6, SP-A, or SP-D. Conclusion These findings suggest that serum napsin A may be a candidate biomarker for IPF.

  16. Small surfactant-like peptides can drive soluble proteins into active aggregates

    Directory of Open Access Journals (Sweden)

    Zhou Bihong

    2012-01-01

    Full Text Available Abstract Background Inactive protein inclusion bodies occur commonly in Escherichia coli (E. coli cells expressing heterologous proteins. Previously several independent groups have found that active protein aggregates or pseudo inclusion bodies can be induced by a fusion partner such as a cellulose binding domain from Clostridium cellulovorans (CBDclos when expressed in E. coli. More recently we further showed that a short amphipathic helical octadecapeptide 18A (EWLKAFYEKVLEKLKELF and a short beta structure peptide ELK16 (LELELKLKLELELKLK have a similar property. Results In this work, we explored a third type of peptides, surfactant-like peptides, for performing such a "pulling-down" function. One or more of three such peptides (L6KD, L6K2, DKL6 were fused to the carboxyl termini of model proteins including Aspergillus fumigatus amadoriase II (AMA, all three peptides were used, Bacillus subtilis lipase A (LipA, only L6KD was used, hereinafter the same, Bacillus pumilus xylosidase (XynB, and green fluorescent protein (GFP, and expressed in E. coli. All fusions were found to predominantly accumulate in the insoluble fractions, with specific activities ranging from 25% to 92% of the native counterparts. Transmission electron microscopic (TEM and confocal fluorescence microscopic analyses confirmed the formation of protein aggregates in the cell. Furthermore, binding assays with amyloid-specific dyes (thioflavin T and Cong red to the AMA-L6KD aggregate and the TEM analysis of the aggregate following digestion with protease K suggested that the AMA-L6KD aggregate may contain structures reminiscent of amyloids, including a fibril-like structure core. Conclusions This study shows that the surfactant-like peptides L6KD and it derivatives can act as a pull-down handler for converting soluble proteins into active aggregates, much like 18A and ELK16. These peptide-mediated protein aggregations might have important implications for protein aggregation in

  17. Chemotherapy modulates intestinal immune gene expression including surfactant Protein-D and deleted in malignant brain tumors 1 in piglets

    DEFF Research Database (Denmark)

    Rathe, Mathias; Thomassen, Mads; Shen, René L.

    2016-01-01

    the BUCY and DOX piglets. Selected genes of potential biological significance with a similar change in expression across the treatments were controlled by real-time polymerase chain reaction. Key innate defense molecules, including surfactant protein-D and deleted in malignant brain tumors 1, were among...

  18. Circulating surfactant protein -D is low and correlates negatively with systemic inflammation in early, untreated rheumatoid arthritis

    DEFF Research Database (Denmark)

    Christensen, Anne Friesgaard; Sørensen, Grith Lykke; Hørslev-Petersen, Kim

    2010-01-01

    Surfactant protein D (SP-D) is a collectin with immuno-regulatory functions, which may depend on oligomerization. Anti-microbial and anti-inflammatory properties have been attributed to multimeric SP-D variants, while trimeric subunits per se have been suggested to enhance inflammation. Previously...

  19. Circulating surfactant protein -D is low and correlates negatively with systemic inflammation in early, untreated rheumatoid arthritis

    DEFF Research Database (Denmark)

    Christensen, Anne Friesgaard; Sørensen, Grith Lykke; Hørslev-Petersen, Kim

    2010-01-01

    ABSTRACT: INTRODUCTION: Surfactant protein D (SP-D) is a collectin with immuno-regulatory functions, which may depend on oligomerization. Anti-microbial and anti-inflammatory properties have been attributed to multimeric SP-D variants, while trimeric subunits per se have been suggested to enhance...

  20. Monoclonal antibody-assisted structure-function analysis of the carbohydrate recognition domain of surfactant protein D

    DEFF Research Database (Denmark)

    Hartshorn, Kevan L; White, Mitchell R; Rynkiewicz, Michael

    2010-01-01

    Surfactant protein D (SP-D) plays important roles in host defense against a variety of pathogens including influenza A virus (IAV). Ligand binding by SP-D is mediated by the trimeric neck and carbohydrate recognition domain (NCRD). We used monoclonal antibodies (mAbs) against human SP-D and a panel...

  1. Innate Defense against Influenza A Virus: Activity of Human Neutrophil Defensins and Interactions of Defensins with Surfactant Protein D

    DEFF Research Database (Denmark)

    Hartshorn, Kevan L.; White, Mitchell R.; Tecle, Tesfaldet

    2006-01-01

    Surfactant protein D (SP-D) plays important roles in innate host defense against influenza A virus (IAV) infection, in part by modifying interactions with neutrophils. Human neutrophil defensins (HNPs) inhibit infectivity of enveloped viruses, including IAV. Our goal in this study...... at sites of active inflammation....

  2. Utilization of dairy byproduct proteins, surfactants, and enzymes in frozen dough.

    Science.gov (United States)

    Asghar, Ali; Anjum, Faqir Muhammad; Allen, Jonathan C

    2011-04-01

    Use of natural additives is gaining popularity among the masses as they are becoming more conscious about their diet and health. Frozen dough products are one of the recent examples of value-added cereal products which face stability problems during extended storage periods of times. Dairy whey proteins, surfactants, and certain enzymes are considered important natural additives which could be used to control the water redistribution problem in the dough structure during the storage condition. They interact with the starch and gluten network in a dough system and thus behave as dough improvers and strengtheners. These natural additives not only help to bind extra moisture but also to improve texture and sensory attributes in frozen dough bakery products. © Taylor and Francis Group, LLC

  3. Surfactant protein D, a clinical biomarker for chronic obstructive pulmonary disease with excellent discriminant values

    DEFF Research Database (Denmark)

    Akiki, Zeina; Fakih, Dalia; Jounblat, Rania

    2016-01-01

    Biological markers can help to better identify a disease or refine its diagnosis. In the present study, the association between surfactant protein D (SP-D) and chronic obstructive pulmonary disease (COPD) was studied among subjects consulting for respiratory diseases or symptoms and was compared...... administered and lung function tests were performed. Biological markers were measured in blood samples according to standardized procedures. The association between SP-D and COPD was investigated using logistic regression models. Receiver-operating characteristic curves were used for threshold identification...... patients were identified (sensitivity, 76.4 and 77.8%; specificity, 89.3 and 88.5%, respectively). The results indicate that SP-D can differentiate COPD from other respiratory symptoms or diseases. Used with socio-demographic characteristics and respiratory symptoms, SP-D is able to discriminate COPD...

  4. Assessment of the antiviral properties of recombinant surfactant protein D against influenza B virus in vitro.

    Science.gov (United States)

    Hillaire, Marine L B; van Eijk, Martin; Vogelzang-van Trierum, Stella E; Nieuwkoop, Nella J; van Riel, Debby; Fouchier, Ron A M; Kuiken, Thijs; Osterhaus, Albert D M E; Haagsman, Henk P; Rimmelzwaan, Guus F

    2015-01-02

    The armamentarium of antiviral drugs against influenza viruses is limited. Furthermore, influenza viruses emerge that are resistant to existing antiviral drugs like the M2 and NA inhibitors. Therefore, there is an urgent need for the development of novel classes of antiviral drugs. Here we investigated the antiviral properties of recombinant porcine surfactant protein D (RpSP-D), an innate defense molecule with lectin properties, against influenza B viruses. We have previously shown that porcine SP-D has more potent neutralizing activity against influenza A viruses than human SP-D. Here we show that RpSP-D neutralizes influenza B viruses efficiently and inhibited the binding of these viruses to epithelial cells of the human trachea. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Time-dependent changes in pulmonary surfactant function and composition in acute respiratory distress syndrome due to pneumonia or aspiration

    Directory of Open Access Journals (Sweden)

    Kuchenbuch Tim

    2007-07-01

    Full Text Available Abstract Background Alterations to pulmonary surfactant composition have been encountered in the Acute Respiratory Distress Syndrome (ARDS. However, only few data are available regarding the time-course and duration of surfactant changes in ARDS patients, although this information may largely influence the optimum design of clinical trials addressing surfactant replacement therapy. We therefore examined the time-course of surfactant changes in 15 patients with direct ARDS (pneumonia, aspiration over the first 8 days after onset of mechanical ventilation. Methods Three consecutive bronchoalveolar lavages (BAL were performed shortly after intubation (T0, and four days (T1 and eight days (T2 after intubation. Fifteen healthy volunteers served as controls. Phospholipid-to-protein ratio in BAL fluids, phospholipid class profiles, phosphatidylcholine (PC molecular species, surfactant proteins (SP-A, -B, -C, -D, and relative content and surface tension properties of large surfactant aggregates (LA were assessed. Results At T0, a severe and highly significant reduction in SP-A, SP-B and SP-C, the LA fraction, PC and phosphatidylglycerol (PG percentages, and dipalmitoylation of PC (DPPC was encountered. Surface activity of the LA fraction was greatly impaired. Over time, significant improvements were encountered especially in view of LA content, DPPC, PG and SP-A, but minimum surface tension of LA was not fully restored (15 mN/m at T2. A highly significant correlation was observed between PaO2/FiO2 and minimum surface tension (r = -0.83; p Conclusion We concluded that a profound impairment of pulmonary surfactant composition and function occurs in the very early stage of the disease and only gradually resolves over time. These observations may explain why former surfactant replacement studies with a short treatment duration failed to improve outcome and may help to establish optimal composition and duration of surfactant administration in future

  6. Local chemistry of the surfactant's head groups determines protein stability in reverse micelles.

    Science.gov (United States)

    Senske, Michael; Xu, Yao; Bäumer, Alexander; Schäfer, Sarah; Wirtz, Hanna; Savolainen, Janne; Weingärtner, Hermann; Havenith, Martina

    2018-03-28

    When comparing protein folding in vitro and in vivo significant differences have been found. This has been attributed to crowding and confinement effects. Using a combination of GHz- and THz-dielectric relaxation spectroscopy and MD simulations, we studied hydration dynamics and reviewed protein stability data inside sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and cetyltrimethylammonium bromide (CTAB) reverse micelles which are model systems for confinement. We find that water inside anionic AOT and cationic CTAB reverse micelles is characterized by a strong dielectric depolarization giving rise to a very low relative permittivity compared to an unconfined solution. Despite differences in the hydration dynamics of the surfactant's head groups, simulations using the two-phase thermodynamics method predict a similar reduction in water entropy for both reverse micelle systems compared to bulk water. When we compare the stability data of proteins in these reverse micelles we find that in contrast to our initial expectation, protein stability correlates rather with the local chemistry of the hydrated head groups than with the excluded volume effect or the low global permittivity.

  7. Developmental regulation of chicken surfactant protein A and its localization in lung

    DEFF Research Database (Denmark)

    Zhang, Weidong; Cuperus, Tryntsje; van Dijk, Albert

    2016-01-01

    in the lung lining fluid covering the parabronchial epithelia. Specific cSP-A producing epithelial cells, resembling mammalian type II cells, were identified in the parabronchi. Gene expression of cSP-A markedly increased from embryonic day 14 onwards until the time of hatch, comparable to the SP-A homologue......Surfactant Protein A (SP-A) is a collagenous C-type lectin (collectin) that plays an important role in the early stage of the host immune response. In chicken, SP-A (cSP-A) is expressed as a 26 kDa glycosylated protein in the lung. Using immunohistochemistry, cSP-A protein was detected mainly...... chicken lung lectin, while mannan binding lectin and collectins CL-L1 and CL-K1 only showed slightly changed expression during development. cSP-A protein could be detected as early as ED 18 in lung tissue using Western blotting, and expression increased steadily until day 28 post-hatch. Our observations...

  8. Surfactant Protein D modulates HIV infection of both T-cells and dendritic cells.

    Directory of Open Access Journals (Sweden)

    Jens Madsen

    Full Text Available Surfactant Protein D (SP-D is an oligomerized C-type lectin molecule with immunomodulatory properties and involvement in lung surfactant homeostasis in the respiratory tract. SP-D binds to the enveloped viruses, influenza A virus and respiratory syncytial virus and inhibits their replication in vitro and in vivo. SP-D has been shown to bind to HIV via the HIV envelope protein gp120 and inhibit infectivity in vitro. Here we show that SP-D binds to different strains of HIV (BaL and IIIB and the binding occurs at both pH 7.4 and 5.0 resembling physiological relevant pH values found in the body and the female urogenital tract, respectively. The binding of SP-D to HIV particles and gp120 was inhibited by the presence of several hexoses with mannose found to be the strongest inhibitor. Competition studies showed that soluble CD4 and CVN did not interfere with the interaction between SP-D and gp120. However, soluble recombinant DC-SIGN was shown to inhibit the binding between SP-D and gp120. SP-D agglutinated HIV and gp120 in a calcium dependent manner. SP-D inhibited the infectivity of HIV strains at both pH values of 7.4 and 5.0 in a concentration dependent manner. The inhibition of the infectivity was abolished by the presence of mannose. SP-D enhanced the binding of HIV to immature monocyte derived dendritic cells (iMDDCs and was also found to enhance HIV capture and transfer to the T-cell like line PM1. These results suggest that SP-D can bind to and inhibit direct infection of T-cells by HIV but also enhance the transfer of infectious HIV particles from DCs to T-cells in vivo.

  9. Pulmonary surfactant and lung transplantation

    NARCIS (Netherlands)

    Erasmus, Michiel Elardus

    1997-01-01

    Pulmonary surfactant lowers the surface tension at the air-water interface inside the alveolus. This is achieved by adsorption of surfactant phospholipids at the air-water interface, a process controlled by surfactant-associated proteins, such as SP-A. In this way, surfactant prevents collapse of

  10. Interaction of the N-terminal segment of pulmonary surfactant protein SP-C with interfacial phospholipid films

    DEFF Research Database (Denmark)

    Plasencia, Inés; Keough, Kevin M W; Perez-Gil, Jesus

    2005-01-01

    Pulmonary surfactant protein SP-C is a 35-residue polypeptide composed of a hydrophobic transmembrane alpha-helix and a polycationic, palmitoylated-cysteine containing N-terminal segment. This segment is likely the only structural motif the protein projects out of the bilayer in which SP-C is ins...... related with the ability of SP-C to facilitate reinsertion of surface active lipid molecules into the lung interface during respiratory compression-expansion cycling. Udgivelsesdato: 2005-Jul-30...

  11. Characterization and Prevention of the Adsorption of Surfactant Protein D to Polypropylene

    Science.gov (United States)

    Bratcher, Preston E.; Gaggar, Amit

    2013-01-01

    Surfactant Protein D (SP-D) is a multifunctional protein present in the lung and in respiratory secretions. In the process of developing new experimental approaches to examine SP-D function, we observed that SP-D adsorbs to polypropylene tubes to a great extent, thereby depleting SP-D from the solution. Although it is well known that proteins adsorb nonspecifically to plastic, this effect is usually diminished by treatments to make the plastic “low-retention” or “low-binding”. However, these treatments actually increased the binding of SP-D to the plastic. In addition, this adsorption affected the results of several assays, including proteolytic cleavage assays. In order to block SP-D from adsorbing to polypropylene and the effects caused by this adsorption, we coated the tubes with bovine serum albumin (BSA), as is commonly performed for ELISAs. This coating greatly diminished the amount of SP-D sticking to the plastic, providing an inexpensive and effective method for preventing adsorption and the artifacts resulting from this adsorption. PMID:24039953

  12. Design-based stereological analysis of the lung parenchymal architecture and alveolar type II cells in surfactant protein A and D double deficient mice

    DEFF Research Database (Denmark)

    Jung, A; Allen, L; Nyengaard, Jens Randel

    2005-01-01

    Alveolar epithelial type II cells synthesize and secrete surfactant. The surfactant-associated proteins A and D (SP-A and SP-D), members of the collectin protein family, participate in pulmonary immune defense, modulation of inflammation, and surfactant metabolism. Both proteins are known to have...... overlapping as well as distinct functions. The present study provides a design-based stereological analysis of adult mice deficient in both SP-A and SP-D (A(-)D(-)) with special emphasis on parameters characterizing alveolar architecture and surfactant-producing type II cells. Compared to wild-type, A......, but the mean volume of a single lamellar body remains constant. These results demonstrate that chronic deficiency of SP-A and SP-D in mice leads to parenchymal remodeling, type II cell hyperplasia and hypertrophy, and disturbed intracellular surfactant metabolism. The design-based stereological approach...

  13. Interindividual variability in the expression of surfactant protein A and B in the human lung during development

    Directory of Open Access Journals (Sweden)

    F. Cau

    2016-09-01

    Full Text Available The surfactant complex, thanks to its multiple actions including decrease of surface- tension and antimicrobial activity, plays a fundamental role in newborn survival, lowering the risk of respiratory distress syndrome. The aim of this work was to determine if the synthesis of two surfactant proteins (SP, SPA and pro-SPB, shows some inter-individual variability during lung development in the intrauterine life. Immunoreactivity for SPA and pro-SPB was investigated in the lungs of  40 subjects, including 15 fetuses, ranging from 14 to 22 weeks of gestation, and 25 neonates, from 24 to 41 weeks. Lung samples were formalin fixed, paraffin-embedded and routinely processed. SPA and pro-SPB were detected utilizing commercial antibodies.  A semi-quantitative grading system (1 to 4 was applied, based on the number of reactive cells and the intensity of immunostaining. Surfactant protein immunostaining was found in  three compartments: bronchi, bronchioles and alveoli, starting from 14 weeks of gestation in the bronchial epithelium and from the 21st week in the alveolar spaces. Differences were found regarding SPA and pro-SPB expression in the vast majority of subjects: in some lungs, SPA was more expressed whereas in others pro-SPB showed an higher degree of immunoreactivity. The expression of both surfactant proteins was not strictly correlated with gestational age. Whereas the highest levels of reactivity were detected in at term neonates, on the other hand one case with grade 3 was detected at 22 weeks and one negative case for both proteins was observed at 31 weeks. Our data clearly show a marked inter-individual variability regarding the production of SPA and pro-SPB and suggest the existence of other epigenetic factors, acting during gestation, that might influence surfactant production and, consequently, the survival potential of  neonates at birth. 

  14. Human salivary agglutinin binds to lung surfactant protein-D and is identical with scavenger receptor protein gp-340

    DEFF Research Database (Denmark)

    Ligtenberg, T J; Bikker, F J; Groenink, J

    2001-01-01

    by quadrupole time-of-flight (Q-TOF) tandem MS. The sequence showed 100% identity with part of the scavenger receptor cysteine-rich ('SRCR') domain found in gp-340/DMBT1 (deleted in malignant brain tumours-1). The mass spectrum revealed 11 peaks with an identical mass as a computer-simulated trypsin digest....../PAGE and the amino acid composition of agglutinin, was found to be nearly identical with that of gp-340. It was shown by Western blotting that monoclonal antibodies against gp-340 reacted with salivary agglutinin, and monoclonals against agglutinin reacted with gp-340. It was demonstrated that gp-340 and agglutinin...... bound in a similar way to Streptococcus mutans and surfactant protein-D. Histochemically, the distribution of gp-340 in the submandibular salivary glands was identical with the agglutinin distribution, as shown in a previous paper [Takano, Bogert, Malamud, Lally and Hand (1991) Anat. Rec. 230, 307...

  15. The origin and evolution of the surfactant system in fish: insights into the evolution of lungs and swim bladders.

    Science.gov (United States)

    Daniels, Christopher B; Orgeig, Sandra; Sullivan, Lucy C; Ling, Nicholas; Bennett, Michael B; Schürch, Samuel; Val, Adalberto Luis; Brauner, Colin J

    2004-01-01

    Several times throughout their radiation fish have evolved either lungs or swim bladders as gas-holding structures. Lungs and swim bladders have different ontogenetic origins and can be used either for buoyancy or as an accessory respiratory organ. Therefore, the presence of air-filled bladders or lungs in different groups of fishes is an example of convergent evolution. We propose that air breathing could not occur without the presence of a surfactant system and suggest that this system may have originated in epithelial cells lining the pharynx. Here we present new data on the surfactant system in swim bladders of three teleost fish (the air-breathing pirarucu Arapaima gigas and tarpon Megalops cyprinoides and the non-air-breathing New Zealand snapper Pagrus auratus). We determined the presence of surfactant using biochemical, biophysical, and morphological analyses and determined homology using immunohistochemical analysis of the surfactant proteins (SPs). We relate the presence and structure of the surfactant system to those previously described in the swim bladders of another teleost, the goldfish, and those of the air-breathing organs of the other members of the Osteichthyes, the more primitive air-breathing Actinopterygii and the Sarcopterygii. Snapper and tarpon swim bladders are lined with squamous and cuboidal epithelial cells, respectively, containing membrane-bound lamellar bodies. Phosphatidylcholine dominates the phospholipid (PL) profile of lavage material from all fish analyzed to date. The presence of the characteristic surfactant lipids in pirarucu and tarpon, lamellar bodies in tarpon and snapper, SP-B in tarpon and pirarucu lavage, and SPs (A, B, and D) in swim bladder tissue of the tarpon provide strong evidence that the surfactant system of teleosts is homologous with that of other fish and of tetrapods. This study is the first demonstration of the presence of SP-D in the air-breathing organs of nonmammalian species and SP-B in actinopterygian

  16. Surfactant protein-D and exposure to bioaerosols in wastewater and garbage workers.

    Science.gov (United States)

    Daneshzadeh Tabrizi, R; Bernard, A; Thommen, A M; De Winter, F; Oppliger, A; Hilfiker, S; Tschopp, A; Hotz, P

    2010-12-01

    Bioaerosols and their constituents, such as endotoxins, are capable of causing an inflammatory reaction at the level of the lung-blood barrier, which becomes more permeable. Thus, it was hypothesized that occupational exposure to bioaerosols can increase leakage of surfactant protein-D (SP-D), a lung-specific protein, into the bloodstream. SP-D was determined by ELISA in 316 wastewater workers, 67 garbage collectors, and 395 control subjects. Exposure was assessed with four interview-based indicators and by preliminary endotoxin measurements using the Limulus amoebocyte lysate assay. Influence of exposure on serum SP-D was assessed by multiple linear regression considering smoking, glomerular function, lung diseases, obesity, and other confounders. Overall, mean exposure levels to endotoxins were below 100 EU/m(3). However, special tasks of wastewater workers caused higher endotoxin exposure. SP-D concentration was slightly increased in this occupational group and associated with the occurrence of splashes and contact to raw sewage. No effect was found in garbage collectors. Smoking increased serum SP-D. No clinically relevant correlation between spirometry results and SP-D concentrations appeared. These results support the hypothesis that inhalation of bioaerosols, even at low concentrations, has a subclinical effect on the lung-blood barrier, the permeability of which increases without associated spirometric changes.

  17. Surfactant protein D delays Fas- and TRAIL-mediated extrinsic pathway of apoptosis in T cells.

    Science.gov (United States)

    Djiadeu, Pascal; Kotra, Lakshmi P; Sweezey, Neil; Palaniyar, Nades

    2017-05-01

    Only a few extracellular soluble proteins are known to modulate apoptosis. We considered that surfactant-associated protein D (SP-D), an innate immune collectin present on many mucosal surfaces, could regulate apoptosis. Although SP-D is known to be important for immune cell homeostasis, whether SP-D affects apoptosis is unknown. In this study we aimed to determine the effects of SP-D on Jurkat T cells and human T cells dying by apoptosis. Here we show that SP-D binds to Jurkat T cells and delays the progression of Fas (CD95)-Fas ligand and TRAIL-TRAIL receptor induced, but not TNF-TNF receptor-mediated apoptosis. SP-D exerts its effects by reducing the activation of initiator caspase-8 and executioner caspase-3. SP-D also delays the surface exposure of phosphatidylserine. The effect of SP-D was ablated by the presence of caspase-8 inhibitor, but not by intrinsic pathway inhibitors. The binding ability of SP-D to dying cells decreases during the early stages of apoptosis, suggesting the release of apoptotic cell surface targets during apoptosis. SP-D also delays FasL-induced death of primary human T cells. SP-D delaying the progression of the extrinsic pathway of apoptosis could have important implications in regulating immune cell homeostasis at mucosal surfaces.

  18. Surfactant Protein A Recognizes Outer Membrane Protein OprH on Pseudomonas aeruginosa Isolates From Individuals With Chronic Infection.

    Science.gov (United States)

    Qadi, Mohammad; Lopez-Causapé, Carla; Izquierdo-Rabassa, Sofia; Mateu Borrás, Margalida; Goldberg, Joanna B; Oliver, Antonio; Albertí, Sebastián

    2016-11-01

    Surfactant protein A (SP-A) plays a critical role in the clearance of Pseudomonas aeruginosa from the lung. However, there is limited information about the interaction of this protein with P. aeruginosa isolates from individuals with cystic fibrosis (CF). We characterized the interplay between SP-A and a collection of isogenic sequential isolates from 7 patients with CF. We identified outer membrane protein OprH as a novel ligand for SP-A on P. aeruginosa The last-available (late) isolates from patients with CF bound significantly less SP-A than their respective first-available (early) isolates. This difference could be associated with a reduction in the expression of OprH. Binding of SP-A to OprH promoted phagocytic killing; thus, late CF isolates were at least 2-fold more resistant to SP-A-mediated killing by human macrophages than their respective early isolates. We postulate that the reduction of OprH expression is a previously unrecognized adaptation of P. aeruginosa to the lung of individuals with CF that facilitates the escape of the microorganism from SP-A-mediated phagocytic killing. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  19. Stable intermediates determine proteins' primary unfolding sites in the presence of surfactants

    DEFF Research Database (Denmark)

    Petersen, Steen Vang; Andersen, Kell kleiner; Enghild, Jan J.

    2009-01-01

    ) and cationic (DTAC) surfactant concentrations corresponding to specific conformational transitions, using the surfactant-robust broad-specificity proteases Savinase and Alcalase. Cleavage sites are identified by SDS-PAGE and N-terminal sequencing. We observe well-defined cleavage fragments, which suggest...

  20. Front-face fluorescence spectroscopy study of globular proteins in emulsions: displacement of BSA by a nonionic surfactant.

    Science.gov (United States)

    Rampon, V; Genot, C; Riaublanc, A; Anton, M; Axelos, M A V; McClements, D J

    2003-04-23

    The displacement of a globular protein (bovine serum albumin, BSA) from the surface of oil droplets in concentrated oil-in-water emulsions by a nonionic surfactant (polyoxyethylene sorbitan monolauarate, Tween 20) was studied using front-face fluorescence spectroscopy (FFFS). This method relies on measurement of the change in intensity (I(MAX)) and wavelength (lambda(MAX)) of the maximum in the tryptophan emission spectrum. A series of oil-in-water emulsions (21 wt % n-hexadecane, 0.22 wt % BSA, pH 7.0) containing different molar ratios of Tween 20 to BSA (R = 0-131) were prepared. As the surfactant concentration was increased, the protein was progressively displaced from the droplet surfaces. At R > or = 66, the protein was completely displaced from the droplet surfaces. There was an increase in both I(MAX) and lambda(MAX) with increasing Tween 20 concentration up to R = 66, which correlated with the increase in the ratio of nonadsorbed to adsorbed protein. In contrast, there was a decrease in I(MAX) and lambda(MAX) with Tween 20 concentration in protein solutions and for R > or = 66 in the emulsions, which was attributed to binding of the surfactant to the protein. This study shows that FFFS is a powerful technique for nondestructively providing information about the interfacial composition of droplets in concentrated protein-stabilized emulsions in situ. Nevertheless, in general the suitability of the technique may also depend on protein type and the nature of the physicochemical matrix surrounding the proteins.

  1. Innate Defense against Influenza A Virus: Activity of Human Neutrophil Defensins and Interactions of Defensins with Surfactant Protein D

    DEFF Research Database (Denmark)

    Hartshorn, Kevan L.; White, Mitchell R.; Tecle, Tesfaldet

    2006-01-01

    Surfactant protein D (SP-D) plays important roles in innate host defense against influenza A virus (IAV) infection, in part by modifying interactions with neutrophils. Human neutrophil defensins (HNPs) inhibit infectivity of enveloped viruses, including IAV. Our goal in this study was to characte......Surfactant protein D (SP-D) plays important roles in innate host defense against influenza A virus (IAV) infection, in part by modifying interactions with neutrophils. Human neutrophil defensins (HNPs) inhibit infectivity of enveloped viruses, including IAV. Our goal in this study...... fluid and reduced the antiviral activity of bronchoalveolar lavage fluid. HNP-1 and -2 differed somewhat in their independent antiviral activity and their binding to SP-D. These results are relevant to the early phase of host defense against IAV, and suggest a complex interplay between SP-D and HNPs...

  2. The flagellum of Pseudomonas aeruginosa is required for resistance to clearance by surfactant protein A.

    Directory of Open Access Journals (Sweden)

    Shiping Zhang

    2007-06-01

    Full Text Available Surfactant protein A (SP-A is an important lung innate immune protein that kills microbial pathogens by opsonization and membrane permeabilization. We investigated the basis of SP-A-mediated pulmonary clearance of Pseudomonas aeruginosa using genetically-engineered SP-A mice and a library of signature-tagged P. aeruginosa mutants. A mutant with an insertion into flgE, the gene that encodes flagellar hook protein, was preferentially cleared by the SP-A(+/+ mice, but survived in the SP-A(-/- mice. Opsonization by SP-A did not play a role in flgE clearance. However, exposure to SP-A directly permeabilized and killed the flgE mutant, but not the wild-type parental strain. P. aeruginosa strains with mutation in other flagellar genes, as well as mucoid, nonmotile isolates from cystic fibrosis patients, were also permeabilized by SP-A. Provision of the wild-type fliC gene restored the resistance to SP-A-mediated membrane permeabilization in the fliC-deficient bacteria. In addition, non-mucoid, motile revertants of CF isolates reacquired resistance to SP-A-mediated membrane permeability. Resistance to SP-A was dependent on the presence of an intact flagellar structure, and independent of flagellar-dependent motility. We provide evidence that flagellar-deficient mutants harbor inadequate amounts of LPS required to resist membrane permeabilization by SP-A and cellular lysis by detergent targeting bacterial outer membranes. Thus, the flagellum of P. aeruginosa plays an indirect but important role resisting SP-A-mediated clearance and membrane permeabilization.

  3. Human surfactant protein D: SP-D contains a C-type lectin carbohydrate recognition domain.

    Science.gov (United States)

    Rust, K; Grosso, L; Zhang, V; Chang, D; Persson, A; Longmore, W; Cai, G Z; Crouch, E

    1991-10-01

    Lung surfactant protein D (SP-D) shows calcium-dependent binding to specific saccharides, and is similar in domain structure to certain members of the calcium-dependent (C-type) lectin family. Using a degenerate oligomeric probe corresponding to a conserved peptide sequence derived from the amino-terminus of the putative carbohydrate binding domain of rat and bovine SP-D, we screened a human lung cDNA library and isolated a 1.4-kb cDNA for the human protein. The relationship of the cDNA to SP-D was established by several techniques including amino-terminal microsequencing of SP-D-derived peptides, and immunoprecipitation of translation products of transcribed mRNA with monospecific antibodies to SP-D. In addition, antibodies to a synthetic peptide derived from a predicted unique epitope within the carbohydrate recognition domain of SP-D specifically reacted with SP-D. DNA sequencing demonstrated a noncollagenous carboxy-terminal domain that is highly homologous with the carboxy-terminal globular domain of previously described C-type lectins. This domain contains all of the so-called "invariant residues," including four conserved cysteine residues, and shows high homology with the mannose-binding subfamily of C-type lectins. Sequencing also demonstrated an amino-terminal collagenous domain that contains an uninterrupted sequence of 59 Gly-X-Y triplets and that also contains the only identified consensus for asparagine-linked oligosaccharides. The studies demonstrate that SP-D is a member of the C-type lectin family, and confirm predicted structural similarities to conglutinin, SP-D, and the serum mannose binding proteins.

  4. Surfactant Protein-A inhibits Aspergillus fumigatus-induced allergic T-cell responses

    Directory of Open Access Journals (Sweden)

    Russo Scott J

    2005-08-01

    Full Text Available Abstract Background The pulmonary surfactant protein (SP-A has potent immunomodulatory activities but its role and regulation during allergic airway inflammation is unknown. Methods We studied changes in SP-A expression in the bronchoalveolar lavage (BAL using a murine model of single Aspergillus fumigatus (Af challenge of sensitized animals. Results SP-A protein levels in the BAL fluid showed a rapid, transient decline that reached the lowest values (25% of controls 12 h after intranasal Af provocation of sensitized mice. Decrease of SP-A was associated with influx of inflammatory cells and increase of IL-4 and IL-5 mRNA and protein levels. Since levels of SP-A showed a significant negative correlation with these BAL cytokines (but not with IFN-γ, we hypothesized that SP-A exerts an inhibitory effect on Th2-type immune responses. To study this hypothesis, we used an in vitro Af-rechallenge model. Af-induced lymphocyte proliferation of cells isolated from sensitized mice was inhibited in a dose-dependent manner by addition of purified human SP-A (0.1–10 μg/ml. Flow cytometric studies on Af-stimulated lymphocytes indicated that the numbers of CD4+ (but not CD8+ T cells were significantly increased in the parental population and decreased in the third and fourth generation in the presence of SP-A. Further, addition of SP-A to the tissue culture inhibited Af-induced IL-4 and IL-5 production suggesting that SP-A directly suppressed allergen-stimulated CD4+ T cell function. Conclusion We speculate that a transient lack of this lung collectin following allergen exposure of the airways may significantly contribute to the development of a T-cell dependent allergic immune response.

  5. Association of surfactant protein A polymorphisms with otitis media in infants at risk for asthma

    Directory of Open Access Journals (Sweden)

    Bracken Michael B

    2006-08-01

    Full Text Available Abstract Background Otitis media is one of the most common infections of early childhood. Surfactant protein A functions as part of the innate immune response, which plays an important role in preventing infections early in life. This prospective study utilized a candidate gene approach to evaluate the association between polymorphisms in loci encoding SP-A and risk of otitis media during the first year of life among a cohort of infants at risk for developing asthma. Methods Between September 1996 and December 1998, women were invited to participate if they had at least one other child with physician-diagnosed asthma. Each mother was given a standardized questionnaire within 4 months of her infant's birth. Infant respiratory symptoms were collected during quarterly telephone interviews at 6, 9 and 12 months of age. Genotyping was done on 355 infants for whom whole blood and complete otitis media data were available. Results Polymorphisms at codons 19, 62, and 133 in SP-A1, and 223 in SP-A2 were associated with race/ethnicity. In logistic regression models incorporating estimates of uncertainty in haplotype assignment, the 6A4/1A5haplotype was protective for otitis media among white infants in our study population (OR 0.23; 95% CI 0.07,0.73. Conclusion These results indicate that polymorphisms within SP-A loci may be associated with otitis media in white infants. Larger confirmatory studies in all ethnic groups are warranted.

  6. Surfactant protein a in cystic fibrosis: supratrimeric structure and pulmonary outcome.

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    Matthias Griese

    Full Text Available BACKGROUND: The state of oligomerization of surfactant associated protein-A (SP-A monomers differs between individuals. This likely affects SP-A's functional properties and could thereby influence clinical status in patients with lung diseases. In this study we focus on SP-A structure in cystic fibrosis (CF compared to both healthy subjects and disease controls. METHODS: SP-A composition and function were assessed in both bronchoalveolar lavage (BAL fluid and serum of 46 CF patients with mild disease, 25 patients with chronic bronchitis and 22 healthy subjects by gel chromatography and a functional agglutination assay. Relation of SP-A agglutination ability to disease severity of the subjects was explored. RESULTS: SP-A was present in seven major oligomeric forms with the majority of SP-A being structurally organized as complex oligomeric forms. More complex oligomeric forms were associated with better SP-A function with regard to its agglutination ability. These forms were more frequently observed in BAL than in serum, but there were no differences between disease groups. In CF patients, more complex forms of SP-A were associated with better lung function. CONCLUSIONS: Organizational structure of SP-A affects its functional activity and is linked to disease severity in CF.

  7. Surfactant Protein-B 121ins2 Heterozygosity, Reduced Pulmonary Function and COPD in Smokers

    DEFF Research Database (Denmark)

    Bækvad-Hansen, Marie; Dahl, Morten; Tybjærg-Hansen, Anne

    2010-01-01

    2 mutation have reduced lung function and increased risk for chronic obstructive pulmonary disease (COPD) among smokers. METHODS: We genotyped 47,600 individuals from the adult Danish general population and recorded smoking habits, spirometry and hospital admissions due to COPD. The study.......2-4.8) for spirometry defined COPD and of 2.2(1.0-5.1) for hospitalization due to COPD. Among never smokers, 121ins2 heterozygotes did not differ from wildtypes in lung function or risk of COPD. CONCLUSIONS: Surfactant protein-B 121ins2 heterozygosity is associated with reduced lung function and increased risk for COPD...... that the effect of genotype differ by smoking status. Among smokers, 121ins2 heterozygotes had 9% reduced FEV1%predicted(p=0.0008), 6% reduced FVC%predicted(p=0.01) and 6% reduced FEV1/FVC(p=0.00007), compared with wildtypes. Also among smokers, 121ins2 heterozygotes had odds ratios of 2.4(95%CI 1...

  8. Association of surfactant protein B gene with chronic obstructive pulmonary disease susceptibility.

    Science.gov (United States)

    Yang, J; Wang, B; Zhou, H-X; Liang, B-M; Chen, H; Ma, C-L; Xiao, J; Deng, J; Yan, L; Chen, Y-P; Chen, C-L; Chen, F; Ou, X-M; Feng, Y-L

    2014-11-01

    Genetic predisposition, in addition to smoking, is known to play a key role in susceptibility to chronic obstructive pulmonary disease (COPD). Several candidate genes have been proposed for COPD, including surfactant protein B (SFTPB). However, large studies in populations with different ethnic backgrounds and environments are required to clarify the role of SFTPB in COPD. We investigated the association of SFTPB polymorphisms with COPD susceptibility and lung function in a Chinese Han population. Four single nucleotide polymorphisms (SNPs) in the SFTPB gene were genotyped in 680 COPD patients and 687 controls. Allele frequencies and genotype distributions were compared between cases and controls and the potential relationships between these SNPs and lung function were investigated. Associations between haplotypes and COPD susceptibility were also assessed. The SFTPB exon polymorphism rs1130866 significantly protected subjects from COPD (adjusted P = 0.004) and was associated with an increase in forced expiratory volume in 1 s (FEV(1)) (adjusted P = 0.014). SFTPB variants are associated with COPD susceptibility and lung function in the Chinese Han population.

  9. Comprehensive characterisation of pulmonary and serum surfactant protein D in COPD

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    Erpenbeck Veit J

    2011-03-01

    Full Text Available Abstract Background Pulmonary surfactant protein D (SP-D is considered as a candidate biomarker for the functional integrity of the lung and for disease progression, which can be detected in serum. The origin of SP-D in serum and how serum concentrations are related to pulmonary concentrations under inflammatory conditions is still unclear. Methods In a cross-sectional study comprising non-smokers (n = 10, young - (n = 10, elderly smokers (n = 20, and smokers with COPD (n = 20 we simultaneously analysed pulmonary and serum SP-D levels with regard to pulmonary function, exercise, repeatability and its quaternary structure by native gel electrophoresis. Statistical comparisons were conducted by ANOVA and post-hoc testing for multiple comparisons; repeatability was assessed by Bland-Altman analysis. Results In COPD, median (IQR pulmonary SP-D levels were lower (129(68 ng/ml compared to smokers (young: 299(190, elderly: 296(158 ng/ml; p Conclusions Pulmonary and serum SP-D levels are stable markers influenced by smoking and related to airflow obstruction and disease state. Smaller subunits of pulmonary SP-D and the rapid increase of serum SP-D levels in COPD due to exercise support the translocation hypothesis and its use as a COPD biomarker. Trial registration no interventional trial

  10. Surfactant Protein-D Is Essential for Immunity to Helminth Infection.

    Science.gov (United States)

    Thawer, Sumaiyya; Auret, Jennifer; Schnoeller, Corinna; Chetty, Alisha; Smith, Katherine; Darby, Matthew; Roberts, Luke; Mackay, Rosie-Marie; Whitwell, Harry J; Timms, John F; Madsen, Jens; Selkirk, Murray E; Brombacher, Frank; Clark, Howard William; Horsnell, William G C

    2016-02-01

    Pulmonary epithelial cell responses can enhance type 2 immunity and contribute to control of nematode infections. An important epithelial product is the collectin Surfactant Protein D (SP-D). We found that SP-D concentrations increased in the lung following Nippostrongylus brasiliensis infection; this increase was dependent on key components of the type 2 immune response. We carried out loss and gain of function studies of SP-D to establish if SP-D was required for optimal immunity to the parasite. N. brasiliensis infection of SP-D-/- mice resulted in profound impairment of host innate immunity and ability to resolve infection. Raising pulmonary SP-D levels prior to infection enhanced parasite expulsion and type 2 immune responses, including increased numbers of IL-13 producing type 2 innate lymphoid cells (ILC2), elevated expression of markers of alternative activation by alveolar macrophages (alvM) and increased production of the type 2 cytokines IL-4 and IL-13. Adoptive transfer of alvM from SP-D-treated parasite infected mice into naïve recipients enhanced immunity to N. brasiliensis. Protection was associated with selective binding by the SP-D carbohydrate recognition domain (CRD) to L4 parasites to enhance their killing by alvM. These findings are the first demonstration that the collectin SP-D is an essential component of host innate immunity to helminths.

  11. Exploring the affinity binding of alkylmaltoside surfactants to bovine serum albumin and their effect on the protein stability: A spectroscopic approach.

    Science.gov (United States)

    Hierrezuelo, J M; Carnero Ruiz, C

    2015-08-01

    Steady-state and time-resolved fluorescence together with circular dichroism (CD) spectroscopic studies was performed to examine the interactions between bovine serum albumin (BSA) and two alkylmaltoside surfactants, i.e. n-decyl-β-D-maltoside (β-C10G2) and n-dodecyl-β-D-maltoside (β-C12G2), having identical structures but different tail lengths. Changes in the intrinsic fluorescence of BSA from static as well as dynamic measurements revealed a weak protein-surfactant interaction and gave the corresponding binding curves, suggesting that the binding mechanism of surfactants to protein is essentially cooperative in nature. The behavior of both surfactants is similar, so that the differences detected were attributed to the more hydrophobic nature of β-C12G2, which favors the adsorption of micelle-like aggregates onto the protein surface. These observations were substantially demonstrated by data derived from synchronous, three-dimensional and anisotropy fluorescence experiments. Changes in the secondary structure of the protein induced by the interaction with surfactants were analyzed by CD to determine the contents of α-helix and β-strand. It was noted that whereas the addition of β-C10G2 appears to stabilize the secondary structure of the protein, β-C12G2 causes a marginal denaturation of BSA for a protein:surfactant molar ratio as high as 1 to 100. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Alcohol--Induced Polyelectrolyte-Surfactant Complex Coacervate Systems: Characterization and Applications in Enzyme and Protein Extraction

    Science.gov (United States)

    Nejati Moshtaghin, Mahboubeh

    The focus of this thesis is to achieve a better understanding of the newly discovered surfactant-polyelectrolyte complex coacervate (SPCC) systems induced by fluoroalcohol/acid as well as short chain aliphatic alcohol; and to elucidate their applications in extraction and enrichment of proteins and enzyme. We have discovered that fluoroalcohols and --acids induce complex coacervation and phase separation in the aqueous mixtures of oppositely charged anionic polyelectrolytes; specifically, sodium salts of polyacrylic acid and polymethacrylic acid and cationic surfactant (cetyltrimethylammonium bromide, CTAB) over a broad range of concentrations of mole fractions of the oppositely charged amphiphiles. Accordingly, these new classes of coacervators will significantly broaden the scope and facilitate engineering of new coacervate phases. Toward these goals, we have inspected the formation of surfactant-polyelectrolyte complex coacervates in the presence of fluoroalcohols namely hexafluoroisopropanol (HFIP) and Trifluoroethanol (TFE). Furthermore, the extent of coacervation as a function of concentrations the system components, and charge ratios of the oppositely charged amphiphiles has been investigated. Polyelectrolytes are considered to be milder reagents, as compared to surfactants, regarding proteins denaturation. This highlights the importance of a detailed investigation of the efficiency of our coacervate systems for extraction and preconcentration of proteins and enzymes, especially, when the biological activity of the extracted proteins needs to be maintained based on the objectives mentioned above, the results of the investigations have been organized in four chapters. In Chapter II, the phase behavior of the FA-SPCC will be investigated. The objective is to examine the phase behavior and phase properties with respect to the extent of coacervation in different solution conditions. In particular, the effects of different solution variables such as concentration

  13. Cis-acting sequences from a human surfactant protein gene confer pulmonary-specific gene expression in transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Korfhagen, T.R.; Glasser, S.W.; Wert, S.E.; Bruno, M.D.; Daugherty, C.C.; McNeish, J.D.; Stock, J.L.; Potter, S.S.; Whitsett, J.A. (Cincinnati College of Medicine, OH (USA))

    1990-08-01

    Pulmonary surfactant is produced in late gestation by developing type II epithelial cells lining the alveolar epithelium of the lung. Lack of surfactant at birth is associated with respiratory distress syndrome in premature infants. Surfactant protein C (SP-C) is a highly hydrophobic peptide isolated from pulmonary tissue that enhances the biophysical activity of surfactant phospholipids. Like surfactant phospholipid, SP-C is produced by epithelial cells in the distal respiratory epithelium, and its expression increases during the latter part of gestation. A chimeric gene containing 3.6 kilobases of the promoter and 5{prime}-flanking sequences of the human SP-C gene was used to express diphtheria toxin A. The SP-C-diphtheria toxin A fusion gene was injected into fertilized mouse eggs to produce transgenic mice. Affected mice developed respiratory failure in the immediate postnatal period. Morphologic analysis of lungs from affected pups showed variable but severe cellular injury confined to pulmonary tissues. Ultrastructural changes consistent with cell death and injury were prominent in the distal respiratory epithelium. Proximal components of the tracheobronchial tree were not severely affected. Transgenic animals were of normal size at birth, and structural abnormalities were not detected in nonpulmonary tissues. Lung-specific diphtheria toxin A expression controlled by the human SP-C gene injured type II epithelial cells and caused extensive necrosis of the distal respiratory epithelium. The absence of type I epithelial cells in the most severely affected transgenic animals supports the concept that developing type II cells serve as precursors to type I epithelial cells.

  14. S-nitrosylation of surfactant protein-D controls inflammatory function.

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    Chang-Jiang Guo

    2008-11-01

    Full Text Available The pulmonary collectins, surfactant proteins A and D (SP-A and SP-D have been implicated in the regulation of the innate immune system within the lung. In particular, SP-D appears to have both pro- and anti-inflammatory signaling functions. At present, the molecular mechanisms involved in switching between these functions remain unclear. SP-D differs in its quaternary structure from SP-A and the other members of the collectin family, such as C1q, in that it forms large multimers held together by the N-terminal domain, rather than aligning the triple helix domains in the traditional "bunch of flowers" arrangement. There are two cysteine residues within the hydrophobic N terminus of SP-D that are critical for multimer assembly and have been proposed to be involved in stabilizing disulfide bonds. Here we show that these cysteines exist within the reduced state in dodecameric SP-D and form a specific target for S-nitrosylation both in vitro and by endogenous, pulmonary derived nitric oxide (NO within a rodent acute lung injury model. S-nitrosylation is becoming increasingly recognized as an important post-translational modification with signaling consequences. The formation of S-nitrosothiol (SNO-SP-D both in vivo and in vitro results in a disruption of SP-D multimers such that trimers become evident. SNO-SP-D but not SP-D, either dodecameric or trimeric, is chemoattractive for macrophages and induces p38 MAPK phosphorylation. The signaling capacity of SNO-SP-D appears to be mediated by binding to calreticulin/CD91. We propose that NO controls the dichotomous nature of this pulmonary collectin and that posttranslational modification by S-nitrosylation causes quaternary structural alterations in SP-D, causing it to switch its inflammatory signaling role. This represents new insight into both the regulation of protein function by S-nitrosylation and NO's role in innate immunity.

  15. Ageing and smoking contribute to plasma surfactant proteins and protease imbalance with correlations to airway obstruction

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    Ishikawa Nobuhisa

    2011-04-01

    Full Text Available Abstract Background A significant number of young people start smoking at an age of 13-15, which means that serious smoking-evoked changes may have been occurred by their twenties. Surfactant proteins (SP and matrix metalloproteinases (MMPs and their tissue inhibitors (TIMPs have been linked to cigarette smoke induced lung remodelling and chronic obstructive pulmonary disease (COPD. However, the level of these proteins has not been examined during ageing or in young individuals with short smoking histories. Methods Plasma levels of SP-A, SP-D, MMP-9, and TIMP-1 were measured by EIA/ELISA from young (18-23 years non-smoking controls (YNS (n = 36, smokers (YS (n = 51, middle aged/elderly (37-77 years non-smoking controls (ONS (n = 40, smokers (OS (n = 64 (FEV1/FVC >0.7 in all subjects and patients with COPD (n = 44, 35-79 years. Results Plasma levels of SP-A increased with age and in the older group in relation to smoking and COPD. Plasma SP-D and MMP-9 levels did not change with age but were elevated in OS and COPD as compared to ONS. The TIMP-1 level declined with age but increased in chronic smokers when compared to ONS. The clearest correlations could be detected between plasma SP-A vs. age, pack years and FEV1/FVC. The receiver operating characteristic (ROC curve analysis revealed SP-A to be the best marker for discriminating between patients with COPD and the controls (area under ROC curve of 0.842; 95% confidence interval, 0.785-0.899; p Conclusions Age has a significant contribution to potential markers related to smoking and COPD; SP-A seems to be the best factor in differentiating COPD from the controls.

  16. Differential modulation of the chaperone-like activity of HSP-1/2, a major protein of horse seminal plasma by anionic and cationic surfactants.

    Science.gov (United States)

    Kumar, C Sudheer; Swamy, Musti J

    2017-03-01

    The major protein of equine seminal plasma, HSP-1/2 exhibits chaperone-like activity (CLA) by protecting various target proteins against thermal, chemical and oxidative stress. Polydispersity and surface hydrophobicity of HSP-1/2 were found to be important for its CLA. Surfactants are known to alter certain properties of proteins, e.g. hydrophobicity, charge and conformation either by altering properties of the medium or by direct binding. In the current study, thermal aggregation of alcohol dehydrogenase (ADH) and enolase has been studied in the presence of HSP-1/2, different surfactants and their combinations. The results obtained show that anionic surfactants (SDS, sodium dodecyl benzene sulfate) and neutral surfactants (tween-20, triton X-100) increase the CLA of HSP-1/2 and also inhibit aggregation of the target proteins independently. On the other hand, cationic surfactants (CTAB, alanine palmityl ester) increased the thermal aggregation of ADH and enolase and also decreased the CLA of HSP-1/2. These results are of significant interest as they show that surfactants such as SDS and tween-20 can potentially be used as anti-aggregation agents to prevent thermal aggregation of target proteins. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Weak and saturable protein-surfactant interactions in the denaturation of apo-alpha-lactalbumin by acidic and lactonic sophorolipid

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    Kell K Andersen

    2016-11-01

    Full Text Available 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-alpha-lactalbumin 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 than the acidic form (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 nonionic or zwitterionic surfactants. Inclusion of 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 industry.

  18. Pseudomonas aeruginosa elastase provides an escape from phagocytosis by degrading the pulmonary surfactant protein-A.

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    Zhizhou Kuang

    Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen that causes both acute pneumonitis in immunocompromised patients and chronic lung infections in individuals with cystic fibrosis and other bronchiectasis. Over 75% of clinical isolates of P. aeruginosa secrete elastase B (LasB, an elastolytic metalloproteinase that is encoded by the lasB gene. Previously, in vitro studies have demonstrated that LasB degrades a number of components in both the innate and adaptive immune systems. These include surfactant proteins, antibacterial peptides, cytokines, chemokines and immunoglobulins. However, the contribution of LasB to lung infection by P. aeruginosa and to inactivation of pulmonary innate immunity in vivo needs more clarification. In this study, we examined the mechanisms underlying enhanced clearance of the ΔlasB mutant in mouse lungs. The ΔlasB mutant was attenuated in virulence when compared to the wild-type strain PAO1 during lung infection in SP-A+/+ mice. However, the ΔlasB mutant was as virulent as PAO1 in the lungs of SP-A⁻/⁻ mice. Detailed analysis showed that the ΔlasB mutant was more susceptible to SP-A-mediated opsonization but not membrane permeabilization. In vitro and in vivo phagocytosis experiments revealed that SP-A augmented the phagocytosis of ΔlasB mutant bacteria more efficiently than the isogenic wild-type PAO1. The ΔlasB mutant was found to have a severely reduced ability to degrade SP-A, consequently making it unable to evade opsonization by the collectin during phagocytosis. These results suggest that P. aeruginosa LasB protects against SP-A-mediated opsonization by degrading the collectin.

  19. Phospholipid Composition in Synthetic Surfactants Is Important for Tidal Volumes and Alveolar Stability in Surfactant-Treated Preterm Newborn Rabbits.

    Science.gov (United States)

    Calkovska, Andrea; Linderholm, Bim; Haegerstrand-Björkman, Marie; Pioselli, Barbara; Pelizzi, Nicola; Johansson, Jan; Curstedt, Tore

    2016-01-01

    The development of synthetic surfactants for the treatment of lung pulmonary diseases has been going on for many years. To investigate the effects of phospholipid mixtures combined with SP-B and SP-C analogues on lung functions in an animal model of respiratory distress syndrome. Natural and synthetic phospholipid mixtures with/without SP-B and/or SP-C analogues were instilled in ventilated premature newborn rabbits. Lung functions were evaluated. Treatment with Curosurf or phospholipids from Curosurf combined with SP-B and SP-C analogues gave similar results. Treatment with phospholipids from adult rabbit lungs or liver combined with dipalmitoylphosphatidylcholine (DPPC) and palmitoyloleoylphosphatidylglycerol (POPG) gave tidal volumes (VT) well above physiological levels, but alveolar stability at end-expiration was only achieved when these phospholipids were combined with analogues of SP-B and SP-C. Treatment with egg yolk-PC mixed with DPPC with and without POPG gave small VT, but after addition of both analogues VT was only somewhat lower and lung gas volumes (LGV) similar to those obtained with Curosurf. Substitution of egg yolk-PC (≥99% PC) with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine, and combining them with DPPC, POPG and 2% each of the SP-B and SP-C analogue gave a completely synthetic surfactant with similar effects on VT and LGV as Curosurf. Phospholipid composition is important for VT while the SP-B and SP-C analogues increase alveolar stability at end-expiration. Synthetic surfactant consisting of unsaturated and saturated phosphatidylcholines, POPG and the analogues of SP-B and SP-C has similar activity as Curosurf regarding VT and LGV in an animal model using preterm newborn rabbits ventilated without positive end-expiratory pressure. © 2016 S. Karger AG, Basel.

  20. Surfactant protein-A suppresses eosinophil-mediated killing of Mycoplasma pneumoniae in allergic lungs.

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    Julie G Ledford

    Full Text Available Surfactant protein-A (SP-A has well-established functions in reducing bacterial and viral infections but its role in chronic lung diseases such as asthma is unclear. Mycoplasma pneumoniae (Mp frequently colonizes the airways of chronic asthmatics and is thought to contribute to exacerbations of asthma. Our lab has previously reported that during Mp infection of non-allergic airways, SP-A aides in maintaining airway homeostasis by inhibiting an overzealous TNF-alpha mediated response and, in allergic mice, SP-A regulates eosinophilic infiltration and inflammation of the airway. In the current study, we used an in vivo model with wild type (WT and SP-A(-/- allergic mice challenged with the model antigen ovalbumin (Ova that were concurrently infected with Mp (Ova+Mp to test the hypothesis that SP-A ameliorates Mp-induced stimulation of eosinophils. Thus, SP-A could protect allergic airways from injury due to release of eosinophil inflammatory products. SP-A deficient mice exhibit significant increases in inflammatory cells, mucus production and lung damage during concurrent allergic airway disease and infection (Ova+Mp as compared to the WT mice of the same treatment group. In contrast, SP-A deficient mice have significantly decreased Mp burden compared to WT mice. The eosinophil specific factor, eosinophil peroxidase (EPO, which has been implicated in pathogen killing and also in epithelial dysfunction due to oxidative damage of resident lung proteins, is enhanced in samples from allergic/infected SP-A(-/- mice as compared to WT mice. In vitro experiments using purified eosinophils and human SP-A suggest that SP-A limits the release of EPO from Mp-stimulated eosinophils thereby reducing their killing capacity. These findings are the first to demonstrate that although SP-A interferes with eosinophil-mediated biologic clearance of Mp by mediating the interaction of Mp with eosinophils, SP-A simultaneously benefits the airway by limiting inflammation

  1. Engineering Halomonas spp. as A Low-Cost Production Host for Production of Bio-surfactant Protein PhaP.

    Science.gov (United States)

    Lan, Lu-Hong; Zhao, Han; Chen, Jin-Chun; Chen, Guo-Qiang

    2016-12-01

    Halomonas spp. have been studied as a low cost production host for producing bulk materials such as polyhydroxyalkanoates (PHA) bioplastics, since they are able to grow at high pH and high NaCl concentration under unsterile and continuous conditions without microbial contamination. In this paper, Halomonas strain TD is used as a host to produce a protein named PHA phasin or PhaP which has a potential to be developed into a bio-surfactant. Four Halomonas TD expression strains are constructed based on a strong T7-family expression system. Of these, the strain with phaC deletion and chromosomal expression system resulted in the highest production of PhaP in soluble form, reaching 19% of total cellular soluble proteins and with a yield of 1.86 g/L in an open fed-batch fermentation process. A simple "heat lysis and salt precipitation" method is applied to allow rapid PhaP purification from a mixture of cellular proteins with a PhaP recovery rate of 63%. It clearly demonstrated that Halomonas TD could be used for high yield expression of a bio-surfactant protein PhaP for industrial application in an economical way. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Surfactant protein C peptides with salt-bridges (“ion-locks” promote high surfactant activities by mimicking the α-helix and membrane topography of the native protein

    Directory of Open Access Journals (Sweden)

    Frans J. Walther

    2014-07-01

    Full Text Available Background. Surfactant protein C (SP-C; 35 residues in lungs has a cationic N-terminal domain with two cysteines covalently linked to palmitoyls and a C-terminal region enriched in Val, Leu and Ile. Native SP-C shows high surface activity, due to SP-C inserting in the bilayer with its cationic N-terminus binding to the polar headgroup and its hydrophobic C-terminus embedded as a tilted, transmembrane α-helix. The palmitoylcysteines in SP-C act as ‘helical adjuvants’ to maintain activity by overriding the β-sheet propensities of the native sequences.Objective. We studied SP-C peptides lacking palmitoyls, but containing glutamate and lysine at 4-residue intervals, to assess whether SP-C peptides with salt-bridges (“ion-locks” promote surface activity by mimicking the α-helix and membrane topography of native SP-C.Methods. SP-C mimics were synthesized that reproduce native sequences, but without palmitoyls (i.e., SP-Css or SP-Cff, with serines or phenylalanines replacing the two cysteines. Ion-lock SP-C molecules were prepared by incorporating single or double Glu−–Lys+ into the parent SP-C’s. The secondary structures of SP-C mimics were studied with Fourier transform infrared (FTIR spectroscopy and PASTA, an algorithm that predicts β-sheet propensities based on the energies of the various β-sheet pairings. The membrane topography of SP-C mimics was investigated with orientated and hydrogen/deuterium (H/D exchange FTIR, and also Membrane Protein Explorer (MPEx hydropathy analysis. In vitro surface activity was determined using adsorption surface pressure isotherms and captive bubble surfactometry, and in vivo surface activity from lung function measures in a rabbit model of surfactant deficiency.Results. PASTA calculations predicted that the SP-Css and SP-Cff peptides should each form parallel β-sheet aggregates, with FTIR spectroscopy confirming high parallel β-sheet with ‘amyloid-like’ properties. The enhanced

  3. Effect of perfluorohexane on the expression of cellular adhesion molecules and surfactant protein A in human mesothelial cells in vitro.

    Science.gov (United States)

    Haufe, Dirk; Dahmen, Klaus G; Tiebel, Oliver; Hübler, Matthias; Koch, Thea

    2011-08-01

    The intraperitoneal instillation of perfluorocarbons augmented systemic oxygenation and was protective in mesenteric ischemia-reperfusion and experimental lung injury. To study biocompatibility and potential anti-inflammatory effects of intraperitoneal perfluorocarbons, we evaluated the influence of perfluorohexane and/or inflammatory stimuli on human mesothelial cells in vitro. Perfluorohexane exposure neither impaired cell viability nor induced cellular activation. TNFα enhanced ICAM-1 expression, which was not attenuated by simultaneous perfluorohexane treatment. Concentration of intracellular surfactant protein A tended to be higher in perfluorohexane treated cells compared to controls. Our in vitro data add further evidence that intraperitoneal perfluorocarbon application is feasible without adverse local effects.

  4. Smoking and polymorphisms of genes encoding mannose-binding lectin and surfactant protein-D in patients with rheumatoid arthritis

    DEFF Research Database (Denmark)

    Kristiansen, Malthe; Frisch, Morten; Madsen, Hans Ole

    2014-01-01

    To investigate whether polymorphisms in genes coding for mannose-binding lectin (MBL) and surfactant protein-D (SP-D) are associated directly or by interaction with smoking with rheumatoid arthritis (RA), anti-citrullinated peptide antibody (ACPA) positive RA, and erosive RA. MBL2 genotypes, SFTPD...... smokers. Odds ratios with 95% confidence interval (OR, 95% CI) were calculated using multiple logistic regression analyses controlling for shared epitope. The low-producing SFTPD genotype was not associated with risk of RA or ACPA positive RA, but with erosive disease in the RA patients (OR = 1.8; 95% CI...

  5. Similarities in Self-Assembly of Proteins and Surfactants: an Attempt to Bridge the Gap

    NARCIS (Netherlands)

    Linden, van der E.; Venema, P.

    2007-01-01

    The area of surfactant self assembly has already received attention for more than half a century. Considerable progress has been made in regards to connecting the molecular properties to the assembly morphology and the phase behaviour, where a multitude of different (rather exotic) types of

  6. Magnetic surfactants

    OpenAIRE

    Brown, P.; Alan Hatton, T.; Eastoe, J.

    2015-01-01

    Surfactants are ubiquitous, being important commodity chemicals with wide industrial applications, and essential components of living organisms. With stimuli-responsive surfactants, self-assembly and physicochemical properties of a wide variety of materials may be readily manipulated, both reversibly and irreversibly. Until recently, magnetically responsive surfactants had not been reported. This review reports the recent progress in magnetoresponsive surfactants, covering control of interfac...

  7. Normalisation of surfactant protein -A and -B expression in the lungs of low birth weight lambs by 21 days old.

    Directory of Open Access Journals (Sweden)

    Jia Yin Soo

    Full Text Available Intrauterine growth restriction (IUGR induced by placental restriction (PR in the sheep negatively impacts lung and pulmonary surfactant development during fetal life. Using a sheep model of low birth weight (LBW, we found that there was an increase in mRNA expression of surfactant protein (SP-A, -B and -C in the lung of LBW lambs but no difference in the protein expression of SP-A or -B. LBW also resulted in increased lysosome-associated membrane glycoprotein (LAMP-3 mRNA expression, which may indicate an increase in either the density of type II Alveolar epithelial cells (AEC or maturity of type II AECs. Although there was an increase in glucocorticoid receptor (GR and 11β-hydroxysteroid dehydrogenase (11βHSD-1 mRNA expression in the lung of LBW lambs, we found no change in the protein expression of these factors, suggesting that the increase in SP mRNA expression is not mediated by increased GC signalling in the lung. The increase in SP mRNA expression may, in part, be mediated by persistent alterations in hypoxia signalling as there was an increase in lung HIF-2α mRNA expression in the LBW lamb. The changes in the hypoxia signalling pathway that persist within the lung after birth may be involved in maintaining SP production in the LBW lamb.

  8. Correlation of neonatal pulmonary surfactant protein A gene polymorphism with pneumonia susceptibility and inflammatory response

    Directory of Open Access Journals (Sweden)

    Yi He

    2017-06-01

    Full Text Available Objective: To study the correlation of neonatal pulmonary surfactant protein A gene polymorphism with pneumonia susceptibility and inflammatory response. Methods: Neonates who were born and diagnosed with pneumonia in Zigong Maternity and Child Healthcare Hospital between September 2015 and February 2017 were selected as pneumonia group, and neonates without infection were selected as control group. SP-A gene rs1059054 and rs1136454 loci polymorphism, the contents of inflammatory cytokines in serum as well as the expression of inflammatory transcription factors in peripheral blood were determined. Results: The constituent ratio of rs1059054 loci CC genotype of pneumonia group was significantly higher than that of control group while the constituent ratio of CT and TT genotypes were significantly lower than those of control group; the constituent ratio of rs1136454 loci AA genotype was significantly lower than that of control group while the constituent ratio of AG and GG genotypes were significantly higher than those of control group. PCT, sTREM1, TNF-α and IL-6 levels in serum as well as RORγt mRNA expression in peripheral blood of pneumonia children with SP-A gene rs1059054 loci CC genotype were significantly higher than those of pneumonia children with CT genotype and TT genotype while SOCS1 and Foxp3 mRNA expression in peripheral blood were significantly lower than those of pneumonia children with CT genotype and TT genotype; PCT, sTREM1, TNF-α and IL-6 levels in serum as well as RORγt mRNA expression in peripheral blood of pneumonia children with SP-A gene rs1136454 loci AA genotype were significantly lower than those of pneumonia children with AG genotype and GG genotype while SOCS1 and Foxp3 mRNA expression in peripheral blood were significantly higher than those of pneumonia children with AG genotype and GG genotype. Conclusion: Neonatal SP-A gene rs1059054 loci CC genotype can increase the pneumonia susceptibility and aggravate

  9. A novel nanobody specific for respiratory surfactant protein A has potential for lung targeting

    Directory of Open Access Journals (Sweden)

    Wang SM

    2015-04-01

    Full Text Available Shan-Mei Wang,1,* Xian He,2,* Nan Li,1,* Feng Yu,3 Yang Hu,1 Liu-Sheng Wang,1 Peng Zhang,4 Yu-Kui Du,1 Shan-Shan Du,1 Zhao-Fang Yin,1 Ya-Ru Wei,1 Xavier Mulet,5 Greg Coia,6 Dong Weng,1 Jian-Hua He,3 Min Wu,7 Hui-Ping Li1 1Department of Respiratory Medicine, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, 2School of Medicine, Suzhou University, SuZhou, 3Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 4Department of Chest Surgery, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, People’s Republic of China; 5CSIRO (Commonwealth Scientific and Industrial Research Materials Science and Engineering, Clayton, 6CSIRO Materials Science and Engineering, Parkville, Melbourne, VIC, Australia; 7Department of Basic Sciences, University of North Dakota, Grand Forks, ND, USA *These authors contributed equally to this work Abstract: Lung-targeting drugs are thought to be potential therapies of refractory lung diseases by maximizing local drug concentrations in the lung to avoid systemic circulation. However, a major limitation in developing lung-targeted drugs is the acquirement of lung-specific ligands. Pulmonary surfactant protein A (SPA is predominantly synthesized by type II alveolar epithelial cells, and may serve as a potential lung-targeting ligand. Here, we generated recombinant rat pulmonary SPA (rSPA as an antigen and immunized an alpaca to produce two nanobodies (the smallest naturally occurring antibodies specific for rSPA, designated Nb6 and Nb17. To assess these nanobodies’ potential for lung targeting, we evaluated their specificity to lung tissue and toxicity in mice. Using immunohistochemistry, we demonstrated that these anti-rSPA nanobodies selectively bound to rat lungs with high affinity. Furthermore, we intravenously injected fluorescein isothiocyanate-Nb17 in nude mice and observed its preferential accumulation in the lung to other tissues, suggesting high

  10. Surfactant-free purification of membrane protein complexes from bacteria: application to the staphylococcal penicillin-binding protein complex PBP2/PBP2a

    International Nuclear Information System (INIS)

    Paulin, Sarah; Rosado, Helena; Taylor, Peter W; Jamshad, Mohammed; Dafforn, Timothy R; Garcia-Lara, Jorge; Foster, Simon J; Galley, Nicola F; Roper, David I

    2014-01-01

    Surfactant-mediated removal of proteins from biomembranes invariably results in partial or complete loss of function and disassembly of multi-protein complexes. We determined the capacity of styrene-co-maleic acid (SMA) co-polymer to remove components of the cell division machinery from the membrane of drug-resistant staphylococcal cells. SMA-lipid nanoparticles solubilized FtsZ-PBP2-PBP2a complexes from intact cells, demonstrating the close physical proximity of these proteins within the lipid bilayer. Exposure of bacteria to (-)-epicatechin gallate, a polyphenolic agent that abolishes β-lactam resistance in staphylococci, disrupted the association between PBP2 and PBP2a. Thus, SMA purification provides a means to remove native integral membrane protein assemblages with minimal physical disruption and shows promise as a tool for the interrogation of molecular aspects of bacterial membrane protein structure and function. (paper)

  11. Alterations in nanoparticle protein corona by biological surfactants: impact of bile salts on β-lactoglobulin-coated gold nanoparticles.

    Science.gov (United States)

    Winuprasith, Thunnalin; Chantarak, Sirinya; Suphantharika, Manop; He, Lili; McClements, David Julian

    2014-07-15

    The impact of biological surfactants (bile salts) on the protein (β-lactoglobulin) corona surrounding gold nanoparticles (200 nm) was studied using a variety of analytical techniques at pH 7: dynamic light scattering (DLS); particle electrophoresis (ζ-potential); UV-visible (UV) spectroscopy; transmission electron microscopy (TEM); and surface-enhanced Raman scattering (SERS). The bile salts adsorbed to the protein-coated nanoparticle surfaces and altered their interfacial composition, charge, and structure. SERS spectra of protein-coated nanoparticles after bile salt addition contained bands from both protein and bile salts, indicating that the protein was not fully displaced by the bile salts. UV, DLS and TEM techniques also indicated that the protein coating was not fully displaced from the nanoparticle surfaces. The impact of bile salts could be described by an orogenic mechanism: mixed interfaces were formed that consisted of islands of aggregated proteins surrounded by a sea of bile salts. This knowledge is useful for understanding the interactions of bile salts with protein-coated colloidal particles, which may be important for controlling the fate of colloidal delivery systems in the human gastrointestinal tract, or the gastrointestinal fate of ingested inorganic nanoparticles. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Characterization of cells resistant to the potent histone deacetylase inhibitor spiruchostatin B (SP-B) and effect of overexpressed p21waf1/cip1 on the SP-B resistance or susceptibility of human leukemia cells.

    Science.gov (United States)

    Kanno, Syu-Ichi; Maeda, Naoyuki; Tomizawa, Ayako; Yomogida, Shin; Katoh, Tadashi; Ishikawa, Masaaki

    2012-09-01

    We previously showed that the B cell leukemia cell line NALM-6 had the highest susceptibility among a number of leukemia cell lines to spiruchostatin B (SP-B), a potent histone deacetylase (HDAC) inhibitor. We also showed that SP-B-induced cytotoxicity depended on induction of apoptosis that was mediated by p21waf1/cip1 expression. In the present study, we generated and characterized a stable, SP-B-resistant NALM-6 cell line (NALM-6/SP-B) by continuous exposure to SP-B, starting with a low SP-B concentration. NALM-6/SP-B cells were also more resistant to FK228, which has a similar chemical structure to SP-B, and were slightly more resistant to the P-gp substrates doxorubicin and vincristine than parental cells, but displayed similar susceptibility to other HDAC inhibitors and to paclitaxel as the parental cells. There was little change in the basal mRNA expression of HDAC1, p53, Bax, Bcl-2, Fas, caspase-3, c-Myc and MDR1 in NALM-6/SP-B compared to parental cells, but the mRNA expression of p21waf1/cip1 was decreased. The introduction of an exogenous p21waf1/cip1 expression vector restored SP-B induction of NALM-6/SP-B cell apoptosis. Moreover, overexpressed p21waf1/cip1 enhanced SP-B induction of the apoptosis of the human erythroleukemia leukemia cell line K562 which is less susceptible to SP-B than NALM-6 cells. These results suggest that downregulation of p21waf1/cip1, which is a characteristic feature of NALM-6/SP-B cells, was important for their resistance to SP-B, and that this SP-B resistance could be overcome by the introduction of exogenous p21waf1/cip1. Furthermore, introduction of p21waf1/cip1 to other leukemia cells such as K562 may enhance their susceptibility to SP-B. This is the first report of the characterization of SP-B-resistant cells and of the effect of overexpressed p21waf1/cip1 on the resistance or susceptibility of human leukemia cells to SP-B.

  13. Diseases of Pulmonary Surfactant Homeostasis

    Science.gov (United States)

    Whitsett, Jeffrey A.; Wert, Susan E.; Weaver, Timothy E.

    2015-01-01

    Advances in physiology and biochemistry have provided fundamental insights into the role of pulmonary surfactant in the pathogenesis and treatment of preterm infants with respiratory distress syndrome. Identification of the surfactant proteins, lipid transporters, and transcriptional networks regulating their expression has provided the tools and insights needed to discern the molecular and cellular processes regulating the production and function of pulmonary surfactant prior to and after birth. Mutations in genes regulating surfactant homeostasis have been associated with severe lung disease in neonates and older infants. Biophysical and transgenic mouse models have provided insight into the mechanisms underlying surfactant protein and alveolar homeostasis. These studies have provided the framework for understanding the structure and function of pulmonary surfactant, which has informed understanding of the pathogenesis of diverse pulmonary disorders previously considered idiopathic. This review considers the pulmonary surfactant system and the genetic causes of acute and chronic lung disease caused by disruption of alveolar homeostasis. PMID:25621661

  14. Intrinsic structural differences in the N-terminal segment of pulmonary surfactant protein SP-C from different species

    DEFF Research Database (Denmark)

    Plasencia, I; Rivas, L; Casals, C

    2001-01-01

    Predictive studies suggest that the known sequences of the N-terminal segment of surfactant protein SP-C from animal species have an intrinsic tendency to form beta-turns, but there are important differences on the probable location of these motifs in different SP-C species. Our hypothesis...... is that intrinsic structural determinants of the sequence of the N-terminal region of SP-C could define conformation, acylation and perhaps surface properties of the mature protein. To test this hypothesis we have synthesized peptides corresponding to the 13-residue N-terminal sequence of porcine and canine SP......-C, and studied their structural behaviour in solution and in phospholipid bilayers and monolayers. In these peptides, leucine at position 1 of both sequences has been replaced by tryptophan in order to allow their study by fluorescence spectroscopy. Far-u.v. circular dichroism spectra of the peptides in aqueous...

  15. Effects of the conjugation of whey proteins with gellan polysaccharides on surfactant-induced competitive displacement from the air-water interface.

    Science.gov (United States)

    Cai, B; Ikeda, S

    2016-08-01

    Whey proteins can be used to stabilize foams and emulsions against coalescence because of their ability to form viscoelastic films at the interface that resist film rupture on collision between colloidal particles. However, whey proteins are competitively displaced from the interface if small-molecule surfactants are added, leading to destabilization of the entire system. This is because surfactants are more effective in molecular packing at the interface, and they lower interfacial tension to a greater degree than whey proteins do, but their interfacial films are poor in viscoelasticity. We hypothesized that whey proteins would become more resistant to surfactant-induced competitive displacement if they were conjugated with network-forming polysaccharides. The protein moiety of the conjugate would be expected to enable its adsorption to the interface, and the polysaccharide moiety would be expected to form self-assembled networks, strengthening the interfacial film as a whole. In this study, whey proteins were conjugated with gellan polysaccharides using the Maillard reaction. Atomic force microscopy images of interfacial films formed by the whey protein-gellan conjugate at the air-water interface and transferred onto mica sheets using the Langmuir-Blodgett method revealed that gellan did form self-assembled networks at the interface and that interfacial films also contained a large number of unconjugated whey protein molecules. Following the addition of a small-molecule surfactant (Tween 20) to the sub-phase, surface pressure increased, indicating spontaneous adsorption of surfactants to the interface. Atomic force microscopy images showed decreases in interfacial area coverage by whey proteins as surface pressure increased. At a given surface pressure, the interfacial area coverage by whey protein-gellan conjugates was greater than coverage by unconjugated whey proteins, confirming that whey proteins became more resistant to surfactant-induced displacement after

  16. Microfibril-associated Protein 4 Binds to Surfactant Protein A (SP-A) and Colocalizes with SP-A in the Extracellular Matrix of the Lung

    DEFF Research Database (Denmark)

    Schlosser, Anders; Thomsen, Theresa H.; Shipley, J. Michael

    2006-01-01

    Pulmonary surfactant protein A (SP-A) is an oligomeric collectin that recognizes lipid and carbohydrate moieties present on broad range of micro-organisms, and mediates microbial lysis and clearance. SP-A also modulates multiple immune-related functions including cytokine production and chemotaxis......-A composed of the neck region and carbohydrate recognition domain of SP-A indicating that the interaction between MFAP4 and SP-A is mediated via the collagen domain of SP-A. Monoclonal antibodies directed against MFAP4 and SP-A were used for immunohistochemical analysis, which demonstrates that the two...

  17. Surfactant protein D of the innate immune defence is inversely associated with human obesity and SP-D deficiency infers increased body weight in mice

    DEFF Research Database (Denmark)

    Sorensen, G.L.; Hjelmborg, J.V.B.; Leth-Larsen, R.

    2006-01-01

    Surfactant protein D (SP-D) is a key regulator of pathogen-induced inflammation. SP-D is further involved in lipid homeostasis in mouse lung and circulation and recent data have demonstrated that the body mass index (BMI; in kg/m(2)) is influenced by genes in common with SP-D. The objective...

  18. Surfactant protein D (SP-D) deficiency is attenuated in humanised mice expressing the Met(11)Thr short nucleotide polymorphism of SP-D

    DEFF Research Database (Denmark)

    Knudsen, Lars; Ochs, Katharina; Boxler, Laura

    2013-01-01

    Surfactant protein D (SP-D) is part of the innate immune system involved in lung homeostasis. SP-D knockout mice show accumulations of foamy alveolar macrophages, alveolar lipoproteinosis and pulmonary emphysema. Three single nucleotide polymorphisms (SNPs) have been described in the coding...

  19. An enzyme-linked immunosorbent assay (ELISA) for quantification of mouse surfactant protein D (SP-D)

    DEFF Research Database (Denmark)

    Hansen, Søren; Schmidt, Vivi; Steffensen, Maria Abildgaard

    2008-01-01

    innate immune cells, such as macrophages and neutrophils. It also modulates the adaptive immune response by interacting with antigen-presenting cells and T cells. Monoclonal anti-mouse-SP-D antibodies were raised from SP-D deficient mice using recombinant SP-D as antigen. Ten monoclonal antibodies were......Surfactant protein D (SP-D) is a pattern recognition molecule of the collectin family of C-type lectins. It is found in the airways and at mucosal surfaces. SP-D is part of the innate immune system where it neutralizes and leads to elimination of microorganisms. It regulates the functions of other...... characterized and validated for use in sandwich enzyme-linked immunosorbent assay (ELISA). Based on two of these, we established an ELISA that allows for measurements of mouse SP-D in various body fluids. The final ELISA was optimized and calibrated with a standard of purified recombinant mouse SP-D, which...

  20. Surfactant protein d deficiency in mice is associated with hyperphagia, altered fat deposition, insulin resistance, and increased Basal endotoxemia

    DEFF Research Database (Denmark)

    Stidsen, Jacob V; Khorooshi, Reza; Rahbek, Martin K U

    2012-01-01

    Pulmonary surfactant protein D (SP-D) is a host defence lectin of the innate immune system that enhances clearance of pathogens and modulates inflammatory responses. Recently it has been found that systemic SP-D is associated with metabolic disturbances and that SP-D deficient mice are mildly obese....... However, the mechanism behind SP-D's role in energy metabolism is not known.Here we report that SP-D deficient mice had significantly higher ad libitum energy intake compared to wild-type mice and unchanged energy expenditure. This resulted in accumulation but also redistribution of fat tissue. Blood...... pressure was unchanged. The change in energy intake was unrelated to the basal levels of hypothalamic Pro-opiomelanocortin (POMC) and Agouti-related peptide (AgRP) gene expression. Neither short time systemic, nor intracereberoventricular SP-D treatment altered the hypothalamic signalling or body weight...

  1. Produksi, isolasi dan karakterisasi enzim dekstranase dari Arthrobacter sp. B7

    Directory of Open Access Journals (Sweden)

    Afaf Baktir

    2012-02-01

    Full Text Available Dextranase enzyme has been purified and characterized from Arthrobacter sp. B7. This enzyme was purified from the culture supernatant of Arthrobacter sp. B7 by procedure of native PAGE. The molecular size of the enzyme was estimated 72,5 kDa by SDSPAGE. The N-terminal amino acid sequence of this enzyme determined using Edman degradation techniques were APVTADVGNLHT. SDS-PAGE and native-PAGE analysis revealed that the enzyme molecule consisted of one sub-unit.

  2. The SARS coronavirus spike glycoprotein is selectively recognized by lung surfactant protein D and activates macrophages

    DEFF Research Database (Denmark)

    Leth-Larsen, Rikke; Zhong, Fei; Chow, Vincent T K

    2007-01-01

    The severe acute respiratory syndrome coronavirus (SARS-CoV) infects host cells with its surface glycosylated spike-protein (S-protein). Here we expressed the SARS-CoV S-protein to investigate its interactions with innate immune mechanisms in the lung. The purified S-protein was detected as a 210 k...

  3. Surfactant Protein A Inhibits Growth and Adherence of UropathogenicEscherichia coliTo Protect the Bladder from Infection.

    Science.gov (United States)

    Hashimoto, Jiro; Takahashi, Motoko; Saito, Atsushi; Murata, Masaki; Kurimura, Yuichiro; Nishitani, Chiaki; Takamiya, Rina; Uehara, Yasuaki; Hasegawa, Yoshihiro; Hiyama, Yoshiki; Sawada, Norimasa; Takahashi, Satoshi; Masumori, Naoya; Kuroki, Yoshio; Ariki, Shigeru

    2017-04-01

    Surfactant protein A (SP-A) is a multifunctional host defense collectin that was first identified as a component of pulmonary surfactant. Although SP-A is also expressed in various tissues, including the urinary tract, its innate immune functions in nonpulmonary tissues are poorly understood. In this study, we demonstrated that adherence of uropathogenic Escherichia coli (UPEC) to the bladder was enhanced in SP-A-deficient mice, which suggests that SP-A plays an important role in innate immunity against UPEC. To understand the innate immune functions of SP-A in detail, we performed in vitro experiments. SP-A directly bound to UPEC in a Ca 2+ -dependent manner, but it did not agglutinate UPEC. Our results suggest that a bouquet-like arrangement seems unsuitable to agglutinate UPEC. Meanwhile, SP-A inhibited growth of UPEC in human urine. Furthermore, the binding of SP-A to UPEC decreased the adherence of bacteria to urothelial cells. These results indicate that direct action of SP-A on UPEC is important in host defense against UPEC. Additionally, adhesion of UPEC to urothelial cells was decreased when the cells were preincubated with SP-A. Adhesion of UPEC to urothelial cells is achieved via interaction between FimH, an adhesin located at bacterial pili, and uroplakin Ia, a glycoprotein expressed on the urothelium. SP-A directly bound to uroplakin Ia and competed with FimH for uroplakin Ia binding. These results lead us to conclude that SP-A plays important roles in host defense against UPEC. Copyright © 2017 by The American Association of Immunologists, Inc.

  4. The impact of surfactant protein-A on ozone-induced changes in the mouse bronchoalveolar lavage proteome

    Directory of Open Access Journals (Sweden)

    Floros Joanna

    2009-03-01

    Full Text Available Abstract Background Ozone is a major component of air pollution. Exposure to this powerful oxidizing agent can cause or exacerbate many lung conditions, especially those involving innate immunity. Surfactant protein-A (SP-A plays many roles in innate immunity by participating directly in host defense as it exerts opsonin function, or indirectly via its ability to regulate alveolar macrophages and other innate immune cells. The mechanism(s responsible for ozone-induced pathophysiology, while likely related to oxidative stress, are not well understood. Methods We employed 2-dimensional difference gel electrophoresis (2D-DIGE, a discovery proteomics approach, coupled with MALDI-ToF/ToF to compare the bronchoalveolar lavage (BAL proteomes in wild type (WT and SP-A knockout (KO mice and to assess the impact of ozone or filtered air on the expression of BAL proteins. Using the PANTHER database and the published literature most identified proteins were placed into three functional groups. Results We identified 66 proteins and focused our analysis on these proteins. Many of them fell into three categories: defense and immunity; redox regulation; and protein metabolism, modification and chaperones. In response to the oxidative stress of acute ozone exposure (2 ppm; 3 hours there were many significant changes in levels of expression of proteins in these groups. Most of the proteins in the redox group were decreased, the proteins involved in protein metabolism increased, and roughly equal numbers of increases and decreases were seen in the defense and immunity group. Responses between WT and KO mice were similar in many respects. However, the percent change was consistently greater in the KO mice and there were more changes that achieved statistical significance in the KO mice, with levels of expression in filtered air-exposed KO mice being closer to ozone-exposed WT mice than to filtered air-exposed WT mice. Conclusion We postulate that SP-A plays a role

  5. Effect of different concentrations of sodium dodecyl sulfate and additional anionic surfactant on properties of low protein natural rubber latex

    Science.gov (United States)

    Abdullah, Nurulhuda; Manaf, Siti Nor Qamarina; Hassan, Aziana Abu

    2017-12-01

    This paper describes the chemical deproteinization process of natural rubber latex (NRL) using chemical denaturants namely urea and sodium dodecyl sulfate (SDS). Commercial high ammoniated natural rubber latex (HANRL) was incubated with both denaturants - urea and SDS for selected period of time before centrifugation and characterization. The role of SDS in NRL deproteinization process was further elucidated by manipulating the concentration of SDS at 0.3 phr and 0.5 phr during the incubation process. It was found that the physical properties of NRL especially stability, were governed by the amount of SDS, whereby higher concentration of SDS used led to greater NRL stability. However, too much concentration of SDS in the system might cause detrimental effect on the properties of low protein NRL. The effects of additional anionic surfactant namely potassium laurate on the physical properties of low protein NRL and its stabilization were also scrutinized. Characterizations include nitrogen determination by Kjeldahl method, zeta potential, and morphological analysis by Field Emission Scanning Electron Microscopy (FESEM).

  6. Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D: Ring Interactions with SP-D Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Crouch,E.; McDonald, B.; Smith, K.; Cararella, T.; Seaton, B.; Head, J.

    2006-01-01

    Surfactant Protein D (SP-D) is an innate immune effector that contributes to antimicrobial host defense and immune regulation. Interactions of SP-D with microorganisms and organic antigens involve binding of glycoconjugates to the C-type lectin carbohydrate recognition domain (CRD). A trimeric fusion protein encoding the human neck+CRD (hNCRD) bound to the aromatic glycoside, p-nitrophenyl-alpha-D-maltoside, with nearly a log-fold higher affinity than maltose, the prototypical competitor. Maltotriose, which has the same linkage pattern as the maltoside, bound with intermediate affinity. Site-directed substitution of leucine for phenylalanine 335 (Phe335) decreased affinities for the maltoside and maltotriose without significantly altering the affinity for maltose or glucose, and substitution of tyrosine or tryptophan for leucine restored preferential binding to maltotriose and the maltoside. A mutant with alanine at this position failed to bind to mannan or maltose-substituted solid supports. Crystallographic analysis of the hNCRD complexed with maltotriose or p-nitrophenyl-maltoside showed stacking of the terminal glucose or nitrophenyl ring with the aromatic ring of Phe335. Our studies indicate that Phe335, which is evolutionarily conserved in all known SP-Ds, plays important - if not critical roles - in SP-D function.

  7. Proteins, polysaccharides, and their complexes used as stabilizers for emulsions: alternatives to synthetic surfactants in the pharmaceutical field?

    Science.gov (United States)

    Bouyer, Eléonore; Mekhloufi, Ghozlene; Rosilio, Véronique; Grossiord, Jean-Louis; Agnely, Florence

    2012-10-15

    Emulsions are widely used in pharmaceutics for the encapsulation, solubilization, entrapment, and controlled delivery of active ingredients. In order to answer the increasing demand for clean label excipients, natural polymers can replace the potentially irritative synthetic surfactants used in emulsion formulation. Indeed, biopolymers are currently used in the food industry to stabilize emulsions, and they appear as promising candidates in the pharmaceutical field too. All proteins and some polysaccharides are able to adsorb at a globule surface, thus decreasing the interfacial tension and enhancing the interfacial elasticity. However, most polysaccharides stabilize emulsions simply by increasing the viscosity of the continuous phase. Proteins and polysaccharides may also be associated either through covalent bonding or electrostatic interactions. The combination of the properties of these biopolymers under appropriate conditions leads to increased emulsion stability. Alternative layers of oppositely charged biopolymers can also be formed around the globules to obtain multi-layered "membranes". These layers can provide electrostatic and steric stabilization thus improving thermal stability and resistance to external treatment. The novel biopolymer-stabilized emulsions have a great potential in the pharmaceutical field for encapsulation, controlled digestion, and targeted release although several challenging issues such as storage and bacteriological concerns still need to be addressed. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Specific cleavage of the lung surfactant protein A by human cathepsin S may impair its antibacterial properties.

    Science.gov (United States)

    Lecaille, Fabien; Naudin, Clément; Sage, Juliette; Joulin-Giet, Alix; Courty, Agnès; Andrault, Pierre-Marie; Veldhuizen, Ruud A W; Possmayer, Fred; Lalmanach, Gilles

    2013-08-01

    Human cysteine cathepsins (Cats) are implicated in lung injuries and tissue remodeling and have recently emerged as important players in pulmonary inflammations. The proteolytic activities of Cat B, L, K, S and H are dramatically increased in the sputum of patients with cystic fibrosis (CF), suggesting a possible involvement in the CF pathophysiology. We found that pulmonary surfactant protein A (SP-A) that participates to innate host defense is extensively degraded in CF expectorations. Breakdown of SP-A was markedly decreased in CF sputum by E-64 and Mu-Leu-Hph-VSPh, a Cat S inhibitor. Cat S cleaved efficiently and specifically SP-A within critical residues of the solvent-exposed loop of its carbohydrate recognition (C-type lectin) domain that allows binding to pathogens. Cat S decreased aggregation properties of SP-A (self-aggregation, aggregation of phospholipid vesicles and rough LPS). Moreover cleavage of SP-A by Cat S reduced binding to yeast mannan and impaired agglutination of Escherichia coli and Pseudomonas aeruginosa, a foremost detrimental pathogen colonizing the lungs of CF patients. Besides human neutrophil serine proteases and bacterial proteases, we propose that Cat S may participate in the pathophysiology of CF by weakening the antibacterial activity of SP-A. More broadly, present results provide further indication that Cat S, along with Cats B and L, could display immuno-modulatory functions by inactivating key proteins involved in the innate immunity defense. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Optimization of Variable Ventilation for Physiology, Immune Response and Surfactant Enhancement in Preterm Lambs

    Directory of Open Access Journals (Sweden)

    Erzsébet Bartolák-Suki

    2017-06-01

    Full Text Available Preterm infants often require mechanical ventilation due to lung immaturity including reduced or abnormal surfactant. Since cyclic stretch with cycle-by-cycle variability is known to augment surfactant release by epithelial cells, we hypothesized that such in vivo mechanotransduction improves surfactant maturation and hence lung physiology in preterm subjects. We thus tested whether breath-by-breath variability in tidal volume (VT in variable ventilation (VV can be tuned for optimal performance in a preterm lamb model. Preterm lambs were ventilated for 3 h with conventional ventilation (CV or two variants of VV that used a maximum VT of 1.5 (VV1 or 2.25 (VV2 times the mean VT. VT was adjusted during ventilation to a permissive pCO2 target range. Respiratory mechanics were monitored continuously using the forced oscillation technique, followed by postmortem bronchoalveolar lavage and tissue collection. Both VVs outperformed CV in blood gas parameters (pH, SaO2, cerebral O2 saturation. However, only VV2 lowered PaCO2 and had a higher specific respiratory compliance than CV. VV2 also increased surfactant protein (SP-B release compared to VV1 and stimulated its production compared to CV. The production and release of proSP-C however, was increased with CV compared to both VVs. There was more SP-A in both VVs than CV in the lung, but VV2 downregulated SP-A in the lavage, whereas SP-D significantly increased in CV in both the lavage and lung. Compared to CV, the cytokines IL-1β, and TNFα decreased with both VVs with less inflammation during VV2. Additionally, VV2 lungs showed the most homogeneous alveolar structure and least inflammatory cell infiltration assessed by histology. CV lungs exhibited over-distension mixed with collapsed and interstitial edematous regions with occasional hemorrhage. Following VV1, some lambs had normal alveolar structure while others were similar to CV. The IgG serum proteins in the lavage, a marker of leakage, were the

  10. Optimization of Variable Ventilation for Physiology, Immune Response and Surfactant Enhancement in Preterm Lambs.

    Science.gov (United States)

    Bartolák-Suki, Erzsébet; Noble, Peter B; Bou Jawde, Samer; Pillow, Jane J; Suki, Béla

    2017-01-01

    Preterm infants often require mechanical ventilation due to lung immaturity including reduced or abnormal surfactant. Since cyclic stretch with cycle-by-cycle variability is known to augment surfactant release by epithelial cells, we hypothesized that such in vivo mechanotransduction improves surfactant maturation and hence lung physiology in preterm subjects. We thus tested whether breath-by-breath variability in tidal volume (V T ) in variable ventilation (VV) can be tuned for optimal performance in a preterm lamb model. Preterm lambs were ventilated for 3 h with conventional ventilation (CV) or two variants of VV that used a maximum V T of 1.5 (VV1) or 2.25 (VV2) times the mean V T . V T was adjusted during ventilation to a permissive pCO 2 target range. Respiratory mechanics were monitored continuously using the forced oscillation technique, followed by postmortem bronchoalveolar lavage and tissue collection. Both VVs outperformed CV in blood gas parameters (pH, Sa O 2 , cerebral O 2 saturation). However, only VV2 lowered PaCO 2 and had a higher specific respiratory compliance than CV. VV2 also increased surfactant protein (SP)-B release compared to VV1 and stimulated its production compared to CV. The production and release of proSP-C however, was increased with CV compared to both VVs. There was more SP-A in both VVs than CV in the lung, but VV2 downregulated SP-A in the lavage, whereas SP-D significantly increased in CV in both the lavage and lung. Compared to CV, the cytokines IL-1β, and TNFα decreased with both VVs with less inflammation during VV2. Additionally, VV2 lungs showed the most homogeneous alveolar structure and least inflammatory cell infiltration assessed by histology. CV lungs exhibited over-distension mixed with collapsed and interstitial edematous regions with occasional hemorrhage. Following VV1, some lambs had normal alveolar structure while others were similar to CV. The IgG serum proteins in the lavage, a marker of leakage, were the

  11. Surfactant gene polymorphisms and interstitial lung diseases

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    Pantelidis Panagiotis

    2001-11-01

    Full Text Available Abstract Pulmonary surfactant is a complex mixture of phospholipids and proteins, which is present in the alveolar lining fluid and is essential for normal lung function. Alterations in surfactant composition have been reported in several interstitial lung diseases (ILDs. Furthermore, a mutation in the surfactant protein C gene that results in complete absence of the protein has been shown to be associated with familial ILD. The role of surfactant in lung disease is therefore drawing increasing attention following the elucidation of the genetic basis underlying its surface expression and the proof of surfactant abnormalities in ILD.

  12. Complete Genomic Structure of the Cultivated Rice Endophyte Azospirillum sp. B510

    Science.gov (United States)

    Kaneko, Takakazu; Minamisawa, Kiwamu; Isawa, Tsuyoshi; Nakatsukasa, Hiroki; Mitsui, Hisayuki; Kawaharada, Yasuyuki; Nakamura, Yasukazu; Watanabe, Akiko; Kawashima, Kumiko; Ono, Akiko; Shimizu, Yoshimi; Takahashi, Chika; Minami, Chiharu; Fujishiro, Tsunakazu; Kohara, Mitsuyo; Katoh, Midori; Nakazaki, Naomi; Nakayama, Shinobu; Yamada, Manabu; Tabata, Satoshi; Sato, Shusei

    2010-01-01

    We determined the nucleotide sequence of the entire genome of a diazotrophic endophyte, Azospirillum sp. B510. Strain B510 is an endophytic bacterium isolated from stems of rice plants (Oryza sativa cv. Nipponbare). The genome of B510 consisted of a single chromosome (3 311 395 bp) and six plasmids, designated as pAB510a (1 455 109 bp), pAB510b (723 779 bp), pAB510c (681 723 bp), pAB510d (628 837 bp), pAB510e (537 299 bp), and pAB510f (261 596 bp). The chromosome bears 2893 potential protein-encoding genes, two sets of rRNA gene clusters (rrns), and 45 tRNA genes representing 37 tRNA species. The genomes of the six plasmids contained a total of 3416 protein-encoding genes, seven sets of rrns, and 34 tRNAs representing 19 tRNA species. Eight genes for plasmid-specific tRNA species are located on either pAB510a or pAB510d. Two out of eight genomic islands are inserted in the plasmids, pAB510b and pAB510e, and one of the islands is inserted into trnfM-CAU in the rrn located on pAB510e. Genes other than the nif gene cluster that are involved in N2 fixation and are homologues of Bradyrhizobium japonicum USDA110 include fixABCX, fixNOQP, fixHIS, fixG, and fixLJK. Three putative plant hormone-related genes encoding tryptophan 2-monooxytenase (iaaM) and indole-3-acetaldehyde hydrolase (iaaH), which are involved in IAA biosynthesis, and ACC deaminase (acdS), which reduces ethylene levels, were identified. Multiple gene-clusters for tripartite ATP-independent periplasmic-transport systems and a diverse set of malic enzymes were identified, suggesting that B510 utilizes C4-dicarboxylate during its symbiotic relationship with the host plant. PMID:20047946

  13. Complete genomic structure of the cultivated rice endophyte Azospirillum sp. B510.

    Science.gov (United States)

    Kaneko, Takakazu; Minamisawa, Kiwamu; Isawa, Tsuyoshi; Nakatsukasa, Hiroki; Mitsui, Hisayuki; Kawaharada, Yasuyuki; Nakamura, Yasukazu; Watanabe, Akiko; Kawashima, Kumiko; Ono, Akiko; Shimizu, Yoshimi; Takahashi, Chika; Minami, Chiharu; Fujishiro, Tsunakazu; Kohara, Mitsuyo; Katoh, Midori; Nakazaki, Naomi; Nakayama, Shinobu; Yamada, Manabu; Tabata, Satoshi; Sato, Shusei

    2010-02-01

    We determined the nucleotide sequence of the entire genome of a diazotrophic endophyte, Azospirillum sp. B510. Strain B510 is an endophytic bacterium isolated from stems of rice plants (Oryza sativa cv. Nipponbare). The genome of B510 consisted of a single chromosome (3,311,395 bp) and six plasmids, designated as pAB510a (1,455,109 bp), pAB510b (723,779 bp), pAB510c (681,723 bp), pAB510d (628,837 bp), pAB510e (537,299 bp), and pAB510f (261,596 bp). The chromosome bears 2893 potential protein-encoding genes, two sets of rRNA gene clusters (rrns), and 45 tRNA genes representing 37 tRNA species. The genomes of the six plasmids contained a total of 3416 protein-encoding genes, seven sets of rrns, and 34 tRNAs representing 19 tRNA species. Eight genes for plasmid-specific tRNA species are located on either pAB510a or pAB510d. Two out of eight genomic islands are inserted in the plasmids, pAB510b and pAB510e, and one of the islands is inserted into trnfM-CAU in the rrn located on pAB510e. Genes other than the nif gene cluster that are involved in N(2) fixation and are homologues of Bradyrhizobium japonicum USDA110 include fixABCX, fixNOQP, fixHIS, fixG, and fixLJK. Three putative plant hormone-related genes encoding tryptophan 2-monooxytenase (iaaM) and indole-3-acetaldehyde hydrolase (iaaH), which are involved in IAA biosynthesis, and ACC deaminase (acdS), which reduces ethylene levels, were identified. Multiple gene-clusters for tripartite ATP-independent periplasmic-transport systems and a diverse set of malic enzymes were identified, suggesting that B510 utilizes C(4)-dicarboxylate during its symbiotic relationship with the host plant.

  14. Sex differences in the response of the alveolar macrophage proteome to treatment with exogenous surfactant protein-A

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    Phelps David S

    2012-07-01

    Full Text Available Abstract Background Male wild type (WT C57BL/6 mice are less capable of clearing bacteria and surviving from bacterial pneumonia than females. However, if an oxidative stress (acute ozone exposure occurs before infection, the advantage shifts to males who then survive at higher rates than females. We have previously demonstrated that survival in surfactant protein-A (SP-A knockout (KO mice compared to WT was significantly reduced. Because the alveolar macrophage (AM is pivotal in host defense we hypothesized that SP-A and circulating sex hormones are responsible for these sex differences. We used 2D-DIGE to examine the relationship of sex and SP-A on the AM proteome. The role of SP-A was investigated by treating SP-A KO mice with exogenous SP-A for 6 and 18 hr and studying its effects on the AM proteome. Results We found: 1 less variance between KO males and females than between the WT counterparts by principal component analysis, indicating that SP-A plays a role in sex differences; 2 fewer changes in females when the total numbers of significantly changing protein spots or identified whole proteins in WT or 18 hr SP-A-treated males or females were compared to their respective KO groups; 3 more proteins with functions related to chaperones or protease balance and Nrf2-regulated proteins changed in response to SP-A in females than in males; and 4 the overall pattern of SP-A induced changes in actin-related proteins were similar in both sexes, although males had more significant changes. Conclusions Although there seems to be an interaction between sex and the effect of SP-A, it is unclear what the responsible mechanisms are. However, we found that several of the proteins that were expressed at significantly higher levels in females than in males in WT and/or in KO mice are known to interact with the estrogen receptor and may thus play a role in the SP-A/sex interaction. These include major vault protein, chaperonin subunit 2 (beta (CCT2, and Rho

  15. Maillard Conjugation of Sodium Alginate to Whey Protein for Enhanced Resistance to Surfactant-Induced Competitive Displacement from Air-Water Interfaces.

    Science.gov (United States)

    Cai, Bingqing; Saito, Anna; Ikeda, Shinya

    2018-01-24

    Whey protein adsorbed to an interface forms a viscoelastic interfacial film but is displaced competitively from the interface by a small-molecule surfactant added afterward. The present study evaluated the impact of the covalent conjugation of high- or low-molecular-weight sodium alginate (HA or LA) to whey protein isolate (WPI) via the Maillard reaction on the ability of whey protein to resist surfactant-induced competitive displacement from the air-water interface. Surfactant added after the pre-adsorption of conjugate to the interface increased surface pressure. At a given surface pressure, the WPI-LA conjugate showed a significantly higher interfacial area coverage and lower interfacial film thickness compared to those of the WPI-HA conjugate or unconjugated WPI. The addition of LA to the aqueous phase had little effect on the interfacial area and thickness of pre-adsorbed WPI. These results suggest the importance of the molecular weight of the polysaccharide moiety in determining interfacial properties of whey protein-alginate conjugates.

  16. Molecular Characteristics and Biological Functions of Surface-Active and Surfactant Proteins.

    Science.gov (United States)

    Sunde, Margaret; Pham, Chi L L; Kwan, Ann H

    2017-06-20

    Many critical biological processes take place at hydrophobic:hydrophilic interfaces, and a wide range of organisms produce surface-active proteins and peptides that reduce surface and interfacial tension and mediate growth and development at these boundaries. Microorganisms produce both small lipid-associated peptides and amphipathic proteins that allow growth across water:air boundaries, attachment to surfaces, predation, and improved bioavailability of hydrophobic substrates. Higher-order organisms produce surface-active proteins with a wide variety of functions, including the provision of protective foam environments for vulnerable reproductive stages, evaporative cooling, and gas exchange across airway membranes. In general, the biological functions supported by these diverse polypeptides require them to have an amphipathic nature, and this is achieved by a diverse range of molecular structures, with some proteins undergoing significant conformational change or intermolecular association to generate the structures that are surface active.

  17. Altered surfactant homeostasis and recurrent respiratory failure secondary to TTF-1 nuclear targeting defect

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    Carnielli Virgilio P

    2011-08-01

    and was not found in two healthy controls and in five ABCA3 mutation carriers. Kinetic studies demonstrated a marked reduction of SP-B synthesis (43.2 vs. 76.5 ± 24.8%/day; conversely, DSPC synthesis was higher (12.4 vs. 6.3 ± 0.5%/day compared to controls, although there was a marked reduction of DSPC content in tracheal aspirates (29.8 vs. 56.1 ± 12.4% of total phospholipid content. Conclusion Defective TTF-1 signaling may result in profound surfactant homeostasis disruption and neonatal/pediatric diffuse lung disease. Heterozygous ABCA3 missense mutations may act as disease modifiers in other genetic surfactant defects.

  18. Metabolic networks and bioenergetics of Aurantiochytrium sp. B-072 during storage lipid formation

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    Montri Chaisawang

    2012-09-01

    Full Text Available Baffled shake flask cultivation of Aurantiochytrium sp. B-072 was carried out at in a glucose-monosodium glutamate mineral medium at different C/N-ratios (30-165 with glucose fixed at 90 g/L. With increasing C/N-ratio, a modest increase in lipid content (60 to 73 % w/w was observed whereas fat-free biomass decreased but overall biomass showed little variation. FA-profiles were not affected to a large extent by C/N-ratio and absolute docosahexaenoic (DHA-levels fell in narrow range (5-6 g/L. However at C/N > 64 a rapid decrease in lipid synthetic rate and/or incomplete glucose utilization occurred. Glucose and FA-fluxes based on fat-free biomass peaked at a C/N ratio of 56. This condition was chosen for calculation of the redox balance (NAD(PH and energy (ATP requirement and to estimate the in vivo P/O ratio during the main period of fatty acid biosynthesis. Several models with different routes for NADPH, acetyl-CoA formation and re-oxidation of OAA formed via ATP-citrate lyase were considered as these influence the redox- and energy balance. As an example, using a commonly shown scheme whereby NADPH is supplied by a cytosolic "transhydrogenase cycle" (pyruvate-OAA-malate-pyruvate and OAA formed by ATP-citrate lyase is recycled via import into the mitochondria as malate, the calculated NADPH-requirement amounted to 5.5 with an ATP-demand of 10.5 mmol/(g fat-free biomass x h and an in vivo P/O-ratio (not including non-growth associated maintenance of 1.6. The lowest ATP requirement is found when acetyl-CoA would be transported directly from the mitochondria to the cytosol by carnitine acetyltransferase. Assay of some enzymes critical for NADPH supply indicates that activity of glucose-6-phosphate dehydrogenase, the first enzyme in the HMP pathway, is far insufficient for the required NADPH-flux and malic enzyme must be a major source. Activity of the latter (ca. 300 mU/mg protein far exceeds that in oleaginous fungi and yeast.

  19. Effects of colonization of a bacterial endophyte, Azospirillum sp. B510, on disease resistance in tomato.

    Science.gov (United States)

    Fujita, Moeka; Kusajima, Miyuki; Okumura, Yasuko; Nakajima, Masami; Minamisawa, Kiwamu; Nakashita, Hideo

    2017-08-01

    A plant growth-promoting bacteria, Azospirillum sp. B510, isolated from rice, can enhance growth and yield and induce disease resistance against various types of diseases in rice. Because little is known about the interaction between other plant species and this strain, we have investigated the effect of its colonization on disease resistance in tomato plants. Treatment with this strain by soil-drenching method established endophytic colonization in root tissues in tomato plant. The endophytic colonization with this strain-induced disease resistance in tomato plant against bacterial leaf spot caused by Pseudomonas syringae pv. tomato and gray mold caused by Botrytis cinerea. In Azospirillum-treated plants, neither the accumulation of SA nor the expression of defense-related genes was observed. These indicate that endophytic colonization with Azospirillum sp. B510 is able to activate the innate immune system also in tomato, which does not seem to be systemic acquired resistance.

  20. Surfactant Protein D Binds to Coxiella burnetii and Results in a Decrease in Interactions with Murine Alveolar Macrophages.

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    Kelly A Soltysiak

    Full Text Available Coxiella burnetii is a Gram-negative, obligate intracellular bacterium and the causative agent of Q fever. Infections are usually acquired after inhalation of contaminated particles, where C. burnetii infects its cellular target cells, alveolar macrophages. Respiratory pathogens encounter the C-type lectin surfactant protein D (SP-D during the course of natural infection. SP-D is a component of the innate immune response in the lungs and other mucosal surfaces. Many Gram-negative pulmonary pathogens interact with SP-D, which can cause aggregation, bactericidal effects and aid in bacterial clearance. Here we show that SP-D binds to C. burnetii in a calcium-dependent manner with no detectable bacterial aggregation or bactericidal effects. Since SP-D interactions with bacteria often alter macrophage interactions, it was determined that SP-D treatment resulted in a significant decrease in C. burnetii interactions to a mouse alveolar macrophage model cell line MH-S indicating SP-D causes a significant decrease in phagocytosis. The ability of SP-D to modulate macrophage activation by C. burnetii was tested and it was determined that SP-D does not alter the correlates measured for macrophage activation. Taken together these studies support those demonstrating limited activation of alveolar macrophages with C. burnetii and demonstrate interactions with SP-D participate in reduction of phagocyte attachment and phagocytosis.

  1. Fungal melanin stimulates surfactant protein D-mediated opsonization of and host immune response to Aspergillus fumigatus spores.

    Science.gov (United States)

    Sze Wah Wong, Sarah; Rani, Manjusha; Dodagatta-Marri, Eswari; Ibrahim-Granet, Oumaima; Kishore, Uday; Bayry, Jagadeesh; Latgé, Jean-Paul; Sahu, Arvind; Madan, Taruna; Aimanianda, Vishukumar

    2018-02-05

    Surfactant protein D (SP-D), a C-type lectin and pattern-recognition soluble factor, plays an important role in immune surveillance to detect and eliminate human pulmonary pathogens. SPD has been shown to protect against infections with the most ubiquitous airborne fungal pathogen, Aspergillus fumigatus, but the fungal surface component(s) interacting with SP-D is unknown. Here, we show that SP-D binds to melanin pigment on the surface of A. fumigatus dormant spores (conidia). SP-D also exhibited an affinity to two cell-wall polysaccharides of A. fumigatus, galactomannan (GM) and galactosaminogalactan (GAG). The immunolabeling pattern of SP-D was punctate on the conidial surface and was uniform on germinating conidia, in accordance with the localization of melanin, GM, and GAG. We also found that the collagen-like domain of SP-D is involved in its interaction with melanin, whereas its carbohydrate-recognition domain recognized GM and GAG. Unlike unopsonized conidia, SPD-opsonized conidia were phagocytosed more efficiently and stimulated the secretion of proinflammatory cytokines by human monocytederived macrophages. Further, SP-D -/- mice challenged intranasally with wild-type conidia or melanin ghosts (i.e. hollow melanin spheres) displayed significantly reduced proinflammatory cytokines in the lung compared with wild-type mice. In summary, SP-D binds to melanin present on the dormant A. fumigatus conidial surface, facilitates conidial phagocytosis, and stimulates the host immune response. Copyright © 2018, The American Society for Biochemistry and Molecular Biology.

  2. Human autoantibodies against Clq: lack of cross reactivity with the collectins mannan-binding protein, lung surfactant protein A and bovine conglutinin.

    Science.gov (United States)

    Mårtensson, U; Thiel, S; Jensenius, J C; Sjöholm, A G

    1996-03-01

    The collectins, a group of humoral C-type lectins, have globular and collagen-like regions and share structural features with the complement protein C1q. The question was asked if autoantibodies to the collagen-like region of C1q (anti-C1qCLR) might cross-react with collectins, such as mannan-binding protein (MBP), lung surfactant protein A (SP-A) and bovine conglutinin (BK). Anti-C1qCLR antibodies of the systemic lupus erythematosus (SLE) type and anti-C1qCLR antibodies of the hypocomplementemic urticarial vasculitis syndrome (HUVS) type were investigated. Cross-absorption and elution experiments combined with antibody detection by enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis gave no evidence of cross-reactive anti-C1qCLR antibodies. However, one serum with HUVS type anti-C1qCLR antibodies contained anti-MBP antibodies that were cross-reactive with SP-A. Judging from results of ELISA inhibition experiments and immunoblot analysis, four SLE sera contained antibodies to native BK, while two sera with HUVS type anti-C1qCLR antibodies contained antibodies to epitopes of denatured BK. This might imply that autoimmunity to collagen-like structures is not restricted to C1qCLR in HUVS and HUVS/SLE overlap syndromes.

  3. Alterations of the murine gut microbiome in allergic airway disease are independent of surfactant protein D

    DEFF Research Database (Denmark)

    Barfod, Kenneth Klingenberg; Roggenbuck, Michael; Al-Shuweli, Suzan

    2017-01-01

    with the lack of SP-D protein and presence of allergic airway disease in the widely used SP-D-deficient mouse model. Results We describe here for the first time the lung and gut microbiota of the SP-D mouse model with OVA induced allergic airway disease. After the challenge animals were killed and fecal samples...

  4. Biodegradation of kraft lignin by a bacterial strain Comamonas sp. B-9 isolated from eroded bamboo slips.

    Science.gov (United States)

    Chen, Y H; Chai, L Y; Zhu, Y H; Yang, Z H; Zheng, Y; Zhang, H

    2012-05-01

    The aim was to obtain evidences for lignin degradation by unicellular bacterium Comamonas sp. B-9. Comamonas sp. B-9 was inoculated into kraft lignin-mineral salt medium (KL-MSM) at pH 7·0 and 30°C for 7 days of incubation. The bacterial growth, chemical oxygen demand (COD) reduction, secretion of ligninolytic enzymes and productions of low-molecular-weight compounds revealed that Comamonas sp. B-9 was able to degrade kraft lignin (KL). COD in KL-MSM reduced by 32% after 7 days of incubation. The maximum activities of manganese peroxidase (MnP) of 2903·2 U l(-1) and laccase (Lac) of 1250 U l(-1) were observed at 4th and 6th day, respectively. The low-molecular-weight compounds such as ethanediol, 3, 5-dimethyl-benzaldehyde and phenethyl alcohol were formed in the degradation of KL by Comamonas sp. B-9 based on GC-MS analysis. This study confirmed that Comamonas sp. B-9 could utilize KL as a sole carbon source and degrade KL to low-molecular-weight compounds. Comamonas sp. B-9 may be useful in the utilization and bioconversion of lignin and lignin-derived aromatic compounds in biotechnological applications. Meanwhile, using Comamonas sp. B-9 in treatment of wastewater in pulp and paper industry is a meaningful work. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  5. Surfactant protein D (SP-D) deficiency is attenuated in humanised mice expressing the Met(11)Thr short nucleotide polymorphism of SP-D: implications for surfactant metabolism in the lung

    Science.gov (United States)

    Knudsen, Lars; Ochs, Katharina; Boxler, Laura; Tornoe, Ida; Lykke-Sorensen, Grith; Mackay, Rose-Marie; Clark, Howard W; Holmskov, Uffe; Ochs, Matthias; Madsen, Jens

    2013-01-01

    Surfactant protein D (SP-D) is part of the innate immune system involved in lung homeostasis. SP-D knockout mice show accumulations of foamy alveolar macrophages, alveolar lipoproteinosis and pulmonary emphysema. Three single nucleotide polymorphisms (SNPs) have been described in the coding sequence of the human SP-D gene SFTPD. Clinical studies showed that the SNP SFTPD with a nucleotide change from A to C resulting in a Met to Thr substitution at position 11 in the protein (Met(11)Thr), is relevant. This study set out to create a humanised mouse model of the Met(11)Thr SNP. Transgenic mice lines expressing either Met(11) or Thr(11) SP-D under the control of the ubiquitously expressed pROSA26 promoter in C57Bl/6 SP-D deficient mice (DKO) was created. Both Met(11) (142 ± 52 ng mL−1) and Thr(11) (228 ± 76 ng mL−1) mice lines expressed human SP-D at almost similar levels. According to the literature this was within the range of SP-D levels found in wildtype (WT) mice (253 ± 22 ng mL−1). Met(11) or Thr(11) SP-D in serum from transgenic mice bound maltose in a calcium-dependent manner, and binding was inhibited in the presence of EDTA or maltose. Bronchoalveolar lavage showed for both transgenic mice lines complementation of the DKO phenotype by restoring cell counts, phospholipid levels and protein content back to WT levels. Cytospins of BAL pellet cells showed a resemblance to WT but both mice lines showed some foamy alveolar macrophages. The stereological analysis showed for none of the mice lines a complete abrogation of emphysematous alterations. However, both Met(11) and Thr(11) mice lines were partially reverted back to a WT phenotype when compared with DKO mice, indicating important effects on surfactant metabolism in vivo. PMID:24111992

  6. Surfactant protein-A modulates LPS-induced TLR4 localization and signaling via β-arrestin 2.

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    Vicky Sender

    Full Text Available The soluble C-type lectin surfactant protein (SP-A mediates lung immune responses partially via its direct effects on alveolar macrophages (AM, the main resident leukocytes exposed to antigens. SP-A modulates the AM threshold of lipopolysaccharide (LPS activity towards an anti-inflammatory phenotype both in vitro and in vivo through various mechanisms. LPS responses are tightly regulated via distinct pathways including subcellular TLR4 localization and thus ligand sensing. The cytosolic scaffold and signaling protein β-arrestin 2 acts as negative regulator of LPS-induced TLR4 activation. Here we show that SP-A neither increases TLR4 abundancy nor co-localizes with TLR4 in primary AM. SP-A significantly reduces the LPS-induced co-localization of TLR4 with the early endosome antigen (EEA 1 by promoting the co-localization of TLR4 with the post-Golgi compartment marker Vti1b in freshly isolated AM from rats and wild-type (WT mice, but not in β-arrestin 2(-/- AM. Compared to WT mice pulmonary LPS-induced TNF-α release in β-arrestin 2(-/- mice is accelerated and enhanced and exogenous SP-A fails to inhibit both lung LPS-induced TNF-α release and TLR4/EEA1 positioning. SP-A, but not LPS, enhances β-arrestin 2 protein expression in a time-dependent manner in primary rat AM. The constitutive expression of β-arrestin 2 in AM from SP-A(-/- mice is significantly reduced compared to SP-A(+/+ mice and is rescued by SP-A. Prolonged endosome retention of LPS-induced TLR4 in AM from SP-A(-/- mice is restored by exogenous SP-A, and is antagonized by β-arrestin 2 blocking peptides. LPS induces β-arrestin 2/TLR4 association in primary AM which is further enhanced by SP-A. The data demonstrate that SP-A modulates LPS-induced TLR4 trafficking and signaling in vitro and in vivo engaging β-arrestin 2.

  7. Surfactant protein d deficiency in mice is associated with hyperphagia, altered fat deposition, insulin resistance, and increased basal endotoxemia.

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    Jacob V Stidsen

    Full Text Available Pulmonary surfactant protein D (SP-D is a host defence lectin of the innate immune system that enhances clearance of pathogens and modulates inflammatory responses. Recently it has been found that systemic SP-D is associated with metabolic disturbances and that SP-D deficient mice are mildly obese. However, the mechanism behind SP-D's role in energy metabolism is not known.Here we report that SP-D deficient mice had significantly higher ad libitum energy intake compared to wild-type mice and unchanged energy expenditure. This resulted in accumulation but also redistribution of fat tissue. Blood pressure was unchanged. The change in energy intake was unrelated to the basal levels of hypothalamic Pro-opiomelanocortin (POMC and Agouti-related peptide (AgRP gene expression. Neither short time systemic, nor intracereberoventricular SP-D treatment altered the hypothalamic signalling or body weight accumulation.In ad libitum fed animals, serum leptin, insulin, and glucose were significantly increased in mice deficient in SP-D, and indicative of insulin resistance. However, restricted diets eliminated all metabolic differences except the distribution of body fat. SP-D deficiency was further associated with elevated levels of systemic bacterial lipopolysaccharide.In conclusion, our findings suggest that lack of SP-D mediates modulation of food intake not directly involving hypothalamic regulatory pathways. The resulting accumulation of adipose tissue was associated with insulin resistance. The data suggest SP-D as a regulator of energy intake and body composition and an inhibitor of metabolic endotoxemia. SP-D may play a causal role at the crossroads of inflammation, obesity, and insulin resistance.

  8. Surfactant Protein D Inhibits Adherence of Uropathogenic Escherichia coli to the Bladder Epithelial Cells and the Bacterium-induced Cytotoxicity

    Science.gov (United States)

    Kurimura, Yuichiro; Nishitani, Chiaki; Ariki, Shigeru; Saito, Atsushi; Hasegawa, Yoshihiro; Takahashi, Motoko; Hashimoto, Jiro; Takahashi, Satoshi; Tsukamoto, Taiji; Kuroki, Yoshio

    2012-01-01

    The adherence of uropathogenic Escherichia coli (UPEC) to the host urothelial surface is the first step for establishing UPEC infection. Uroplakin Ia (UPIa), a glycoprotein expressed on bladder urothelium, serves as a receptor for FimH, a lectin located at bacterial pili, and their interaction initiates UPEC infection. Surfactant protein D (SP-D) is known to be expressed on mucosal surfaces in various tissues besides the lung. However, the functions of SP-D in the non-pulmonary tissues are poorly understood. The purposes of this study were to investigate the possible function of SP-D expressed in the bladder urothelium and the mechanisms by which SP-D functions. SP-D was expressed in human bladder mucosa, and its mRNA was increased in the bladder of the UPEC infection model in mice. SP-D directly bound to UPEC and strongly agglutinated them in a Ca2+-dependent manner. Co-incubation of SP-D with UPEC decreased the bacterial adherence to 5637 cells, the human bladder cell line, and the UPEC-induced cytotoxicity. In addition, preincubation of SP-D with 5637 cells resulted in the decreased adherence of UPEC to the cells and in a reduced number of cells injured by UPEC. SP-D directly bound to UPIa and competed with FimH for UPIa binding. Consistent with the in vitro data, the exogenous administration of SP-D inhibited UPEC adherence to the bladder and dampened UPEC-induced inflammation in mice. These results support the conclusion that SP-D can protect the bladder urothelium against UPEC infection and suggest a possible function of SP-D in urinary tract. PMID:23012359

  9. Surfactant Protein A and Napsin A in the Immunohistochemical Characterization of Canine Pulmonary Carcinomas: Comparison With Thyroid Transcription Factor-1.

    Science.gov (United States)

    Beck, Jessica; Miller, Margaret A; Frank, Chad; DuSold, Dee; Ramos-Vara, José Antonio

    2017-09-01

    Thyroid transcription factor-1 (TTF-1) is a specific and sensitive marker for canine pulmonary tumors but is also expressed in thyroid carcinomas, which commonly metastasize to lung. Napsin A and surfactant protein A (SP-A) are used in the histologic diagnosis of non-small-cell lung cancer in humans but have not been thoroughly evaluated in neoplasms of dogs. The objective of this study was to compare the efficacy of immunohistochemistry for SP-A, napsin A, and TTF-1 in the diagnosis of canine pulmonary carcinomas. TTF-1, napsin A, and SP-A antibodies were applied to 67 formalin-fixed, paraffin-embedded canine pulmonary tumors. Although each marker had good sensitivity, only 3% (2/67) of lung tumors were negative for SP-A compared with 7% (5/67) and 9% (6/67) for napsin A and TTF-1, respectively. Each antigen was detected in a greater percentage of cells of tumors with acinar or papillary patterns compared with those with squamous differentiation. SP-A immunoreactivity was absent in all 113 nonpulmonary tumors tested. Of 108 normal tissues, SP-A was detected only in lung and in 1 of 6 adrenal, 1 of 3 endometrial, and 1 of 4 hepatic sections. Based on these findings, SP-A and napsin A are useful markers of canine lung epithelial neoplasia. Of these, SP-A is the most sensitive and specific (a possible pitfall is the need to distinguish entrapped normal pulmonary epithelial cells or alveolar macrophages from neoplastic cells) and can be used in combination with TTF-1 or napsin A to improve detection and differentiation of pulmonary carcinomas from metastatic tumors in the canine lung.

  10. Common genetic variants of surfactant protein-D (SP-D are associated with type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Neus Pueyo

    Full Text Available CONTEXT: Surfactant protein-D (SP-D is a primordial component of the innate immune system intrinsically linked to metabolic pathways. We aimed to study the association of single nucleotide polymorphisms (SNPs affecting SP-D with insulin resistance and type 2 diabetes (T2D. RESEARCH DESIGN AND METHODS: We evaluated a common genetic variant located in the SP-D coding region (rs721917, Met(31Thr in a sample of T2D patients and non-diabetic controls (n = 2,711. In a subset of subjects (n = 1,062, this SNP was analyzed in association with circulating SP-D concentrations, insulin resistance, and T2D. This SNP and others were also screened in the publicly available Genome Wide Association (GWA database of the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC. RESULTS: We found the significant association of rs721917 with circulating SP-D, parameters of insulin resistance and T2D. Indeed, G carriers showed decreased circulating SP-D (p = 0.004, decreased fasting glucose (p = 0.0002, glycated hemoglobin (p = 0.0005, and 33% (p = 0.002 lower prevalence of T2D, estimated under a dominant model, especially among women. Interestingly, these differences remained significant after controlling for origin, age, gender, and circulating SP-D. Moreover, this SNP and others within the SP-D genomic region (i.e. rs10887344 were significantly associated with quantitative measures of glucose homeostasis, insulin sensitivity, and T2D, according to GWAS datasets from MAGIC. CONCLUSIONS: SP-D gene polymorphisms are associated with insulin resistance and T2D. These associations are independent of circulating SP-D concentrations.

  11. High-resolution structure of a BRICHOS domain and its implications for anti-amyloid chaperone activity on lung surfactant protein C

    OpenAIRE

    Willander, Hanna; Askarieh, Glareh; Landreh, Michael; Westermark, Per; Nordling, Kerstin; Keränen, Henrik; Hermansson, Erik; Hamvas, Aaron; Nogee, Lawrence M.; Bergman, Tomas; Saenz, Alejandra; Casals, Cristina; Åqvist, Johan; Jörnvall, Hans; Berglund, Helena

    2012-01-01

    BRICHOS domains are encoded in > 30 human genes, which are associated with cancer, neurodegeneration, and interstitial lung disease (ILD). The BRICHOS domain from lung surfactant protein C proprotein (proSP-C) is required for membrane insertion of SP-C and has anti-amyloid activity in vitro. Here, we report the 2.1 Å crystal structure of the human proSP-C BRICHOS domain, which, together with molecular dynamics simulations and hydrogen-deuterium exchange mass spectrometry, reveals how BRICHOS ...

  12. CRP-ductin, the mouse homologue of gp-340/deleted in malignant brain tumors 1 (DMBT1), binds gram-positive and gram-negative bacteria and interacts with lung surfactant protein D

    DEFF Research Database (Denmark)

    Madsen, Jens; Tornøe, Ida; Nielsen, Ole

    2003-01-01

    CRP-ductin is a protein expressed mainly by mucosal epithelial cells in the mouse. Sequence homologies indicate that CRP-ductin is the mouse homologue of human gp-340, a glycoprotein that agglutinates microorganisms and binds the lung mucosal collectin surfactant protein-D (SP-D). Here we report ...

  13. Effect of irradiation/bone marrow transplantation on alveolar epithelial type II cells is aggravated in surfactant protein D deficient mice.

    Science.gov (United States)

    Mühlfeld, Christian; Madsen, Jens; Mackay, Rose-Marie; Schneider, Jan Philipp; Schipke, Julia; Lutz, Dennis; Birkelbach, Bastian; Knudsen, Lars; Botto, Marina; Ochs, Matthias; Clark, Howard

    2017-01-01

    Irradiation followed by bone marrow transplantation (BM-Tx) is a frequent therapeutic intervention causing pathology to the lung. Although alveolar epithelial type II (AE2) cells are essential for lung function and are damaged by irradiation, the long-term consequences of irradiation and BM-Tx are not well characterized. In addition, it is unknown whether surfactant protein D (SP-D) influences the response of AE2 cells to the injurious events. Therefore, wildtype (WT) and SP-D -/- mice were subjected to a myeloablative whole body irradiation dose of 8 Gy and subsequent BM-Tx and compared with age- and sex-matched untreated controls. AE2 cell changes were investigated quantitatively by design-based stereology. Compared with WT, untreated SP-D -/- mice showed a higher number of larger sized AE2 cells and a greater amount of surfactant-storing lamellar bodies. Irradiation and BM-Tx induced hyperplasia and hypertrophy in WT and SP-D -/- mice as well as the formation of giant lamellar bodies. The experimentally induced alterations were more severe in the SP-D -/- than in the WT mice, particularly with respect to the surfactant-storing lamellar bodies which were sometimes extremely enlarged in SP-D -/- mice. In conclusion, irradiation and BM-Tx have profound long-term effects on AE2 cells and their lamellar bodies. These data may explain some of the clinical pulmonary consequences of this procedure. The data should also be taken into account when BM-Tx is used as an experimental procedure to investigate the impact of bone marrow-derived cells for the phenotype of a specific genotype in the mouse.

  14. Absorption-enhancing effects of gemini surfactant on the intestinal absorption of poorly absorbed hydrophilic drugs including peptide and protein drugs in rats.

    Science.gov (United States)

    Alama, Tammam; Kusamori, Kosuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

    2016-02-29

    In general, the intestinal absorption of small hydrophilic molecules and macromolecules like peptides, after oral administration is very poor. Absorption enhancers are considered to be one of the most promising agents to enhance the intestinal absorption of drugs. In this research, we focused on a gemini surfactant, a new type of absorption enhancer. The intestinal absorption of drugs, with or without sodium dilauramidoglutamide lysine (SLG-30), a gemini surfactant, was examined by an in situ closed-loop method in rats. The intestinal absorption of 5(6)-carboxyfluorescein (CF) and fluorescein isothiocyanate-dextrans (FDs) was significantly enhanced in the presence of SLG-30, such effect being reversible. Furthermore, the calcium levels in the plasma significantly decreased when calcitonin was co-administered with SLG-30, suggestive of the increased intestinal absorption of calcitonin. In addition, no significant increase in the of lactate dehydrogenase (LDH) activity or in protein release from the intestinal epithelium was observed in the presence of SLG-30, suggestive of the safety of this compound. These findings indicate that SLG-30 is an effective absorption-enhancer for improving the intestinal absorption of poorly absorbed drugs, without causing serious damage to the intestinal epithelium. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Colloid and surfactant

    International Nuclear Information System (INIS)

    Kuk, Yun Hwan; Lee, Jeong Jung; Cho, Sun Chae; Ryeo, Su Dong

    1995-08-01

    This book consists of two parts about colloid and surfactant. The first parts has explanations colloid and surface science, which deal with creation and properties of colloidal particles, surfactant and micelle colloid, property of surfactant, membranes, absorption of surface science, electrokinetic phenomenon, emulsion, foam and rheology. The second part mentions surfactant on anionic surfactant with five types, amphoteric surface active agent, non-ionic surface active agent and use of surfactant.

  16. Circadian rhythm and the influence of physical activity on circulating surfactant protein D in early and long-standing rheumatoid arthritis

    DEFF Research Database (Denmark)

    Christensen, A F; Hoegh, S V; Lottenburger, T

    2011-01-01

    Surfactant protein D (SP-D) belongs to the collectin family and has pro-and anti-inflammatory capacities depending on its oligomerization. Previously, circulating SP-D was shown to be decreased in early rheumatoid arthritis (RA) and negatively correlated to disease activity. This study aimed...... at assessing the diurnal rhythmicity and the influence of physical activity on circulating SP-D in patients with RA at different stages compared with healthy individuals. Patients with early RA (ERA) with disease duration ... in two sub-studies. Healthy individuals served as controls. Diurnal variation: blood samples were collected every 3 h from 7 a.m to 10 p.m and the following morning. Physical activity: blood sampling was done before and after standardized physical challenge. SP-D was measured by ELISA. SP-D exhibited...

  17. Experimental evidence of polymorphysm of sexual development in Capitella sp. B (Polychaeta: Capitellidae from Barcelona, Spain

    Directory of Open Access Journals (Sweden)

    Nuria Méndez

    2002-06-01

    Full Text Available The development and growth of Capitella sp. B obtained from Barcelona were studied under culture conditions. Trochophore and metatrochophore larvae hatched non-simultaneously (two release periods from single brood tubes. This is the first laboratory evidence of polymorphysm of sexual development in the Capitella capitata species-complex. During the first release period, only free swimming trochophores hatched. The females, still bearing larvae inside the brood tube, were transferred to another dish. After three days, ciliated metatrochophores hatched from 8.7% of the transferred broods. In a culture experiment, larvae maintained in sediment enriched with artificial food grew to immature and mature adults. In this condition, the larvae that hatched during the first release reached the immature adult stage, while the larvae derived from the second release became mature adults. Oogenesis was observed three times in one female from the second release, though no spawning and fertilization occurred under incubation with sib mature males. Two different sizes of coelomic oocytes were observed. Polymorphysm of sexual development is discussed as an advantageous reproductive strategy enhancing survival in organic enriched sediments.

  18. Crystallization and preliminary X-ray studies of azoreductases from Bacillus sp. B29

    International Nuclear Information System (INIS)

    Ogata, Daiki; Ooi, Toshihiko; Fujiwara, Takaaki; Taguchi, Seiichi; Tanaka, Isao; Yao, Min

    2010-01-01

    In order to determine the structure–function relationship of the azo-dye reduction mechanism, an X-ray crystallographic study of azoreductases was performed. Selenomethionine-labelled AzrA (SeMet-AzrA) and AzrC were crystallized by the hanging-drop vapour-diffusion method. Azoreductases from Bacillus sp. B29 are NADH-dependent flavoenzymes which contain a flavin mononucleotide (FMN) as a prosthetic group and exist as homodimers composed of 23 kDa subunits. These enzymes catalyze the reductive degradation of various azo compounds by a ping-pong mechanism. In order to determine the structure–function relationship of the azo-dye reduction mechanism, an X-ray crystallographic study of azoreductases was performed. Selenomethionine-labelled AzrA (SeMet-AzrA) and AzrC were crystallized by the hanging-drop vapour-diffusion method. A crystal of SeMet-AzrA diffracted to 2.0 Å resolution and was determined to belong to space group P2 1 2 1 2 1 , with unit-cell parameters a = 56.9, b = 69.0, c = 105.4 Å. The native crystals of AzrC belonged to space group C2, with unit-cell parameters a = 192.0, b = 56.6, c = 105.5 Å, β = 115.7°, and diffracted to 2.21 Å resolution

  19. Surfactant proteins A, B, C and D in the human nasal airway: associated with mucosal glands and ciliated epithelium but absent in fluid-phase secretions and mucus.

    Science.gov (United States)

    Gaunsbaek, Maria Q; Kjeldsen, Anette D; Svane-Knudsen, Viggo; Henriksen, Maiken L; Hansen, Soren

    2014-01-01

    To investigate the presence of surfactant protein (SP) A, B, C and D in nasal airways and to determine whether the proteins exert their main functions in nasal secretions or in the deeper layers of the nasal mucosa. Volunteers were recruited from the Department of ENT Head and Neck Surgery, Odense University Hospital, Denmark. The study included 39 subjects. Nasal mucosal biopsies were analyzed by immunohistochemistry, and bronchoalveolar and nasal lavages, nasal brush biopsies and nasal mucus were analyzed for SP-A, -B, -C and -D by SDS-PAGE and Western blotting. The presence of SP-A and SP-D in the first three samplings were also analyzed by enzyme-linked immunosorbent assay. In nasal mucosal biopsies, SP-A, -B, -C and -D were all demonstrated in the serous acini of the submucosal glands and in the surface epithelium. SP-D was detected in nasal brush biopsies, whereas the other SPs were absent. Moreover, SP-A, -B, -C and -D were absent in nasal lavage and mucus. SP-A, -B, -C and -D exert their protective effect in the ductal epithelium of the submucosal glands rather than in nasal secretions and mucus. Further studies are required to clarify the functions of these proteins in nasal secretory pathways for understanding upper airway diseases. © 2014 S. Karger AG, Basel.

  20. Impact of Azospirillum sp. B510 inoculation on rice-associated bacterial communities in a paddy field.

    Science.gov (United States)

    Bao, Zhihua; Sasaki, Kazuhiro; Okubo, Takashi; Ikeda, Seishi; Anda, Mizue; Hanzawa, Eiko; Kakizaki, Kaori; Sato, Tadashi; Mitsui, Hisayuki; Minamisawa, Kiwamu

    2013-01-01

    Rice seedlings were inoculated with Azospirillum sp. B510 and transplanted into a paddy field. Growth in terms of tiller numbers and shoot length was significantly increased by inoculation. Principal-coordinates analysis of rice bacterial communities using the 16S rRNA gene showed no overall change from B510 inoculation. However, the abundance of Veillonellaceae and Aurantimonas significantly increased in the base and shoots, respectively, of B510-inoculated plants. The abundance of Azospirillum did not differ between B510-inoculated and uninoculated plants (0.02-0.50%). These results indicate that the application of Azospirillum sp. B510 not only enhanced rice growth, but also affected minor rice-associated bacteria.

  1. Site-directed mutagenesis of surfactant protein A reveals dissociation of lipid aggregation and lipid uptake by alveolar type II cells.

    Science.gov (United States)

    Tsunezawa, W; Sano, H; Sohma, H; McCormack, F X; Voelker, D R; Kuroki, Y

    1998-09-08

    Surfactant protein A (SP-A) binds to dipalmitoylphosphatidylcholine (DPPC) and induces phospholipid vesicle aggregation. It also regulates the uptake and secretion of surfactant lipids by alveolar type II cells. We introduced the single mutations Glu195-->Gln (rE195Q), Lys201-->Ala (rK201A) and Lys203-->Ala (rK203A) for rat SP-A, Arg199-->Ala (hR199A) and Lys201-->Ala (hK201A) for human SP-A, and the triple mutations Arg197, Lys201 and Lys203-->Ala (rR197A/K201A/K203A) for rat SP-A, into cDNAs for SP-A, and expressed the recombinant proteins using baculovirus vectors. All recombinant proteins avidly bound to DPPC liposomes. rE195Q, rK201A, rK203A, hR199A and hK201A function with activity comparable to wild type SP-A. Although rR197A/K201A/K203A was a potent inducer of phospholipid vesicle aggregation, it failed to stimulate lipid uptake. rR197A/K201A/K203A was a weak inhibitor for lipid secretion and did not competed with rat [125I]SP-A for receptor occupancy. From these results, we conclude that Lys201 and Lys203 of rat SP-A, and Arg199 and Lys201 of human SP-A are not individually critical for the interaction with lipids and type II cells, and that Glu195 of rat SP-A can be replaced with Gln without loss of SP-A functions. This study also demonstrates that the SP-A-mediated lipid uptake is not directly correlated with phospholipid vesicle aggregation, and that specific interactions of SP-A with type II cells are involved in the lipid uptake process.

  2. Thermally cleavable surfactants

    Science.gov (United States)

    McElhanon, James R [Manteca, CA; Simmons, Blake A [San Francisco, CA; Zifer, Thomas [Manteca, CA; Jamison, Gregory M [Albuquerque, NM; Loy, Douglas A [Albuquerque, NM; Rahimian, Kamyar [Albuquerque, NM; Long, Timothy M [Urbana, IL; Wheeler, David R [Albuquerque, NM; Staiger, Chad L [Albuquerque, NM

    2006-04-04

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments and the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  3. Thermally cleavable surfactants

    Science.gov (United States)

    McElhanon, James R [Manteca, CA; Simmons, Blake A [San Francisco, CA; Zifer, Thomas [Manteca, CA; Jamison, Gregory M [Albuquerque, NM; Loy, Douglas A [Albuquerque, NM; Rahimian, Kamyar [Albuquerque, NM; Long, Timothy M [Urbana, IL; Wheeler, David R [Albuquerque, NM; Staiger, Chad L [Albuquerque, NM

    2009-11-24

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments or the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  4. Changes in blood monocyte Toll-like receptor and serum surfactant protein A reveal a pathophysiological mechanism for community-acquired pneumonia in patients with type 2 diabetes.

    Science.gov (United States)

    Que, Y; Shen, X

    2016-02-01

    The lung is one of the target organs of microangiopathy in diabetes mellitus (DM); patients with type 2 diabetes mellitus (T2DM) are vulnerable to pneumonia, and a variety of pathophysiological mechanisms has been described. This study aimed to determine the pathophysiological mechanism of community-acquired pneumonia (CAP) in T2DM patients. A total of 90 individuals was included in this study comprised of three groups (n = 30): healthy control, T2DM and T2DM+ CAP groups. Toll-like receptor (TLR)2 and 4 protein and messenger RNA expression in peripheral blood monocytes(PBMC) was assessed by western blot and reverse transcription-polymerase chain reaction, respectively, and surfactant protein A (SP-A) levels were examined in serum samples by enzyme-linked immunosorbent assay. In T2DM and T2DM+CAP groups, levels of both TLR2/4 protein and mRNA in PBMC were decreased compared with controls (P <0.05), with lower levels observed in the T2DM+CAP group in comparison with T2DM patients (P <0.05). The serum SP-A levels in T2DM+CAP individuals were significantly higher than the values obtained for T2DM patients (P <0.05). It also showed apparent increases when compared with that in controls although no statistical significance was detected. In T2DM patients with pneumonia, TLR2/4 levels in PBMC and serum SP-A were altered, maybe playing an important role in the susceptibility to pneumonia in T2DM patients. © 2016 Royal Australasian College of Physicians.

  5. Abnormal SDS-PAGE migration of cytosolic proteins can identify domains and mechanisms that control surfactant binding

    Science.gov (United States)

    Shi, Yunhua; Mowery, Richard A; Ashley, Jonathan; Hentz, Michelle; Ramirez, Alejandro J; Bilgicer, Basar; Slunt-Brown, Hilda; Borchelt, David R; Shaw, Bryan F

    2012-01-01

    The amino acid substitution or post-translational modification of a cytosolic protein can cause unpredictable changes to its electrophoretic mobility during SDS-PAGE. This type of “gel shifting” has perplexed biochemists and biologists for decades. We identify a mechanism for “gel shifting” that predominates among a set of ALS (amyotrophic lateral sclerosis) mutant hSOD1 (superoxide dismutase) proteins, post-translationally modified hSOD1 proteins, and homologous SOD1 proteins from different organisms. By first comparing how 39 amino acid substitutions throughout hSOD1 affected SDS-PAGE migration, we found that substitutions that caused gel shifting occurred within a single polyacidic domain (residues ∼80–101), and were nonisoelectric. Substitutions that decreased the net negative charge of domain 80–101 increased migration; only one substitution increased net negative charge and slowed migration. Capillary electrophoresis, circular dichroism, and size exclusion chromatography demonstrated that amino acid substitutions increase migration during SDS-PAGE by promoting the binding of three to four additional SDS molecules, without significantly altering the secondary structure or Stokes radius of hSOD1-SDS complexes. The high negative charge of domain 80–101 is required for SOD1 gel shifting: neutralizing the polyacidic domain (via chimeric mouse-human SOD1 fusion proteins) inhibited amino acid substitutions from causing gel shifting. These results demonstrate that the pattern of gel shifting for mutant cytosolic proteins can be used to: (i) identify domains in the primary structure that control interactions between denatured cytosolic proteins and SDS and (ii) identify a predominant chemical mechanism for the interaction (e.g., hydrophobic vs. electrostatic). PMID:22692797

  6. Innate Immune Molecule Surfactant Protein D Attenuates Sepsis-induced Acute Pancreatic Injury through Modulating Apoptosis and NF-κB-mediated Inflammation.

    Science.gov (United States)

    Liu, Zhiyong; Shi, Qiao; Liu, Jiao; Abdel-Razek, Osama; Xu, Yongan; Cooney, Robert N; Wang, Guirong

    2015-12-04

    Sepsis causes multiple-organ dysfunction including pancreatic injury, thus resulting in high mortality. Innate immune molecule surfactant protein D (SP-D) plays a critical role in host defense and regulating inflammation of infectious diseases. In this study we investigated SP-D functions in the acute pancreatic injury (API) with C57BL/6 Wild-type (WT) and SP-D knockout (KO) mice in cecal ligation and puncture (CLP) model. Our results confirm SP-D expression in pancreatic islets and intercalated ducts and are the first to explore the role of pancreatic SP-D in sepsis. CLP decreased pancreatic SP-D levels and caused severe pancreatic injury with higher serum amylase 24 h after CLP. Apoptosis and neutrophil infiltration were increased in the pancreas of septic KO mice (p < 0.05, vs septic WT mice), with lower Bcl-2 and higher caspase-3 levels in septic KO mice (p < 0.05). Molecular analysis revealed increased NF-κB-p65 and phosphorylated IκB-α levels along with higher serum levels of TNF-α and IL-6 in septic KO mice compared to septic WT mice (p < 0.01). Furthermore, in vitro islet cultures stimulated with LPS produced higher TNF-α and IL-6 (p < 0.05) from KO mice compared to WT mice. Collectively, these results demonstrate SP-D plays protective roles by inhibiting apoptosis and modulating NF-κB-mediated inflammation in CLP-induced API.

  7. Gemini (dimeric) Surfactants

    Indian Academy of Sciences (India)

    Gemini, surfactants, micelle. Figure 1. Schematic repre- sentation of the gemini sur- factant structure. B S Sekhon. A gemini surfactant (GS) consists of two conventional surfactant molecules chemically bonded together by a spacer. The two terminal hydrocarbon tails can be short or long; the two polar head groups can be ...

  8. Comparative study of the effects of PM1-induced oxidative stress on autophagy and surfactant protein B and C expressions in lung alveolar type II epithelial MLE-12 cells.

    Science.gov (United States)

    Bai, Ru; Guan, Longfei; Zhang, Wei; Xu, Jinxia; Rui, Wei; Zhang, Fang; Ding, Wenjun

    2016-12-01

    There is a strong link between smaller air pollution particles and a range of serious health conditions. Thus, there is a need for understanding the impacts of airborne fine particulate matter (PM) with an aerodynamic diameter of PM1) on lung alveolar epithelial cells. In the present study, mouse lung epithelial type II cell MLE-12 cells were used to examine the intracellular oxidative responses and the surfactant protein expressions after exposure to various concentrations of PM1 collected from an urban site and a steel-factory site (referred as uPM1 and sPM1 hereafter, respectively). Physicochemical characterization of PM1 was performed by using scanning electron microscopy and transmission electron microscopy. Cytotoxicity and autophagy induced by PM1 were assessed by using comprehensive approaches after MLE-12 cells were exposed to different concentrations of PM1 for various times. Expression of surfactant proteins B and C in MLE-12 cells was determined by Western blotting. All of the tested PM1 induced cytotoxicity evidenced by significant decrease of cell viability and increase of lactate dehydrogenase (LDH) release in a time- and concentration-dependent manner in the exposed cells compared with the unexposed cells. A similar pattern of increase of intercellular reactive oxygen species (ROS) generation and decrease of superoxide dismutase (SOD) and catalase (CAT) activities was also observed. PM1-induced autophagy was evidenced by an increase in microtubule-associated protein light chain-3 (LC3) puncta, accumulation of LC3II, and increased levels of beclin1. Data from Western blotting showed significant decrease of surfactant protein B and C expressions. Relatively high concentrations of transition metals, including Fe, Cu and Mn, may be responsible for the higher toxicity of sPM1 compared with uPM1. Moreover, pretreatment with N-acetylcysteine (NAC) or Chelex (a metal chelating agent, which removes a large suite of metals from PM1) prevented the increase of

  9. Addition of Surfactants and Non-Hydrolytic Proteins and Their Influence on Enzymatic Hydrolysis of Pretreated Sugarcane Bagasse.

    Science.gov (United States)

    Méndez Arias, Johanna; de Oliveira Moraes, Anelize; Modesto, Luiz Felipe Amarante; de Castro, Aline Machado; Pereira, Nei

    2017-02-01

    Poly(ethylene glycol) (PEG 4000) and bovine serum albumin (BSA) were investigated with the purpose of evaluating their influence on enzymatic hydrolysis of sugarcane bagasse. Effects of these supplements were assayed for different enzymatic cocktails (Trichoderma harzianum and Penicillium funiculosum) that acted on lignocellulosic material submitted to different pretreatment methods with varying solid (25 and 100 g/L) and protein (7.5 and 20 mg/g cellulose) loadings. The highest levels of glucose release were achieved using partially delignified cellulignin as substrate, along with the T. harzianum cocktail: increases of 14 and 18 % for 25 g/L solid loadings and of 33 and 43 % for 100 g/L solid loadings were reached for BSA and PEG supplementation, respectively. Addition of these supplements could maintain hydrolysis yield even for higher solid loadings, but for higher enzymatic cocktail protein loadings, increases in glucose release were not observed. Results indicate that synergism might occur among these additives and cellulase and xylanases. The use of these supplements, besides depending on factors such as pretreatment method of sugarcane bagasse, enzymatic cocktails composition, and solid and protein loadings, may not always lead to positive effects on the hydrolysis of lignocellulosic material, making it necessary further statistical studies, according to process conditions.

  10. Intrinsic structural differences in the N-terminal segment of pulmonary surfactant protein SP-C from different species

    DEFF Research Database (Denmark)

    Plasencia, I; Rivas, L; Casals, C

    2001-01-01

    is that intrinsic structural determinants of the sequence of the N-terminal region of SP-C could define conformation, acylation and perhaps surface properties of the mature protein. To test this hypothesis we have synthesized peptides corresponding to the 13-residue N-terminal sequence of porcine and canine SP...... the packing of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG) monolayers, the effects being always higher in anionic than in zwitterionic lipids, and also substantially higher in films containing canine peptide in comparison to porcine peptide. Acylation of cysteines at the N...

  11. SP-A-enriched surfactant for treatment of rat lung transplants with SP-A deficiency after storage and reperfusion

    NARCIS (Netherlands)

    Erasmus, ME; Hofstede, GJH; Petersen, AH; Batenburg, JJ; Haagsman, HP; Oetomo, SB; Prop, J

    2002-01-01

    Background. The function of pulmonary surfactant is affected by lung transplantation, contributing to impaired lung transplant function. A decreased amount of surfactant protein-A (SP-A) after reperfusion is believed to contribute to the impaired surfactant function. Surfactant treatment has been

  12. How to overcome surfactant dysfunction in meconium aspiration syndrome?

    Science.gov (United States)

    Mokra, Daniela; Calkovska, Andrea

    2013-06-01

    Surfactant dysfunction in meconium aspiration syndrome (MAS) is caused by meconium components, by plasma proteins leaking through the injured alveolocapillary membrane and by substances originated in meconium-induced inflammation. Surfactant inactivation in MAS may be diminished by several ways. Firstly, aspirated meconium should be removed from the lungs to decrease concentrations of meconium inhibitors coming into the contact with surfactant in the alveolar compartment. Once the endogenous surfactant becomes inactivated, components of surfactant should be substituted by exogenous surfactant at a sufficient dose, and surfactant administration should be repeated, if oxygenation remains compromised. To delay the inactivation by inhibitors, exogenous surfactants may be enriched with surfactant proteins, phospholipids, or other substances such as polymers. Finally, to diminish an adverse action of products of meconium-induced inflammation on both endogenous and exogenously delivered surfactant, anti-inflammatory drugs may be administered. A combined therapeutic approach may result in better outcome in patients with MAS and in lower costs of treatment. Copyright © 2013. Published by Elsevier B.V.

  13. Surfactant protein D inhibits adherence of uropathogenic Escherichia coli to the bladder epithelial cells and the bacterium-induced cytotoxicity: a possible function in urinary tract.

    Science.gov (United States)

    Kurimura, Yuichiro; Nishitani, Chiaki; Ariki, Shigeru; Saito, Atsushi; Hasegawa, Yoshihiro; Takahashi, Motoko; Hashimoto, Jiro; Takahashi, Satoshi; Tsukamoto, Taiji; Kuroki, Yoshio

    2012-11-16

    The adherence of uropathogenic Escherichia coli (UPEC) to the host urothelial surface is the first step for establishing UPEC infection. Uroplakin Ia (UPIa), a glycoprotein expressed on bladder urothelium, serves as a receptor for FimH, a lectin located at bacterial pili, and their interaction initiates UPEC infection. Surfactant protein D (SP-D) is known to be expressed on mucosal surfaces in various tissues besides the lung. However, the functions of SP-D in the non-pulmonary tissues are poorly understood. The purposes of this study were to investigate the possible function of SP-D expressed in the bladder urothelium and the mechanisms by which SP-D functions. SP-D was expressed in human bladder mucosa, and its mRNA was increased in the bladder of the UPEC infection model in mice. SP-D directly bound to UPEC and strongly agglutinated them in a Ca(2+)-dependent manner. Co-incubation of SP-D with UPEC decreased the bacterial adherence to 5637 cells, the human bladder cell line, and the UPEC-induced cytotoxicity. In addition, preincubation of SP-D with 5637 cells resulted in the decreased adherence of UPEC to the cells and in a reduced number of cells injured by UPEC. SP-D directly bound to UPIa and competed with FimH for UPIa binding. Consistent with the in vitro data, the exogenous administration of SP-D inhibited UPEC adherence to the bladder and dampened UPEC-induced inflammation in mice. These results support the conclusion that SP-D can protect the bladder urothelium against UPEC infection and suggest a possible function of SP-D in urinary tract.

  14. Altered expression of cyclooxygenase-2, 12-lipoxygenase, inducible nitric oxide synthase-2 and surfactant protein D in lungs of patients with pulmonary injury caused by sulfur mustard.

    Science.gov (United States)

    Tahmasbpour, Eisa; Ghanei, Mostafa; Khor, Abolfazl; Panahi, Yunes

    2018-03-14

    Sulfur mustard (SM) is a strong alkylating toxicant that targets different organs, particularly human lung tissue. Change in genes expression is one of the molecular mechanisms of SM toxicity in damaged tissue. The purpose of this investigation is to characterize the expression of cyclooxygenase-2 (COX-2), 12-lipoxygenase (12-LO), inducible nitric oxide synthase 2 (iNOS2), and surfactant protein D (SFTPD) in lungs of patients who exposed to SM. Lung biopsies were provided from SM-exposed patients (n = 6) and controls (n = 5). Total RNA were extracted from all specimens and then cDNA was synthesized for each sample. Changes in gene expression were measured using RT 2 Profiler ™PCR Array. Pulmonary function tests revealed more obstructive and restrictive spirometric patterns among patients compared to the control group. Expression of COX-2 and 12-LO in the lung of patients was increased by 6.2555 (p = 0.004) and 6.2379-folds (p = 0.002), respectively. In contrast, expression of SF-D and iNOS genes was reduced by 8.5869-fold (p = 0.005) and 2.4466-folds (p = 0.011), respectively. Mustard lungs were associated with overexpression of COX-2 and 12-LO, which are responsible for inflammation, overproduction of free radicals and oxidative stress. Downregulation of iNOS2 and SF-D are probably the reason for lung disease and dysfunction among these patients. Therefore, the expression of these genes could be an important, routine part of the management of such patients.

  15. Surfactant protein A (SP-A) and angiotensin converting enzyme (ACE) as early biomarkers for pulmonary edema formation in ventilated human lung lobes.

    Science.gov (United States)

    Gnadt, Mirjam; Kardziev, Boris; Schmidt, Michael; Högger, Petra

    2012-08-01

    Ex vivo perfused and ventilated lung lobes frequently develop pulmonary edema. We were looking for a suitable and early detectable biomarker in the perfusion fluid indicating lung cell damage and loss of tissue integrity in ventilated human lung lobes. Therefore, we elucidated whether surfactant protein A (SP-A) and angiotensin-converting enzyme (ACE) were measurable in the perfusion fluid and whether they were suitable indicators for edema formation occurring within the experimental time frame of 1-2 h. Patients (n = 39) undergoing a lobectomy, bilobectomy or pneumonectomy due to primary bronchial cell carcinoma were included in the studies. Lung lobes were extracorporally ventilated and perfused for up to 2 h. Two different perfusion fluids were used, plain perfusion buffer and perfusion buffer containing packed erythrocytes or buffy coats. Perfusion fluid samples were analyzed for SP-A and ACE using immunoassays served as perfusion fluids. SP-A and ACE concentrations were analyzed in fluid sample sets of 39 and 33 perfusion experiments, respectively. Degrees of edema formation were arbitrarily classified into three groups (≤ 29, 30-59, ≥ 60 % weight gain). The maximum increase of SP-A and ACE concentrations in the perfusate was significantly higher for more pronounced edemas in case of perfusions using a mixture of blood components and buffer. Interestingly, the time courses of ACE and SP-A were highly similar. We suggest that SP-A and ACE are promising early biochemical markers for the development for pulmonary edema formation in the ex vivo lung lobe perfusion.

  16. Cloning and characterization of the novel D-aspartyl endopeptidase, paenidase, from Paenibacillus sp. B38.

    Science.gov (United States)

    Nirasawa, Satoru; Nakahara, Kazuhiko; Takahashi, Saori

    2018-02-27

    Paenidase is the first microorganism-derived D-aspartyl endopeptidase that specifically recognizes an internal D-Asp residue to cleave [D-Asp]-X peptide bonds. Using peptide sequences obtained from the protein, we performed PCR with degenerate primers to amplify the paenidase I-encoding gene. Nucleotide sequencing revealed that mature paenidase I consists of 322 amino acid residues and that the protein is encoded as a pro-protein with a 197-amino-acid N-terminal extension compared to the mature protein. Paenidase I exhibits amino acid sequence similarity to several penicillin-binding proteins. In addition, paenidase I was classified into peptidase family S12 based on a MEROPS database search. Family S12 contains serine-type D-Ala-D-Ala carboxypeptidases that have three active site residues (Ser, Lys, and Tyr) in the conserved motifs Ser-Xaa-Thr-Lys and Tyr-Xaa-Asn. These motifs were conserved in the primary structure of paenidase I, and the role of these residues was confirmed by site-directed mutagenesis.

  17. Surfactants in tribology

    CERN Document Server

    Biresaw, Girma

    2014-01-01

    Surface science and tribology play very critical roles in many industries. Manufacture and use of almost all consumer and industrial products rely on the application of advanced surface and tribological knowledge. The fourth in a series, Surfactants in Tribology, Volume 4 provides an update on research and development activities connecting surfactants and tribological phenomena. Written by renowned subject matter experts, the book demonstrates how improved design of surfactants can be harnessed to control tribological phenomena. Profusely illustrated and copiously referenced, the chapters also

  18. Surfactant Proteins-A and -D Attenuate LPS-Induced Apoptosis in Primary Intestinal Epithelial Cells (IECs).

    Science.gov (United States)

    Zhang, Linlin; Meng, Qinghe; Yepuri, Natesh; Wang, Guirong; Xi, Xiuming; Cooney, Robert N

    2018-01-01

    SP-A/D KO mice with sepsis demonstrate more severe lung, kidney, and gut injury/apoptosis than WT controls. We hypothesize SP-A and SP-D directly regulate lipopolysaccharide (LPS)-induced P38 mitogen-activated protein kinase (MAPK) activation and gut apoptosis during sepsis. Primary IECs were established from SP-A/D KO or C57BL/6 WT mice, stimulated with LPS and harvested at 24 h. IECs from WT mice were treated with SP-A, SP-D, or vehicle for 20 h, then LPS for 24 h. Apoptosis, cleaved caspase-3 levels and the ratio of BAX/Bcl-2 were assayed. The role of P38 MAPK was examined using the P38 MAPK-agonist U46619 and inhibitor SB203580 in LPS-treated cells. p-P38 MAPK/t-P38 MAPK, TLR4, and CD14 were measured by Western Blot. LPS-induced apoptosis, caspase-3 levels, BAX/Bcl-2, and p-P38/t-P38 MAPK were increased in SP-A/D KO IECs. SP-A and SP-D attenuate LPS-induced increase in apoptosis, cleaved caspase-3, BAX/Bcl-2, and p-P38/t-P38 MAPK in WT IECs. U46619 increased apoptosis, caspase-3, and BAX/Bcl-2 in IECs which was attenuated by SP-A/D. SB203580 attenuates the LPS-induced increase in apoptosis, caspase-3, and BAX/Bcl-2 in WT IECs. Addition of SP-A or SP-D to SB203580 completely ameliorates LPS-induced apoptosis. The LPS-induced increase in TLR4 and CD14 expression is greater in IECs from SP-A/D KO mice and treatment of WT IECs with SP-A or SP-D prevents the LPS-induced increase in TLR4 and CD14. SP-A and SP-D attenuate LPS-induced increases in apoptosis, caspase-3, and BAX/Bcl-2 in IECs. Attenuation of LPS-induced activation of TLR4 and P38 MAPK signaling pathways represents potential mechanisms for the protective effects of SP-A/D on apoptosis.

  19. Genetics Home Reference: surfactant dysfunction

    Science.gov (United States)

    ... Email Facebook Twitter Home Health Conditions Surfactant dysfunction Surfactant dysfunction Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Surfactant dysfunction is a lung disorder that causes breathing ...

  20. Biodegradation of alpha and beta endosulfan in broth medium and soil microcosm by bacterial strain Bordetella sp. B9.

    Science.gov (United States)

    Goswami, Supriya; Singh, Dileep K

    2009-04-01

    Bacterial strains were isolated from endosulfan treated soil to study the microbial degradation of this pesticide in broth medium and soil microcosm. The isolates were grown in minimal medium and screened for endosulfan degradation. The strain, which utilized endosulfan and showed maximum growth, was selected for detail studies. Maximum degrading capability in shake flask culture was shown by Bordetella sp. B9 which degraded 80% of alpha endosulfan and 86% of beta endosulfan in 18 days. Soil microcosm study was also carried out using this strain in six different treatments. Endosulfan ether and endosulfan lactone were the main metabolites in broth culture, while in soil microcosm endosulfan sulfate was also found along with endosulfan ether and endosulfan lactone. This bacterial strain has a potential to be used for bioremediation of the contaminated sites.

  1. Salivary agglutinin and lung scavenger receptor cysteine-rich glycoprotein 340 have broad anti-influenza activities and interactions with surfactant protein D that vary according to donor source and sialylation

    DEFF Research Database (Denmark)

    Hartshorn, Kevan L.; Ligtenberg, Antoon; White, Mitchell R.

    2006-01-01

    from this donor as compared with salivary gp-340 from another donor or several preparations of lung gp-340. Hence, the specificity of sialic acid linkages on gp-340 is an important determinant of anti-IAV activity. Gp-340 binds to SP-D (surfactant protein D), and we previously showed that lung gp-340...... has co-operative interactions with SP-D in viral neutralization and aggregation assays. We now report that salivary gp-340 can, in some cases, strongly antagonize certain antiviral activities of SP-D. This effect was associated with greater binding of salivary gp-340 to the carbohydrate recognition...

  2. Pulmonary infections in swine induce altered porcine surfactant protein D expression and localization to dendritic cells in bronchial-associated lymphoid tissue

    DEFF Research Database (Denmark)

    Sørensen, C.M.; Holmskov, U.; Aalbæk, B.

    2005-01-01

    pyogenes and Streptococcus suis serotype 2, respectively. By comparing normal and diseased lung tissue from the same lungs, increased diffuse pSP-D immunoreactivity was seen in the surfactant in both acute and chronic bronchopneumonias, while such increased expression of pSP-D was generally not present...

  3. Fundamentals of surfactant sputtering

    International Nuclear Information System (INIS)

    Hofsaess, Hans; Zhang Kun

    2009-01-01

    We introduce a new sputter technique, utilizing the steady-state coverage of a substrate surface with up to 10 16 cm -2 of foreign atoms simultaneously during sputter erosion by combined ion irradiation and atom deposition. These atoms strongly modify the substrate sputter yield on atomic to macroscopic length scales and therefore act as surfactant atoms (a blend of 'surface active agent'). Depending on the surfactant-substrate combination, the novel technique allows enhanced surface smoothing, generation of novel surface patterns, shaping of surfaces and formation of ultra-thin films. Sputter yield attenuation is demonstrated for sputtering of Si and Fe substrates and different surfactant species using 5 keV Xe ions at different incidence angles and fluences up to 10 17 cm -2 . Analytical approaches and Monte Carlo simulations are used to predict the sputtering yield attenuation as function of surfactant coverage. For sputtering of Si with Au surfactants we observe high sputter yields despite a steady-state surfactant coverage, which can be explained by strong ion-induced interdiffusion of substrate and surfactant atoms and the formation of a buried Au x Si surfactant layer in dynamic equilibrium.

  4. Dynamic covalent surfactants

    NARCIS (Netherlands)

    Minkenberg, C.B.

    2012-01-01

    In this thesis the development of surfactant aggregates with fast exchange dynamics between the aggregated and non-aggregated state is described. Dynamic surfactant exchange plays an important role in natural systems, for instance in cell signaling, cell division, and uptake and release of cargo.

  5. Surfactant protein-D predicts prognosis of interstitial lung disease induced by anticancer agents in advanced lung cancer: a case control study.

    Science.gov (United States)

    Nakamura, Kota; Kato, Motoyasu; Shukuya, Takehito; Mori, Keita; Sekimoto, Yasuhito; Ihara, Hiroaki; Kanemaru, Ryota; Ko, Ryo; Shibayama, Rina; Tajima, Ken; Koyama, Ryo; Shimada, Naoko; Nagashima, Osamu; Takahashi, Fumiyuki; Sasaki, Shinichi; Takahashi, Kazuhisa

    2017-05-02

    Interstitial lung diseases induced by anticancer agents (ILD-AA) are rare adverse effects of anticancer therapy. However, prognostic biomarkers for ILD-AA have not been identified in patients with advanced lung cancer. Our aim was to analyze the association between serum biomarkers sialylated carbohydrate antigen Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D), and clinical characteristics in patients diagnosed with ILD-AA. Between April 2011 and March 2016, 1224 advanced lung cancer patients received cytotoxic agents and epidermal growth factor receptor tyrosine kinase inhibitors at Juntendo University Hospital and Juntendo University Urayasu Hospital. Of these patients, those diagnosed with ILD-AA were enrolled in this case control study. ΔKL-6 and ΔSP-D were defined as the difference between the levels at the onset of ILD-AA and their respective levels prior to development of ILD-AA. We evaluated KL-6 and SP-D at the onset of ILD-AA, ΔKL-6 and ΔSP-D, the risk factors for death related to ILD-AA, the chest high resolution computed tomography (HRCT) findings, and survival time in patients diagnosed with ILD-AA. Thirty-six patients diagnosed with ILD-AA were enrolled in this study. Among them, 14 patients died of ILD-AA. ΔSP-D in the patients who died was significantly higher than that in the patients who survived. However, ΔKL-6 did not differ significantly between the two groups. Moreover, ΔSP-D in patients who exhibited diffuse alveolar damage was significantly higher than that in the other patterns on HRCT. Receiver operating characteristic curve analysis was used to set the optimal cut off value for ΔSP-D at 398 ng/mL. Survival time for patients with high ΔSP-D (≥ 398 ng/mL) was significantly shorter than that for patients with low ΔSP-D. Multivariate analysis revealed that ΔSP-D was a significant prognostic factor of ILD-AA. This is the first research to evaluate high ΔSP-D (≥ 398 ng/mL) in patients with ILD-AA and to

  6. Meconium-induced inflammation and surfactant inactivation: specifics of molecular mechanisms.

    Science.gov (United States)

    Kopincova, Jana; Calkovska, Andrea

    2016-04-01

    This review summarizes neonatal meconium aspiration syndrome in light of meconium-induced inflammation and inflammatory surfactant inactivation, related to both endogenous and therapeutic exogenous surfactant. The wide effect of meconium on surfactant properties is divided into three points. Direct effect of meconium on surfactant properties refers mainly to fragmentation of dipalmitoylphosphatidylcholine and other surfactant phospholipids together with cleavage of surfactant proteins. Initiation of inflammatory response due to activation of receptors by yet unspecified compounds involves complement and Toll-like receptor activation. A possible role of lung collectins, surfactant proteins A and D, which can exert both pro- and anti-inflammatory reactions, is discussed. Initiation of inflammatory response by specified compounds in meconium reflects inflammatory functioning of cytokines, bile acids, and phospholipases contained in meconium. Unifying sketch of many interconnections in all these actions aims at providing integrated picture of inflammatory surfactant inactivation.

  7. Surfactants in the environment.

    Science.gov (United States)

    Ivanković, Tomislav; Hrenović, Jasna

    2010-03-01

    Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products. After use, residual surfactants are discharged into sewage systems or directly into surface waters, and most of them end up dispersed in different environmental compartments such as soil, water or sediment. The toxic effects of surfactants on various aquatic organisms are well known. In general, surfactants are present in the environment at levels below toxicity and in Croatia below the national limit. Most surfactants are readily biodegradable and their amount is greatly reduced with secondary treatment in wastewater treatment plants. The highest concern is the release of untreated wastewater or wastewater that has undergone primary treatment alone. The discharge of wastewater polluted with massive quantities of surfactants could have serious effects on the ecosystem. Future studies of surfactant toxicities and biodegradation are necessary to withdraw highly toxic and non-biodegradable compounds from commercial use and replace them with more environmentally friendly ones.

  8. Evolution of surfactant therapy for respiratory distress syndrome: past, present, and future.

    Science.gov (United States)

    Sardesai, Smeeta; Biniwale, Manoj; Wertheimer, Fiona; Garingo, Arlene; Ramanathan, Rangasamy

    2017-01-01

    Respiratory distress syndrome (RDS) due to surfactant deficiency is the most common cause of respiratory failure in preterm infants. Tremendous progress has been made since the original description that surfactant deficiency is the major cause of RDS. Surfactant therapy has been extensively studied in preterm infants and has been shown to significantly decrease air leaks and neonatal and infant mortality. Synthetic and animal-derived surfactants from bovine as well as porcine origin have been evaluated in randomized controlled trials. Animal-derived surfactants generally result in faster weaning of respiratory support, shorter duration of invasive ventilation, and decreased mortality when compared to first- or second-generation of synthetic surfactants, but some of the second-generation synthetic surfactants are at least not inferior to the animal-derived surfactants. Using a higher initial dose of porcine derived surfactant may provide better outcomes when compared with using lower doses of bovine surfactants, likely, due to compositional difference and/or the dose. Third-generation synthetic surfactant containing peptide analogs of surfactant protein B and C are currently being studied. Less invasive intra-tracheal surfactant administration techniques in spontaneously breathing neonate receiving noninvasive ventilator support are also being evaluated. In the present era, prophylactic surfactant is not recommended as it may increase the risk of lung injury or death. In the future, surfactants may be used as vector to deliver steroids, or used in combination with molecules, such as, recombinant Club Cell Protein-10 (rhCC-10) to improve pulmonary outcomes. Also, noninvasive surfactant administration techniques, such as aerosolization or atomization of surfactant may play a greater role in the future.

  9. Metathesis depolymerizable surfactants

    Science.gov (United States)

    Jamison, Gregory M [Albuquerque, NM; Wheeler, David R [Albuquerque, NM; Loy, Douglas A [Tucson, AZ; Simmons, Blake A [San Francisco, CA; Long, Timothy M [Evanston, IL; McElhanon, James R [Manteca, CA; Rahimian, Kamyar [Albuquerque, NM; Staiger, Chad L [Albuquerque, NM

    2008-04-15

    A class of surfactant molecules whose structure includes regularly spaced unsaturation in the tail group and thus, can be readily decomposed by ring-closing metathesis, and particularly by the action of a transition metal catalyst, to form small molecule products. These small molecules are designed to have increased volatility and/or enhanced solubility as compared to the original surfactant molecule and are thus easily removed by solvent extraction or vacuum extraction at low temperature. By producing easily removable decomposition products, the surfactant molecules become particularly desirable as template structures for preparing meso- and microstructural materials with tailored properties.

  10. Phosphine oxide surfactants revisited.

    Science.gov (United States)

    Stubenrauch, Cosima; Preisig, Natalie; Laughlin, Robert G

    2016-04-01

    This review summarizes everything we currently know about the nonionic surfactants alkyl dimethyl (C(n)DMPO) and alkyl diethyl (C(n)DEPO) phosphine oxide (PO surfactants). The review starts with the synthesis and the general properties (Section 2) of these compounds and continues with their interfacial properties (Section 3) such as surface tension, surface rheology, interfacial tension and adsorption at solid surfaces. We discuss studies on thin liquid films and foams stabilized by PO surfactants (Section 4) as well as studies on their self-assembly into lyotropic liquid crystals and microemulsions, respectively (Section 5). We aim at encouraging colleagues from both academia and industry to take on board PO surfactants whenever possible and feasible because of their broad variety of excellent properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Surfactants and the Mechanics of Respiration

    Science.gov (United States)

    Jbaily, Abdulrahman; Szeri, Andrew J.

    2016-11-01

    Alveoli are small sacs found at the end of terminal bronchioles in human lungs with a mean diameter of 200 μm. A thin layer of fluid (hypophase) coats the inner face of an alveolus and is in contact with the air in the lungs. The thickness of this layer varies among alveoli, but is in the range of 0.1 to 0.5 μm for many portions of the alveolar network. The interfacial tension σ at the air-hypophase interface tends to favor collapse of the alveolus, and resists its expansion during inhalation. Type II alveolar cells synthesize and secrete a mixture of phospholipids and proteins called pulmonary surfactant. These surfactant molecules adsorb to the interface causing σ of water at body temperature is 70 mN/m and falls to an equilibrium value of 25 mN/m when surfactants are present. Also, in a dynamic sense, it is known that σ is reduced to near 0 during exhalation when the surfactant film compresses. In this work, the authors develop a mechanical and transport model of the alveolus to study the effect of surfactants on various aspects of respiration. The model is composed of three principal parts: (i) air movement into and out of the alveolus; (ii) a balance of linear momentum across the two-layered membrane of the alveolus (hypophase and elastic wall); and (iii) a pulmonary surfactant transport problem in the hypophase. The goal is to evaluate the influence of pulmonary surfactant on respiratory mechanics.

  12. Effects of anthropogenic surfactants on the conversion of marine dissolved organic carbon and microgels.

    Science.gov (United States)

    Shiu, Ruei-Feng; Lee, Chon-Lin

    2017-04-15

    The possible impact of three types of anthropogenic surfactants on the ability of marine dissolved organic carbon (DOC) to form self-assembled microgels was evaluated. The behavior of existing native microgels was also examined in the presence of surfactants. These results reveal that the release of surfactants even at low concentrations into the aquatic environment could effectively hinder the self-assembly of DOC polymers. The extent of the size reduction had the following order: anionic, cationic, and non-ionic. Furthermore, charged surfactants can disrupt existing native microgels, converting large assemblies into smaller particles. One possible mechanisms is that surfactants are able to enhance the stability of DOC polymers and disrupt aggregates due to their surface charges and protein-denaturing activities. These findings suggest that the ecological system is altered by anthropogenic surfactants, and provide useful information for ecological assessments of different types of surfactants and raise warnings about surfactant applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Surfactant uptake dynamics in mammalian cells elucidated with quantitative coherent anti-stokes Raman scattering microspectroscopy.

    Directory of Open Access Journals (Sweden)

    Masanari Okuno

    Full Text Available The mechanism of surfactant-induced cell lysis has been studied with quantitative coherent anti-Stokes Raman scattering (CARS microspectroscopy. The dynamics of surfactant molecules as well as intracellular biomolecules in living Chinese Hamster Lung (CHL cells has been examined for a low surfactant concentration (0.01 w%. By using an isotope labeled surfactant having CD bonds, surfactant uptake dynamics in living cells has been traced in detail. The simultaneous CARS imaging of the cell itself and the internalized surfactant has shown that the surfactant molecules is first accumulated inside a CHL cell followed by a sudden leak of cytosolic components such as proteins to the outside of the cell. This finding indicates that surfactant uptake occurs prior to the cell lysis, contrary to what has been believed: surface adsorption of surfactant molecules has been thought to occur first with subsequent disruption of cell membranes. Quantitative CARS microspectroscopy enables us to determine the molecular concentration of the surfactant molecules accumulated in a cell. We have also investigated the effect of a drug, nocodazole, on the surfactant uptake dynamics. As a result of the inhibition of tubulin polymerization by nocodazole, the surfactant uptake rate is significantly lowered. This fact suggests that intracellular membrane trafficking contributes to the surfactant uptake mechanism.

  14. Sulfonamide inhibition studies of the β-carbonic anhydrase from the newly discovered bacterium Enterobacter sp. B13.

    Science.gov (United States)

    Eminoğlu, Ayşenur; Vullo, Daniela; Aşık, Aycan; Çolak, Dilşat Nigar; Çanakçı, Sabriye; Beldüz, Ali Osman; Supuran, Claudiu T

    2016-04-01

    The genome of the newly identified bacterium Enterobacter sp. B13 encodes for a β-class carbonic anhydrases (CAs, EC 4.2.1.1), EspCA. This enzyme was recently cloned, and characterized kinetically by this group (J. Enzyme Inhib. Med. Chem. 2016, 31). Here we report an inhibition study with sulfonamides and sulfamates of this enzyme. The best EspCA inhibitors were some sulfanylated sulfonamides with elongated molecules, metanilamide, 4-aminoalkyl-benzenesulfonamides, acetazolamide, and deacetylated methazolamide (KIs in the range of 58.7-96.5nM). Clinically used agents such as methazolamide, ethoxzolamide, dorzolamide, brinzolamide, benzolamide, zonisamide, sulthiame, sulpiride, topiramate and valdecoxib were slightly less effective inhibitors (KIs in the range of 103-138nM). Saccharin, celecoxib, dichlorophenamide and many simple benzenesulfonamides were even less effective as EspCA inhibitors, with KIs in the range of 384-938nM. Identification of effective inhibitors of this bacterial enzyme may lead to pharmacological tools useful for understanding the physiological role(s) of the β-class CAs in bacterial pathogenicity/virulence. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Cloning, expression and biochemical characterization of a β-carbonic anhydrase from the soil bacterium Enterobacter sp. B13.

    Science.gov (United States)

    Eminoğlu, Ayşenur; Vullo, Daniela; Aşık, Aycan; Çolak, Dilşat Nigar; Supuran, Claudiu T; Çanakçı, Sabriye; Osman Beldüz, Ali

    2016-12-01

    A recombinant carbonic anhydrase (CA, EC 4.2.1.1) from the soil-dwelling bacterium Enterobacter sp. B13 was cloned and purified by Co(2+) affinity chromatography. Bioinformatic analysis showed that the new enzyme (denominated here B13-CA) belongs to the β-class CAs and to possess 95% homology with the ortholog enzyme from Escherichia coli encoded by the can gene, whereas its sequence homology with the other such enzyme from E. coli (encoded by the cynT gene) was of 33%. B13-CA was characterized kinetically as a catalyst for carbon dioxide hydration to bicarbonate and protons. The enzyme shows a significant catalytic activity, with the following kinetic parameters at 20 °C and pH of 8.3: kcat of 4.8 × 10(5) s(-1) and kcat/Km of 5.6 × 10(7) M(-1) × s(-1). This activity was potently inhibited by acetazolamide which showed a KI of 78.9 nM. Although only this compound was investigated for the moment as B13-CA inhibitor, further studies may reveal new classes of inhibitors/activators of this enzyme which may show biomedical or environmental applications, considering the posssible role of this enzyme in CaCO3 biomineralization processes.

  16. Application of peptide gemini surfactants as novel solubilization surfactants for photosystems I and II of cyanobacteria.

    Science.gov (United States)

    Koeda, Shuhei; Umezaki, Katsunari; Noji, Tomoyasu; Ikeda, Atsushi; Kawakami, Keisuke; Kondo, Masaharu; Yamamoto, Yasushi; Shen, Jian-Ren; Taga, Keijiro; Dewa, Takehisa; Ito, Shigeru; Nango, Mamoru; Tanaka, Toshiki; Mizuno, Toshihisa

    2013-09-17

    We designed novel peptide gemini surfactants (PG-surfactants), DKDKC12K and DKDKC12D, which can solubilize Photosystem I (PSI) of Thermosynecoccus elongatus and Photosystem II (PSII) of Thermosynecoccus vulcanus in an aqueous buffer solution. To assess the detailed effects of PG-surfactants on the original supramolecular membrane protein complexes and functions of PSI and PSII, we applied the surfactant exchange method to the isolated PSI and PSII. Spectroscopic properties, light-induced electron transfer activity, and dynamic light scattering measurements showed that PSI and PSII could be solubilized not only with retention of the original supramolecular protein complexes and functions but also without forming aggregates. Furthermore, measurement of the lifetime of light-induced charge-separation state in PSI revealed that both surfactants, especially DKDKC12D, displayed slight improvement against thermal denaturation below 60 °C compared with that using β-DDM. This degree of improvement in thermal resistance still seems low, implying that the peptide moieties did not interact directly with membrane protein surfaces. By conjugating an electron mediator such as methyl viologen (MV(2+)) to DKDKC12K (denoted MV-DKDKC12K), we obtained derivatives that can trap the generated reductive electrons from the light-irradiated PSI. After immobilization onto an indium tin oxide electrode, a cathodic photocurrent from the electrode to the PSI/MV-DKDKC12K conjugate was observed in response to the interval of light irradiation. These findings indicate that the PG-surfactants DKDKC12K and DKDKC12D provide not only a new class of solubilization surfactants but also insights into designing other derivatives that confer new functions on PSI and PSII.

  17. The use of solvent relaxation technique to investigate headgroup hydration and protein binding of simple and mixed phosphatidylcholine/surfactant bilayer membranes

    Czech Academy of Sciences Publication Activity Database

    Rieber, K.; Sýkora, Jan; Olžyńska, Agnieszka; Jelinek, R.; Cevc, G.; Hof, Martin

    2007-01-01

    Roč. 1768, č. 5 (2007), s. 1050-1058 ISSN 0005-2736 R&D Projects: GA AV ČR IAA400400503; GA AV ČR 1ET400400413; GA ČR GA203/05/2308; GA ČR(CZ) GD203/05/H001; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z40400503 Keywords : time-resolved fluorescence * mixed lipid/surfactant vesicles * Tween 80 * Brij 98 * interferon alfa-2b Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.640, year: 2007

  18. Comparison of rSP-C surfactant with natural and synthetic surfactants after late treatment in a rat model of the acute respiratory distress syndrome

    Science.gov (United States)

    Häfner, Dietrich; Germann, Paul-Georg; Hauschke, Dieter

    1998-01-01

    In a previous paper we showed that an SP-C containing surfactant preparation has similar activity as bovine-derived surfactants in a rat lung lavage model of the adult respiratory distress syndrome. In this study surfactant was given ten minutes after the last lavage (early treatment). In the present investigation we were interested how different surfactant preparations behave when they are administered 1 h after the last lavage (late treatment). Four protein containing surfactants (rSP-C surfactant, bLES, Infasurf and Survanta) were compared with three protein-free surfactants (ALEC, Exosurf and the phospholipid (PL) mixture of the rSP-C surfactant termed PL surfactant) with respect to their ability to improve gas exchange in this more stringent model when surfactant is given one hour after the last lavage. For better comparison of the surfactants the doses were related to phospholipids. The surfactants were given at doses of 25, 50 and 100 mg kg−1 body weight. The surfactants were compared to an untreated control group that was only ventilated for the whole experimental period. Tracheotomized rats (8–12 per dose and surfactant) were pressure-controlled ventilated (Siemens Servo Ventilator 900C) with 100% oxygen at a respiratory rate of 30 breaths min−1, inspiration expiration ratio of 1 : 2, peak inspiratory pressure of 28 cmH2O at positive endexpiratory pressure (PEEP) of 8 cmH2O. Animals were ventilated for one hour after the last lavage and thereafter the surfactants were intratracheally instilled. During the whole experimental period the ventilation was not changed. Partial arterial oxygen pressures (PaO2, mmHg) at 30 min and 120 min after treatment were used for statistical comparison. All protein containing surfactants caused a dose-dependent increase of the reduced PaO2 values at 30 min after treatment. The protein-free surfactants showed only weak dose-dependent increase in PaO2 values at this time. This difference between the

  19. Salivary agglutinin and lung scavenger receptor cysteine-rich glycoprotein 340 have broad anti-influenza activities and interactions with surfactant protein D that vary according to donor source and sialylation

    DEFF Research Database (Denmark)

    Hartshorn, Kevan L.; Ligtenberg, Antoon; White, Mitchell R.

    2006-01-01

    from this donor as compared with salivary gp-340 from another donor or several preparations of lung gp-340. Hence, the specificity of sialic acid linkages on gp-340 is an important determinant of anti-IAV activity. Gp-340 binds to SP-D (surfactant protein D), and we previously showed that lung gp-340...... has co-operative interactions with SP-D in viral neutralization and aggregation assays. We now report that salivary gp-340 can, in some cases, strongly antagonize certain antiviral activities of SP-D. This effect was associated with greater binding of salivary gp-340 to the carbohydrate recognition...... domain of SP-D as compared with the binding of lung gp-340. These findings may relate to inter-individual variations in innate defence against highly pathogenic IAV and to effects of aspiration of oral contents on SP-D-mediated lung functions....

  20. High yield expression of an AHL-lactonase from Bacillus sp. B546 in Pichia pastoris and its application to reduce Aeromonas hydrophila mortality in aquaculture

    Directory of Open Access Journals (Sweden)

    Bai Yingguo

    2010-05-01

    Full Text Available Abstract Background Aeromonas hydrophila is a serious pathogen and can cause hemorrhagic septicemia in fish. To control this disease, antibiotics and chemicals are widely used which can consequently result in "superbugs" and chemical accumulation in the food chain. Though vaccine against A. hydrophila is available, its use is limited due to multiple serotypes of this pathogen and problems of safety and efficacy. Another problem with vaccination is the ability to apply it to small fish especially in high numbers. In this study, we tried a new way to attenuate the A. hydrophila infection by using a quorum quenching strategy with a recombinant AHL-lactonase expressed in Pichia pastoris. Results The AHL-lactonase (AiiAB546 from Bacillus sp. B546 was produced extracellularly in P. pastoris with a yield of 3,558.4 ± 81.3 U/mL in a 3.7-L fermenter when using 3-oxo-C8-HSL as the substrate. After purification with a HiTrap Q Sepharose column, the recombinant homogenous protein showed a band of 33.6 kDa on SDS-PAGE, higher than the calculated molecular mass (28.14 kDa. Deglycosylation of AiiAB546 with Endo H confirmed the occurrence of N-glycosylation. The purified recombinant AiiAB546 showed optimal activity at pH 8.0 and 20°C, exhibited excellent stability at pH 8.0-12.0 and thermal stability at 70°C, was firstly confirmed to be significantly protease-resistant, and had wide substrate specificity. In application test, when co-injected with A. hydrophila in common carp, recombinant AiiAB546 decreased the mortality rate and delayed the mortality time of fish. Conclusions Our results not only indicate the possibility of mass-production of AHL-lactonase at low cost, but also open up a promising foreground of application of AHL-lactonase in fish to control A. hydrophila disease by regulating its virulence. To our knowledge, this is the first report on heterologous expression of AHL-lactonase in P. pastoris and attenuating A. hydrophila virulence by co

  1. Identification of microbial carotenoids and isoprenoid quinones from Rhodococcus sp. B7740 and its stability in the presence of iron in model gastric conditions.

    Science.gov (United States)

    Chen, Yashu; Xie, Bijun; Yang, Jifang; Chen, Jigang; Sun, Zhida

    2018-02-01

    Rhodococcus sp. B7740 is a newfound bacterium which was isolated from 25m deep seawater in the arctic. In this paper, Rhodococcus sp. B7740 was firstly discovered to produce abundant natural isoprenoids, including ubiquinone-4(UQ-4), 13 kinds of menaquinones, three rare aromatic carotenoids and more than one common carotenoid. These compounds were identified by UV-Visible, HPLC-APCI-MS/MS and HRMS spectra. Results demonstrated that Rhodococcus sp. B7740 might be a worthy source of natural isoprenoids especially for scarce aromatic carotenoids. Among them, isorenieratene with 528.3762Da (calculated for 528.3756Da, error: 1.1ppm), a carotenoid with aromatic ring, was purified by HSCCC. The stability of isorenieratene under the mimical gastric conditions was measured compared with common dietary carotenoids, β-carotene and lutein. Unlike β-carotene and lutein, isorenieratene exhibited rather stable in the presence of free iron or heme iron. Its high retention rate in gastrointestinal tract after ingestion indicates the benefits for health. Copyright © 2017. Published by Elsevier Ltd.

  2. Surfactant therapy in late preterm infants

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    Murat Yurdakök

    2013-06-01

    Full Text Available Late preterm (LPT neonates are at a high risk for respiratory distress soon after birth due to respiratory distress syndrome (RDS, transient tachypnea of the newborn, persistent pulmonary hypertension, and pneumonia along with an increased need for surfactant replacement therapy, continuous positive airway pressure, and ventilator support when compared with the term neonates. In the past, studies on outcomes of infants with respiratory distress have primarily focused on extremely premature infants, leading to a gap in knowledge and understanding of the developmental biology and mechanism of pulmonary diseases in LPT neonates. Surfactant deficiency is the most frequent etiology of RDS in very preterm and moderately preterm infants, while cesarean section and lung infection play major roles in RDS development in LPT infants. The clinical presentation and the response to surfactant therapy in LPT infants may be different than that seen in very preterm infants. Incidence of pneumonia and occurrence of pneumothorax are significantly higher in LPT and term infants. High rates of pneumonia in these infants may result in direct injury to the type II alveolar cells of the lung with decreasing synthesis, release, and processing of surfactant. Increased permeability of the alveolar capillary membrane to both fluid and solutes is known to result in entry of plasma proteins into the alveolar hypophase, further inhibiting the surface properties of surfactant. However, the oxygenation index value do not change dramatically after ventilation or surfactant administration in LPT infants with RDS compared to very preterm infants. These finding may indicate a different pathogenesis of RDS in late preterm and term infants. In conclusion, surfactant therapy may be of significant benefit in LPT infants with serious respiratory failure secondary to a number of insults. However, optimal timing and dose of administration are not so clear in this group. Additional

  3. Effect of ethyleneoxide groups of anionic surfactants on lipase activity.

    Science.gov (United States)

    Magalhães, Solange S; Alves, Luís; Sebastião, Marco; Medronho, Bruno; Almeida, Zaida L; Faria, Tiago Q; Brito, Rui M M; Moreno, Maria J; Antunes, Filipe E

    2016-09-01

    The use of enzymes in laundry and dish detergent products is growing. Such tendency implies dedicated studies to understand surfactant-enzyme interactions. The interactions between surfactants and enzymes and their impact on the catalytic efficiency represent a central problem and were here evaluated using circular dichroism, dynamic light scattering, and enzyme activity determinations. This work focuses on this key issue by evaluating the role of the ethyleneoxide (EO) groups of anionic surfactants on the structure and activity of a commercial lipase, and by focusing on the protein/surfactant interactions at a molecular level. The conformational changes and enzymatic activity of the protein were evaluated in the presence of sodium dodecyl sulfate (SDS also denoted as SLE 0 S) and of sodium lauryl ether sulfate with two EO units (SLE 2 S). The results strongly suggest that the presence of EO units in the surfactant polar headgroup determines the stability and the activity of the enzyme. While SDS promotes enzyme denaturation and consequent loss of activity, SLE 2 S preserves the enzyme structure and activity. The data further highlights that the electrostatic interactions among the protein groups are changed by the presence of the adsorbed anionic surfactants being such absorption mainly driven by hydrophobic interactions. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1276-1282, 2016. © 2016 American Institute of Chemical Engineers.

  4. Biophysical inhibition of synthetic vs. naturally-derived pulmonary surfactant preparations by polymeric nanoparticles.

    Science.gov (United States)

    Beck-Broichsitter, Moritz; Ruppert, Clemens; Schmehl, Thomas; Günther, Andreas; Seeger, Werner

    2014-01-01

    Reasonable suspicion has accumulated that inhaled nano-scale particulate matter influences the biophysical function of the pulmonary surfactant system. Hence, it is evident to provide novel insights into the extent and mechanisms of nanoparticle-surfactant interactions in order to facilitate the fabrication of safe nanomedicines suitable for pulmonary applications. Negatively- and positively-charged poly(styrene) nanoparticles (diameters of ~100nm) served as model carriers. Nanoparticles were incubated with several synthetic and naturally-derived pulmonary surfactants to characterize the sensitivity of each preparation to biophysical inactivation. Changes in surface properties (i.e. adsorption and dynamic surface tension behavior) were monitored in a pulsating bubble surfactometer. Both nanoparticle formulations revealed a dose-dependent influence on the biophysical behavior of all investigated pulmonary surfactants. However, the surfactant sensitivity towards inhibition depended on both the carrier type, where negatively-charged nanoparticles showed increased inactivation potency compared to their positively-charged counterparts, and surfactant composition. Among the surfactants tested, synthetic mixtures (i.e. phospholipids, phospholipids supplemented with surfactant protein B, and Venticute®) were more susceptible to surface-activity inhibition as the more complex naturally-derived preparations (i.e. Alveofact® and large surfactant aggregates isolated from rabbit bronchoalveolar lavage fluid). Overall, nanoparticle characteristics and surfactant constitution both influence the extent of biophysical inhibition of pulmonary surfactants. © 2013.

  5. Coacervation with surfactants: From single-chain surfactants to gemini surfactants.

    Science.gov (United States)

    Zhao, Weiwei; Wang, Yilin

    2017-01-01

    Coacervation is a spontaneous process during which a colloidal dispersion separates into two immiscible liquid phases: a colloid-rich liquid phase in equilibrium with a diluted phase. Coacervation is usually divided into simple coacervation and complex coacervation according to the number of components. Surfactant-based coacervation normally contains traditional single-chain surfactants. With the development of surfactants, gemini surfactants with two amphiphilic moieties have been applied to form coacervation. This review summarizes the development of simple coacervation and complex coacervation in the systems of single-chain surfactants and gemini surfactants. Simple coacervation in surfactant solutions with additives or at elevated temperature and complex coacervation in surfactant/polymer mixtures by changing charge densities, molecular weight, ionic strength, pH, or temperature are reviewed. The comparison between gemini surfactants and corresponding monomeric single-chain surfactants reveals that the unique structures of gemini surfactants endow them with higher propensity to generate coacervation. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. The Pulmonary Surfactant: Impact of Tobacco Smoke and Related Compounds on Surfactant and Lung Development

    Directory of Open Access Journals (Sweden)

    Scott J Elliott

    2004-03-01

    Full Text Available Abstract Cigarette smoking, one of the most pervasive habits in society, presents many well established health risks. While lung cancer is probably the most common and well documented disease associated with tobacco exposure, it is becoming clear from recent research that many other diseases are causally related to smoking. Whether from direct smoking or inhaling environmental tobacco smoke (ETS, termed secondhand smoke, the cells of the respiratory tissues and the lining pulmonary surfactant are the first body tissues to be directly exposed to the many thousands of toxic chemicals in tobacco. Considering the vast surface area of the lung and the extreme attenuation of the blood-air barrier, it is not surprising that this organ is the primary route for exposure, not just to smoke but to most environmental contaminants. Recent research has shown that the pulmonary surfactant, a complex mixture of phospholipids and proteins, is the first site of defense against particulates or gas components of smoke. However, it is not clear what effect smoke has on the surfactant. Most studies have demonstrated that smoking reduces bronchoalveolar lavage phospholipid levels. Some components of smoke also appear to have a direct detergent-like effect on the surfactant while others appear to alter cycling or secretion. Ultimately these effects are reflected in changes in the dynamics of the surfactant system and, clinically in changes in lung mechanics. Similarly, exposure of the developing fetal lung through maternal smoking results in postnatal alterations in lung mechanics and higher incidents of wheezing and coughing. Direct exposure of developing lung to nicotine induces changes suggestive of fetal stress. Furthermore, identification of nicotinic receptors in fetal lung airways and corresponding increases in airway connective tissue support a possible involvement of nicotine in postnatal asthma development. Finally, at the level of the alveoli of the lung

  7. A systems approach to mapping transcriptional networks controlling surfactant homeostasis

    Directory of Open Access Journals (Sweden)

    Dave Vrushank

    2010-07-01

    Full Text Available Abstract Background Pulmonary surfactant is required for lung function at birth and throughout life. Lung lipid and surfactant homeostasis requires regulation among multi-tiered processes, coordinating the synthesis of surfactant proteins and lipids, their assembly, trafficking, and storage in type II cells of the lung. The mechanisms regulating these interrelated processes are largely unknown. Results We integrated mRNA microarray data with array independent knowledge using Gene Ontology (GO similarity analysis, promoter motif searching, protein interaction and literature mining to elucidate genetic networks regulating lipid related biological processes in lung. A Transcription factor (TF - target gene (TG similarity matrix was generated by integrating data from different analytic methods. A scoring function was built to rank the likely TF-TG pairs. Using this strategy, we identified and verified critical components of a transcriptional network directing lipogenesis, lipid trafficking and surfactant homeostasis in the mouse lung. Conclusions Within the transcriptional network, SREBP, CEBPA, FOXA2, ETSF, GATA6 and IRF1 were identified as regulatory hubs displaying high connectivity. SREBP, FOXA2 and CEBPA together form a common core regulatory module that controls surfactant lipid homeostasis. The core module cooperates with other factors to regulate lipid metabolism and transport, cell growth and development, cell death and cell mediated immune response. Coordinated interactions of the TFs influence surfactant homeostasis and regulate lung function at birth.

  8. MICROBIAL SURFACTANTS. I. GLYCOLIPIDS

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    Pirog T. Р.

    2014-02-01

    Full Text Available The review is devoted to surface-active glycolipids. The general characteristics, the physiological role of the rhamnolipids, trehalose lipids, sophorolipids, mannosylerythritol lipids and their traditional producers — the representatives of the genera Pseudozyma, Pseudomonas, Rhodococcus and Candida are given. The detailed analysis of the chemical structure, the stages of the biosynthesis and the regulation of some low molecular glycolipids are done. The own experimental data concerning the synthesis intensification, the physiological role and the practical use of Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 surfactants, which are a complex of the glyco-, phospho-, amino- and neutral lipids (glycolipids of all strains are presented by trehalose mycolates are summarized. It was found that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants have protective, antimicrobial and antiadhesive properties. It was shown that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants preparation of cultural liquid intensified the degradation of oil in water due to the activation of the natural petroleum-oxidizing microflora.

  9. Surfactants at the Design Limit.

    Science.gov (United States)

    Czajka, Adam; Hazell, Gavin; Eastoe, Julian

    2015-08-04

    This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

  10. Self-Assembling Peptide Surfactants A6K and A6D Adopt a-Helical Structures Useful for Membrane Protein Stabilization

    Directory of Open Access Journals (Sweden)

    Furen Zhuang

    2011-10-01

    Full Text Available Elucidation of membrane protein structures have been greatly hampered by difficulties in producing adequately large quantities of the functional protein and stabilizing them. A6D and A6K are promising solutions to the problem and have recently been used for the rapid production of membrane-bound G protein-coupled receptors (GPCRs. We propose that despite their short lengths, these peptides can adopt α-helical structures through interactions with micelles formed by the peptides themselves. These α-helices are then able to stabilize α-helical motifs which many membrane proteins contain. We also show that A6D and A6K can form β-sheets and appear as weak hydrogels at sufficiently high concentrations. Furthermore, A6D and A6K together in sodium dodecyl sulfate (SDS can form expected β-sheet structures via a surprising α-helical intermediate.

  11. Theoretical model to investigate the alkyl chain and anion dependent interactions of gemini surfactant with bovine serum albumin.

    Science.gov (United States)

    Vishvakarma, Vijay K; Kumari, Kamlesh; Patel, Rajan; Dixit, V S; Singh, Prashant; Mehrotra, Gopal K; Chandra, Ramesh; Chakrawarty, Anand Kumar

    2015-05-15

    Surfactants are used to prevent the irreversible aggregation of partially refolded proteins and they also assist in protein refolding. We have reported the design and screening of gemini surfactant to stabilize bovine serum albumin (BSA) with the help of computational tool (iGEMDOCK). A series of gemini surfactant has been designed based on bis-N-alkyl nicotinate dianion via varying the alkyl group and anion. On changing the alkyl group and anion of the surfactant, the value of Log P changes means polarity of surfactant can be tuned. Further, the virtual screening of the gemini surfactant has been carried out based on generic evolutionary method. Herein, thermodynamic data was studied to determine the potential of gemini surfactant as BSA stabilizer. Computational tools help to find out the efficient gemini surfactant to stabilize the BSA rather than to use the surfactant randomly and directionless for the stabilization. It can be confirmed through the experimental techniques. Previously, researcher synthesized one of the designed and used gemini surfactant to stabilize the BSA and their interactions were confirmed through various techniques and computational docking. But herein, the authors find the most competent gemini surfactant to stabilize BSA using computational tools on the basis of energy score. Different from the single chain surfactant, the gemini surfactants exhibit much stronger electrostatic and hydrophobic interactions with the protein and are thus effective at much lower concentrations. Based on the present study, it is expected that gemini surfactants may prove useful in the protein stabilization operations and may thus be effectively employed to circumvent the problem of misfolding and aggregation. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Surfactant phosphatidylcholine metabolism and surfactant function in preterm, ventilated lambs

    International Nuclear Information System (INIS)

    Jobe, A.H.; Ikegami, M.; Seidner, S.R.; Pettenazzo, A.; Ruffini, L.

    1989-01-01

    Preterm lambs were delivered at 138 days gestational age and ventilated for periods up to 24 h in order to study surfactant metabolism and surfactant function. The surfactant-saturated phosphatidylcholine pool in the alveolar wash was 13 +/- 4 mumol/kg and did not change from 10 min to 24 h after birth. Trace amounts of labeled natural sheep surfactant were mixed with fetal lung fluid at birth. By 24 h, 80% of the label had become lung-tissue-associated, yet there was no loss of label from phosphatidylcholine in the lungs when calculated as the sum of the lung tissue plus alveolar wash. De novo synthesized phosphatidylcholine was labeled with choline given by intravascular injection at 1 h of age. Labeled phosphatidylcholine accumulated in the lung tissue linearly to 24 h, and the labeled phosphatidylcholine moved through lamellar body to alveolar pools. The turnover time for alveolar phosphatidylcholine was estimated to be about 13 h, indicating an active metabolic pool. A less surface-active surfactant fraction recovered as a supernatant after centrifugation of the alveolar washes at 40,000 x g increased from birth to 10 min of ventilation, but no subsequent changes in the distribution of surfactant phosphatidylcholine in surfactant fractions occurred. The results were consistent with recycling pathway(s) that maintained surface-active surfactant pools in preterm ventilated lambs

  13. Structure-function relationships in pulmonary surfactant membranes: from biophysics to therapy.

    Science.gov (United States)

    Lopez-Rodriguez, Elena; Pérez-Gil, Jesús

    2014-06-01

    Pulmonary surfactant is an essential lipid-protein complex to maintain an operative respiratory surface at the mammalian lungs. It reduces surface tension at the alveolar air-liquid interface to stabilise the lungs against physical forces operating along the compression-expansion breathing cycles. At the same time, surfactant integrates elements establishing a primary barrier against the entry of pathogens. Lack or deficiencies of the surfactant system are associated with respiratory pathologies, which treatment often includes supplementation with exogenous materials. The present review summarises current models on the molecular mechanisms of surfactant function, with particular emphasis in its biophysical properties to stabilise the lungs and the molecular alterations connecting impaired surfactant with diseased organs. It also provides a perspective on the current surfactant-based strategies to treat respiratory pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Micropipette Technique Study of Natural and Synthetic Lung Surfactants at the Air–Water Interface

    DEFF Research Database (Denmark)

    Ortiz, Elisa Parra; Kinoshita, K.; Needham, D.

    2016-01-01

    The present study is a microscopic interfacial characterization of a series of lung surfactant materials performed with the micropipette technique. The advantages of this technique include the measurement of equilibrium and dynamic surface tensions while acquiring structural and dynamic information...... at microscopic air-water interfaces in real time and upon compression. Here, we characterized a series of animal-derived and synthetic lung surfactant formulations, including native surfactant obtained from porcine lungs (NS); the commercial Curosurf, Infasurf, and Survanta; and a synthetic Super Mini-B (SMB...... but neither in the other clinical surfactants nor in protein-free preparations. Finally, the connection between this data and the observations from the lung surfactant literature concerning the widely reported "near-zero surface tension" for lung surfactant films and intact alveolar surfaces is also discussed...

  15. Novel Halomonas sp. B15 isolated from Larnaca Salt Lake in Cyprus that generates vanillin and vanillic acid from ferulic acid.

    Science.gov (United States)

    Vyrides, Ioannis; Agathangelou, Maria; Dimitriou, Rodothea; Souroullas, Konstantinos; Salamex, Anastasia; Ioannou, Aristostodimos; Koutinas, Michalis

    2015-08-01

    Vanillin is a high value added product with many applications in the food, fragrance and pharmaceutical industries. A natural and low-cost method to produce vanillin is by microbial bioconversions through ferulic acid. Until now, limited microorganisms have been found capable of bioconverting ferulic acid to vanillin at high yield. This study aimed to screen halotolerant strains of bacteria from Larnaca Salt Lake which generate vanillin and vanillic acid from ferulic acid. From a total of 50 halotolenant/halophilic strains 8 grew in 1 g/L ferulic acid and only 1 Halomonas sp. B15 and 3 Halomonas elognata strains were capable of bioconverting ferulic acid to vanillic acid at 100 g NaCl/L. The highest vanillic acid (365 mg/L) at these conditions generated by Halomonas sp. B15 which corresponds to ferulic acid bioconversion yield of 36.5%. Using the resting cell technique with an initial ferulic acid concentration of 0.5 g/L at low salinity, the highest production of vanillin (245 mg/L) took place after 48 h, corresponding to a bioconversion yield of 49%. This is the first reported Halomonas sp. with high yield of vanillin production from ferulic acid at low salinity.

  16. Respiratory Mechanics and Gas Exchange: The Effect of Surfactants

    Science.gov (United States)

    Jbaily, Abdulrahman; Szeri, Andrew J.

    2017-11-01

    The purpose of the lung is to exchange gases, primarily oxygen and carbon dioxide, between the atmosphere and the circulatory system. To enable this exchange, the airways in the lungs terminate in some 300 million alveoli that provide adequate surface area for transport. During breathing, work must be done to stretch various tissues to accommodate a greater volume of gas. Considerable work must also be done to expand the liquid lining (hypophase) that coats the interior surfaces of the alveoli. This is enabled by a surface active lipo-protein complex, known as pulmonary surfactant, that modifies the surface tension at the hypophase-air interface. Surfactants also serve as physical barriers that modify the rate of gas transfer across interfaces. We develop a mathematical model to study the action of pulmonary surfactant and its determinative contributions to breathing. The model is used to explore the influence of surfactants on alveolar mechanics and on gas exchange: it relates the work of respiration at the level of the alveolus to the gas exchange rate through the changing influence of pulmonary surfactant over the breathing cycle. This work is motivated by a need to develop improved surfactant replacement therapies to treat serious medical conditions.

  17. ADSORPTION OF SURFACTANT ON CLAYS

    Science.gov (United States)

    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  18. Surfactant monitoring by foam generation

    Science.gov (United States)

    Mullen, Ken I.

    1997-01-01

    A device for monitoring the presence or absence of active surfactant or other surface active agents in a solution or flowing stream based on the formation of foam or bubbles is presented. The device detects the formation of foam with a light beam or conductivity measurement. The height or density of the foam can be correlated to the concentration of the active surfactant present.

  19. The Mycobacterium tuberculosis cell-surface glycoprotein apa as a potential adhesin to colonize target cells via the innate immune system pulmonary C-type lectin surfactant protein A.

    Science.gov (United States)

    Ragas, Aude; Roussel, Lucie; Puzo, Germain; Rivière, Michel

    2007-02-23

    Tuberculosis is still a major health problem, and understanding the mechanism by which Mycobacterium tuberculosis (Mtb) invades and colonizes its host target cells remains an important issue for the control of infection. The innate immune system C-type lectins (C-TLs), including the human pulmonary surfactant protein A (PSP-A), have been recently identified as determinant players in the early recognition of the invading pathogen and in mounting the host defense response. Although the antigenic lipoglycan mannosylated lipoarabinomannan is currently considered to be the major C-TL target on the mycobacterial surface, the recognition by some C-TLs of the only mycobacterial species composing the "Mtb complex" indicates that mannosylated lipoarabinomannan cannot account alone for this specificity. Thus, we searched for the mycobacterial molecules targeted by human PSP-A, focusing our attention on the Mtb surface glycoproteins. We developed an original functional proteomic approach based on a lectin blot assay using crude human bronchoalveolar lavage fluid as a source of physiological PSP-A. Combined with selective cell-surface protein extraction and mass spectrometry peptide mapping, this strategy allowed us to identify the Apa (alanine- and proline-rich antigenic) glycoprotein as new potential target for PSP-A. This result was supported by direct binding of PSP-A to purified Apa. Moreover, EDTA addition or deglycosylation of purified Apa samples completely abolished the interaction, demonstrating that the interaction is calcium- and mannose-dependent, as expected. Finally, we provide convincing evidence that Apa, formerly considered as mainly secreted, is associated with the cell wall for a sufficiently long time to aid in the attachment of PSP-A. Because, to date, Apa seems to be restricted to the Mtb complex strains, we propose that it may account for the selective recognition of those strains by PSP-A and other immune system C-TLs containing homologous functional

  20. Lipoteichoic acid induces surfactant protein-A biosynthesis in human alveolar type II epithelial cells through activating the MEK1/2-ERK1/2-NF-κB pathway

    Directory of Open Access Journals (Sweden)

    Liu Feng-Lin

    2012-10-01

    Full Text Available Abstract Background Lipoteichoic acid (LTA, a gram-positive bacterial outer membrane component, can cause septic shock. Our previous studies showed that the gram-negative endotoxin, lipopolysaccharide (LPS, could induce surfactant protein-A (SP-A production in human alveolar epithelial (A549 cells. Objectives In this study, we further evaluated the effect of LTA on SP-A biosynthesis and its possible signal-transducing mechanisms. Methods A549 cells were exposed to LTA. Levels of SP-A, nuclear factor (NF-κB, extracellular signal-regulated kinase 1/2 (ERK1/2, and mitogen-activated/extracellular signal-regulated kinase kinase (MEK1 were determined. Results Exposure of A549 cells to 10, 30, and 50 μg/ml LTA for 24 h did not affect cell viability. Meanwhile, when exposed to 30 μg/ml LTA for 1, 6, and 24 h, the biosynthesis of SP-A mRNA and protein in A549 cells significantly increased. As to the mechanism, LTA enhanced cytosolic and nuclear NF-κB levels in time-dependent manners. Pretreatment with BAY 11–7082, an inhibitor of NF-κB activation, significantly inhibited LTA-induced SP-A mRNA expression. Sequentially, LTA time-dependently augmented phosphorylation of ERK1/2. In addition, levels of phosphorylated MEK1 were augmented following treatment with LTA. Conclusions Therefore, this study showed that LTA can increase SP-A synthesis in human alveolar type II epithelial cells through sequentially activating the MEK1-ERK1/2-NF-κB-dependent pathway.

  1. Interaction of bovine serum albumin with N-acyl amino acid based anionic surfactants: Effect of head-group hydrophobicity.

    Science.gov (United States)

    Ghosh, Subhajit; Dey, Joykrishna

    2015-11-15

    The function of a protein depends upon its structure and surfactant molecules are known to alter protein structure. For this reason protein-surfactant interaction is important in biological, pharmaceutical, and cosmetic industries. In the present work, interactions of a series of anionic surfactants having the same hydrocarbon chain length, but different amino acid head group, such as l-alanine, l-valine, l-leucine, and l-phenylalanine with the transport protein, bovine serum albumin (BSA), were studied at low surfactant concentrations using fluorescence and circular dichroism (CD) spectroscopy, and isothermal titration calorimetry (ITC). The results of fluorescence measurements suggest that the surfactant molecules bind simultaneously to the drug binding site I and II of the protein subdomain IIA and IIIA, respectively. The fluorescence as well as CD spectra suggest that the conformation of BSA goes to a more structured state upon surfactant binding at low concentrations. The binding constants of the surfactants were determined by the use of fluorescence as well as ITC measurements and were compared with that of the corresponding glycine-derived surfactant. The binding constant values clearly indicate a significant head-group effect on the BSA-surfactant interaction and the interaction is mainly hydrophobic in nature. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. MICROBIAL SURFACTANTS IN ENVIRONMENTAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2015-08-01

    Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

  3. Surfactant Membrane Phases Containing Mixtures of Hydrocarbon and Fluorocarbon Surfactants

    International Nuclear Information System (INIS)

    de Campo, Liliana; Warr, G.G.

    2005-01-01

    Full text: We describe the structure and stability of sponge and lamellar phases comprising mixtures of hydrocarbon and fluorocarbon surfactants. Such mixtures can show limited miscibility with each other, forming for example coexisting populations of hydrocarbon rich and fluorocarbon rich micelles under some circumstances. Our system is based on the well-characterised lamellar and sponge phases of cetylpyridinium chloride, hexanol and 0.2M brine, into which the partially fluorinated surfactant N-1H,1H,2H,2H-tridecafluorooctylpyridinium chloride is incorporated. By probing the structures with SAXS (small angle x-ray scattering) and SANS (small angle neutron scattering) using contrast variation, and by characterizing the dynamic properties with dynamic light scattering, we will describe the effect of incorporating the fluorinated surfactant on the phase equilibria and properties of the surfactant membrane structures. (authors)

  4. Dysfunction of pulmonary surfactant mediated by phospholipid oxidation is cholesterol-dependent.

    Science.gov (United States)

    Al-Saiedy, Mustafa; Pratt, Ryan; Lai, Patrick; Kerek, Evan; Joyce, Heidi; Prenner, Elmar; Green, Francis; Ling, Chang-Chun; Veldhuizen, Ruud; Ghandorah, Salim; Amrein, Matthias

    2018-04-01

    Pulmonary surfactant forms a cohesive film at the alveolar air-lung interface, lowering surface tension, and thus reducing the work of breathing and preventing atelectasis. Surfactant function becomes impaired during inflammation due to degradation of the surfactant lipids and proteins by free radicals. In this study, we examine the role of reactive nitrogen (RNS) and oxygen (ROS) species on surfactant function with and without physiological cholesterol levels (5-10%). Surface activity was assessed in vitro in a captive bubble surfactometer (CBS). Surfactant chemistry, monolayer fluidity and thermodynamic behavior were also recorded before and after oxidation. We report that physiologic amounts of cholesterol combined with oxidation results in severe impairment of surfactant function. We also show that surfactant polyunsaturated phospholipids are the most susceptible to oxidative alteration. Membrane thermodynamic experiments showed significant surfactant film stiffening after free radical exposure in the presence of cholesterol. These results point to a previously unappreciated role for cholesterol in amplifying defects in surface activity caused by oxidation of pulmonary surfactant, a finding that may have implications for treating several lung diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Rapid Biosynthesis of Silver Nanoparticles Based on Flocculation and Reduction of an Exopolysaccharide from Arthrobacter sp. B4: Its Antimicrobial Activity and Phytotoxicity

    Directory of Open Access Journals (Sweden)

    Li Yumei

    2017-01-01

    Full Text Available Silver nanoparticles (AgNPs were rapidly synthesized using an exopolysaccharide from Arthrobacter sp. B4 (B4-EPS. The optimum condition for AgNPs synthesis was under the concentration of 5 g/L B4-EPS and 1 mM AgNO3 at 80°C between pH 7.0 and 8.0. The resulting AgNPs displayed a face-centred-cubic structure with the size range from 9 nm to 72 nm. Further analysis showed that flocculation and reduction of B4-EPS played a pivotal role in the formation of AgNPs. Furthermore, these nanoparticles exhibited great stability, excellent antimicrobial activity, and low phytotoxicity. The aforementioned data provide a feasible and efficient approach for green synthesis of AgNPs using microbial polysaccharides with flocculation and reduction activity, which will be promising in medical filed.

  6. The protective effect of different airway humidification liquids to lung after tracheotomy in traumatic brain injury: The role of pulmonary surfactant protein-A (SP-A).

    Science.gov (United States)

    Su, Xinyang; Li, Zefu; Wang, Meilin; Li, Zhenzhu; Wang, Qingbo; Lu, Wenxian; Li, Xiaoli; Zhou, Youfei; Xu, Hongmei

    2016-02-10

    The purpose of this study was to establish a rat model of a brain injury with tracheotomy and compared the wetting effects of different airway humidification liquids, afterward, the best airway humidification liquid was selected for the clinical trial, thus providing a theoretical basis for selecting a proper airway humidification liquid in a clinical setting. Rats were divided into a sham group, group A (0.9% NaCl), group B (0.45% NaCl), group C (0.9% NaCl+ambroxol) and group D (0.9% NaCl+Pulmicort). An established rat model of traumatic brain injury with tracheotomy was used. Brain tissue samples were taken to determine water content, while lung tissue samples were taken to determine wet/dry weight ratio (W/D), histological changes and expression levels of SP-A mRNA and SP-A protein. 30 patients with brain injury and tracheotomy were selected and divided into two groups based on the airway humidification liquid instilled in the trachea tube, 0.45% NaCl and 0.9% NaCl+ambroxol. Blood was then extracted from the patients to measure the levels of SP-A, interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α). The difference between group C and other groups in lung W/D and expression levels of SP-A mRNA and SP-A protein was significant (Phumidification liquid. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Surfactant-free Colloidal Particles with Specific Binding Affinity.

    Science.gov (United States)

    van der Wel, Casper; Bossert, Nelli; Mank, Quinten J; Winter, Marcel G T; Heinrich, Doris; Kraft, Daniela J

    2017-09-26

    Colloidal particles with specific binding affinity are essential for in vivo and in vitro biosensing, targeted drug delivery, and micrometer-scale self-assembly. Key to these techniques are surface functionalizations that provide high affinities to specific target molecules. For stabilization in physiological environments, current particle coating methods rely on adsorbed surfactants. However, spontaneous desorption of these surfactants typically has an undesirable influence on lipid membranes. To address this issue and create particles for targeting molecules in lipid membranes, we present here a surfactant-free coating method that combines high binding affinity with stability at physiological conditions. After activating charge-stabilized polystyrene microparticles with EDC/Sulfo-NHS, we first coat the particles with a specific protein and subsequently covalently attach a dense layer of poly(ethyelene) glycol. This polymer layer provides colloidal stability at physiological conditions as well as antiadhesive properties, while the protein coating provides the specific affinity to the targeted molecule. We show that NeutrAvidin-functionalized particles bind specifically to biotinylated membranes and that Concanavalin A-functionalized particles bind specifically to the glycocortex of Dictyostelium discoideum cells. The affinity of the particles changes with protein density, which can be tuned during the coating procedure. The generic and surfactant-free coating method reported here transfers the high affinity and specificity of a protein onto colloidal polystyrene microparticles.

  8. Mercury (II) removal by resistant bacterial isolates and mercuric (II) reductase activity in a new strain of Pseudomonas sp. B50A.

    Science.gov (United States)

    Giovanella, Patricia; Cabral, Lucélia; Bento, Fátima Menezes; Gianello, Clesio; Camargo, Flávio Anastácio Oliveira

    2016-01-25

    This study aimed to isolate mercury resistant bacteria, determine the minimum inhibitory concentration for Hg, estimate mercury removal by selected isolates, explore the mer genes, and detect and characterize the activity of the enzyme mercuric (II) reductase produced by a new strain of Pseudomonas sp. B50A. The Hg removal capacity of the isolates was determined by incubating the isolates in Luria Bertani broth and the remaining mercury quantified by atomic absorption spectrophotometry. A PCR reaction was carried out to detect the merA gene and the mercury (II) reductase activity was determined in a spectrophotometer at 340 nm. Eight Gram-negative bacterial isolates were resistant to high mercury concentrations and capable of removing mercury, and of these, five were positive for the gene merA. The isolate Pseudomonas sp. B50A removed 86% of the mercury present in the culture medium and was chosen for further analysis of its enzyme activity. Mercuric (II) reductase activity was detected in the crude extract of this strain. This enzyme showed optimal activity at pH 8 and at temperatures between 37 °C and 45 °C. The ions NH4(+), Ba(2+), Sn(2+), Ni(2+) and Cd(2+) neither inhibited nor stimulated the enzyme activity but it decreased in the presence of the ions Ca(2+), Cu(+) and K(+). The isolate and the enzyme detected were effective in reducing Hg(II) to Hg(0), showing the potential to develop bioremediation technologies and processes to clean-up the environment and waste contaminated with mercury. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Treatment with exogenous surfactant stimulates endogenous surfactant synthesis in premature infants with respiratory distress syndrome

    NARCIS (Netherlands)

    Bunt, JEH; Carnielli, VP; Janssen, DJ; Wattimena, JLD; Hop, WC; Sauer, PJ; Zimmermann, LJI

    2000-01-01

    Objective: Treatment of preterm infants with respiratory distress syndrome (RDS) with exogenous surfactant has greatly improved clinical outcome. Some infants require multiple doses, and it has not been studied whether these large amounts of exogenous surfactant disturb endogenous surfactant

  10. Biomimetic oligosaccharide and peptide surfactant polymers designed for cardiovascular biomaterials

    Science.gov (United States)

    Ruegsegger, Mark Andrew

    A common problem associated with cardiovascular devices is surface induced thrombosis initiated by the rapid, non-specific adsorption of plasma proteins onto the biomaterial surface. Control of the initial protein adsorption is crucial to achieve the desired longevity of the implanted biomaterial. The cell membrane glycocalyx acts as a non-thrombogenic interface through passive (dense oligosaccharide structures) and active (ligand/receptor interactions) mechanisms. This thesis is designed to investigate biomimicry of the cell glycocalyx to minimize non-specific protein adsorption and promote specific ligand/receptor interactions. Biomimetic macromolecules were designed through the molecular-scale engineering of polymer surfactants, utilizing a poly(vinyl amine) (PVAm) backbone to which hydrophilic (dextran, maltose, peptide) and hydrophobic alkyl (hexanoyl or hexanal) chains are simultaneously attached. The structure was controlled through the molar feed ratio of hydrophobic-to-hydrophilic groups, which also provided control of the solution and surface-active properties. To mimic passive properties, a series of oligomaltose surfactants were synthesized with increasing saccharide length (n = 2, 7, 15 where n is number of glucose units) to investigate the effect of coating height on protein adsorption. The surfactants were characterized by infra red (IR) and nuclear magnetic resonance (NMR) spectroscopies for structural properties and atomic force microscopy (AFM) and contact angle goniometry for surface activity. Protein adsorption under dynamic flow (5 dyn/cm2) was reduced by 85%--95% over the bare hydrophobic substrate; platelet adhesion dropped by ˜80% compared to glass. Peptide ligands were incorporated into the oligosaccharide surfactant to promote functional activity of the passive coating. The surfactants were synthesized to contain 0%, 25%, 50%, 75%, and 100% peptide ligand density and were stable on hydrophobic surfaces. The peptide surface density was

  11. Competitive adsorption of monoclonal antibodies and nonionic surfactants at solid hydrophobic surfaces

    DEFF Research Database (Denmark)

    Kapp, Sebastian J; Larsson, Iben; van de Weert, Marco

    2015-01-01

    , such as infusion bags and i.v. lines. Total internal reflection fluorescence and quartz crystal microbalance with dissipation monitoring were used to follow and quantify this. Furthermore, the influence of the nonionic surfactant polysorbate 80 (PS80) on the adsorption process of these two antibodies...... was investigated. Despite belonging to two different IgG subclasses, both antibodies displayed comparable adsorption behavior. Both antibodies readily adsorbed in the absence of PS80, whereas adsorption was reduced in the presence of 30 mg/L surfactant. The sequence of exposure of the surfactant and protein...... to the surface was found to have a major influence on the extent of protein adsorption. Although only a fraction of adsorbed protein could be removed by rinsing with 30 mg/L surfactant solution, adsorption was entirely prevented when surfaces were pre-exposed to PS80. © 2014 Wiley Periodicals, Inc...

  12. A model of flow and surfactant transport in an oscillatory alveolus partially filled with liquid

    Science.gov (United States)

    Wei, Hsien-Hung; Fujioka, Hideki; Hirschl, Ronald B.; Grotberg, James B.

    2005-03-01

    The flow and transport in an alveolus are of fundamental importance to partial liquid ventilation, surfactant transport, pulmonary drug administration, cell-cell signaling pathways, and gene therapy. We model the system in which an alveolus is partially filled with liquid in the presence of surfactants. By assuming a circular interface due to sufficiently strong surface tension and small surfactant activity, we combine semianalytical and numerical techniques to solve the Stokes flow and the surfactant transport equations. In the absence of surfactants, there is no steady streaming because of reversibility of Stokes flow. The presence of surfactants, however, induces a nontrivial cycle-averaged surfactant concentration gradient along the interface that generates steady streaming. The steady streaming patterns (e.g., number of vortices) particularly depend on the ratio of inspiration to expiration periods (I :E ratio) and the sorption parameter K. For an insoluble surfactant, a single vortex is formed when the I :E ratio is either smaller or larger than 1:1, but the recirculations have opposite directions in the two cases. A soluble surfactant can lead to more complex flow patterns such as three vortices or saddle-point flow structures. The estimated unsteady velocity is 10-3cm/s, and the corresponding Péclet number for transporting respiratory gas is O(1). For a cell-cell signaling molecule such as surfactant-associated protein-A for regulating surfactant secretion, the Péclet number could be O(10) or higher. Convection is either comparable to or more dominant than diffusion in these processes. The estimated steady velocity ranges from 10-6to10-4cm /s, depending on I :E and K, and the corresponding steady Péclet number is between 10-8/Dm and 10-6/Dm (Dm is the molecular diffusivity with units of cm2/s). Therefore, for Dm⩽10-8cm2/s, the convective transport dominates.

  13. Amino acid-based surfactants – do they deserve more attention?

    Science.gov (United States)

    Bordes, Romain; Holmberg, Krister

    2015-08-01

    The 20 standard amino acids (together with a few more that are not used in the biosynthesis of proteins) constitute a versatile tool box for synthesis of surfactants. Anionic, cationic and zwitterionic amphiphiles can be prepared and surfactants with several functional groups can be obtained by the proper choice of starting amino acid. This review gives examples of procedures used for preparation and discusses important physicochemical properties of the amphiphiles and how these can be taken advantage of for various applications. Micelles with a chiral surface can be obtained by self-assembly of enantiomerically pure surfactants and such supramolecular chirality can be utilized for asymmetric organic synthesis and for preparation of mesoporous materials with chiral pores. Surfactants based on amino acids with two carboxyl groups are effective chelating agents and can be used as collectors in mineral ore flotation. A surfactant based on cysteine readily oxidizes into the corresponding cystine compound, which can be regarded as a gemini surfactant. The facile and reversible cysteine-cystine transformation has been taken advantage of in the design of a switchable surfactant. A very attractive aspect of surfactants based on amino acids is that the polar head-group is entirely natural and that the linkage to the hydrophobic tail, which is often an ester or an amide bond, is easily cleaved. The rate of degradation can be tailored by the structure of the amphiphile. The ester linkage in betaine ester surfactants is particularly susceptible to alkaline hydrolysis and this surfactant type can be used as a biocide with short-lived action. This paper is not intended as a full review on the topic. Instead it highlights concepts that are unique to amino acid-based surfactants and that we believe can have practical implications. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Dipalmitoylphosphatidylcholine is not the major surfactant phospholipid species in all mammals.

    Science.gov (United States)

    Lang, Carol J; Postle, Anthony D; Orgeig, Sandra; Possmayer, Fred; Bernhard, Wolfgang; Panda, Amiya K; Jürgens, Klaus D; Milsom, William K; Nag, Kaushik; Daniels, Christopher B

    2005-11-01

    Pulmonary surfactant, a complex mixture of lipids and proteins, lowers the surface tension in terminal air spaces and is crucial for lung function. Within an animal species, surfactant composition can be influenced by development, disease, respiratory rate, and/or body temperature. Here, we analyzed the composition of surfactant in three heterothermic mammals (dunnart, bat, squirrel), displaying different torpor patterns, to determine: 1) whether increases in surfactant cholesterol (Chol) and phospholipid (PL) saturation occur during long-term torpor in squirrels, as in bats and dunnarts; 2) whether surfactant proteins change during torpor; and 3) whether PL molecular species (molsp) composition is altered. In addition, we analyzed the molsp composition of a further nine mammals (including placental/marsupial and hetero-/homeothermic contrasts) to determine whether phylogeny or thermal behavior determines molsp composition in mammals. We discovered that like bats and dunnarts, surfactant Chol increases during torpor in squirrels. However, changes in PL saturation during torpor may not be universal. Torpor was accompanied by a decrease in surfactant protein A in dunnarts and squirrels, but not in bats, whereas surfactant protein B did not change in any species. Phosphatidylcholine (PC)16:0/16:0 is highly variable between mammals and is not the major PL in the wombat, dunnart, shrew, or Tasmanian devil. An inverse relationship exists between PC16:0/16:0 and two of the major fluidizing components, PC16:0/16:1 and PC16:0/14:0. The PL molsp profile of an animal species is not determined by phylogeny or thermal behavior. We conclude that there is no single PL molsp composition that functions optimally in all mammals; rather, surfactant from each animal is unique and tailored to the biology of that animal.

  15. Respiratory and Systemic Effects of LASSBio596 Plus Surfactant in Experimental Acute Respiratory Distress Syndrome

    Directory of Open Access Journals (Sweden)

    Johnatas Dutra Silva

    2016-02-01

    Full Text Available Background/Aims: Exogenous surfactant has been proposed as adjunctive therapy for acute respiratory distress syndrome (ARDS, but it is inactivated by different factors present in the alveolar space. We hypothesized that co-administration of LASSBio596, a molecule with significant anti-inflammatory properties, and exogenous surfactant could reduce lung inflammation, thus enabling the surfactant to reduce edema and improve lung function, in experimental ARDS. Methods: ARDS was induced by cecal ligation and puncture surgery in BALB/c mice. A sham-operated group was used as control (CTRL. After surgery (6 hours, CTRL and ARDS animals were assigned to receive: (1 sterile saline solution; (2 LASSBio596; (3 exogenous surfactant or (4 LASSBio596 plus exogenous surfactant (n = 22/group. Results: Regardless of exogenous surfactant administration, LASSBio596 improved survival rate and reduced collagen fiber content, total number of cells and neutrophils in PLF and blood, cell apoptosis, protein content in BALF, and urea and creatinine levels. LASSBio596 plus surfactant yielded all of the aforementioned beneficial effects, as well as increased BALF lipid content and reduced surface tension. Conclusion: LASSBio596 exhibited major anti-inflammatory and anti-fibrogenic effects in experimental sepsis-induced ARDS. Its association with surfactant may provide further advantages, potentially by reducing surface tension.

  16. Electronic cigarette vapor alters the lateral structure but not tensiometric properties of calf lung surfactant.

    Science.gov (United States)

    Przybyla, Rebecca J; Wright, Jason; Parthiban, Rajan; Nazemidashtarjandi, Saeed; Kaya, Savas; Farnoud, Amir M

    2017-11-17

    Despite their growing popularity, the potential respiratory toxicity of electronic cigarettes (e-cigarettes) remains largely unknown. One potential aspect of e-cigarette toxicity is the effect of e-cigarette vapor on lung surfactant function. Lung surfactant is a mixture of lipids and proteins that lines the alveolar region. The surfactant layer reduces the surface tension of the alveolar fluid, thereby playing a crucial role in lung stability. Due to their small size, particulates in e-cigarette vapor can penetrate the deep lungs and come into contact with the lung surfactant. The current study sought to examine the potential adverse effects of e-cigarette vapor and conventional cigarette smoke on lung surfactant interfacial properties. Infasurf ® , a clinically used and commercially available calf lung surfactant extract, was used as lung surfactant model. Infasurf ® films were spread on top of an aqueous subphase in a Langmuir trough with smoke particulates from conventional cigarettes or vapor from different flavors of e-cigarettes dispersed in the subphase. Surfactant interfacial properties were measured in real-time upon surface compression while surfactant lateral structure after exposure to smoke or vapor was examined using atomic force microscopy (AFM). E-cigarette vapor regardless of the dose and flavoring of the e-liquid did not affect surfactant interfacial properties. In contrast, smoke from conventional cigarettes had a drastic, dose-dependent effect on Infasurf ® interfacial properties reducing the maximum surface pressure from 65.1 ± 0.2 mN/m to 46.1 ± 1.3 mN/m at the highest dose. Cigarette smoke and e-cigarette vapor both altered surfactant microstructure resulting in an increase in the area of lipid multilayers. Studies with individual smoke components revealed that tar was the smoke component most disruptive to surfactant function. While both e-cigarette vapor and conventional cigarette smoke affect surfactant lateral structure

  17. A Recombinant Fragment of Human Surfactant Protein D Suppresses Basophil Activation and T-Helper Type 2 and B-Cell Responses in Grass Pollen-induced Allergic Inflammation.

    Science.gov (United States)

    Qaseem, Asif S; Singh, Iesha; Pathan, Ansar A; Layhadi, Janice A; Parkin, Rebecca; Alexandra, Fedina; Durham, Stephen R; Kishore, Uday; Shamji, Mohamed H

    2017-12-15

    Recombinant fragment of human surfactant protein D (rfhSP-D) has been shown to suppress house dust mite- and Aspergillus fumigatus-induced allergic inflammation in murine models. We sought to elucidate the effect of rfhSP-D on high-affinity IgE receptor- and CD23-mediated, grass pollen-induced allergic inflammatory responses. rfhSP-D, containing homotrimeric neck and lectin domains, was expressed in Escherichia coli BL21(λDE3)pLysS cells. Peripheral blood mononuclear cells and sera were obtained from individuals with grass pollen allergy (n = 27). The effect of rfhSP-D on basophil activation and histamine release was measured by flow cytometry. IgE-facilitated allergen binding and presentation were assessed by flow cytometry. T-helper cell type 2 (Th2) cytokines were measured in cell culture supernatants. The effect of rfhSP-D on IgE production by B cells when stimulated with CD40L, IL-4, and IL-21 was also determined. rfhSP-D bound to Phleum pratense in a dose- and calcium-dependent manner. Allergen-induced basophil responsiveness and histamine release were inhibited in the presence of rfhSP-D, as measured by CD63, CD203c (P = 0.0086, P = 0.04205), and intracellularly labeled diamine oxidase (P = 0.0003, P = 0.0148). The binding of allergen-IgE complexes to B cells was reduced by 51% (P = 0.002) in the presence of rfhSP-D. This decrease was concomitant with reduction in CD23 expression on B cells (P D suppressed allergen-driven CD27 - CD4 + CRTh2 + T-cell proliferation (P P D inhibited CD40L/IL-4- and IL-21-mediated IgE production (77.12%; P = 0.02) by B cells. For the first time, to our knowledge, we show that rfhSP-D inhibited allergen-induced basophil responses at a single-cell level and suppressed CD23-mediated facilitated allergen presentation and Th2 cytokine production. In addition, rfhSP-D inhibited IgE synthesis by B cells, which is also a novel observation.

  18. Serum concentrations of Krebs von den Lungen-6, surfactant protein D, and matrix metalloproteinase-2 as diagnostic biomarkers in patients with asbestosis and silicosis: a case-control study.

    Science.gov (United States)

    Xue, Changjiang; Wu, Na; Li, Xue; Qiu, Meihua; Du, Xuqin; Ye, Qiao

    2017-11-17

    Asbestosis and silicosis are progressive pneumoconioses characterized by interstitial fibrosis following exposure to asbestos or silica dust. We evaluated the potential diagnostic biomarkers for these diseases. The serum concentrations of Krebs von den Lungen-6 (KL-6), surfactant protein D (SP-D), and matrix metalloproteinase-2 (MMP-2), MMP-7, and MMP-9 were measured in 43 patients with asbestosis, 45 patients with silicosis, 40 dust-exposed workers (DEWs) without pneumoconiosis, and 45 healthy controls (HCs). Chest high-resolution computed tomography (HRCT) images were reviewed by experts blinded to the clinical data. According to the receiver operating characteristic (ROC) curve, the ideal level of each biomarker and its diagnostic sensitivity were obtained. The serum KL-6 and MMP-2 concentrations were highest in patients with asbestosis, particularly in comparison with those in DEWs and HCs (P<0.05). The serum SP-D concentration was significantly higher in patients with asbestosis than in patients with silicosis, DEWs, and HCs (P<0.01), whereas no significant difference was noted among patients with silicosis, DEWs, and HCs. No significant difference in the serum MMP-7 or -9 concentration was found among patients with asbestosis, patients with silicosis, DEWs, or HCs. Among patients with asbestosis, the serum KL-6 concentration was significantly correlated with the lung fibrosis scores on HRCT and negatively correlated with the forced vital capacity (FVC) % predicted and diffusing capacity of the lung for carbon monoxide (DL CO ) % predicted. The serum SP-D and MMP-2 concentrations were negatively correlated with the DL CO % predicted (all P<0.05). The order of diagnostic accuracy according to the ROC curve was KL-6, SP-D, and MMP-2 in patients with asbestosis alone and in the combination of both patients with asbestosis and those with silicosis. The combination of all three biomarkers may increase the possibility of diagnosing asbestosis (sensitivity, 93

  19. Comparative insight into surfactants mediated amyloidogenesis of lysozyme.

    Science.gov (United States)

    Chaturvedi, Sumit K; Khan, Javed M; Siddiqi, Mohammad K; Alam, Parvez; Khan, Rizwan H

    2016-02-01

    Electrostatic and hydrophobic interactions have an important role in the protein aggregation. In this study, we have investigated the effect of charge and hydrophobicity of oppositely charged surfactants i.e., anionic (AOT and SDS) and cationic (CTAB and DTAB) on hen egg white lysozyme at pH 9.0 and 13.0, respectively. We have employed various methods such as turbidity measurements, Rayleigh light scattering, ThT, Congo red and ANS dye binding assays, far-UV CD, atomic force microscopy, transmission electron and fluorescence microscopy. At lower molar ratio, both anionic and cationic surfactants promote amyloid fibril formation in lysozyme at pH 9.0 and 13.0, respectively. The aggregation was proportionally increased with respect to protein concentration and hydrophobicity of surfactant. The morphology of aggregates at both the pH was fibrillar in structure, as visualized by dye binding and microscopic imaging techniques. Initially, the interaction between surfactants and lysozyme was electrostatic and then hydrophobic as investigated by ITC. This study demonstrates the crucial role of charge and hydrophobicity during amyloid fibril formation. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Fungal growth on anion surfactant medium.

    Science.gov (United States)

    Hamada, Nobuo; Abe, Niichiro

    2009-12-01

    Before the present study, no fungi using anion surfactant as a nutrient had been identified, although some fungi were known to use nonion surfactant. Washing water collected from 63 washing machines was inoculated onto 0.1% LAS (Sodium dodecyl benzenesulfonate) anion surfactant media to identify fungi that can feed on anion-surfactant. Small dark colonies of fungi were found on several of the Petri-dishes from 12 days after inoculation. These were identified as Cladophialophora boppii and Exophiala spinifera using morphological features and rDNA data. A number of the isolates of C. boppii specifically were recognized as using anion surfactant as a nutrient. The growth characteristics of the two fungal species were examined on surfactant media of three kinds. Apart from anion surfactant, the fungi were also able to grow on nonion surfactant and on soap. The application of these fungi for environmental cleansing after detergent pollution is also discussed.

  1. Synthesis of carbohydrate-based surfactants

    Science.gov (United States)

    Pemberton, Jeanne E.; Polt, Robin L.; Maier, Raina M.

    2016-11-22

    The present invention provides carbohydrate-based surfactants and methods for producing the same. Methods for producing carbohydrate-based surfactants include using a glycosylation promoter to link a carbohydrate or its derivative to a hydrophobic compound.

  2. Surfactant Therapy of ALI and ARDS

    OpenAIRE

    Raghavendran, K; Willson, D; Notter, RH

    2011-01-01

    This article examines exogenous lung surfactant replacement therapy and its utility in mitigating clinical acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Biophysical research has documented that lung surfactant dysfunction can be reversed or mitigated by increasing surfactant concentration, and multiple studies in animals with ALI/ARDS have shown that respiratory function and pulmonary mechanics in vivo can be improved by exogenous surfactant administration. Exoge...

  3. Cationic surfactants as the hydrolytic micellar catalysts

    OpenAIRE

    Janošcová, Petra

    2013-01-01

    Cationic surfactants as the hydrolytic micellar catalysts Petra Janošcová The effectiveness of hydrolytic cleavage of the pesticide fenitrothionin cationic surfactants micellar media has been tested. All used surfactants increased the rate of fenitrothionhydrolysis, which was the evidence of micellar catalysis. For some surfactants decreases has been evident at the highest rate of hydrolysis concentrations. It has been the result of a phenomenon called the effect of empty micelles. High hydro...

  4. Stabilizing two IgG1 monoclonal antibodies by surfactants: Balance between aggregation prevention and structure perturbation.

    Science.gov (United States)

    Wang, Shujing; Wu, Guoliang; Zhang, Xinyi; Tian, Zhou; Zhang, Ning; Hu, Tao; Dai, Weiguo; Qian, Feng

    2017-05-01

    Surfactants are widely used as stabilizers in the biopharmaceutical formulations to minimize protein aggregation. Under a fixed stress condition, the protecting and destabilizing effects of surfactants are hypothesized to be highly dependent on the species and concentrations of surfactants and mAb. Therefore, we here studied the aggregation-prevention and structure-perturbation effects of eight commonly used surfactants (Tw20, Tw80, Brij35, Chaps, TrX-100, SDS, Pluronic F68 and F127) on two IgG1 solution formulations under agitation, using analytical methodologies including visual inspection, OD 350 measurement, HPLC-SEC, circular dicroism, fluorescence spectroscopy and differential scanning calorimetry. We found that: (1) With concentrations range from 0.02 to 2mg/mL, nonionic surfactants were found to offer efficient aggregation-prevention effect, which is superior than the ionic surfactants; and higher surfactant concentration prevented mAb aggregation better especially under prolonged stability test under stress conditions. (2) The surfactant induced structure-perturbation emerged when even higher surfactant concentration (≥2mg/mL) was used, and such effect was surfactant-property dependent; and (3) the two IgG1 demonstrated different aggregation mechanisms and surfactant dependency, especially at high mAb concentrations. In conclusion, surfactants usage in mAb formulations, including the types and concentrations, should strike an optimal balance between the desirable aggregation-prevention and the detrimental structure-perturbation effects, while the consideration of mAb aggregation mechanism and concentration is also required for surfactant assessment. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Respiratory failure following anti-lung serum: study on mechanisms associated with surfactant system damage

    International Nuclear Information System (INIS)

    Lachmann, B.; Hallman, M.; Bergmann, K.C.

    1987-01-01

    Within 2 minutes intravenous anti-lung serum (ALS) into guinea pig induces a respiratory failure that is fatal within 30 min. The relationship between surfactant, alveolar-capillary permeability and respiratory failure was studied. Within two minutes ALS induced a leak in the alveolar-capillary barrier. Within 30 minutes 28.3% (controls, given normal rabbit serum: 0.7%) of iv 131 I-albumin, and 0.5% (controls 0.02%) of iv surfactant phospholipid tracer were recovered in bronchoalveolar lavage. Furthermore, 57% (controls 32%) of the endotracheally administered surfactant phospholipid became associated with lung tissue and only less than 0.5% left the lung. The distribution of proteins and phospholipids between the in vivo small volume bronchoalveolar lavages and the ex vivo bronchoalveolar lavages were dissimilar: 84% (controls 20%) of intravenously injected, lavageable 131 I-albumin and 23% (controls 18%) of total lavageable phospholipid were recovered in the in vivo small volume bronchoalveolar lavages. ALS also decreased lavageable surfactant phospholipid by 41%. After ALS the minimum surface tension increased. The supernatant of the lavage increased the minimum surface tension of normal surfactant. In addition, the sediment fraction of the lavage had slow surface adsorption, and a marked reduction in 35,000 and 10,000 MW peptides. Exogenous surfactant ameliorated the ALS-induced respiratory failure. We propose that inhibition, altered intrapulmonary distribution, and dissociation of protein and phospholipid components of surfactant are important in early pathogenesis of acute respiratory failure

  6. Binding of cationic surfactants to humic substances

    NARCIS (Netherlands)

    Ishiguro, M.; Tan, W.; Koopal, L.K.

    2007-01-01

    Commercial surfactants are introduced into the environment either through waste products or site-specific contamination. The amphiphilic nature of both surfactants and humic substances (HS) leads to their mutual attraction especially when surfactant and HS are oppositely charged. Binding of the

  7. Surfactant adsorption to soil components and soils

    NARCIS (Netherlands)

    Ishiguro, Munehide; Koopal, Luuk K.

    2016-01-01

    Soils are complex and widely varying mixtures of organic matter and inorganic materials; adsorption of surfactants to soils is therefore related to the soil composition. We first discuss the properties of surfactants, including the critical micelle concentration (CMC) and surfactant adsorption on

  8. Membrane-surfactant interactions. The role of surfactant in mitochondrial complex III-phospholipid-Triton X-100 mixed micelles

    International Nuclear Information System (INIS)

    Valpuesta, J.M.; Arrondo, J.L.; Barbero, M.C.; Pons, M.; Goni, F.M.

    1986-01-01

    Complex III (ubiquinol-cytochrome c reductase) was purified from beef heart mitochondria in the form of protein-phospholipid-Triton X-100 mixed micelles (about 1:80:100 molar ratio). Detergent may be totally removed by sucrose density gradient centrifugation, and the resulting lipoprotein complexes retain full enzyme activity. In order to understand the role of surfactant in the mixed micelles, and the interaction of Triton X-100 with integral membrane proteins and phospholipid bilayers, both the protein-lipid-surfactant mixed micelles and the detergent-free lipoprotein system were examined from the point of view of particle size and ultrastructure, enzyme activity, tryptophan fluorescence quenching, 31P NMR, and Fourier transform infrared spectroscopy. The NMR and IR spectroscopic studies show that surfactant withdrawal induces a profound change in phospholipid architecture, from a micellar to a lamellar-like phase. However, electron microscopic observations fail to reveal the existence of lipid bilayers in the absence of detergent. We suggest that, under these conditions, the lipid:protein molar ratio (80:1) is too low to permit the formation of lipid bilayer planes, but the relative orientation and mobility of phospholipids with respect to proteins is similar to that of the lamellar phase. Protein conformational changes are also detected as a consequence of surfactant removal. Fourier transform infrared spectroscopy indicates an increase of peptide beta-structure in the absence of Triton X-100; changes in the amide II/amide I intensity ratio are also detected, although the precise meaning of these observations is unclear

  9. Persurf, a new method to improve surfactant delivery: a study in surfactant depleted rats.

    Directory of Open Access Journals (Sweden)

    Wolfram Burkhardt

    Full Text Available PURPOSE: Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf and to test in surfactant depleted Wistar rats whether Persurf achieves I. a more homogenous pulmonary distribution and II. a more homogenous recruitment of alveoli when compared with surfactant or PFC alone. METHODS: Three different PFC were mixed with surfactant and phospholipid concentration in the emulsion was measured. After surfactant depletion, animals either received 30 ml/kg of PF5080, 100 mg/kg of stained (green dye Curosurf™ or 30 ml/kg of Persurf. Lungs were fixated after 1 hour of ventilation and alveolar aeration and surfactant distribution was estimated by a stereological approach. RESULTS: Persurf contained 3 mg/ml phospholipids and was stable for more than 48 hours. Persurf-administration improved oxygenation. Histological evaluation revealed a more homogenous surfactant distribution and alveolar inflation when compared with surfactant treated animals. CONCLUSIONS: In surfactant depleted rats administration of PFC-in-surfactant emulsion leads to a more homogenous distribution and aeration of the lung than surfactant alone.

  10. Study on the surfactants present in atmospheric aerosols collected in the Okinawa Japan

    Science.gov (United States)

    Kamegawa, A.; Kasaba, T.; Shimabukuro, W.; Arakaki, T.

    2017-12-01

    The main constituent of atmospheric aerosols is organic substances, which occupy 20 to 70% of the mass. Organic matters in the aerosols contain organic acids, protein and humic acid, which behave similar to surfactants. Since surfactants contain both hydrophobic and hydrophilic functional groups in the molecule, they can play important roles in cloud formation and can affect climate change, but detailed mechanisms and magnitude are not well understood. In addition, surfactants can cause asthma, allergy, dry eye and so on. In this study, our aim is to characterize surfactants in the aerosols collected in different seasons in Okinawa, Japan. Atmospheric aerosols were collected at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) during Sep. 2013 and July 2014. Surfactants in the environment are comprised of artificially synthesized compounds and naturally derived organics so we only differentiate them into anionic and cationic surfactants. Colorimetric methods were used to determine the concentrations of anionic surfactants as methylene blue active substance (MBAS). Cationic surfactants were also measured by colorimetric method as disulfine blue active substance (DBAS) and showed always below detection limit. Thus, we only discuss anionic surfactants measured as MBAS. Water soluble organic carbon (WSOC) and metal concentrations were also measured for the same aerosol samples. Concentrations of MBAS in the studied samples were 2-3 times higher in spring, fall and winter than those collected in summer. MBAS concentration in the aerosols showed strong correlation with sulfate ion and WSOC, and slightly weaker correlation with nss-sulfate ion. Among the metals, only sodium ion showed a relatively strong correlation with MBAS concentrations. It is suggested that the anionic surfactants in the studied aerosols are mainly derived from marine sources.

  11. Spectroscopy and computational studies on the interaction of octyl, dodecyl, and hexadecyl derivatives of anionic and cationic surfactants with adenosine deaminase.

    Science.gov (United States)

    Ajloo, Davood; Mahmoodabadi, Najmeh; Ghadamgahi, Maryam; Saboury, Ali Akbar

    2016-07-01

    Effects of sodium (octyl, dodecyl, hexadecyl) sulfate and their cationic analogous on the structure of adenosine deaminase (ADA) were investigated by fluorescence and circular dichroism spectroscopy as well as molecular dynamics simulation and docking calculation. Root-mean-square derivations, radius of gyration, solvent accessible surface area, and radial distribution function were obtained. The results showed that anionic and cationic surfactants reduce protein stability. Cationic surfactants have more effect on the ADA structure in comparison with anionic surfactants. More concentration and longer surfactants are parallel to higher denaturation. Furthermore, aggregation in the presence of anionic surfactants is more than cationic surfactants. Docking data showed that longer surfactants have more interaction energy and smaller ones bound to the active site.

  12. Calcium-tolerant anionic surfactants

    NARCIS (Netherlands)

    Kooreman, Alexander

    1995-01-01

    One of the problems of applying anionic surfactants in, for example, laundry detergents is the precipitation of calcium salts. Much effort has been directed towards avoiding precipitation. There are at least three ways for tackling the problem. The first involves the use of a large quantity of

  13. Surfactant -- Where Are We in 2003?

    Directory of Open Access Journals (Sweden)

    JF Lewis

    2004-01-01

    Full Text Available Surfactant research has progressed over the past several years to the extent that exogenous surfactant administration in patients with the acute respiratory distress syndrome (ARDS is now being evaluated. Unfortunately, clinical responses have been variable, and we now need to take a look at how surfactant is altered in this disease so that more effective treatment strategies can be developed. This review briefly discusses the biophysical and host defense properties of surfactant, the impact of mechanical ventilation (MV on the endogenous surfactant system and the most recent clinical data involving exogenous surfactant administration in patients with ARDS. Discussions regarding future directions of surfactant research both in ARDS and diseases other than acute lung injury are included.

  14. Composition, structure and mechanical properties define performance of pulmonary surfactant membranes and films

    DEFF Research Database (Denmark)

    Ortiz, Elisa Parra; Perez-Gil, Jesús

    2015-01-01

    The respiratory surface in the mammalian lung is stabilized by pulmonary surfactant, a membrane-based system composed of multiple lipids and specific proteins, the primary function of which is to minimize the surface tension at the alveolar air-liquid interface, optimizing the mechanics of breath......The respiratory surface in the mammalian lung is stabilized by pulmonary surfactant, a membrane-based system composed of multiple lipids and specific proteins, the primary function of which is to minimize the surface tension at the alveolar air-liquid interface, optimizing the mechanics...... of breathing and avoiding alveolar collapse, especially at the end of expiration. The goal of the present review is to summarize current knowledge regarding the structure, lipid-protein interactions and mechanical features of surfactant membranes and films and how these properties correlate with surfactant...... biological function inside the lungs. Surfactant mechanical properties can be severely compromised by different agents, which lead to surfactant inhibition and ultimately contributes to the development of pulmonary disorders and pathologies in newborns, children and adults. A detailed comprehension...

  15. Cholesterol rules: direct observation of the coexistence of two fluid phases in native pulmonary surfactant membranes at physiological temperatures

    DEFF Research Database (Denmark)

    Bernardino de la Serna, Jorge; Perez-Gil, Jesus; Simonsen, Adam C

    2004-01-01

    Pulmonary surfactant, the lipid-protein material that stabilizes the respiratory surface of the lungs, contains approximately equimolar amounts of saturated and unsaturated phospholipid species and significant proportions of cholesterol. Such lipid composition suggests that the membranes taking p...

  16. Adsorption of dimeric surfactants in lamellar silicates

    Energy Technology Data Exchange (ETDEWEB)

    Balcerzak, Mateusz; Pietralik, Zuzanna [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Domka, Ludwik [Department of Metalorganic Chemistry, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań (Poland); Skrzypczak, Andrzej [Institute of Chemical Technology, Poznań University of Technology, Berdychowo 4, 60-965 Poznań (Poland); Kozak, Maciej, E-mail: mkozak@amu.edu.pl [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2015-12-01

    Highlights: • The intercalation of dimeric surfactants changed the morphology of MMT samples. • XRD indicated structures formed by surfactant molecules in interlayer space. • The four-step thermal decomposition of dimeric surfactant, confirms intercalation. - Abstract: The adsorption of different types of cationic surfactants in lamellar silicates changes their surface character from hydrophilic to hydrophobic. This study was undertaken to obtain lamellar silicates modified by a series of novel dimeric (gemini) surfactants of different length alkyl chains and to characterise these organophilised materials. Synthetic sodium montmorillonite SOMASIF® ME 100 (M) and enriched bentonite of natural origin (Nanoclay – hydrophilic bentonite®) were organophilised with dimeric (gemini) surfactants (1,1′-(1,4-butanediyl)bis(alkoxymethyl)imidazolium dichlorides). As a result of surfactant molecule adsorption in interlamellar space, the d-spacing (d{sub 001}) increased from 0.97 nm (for the anhydrous structure) to 2.04 nm. A Fourier transform infrared spectroscopy (FTIR) analysis of the modified systems reveals bands assigned to the stretching vibrations of the CH{sub 2} and CH{sub 3} groups and the scissoring vibrations of the NH group from the structure of the dimeric surfactants. Thermogravimetric (TG) and derivative thermogravimetric (DTG) studies imply a four-stage process of surfactant decomposition. Scanning electron microscopy (SEM) images provide information on the influence of dimeric surfactant intercalation into the silicate structures. Particles of the modified systems show a tendency toward the formation of irregularly shaped agglomerates.

  17. A conservative SPH method for surfactant dynamics

    Science.gov (United States)

    Adami, S.; Hu, X. Y.; Adams, N. A.

    2010-03-01

    In this paper, a Lagrangian particle method is proposed for the simulation of multiphase flows with surfactant. The model is based on the multiphase smoothed particle hydrodynamics (SPH) framework of Hu and Adams (2006) [1]. Surface-active agents (surfactants) are incorporated into our method by a scalar quantity describing the local concentration of molecules in the bulk phase and on the interface. The surfactant dynamics are written in conservative form, thus global mass of surfactant is conserved exactly. The transport model of the surfactant accounts for advection and diffusion. Within our method, we can simulate insoluble surfactant on an arbitrary interface geometry as well as interfacial transport such as adsorption or desorption. The flow-field dynamics and the surfactant dynamics are coupled through a constitutive equation, which relates the local surfactant concentration to the local surface-tension coefficient. Hence, the surface-tension model includes capillary and Marangoni-forces. The present numerical method is validated by comparison with analytic solutions for diffusion and for surfactant dynamics. More complex simulations of an oscillating bubble, the bubble deformation in a shear flow, and of a Marangoni-force driven bubble show the capabilities of our method to simulate interfacial flows with surfactants.

  18. Surfactants in tribology, v.3

    CERN Document Server

    Biresaw, Girma

    2013-01-01

    The manufacture and use of almost every consumer and industrial product rely on application of advanced knowledge in surface science and tribology. These two disciplines are of critical importance in major economic sectors, such as mining, agriculture, manufacturing (including metals, plastics, wood, computers, MEMS, NEMS, appliances), construction, transportation, and medical instruments, transplants, and diagnostic devices. An up-to-date reference with contributions by experts in surface science and tribology, Surfactants in Tribology, Volume 3 discusses some of the underlying tribological a

  19. Enhanced Oil Recovery with Surfactant Flooding

    DEFF Research Database (Denmark)

    Sandersen, Sara Bülow

    Enhanced oil recovery (EOR) is being increasingly applied in the oil industry and several different technologies have emerged during, the last decades in order to optimize oil recovery after conventional recovery methods have been applied. Surfactant flooding is an EOR technique in which the phase...... behavior inside the reservoir can be manipulated by the injection of surfactants and co-surfactants, creating advantageous conditions in order to mobilize trapped oil. Correctly designed surfactant systems together with the crude oil can create microemulsions at the interface between crude oil and water......, thus reducing the interfacial tension (IFT) to ultra low (0.001 mN/m), which consequently will mobilize the residual oil and result in improved oil recovery. This EOR technology is, however, made challenging by a number of factors, such as the adsorption of surfactant and co-surfactant to the rock...

  20. Acute Pathophysiological Effects of Intratracheal Instillation of Budesonide and Exogenous Surfactant in a Neonatal Surfactant-depleted Piglet Model

    Directory of Open Access Journals (Sweden)

    Chia-Feng Yang

    2010-08-01

    Conclusions: Intratracheal instillation of surfactant or surfactant plus budesonide can improve oxygenation and pulmonary histologic outcome in neonatal surfactant-depleted lungs. The additional use of budesonide does not disturb the function of the exogenous surfactant. Intratracheal administration of a corticosteroid combined with surfactant may be an effective method for alleviating local pulmonary inflammation in severe RDS.

  1. Surfactant-enhanced cellulose nanocrystal Pickering emulsions.

    Science.gov (United States)

    Hu, Zhen; Ballinger, Sarah; Pelton, Robert; Cranston, Emily D

    2015-02-01

    The effect of surfactants on the properties of Pickering emulsions stabilized by cellulose nanocrystals (CNCs) was investigated. Electrophoretic mobility, interfacial tension, confocal microscopy and three-phase contact angle measurements were used to elucidate the interactions between anionic CNCs and cationic alkyl ammonium surfactants didecyldimethylammonium bromide (DMAB) and cetyltrimethylammonium bromide (CTAB). Both surfactants were found to adsorb onto CNCs with concentration-dependent morphology. At low concentrations, individual surfactant molecules adsorbed with alkyl tails pointing outward leading to hydrophobic CNCs. At higher concentrations, above the surfactant's apparent critical micelle concentration, surfactant aggregate morphologies on CNCs were inferred and the hydrophobicity of CNCs decreased. DMAB, which has two alkyl tails, rendered the CNCs more hydrophobic than CTAB which has only a single alkyl tail, at all surfactant concentrations. The change in CNC wettability from surfactant adsorption was directly linked to emulsion properties; adding surfactant increased the emulsion stability, decreased the droplet size, and controlled the internal phase of CNC Pickering emulsions. More specifically, a double transitional phase inversion, from oil-in-water to water-in-oil and back to oil-in-water, was observed for emulsions with CNCs and increasing amounts of DMAB (the more hydrophobic surfactant). With CNCs and CTAB, no phase inversion was induced. This work represents the first report of CNC Pickering emulsions with surfactants as well as the first CNC Pickering emulsions that can be phase inverted. The ability to surface modify CNCs in situ and tailor emulsions by adding surfactants may extend the potential of CNCs to new liquid formulations and extruded/spray-dried materials. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Interactions between surfactants and hydrolytic enzymes.

    Science.gov (United States)

    Holmberg, Krister

    2017-12-05

    Hydrolytic enzymes are combined with surfactants in many types of formulations, for instance detergents and personal care products. If the surfactant interacts with the enzyme there may be conformational changes that eventually lead to loss of the enzymatic activity. From a practical point of view it is important to understand the nature and magnitude of these interactions. After an introduction of the topic the review briefly discusses enzyme catalyzed reactions where surfactants are substrates for the enzyme. The rest of the review relates to associations between surfactants and hydrolytic enzymes without the surfactant being a substrate in the reaction. A discussion about general principles for such interactions is followed by a survey of the relevant literature related to four important types of hydrolytic enzymes: lipases, proteases, amylases and cellulases. It is shown in the review that the effect exerted by the surfactant differs between the different types of enzymes; it is therefore difficult to make general statements about which surfactants are most detrimental to the activity of hydrolytic enzymes. However, as a general rule nonionic surfactants can be regarded as more benign to an enzyme than anionic and cationic surfactants. This difference can be ascribed to the difference in binding mode. Whereas a nonionic surfactant only binds to the enzyme through hydrophobic interactions, an ionic surfactant can bind by a combination of electrostatic attraction and hydrophobic interaction. This latter type of binding can be strong and lead to conformational changes already at very low surfactant concentration, often far below its critical micelle concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. A study on the interaction of horse heart cytochrome c with some conventional and ionic liquid surfactants probed by ultraviolet-visible and fluorescence spectroscopic techniques.

    Science.gov (United States)

    Mondal, Satyajit; Das, Bijan

    2018-06-05

    The interactions of a protein cytochrome c with some selected conventional and ionic liquid surfactants have been investigated at pH7.4 using ultraviolet-visible and fluorescence spectroscopic techniques. We used four conventional surfactants - cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), sodium N-dodecanoylsarcosinate (SDDS), and N-decanoyl-N-methylglucamine (Mega 10), and a surface active ionic liquid 1-hexadecyl-3-methylimidazolium chloride (C 16 MeImCl). All the investigated surfactants were found to induce an unfolding of the protein cytochrome c. In presence of CTAB, SDDS and C 16 MeImCl, the heme iron atom was found to loose methionine from its axial position. Differential binding of the surfactant monomers and their micelles to the protein molecules was inferred. The ionic surfactants were found to be more effective than the nonionic one in unfolding the investigated protein. However, the extent of binding of CTAB/C 16 MeImCl to cytochrome c reaches a plateau past the critical micellization concentration (cmc) of the surfactant. For each of the cytochrome c-DTAB, cytochrome c-SDDS and cytochrome c-Mega 10 system, although there exists an inflection in the surfactant-binding, saturation point could not be detected. It has been demonstrated from the ultraviolet-visible spectral studies that the oxidation state of iron in cytochrome c does not change when the protein binds with the investigated surfactants. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Phase transitions in surfactant monolayers

    International Nuclear Information System (INIS)

    Casson, B.D.

    1998-01-01

    Two-dimensional phase transitions have been studied in surfactant monolayers at the air/water interface by sum-frequency spectroscopy and ellipsometry. In equilibrium monolayers of medium-chain alcohols C n H 2n+1 OH (n = 9-14) a transition from a two-dimensional crystalline phase to a liquid was observed at temperatures above the bulk melting point. The small population of gauche defects in the solid phase increased only slightly at the phase transition. A model of the hydrocarbon chains as freely rotating rigid rods allowed the area per molecule and chain tilt in the liquid phase to be determined. The area per molecule, chain tilt and density of the liquid phase all increased with increasing chain length, but for each chain length the density was higher than in a bulk liquid hydrocarbon. In a monolayer of decanol adsorbed at the air/water interface a transition from a two-dimensional liquid to a gas was observed. A clear discontinuity in the coefficient of ellipticity as a function of temperature showed that the transition is first-order. This result suggests that liquid-gas phase transitions in surfactant monolayers may be more widespread than once thought. A solid-liquid phase transition has also been studied in mixed monolayers of dodecanol with an anionic surfactant (sodium dodecyl sulphate) and with a homologous series of cationic surfactants (alkyltrimethylammonium bromides: C n TABs, n = 12, 14, 16). The composition and structure of the mixed monolayers was studied above and below the phase transition. At low temperatures the mixed monolayers were as densely packed as a monolayer of pure dodecanol in its solid phase. At a fixed temperature the monolayers under-went a first-order phase transition to form a phase that was less dense and more conformationally disordered. The proportion of ionic surfactant in the mixed monolayer was greatest in the high temperature phase. As the chain length of the C n TAB increased the number of conformational defects

  5. Surfactant nebulisation : lung function, surfactant distribution and pulmonary blood flow distribution in lung lavaged rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1997-01-01

    Objective: Surfactant nebulisation is a promising alternative to surfactant instillation in newborns with the respiratory distress syndrome. Although less surfactant is deposited in the lung, it improves gas exchange, probably due to a superior distribution. We hypothesize that a more uniform

  6. Solubilization of Hydrophobic Dyes in Surfactant Solutions

    Directory of Open Access Journals (Sweden)

    Ali Reza Tehrani-Bagha

    2013-02-01

    Full Text Available In this paper, the use of surfactants for solubilization of hydrophobic organic dyes (mainly solvent and disperse dyes has been reviewed. The effect of parameters such as the chemical structures of the surfactant and the dye, addition of salt and of polyelectrolytes, pH, and temperature on dye solubilization has been discussed. Surfactant self-assemble into micelles in aqueous solution and below the concentration where this occurs—the critical micelle concentration (CMC—there is no solubilization. Above the CMC, the amount of solubilized dye increases linearly with the increase in surfactant concentration. It is demonstrated that different surfactants work best for different dyes. In general, nonionic surfactants have higher solubilization power than anionic and cationic surfactants. It is likely that the reason for the good performance of nonionic surfactants is that they allow dyes to be accommodated not only in the inner, hydrocarbon part of the micelle but also in the headgroup shell. It is demonstrated that the location of a dye in a surfactant micelle can be assessed from the absorption spectrum of the dye-containing micellar solution.

  7. Remediation using trace element humate surfactant

    Science.gov (United States)

    Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

    2016-08-30

    A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

  8. Lung preservation in experimental ischemia/reperfusion injury and lung transplantation: a comparison of natural and synthetic surfactants.

    Science.gov (United States)

    Knudsen, Lars; Boxler, Laura; Mühlfeld, Christian; Schaefer, Inga-Marie; Becker, Laura; Bussinger, Christine; von Stietencron, Immanuel; Madershahian, Navid; Richter, Joachim; Wahlers, Thorsten; Wittwer, Thorsten; Ochs, Matthias

    2012-01-01

    Surfactant inactivation results from ischemia/reperfusion injury and plays a major role in the pathogenesis of primary graft dysfunction after clinical lung transplantation. Thus, prophylactic administration of exogenous surfactant preparations before the onset of ischemia/reperfusion has proven to be effective in preserving pulmonary structure and function. Various natural and synthetic surfactant preparations exhibit differences regarding the biochemical composition and biophysical properties. In this study we compared the efficacy of preservation of pulmonary structure and function of the natural surfactant preparations Curosurf and Survanta to that of a synthetic surfactant containing an analog of surfactant protein C (SPC-33) in a rat model of ischemia/reperfusion injury. The oxygenation capacity and peak inspiratory pressure during the reperfusion period were recorded. By applying design-based stereology at the light- and electron-microscopic level, pathologic alterations, including alveolar edema, injury of the blood-air barrier and the intra-alveolar as well as intracellular surfactant pools, were quantified. The best oxygenation and preservation of lung structure was achieved with Curosurf. Survanta treatment was associated with the most severe injury of the blood-air barrier, and SPC-33 demonstrated signs of microatelectasis. The intra-alveolar surfactant pool after Curosurf and SPC-33 was dominated by active surfactant subtypes, whereas Survanta was associated with the highest fraction of inactive surfactant. The intracellular surfactant pool did not show any differences between the treatment groups. Taken together, Curosurf achieved the best structural and functional lung preservation, whereas Survanta was inferior to both Curosurf and SPC-33. Copyright © 2012 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  9. Effects of soluble surfactants on the deformation and breakup of stretching liquid bridges.

    Science.gov (United States)

    Liao, Ying-Chih; Subramani, Hariprasad J; Franses, Elias I; Basaran, Osman A

    2004-11-09

    Surfactants are routinely used to control the breakup of drops and jets in many applications such as inkjet printing, crop spraying, and DNA or protein microarraying. The breakup of surfactant-free drops and jets has been extensively studied. By contrast, little is known about the closely related problem of interface rupture when surfactants are present. Solutions of a nonionic surfactant, pentaethylene glycol monododecyl ether, or C12E5, in water and in 90 wt % glycerol/water are used to show the effects of surfactant and viscosity on the deformation and breakup dynamics of stretching liquid bridges. Equilibrium surface tensions for both solutions can be fitted with the Langmuir-Szyskowski equation. All experiments have been done at 24 degrees C. The critical micelle concentrations for C12E5 are 0.04 and 0.4 mM in water and the glycerol/water solution, respectively. With high-speed imaging, the dynamic shapes of bridges held captive between two rods of 3.15 mm diameter are captured and analyzed with a time resolution of 0.1-1 ms. The bridge lengths are 3.15 mm initially and about 5-7 mm at pinch-off. Breakup occurs after stretching for about 0.2-0.3 s, depending on the solution viscosity and the surfactant concentration. When the liquid bridges break up, the volume of the sessile drop left on the bottom rod is about 3 times larger than that of the pendant drop left on the top rod. This asymmetry is due to gravity and is influenced by the equilibrium surface tensions. Surfactant-containing low-viscosity water bridges are shown to break up faster than surfactant-free ones because of the effect of gravity. With or without surfactant, water bridges form satellite drops. Surfactant-containing high-viscosity glycerol/water bridges break up more slowly than surfactant-free ones because of strong viscous effects. Moreover, the shapes of the sessile drops close to breakup exhibit a "pear-like" tip; whether a satellite forms depends on the surface age of the bridge before

  10. Hemolysis by surfactants--A review.

    Science.gov (United States)

    Manaargadoo-Catin, Magalie; Ali-Cherif, Anaïs; Pougnas, Jean-Luc; Perrin, Catherine

    2016-02-01

    An overview of the use of surfactants for erythrocyte lysis and their cell membrane action mechanisms is given. Erythrocyte membrane characteristics and its association with the cell cytoskeleton are presented in order to complete understanding of the erythrocyte membrane distortion. Cell homeostasis disturbances caused by surfactants might induce changes starting from shape modification to cell lysis. Two main mechanisms are hypothesized in literature which are osmotic lysis and lysis by solubilization even if the boundary between them is not clearly defined. Another specific mechanism based on the formation of membrane pores is suggested in the particular case of saponins. The lytic potency of a surfactant is related to its affinity for the membrane and the modification of the lipid membrane curvature. This is to be related to the surfactant shape defined by its hydrophobic and hydrophilic moieties but also by experimental conditions. As a consequence, prediction of the hemolytic potency of a given surfactant is challenging. Several studies are focused on the relation between surfactant erythrolytic potency and their physico-chemical parameters such as the critical micellar concentration (CMC), the hydrophile-lipophile balance (HLB), the surfactant membrane/water partition coefficient (K) or the packing parameter (P). The CMC is one of the most important factors considered even if a lytic activity cut-off effect points out that the only consideration of CMC not enough predictive. The relation K.CMC must be considered in addition to the CMC to predict the surfactant lytic capacity within the same family of non ionic surfactant. Those surfactant structure/lytic activity studies demonstrate the requirement to take into account a combination of physico-chemical parameters to understand and foresee surfactant lytic potency. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. The influence of lung surfactant liquid crystalline nanostructures on respiratory drug delivery.

    Science.gov (United States)

    Das, Shyamal C; Stewart, Peter J

    2016-12-05

    The respiratory route increasingly has been used for both local and systemic drug delivery. Although drug is absorbed rapidly after respiratory delivery, the role of lung surfactant in drug delivery is not well understood. The human lung contains only around 15mL of surface lining fluid spread over ∼100m 2 surface. The fluid contains lung surfactant at a concentration of 8-24mg/kg/body weight; the lung surfactant which is lipo-protein in nature can form different liquid crystalline nanostructures. After a brief overview of the anatomy of respiratory system, the review has focused on the current understanding of lung surface lining fluid, lung surfactants and their composition and possible self-assembled nanostructures. The role of lung surfactant in drug delivery and drug dissolution has been briefly considered. Lung surfactant may form different liquid crystalline phases which can have an active role in drug delivery. The hypotheses developed in this review focuses on the potential roles of surface epithelial fluid containing liquid crystalline nanostructures in defining the dissolution mechanism and rate. The hypotheses also focus an understanding how liquid crystalline nanostructures can be used to control dissolution rate and how the nanostructures might be changed to influence delivery and induce toxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2003-07-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior, interfacial tension (IFT) and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil-wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate-wet for many surfactants and water-wet for one surfactant. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting core adsorption, phase behavior, wettability and mobilization studies.

  13. of surfactant replacement therapy at Johannesburg Hospital ...

    African Journals Online (AJOL)

    Objective. To assess the impact of surfactant replacement therapy (SRl) on the outcome of hyaline membrane disease (HMD) and to assess the cost implications of a policy of selective administration of artificial surfactant. Design. The short-term outcome of 103 newborns ventilated for HMD (61 selected for SRT according to ...

  14. Surfactant effects on soil aggregate tensile strength

    Science.gov (United States)

    Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

  15. Measuring surfactant concentration in plating solutions

    Science.gov (United States)

    Bonivert, William D.; Farmer, Joseph C.; Hachman, John T.

    1989-01-01

    An arrangement for measuring the concentration of surfactants in a electrolyte containing metal ions includes applying a DC bias voltage and a modulated voltage to a counter electrode. The phase angle between the modulated voltage and the current response to the modulated voltage at a working electrode is correlated to the surfactant concentration.

  16. Surfactant Adsorption: A Revised Physical Chemistry Lab

    Science.gov (United States)

    Bresler, Marc R.; Hagen, John P.

    2008-01-01

    Many physical chemistry lab courses include an experiment in which students measure surface tension as a function of surfactant concentration. In the traditional experiment, the data are fit to the Gibbs isotherm to determine the molar area for the surfactant, and the critical micelle concentration is used to calculate the Gibbs energy of micelle…

  17. Surfactants and submicron sea spray generation

    NARCIS (Netherlands)

    Sellegri, K.; O'Dowd, C.D.; Yoon, Y.J.; Jennings, S.G.; Leeuw, G. de

    2006-01-01

    Laboratory experiments have been carried out to elucidate the role of surfactants on the primary marine aerosol production of submicron marine aerosols. A synthetic surfactant SDS was used in conjunction with artificially generated seawater, and the resultant bubble-mediated aerosol produced was

  18. The adsorption of biomolecules to multi-walled carbon nanotubes is influenced by both pulmonary surfactant lipids and surface chemistry

    Directory of Open Access Journals (Sweden)

    Yan Bing

    2010-12-01

    Full Text Available Abstract Background During production and processing of multi-walled carbon nanotubes (MWCNTs, they may be inhaled and may enter the pulmonary circulation. It is essential that interactions with involved body fluids like the pulmonary surfactant, the blood and others are investigated, particularly as these interactions could lead to coating of the tubes and may affect their chemical and physical characteristics. The aim of this study was to characterize the possible coatings of different functionalized MWCNTs in a cell free environment. Results To simulate the first contact in the lung, the tubes were coated with pulmonary surfactant and subsequently bound lipids were characterized. The further coating in the blood circulation was simulated by incubating the tubes in blood plasma. MWCNTs were amino (NH2- and carboxyl (-COOH-modified, in order to investigate the influence on the bound lipid and protein patterns. It was shown that surfactant lipids bind unspecifically to different functionalized MWCNTs, in contrast to the blood plasma proteins which showed characteristic binding patterns. Patterns of bound surfactant lipids were altered after a subsequent incubation in blood plasma. In addition, it was found that bound plasma protein patterns were altered when MWCNTs were previously coated with pulmonary surfactant. Conclusions A pulmonary surfactant coating and the functionalization of MWCNTs have both the potential to alter the MWCNTs blood plasma protein coating and to determine their properties and behaviour in biological systems.

  19. Exogenous Pulmonary Surfactant as a Vehicle for Antimicrobials: Assessment of Surfactant-Antibacterial Interactions In Vitro

    Directory of Open Access Journals (Sweden)

    Alexei Birkun

    2014-01-01

    Full Text Available Owing to its unique surface-active properties, an exogenous pulmonary surfactant may become a promising drug delivery agent, in particular, acting as a vehicle for antibiotics in topical treatment of pneumonia. The purpose of this study was to assess a mutual influence of natural surfactant preparation and three antibiotics (amikacin, cefepime, and colistimethate sodium in vitro and to identify appropriate combination(s for subsequent in vivo investigations of experimental surfactant/antibiotic mixtures. Influence of antibiotics on surface-active properties of exogenous surfactant was assessed using the modified Pattle method. Effects of exogenous surfactant on antibacterial activity of antimicrobials against Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were evaluated using conventional microbiologic procedures. Addition of amikacin or cefepime to surfactant had no significant influence on surface-active properties of the latter. Obvious reduction of surface-active properties was confirmed for surfactant/colistimethate composition. When suspended with antibiotics, surfactant either had no impact on their antimicrobial activity (amikacin or exerted mild to moderate influence (reduction of cefepime bactericidal activity and increase of colistimethate bacteriostatic activity against S. aureus and P. aeruginosa. Considering favorable compatibility profile, the surfactant/amikacin combination is advisable for subsequent investigation of joint surfactant/antibacterial therapy in animals with bacterial pneumonia.

  20. Exogenous Pulmonary Surfactant as a Vehicle for Antimicrobials: Assessment of Surfactant-Antibacterial Interactions In Vitro

    Science.gov (United States)

    2014-01-01

    Owing to its unique surface-active properties, an exogenous pulmonary surfactant may become a promising drug delivery agent, in particular, acting as a vehicle for antibiotics in topical treatment of pneumonia. The purpose of this study was to assess a mutual influence of natural surfactant preparation and three antibiotics (amikacin, cefepime, and colistimethate sodium) in vitro and to identify appropriate combination(s) for subsequent in vivo investigations of experimental surfactant/antibiotic mixtures. Influence of antibiotics on surface-active properties of exogenous surfactant was assessed using the modified Pattle method. Effects of exogenous surfactant on antibacterial activity of antimicrobials against Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were evaluated using conventional microbiologic procedures. Addition of amikacin or cefepime to surfactant had no significant influence on surface-active properties of the latter. Obvious reduction of surface-active properties was confirmed for surfactant/colistimethate composition. When suspended with antibiotics, surfactant either had no impact on their antimicrobial activity (amikacin) or exerted mild to moderate influence (reduction of cefepime bactericidal activity and increase of colistimethate bacteriostatic activity against S. aureus and P. aeruginosa). Considering favorable compatibility profile, the surfactant/amikacin combination is advisable for subsequent investigation of joint surfactant/antibacterial therapy in animals with bacterial pneumonia. PMID:24876994

  1. Small angle neutron scattering study of doxorubicin–surfactant ...

    Indian Academy of Sciences (India)

    The binding affinity of doxorubicin within the micelle carrier is enhanced through complex formation of drug and anionic surfactant, aerosol OT (AOT). Electrostatic binding of doxorubicin with negatively charged surfactants leads to the formation of hydrophobic drug–surfactant complexes. Surfactant-induced partitioning of ...

  2. Characterizing adsorption of associating surfactants on carbonates surfaces.

    Science.gov (United States)

    Jian, Guoqing; Puerto, Maura; Wehowsky, Anna; Miller, Clarence; Hirasaki, George J; Biswal, Sibani L

    2018-03-01

    The adsorption of anionic surfactants onto positively charged carbonate minerals is typically high due to electrostatic interactions. By blending anionic surfactants with cationic or zwitterionic surfactants, which naturally form surfactant complexes, surfactant adsorption is expected to be influenced by a competition between surfactant complexes and surfactant-surface interactions. The adsorption behavior of surfactant blends known to form complexes was investigated. The surfactants probed include an anionic C 15-18 internal olefin sulfonate (IOS), a zwitterionic lauryl betaine (LB), and an anionic C 13 -alcohol polyethylene glycol ether carboxylic acid (L38). An analytical method based on high-performance liquid chromatography evaporative light scattering detector (HPLC-ELSD) was developed to measure three individual surfactant concentrations from a blended surfactant solution. The adsorption of the individual surfactants and surfactant blends were systematically investigated on different mineral surfaces using varying brine solutions. LB adsorption on calcite surfaces was found to be significantly increased when blended with IOS or L38 since it forms surfactant complexes that partition to the surface. However, the total adsorption of the LB-IOS-L38 solution on dolomite decreased from 3.09 mg/m 2 to 1.97 mg/m 2 when blended together compared to summing the adsorption values of individual surfactants, which highlights the importance of mixed surfactant association. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. DNA compaction by azobenzene-containing surfactant

    International Nuclear Information System (INIS)

    Zakrevskyy, Yuriy; Kopyshev, Alexey; Lomadze, Nino; Santer, Svetlana; Morozova, Elena; Lysyakova, Ludmila; Kasyanenko, Nina

    2011-01-01

    We report on the interaction of cationic azobenzene-containing surfactant with DNA investigated by absorption and fluorescence spectroscopy, dynamic light scattering, and atomic force microscopy. The properties of the surfactant can be controlled with light by reversible switching of the azobenzene unit, incorporated into the surfactant tail, between a hydrophobic trans (visible irradiation) and a hydrophilic cis (UV irradiation) configuration. The influence of the trans-cis isomerization of the azobenzene on the compaction process of DNA molecules and the role of both isomers in the formation and colloidal stability of DNA-surfactant complexes is discussed. It is shown that the trans isomer plays a major role in the DNA compaction process. The influence of the cis isomer on the DNA coil configuration is rather small. The construction of a phase diagram of the DNA concentration versus surfactant/DNA charge ratio allows distancing between three major phases: colloidally stable and unstable compacted globules, and extended coil conformation. There is a critical concentration of DNA above which the compacted globules can be hindered from aggregation and precipitation by adding an appropriate amount of the surfactant in the trans configuration. This is because of the compensation of hydrophobicity of the globules with an increasing amount of the surfactant. Below the critical DNA concentration, the compacted globules are colloidally stable and can be reversibly transferred with light to an extended coil state.

  4. Surfactants tailored by the class Actinobacteria

    Directory of Open Access Journals (Sweden)

    Johannes H Kügler

    2015-03-01

    Full Text Available Gloablly, the drive towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application.

  5. Surfactants tailored by the class Actinobacteria

    Science.gov (United States)

    Kügler, Johannes H.; Le Roes-Hill, Marilize; Syldatk, Christoph; Hausmann, Rudolf

    2015-01-01

    Globally the change towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application. PMID:25852670

  6. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Rhamnolipids--next generation surfactants?

    Science.gov (United States)

    Müller, Markus Michael; Kügler, Johannes H; Henkel, Marius; Gerlitzki, Melanie; Hörmann, Barbara; Pöhnlein, Martin; Syldatk, Christoph; Hausmann, Rudolf

    2012-12-31

    The demand for bio-based processes and materials in the petrochemical industry has significantly increased during the last decade because of the expected running out of petroleum. This trend can be ascribed to three main causes: (1) the increased use of renewable resources for chemical synthesis of already established product classes, (2) the replacement of chemical synthesis of already established product classes by new biotechnological processes based on renewable resources, and (3) the biotechnological production of new molecules with new features or better performances than already established comparable chemically synthesized products. All three approaches are currently being pursued for surfactant production. Biosurfactants are a very promising and interesting substance class because they are based on renewable resources, sustainable, and biologically degradable. Alkyl polyglycosides are chemically synthesized biosurfactants established on the surfactant market. The first microbiological biosurfactants on the market were sophorolipids. Of all currently known biosurfactants, rhamnolipids have the highest potential for becoming the next generation of biosurfactants introduced on the market. Although the metabolic pathways and genetic regulation of biosynthesis are known qualitatively, the quantitative understanding relevant for bioreactor cultivation is still missing. Additionally, high product titers have been exclusively described with vegetable oil as sole carbon source in combination with Pseudomonas aeruginosa strains. Competitive productivity is still out of reach for heterologous hosts or non-pathogenic natural producer strains. Thus, on the one hand there is a need to gain a deeper understanding of the regulation of rhamnolipid production on process and cellular level during bioreactor cultivations. On the other hand, there is a need for metabolizable renewable substrates, which do not compete with food and feed. A sustainable bioeconomy approach should

  8. Gemini surfactants from natural amino acids.

    Science.gov (United States)

    Pérez, Lourdes; Pinazo, Aurora; Pons, Ramon; Infante, Mrosa

    2014-03-01

    In this review, we report the most important contributions in the structure, synthesis, physicochemical (surface adsorption, aggregation and phase behaviour) and biological properties (toxicity, antimicrobial activity and biodegradation) of Gemini natural amino acid-based surfactants, and some potential applications, with an emphasis on the use of these surfactants as non-viral delivery system agents. Gemini surfactants derived from basic (Arg, Lys), neutral (Ser, Ala, Sar), acid (Asp) and sulphur containing amino acids (Cys) as polar head groups, and Geminis with amino acids/peptides in the spacer chain are reviewed. © 2013.

  9. Mechanism of bacterial inactivation by cationic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pavlova, I.B.; Samoylenko, I.I.

    1985-03-01

    The mechanism of bacteriocidal action of the cationic surfactant dimethylbenzylammonium chloride was studied on exposure of Staphylococcus aureus, Streptococcus faecium, Bacillus subtilis and Escherichia coli to different concentrations of the agent and determinations of survival plots. The data showed that the surfactant was bacteriocidal for all the bacteria tested at a concentration of 0.0001%, but more efficient in the case of the gram positives. Electron microscopy showed considerable damage and dissarrangement of the cytoplasmic membrane, indicating that the killing mechanism involved this organelle. It appears that cationic surfactants may constitute effective disinfectant preparations. 9 references, 2 figures.

  10. Sugar ester surfactants: enzymatic synthesis and applications in food industry.

    Science.gov (United States)

    Neta, Nair S; Teixeira, José A; Rodrigues, Lígia R

    2015-01-01

    Sugar esters are non-ionic surfactants that can be synthesized in a single enzymatic reaction step using lipases. The stability and efficiency of lipases under unusual conditions and using non-conventional media can be significantly improved through immobilization and protein engineering. Also, the development of de novo enzymes has seen a significant increase lately under the scope of the new field of synthetic biology. Depending on the esterification degree and the nature of fatty acid and/or sugar, a range of sugar esters can be synthesized. Due to their surface activity and emulsifying capacity, sugar esters are promising for applications in food industry.

  11. Surfactant-Assisted Coal Liquefaction

    Science.gov (United States)

    Hickey, Gregory S.; Sharma, Pramod K.

    1993-01-01

    Obtaining liquid fuels from coal which are economically competitive with those obtained from petroleum based sources is a significant challenge for the researcher as well as the chemical industry. Presently, the economics of coal liquefaction are not favorable because of relatively intense processing conditions (temperatures of 430 degrees C and pressures of 2200 psig), use of a costly catalyst, and a low quality product slate of relatively high boiling fractions. The economics could be made more favorable by achieving adequate coal conversions at less intense processing conditions and improving the product slate. A study has been carried out to examine the effect of a surfactant in reducing particle agglomeration and improving hydrodynamics in the coal liquefaction reactor to increase coal conversions...

  12. Isolation of Surfactant-Resistant Bacteria from Natural, Surfactant-Rich Marine Habitats▿

    OpenAIRE

    Plante, Craig J.; Coe, Kieran M.; Plante, Rebecca G.

    2008-01-01

    Environmental remediation efforts often utilize either biodegradative microbes or surfactants, but not in combination. Coupling both strategies holds the potential to dramatically increase the rate and extent of remediation because surfactants can enhance the bioavailability of contaminants to microbes. However, many surfactants permeabilize bacterial cell membranes and are effective disinfectants. An important goal then is to find or genetically modify microorganisms that possess both desira...

  13. Pulmonary Surfactants for Acute and Chronic Lung Diseases (Part I

    Directory of Open Access Journals (Sweden)

    O. A. Rozenberg

    2014-01-01

    Full Text Available Part 1 of the review gives information on the composition and properties of a pulmonary surfactant and quantitative and qual itative impairments in the pulmonary surfactant system in different neonatal and adult abnormalities and describes the composition of commercial synthetic and natural surfactants. The results of surfactant therapy for respiratory distress syndrome and other lung diseases with secondary surfactant deficiency in the newborns are analyzed.

  14. Serum-surfactant SP-D correlates inversely to lung function in cystic fibrosis

    DEFF Research Database (Denmark)

    Olesen, Hanne Vebert; Holmskov, Uffe; Schiøtz, Peter Oluf

    2010-01-01

    BACKGROUND: Cystic fibrosis (CF) affects the lungs causing infections and inflammation. Surfactant protein D (SP-D) is an innate defense lectin primarily secreted in the lungs. We investigated the influence of the SP-D Met11Thr polymorphism on CF lung function; and serum SP-D as a marker for CF...

  15. Inhibition of pulmonary surfactant adsorption by serum and the mechanisms of reversal by hydrophilic polymers: theory

    DEFF Research Database (Denmark)

    Zasadzinski, Joseph A; Alig, T F; Alonso, Coralie

    2005-01-01

    A theory based on the Smolukowski analysis of colloid stability shows that the presence of charged, surface-active serum proteins at the alveolar air-liquid interface can severely reduce or eliminate the adsorption of lung surfactant from the subphase to the interface, consistent with the observa...

  16. Effects of surfactant/budesonide therapy on oxidative modifications in the lung in experimental meconium-induced lung injury.

    Science.gov (United States)

    Mikolka, P; Kopincova, J; Tomcikova Mikusiakova, L; Kosutova, P; Antosova, M; Calkovska, A; Mokra, D

    2016-02-01

    Meconium aspiration syndrome (MAS) is a serious condition, which can be treated with exogenous surfactant and mechanical ventilation. However, meconium-induced inflammation, lung edema and oxidative damage may inactivate delivered surfactant and thereby reduce effectiveness of the therapy. As we presumed that addition of anti-inflammatory agent into the surfactant may alleviate inflammation and enhance efficiency of the therapy, this study was performed to evaluate effects of surfactant therapy enriched with budesonide versus surfactant-only therapy on markers of oxidative stress in experimental model of MAS. Meconium suspension (25 mg/ml, 4 ml/kg) was instilled into the trachea of young rabbits, whereas one group of animals received saline instead of meconium (C group, n = 6). In meconium-instilled animals, respiratory failure developed within 30 min. Then, meconium-instilled animals were divided into 3 groups according to therapy (n = 6 each): with surfactant therapy (M + S group), with surfactant + budesonide therapy (M + S + B), and without therapy (M group). Surfactant therapy consisted of two bronchoalveolar lavages (BAL) with diluted surfactant (Curosurf, 5 mg phospholipids/ml, 10 ml/kg) followed by undiluted surfactant (100 mg phospholipids/kg), which was in M + S + B group enriched with budesonide (Pulmicort, 0.5 mg/ml). Animals were oxygen-ventilated for additional 5 hours. At the end of experiment, blood sample was taken for differential white blood cell (WBC) count. After euthanizing animals, left lung was saline-lavaged and cell differential in BAL was determined. Oxidative damage, i.e. oxidation of lipids (thiobarbituric acid reactive substance (TBARS) and conjugated dienes) and proteins (dityrosine and lysine-lipoperoxidation products) was estimated in lung homogenate and isolated mitochondria. Total antioxidant capacity was evaluated in lung homogenate and plasma. Meconium instillation increased transmigration of neutrophils and production of free

  17. Surfactant Apoprotein D in Preterm Neonates with Acute Respiratory Distress Syndrome

    Directory of Open Access Journals (Sweden)

    S. A. Perepelitsa

    2009-01-01

    Full Text Available Objective: to study the production of surfactant apoprotein D in preterm neonates with acute respiratory distress syndrome (ARDS during artificial ventilation (AV. Subjects and methods. The paper presents the results of studying the production of surfactant protein D (SP-D in various biological fluids in 44 preterm neonates. Two groups of newborn infants were identified according to the clinical manifestations of ARDS. The study group comprised 25 infants with the severe course of the disease, in this connection the preventive administration of the exogenous surfactant Curosurf and AV were made in all the neonates at birth. The control group included 19 preterm babies without signs of ARDS. Results. The study has demonstrated that in parturients and preterm neonatal infants, surfactant apoprotein D is detectable in various biological fluids: amniotic fluid, the gastric aspirate obtained just after birth, residual umbilical cord blood, serum following 8 hours of birth, and bronchoalveolar fluid. Despite the low gestational age of the neonates, the lung surfactant system is able to produce SP-D, as evidenced by its high content in the amniotic fluid and residual umbilical cord blood of preterm neonates. The production of apoprotein D in preterm neonates considerably reduces in the next few hours after birth. Conclusion. The findings suggest that fetal tissues generate SP-D, which improves pulmonary gas exchange in preterm neonates in the first hours after birth and that alveolar-capillary membrane dysfunctions are transient in the neonates on AV. Key words: preterm neonates, acute respiratory distress syndrome, surfactant, surfactant apoprotein D.

  18. Poly(ethylene oxide) surfactant polymers

    OpenAIRE

    VACHEETHASANEE, KATANCHALEE; WANG, SHUWU; QIU, YONGXING; MARCHANT, ROGER E.

    2004-01-01

    We report on a series of structurally well-defined surfactant polymers that undergo surface-induced self-assembly on hydrophobic biomaterial surfaces. The surfactant polymers consist of a poly(vinyl amine) backbone with poly(ethylene oxide) and hexanal pendant groups. The poly(vinyl amine) (PVAm) was synthesized by hydrolysis of poly(N-vinyl formamide) following free radical polymerization of N-vinyl formamide. Hexanal and aldehyde-terminated poly (ethyleneoxide) (PEO) were simultaneously att...

  19. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2003-07-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate wettability. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies.

  20. Thermodynamics of non-ionic surfactant Triton X-100-cationic surfactants mixtures at the cloud point

    International Nuclear Information System (INIS)

    Batigoec, Cigdem; Akbas, Halide; Boz, Mesut

    2011-01-01

    Highlights: → Non-ionic surfactants are used as emulsifier and solubilizate in such as textile, detergent and cosmetic. → Non-ionic surfactants occur phase separation at temperature as named the cloud point in solution. → Dimeric surfactants have attracted increasing attention due to their superior surface activity. → The positive values of ΔG cp 0 indicate that the process proceeds nonspontaneous. - Abstract: This study investigates the effects of gemini and conventional cationic surfactants on the cloud point (CP) of the non-ionic surfactant Triton X-100 (TX-100) in aqueous solutions. Instead of visual observation, a spectrophotometer was used for measurement of the cloud point temperatures. The thermodynamic parameters of these mixtures were calculated at different cationic surfactant concentrations. The gemini surfactants of the alkanediyl-α-ω-bis (alkyldimethylammonium) dibromide type, on the one hand, with different alkyl groups containing m carbon atoms and an ethanediyl spacer, referred to as 'm-2-m' (m = 10, 12, and 16) and, on the other hand, with -C 16 alkyl groups and different spacers containing s carbon atoms, referred to as '16-s-16' (s = 6 and 10) were synthesized, purified and characterized. Additions of the cationic surfactants to the TX-100 solution increased the cloud point temperature of the TX-100 solution. It was accepted that the solubility of non-ionic surfactant containing polyoxyethylene (POE) hydrophilic chain was a maximum at the cloud point so that the thermodynamic parameters were calculated at this temperature. The results showed that the standard Gibbs free energy (ΔG cp 0 ), the enthalpy (ΔH cp 0 ) and the entropy (ΔS cp 0 ) of the clouding phenomenon were found positive in all cases. The standard free energy (ΔG cp 0 ) increased with increasing hydrophobic alkyl chain for both gemini and conventional cationic surfactants; however, it decreased with increasing surfactant concentration.

  1. Preparation, Characterization and Performance Studies of Active PVDF Ultrafiltration-Surfactants Membranes Containing PVP as Additive

    International Nuclear Information System (INIS)

    Nur Izzah Md Fadilah; Abdul Rahman Hassan

    2016-01-01

    The role of surfactants in the formation of active Poly(vinylidene fluoride) (PVDF) ultrafiltration (AUF) membranes was studied. The effect combination of surfactants that are Sodium dodecyl sulfate (SDS)/ Tween 80 and Tween 80/ Triton X-100 formulations on performance and morphological structures were investigated for the first time. The influence of surfactants blends on the membrane pores was also examined. Experimental data showed that combination of Tween 80/ Triton X-100 give the highest BSA permeation flux with a value of 285.51 Lm -2 h -1 . With combination of SDS/ Tween 80, the AUF membrane showed the highest protein rejection up to 93 % and 79 % for Bovine Serum Albumin (BSA) and Egg Albumin (EA), respectively. Moreover, membranes characterization demonstrated that the addition of SDS/ Tween 80 and Tween 80/ Triton X-100 were found to affect the performance, surface morphologies and membrane pores of AUF PVDF membranes. (author)

  2. Cellular uptake and processing of surfactant lipids and apoprotein SP-A by rat lung

    International Nuclear Information System (INIS)

    Young, S.L.; Wright, J.R.; Clements, J.A.

    1989-01-01

    The intracellular pathways and the kinetics of metabolism of surfactant apoprotein and lipid, which may be recycled from the alveolar space, are largely unknown. We used a lipid-apoprotein complex made from liposomes of pure lipids in a ratio found in mammalian pulmonary surfactant plus surfactant apoprotein (SP-A, Mr = 26,000-36,000) to test some possible relationships in the recycling of these major surfactant components between intrapulmonary compartments. After intratracheal instillation of 80 microliters of an apoprotein-liposome mixture with separate radiolabels in the lipid and the apoprotein, rats were killed at times from 8 min to 4 h later. The lungs were lavaged with saline, and subcellular fractions were isolated on discontinuous sucrose density gradients. Both the [ 14 C]lipid radiolabel and the 125 I-apoprotein radiolabel demonstrated a time-dependent increase in radioactivity recovered in a lamellar body-enriched fraction. Uptake of the radiolabels into other subcellular fractions did not exhibit a clear-cut time dependence; more of the protein than the lipid radiolabel was found in the Golgi-rich and microsomal fractions. We conclude that both the lipid and apoprotein portions of lung surfactant are taken up by lung cells and are incorporated into secretory granules of the cells

  3. Interactions of organic contaminants with mineral-adsorbed surfactants

    Science.gov (United States)

    Zhu, L.; Chen, B.; Tao, S.; Chiou, C.T.

    2003-01-01

    Sorption of organic contaminants (phenol, p-nitrophenol, and naphthalene) to natural solids (soils and bentonite) with and without myristylpyridinium bromide (MPB) cationic surfactant was studied to provide novel insight to interactions of contaminants with the mineral-adsorbed surfactant. Contaminant sorption coefficients with mineral-adsorbed surfactants, Kss, show a strong dependence on surfactant loading in the solid. At low surfactant levels, the Kss values increased with increasing sorbed surfactant mass, reached a maximum, and then decreased with increasing surfactant loading. The Kss values for contaminants were always higher than respective partition coefficients with surfactant micelles (Kmc) and natural organic matter (Koc). At examined MPB concentrations in water the three organic contaminants showed little solubility enhancement by MPB. At low sorbed-surfactant levels, the resulting mineral-adsorbed surfactant via the cation-exchange process appears to form a thin organic film, which effectively "adsorbs" the contaminants, resulting in very high Kss values. At high surfactant levels, the sorbed surfactant on minerals appears to form a bulklike medium that behaves essentially as a partition phase (rather than an adsorptive surface), with the resulting Kss being significantly decreased and less dependent on the MPB loading. The results provide a reference to the use of surfactants for remediation of contaminated soils/sediments or groundwater in engineered surfactant-enhanced washing.

  4. Surfactant nebulization versus instillation during high frequency ventilation in surfactant-deficient rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1998-01-01

    Surfactant nebulization improves lung function at low alveolar doses of surfactant. However, efficiency of nebulization is low, and lung deposition seems to depend on lung aeration. High frequency ventilation (HFV) has been shown to improve lung aeration. We hypothesize that the combination of HFV

  5. Size control of surfactant vesicles made by a mixture of cationic surfactants and organic derivatives.

    Science.gov (United States)

    Kim, Tae-Hwan; Han, Young-Soo; Jang, Jong-Dae; Seong, Baek-Seok

    2014-10-01

    Spontaneous size-controllable vesicles that are prepared by a mixture of surfactants with different alkyl chain lengths (n-alkyltrimethylammonium bromide, C(n)TAB) and an organic derivative (5-methyl salicylic acid, 5mS) in aqueous solution have been investigated. When the organic derivative 5mS is mixed with the C(n)TAB surfactants in aqueous solution, the surfactant vesicles are spontaneously formed above a certain 5mS concentration. Small angle neutron scattering reveals that the core radius of surfactant vesicles is clearly increased from ca. 31 nm to ca. 97 nm with the alkyl chain length of surfactants while the bilayer thickness of the vesicles is nearly constant. The structure of surfactant vesicles maintains against temperature change ranging from 30 degrees C to 45 degrees C, showing no structural change. These results can provide thermally stable surfactant vesicles with various sizes and constant bilayer thickness that may possess a different permeability and may allow the surfactant vesicle to be used in gene or drug delivery for a variety of goods.

  6. Rosin Surfactant QRMAE Can Be Utilized as an Amorphous Aggregate Inducer: A Case Study of Mammalian Serum Albumin.

    Directory of Open Access Journals (Sweden)

    Mohd Ishtikhar

    Full Text Available Quaternary amine of diethylaminoethyl rosin ester (QRMAE, chemically synthesized biocompatible rosin based cationic surfactant, has various biological applications including its use as a food product additive. In this study, we examined the amorphous aggregation behavior of mammalian serum albumins at pH 7.5, i.e., two units above their isoelectric points (pI ~5.5, and the roles played by positive charge and hydrophobicity of exogenously added rosin surfactant QRMAE. The study was carried out on five mammalian serum albumins, using various spectroscopic methods, dye binding assay, circular dichroism and electron microscopy. The thermodynamics of the binding of mammalian serum albumins to cationic rosin modified surfactant were established using isothermal titration calorimetry (ITC. It was observed that a suitable molar ratio of protein to QRMAE surfactant enthusiastically induces amorphous aggregate formation at a pH above two units of pI. Rosin surfactant QRMAE-albumins interactions revealed a unique interplay between the initial electrostatic and the subsequent hydrophobic interactions that play an important role towards the formation of hydrophobic interactions-driven amorphous aggregate. Amorphous aggregation of proteins is associated with varying diseases, from the formation of protein wine haze to the expansion of the eye lenses in cataract, during the expression and purification of recombinant proteins. This study can be used for the design of novel biomolecules or drugs with the ability to neutralize factor(s responsible for the aggregate formation, in addition to various other industrial applications.

  7. Surfactant Delivery into the Lung

    Science.gov (United States)

    Grotberg, James; Filoche, Marcel

    2014-11-01

    We have developed a multiscale, compartmentalized model of surfactant and liquid delivery into the lung. Assuming liquid plug propagation, the airway compartment accounts for the plug's volume deposition (coating) on the airway wall, while the bifurcation compartment accounts for plug splitting from the parent airway to the two daughter airways. Generally the split is unequal due to gravity and geometry effects. Both the deposition ratio RD (deposition volume/airway volume), and the splitting ratio, RS, of the daughters volumes are solved independently from one another. Then they are used in a 3D airway network geometry to achieve the distribution of delivery into the lung. The airway geometry is selected for neonatal as well as adult applications, and can be advanced from symmetric, to stochastically asymmetric, to personalized. RD depends primarily on the capillary number, Ca, while RS depends on Ca, the Reynolds number, Re, the Bond number, Bo, the dose volume, VD, and the branch angles. The model predicts the distribution of coating on the airway walls and the remaining plug volume delivered to the alveolar region at the end of the tree. Using this model, we are able to simulate and test various delivery protocols, in order to optimize delivery and improve the respiratory function.

  8. High-efficiency type II cell-enhanced green fluorescent protein expression facilitates cellular identification, tracking, and isolation.

    Science.gov (United States)

    Vanderbilt, Jeff N; Gonzalez, Robert F; Allen, Lennell; Gillespie, AnneMarie; Leaffer, David; Dean, Willow B; Chapin, Cheryl; Dobbs, Leland G

    2015-07-01

    We have developed a transgenic mouse expressing enhanced green fluorescent protein (EGFP) in virtually all type II (TII) alveolar epithelial cells. The CBG mouse (SPC-BAC-EGFP) contains a bacterial artificial chromosome modified to express EGFP within the mouse surfactant protein (SP)-C gene 3' untranslated region. EGFP mRNA expression is limited to the lung. EGFP fluorescence is both limited to and exhibited by all cells expressing pro-SP-C; fluorescence is uniform throughout all lobes of the lung and does not change as mice age. EGFP(+) cells also express SP-B but do not express podoplanin, a type I (TI) cell marker. CBG mice show no evidence of lung disease with aging. In 3 hours, TII cells can be isolated in >99% purity from CBG mice by FACS; the yield of 3.7 ± 0.6 × 10(6) cells represents approximately 25 to 60% of the TII cells in the lung. By FACS analysis, approximately 0.9% of TII cells are in mitosis in uninjured lungs; after bleomycin injury, 4.1% are in mitosis. Because EGFP fluorescence can be detected for >14 days in culture, at a time that SP-C mRNA expression is essentially nil, this line may be useful for tracking TII cells in culture and in vivo. When CBG mice are crossed to transgenic mice expressing rat podoplanin, TI and TII cells can be easily simultaneously identified and isolated. When bred to other strains of mice, EGFP expression can be used to identify TII cells without the need for immunostaining for SP-C. These mice should be useful in models of mouse pulmonary disease and in studies of TII cell biology, biochemistry, and genetics.

  9. Dilute Surfactant Methods for Carbonate Formations

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2006-02-01

    There are many fractured carbonate reservoirs in US (and the world) with light oil. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). The process of using dilute anionic surfactants in alkaline solutions has been investigated in this work for oil recovery from fractured oil-wet carbonate reservoirs both experimentally and numerically. This process is a surfactant-aided gravity drainage where surfactant diffuses into the matrix, lowers IFT and contact angle, which decrease capillary pressure and increase oil relative permeability enabling gravity to drain the oil up. Anionic surfactants have been identified which at dilute concentration of 0.05 wt% and optimal salinity can lower the interfacial tension and change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil. The force of adhesion in AFM of oil-wet regions changes after anionic surfactant treatment to values similar to those of water-wet regions. The AFM topography images showed that the oil-wetting material was removed from the surface by the anionic surfactant treatment. Adsorption studies indicate that the extent of adsorption for anionic surfactants on calcite minerals decreases with increase in pH and with decrease in salinity. Surfactant adsorption can be minimized in the presence of Na{sub 2}CO{sub 3}. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (20-42% OOIP in 50 days; up to 60% in 200 days) for initially oil-wet cores through wettability alteration and IFT reduction. Small (<10%) initial gas saturation does not affect significantly the rate of oil recovery in the imbibition process, but larger gas saturation decreases the oil recovery rate. As the core permeability decreases, the rate of oil recovery reduces

  10. Role of linker groups between hydrophilic and hydrophobic moieties of cationic surfactants on oligonucleotide-surfactant interactions.

    Science.gov (United States)

    Santhiya, Deenan; Dias, Rita S; Shome, Anshupriya; Das, Prasanta Kumar; Miguel, Maria G; Lindman, Björn; Maiti, Souvik

    2009-12-15

    The interaction between DNA and amino-acid-based surfactants with different linker groups was investigated by gel electrophoresis, ethidium bromide exclusion assays, circular dichroism, and melting temperature determinations. The studies showed that the strength of the interaction between the oligonucleotides and the surfactants is highly dependent on the linker of the surfactant. For ester surfactants, no significant interaction was observed for surfactant-to-DNA charge ratios up to 12. On the other hand, amide surfactants were shown to interact strongly with the oligonucleotides; these surfactants could displace up to 75% of the ethidium bromide molecules bound to the DNA and induced significant changes in the circular dichroism spectra. When comparing the headgroups of the surfactants, it was observed that surfactants with more hydrophobic headgroups (proline vs alanine) interacted more strongly with the DNA, in good agreement with previous studies.

  11. The effects of alkylammonium counterions on the aggregation of fluorinated surfactants and surfactant ionic liquids.

    Science.gov (United States)

    Pottage, Matthew J; Greaves, Tamar L; Garvey, Christopher J; Tabor, Rico F

    2016-08-01

    The effects of organic counterions with varying carbon number on surfactant aggregation have been analysed by coupling perfluorooctanoate surfactant anions with various alkylammonium counterions. Both the degree of substitution (primary to tertiary) and alkyl chain length (0-3 carbons) of the counterions were varied to provide a comprehensive matrix of geometries and lipophilicities. Surface activity was measured using pendant drop tensiometry, while temperature-controlled small-angle neutron scattering was used to probe changes in aggregation morphology. It was found that the use of such alkylammonium counterions resulted in a strong preference for bilayer formation even at low surfactant concentration (surfactant-rich lamellar phase coexists with a dilute micellar phase. The results indicate that aggregation is controlled by a delicate balance of counterion size, hydrophilicity and diffuseness of charge, providing new methods for the subtle control of surfactant solutions. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  12. Isolation of surfactant-resistant bacteria from natural, surfactant-rich marine habitats.

    Science.gov (United States)

    Plante, Craig J; Coe, Kieran M; Plante, Rebecca G

    2008-08-01

    Environmental remediation efforts often utilize either biodegradative microbes or surfactants, but not in combination. Coupling both strategies holds the potential to dramatically increase the rate and extent of remediation because surfactants can enhance the bioavailability of contaminants to microbes. However, many surfactants permeabilize bacterial cell membranes and are effective disinfectants. An important goal then is to find or genetically modify microorganisms that possess both desirable degradative capabilities and the ability to thrive in the presence of surfactants. The guts of some marine invertebrates, particularly deposit feeders, have previously been shown to contain high levels of biosurfactants. Our primary aim was to mine these natural, surfactant-rich habitats for surfactant-resistant bacteria. Relative to sediment porewaters, the gut contents of two polychaete deposit feeders, Nereis succinea and Amphitrite ornata, exhibited a significantly higher ratio of bacteria resistant to both cationic and anionic surfactants. In contrast, bacteria in the gut fluids of a holothuroid, Leptosynapta tenuis, showed surfactant susceptibility similar to that of bacteria from sediments. Analyses of 16S rRNA gene sequences revealed that the majority of surfactant-resistant isolates were previously undescribed species of the genus Vibrio or were of a group most closely related to Spongiobacter spp. We also tested a subset of resistant bacteria for the production of biosurfactants. The majority did produce biosurfactants, as demonstrated via the oil-spreading method, but in all cases, production was relatively weak under the culture conditions employed. Novel surfactant-resistant, biosurfactant-producing bacteria, and the habitats from which they were isolated, provide a new source pool for potential microorganisms to be exploited in the in situ bioremediation of marine sediments.

  13. Isolation of Surfactant-Resistant Bacteria from Natural, Surfactant-Rich Marine Habitats▿

    Science.gov (United States)

    Plante, Craig J.; Coe, Kieran M.; Plante, Rebecca G.

    2008-01-01

    Environmental remediation efforts often utilize either biodegradative microbes or surfactants, but not in combination. Coupling both strategies holds the potential to dramatically increase the rate and extent of remediation because surfactants can enhance the bioavailability of contaminants to microbes. However, many surfactants permeabilize bacterial cell membranes and are effective disinfectants. An important goal then is to find or genetically modify microorganisms that possess both desirable degradative capabilities and the ability to thrive in the presence of surfactants. The guts of some marine invertebrates, particularly deposit feeders, have previously been shown to contain high levels of biosurfactants. Our primary aim was to mine these natural, surfactant-rich habitats for surfactant-resistant bacteria. Relative to sediment porewaters, the gut contents of two polychaete deposit feeders, Nereis succinea and Amphitrite ornata, exhibited a significantly higher ratio of bacteria resistant to both cationic and anionic surfactants. In contrast, bacteria in the gut fluids of a holothuroid, Leptosynapta tenuis, showed surfactant susceptibility similar to that of bacteria from sediments. Analyses of 16S rRNA gene sequences revealed that the majority of surfactant-resistant isolates were previously undescribed species of the genus Vibrio or were of a group most closely related to Spongiobacter spp. We also tested a subset of resistant bacteria for the production of biosurfactants. The majority did produce biosurfactants, as demonstrated via the oil-spreading method, but in all cases, production was relatively weak under the culture conditions employed. Novel surfactant-resistant, biosurfactant-producing bacteria, and the habitats from which they were isolated, provide a new source pool for potential microorganisms to be exploited in the in situ bioremediation of marine sediments. PMID:18586977

  14. Small angle neutron scattering studies on protein denaturation ...

    Indian Academy of Sciences (India)

    The conformation of the unfolded protein in the presence of surfactant has been determined directly using contrast variation SANS measurements by contrast matching surfactant molecules. The protein acquires a random coil Gaussian conformation on unfolding with its radius of gyration increasing with increase in ...

  15. Recovering hydrocarbons with surfactants from lignin

    Energy Technology Data Exchange (ETDEWEB)

    Naae, D.G.; Whittington, L.E.; Ledoux, W.A.; Debons, F.E.

    1988-11-29

    This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation through an injection well a surfactant slug comprising about 0.1% to about 10% by weight of surfactants produced from lignin, the surfactants produced by placing lignin in contact with water, converting the lignin into low molecular weight lignin phenols by reducing the lignin in the presence of a reducing agent of carbon monoxide or hydrogen creating a reduction reaction mixture comprising oil soluble lignin phenols, the reduction occurring at a temperature greater than about 200/sup 0/C and a pressure greater than about 100 psi, recovering the oil soluble lignin phenols from the reduction mixture, and converting the lignin phenols into lignin surfactants by a reaction selected from the group consisting of alkoxylation, sulfonation, sulfation, aklylation, sulfomethylation, and alkoxysulfation; injecting into the formation through the injection well a drive fluid to push the surfactant slug towards a production well; and recovering hydrocarbons at the production well.

  16. History of surfactant up to 1980.

    Science.gov (United States)

    Obladen, Michael

    2005-01-01

    Remarkable insight into disturbed lung mechanics of preterm infants was gained in the 18th and 19th century by the founders of obstetrics and neonatology who not only observed respiratory failure but also designed devices to treat it. Surfactant research followed a splendid and largely logical growth curve. Pathological changes in the immature lung were characterized in Germany by Virchow in 1854 and by Hochheim in 1903. The Swiss physiologist von Neergard fully understood surfactant function in 1929, but his paper was ignored for 25 years. The physical properties of surfactant were recognized in the early 1950s from research on warfare chemicals by Pattle in Britain and by Radford and Clements in the United States. The causal relationship of respiratory distress syndrome (RDS) and surfactant deficiency was established in the USA by Avery and Mead in 1959. The Australian obstetrician Liggins induced lung maturity with glucocorticoids in 1972, but his discovery was not fully believed for another 20 years. A century of basic research was rewarded when Fujiwara introduced surfactant substitution in Japan in 1980 for treatment and prevention of RDS. Copyright 2005 S. Karger AG, Basel

  17. Surface shear inviscidity of soluble surfactants.

    Science.gov (United States)

    Zell, Zachary A; Nowbahar, Arash; Mansard, Vincent; Leal, L Gary; Deshmukh, Suraj S; Mecca, Jodi M; Tucker, Christopher J; Squires, Todd M

    2014-03-11

    Foam and emulsion stability has long been believed to correlate with the surface shear viscosity of the surfactant used to stabilize them. Many subtleties arise in interpreting surface shear viscosity measurements, however, and correlations do not necessarily indicate causation. Using a sensitive technique designed to excite purely surface shear deformations, we make the most sensitive and precise measurements to date of the surface shear viscosity of a variety of soluble surfactants, focusing on SDS in particular. Our measurements reveal the surface shear viscosity of SDS to be below the sensitivity limit of our technique, giving an upper bound of order 0.01 μN·s/m. This conflicts directly with almost all previous studies, which reported values up to 10(3)-10(4) times higher. Multiple control and complementary measurements confirm this result, including direct visualization of monolayer deformation, for SDS and a wide variety of soluble polymeric, ionic, and nonionic surfactants of high- and low-foaming character. No soluble, small-molecule surfactant was found to have a measurable surface shear viscosity, which seriously undermines most support for any correlation between foam stability and surface shear rheology of soluble surfactants.

  18. Surfactant use with nitrate-based bioremediation

    International Nuclear Information System (INIS)

    Wilson, B.H.; Hutchins, S.R.; West, C.C.

    1995-01-01

    This study presents results of an initial survey on the effect of six surfactants on the biodegradation of petroleum hydrocarbons in bioremediation applications using nitrate as the electron acceptor. Aquifer material from Park City, Kansas, was used for the study. The three atomic surfactants chosen were Steol CS-330, Dowfax 8390 and sodium dodecylbenzene sulfonate (SDBS); the three nonionic surfactants were T-MAZ-60, Triton X-100, and Igepal CO-660. Both Steol CS-330 and T-MAZ-60 biodegraded under denitrifying conditions. The Steol inhibited biodegradation of benzene, toluene, ethylbenzene, xylenes, and trimethylbenzenes (BTEXTMB). Only toluene was rapidly degraded in the presence of T-MAZ-60. Biodegradation of all compounds, including toluene, appears to be inhibited by Dowfax 8390 and SDBS. No biodegradation of Dowfax 8390 or SDBS was observed. SDBS inhibited denitrification, but Dowfax 8390 did not. For the microcosms containing Triton X-100 or Igepal CO-660, removal of toluene, ethylbenzene, m-xylene, 1,3,5-TMB, and 1,2,4-TMB were similar to their removals in the no-surfactant treatment. These two surfactants did not biodegrade, did not inhibit biodegradation of the alkylbenzenes, and did not inhibit denitrification. Further studies are continuing with aquifer material from Eglin Air Force Base

  19. Foaming behaviour of polymer-surfactant solutions

    International Nuclear Information System (INIS)

    Cervantes-MartInez, Alfredo; Maldonado, Amir

    2007-01-01

    We study the effect of a non-ionic amphiphilic polymer (PEG-100 stearate also called Myrj 59) on the foaming behaviour of aqueous solutions of an anionic surfactant (sodium dodecyl sulfate or SDS). The SDS concentration was kept fixed while the Myrj 59 concentration was varied. Measurements of foamability, surface tension and electrical conductivity were carried out. The results show two opposite effects depending on the polymer concentration: foamability is higher when the Myrj 59 concentration is low; however, it decreases considerably when the polymer concentration is increased. This behaviour is due to the polymer adsorption at the air/liquid interface at lower polymer concentrations, and to the formation of a polymer-surfactant complex in the bulk at higher concentrations. The results are confirmed by surface tension and electrical conductivity measurements, which are interpreted in terms of the microstructure of the polymer-surfactant solutions. The observed behaviour is due to the amphiphilic nature of the studied polymer. The increased hydrophobicity of Myrj 59, compared to that of water-soluble polymers like PEG or PEO, increases its 'reactivity' towards SDS, i.e. the strength of its interaction with this anionic surfactant. Our results show that hydrophobically modified polymers have potential applications as additives in order to control the foaming properties of surfactant solutions

  20. Syntheses of surfactants from oleochemical epoxides

    Directory of Open Access Journals (Sweden)

    Warwel Siegfried

    2001-01-01

    Full Text Available Sugar-based surfactants were obtained in good yields (up to 100% under mild conditions (70°C, methanol or mixtures of methanol and water by ring-opening of terminal epoxides with aminopolyols, derived from glucose. Reaction of N-methyl glucamine with epoxides from even-numbered C4-C18 alpha-olefins or from terminal unsaturated fatty acid methyl esters leads to linear products, while corresponding reactions with N-dodecyl glucamine or glucamine yield surfactants with different Y-structures. Products obtained by conversion of omega-epoxy fatty acid methyl esters were saponificated with NaOH or hydrolyzed enzymatically to sodium salts or free acids respectively, which are amphoteric surfactants. Studies of the surfactants at different pH-values demonstrate different surface active properties in aqueous solutions. Critical micelle concentrations (c.m.c. in a range between 2 and 500mg/l and surface tensions of 25-40mN/m were measured for several of the synthesized sugar-based surfactants. The ring-opening products are rather poor foamers, whereas some of the corresponding hydrobromides show good foaming properties.

  1. Surface active complexes formed between keratin polypeptides and ionic surfactants.

    Science.gov (United States)

    Pan, Fang; Lu, Zhiming; Tucker, Ian; Hosking, Sarah; Petkov, Jordan; Lu, Jian R

    2016-12-15

    Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C 12 TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes. Copyright © 2016. Published by Elsevier Inc.

  2. Elevated plasma surfactant protein D (SP-D) levels and a direct correlation with anti-severe acute respiratory syndrome coronavirus-specific IgG antibody in SARS patients

    DEFF Research Database (Denmark)

    Wu, Y P; Liu, Z H; Wei, R

    2009-01-01

    Pulmonary SP-D is a defence lectin promoting clearance of viral infections. SP-D is recognized to bind the S protein of SARS-CoV and enhance phagocytosis. Moreover, systemic SP-D is widely used as a biomarker of alveolar integrity. We investigated the relation between plasma SP-D, SARS-type pneum...

  3. Pulmonary haptoglobin (pHp) is part of the surfactant system in the human lung.

    Science.gov (United States)

    Abdullah, Mahdi; Goldmann, Torsten

    2012-11-20

    Since the existence of pHp was demonstrated, it has been shown that this molecule and its receptor CD163 are regulated by different stimuli. Furthermore, a comparably fast secretion of pHp was described as well as the immuno-stimulatory effects. The intention of this study was to elucidate the role of pHp in the human lungs further. Here we show, by means of confocal microscopy and immune-electron-microscopy, a clear co-localization of pHp with surfactant protein-B in lamellar bodies of alveolar epithelial cells type II. These results are underlined by immunohistochemical stainings in differently fixed human lung tissues, which show pHp in vesicular and released form. The images of the released form resemble the intended position of surfactant in the human alveolus. pHp is secreted by Alveolar epithelial cells type II as previously shown. Moreover, pHp is co-localized with Surfactant protein-B. We conclude that the presented data shows that pHp is a native part of the surfactant system in the human lung. http://www.diagnosticpathology.diagnomx.eu/vs/2563584738239912.

  4. Synthesis of mesoporous nano-hydroxyapatite by using zwitterions surfactant

    Science.gov (United States)

    Mesoporous nano-hydroxyapatite (mn-HAP) was successfully synthesized via a novel micelle-templating method using lauryl dimethylaminoacetic acid as zwitterionic surfactant. The systematic use of such a surfactant in combination with microwave energy inputenables the precise contr...

  5. Fullerene surfactants and their use in polymer solar cells

    Science.gov (United States)

    Jen, Kwan-Yue; Yip, Hin-Lap; Li, Chang-Zhi

    2015-12-15

    Fullerene surfactant compounds useful as interfacial layer in polymer solar cells to enhance solar cell efficiency. Polymer solar cell including a fullerene surfactant-containing interfacial layer intermediate cathode and active layer.

  6. Lung inflammatory and oxidative alterations after exogenous surfactant therapy fortified with budesonide in rabbit model of meconium aspiration syndrome.

    Science.gov (United States)

    Mikolka, P; Kopincová, J; Košútová, P; Čierny, D; Čalkovská, A; Mokrá, D

    2016-12-22

    Meconium aspiration syndrome (MAS) triggers inflammatory and oxidative pathways which can inactivate both pulmonary surfactant and therapeutically given exogenous surfactant. Glucocorticoid budesonide added to exogenous surfactant can inhibit inflammation and thereby enhance treatment efficacy. Neonatal meconium (25 mg/ml, 4 ml/kg) was administered intratracheally (i.t.) to rabbits. When the MAS model was prepared, animals were treated with budesonide i.t. (Pulmicort, 0.25 mg/kg, M+B); with surfactant lung lavage (Curosurf®, 10 ml/kg, 5 mg phospholipids/ml, M+S) followed by undiluted Curosurf® i.t. (100 mg phospholipids/kg); with combination of budesonide and surfactant (M+S+B); or were untreated (M); or served as controls with saline i.t. instead of meconium (C). Animals were oxygen-ventilated for additional 5 h. Cell counts in the blood and bronchoalveolar lavage fluid (BAL), lung edema formation (wet/dry weight ratio), oxidative damage of lipids/ proteins and inflammatory expression profiles (IL-2, IL-6, IL-13, TNF-alpha) in the lung homogenate and plasma were determined. Combined surfactant+budesonide therapy was the most effective in reduction of neutrophil counts in BAL, oxidative damage, levels and mRNA expression of cytokines in the lung, and lung edema formation compared to untreated animals. Curosurf fortified with budesonide mitigated lung inflammation and oxidative modifications what indicate the perspectives of this treatment combination for MAS therapy.

  7. Recent food applications of microbial surfactants.

    Science.gov (United States)

    Nitschke, Marcia; Silva, Sumária Sousa E

    2016-07-20

    Owing to their natural origin and environmental compatibility, interest in microbial surfactants or biosurfactants has gained attention during last few years. These characteristics fulfill the demand of regulatory agencies and society to use more sustained and green chemicals. Microbial-derived surfactants can replace synthetic surfactants in a great variety of industrial applications as detergents, foaming, emulsifiers, solubilizers, and wetting agents. Change in the trend of consumers toward natural from synthetic additives and the increasing health and environmental concerns have created demand for new "green" additives in foods. Apart from their inherent surface-active properties, biosurfactants have shown antimicrobial and anti-biofilm activities against food pathogens; therefore, biosurfactants can be versatile additives or ingredients of food processing. These interesting applications will be discussed in this review.

  8. Surfactant mediated liquid phase exfoliation of graphene

    Science.gov (United States)

    Narayan, Rekha; Kim, Sang Ouk

    2015-10-01

    Commercialization of graphene based applications inevitably requires cost effective mass production. From the early days of research on graphene, direct liquid phase exfoliation (LPE) of graphite has been considered as the most promising strategy to produce high-quality mono or few-layer graphene sheets in solvent dispersion forms. Substantial success has been achieved thus far in the LPE of graphene employing numerous solvent systems and suitable surfactants. This invited review article principally showcase the recent research progress as well as shortcomings of surfactant assisted LPE of graphene. In particular, a comprehensive assessment of the quality and yield of the graphene sheets produced by different categories of the surfactants are summarized. Future direction of LPE methods is also proposed for the eventual success of commercial applications.

  9. Nanotube Dispersions Made With Charged Surfactant

    Science.gov (United States)

    Kuper, Cynthia; Kuzma, Mike

    2006-01-01

    Dispersions (including monodispersions) of nanotubes in water at relatively high concentrations have been formulated as prototypes of reagents for use in making fibers, films, and membranes based on single-walled carbon nanotubes (SWNTs). Other than water, the ingredients of a dispersion of this type include one or more charged surfactant(s) and carbon nanotubes derived from the HiPco(TradeMark) (or equivalent) process. Among reagents known to be made from HiPco(TradeMark)(or equivalent) SWNTs, these are the most concentrated and are expected to be usable in processing of bulk structures and materials. Test data indicate that small bundles of SWNTs and single SWNTs at concentrations up to 1.1 weight percent have been present in water plus surfactant. This development is expected to contribute to the growth of an industry based on applied carbon nanotechnology. There are expected to be commercial applications in aerospace, avionics, sporting goods, automotive products, biotechnology, and medicine.

  10. Surfactant studies for bench-scale operation

    Science.gov (United States)

    Hickey, Gregory S.; Sharma, Pramod K.

    1993-01-01

    A phase 2 study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the second quarter of work. The major accomplishments were: completion of coal liquefaction autoclave reactor runs with Illinois number 6 coal at processing temperatures of 300, 325, and 350 C, and pressures of 1800 psig; analysis of the filter cake and the filtrate obtained from the treated slurry in each run; and correlation of the coal conversions and the liquid yield quality to the surfactant concentration. An increase in coal conversions and upgrading of the liquid product quality due to surfactant addition was observed for all runs.

  11. Brine-resistant sulfonate surfactants for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Stournas, S.

    1983-01-01

    One of the most severe limitations of surfactant waterflooding is the instability of the commonly employed surfactants in the usual ionic environments of oil reservoirs. A specific modification to the usual structure of sulfonate surfactants not only makes them immune to high concentrations of monovalent and divalent cations, but also enables them to act as stabilizer of the common surfactants and to displace tertiary oil in brines of high salinity and divalent ion content.

  12. A Review on Progress in QSPR Studies for Surfactants

    OpenAIRE

    Zhengwu Wang; Xiaoyi Zhang; Jiwei Hu

    2010-01-01

    This paper presents a review on recent progress in quantitative structure-property relationship (QSPR) studies of surfactants and applications of various molecular descriptors. QSPR studies on critical micelle concentration (cmc) and surface tension (γ) of surfactants are introduced. Studies on charge distribution in ionic surfactants by quantum chemical calculations and its effects on the structures and properties of the colloids of surfactants are also reviewed. The trends of QSPR studies o...

  13. Xylem Surfactants Introduce a New Element to the Cohesion-Tension Theory1[OPEN

    Science.gov (United States)

    Espino, Susana; Nima, Neda; Do, Aissa Y.T.; Michaud, Joseph M.; Papahadjopoulos-Sternberg, Brigitte; Yang, Jinlong; Steppe, Kathy

    2017-01-01

    Vascular plants transport water under negative pressure without constantly creating gas bubbles that would disable their hydraulic systems. Attempts to replicate this feat in artificial systems almost invariably result in bubble formation, except under highly controlled conditions with pure water and only hydrophilic surfaces present. In theory, conditions in the xylem should favor bubble nucleation even more: there are millions of conduits with at least some hydrophobic surfaces, and xylem sap is saturated or sometimes supersaturated with atmospheric gas and may contain surface-active molecules that can lower surface tension. So how do plants transport water under negative pressure? Here, we show that angiosperm xylem contains abundant hydrophobic surfaces as well as insoluble lipid surfactants, including phospholipids, and proteins, a composition similar to pulmonary surfactants. Lipid surfactants were found in xylem sap and as nanoparticles under transmission electron microscopy in pores of intervessel pit membranes and deposited on vessel wall surfaces. Nanoparticles observed in xylem sap via nanoparticle-tracking analysis included surfactant-coated nanobubbles when examined by freeze-fracture electron microscopy. Based on their fracture behavior, this technique is able to distinguish between dense-core particles, liquid-filled, bilayer-coated vesicles/liposomes, and gas-filled bubbles. Xylem surfactants showed strong surface activity that reduces surface tension to low values when concentrated as they are in pit membrane pores. We hypothesize that xylem surfactants support water transport under negative pressure as explained by the cohesion-tension theory by coating hydrophobic surfaces and nanobubbles, thereby keeping the latter below the critical size at which bubbles would expand to form embolisms. PMID:27927981

  14. Xylem Surfactants Introduce a New Element to the Cohesion-Tension Theory.

    Science.gov (United States)

    Schenk, H Jochen; Espino, Susana; Romo, David M; Nima, Neda; Do, Aissa Y T; Michaud, Joseph M; Papahadjopoulos-Sternberg, Brigitte; Yang, Jinlong; Zuo, Yi Y; Steppe, Kathy; Jansen, Steven

    2017-02-01

    Vascular plants transport water under negative pressure without constantly creating gas bubbles that would disable their hydraulic systems. Attempts to replicate this feat in artificial systems almost invariably result in bubble formation, except under highly controlled conditions with pure water and only hydrophilic surfaces present. In theory, conditions in the xylem should favor bubble nucleation even more: there are millions of conduits with at least some hydrophobic surfaces, and xylem sap is saturated or sometimes supersaturated with atmospheric gas and may contain surface-active molecules that can lower surface tension. So how do plants transport water under negative pressure? Here, we show that angiosperm xylem contains abundant hydrophobic surfaces as well as insoluble lipid surfactants, including phospholipids, and proteins, a composition similar to pulmonary surfactants. Lipid surfactants were found in xylem sap and as nanoparticles under transmission electron microscopy in pores of intervessel pit membranes and deposited on vessel wall surfaces. Nanoparticles observed in xylem sap via nanoparticle-tracking analysis included surfactant-coated nanobubbles when examined by freeze-fracture electron microscopy. Based on their fracture behavior, this technique is able to distinguish between dense-core particles, liquid-filled, bilayer-coated vesicles/liposomes, and gas-filled bubbles. Xylem surfactants showed strong surface activity that reduces surface tension to low values when concentrated as they are in pit membrane pores. We hypothesize that xylem surfactants support water transport under negative pressure as explained by the cohesion-tension theory by coating hydrophobic surfaces and nanobubbles, thereby keeping the latter below the critical size at which bubbles would expand to form embolisms. © 2017 American Society of Plant Biologists. All Rights Reserved.

  15. Surfactant induced complex formation and their effects on the interfacial properties of seawater.

    Science.gov (United States)

    Guzmán, Eduardo; Santini, Eva; Benedetti, Alessandro; Ravera, Francesca; Ferrari, Michele; Liggieri, Libero

    2014-11-01

    The effect of a cationic surfactant, hexadecyltrimethylammonium bromide (CTAB), on the interfacial properties of seawater has been studied by dynamic and equilibrium surface tension and by dilational rheology essays. Important modifications of the surface tension and dilational rheology response have been observed already at the very low CTAB concentrations, where the effects due to the high ionic strength are negligible. The comparison with the effects of CTAB in different seawater models, or in natural seawater fractions, points out the establishment of strong interactions between the surfactant molecules and the lipophilic fraction of organic material dispersed/dissolved in seawater, affecting the interfacial activity of the molecules. Considering the biochemical richness of seawater, these results can be explained assuming interaction mechanisms and adsorption schemes similar to those speculated for protein and other macromolecules in the presence of surfactants, which in fact show similar features. Thus already at the low concentrations the surfactant molecules form highly surface-active complexes with part of the organic fraction of seawater. At the larger surfactant concentrations these complexes compete for adsorption with an excess of free CTAB molecules which, according to the thermodynamic conditions, are most favoured to occupy the liquid interface. The results of this study underline the important role of the sea organic content in enhancing the surface-activity of surfactants, which is relevant for a deeper understand of the direct and indirect effects of these types of pollutants on the physico-chemical environment in the sea coastal areas and develop mitigation strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Effect of SP-C on surface potential distribution in pulmonary surfactant: Atomic force microscopy and Kelvin probe force microscopy study

    International Nuclear Information System (INIS)

    Hane, Francis; Moores, Brad; Amrein, Matthias; Leonenko, Zoya

    2009-01-01

    The air-lung interface is covered by a molecular film of pulmonary surfactant (PS). The major function of the film is to reduce the surface tension of the lung's air-liquid interface, providing stability to the alveolar structure and reducing the work of breathing. Earlier we have shown that function of bovine lipid extract surfactant (BLES) is related to the specific molecular architecture of surfactant films. Defined molecular arrangement of the lipids and proteins of the surfactant film also give rise to a local highly variable electrical surface potential of the interface. In this work we investigated a simple model of artificial lung surfactant consisting of DPPC, eggPG, and surfactant protein C (SP-C). Effects of surface compression and the presence of SP-C on the monolayer structure and surface potential distribution were investigated using atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM). We show that topography and locally variable surface potential of DPPC-eggPG lipid mixture are similar to those of pulmonary surfactant BLES in the presence of SP-C and differ in surface potential when SP-C is absent.

  17. Novel surfactant-selective membrane electrode based on polyelectrolyte-surfactant complex.

    Science.gov (United States)

    Zorin, Ivan; Scherbinina, Tatiana; Fetin, Petr; Makarov, Ivan; Bilibin, Alexander

    2014-12-01

    Novel class of active ionophores for surfactant selective electrodes is proposed. PVC membrane doped with polyelectrolyte-surfactant stoichiometric complex is used for ion-selective electrode construction responsive to cetyltrimethyl ammonium bromide and related surfactants. New ionophore is quite stable and completely insoluble in aqueous media in wide range of pH. The electrode displays nearly Nernstian slope in CTAB concentration range 10(-6)-10(-3)M. Polyelectrolyte platform allows to design wide range of different ionophores responsive to cationic organic substances. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. INTERACTIONS BETWEEN WATER-SOLUBLE NONIONIC POLYMERS AND SURFACTANT AGGREGATES

    NARCIS (Netherlands)

    BRACKMAN, JC; ENGBERTS, JBFN; Herb, CA; Prudhomme, RK

    1994-01-01

    The influence of the chemical structure and charge of the surfactant on polymer-micelle interaction has been studied using various ionic and non-ionic surfactants, and surfactants of which the charge can be varied by (de)protonation. Octylthioglucoside, dodecyldimethylamine-oxide, alkylphosphates,

  19. Phenanthrene partitioning in sediment-surfactant-fresh/saline water systems

    International Nuclear Information System (INIS)

    Sun Hongwen; Wu Wenling; Wang Lei

    2009-01-01

    The objective of this study was to investigate the influence of salinity on the effectiveness of surfactants in the remediation of sediments contaminated with phenanthrene (PHE). This is an example of a more general application of surfactants in removing hydrophobic organic compounds (HOCs) from contaminated soil/sediment in saline environments via in-situ enhanced sorption or ex-situ soil washing. Salinity effects on surfactant micelle formation and PHE partitioning into solution surfactant micelles and sorbed surfactant were investigated. The critical micelle concentration of surfactants decreased, and PHE partition between surfactant micelles and water increased with increasing salinity. Carbon-normalized partition coefficients (K ss ) of PHE onto the sorbed cationic surfactant increased significantly with increasing salinity, which illustrates a more pronounced immobilization of PHE by cationic surfactant in a saline system. Reduction of PHE sorption by anionic surfactant was more pronounced in the saline system, indicating that the anionic surfactant has a higher soil washing effectiveness in saline systems. - The effectiveness of surfactant-enhanced remediation technology was promoted when applying it in estuarine environment with a higher salinity.

  20. The Inhibiting or Accelerating Effect of Different Surfactants on ...

    African Journals Online (AJOL)

    NICO

    The course of differential capacity curves of the electric double layer at the mercury electrode/surfactant solution interface was described for three different surfactants from different groups. Using square-wave voltammetry (SWV) it was found that the surfactants had a varying effect on the kinetics of electroreduction of Zn2+ ...

  1. Micellization of a Cationic Surfactant in Mixed Aqueous and Non ...

    African Journals Online (AJOL)

    Reception

    surfactant molecules arrange themselves in bulk solutions into aggregates otherwise called micelles when the interface is fully saturated with the surfactant molecules. Micelle formation is driven by hydrophobic effect but opposed by electrostatic repulsion of the ionic head group (Jiang et al., 2009). Cationic surfactants like ...

  2. Adsorption of anionic surfactants in limestone medium during oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Canbolat, Serhat; Bagci, Suat [Middle East Technical Univ., Dept. of Petroleum and Natural Gas Engineering, Ankara (Turkey)

    2004-07-15

    Foam-forming surfactant performance was evaluated by several experimental methods (interfacial tension, foam stability, corefloods) using commercial surfactants. There is considerable interest in the use of foam-forming surfactants for mobility control in water flood. To provide effective mobility control, the injected surfactant must propagate from the injection well toward the production well. One of the important parameters affecting propagation of foam-forming surfactant through the reservoir is the retention of surfactant due to its adsorption on reservoir rock. The determination of the adsorption of foam-forming surfactants in limestone reservoirs is important for the residual oil recovery efficiency. Adsorption measurements, recovery efficiencies, and surfactant and alkaline flooding experiments carried out with the representative of the selected surfactants alkaline solutions, linear alkyl benzene sulphonic acid (LABSA), sodium lauryl ether sulfate (SLES), and NaOH in a limestone medium. These surfactants were selected with respect to their foaming ability. Calibration curves formed by pH measurements were used to determine the correct adsorption amount of the used surfactants and recovery efficiency of these surfactants compared with base waterflooding. The results showed that LABSA adsorbed more than SLES in limestone reservoirs. The recovery efficiency of SLES was higher than the recovery efficiency of LABSA, and they decreased the recovery efficiency with respect to only the water injection case. (Author)

  3. Effects of selected surfactants on soil microbial activity

    Science.gov (United States)

    Surfactants (surface-active agents) facilitate and accentuate the emulsifying, dispersing, spreading, and wetting properties of liquids. Surfactants are used in industry to reduce the surface tension of liquid and to solubilize compounds. For agricultural pest management, surfactants are an import...

  4. Transport of biological molecules in surfactant-alginate composite hydrogels.

    Science.gov (United States)

    Stoppel, Whitney L; White, Joseph C; Horava, Sarena D; Bhatia, Surita R; Roberts, Susan C

    2011-11-01

    Obstructed transport of biological molecules can result in improper release of pharmaceuticals or biologics from biomedical devices. Recent studies have shown that nonionic surfactants, such as Pluronic® F68 (F68), positively alter biomaterial properties such as mesh size and microcapsule diameter. To further understand the effect of F68 (incorporated at concentrations well above the critical micelle concentration (CMC)) in traditional biomaterials, the transport properties of BSA and riboflavin were investigated in F68-alginate composite hydrogels, formed by both internal and external cross-linking with divalent cations. Results indicate that small molecule transport (represented by riboflavin) was not significantly hindered by F68 in homogeneously (internally) cross-linked hydrogels (up to an 11% decrease in loading capacity and 14% increase in effective diffusion coefficient, D(eff)), while protein transport in homogeneously cross-linked hydrogels (represented by BSA) was significantly affected (up to a 43% decrease in loading capacity and 40% increase in D(eff)). For inhomogeneously cross-linked hydrogels (externally cross-linked by CaCl(2) or BaCl(2)), the D(eff) increased up to 50 and 83% for small molecules and proteins, respectively. Variation in the alginate gelation method was shown to affect transport through measurable changes in swelling ratio (30% decrease) and observable changes in cross-linking structure as well as up to a 3.6- and 11.8-fold difference in D(eff) for riboflavin and BSA, respectively. Aside from the expected significant changes due to the cross-linking method utilized, protein transport properties were altered due to mesh size restrictions (10-25 nm estimated by mechanical properties) and BSA-F68 interaction (DLS). Taken as a whole, these results show that incorporation of a nonionic surfactant at concentrations above the CMC can affect device functionality by impeding the transport of large biological molecules. Copyright © 2011

  5. Re-dissolution and de-compaction of DNA-cationic surfactant complexes using non-ionic surfactants.

    Science.gov (United States)

    Corbyn, Conrad P; Fletcher, Paul D I; Gemici, Rabia; Dias, Rita S; Miguel, Maria G

    2009-12-28

    Addition of a cationic surfactant to a solution of DNA causes the formation of compacted DNA-cationic surfactant complexes which precipitate from aqueous solution. It has been shown previously that addition of anionic surfactant will re-dissolve and de-compact the DNA-cationic surfactant complexes and we find that addition of non-ionic surfactants of the alkylpolyoxyethylene type can be used similarly. In principle, these de-compaction and re-dissolution processes could occur either by stripping of the cationic surfactant from the DNA into mixed micelles with the non-ionic surfactant or by solubilisation of the DNA-cationic surfactant complexes within the non-ionic micelles. Solubility phase-boundary measurements, fluorescence microscopy observations of the de-compaction process and light scattering results indicate that de-compaction and re-dissolution occur by the stripping mechanism, even for non-ionic surfactants where the favourable attractive electrostatic interaction between the two surfactants is absent. Using measurements of critical micelle concentrations and calculations based on regular solution mixed micelle theory, we show that re-dissolution and de-compaction of the DNA-cationic surfactant complexes occurs when the concentration of free monomeric cationic surfactant is reduced (by incorporation into mixed micelles) below a critical value.

  6. Ki-67 acts as a biological surfactant to disperse mitotic chromosomes

    Science.gov (United States)

    Cuylen, Sara; Blaukopf, Claudia; Politi, Antonio Z.; Müller-Reichert, Thomas; Neumann, Beate; Poser, Ina; Ellenberg, Jan; Hyman, Anthony A.; Gerlich, Daniel W.

    2016-01-01

    Summary Eukaryotic genomes are partitioned into chromosomes, which during mitosis form compact and spatially well-separated mechanical bodies1–3.This enables chromosomes to move independently of each other for segregation of precisely one copy of the genome to each of the nascent daughter cells. Despite insights into the spatial organization of mitotic chromosomes4 and the discovery of proteins at the chromosome surface3,5,6, the molecular and biophysical basis of mitotic chromosome individuality have remained unclear. We report that Ki-67, a component of the mitotic chromosome periphery, prevents chromosomes from collapsing into a single chromatin mass after nuclear envelope disassembly, thus enabling independent chromosome motility and efficient interactions with the mitotic spindle. The chromosome separation function of Ki-67 is not confined within a specific protein domain but correlates with size and net charge of truncation mutants that apparently lack secondary structure. This suggests that Ki-67 forms a steric and electrical barrier, similar to surface-active agents (surfactants) that disperse particles or phase-separated liquid droplets in solvents. Fluorescence correlation spectroscopy showed a high surface density of Ki-67 and dual-color labeling of both protein termini revealed an extended molecular conformation, indicating brush-like arrangements that are characteristic for polymeric surfactants. Our study thus elucidates a biomechanical role of the mitotic chromosome periphery and suggests that natural proteins can function as surfactants in intracellular compartmentalization. PMID:27362226

  7. Thermodynamics of non-ionic surfactant Triton X-100-cationic surfactants mixtures at the cloud point

    Energy Technology Data Exchange (ETDEWEB)

    Batigoec, Cigdem [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey); Akbas, Halide, E-mail: hakbas34@yahoo.com [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey); Boz, Mesut [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey)

    2011-12-15

    Highlights: > Non-ionic surfactants are used as emulsifier and solubilizate in such as textile, detergent and cosmetic. > Non-ionic surfactants occur phase separation at temperature as named the cloud point in solution. > Dimeric surfactants have attracted increasing attention due to their superior surface activity. > The positive values of {Delta}G{sub cp}{sup 0} indicate that the process proceeds nonspontaneous. - Abstract: This study investigates the effects of gemini and conventional cationic surfactants on the cloud point (CP) of the non-ionic surfactant Triton X-100 (TX-100) in aqueous solutions. Instead of visual observation, a spectrophotometer was used for measurement of the cloud point temperatures. The thermodynamic parameters of these mixtures were calculated at different cationic surfactant concentrations. The gemini surfactants of the alkanediyl-{alpha}-{omega}-bis (alkyldimethylammonium) dibromide type, on the one hand, with different alkyl groups containing m carbon atoms and an ethanediyl spacer, referred to as 'm-2-m' (m = 10, 12, and 16) and, on the other hand, with -C{sub 16} alkyl groups and different spacers containing s carbon atoms, referred to as '16-s-16' (s = 6 and 10) were synthesized, purified and characterized. Additions of the cationic surfactants to the TX-100 solution increased the cloud point temperature of the TX-100 solution. It was accepted that the solubility of non-ionic surfactant containing polyoxyethylene (POE) hydrophilic chain was a maximum at the cloud point so that the thermodynamic parameters were calculated at this temperature. The results showed that the standard Gibbs free energy ({Delta}G{sub cp}{sup 0}), the enthalpy ({Delta}H{sub cp}{sup 0}) and the entropy ({Delta}S{sub cp}{sup 0}) of the clouding phenomenon were found positive in all cases. The standard free energy ({Delta}G{sub cp}{sup 0}) increased with increasing hydrophobic alkyl chain for both gemini and conventional cationic

  8. Physicochemical characteristics of PFC surfactants for dry decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Won Jin; Lee, Chi Woo [Korea University, Seoul (Korea)

    2001-04-01

    Even the trace amount of the used nuclear fuels of high radioactivity are hazardous to the earth and humans. Perfluorocarbons and perfluorocarbon surfactants are emerging to be efficient chemicals in the dry decontamination process of the used fuels of high radioactivity. The theme was undertaken to increase the knowledge on perfluorocarbon surfactants to develop the perfluorocarbon system in the dry decontamination process in Korea. Several cationic and anionic pfc surfactants were synthesized. Effects of pfc surfactants on electrochemical etching of silicon were investigated to form porous silicons. Forces were measured between silicon surfaces and AFM tip in the absence and presence of pfc surfactants. 7 refs., 10 figs. (Author)

  9. Thermally stable surfactants and compositions and methods of use thereof

    Science.gov (United States)

    Chaiko, David J [Woodridge, IL

    2008-09-02

    There are provided novel thermally stable surfactants for use with fillers in the preparation of polymer composites and nanocomposites. Typically, surfactants of the invention are urethanes, ureas or esters of thiocarbamic acid having a hydrocarbyl group of from 10 to 50 carbons and optionally including an ionizable or charged group (e.g., carboxyl group or quaternary amine). Thus, there are provided surfactants having Formula I: ##STR00001## wherein the variables are as defined herein. Further provided are methods of making thermally stable surfactants and compositions, including composites and nanocomposites, using fillers coated with the surfactants.

  10. Surfactant enhanced non-classical extraction

    International Nuclear Information System (INIS)

    Szymanowski, J.

    1999-01-01

    Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilization abilities are also discussed. (author)

  11. Lung Surfactant - The Indispensable Component of Respiratory ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 8. Lung Surfactant - The Indispensable Component of Respiratory Mechanics. Shweta Saxena. Research News Volume 10 Issue 8 August 2005 pp 91-96. Fulltext. Click here to view fulltext PDF. Permanent link:

  12. Topological transformation of a surfactant bilayer

    DEFF Research Database (Denmark)

    Le, T.D.; Olsson, U.; Mortensen, K.

    2000-01-01

    Surfactant lamellar phases are often complicated by the formation of multilamellar (onions) under shear, which can originate simply by shaking the sample. A systematic study has been performed on the C10E3-D2O system in which different bilayer structures under a steady shear flow were investigated...

  13. EFFECT OF SURFACTANTS ON THE MECHANICAL PROPERTIES ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the effect of non ionic surfactant on the mechanical properties of acetaminophen-wax matrix tablet and hence its implication on dissolution profile. Acetaminophen-wax matrix granules were prepared by melt granulation technique. This was formed by triturating acetaminophen ...

  14. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    Nanohydroxyapatite particles with different morphologies were synthesized through a microwave coupled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant. The concentration ...

  15. Surfactant free metal chalcogenides microparticles consisting of ...

    Indian Academy of Sciences (India)

    SANYASINAIDU GOTTAPU

    2017-11-11

    Nov 11, 2017 ... Abstract. A versatile methodology for the production of organic surfactant-free metal chalcogenide microparticles consisting of nano crystallites at room temperature in a short time is described. The reaction of various metal sources with LiBH4 in the presence of either S or Se yielded their corresponding ...

  16. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    Abstract. Nanohydroxyapatite particles with different morphologies were synthesized through a microwave cou- pled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant.

  17. Surfactants, interfaces and pores : a theoretical study

    NARCIS (Netherlands)

    Huinink, H.

    1998-01-01

    The aim of this study was to investigate the behavior of surfactants in porous media by theoretical means. The influence of curvature of a surface on the adsorption has been studied with a mean field lattice (MFL) model, as developed by Scheutjens and Fleer. An analytical theory has been

  18. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2003-01-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have acquired field oil and core samples and field brine compositions from Marathon. We have conducted preliminary adsorption and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Receding contact angles increase with surfactant adsorption. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies.

  19. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    4Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 012, India. MS received 17 ... fibres is achieved through this method by controlling the concentration of the surfactant. The concentration of the ... shown that many clinical applications of HAp mainly depend on shape ...

  20. Intratracheal atomized surfactant provides similar outcomes as bolus surfactant in preterm lambs with respiratory distress syndrome.

    Science.gov (United States)

    Milesi, Ilaria; Tingay, David G; Zannin, Emanuela; Bianco, Federico; Tagliabue, Paolo; Mosca, Fabio; Lavizzari, Anna; Ventura, Maria Luisa; Zonneveld, C Elroy; Perkins, Elizabeth J; Black, Don; Sourial, Magdy; Dellacá, Raffaele L

    2016-07-01

    Aerosolization of exogenous surfactant remains a challenge. This study is aimed to evaluate the efficacy of atomized poractant alfa (Curosurf) administered with a novel atomizer in preterm lambs with respiratory distress syndrome. Twenty anaesthetized lambs, 127 ± 1 d gestational age, (mean ± SD) were instrumented before birth and randomized to receive either (i) positive pressure ventilation without surfactant (Control group), (ii) 200 mg/kg of bolus instilled surfactant (Bolus group) at 10 min of life or (iii) 200 mg/kg of atomized surfactant (Atomizer group) over 60 min from 10 min of life. All lambs were ventilated for 180 min with a standardized protocol. Lung mechanics, regional lung compliance (electrical impedance tomography), and carotid blood flow (CBF) were measured with arterial blood gas analysis. Dynamic compliance and oxygenation responses were similar in the Bolus and Atomizer groups, and both better than Control by 180 min (all P < 0.05; two-way ANOVA). Both surfactant groups demonstrated more homogeneous regional lung compliance throughout the study period. There were no differences in CBFConclusion:In a preterm lamb model, atomized surfactant resulted in similar gas exchange and mechanics as bolus administration. This study suggests evaluation of supraglottic atomization with this system when noninvasive support is warranted.

  1. Lung surfactants and different contributions to thin film stability.

    Science.gov (United States)

    Hermans, Eline; Bhamla, M Saad; Kao, Peter; Fuller, Gerald G; Vermant, Jan

    2015-11-07

    The surfactant lining the walls of the alveoli in the lungs increases pulmonary compliance and prevents collapse of the lung at the end of expiration. In premature born infants, surfactant deficiency causes problems, and lung surfactant replacements are instilled to facilitate breathing. These pulmonary surfactants, which form complex structured fluid-fluid interfaces, need to spread with great efficiency and once in the alveolus they have to form a thin stable film. In the present work, we investigate the mechanisms affecting the stability of surfactant-laden thin films during spreading, using drainage flows from a hemispherical dome. Three commercial lung surfactant replacements Survanta, Curosurf and Infasurf, along with the phospholipid dipalmitoylphosphatidylcholine (DPPC), are used. The surface of the dome can be covered with human alveolar epithelial cells and experiments are conducted at the physiological temperature. Drainage is slowed down due to the presence of all the different lung surfactant replacements and therefore the thin films show enhanced stability. However, a scaling analysis combined with visualization experiments demonstrates that different mechanisms are involved. For Curosurf and Infasurf, Marangoni stresses are essential to impart stability and interfacial shear rheology does not play a role, in agreement with what is observed for simple surfactants. Survanta, which was historically the first natural surfactant used, is rheologically active. For DPPC the dilatational properties play a role. Understanding these different modes of stabilization for natural surfactants can benefit the design of effective synthetic surfactant replacements for treating infant and adult respiratory disorders.

  2. Influence of stability of polymer surfactant on oil displacement mechanism

    Science.gov (United States)

    Liu, Li; Li, Chengliang; Pi, Yanming; Wu, Di; He, Ying; Geng, Liang

    2018-02-01

    At present, most of the oilfields of China have entered the late stage of high water-cut development, and three oil recovery technique has become the leading technology for improving oil recovery. With the improvement of three oil recovery techniques, the polymer surfactant flooding technology has been widely promoted in oil fields in recent years. But in the actual field experiment, it has been found that the polymer surfactant has chromatographic separation at the extraction end, which indicates that the property of the polymer surfactant has changed during the displacement process. At present, there was few literature about how the stability of polymer surfactant affects the oil displacement mechanism. This paper used HuaDing-I polymer surfactant to conduct a micro photolithography glass flooding experiment, and then compared the oil displacement law of polymer surfactant before and after static setting. Finally, the influence law of stability of polymer surfactant on the oil displacement mechanism is obtained by comprehensive analysis.

  3. Status of surfactants as penetration enhancers in transdermal drug delivery

    Directory of Open Access Journals (Sweden)

    Iti Som

    2012-01-01

    Full Text Available Surfactants are found in many existing therapeutic, cosmetic, and agro-chemical preparations. In recent years, surfactants have been employed to enhance the permeation rates of several drugs via transdermal route. The application of transdermal route to a wider range of drugs is limited due to significant barrier to penetration across the skin which is associated with the outermost stratum corneum layer. Surfactants have effects on the permeability characteristics of several biological membranes including skin. They have the potential to solubilize lipids within the stratum corneum. The penetration of the surfactant molecule into the lipid lamellae of the stratum corneum is strongly dependent on the partitioning behavior and solubility of surfactant. Surfactants ranging from hydrophobic agents such as oleic acid to hydrophilic sodium lauryl sulfate have been tested as permeation enhancer to improve drug delivery. This article reviews the status of surfactants as permeation enhancer in transdermal drug delivery of various drugs.

  4. Lessons from the biophysics of interfaces: Lung surfactant and tear fluid

    DEFF Research Database (Denmark)

    Rantamaki, A.; Telenius, J.; Koivuniemi, A.

    2011-01-01

    to the epithelium and an anterior lipid layer at the air-water interface. The aqueous layers contain soluble proteins and metabolites, and they are responsible for the host defence system and nutrition of the organ. However, many proteins also interact with the lipid layer and are important for the surface...... proportion and the spectrum of different polar and non-polar lipids seem to be more extensive in tear fluid than in lung surfactant. The differing lipid compositions generate distinctive lipid layer structures. Despite the structural differences, these lipid layers decrease the surface tension of the air......-water interface. The structure of the tear film lipid layer also minimises the evaporation of the tear fluid. In lung surfactant surface activity is crucial for the function of the organ, as the lipid layer prevents the collapse of the lung alveoli during the compression-expansion cycle of breathing. Similarly...

  5. "The effects of polysorbate surfactants on the structure of mucus Glycoproteins "

    Directory of Open Access Journals (Sweden)

    Sajadi Tabassi A

    2001-07-01

    Full Text Available A dynamic oscillatory technique was used to assess the effect of polysorbate non-ionic surfactants on mucus rheology. Adherent mucus gel was scraped from the surface mucosa of pig stomachs and purified by gel exclusion chromatography followed by ultrafiltration and gelation. Rheological measurements of this gel were carried out on a Carri-Med Controlled Stress Rheometer. Appropriate volumes of surfactant solution were added to weighed samples of mucus gel so that a final concentration of 20 mM surfactant was achieved in a gel containing 8% w/w solids content. Polysorbate 20 (PS20, polysorbate 40 (PS40, polysorbate 60 (PS60 and polysorbate 80 (PS80 all decreased both storage (elastic modulus G’ and loss (viscous modulus G’’ significantly at 10 Hz (PPS20>PS60>PS40. The mechanisms by which surfactants disturb the mucus structure are not fully understood, nonetheless, they could possibly affect the mucus gel properties by causing depletion of the glycoprotein constituents such as non-mucin proteins and mucin associated lipids. This might lead to the conclusion that polysorbates, by reducing the viscoelasticity of mucus gel could alleviate its barrier properties and facilitate the diffusion of concomitantly administered drugs via mucus gel.

  6. Influence of Surfactants on Sodium Chloride Crystallization in Confinement.

    Science.gov (United States)

    Qazi, Mohsin J; Liefferink, Rinse W; Schlegel, Simon J; Backus, Ellen H G; Bonn, Daniel; Shahidzadeh, Noushine

    2017-05-02

    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.

  7. The impact of nonionic surfactant additives on the nonequilibrium association between oppositely charged polyelectrolytes and ionic surfactants.

    Science.gov (United States)

    Fegyver, Edit; Mészáros, Róbert

    2014-03-28

    The effect of uncharged surfactant additives on the oppositely charged polyion/ionic surfactant complexation is usually described as a direct equilibrium association between the polyelectrolyte molecules and free mixed micelles analogous to the polyion/colloidal particle interactions. This approach predicts that the binding of the ionic surfactant to the polyelectrolyte molecules can be completely suppressed by increasing the nonionic-to-ionic surfactant ratio. In the present work, it is shown that the addition of nonionic surfactants to poly(diallyldimethylammonium chloride)/sodium dodecyl sulfate mixtures considerably enhances the binding of the anionic surfactant to the polycation in the dilute surfactant concentration regime. The dynamic light scattering, turbidity, electrophoretic mobility and fluorescence spectroscopic measurements are consistent with the synergic binding of the ionic and nonionic surfactants to the polyelectrolyte molecules. The enhanced surfactant binding could be utilized for the preparation of stable colloidal dispersions of novel polyion/mixed surfactant nanoparticles over a wide composition range provided that adequate mixing protocols are used. These results clearly indicate that the nonionic surfactant additives can be successfully used to tune the nonequilibrium association of oppositely charged macromolecules and amphiphiles.

  8. Structure and Conformational Dynamics of DMPC/Dicationic Surfactant and DMPC/Dicationic Surfactant/DNA Systems

    Science.gov (United States)

    Pietralik, Zuzanna; Krzysztoń, Rafał; Kida, Wojciech; Andrzejewska, Weronika; Kozak, Maciej

    2013-01-01

    Amphiphilic dicationic surfactants, known as gemini surfactants, are currently studied for gene delivery purposes. The gemini surfactant molecule is composed of two hydrophilic “head” groups attached to hydrophobic chains and connected via molecular linker between them. The influence of different concentrations of 1,5-bis (1-imidazolilo-3- decyloxymethyl) pentane chloride (gemini surfactant) on the thermotropic phase behaviour of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayers with and without the presence of DNA was investigated using Fourier transformed infrared (FTIR) and circular dichroism (CD) spectroscopies, small angle scattering of synchrotron radiation and differential scanning calorimetry. With increasing concentration of surfactant in DMPC/DNA systems, a disappearance of pretransition and a decrease in the main phase transition enthalpy and temperature were observed. The increasing intensity of diffraction peaks as a function of surfactant concentration also clearly shows the ability of the surfactant to promote the organisation of lipid bilayers in the multilayer lamellar phase. PMID:23571492

  9. Two Novel Antioxidant Nonapeptides from Protein Hydrolysate of Skate (Raja porosa Muscle

    Directory of Open Access Journals (Sweden)

    Fa-Yuan Hu

    2015-04-01

    Full Text Available In the current study, the preparation conditions of neutrase hydrolysate (SMH from skate (Raja porosa muscle protein were optimized using orthogonal L9(34 tests, and R values indicated that pH was the most important factor affecting HO· scavenging activity of SMH. Under the optimum conditions of pH 7.0, enzymolysis temperature 60 °C, enzyme/substrate ratio (E/S 2%, and enzymolysis time 5 h, EC50 of SMH on HO· was 2.14 ± 0.17 mg/mL. Using ultrafiltration, gel filtration chromatography, and RP-HPLC, two novel antioxidant nonapeptides (SP-A and SP-B were isolated from SMH and their amino acid sequences were found to be APPTAYAQS (SP-A and NWDMEKIWD (SP-B with calculated molecular masses of 904.98 Da and 1236.38 Da, respectively. Both showed strong antioxidant activities. SP-A and SP-B exhibited good scavenging activities on HO· (EC50 0.390 and 0.176 mg/mL, DPPH· (EC50 0.614 and 0.289 mg/mL, and O2−· (EC50 0.215 and 0.132 mg/mL in a dose-dependent manner. SP-B was also effective against lipid peroxidation in the model system. The aromatic (2Trp, acidic (2Asp and Glu, and basic (Lys amino acid residues within the sequences of SP-B might account for its pronounced antioxidant activity. The results of this study suggested that protein hydrolysate and peptides from skate muscle might be effective as food additives for retarding lipid peroxidation occurring in foodstuffs.

  10. Two novel antioxidant nonapeptides from protein hydrolysate of skate (Raja porosa) muscle.

    Science.gov (United States)

    Hu, Fa-Yuan; Chi, Chang-Feng; Wang, Bin; Deng, Shang-Gui

    2015-04-03

    In the current study, the preparation conditions of neutrase hydrolysate (SMH) from skate (Raja porosa) muscle protein were optimized using orthogonal L9(3)4 tests, and R values indicated that pH was the most important factor affecting HO· scavenging activity of SMH. Under the optimum conditions of pH 7.0, enzymolysis temperature 60 °C, enzyme/substrate ratio (E/S) 2%, and enzymolysis time 5 h, EC50 of SMH on HO· was 2.14 ± 0.17 mg/mL. Using ultrafiltration, gel filtration chromatography, and RP-HPLC, two novel antioxidant nonapeptides (SP-A and SP-B) were isolated from SMH and their amino acid sequences were found to be APPTAYAQS (SP-A) and NWDMEKIWD (SP-B) with calculated molecular masses of 904.98 Da and 1236.38 Da, respectively. Both showed strong antioxidant activities. SP-A and SP-B exhibited good scavenging activities on HO· (EC50 0.390 and 0.176 mg/mL), DPPH· (EC50 0.614 and 0.289 mg/mL), and O2-· (EC50 0.215 and 0.132 mg/mL) in a dose-dependent manner. SP-B was also effective against lipid peroxidation in the model system. The aromatic (2Trp), acidic (2Asp and Glu), and basic (Lys) amino acid residues within the sequences of SP-B might account for its pronounced antioxidant activity. The results of this study suggested that protein hydrolysate and peptides from skate muscle might be effective as food additives for retarding lipid peroxidation occurring in foodstuffs.

  11. Interactions in mixed micellar systems of an amphoteric chelating surfactant and ionic surfactants.

    Science.gov (United States)

    Svanedal, Ida; Persson, Gerd; Norgren, Magnus; Edlund, Håkan

    2014-02-11

    Mixtures of ionic surfactants and the chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) have been examined in terms of interactions in mixed micellar systems. The amphoteric 4-C12-DTPA is zwitterionic with a negative net charge at the studied pH levels. The investigated ionic surfactants were the cationic dodecyltrimethylammonium chloride (DoTAC), the anionic sodium dodecyl sulfate (SDS), and the zwitterionic dimethyldodecylamine-N-oxide (DDAO). The surfactants all have the same hydrophobic chain lengths, and the results are evaluated in terms of headgroup interactions. 4-C12-DTPA interacts with different ionic surfactants by accepting or donating protons to the aqueous solution to increase the attractive interactions between the two surfactants; i.e., the protonation equilibrium of 4-C12-DTPA is shifted in different directions depending on whether there are predominant repulsions between positively or negatively charged groups in the mixed micelles. This was monitored by measuring pH vs concentration in the mixed systems. By measuring the pH, it was also possible to study the shift in the protonation equilibrium at increasing concentration, as the composition in the micelles approaches the composition in the total solution. Following the approach of Rubingh's regular solution theory, the interaction parameter β for mixed micelle formation was calculated from the cmc values determined by NMR diffusometry. Synergism in mixed micelle formation and negative β parameters were found in all of the investigated systems. As expected, the most negative β parameter was found in the mixture with DoTAC, followed by DDAO and SDS. The self-diffusion in the 4-C12-DTPA/DoTAC system was also discussed. The self-diffusion coefficient vs concentration plots show two distinctly different curves, depending on the surfactant that is present in excess.

  12. Surfactant Based Enhanced Oil Recovery and Foam Mobility Control

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller

    2006-09-09

    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. A mixture of two surfactants was found to be particularly effective for application in carbonate formations at low temperature. The mixture is single phase for higher salinity or calcium concentrations than that for either surfactant used alone. This makes it possible to inject the surfactant slug with polymer close to optimal conditions and yet be single phase. A formulation has been designed for a particular field application. It uses partially hydrolyzed polyacrylamide for mobility control. The addition of an alkali such as sodium carbonate makes possible in situ generation of naphthenic soap and significant reduction of synthetic surfactant adsorption. The design of the process to maximize the region of ultra-low IFT takes advantage of the observation that the ratio of soap to synthetic surfactant is a parameter in the conditions for optimal salinity. Even for a fixed ratio of soap to surfactant, the range of salinity for low IFT was wider than that reported for surfactant systems in the literature. Low temperature, forced displacement experiments in dolomite and silica sandpacks demonstrate that greater than 95% recovery of the waterflood remaining oil is possible with 0.2% surfactant concentration, 0.5 PV surfactant slug, with no alcohol. Compositional simulation of the displacement process demonstrates the role of soap/surfactant ratio on passage of the profile through the ultralow IFT region, the importance of a wide salinity range of low IFT, and the importance of the viscosity of the surfactant slug. Mobility control is essential for surfactant EOR. Foam is evaluated to improve the sweep efficiency of surfactant injected into fractured reservoirs as well as a

  13. Preparation and characterization of insulin-surfactant complexes for loading into lipid-based drug delivery systems

    DEFF Research Database (Denmark)

    Li, Ping; Nielsen, Hanne Mørck; Fano, Mathias

    2013-01-01

    and preservation of native structure. The aim of the present study was to characterize insulin after complexation with biocompatible surfactants to improve loading into lipid-based DDS. Insulin-surfactant complexes were prepared by freeze-drying with distearyldimethylammonium bromide or soybean phospholipid...... of insulin after freeze-drying from DMSO, constituting a potential generic issue with this technique for protein processing. In the specific case of insulin, the changes were found to be reversible, explaining the success of this strategy in previous studies....

  14. Cycle-Induced Flow and Surfactant Transport in an Alveolus

    Science.gov (United States)

    Wei, H. H.

    2002-11-01

    The flow and transport in an alveolus are of fundamental importance to partial liquid ventilation, surfactant transport, pulmonary drug administration, cell-cell signaling pathways and gene therapy. We model the system in which an alveolus is partially filled with liquid in the presence of surfactants. Assuming a circular interface due to sufficiently strong surface tension, we can apply two-dimensional bipolar coordinates to describe the system. We then combine analytical and numerical techniques to solve the Stokes flow and the surfactant concentration. In the absence of surfactants, there is no steady streaming because of reversibility of the Stokes flow. The presence of surfactants however induces a non-trivial cycle-averaged surfactant concentration gradient along the interface that generates steady streaming. The steady streaming patterns (e.g., number of vortices) depend on the parameters, especially on the ratio of inspiration to expiration periods (I:E ratio). Either smaller or larger I:E ratio exhibits two primary vortices but the direction of primary vortices for small I:E is opposite to large I:E. Extension to soluble surfactants is also discussed. For sufficiently high surfactant bulk concentration, the surfactant transport is sorption-controlled and soluble surfactants diminish the size of steady vortices near the alveolar opening. For the estimated steady velocity u 10-5 cm/s, the corresponding Peclet number is 10-7/ D_m. Therefore, for Dm <= 10-7 cm^2/s, the convective transport dominates.

  15. Tuning of nanoparticle-surfactant interactions in aqueous system

    Science.gov (United States)

    Kumar, Sugam; Aswal, V. K.

    2011-01-01

    The interaction of charged (anionic) silica nanoparticles with ionic and nonionic surfactants has been studied using small-angle neutron scattering (SANS). The surfactants used are anionic sodium dodecyl sulfate (SDS), cationic dodecyltrimethyl ammonium bromide (DTAB) and nonionic decaoxyethylene n-dodecylether (C12E10). The measurements are carried out at fixed concentration (1 wt%) of silica nanoparticles and with surfactant concentration varied in the range 0-2 wt%. It is found that there is no direct interaction between the nanoparticles and the surfactant (SDS) when they both are similarly charged. Both the silica nanoparticles and micelles coexist individually with no significant change in the structure of the micelles with respect to that in the pure surfactant solution. On the other hand, the presence of oppositely charged surfactant (DTAB) leads to the aggregation of silica nanoparticles even with very low surfactant concentration. The aggregation of silica nanoparticles is characterized by fractal structure and its fractal dimension remains constant with the increase in the surfactant concentration. In the case of nonionic surfactant, it interacts with the individual silica nanoparticles. The interaction is examined using two models: one that considers the surfactant layer coating on silica nanoparticles and a second one where the surface of the nanoparticles is decorated by the micelles. Contrast variation SANS measurements confirm the uniform decoration of nonionic micelles on the nanoparticles.

  16. Tuning of nanoparticle-surfactant interactions in aqueous system

    International Nuclear Information System (INIS)

    Kumar, Sugam; Aswal, V K

    2011-01-01

    The interaction of charged (anionic) silica nanoparticles with ionic and nonionic surfactants has been studied using small-angle neutron scattering (SANS). The surfactants used are anionic sodium dodecyl sulfate (SDS), cationic dodecyltrimethyl ammonium bromide (DTAB) and nonionic decaoxyethylene n-dodecylether (C 12 E 10 ). The measurements are carried out at fixed concentration (1 wt%) of silica nanoparticles and with surfactant concentration varied in the range 0-2 wt%. It is found that there is no direct interaction between the nanoparticles and the surfactant (SDS) when they both are similarly charged. Both the silica nanoparticles and micelles coexist individually with no significant change in the structure of the micelles with respect to that in the pure surfactant solution. On the other hand, the presence of oppositely charged surfactant (DTAB) leads to the aggregation of silica nanoparticles even with very low surfactant concentration. The aggregation of silica nanoparticles is characterized by fractal structure and its fractal dimension remains constant with the increase in the surfactant concentration. In the case of nonionic surfactant, it interacts with the individual silica nanoparticles. The interaction is examined using two models: one that considers the surfactant layer coating on silica nanoparticles and a second one where the surface of the nanoparticles is decorated by the micelles. Contrast variation SANS measurements confirm the uniform decoration of nonionic micelles on the nanoparticles.

  17. [ANTIMICROBIAL ACTION OF NOCARDIA VACCINII IMV B-7405 SURFACTANTS].

    Science.gov (United States)

    Pirog, T P; Beregova, K A; Savenko, I V; Shevchuk, T A; Iutynska, G O

    2015-01-01

    To study the effect of Nocardia vaccinii IMV B-7405 surfactants on some bacteria (including pathogens of genera Proteus, Staphylococcus, Enterobacter), yeast of Candida species and fungi (Aspergillus niger R-3, Fusarium culmorum T-7). The antimi- crobial properties of surfactant were determined in suspension culture by Koch method and also by index of the minimum inhibitory concentration. Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1). It is shown that the antimicrobial properties of N. vaccinii IMV B-7405 surfactant depended on the degree of purification (supernatant, solution of surfactant), concentration and exposure. Survival of Escherichia coli IEM-1 and Bacillus subtilis BT-2 (both vegetative cells and spores) after treatment for 1-2 hours with surfactants solution and the supernatant (the surfactant concentration 21 µg/ml) was 3-28%. Minimum inhibitory concentrations of N. vaccinii IMV B-7405 surfactants on studied bacteria, yeast and micromycetes were 11.5-85.0; 11.5-22.5 and 165.0-325.0 µ/ml respectively. Minimum inhibitory concentrations of N. vaccinii IMV B-7405 surfactants are comparable to those of the known microbial surfactants. The possibility of using the supernatant of culture liquid as an effective antimicrobial agent noticeably simplifies and reduces the cost of the technology of its obtaining.

  18. Next Generation Surfactants for Improved Chemical Flooding Technology

    Energy Technology Data Exchange (ETDEWEB)

    Laura Wesson; Prapas Lohateeraparp; Jeffrey Harwell; Bor-Jier Shiau

    2012-05-31

    The principle objective of this project was to characterize and test current and next generation high performance surfactants for improved chemical flooding technology, focused on reservoirs in the Pennsylvanian-aged (Penn) sands. In order to meet this objective the characteristic curvatures (Cc) of twenty-eight anionic surfactants selected for evaluation for use in chemical flooding formulations were determined. The Cc values ranged from -6.90 to 2.55 with the majority having negative values. Crude oil samples from nine Penn sand reservoirs were analyzed for several properties pertinent to surfactant formulation for EOR application. These properties included equivalent alkane carbon numbers, total acid numbers, and viscosity. The brine samples from these same reservoirs were analyzed for several cations and for total dissolved solids. Surfactant formulations were successfully developed for eight reservoirs by the end of the project period. These formulations were comprised of a tertiary mixture of anionic surfactants. The identities of these surfactants are considered proprietary, but suffice to say the surfactants in each mixture were comprised of varying chemical structures. In addition to the successful development of surfactant formulations for EOR, there were also two successful single-well field tests conducted. There are many aspects that must be considered in the development and implementation of effective surfactant formulations. Taking into account these other aspects, there were four additional studies conducted during this project. These studies focused on the effect of the stability of surfactant formulations in the presence of polymers with an associated examination of polymer rheology, the effect of the presence of iron complexes in the brine on surfactant stability, the potential use of sacrificial agents in order to minimize the loss of surfactant to adsorption, and the effect of electrolytes on surfactant adsorption. In these last four studies

  19. Interactions of Phospholipid Vesicles with Cationic and Anionic Oligomeric Surfactants.

    Science.gov (United States)

    Chen, Yao; Qiao, Fulin; Fan, Yaxun; Han, Yuchun; Wang, Yilin

    2017-07-27

    This work studied the interactions of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) with cationic ammonium surfactants and anionic sulfate or sulfonate surfactants of different oligomeric degrees, including cationic monomeric DTAB, dimeric C 12 C 3 C 12 Br 2 , and trimeric DDAD as well as anionic monomeric SDS, dimeric C 12 C 3 C 12 (SO 3 ) 2 , and trimeric TED-(C 10 SO 3 Na) 3 . The partition coefficient P of these surfactants between the DOPC vesicles and water was determined with isothermal titration microcalorimetry (ITC) by titrating concentrated DOPC solution into the monomer solution of these surfactants. It was found that the P value increases with the increase of the surfactant oligomeric degree. Moreover, the enthalpy change and the Gibbs free energy for the transition of these surfactants from water into the DOPC bilayer become more negative with increasing the oligomeric degree. Meanwhile, the calcein release experiment proves that the surfactant with a higher oligomeric degree shows stronger ability of changing the permeability of the DOPC vesicles. Furthermore, the solubilization of the DOPC vesicles by these oligomeric surfactants was studied by ITC, turbidity, and dynamic light scattering, and thus the phase boundaries for the surfactant/lipid mixtures have been determined. The critical surfactant to lipid ratios for the onset and end of the solubilization for the DOPC vesicles derived from the phase boundaries decrease remarkably with increasing the oligomeric degree. Overall, the surfactant with a larger oligomerization degree shows stronger ability in incorporating into the lipid bilayer, altering the membrane permeability and solubilizing lipid vesicles, which provides comprehensive understanding about the effects of structure and shape of oligomeric surfactant molecules on lipid-surfactant interactions.

  20. Moving liquid surfactant as a way of assessing the properties of surfactant, liquids and surfaces

    Science.gov (United States)

    Titov, A. O.; Titov, O. P.; Titov, M. O.; Karbainov, A. N.

    2011-04-01

    In the study of surface phenomena of the main and only instrumentally-defined parameters are surface tension and wetting angle, including in the field of nanotechnology. These indicators were introduced more than 200 years ago, and any new inventions in this field was no more. The university developed a new method and device for determining the surface activity. The basis of the method and device is the use of video cameras to record the droplet size and changes on the surface of the liquid layer of known thickness from the impact of drops of surfactant (surfactant). Committed changes are then processed using computer software and calculated parameters, which can be characterized by a surfactant and surface properties, which is fluid and very liquid. Determine the surface tension or contact angle is not necessary. Measures of surface activity using the method and device are: The amount of fluid that can move one kilogram of surfactant. The value of this index varies from tens of nanometers to hundreds of thousands of units. The indicator can be converted to energy units, joules. The amount of fluid confined by a surface per unit time is calculated based on the first indicator, complements the characterization of surfactant and may be an indicator of surface characteristics and fluid. Propagation speed of the capillary and microwaves. This indicator complements the first two.

  1. Hydrogels of sodium alginate in cationic surfactants: Surfactant dependent modulation of encapsulation/release toward Ibuprofen.

    Science.gov (United States)

    Jabeen, Suraya; Chat, Oyais Ahmad; Maswal, Masrat; Ashraf, Uzma; Rather, Ghulam Mohammad; Dar, Aijaz Ahmad

    2015-11-20

    The interaction of cetyltrimethylammoium bromide (CTAB) and its gemini homologue (butanediyl-1,4-bis (dimethylcetylammonium bromide), 16-4-16 with biocompatible polymer sodium alginate (SA) has been investigated in aqueous medium. Addition of K2CO3 influences viscoelastic properties of surfactant impregnated SA via competition between electrostatic and hydrophobic interactions. Viscosity of these polymer-surfactant systems increases with increase in concentration of K2CO3, and a cryogel is formed at about 0.5M K2CO3 concentration. The thermal stability of gel (5% SA+0.5M K2CO3) decreases with increase in surfactant concentration, a minimum is observed with increase in 16-4-16 concentration. The impact of surfactant addition on the alginate structure vis-à-vis its drug loading capability and release thereof was studied using Ibuprofen (IBU) as the model drug. The hydrogel with 16-4-16 exhibits higher IBU encapsulation and faster release in comparison to the one containing CTAB. This higher encapsulation-cum-faster release capability has been related to micelle mediated solubilization and greater porosity of the hydrogel with gemini surfactant. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Identification of novel fluorinated surfactants in aqueous film forming foams and commercial surfactant concentrates.

    Science.gov (United States)

    D'Agostino, Lisa A; Mabury, Scott A

    2014-01-01

    Recent studies comparing the results of total organofluorine-combustion ion chromatography (TOF-CIC) to targeted analysis of perfluoroalkyl and polyfluoroalkyl substances (PFASs) by liquid chromatography tandem mass spectrometry (LC-MS/MS) have shown that a significant yet variable portion of the total organofluorine in environmental and biological samples is in the form of unknown PFASs. A portion of this unknown organofluorine likely originates in proprietary fluorinated surfactants not included in LC-MS/MS analyses and not fully characterized by the environmental science community, which may enter the environment through use in aqueous film forming foams (AFFFs) for firefighting. Contamination of water, biota, and soils with various PFASs due to AFFF deployment has been documented. Ten fluorinated AFFF concentrates, 9 of which were obtained from fire sites in Ontario, Canada, and two commercial fluorinated surfactant concentrates were characterized in order to identify novel fluorinated surfactants. Mixed-mode ion exchange solid phase extraction (SPE) fractionated fluorinated surfactants based on ionic character. High resolution mass spectrometry assigned molecular formulas to fluorinated surfactant ions, while collision induced dissociation (CID) spectra assisted structural elucidation. LC-MS/MS detected isomers and low abundance fluorinated chain lengths. In total, 12 novel and 10 infrequently reported PFAS classes were identified in fluorinated chain lengths from C3 to C15 for a total of 103 compounds. Further research should examine the environmental fate and toxicology of these PFASs, especially their potential as perfluoroalkyl acid (PFAA) precursors.

  3. O/W emulsions stabilised by both low molecular weight surfactants and colloidal particles: The effect of surfactant type and concentration.

    Science.gov (United States)

    Pichot, R; Spyropoulos, F; Norton, I T

    2010-12-01

    The stability against coalescence of O/W emulsions in the presence of both surfactants and colloidal particles was investigated. In particular the effect of the surfactant type and concentration in these emulsifier mixtures on the O/W emulsions' stability was studied. Two types of surfactants were selected; those that have the ability to stabilise O/W emulsions on their own (O/W surfactants) and those that cannot (W/O surfactants). Tween 60 and Sodium Caseinate were selected as the O/W surfactants and lecithin as the W/O surfactant. Oil-in-water emulsions prepared with both particles and any of the three surfactants were stable against coalescence but, depending on the type of surfactant, the behaviour of the systems was found to depend on surfactant concentration. The droplet sizes of emulsions stabilised by mixed emulsifier systems containing low concentrations of O/W surfactants (Tween 60 or Sodium Caseinate) were smaller than those solely stabilised by either the surfactant or particles alone. At intermediate O/W surfactants concentrations, the droplet sizes of the emulsions increased. Further increases in the O/W surfactants' concentration, resulted in the complete removal of particles from the interface with the system now behaving as a surfactant-only stabilised emulsion. The behaviour of emulsions stabilised by emulsifier mixtures containing W/O surfactants was not dependent on the concentration of surfactant: no removal of particles was observed. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Interactions of bovine serum albumin with cationic imidazolium and quaternary ammonium gemini surfactants: effects of surfactant architecture.

    Science.gov (United States)

    Zhou, Ting; Ao, Mingqi; Xu, Guiying; Liu, Teng; Zhang, Juan

    2013-01-01

    The interactions of BSA with a series of cationic imidazolium gemini surfactants ([C(n)-s-C(n)im]Br(2), n=10, 12, 14, s=2, 4, 6), quaternary ammonium surfactants (C(12)C(2)C(12)), and their corresponding monomers ([C(12)mim]Br and DTAB) are investigated by fluorescence using pyrene as a molecular probe, synchronous fluorescence, circular dichroism (CD), and UV-visible absorption spectra. These surfactants are used to elucidate the effects of surfactant hydrophilic head group, spacer length, and hydrophobic chain length on the conformation of BSA. The results of fluorescence spectra and CD show that the imidazolium gemini surfactants with shorter spacers or with longer hydrophobic chains have a larger effect on BSA unfolding, and the imidazolium gemini surfactant interacts with BSA more strongly than its corresponding monomer and the quaternary ammonium gemini surfactant. These conclusions have been confirmed by the binding constants (K(a)) and binding sites (n) for the BSA/surfactant system. Stern-Volmer quenching constants K(SV) of cationic surfactants binding to BSA are obtained, indicating that the probable quenching mechanism is initiated by ground-state complex formation rather than by dynamic collision. Moreover, the synchronous fluorescence spectra show that the surfactants mainly interact with tryptophan residues of BSA. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. On the rheology of mixed systems of hydrophobically modified polyacrylate microgels and surfactants: Role of the surfactant architecture.

    Science.gov (United States)

    Alves, Luís; Lindman, Björn; Klotz, Björn; Böttcher, Axel; Haake, Hans-Martin; Antunes, Filipe E

    2018-03-01

    The rheological control of suspensions is of key interest in the formulation design. A chemically cross-linked hydrophobically modified poly(acrylic acid) (HMCL-PAA), used as rheology modifier, is pH sensitive and shows swelling behavior above a critical pH due to the ionization of the acrylic acid groups. At low pH, HMCL-PAA suspensions are liquid and turbid. The binding of surfactants to HMCL-PAA, at low pH conditions, can result in significant changes on rheology and transparency of the polymeric suspensions, due to the swelling of the microgel particles. The influence of surfactants addition on the rheological properties and transparency of HMCL-PAA suspensions was determined. A systematic study was performed using different types of surfactants (ionic, non-ionic and zwitterionic). The gelation efficiency of HMCL-PAA suspensions at low pH is strongly dependent on surfactant architecture: ionic surfactants are found to be much more efficient than non-ionic or zwitterionic surfactants. Ionic surfactants lead to a liquid-to-gel transition accompanied by an increase of transparency of the suspensions. Among the ionic surfactants, anionics show stronger interactions with the polymer. Also the surfactant hydrophobicity is relevant; the more hydrophobic the surfactant, the stronger is the binding to the polymer and thus the larger the particle swelling. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Equilibrium and nonequilibrium behaviour of surfactant systems

    OpenAIRE

    Reissig, Louisa

    2010-01-01

    In binary systems, surfactant molecules can self-assemble into a large variety of structures depending on their chemical structure, concentration and temperature. The properties and stability of the phases, their coexistence regions and the formation of metastable structures is of great importance not only for fundamental understanding, but also for applications in many fields including industry and medicine. This thesis presents studies of the equilibrium and non-equilibrium b...

  7. Deleted in Malignant Brain Tumors 1 (DMBT1 is present in hyaline membranes and modulates surface tension of surfactant

    Directory of Open Access Journals (Sweden)

    Griese Matthias

    2007-10-01

    Full Text Available Abstract Background Deleted in Malignant Brain Tumors 1 (DMBT1 is a secreted scavenger receptor cysteine-rich protein that binds various bacteria and is thought to participate in innate pulmonary host defense. We hypothesized that pulmonary DMBT1 could contribute to respiratory distress syndrome in neonates by modulating surfactant function. Methods DMBT1 expression was studied by immunohistochemistry and mRNA in situ hybridization in post-mortem lungs of preterm and full-term neonates with pulmonary hyaline membranes. The effect of human recombinant DMBT1 on the function of bovine and porcine surfactant was measured by a capillary surfactometer. DMBT1-levels in tracheal aspirates of ventilated preterm and term infants were determined by ELISA. Results Pulmonary DMBT1 was localized in hyaline membranes during respiratory distress syndrome. In vitro addition of human recombinant DMBT1 to the surfactants increased surface tension in a dose-dependent manner. The DMBT1-mediated effect was reverted by the addition of calcium depending on the surfactant preparation. Conclusion Our data showed pulmonary DMBT1 expression in hyaline membranes during respiratory distress syndrome and demonstrated that DMBT1 increases lung surface tension in vitro. This raises the possibility that DMBT1 could antagonize surfactant supplementation in respiratory distress syndrome and could represent a candidate target molecule for therapeutic intervention in neonatal lung disease.

  8. Dynamics of contracting surfactant-covered filaments

    Science.gov (United States)

    Kamat, Pritish; Thete, Sumeet; Xu, Qi; Basaran, Osman

    2013-11-01

    When drops are produced from a nozzle, a thin liquid thread connects the primary drop that is about to form to the rest of the liquid in the nozzle. Often, the thread becomes disconnected from both the primary drop and the remnant liquid mass hanging from the nozzle and thereby gives rise to a free filament. Due to surface tension, the free filament then contracts or recoils. During recoil, the filament can either contract into a single satellite droplet or break up into several small satellites. Such satellite droplets are undesirable in applications where they can, for example, cause misting in a manufacturing environment and mar product quality in ink-jet printing. In many applications, the filaments are coated with a monolayer of surfactant. In this work, we study the dynamics of contraction of slender filaments of a Newtonian fluid that are covered with a monolayer of surfactant when the surrounding fluid is a passive gas. Taking advantage of the fact that the filaments are long and slender, we use a 1D-slender-jet approximation of the governing system of equations consisting of the Navier-Stokes system and the convection-diffusion equation for surfactant transport. We solve the 1D system of equations by a finite element based numerical method.

  9. Influence of metacide - surfactant complexes on agricultural crops

    Directory of Open Access Journals (Sweden)

    Orynkul Esimova

    2014-12-01

    Full Text Available The complexes based on surfactants and polyhexamethyleneguanidine hydrochloride (metacide are important for agriculture. This paper considers compositions of known bactericidal metacide with different surfactants: anionic surfactant sodium dodecylsulphate (DDSNa and nonionic surfactant Tween 80 (monooleate of oxyethylenated anhydrosorbitols. The effect of individual components and associates of metacide and surfactants on productivity and infection of cereals was studied. According to the study, the highest productivity and infection rate were shown by the associate of metacide and Tween-80. At concentration of Tween-80 in aqueous solution equal to 0.001% in combination with metacide, efficiency was 98% at 0% infection. The surface tension and the wetting of metacide, DDSNa, Tween-80, and associates of metacide with surfactants were studied. In comparison with individual components, metacide-DDSNa and metacide-Tween-80 associates have higher surface activity.

  10. Antibacterial Activities of Surfactants in the Laundry Detergents and Isolation of the Surfactant Resistant Aquatic Bacteria.

    Science.gov (United States)

    Maehara, Yoko; Miyoshi, Shin-Ichi

    2017-01-01

     Linear alkylbenzene sulfonate (LAS) and polyoxyethylene lauryl ether (POLE) are major surfactants contained in the laundry detergents. In the present study, the antibacterial activities of the surfactants to aquatic microorganisms were compared. When freshwater samples from a small river in Okayama city were treated with each of the surfactants, only LAS showed the significant antibacterial activity. Several strains, which survived after the treatment with 2.0% LAS, were isolated and identified by sequencing of 16S rDNA. All strains were classified into the family Enterobacteriaceae. However, this family was not a major member of the aquatic microflora, suggesting that the bacteria in Enterobacteriaceae have a common property of LAS-resistance in the river water.

  11. The Role of Surfactant in Respiratory Distress Syndrome

    OpenAIRE

    Ma, Christopher Cheng-Hwa; Ma, Sze

    2012-01-01

    The key feature of respiratory distress syndrome (RDS) is the insufficient production of surfactant in the lungs of preterm infants. As a result, researchers have looked into the possibility of surfactant replacement therapy as a means of preventing and treating RDS. We sought to identify the role of surfactant in the prevention and management of RDS, comparing the various types, doses, and modes of administration, and the recent development. A PubMed search was carried out up to March 2012 u...

  12. Investigation of Polymer-Surfactant and Polymer-Drug-Surfactant Miscibility for Solid Dispersion.

    Science.gov (United States)

    Gumaste, Suhas G; Gupta, Simerdeep Singh; Serajuddin, Abu T M

    2016-09-01

    In a solid dispersion (SD), the drug is generally dispersed either molecularly or in the amorphous state in polymeric carriers, and the addition of a surfactant is often important to ensure drug release from such a system. The objective of this investigation was to screen systematically polymer-surfactant and polymer-drug-surfactant miscibility by using the film casting method. Miscibility of the crystalline solid surfactant, poloxamer 188, with two commonly used amorphous polymeric carriers, Soluplus® and HPMCAS, was first studied. Then, polymer-drug-surfactant miscibility was determined using itraconazole as the model drug, and ternary phase diagrams were constructed. The casted films were examined by DSC, PXRD and polarized light microscopy for any crystallization or phase separation of surfactant, drug or both in freshly prepared films and after exposure to 40°C/75% RH for 7, 14, and 30 days. The miscibility of poloxamer 188 with Soluplus® was <10% w/w, while its miscibility with HPMCAS was at least 30% w/w. Although itraconazole by itself was miscible with Soluplus® up to 40% w/w, the presence of poloxamer drastically reduced its miscibility to <10%. In contrast, poloxamer 188 had minimal impact on HPMCAS-itraconazole miscibility. For example, the phase diagram showed amorphous miscibility of HPMCAS, itraconazole, and poloxamer 188 at 54, 23, and 23% w/w, respectively, even after exposure to 40°C/75% RH for 1 month. Thus, a relatively simple and practical method of screening miscibility of different components and ultimately physical stability of SD is provided. The results also identify the HPMCAS-poloxamer 188 mixture as an optimal surface-active carrier system for SD.

  13. Comparative effects of bronchoalveolar lavage with saline, surfactant, or perfluorocarbon in experimental meconium aspiration syndrome.

    Science.gov (United States)

    Rey-Santano, Carmen; Mielgo, Victoria E; Gastiasoro, Elena; Alvarez-Diaz, Francisco J; Lafuente, Hector; Valls-i-Soler, Adolfo; Murgia, Xabier

    2012-05-01

    Today, in meconium aspiration syndrome, treatment focuses on bronchoalveolar lavage, because it removes meconium and proinflammatory factors from airways. This technique might be more effective if different solutions were used such as saline solution, a protein-free surfactant, or a perfluorocarbon, because these would be less inhibited by meconium proteins. Pulmonary physiology research unit, Cruces Hospital. Prospective, randomized study. We studied 24 lambs (meconium (3-5 mL/Kg) and were randomly assigned to one of the following groups (n = 6): control: only continuous mechanical ventilation; saline bronchoalveolar lavage: bronchoalveolar lavage with 30 mL/kg of saline solution; dilute surfactant bronchoalveolar lavage: bronchoalveolar lavage with 32 mL/kg of diluted surfactant (lucinactant, 10 mg/mL); or perfluorocarbon bronchoalveolar lavage: bronchoalveolar lavage with 30 mL/kg of perfluorocarbon. Blood gases, cardiovascular parameters, and pulmonary mechanics were assessed. Meconium instillation produced severe hypoxia, hypercapnia, acidosis, and pulmonary hypertension with impairment of pulmonary mechanics (p meconium aspiration syndrome, bronchoalveolar lavage with diluted lucinactant is an effective therapy producing significant improvements in gas exchange, pulmonary hypertension, and pulmonary mechanics. In addition, bronchoalveolar lavage with perfluorocarbon appears to confer some advantages over lavage with equal volumes of saline or no lavage.

  14. Nanoparticle-enabled delivery of surfactants in porous media.

    Science.gov (United States)

    Nourafkan, Ehsan; Hu, Zhongliang; Wen, Dongsheng

    2018-06-01

    The adsorption of surfactants on the reservoir rocks surface is a serious issue in many energy and environment related areas. Learning from the concept of drug delivery in the nano-medicine field, this work proposes and validates the concept of using nanoparticles to deliver a mixture of surfactants into a porous medium. TiO 2 nanoparticles (NPs) are used as carriers for a blend of surfactants mixtures including anionic alkyl aryl sulfonic acid (AAS) and nonionic alcohol ethoxylated (EA) at the optimum salinity and composition conditions. The transport of NPs through a core sample of crushed sandstone grains and the adsorption of surfactants are evaluated. By using TiO 2 NPs, the adsorption of surfactant molecules can be significantly reduced, i.e. half of the initial adsorption value. The level of surfactant adsorption reduction is related to the NPs transport capability through the porous medium. An application study shows that comparing to surfactant flooding alone, the total oil recovery can be increased by 7.81% of original oil in place (OOIP) by using nanoparticle bonded surfactants. Such work shows the promise of NP as an effective surfactant carrier for sandstone reservoirs, which could have many potential applications in enhanced oil recovery (EOR) and environmental remediation. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Fractal Aggregation in Silica Nanoparticle and Surfactant Composites

    Science.gov (United States)

    Kumar, Sugam; Aswal, V. K.

    2011-07-01

    The role of cationic surfactant on particle aggregation of anionic silica nanoparticles has been studied by small-angle neutron scattering (SANS). We show that the aggregation is characterized by the fractal structure. The fractal dimension is found to be same irrespective of varying the surfactant and its concentration. These results are explained on the basis of that the aggregation of particles mediated by the oppositely charged surfactant micelles between them and governed by the diffusion limited aggregation. Both adsorbed and free micelles coexists and the number of adsorbed micelles does not change with varying surfactant concentration however decreases with the increase in the size of the micelle.

  16. Surfactants have multi-fold effects on skin barrier function.

    Science.gov (United States)

    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.

  17. Surfactant Effects on Lipid-Based Vesicles Properties.

    Science.gov (United States)

    Bnyan, Ruba; Khan, Iftikhar; Ehtezazi, Touraj; Saleem, Imran; Gordon, Sarah; O'Neill, Francis; Roberts, Matthew

    2018-01-11

    Understanding the effect of surfactant properties is critical when designing vesicular delivery systems. This review evaluates previous studies to explain the influence of surfactant properties on the behavior of lipid vesicular systems, specifically their size, charge, stability, entrapment efficiency, pharmacokinetics, and pharmacodynamics. Generally, the size of vesicles decreases by increasing the surfactant concentration, carbon chain length, the hydrophilicity of the surfactant head group, and the hydrophilic-lipophilic balance. Increasing surfactant concentration can also lead to an increase in charge, which in turn reduces vesicle aggregation and enhances the stability of the system. The vesicles' entrapment efficiency not only depends on the surfactant properties but also on the encapsulated drug. For example, the encapsulation of a lipophilic drug could be enhanced by using a surfactant with a low hydrophilic-lipophilic balance value. Moreover, the membrane permeability of vesicles depends on the surfactant's carbon chain length and transition temperature. In addition, surfactants have a clear influence on pharmacokinetics and pharmacodynamics such as sustaining drug release, enhancing the circulation time of vesicles, improving targeting and cellular uptake. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  18. Inactivation of Herpes Simplex Viruses by Nonionic Surfactants

    Science.gov (United States)

    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

  19. Perfluorinated surfactants in surface and drinking waters.

    Science.gov (United States)

    Skutlarek, Dirk; Exner, Martin; Färber, Harald

    2006-09-01

    In this paper recent results are provided of an investigation on the discovery of 12 perfluorinated surfactants (PS) in different surface and drinking waters (Skutlarek et al. 2006 a, Skutlarek et al. 2006 b). In the last years, many studies have reported ubiquitous distribution of this group of perfluorinated chemicals, especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in the environment, particularly in wildlife animal and human samples (Giesy and Kannan 2001, Houde et al. 2006, Prevedouros et al. 2006). Perfluorinated surfactants (e.g. PFOS and PFOA) have shown different potentials for reproductory interference and carcinogenity in animal experiments as well as partly long half-lives in humans (Guruge et al. 2006, FSA UK 2006a, FSA UK 2006b, 3M 2005, OECD 2002, Yao and Zhong 2005). They possess compound-dependent extreme recalcitrance against microbiological and chemical degradation and, in addition, they show variable potentials for bioaccumulation in animals and humans (Houde et al. 2006). Surface and drinking water samples were collected from different sampling sites: Surface waters: samples taken from the rivers Rhine, Ruhr, Moehne and some of their tributaries. Further samples were taken from the Rhine-Herne-Canal and the Wesel-Datteln-Canal. Drinking waters: samples taken in public buildings of the Rhine-Ruhr area. After sample clean-up and concentration by solid-phase extraction, the perfluorinated surfactants were determined using HPLC-MS/MS. All measured concentrations (sum of seven mainly detected components) in the Rhine river and its main tributaries (mouths) were determined below 100 ng/L. The Ruhr river (tributary of the Rhine) showed the highest concentration (94 ng/L), but with a completely different pattern of components (PFOA as major component), as compared with the other tributaries and the Rhine river. Further investigations along the Ruhr river showed remarkably high concentrations of PS in the upper reaches of

  20. Influences and mechanisms of surfactants on pyrene biodegradation based on interactions of surfactant with a Klebsiella oxytoca strain.

    Science.gov (United States)

    Zhang, Dong; Zhu, Lizhong; Li, Feng

    2013-08-01

    Surfactant-enhanced bioremediation has been proposed as a promising technology for the treatment of organic polluted soils; however its application has been hindered by the controversial influences and mechanisms of surfactants on the biodegradation of hydrophobic organic compounds. To address this problem, effects of five surfactants on the sorption and biodegradation of pyrene by Klebsiella oxytoca PYR-1, as well as their interactions with bacterial cell surface and membrane lipids were investigated. We found that surfactants enhanced or inhibited pyrene biodegradation depending on their effects on the sorption of pyrene onto bacterial cell, which occurred mainly through modifying cell surface hydrophobicity (such as Tween series surfactants) or disrupting bacterial membrane (such as Triton X-100), respectively. A relatively high positive correlation (Psurfactant, indicating that surfactant-induced sorption played the dominant role during pyrene biodegradation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. TOXICITY COMPARISON OF BIOSURFACTANTS AND SYNTHETIC SURFACTANTS USED IN OIL SPILL REMEDIATION TO TWO ESTUARINE SPECIES

    Science.gov (United States)

    The relative environmental toxicities of synthetic and biogenic surfactants used in oil spill remediation efforts are not well understood. Acute and chronic toxicities of three synthetic surfactants and three microbially produced surfactants were determined and compared in this s...

  2. Influence of pulmonary surfactant on in vitro bactericidal activities of amoxicillin, ceftazidime, and tobramycin

    NARCIS (Netherlands)

    A. van 't Veen (Annemarie); J.W. Mouton (Johan); D.A.M.P.J. Gommers (Diederik); J.A.J.W. Kluytmans (Jan); P. Dekkers; B.F. Lachmann (Burkhard)

    1995-01-01

    textabstractThe influence of a natural pulmonary surfactant on antibiotic activity was investigated to assess the possible use of exogenous surfactant as a vehicle for antibiotic delivery to the lung. The influence of surfactant on the bactericidal activity of

  3. High postoperative serum levels of surfactant type B as novel prognostic markers for congenital heart surgery

    Directory of Open Access Journals (Sweden)

    Onur Is?k

    2014-04-01

    Full Text Available Objective: Congenital heart diseases are observed in 5 to 8 of every 1000 live births. The presence of a valuable biomarker during the surgical periods may aid the clinician in a more accurate prognosis during treatment. Methods: For this reason, surfactant protein B plasma levels may help to evaluate patients with cardiac problems diminishing the alveolocapillary membrane stability. In this study, plasma levels of this biomarker were measured in the preoperative and postoperative periods. This study was conducted to detect the differences between pulmonary hypertensive and normotensive patients. The differences before and after cardiopulmonary bypass were examined. Results: The differences in cardiopulmonary bypass time, cross-clamp time , inotropic support dose, and duration of intensive care of patients with and without pulmonary hypertensive were found to be statistically significant (P<0.05. The results revealed that this pathophysiological state was related to other variables that were studied. We believe that the differences in preoperative and postoperative SPB levels could be attributed to alveolocapillary membrane damage and alveolar surfactant dysfunction. We found that this pathophysiological condition was significantly associated with postoperative parameters. Conclusion: The findings of the current study showed that surfactant protein B was present in the blood of patients with a congenital heart disease during the preoperative period. Long by-pass times may exert damage to the alveolocapillary membrane in patients with pulmonary hypertension and preoperative heart failure, and it is recommended to keep the option of surfactant therapy in mind during the postoperative course at the intensive care unit before preparing the patients for extubation.

  4. Hexafluoroisopropanol-induced catanionic-surfactants-based coacervate extraction for analysis of lysozyme.

    Science.gov (United States)

    Xu, Jia; Niu, Manli; Xiao, Yuxiu

    2017-02-01

    A coacervate extraction method, based on hexafluoroisopropanol (HFIP)-induced catanionic surfactants and coupled with a back-extraction procedure, was developed for separation and purification of proteins, using sodium dodecyl sulfate (SDS) and dodecyltrimethyl ammonium bromide (DTAB) as representative catanionic surfactants and lysozyme as a model protein. After the coacervate extraction and back extraction, the obtained lysozyme solutions were examined in terms of quantitative analysis by capillary electrophoresis, bacteriolytic activity, and circular dichroism (CD). The effects of several parameters including back-extraction solvent, HFIP content, total surfactant concentration, and SDS/DTAB molar ratio were investigated in detail on the extraction efficiency and activity of lysozyme. Under the optimized extraction conditions (66 mM KH 2 PO 4 buffer with pH 6.2 as back-extraction solvent, SDS/DTAB molar ratio = 1:1 mol/mol, total surfactant concentration = 30 mM, HIFP concentration = 8 % v/v), the extraction recovery was 89.8 % (±4.7, n = 3), limit of detection was 2.2 (±0.3, n = 3) μg mL -1 , and meanwhile nearly 65 % of native lysozyme activity was retained. In addition, the activity and CD assays showed that SDS/DTAB molar ratio had a significant influence on the activity and structure of lysozyme after extraction. The DTAB-rich extraction systems, in which the DTAB mole fraction was equal to or larger than 70 %, could keep the activity and structure of lysozyme almost in the native state. Graphical Abstract Procedure of HFIP-induced SDS/DTAB coacervate extraction and back extraction of lysozyme.

  5. Surfactant-Solvent Interaction Effects on the Micellization of Cationic Surfactants in a Carboxylic Acid-Based Deep Eutectic Solvent.

    Science.gov (United States)

    Sanchez-Fernandez, Adrian; Hammond, Oliver S; Jackson, Andrew J; Arnold, Thomas; Doutch, James; Edler, Karen J

    2017-12-19

    Deep eutectic solvents have been demonstrated to support amphiphile self-assembly, providing potential alternatives as structure-directing agents in the synthesis of nanostructures, and drug delivery. Here we have expanded on this recent research to investigate the self-assembly of alkyltrimethylammonium bromide surfactants in choline chloride:malonic acid deep eutectic solvent and mixtures of the solvent with water. Surface tension and small-angle neutron scattering were used to determine the behavior of the amphiphiles. Surfactants were found to remain active in the solvent, and surface tension measurements revealed changes in the behavior of the surfactants with different levels of hydration. Small-angle neutron scattering shows that in this solvent the micelle shape depends on the surfactant chain length, varying from globular micelles (aspect ratio ∼2) for short chain surfactants to elongated micelles (aspect ratio ∼14) for long chain surfactants even at low surfactant concentration. We suggest that the formation of elongated micelles can be explained through the interaction of the solvent with the surfactant headgroup, since ion-ion interactions between surfactant headgroups and solvent may modify the morphology of the micelles. The presence of water in the deep eutectic solvents promotes an increase in the charge density at the micelle interface and therefore the formation of less elongated, globular micelles.

  6. Surfactant-enhanced control of track-etch pore morphology

    International Nuclear Information System (INIS)

    Apel', P.Yu.; Blonskaya, I.V.; Didyk, A.Yu.; Dmitriev, S.N.; Orelovich, O.L.; Samojlova, L.I.; Vutsadakis, V.A.; Root, D.

    2000-01-01

    The influence of surfactants on the process of chemical development of ion tracks in polymers is studied. Based on the experimental data, a mechanism of the surfactant effect on the track-etch pore morphology is proposed. In the beginning of etching the surfactant is adsorbed on the surface and creates a layer that is quasi-solid and partially protects the surface from the etching agent. However, some etchant molecules diffuse through the barrier and react with the polymer surface. This results in the formation of a small hole at the entrance to the ion track. After the hole has attained a few annometers in diameter, the surfactant molecules penetrate into the track and cover its walls. Further diffusion of the surfactant into the growing pore is hindered. The adsorbed surfactant layer is not permeable for large molecules. In contrast, small alkali molecules and water molecules diffuse into the track and provide the etching process enlarging the pore. At this stage the transport of the surfactant into the pore channel can proceed only due to the lateral diffusion in the adsorbed layer. The volume inside the pore is free of surfactant molecules and grows at a higher rate than pore entrance. After a more prolonged etching the bottle-like (or 'cigar-like') pore channels are formed. The bottle-like shape of the pore channels depends on the etching conditions such as alkali and surfactant concentration, temperature, and type of the surfactant. The use of surfactants enables one to produce track-etch membranes with improved flow rate characteristics compared with those having cylindrical pores with the same nominal pore diameters

  7. Identifying the Imprint of Surfactant Stabilisation in Whitecap Foam Evolution

    Science.gov (United States)

    Callaghan, A. H.; Deane, G. B.; Stokes, D.

    2016-02-01

    Surfactants are ubiquitous in the world's oceans and can affect climatically-relevant processes such as air-sea gas exchange, sea spray aerosol (SSA) flux, and air-sea momentum transfer. Surfactants are amphiphilic and help form the physically and chemically distinct ocean surface microlayer (SML), however, the spatial distribution, concentration and composition of the SML is not well understood, especially under conditions of vigorous wave breaking. Like the SML, breaking waves also influence physical exchange processes at the air-sea interface, and oceanic whitecap foam coverage is commonly used to quantify bubble-mediated exchange processes. However, surfactants can increase the lifetime of foam over clean water conditions, potentially complicating the use of whitecap coverage to parameterise air-sea gas exchange and SSA production flux. A better understanding of how surfactants affect the evolution of whitecap foam is needed to improve whitecap parameterisations of bubble-mediated processes, and may also provide a remote sensing approach to map the spatial distribution of surfactants at the water surface. Here we present results from a laboratory study that looked at whitecap foam evolution in "clean" and "surfactant-added" seawater regimes. We find that the whitecap foam area growth timescale is largely insensitive to the presence of surfactants, but that surfactant stabilization of whitecap foam becomes important during the whitecap foam area decay phase. The timescale at which this occurs appears to be consistent for breaking waves of different scale and intensity. A simple method is then used to isolate the surfactant signal and derive an equivalent "clean" seawater foam decay time for the whitecaps in the "surfactant-added" regime. The method is applied to oceanic whitecaps and results compared to the laboratory whitecaps from the "clean" and "surfactant-added" regimes.

  8. MOLECULAR-DYNAMICS SIMULATIONS OF CARBOHYDRATE-BASED SURFACTANTS IN SURFACTANT WATER OIL SYSTEMS

    NARCIS (Netherlands)

    VANBUUREN, AR; BERENDSEN, HJC

    Molecular dynamics simulations of two monolayers of carbohydrate-based surfactants (decyl alpha-glucoside and decyl beta-glucoside) at the interface between liquid decane and liquid water have been performed with the purpose to study the properties of these monolayers on a molecular and atomic

  9. RELATION BETWEEN SURFACTANT STRUCTURE AND PROPERTIES OF SPHERICAL MICELLES - 1-ALKYL-4-ALKYLPYRIDINIUM HALIDE SURFACTANTS

    NARCIS (Netherlands)

    NUSSELDER, JJH; ENGBERTS, JBFN

    1991-01-01

    This paper describes a detailed study of the properties of spherical micelles formed from 18 1-alkyl-4-alkylpyridinium iodides. Structural variations in the surfactants include (i) branching of the 4-alkyl chain while keeping the number of carbons in the chain invariant and (ii) variation of the

  10. Neonatal varicella pneumonia, surfactant replacement therapy

    Directory of Open Access Journals (Sweden)

    Mousa Ahmadpour-kacho

    2015-12-01

    Full Text Available Background: Chickenpox is a very contagious viral disease that caused by varicella-zoster virus, which appears in the first week of life secondary to transplacental transmission of infection from the affected mother. When mother catches the disease five days before and up to two days after the delivery, the chance of varicella in neonate in first week of life is 17%. A generalized papulovesicular lesion is the most common clinical feature. Respiratory involvement may lead to giant cell pneumonia and respiratory failure. The mortality rate is up to 30% in the case of no treatment, often due to pneumonia. Treatment includes hospitalization, isolation and administration of intravenous acyclovir. The aim of this case report is to introduce the exogenous surfactant replacement therapy after intubation and mechanical ventilation for respiratory failure in neonatal chickenpox pneumonia and respiratory distress. Case Presentation: A seven-day-old neonate boy was admitted to the Neonatal Intensive Care Unit at Amirkola Children’s Hospital, Babol, north of Iran, with generalized papulovesicular lesions and respiratory distress. His mother has had a history of Varicella 4 days before delivery. He was isolated and given supportive care, intravenous acyclovir and antibiotics. On the second day, he was intubated and connected to mechanical ventilator due to severe pneumonia and respiratory failure. Because of sever pulmonary involvement evidenced by Chest X-Ray and high ventilators set-up requirement, intratracheal surfactant was administered in two doses separated by 12 hours. He was discharged after 14 days without any complication with good general condition. Conclusion: Exogenous surfactant replacement therapy can be useful as an adjunctive therapy for the treatment of respiratory failure due to neonatal chickenpox.

  11. Surfactant-like properties of extractants molecules

    International Nuclear Information System (INIS)

    Bauduin, Pierre; Bauer, Caroline; Bance, Amelie; Gassin, Gaelle; Diat, Olivier; Zemb, Thomas

    2012-01-01

    Solvent extraction is based on aqueous phase/oil/extractant systems with the extractant being exclusively soluble in oil and which perform the extraction of ions (or salts) from the aqueous phase. The present contribution aims at investigating solvent extraction systems using a classical approach in surfactant science. The discussion is based on the description of the phase diagrams topology and on molecular geometrical considerations. A thermodynamic model was developed by considering the packing constraints of extractant molecules in the film forming extractant reverse micelles present in oil. It enabled the prediction of water solubility in the reverse micelles as well as the size of the micelles obtained experimentally. (authors)

  12. The Krafft temperature of surfactant solutions

    Directory of Open Access Journals (Sweden)

    Manojlović Jelena Ž.

    2012-01-01

    Full Text Available Our main motivation to revisit the solution properties of cetyltrimethylammonium bromide is related to the clear requirement for better control of the adsorption parameters to form uniform self-assembled monolayers on muscovite mica substrates. To readily monitor the temporal evolution of structural details in cetyltrimethylammonium bromide solutions, we realized a rather simple conductivity experiment. Conductivity measurements were carried out as a function of temperature, to look closer into the Krafft temperature behavior of this surfactant. We measured the electrical conductivity of different concentrations of aqueous cetyltrimethylammonium bromide solutions, below and above the critical micells concentration.

  13. Size separation of analytes using monomeric surfactants

    Science.gov (United States)

    Yeung, Edward S.; Wei, Wei

    2005-04-12

    A sieving medium for use in the separation of analytes in a sample containing at least one such analyte comprises a monomeric non-ionic surfactant of the of the general formula, B-A, wherein A is a hydrophilic moiety and B is a hydrophobic moiety, present in a solvent at a concentration forming a self-assembled micelle configuration under selected conditions and having an aggregation number providing an equivalent weight capable of effecting the size separation of the sample solution so as to resolve a target analyte(s) in a solution containing the same, the size separation taking place in a chromatography or electrophoresis separation system.

  14. Surfactant-cobalt(III) complexes: The impact of hydrophobicity on interaction with HSA and DNA - insights from experimental and theoretical approach.

    Science.gov (United States)

    Veeralakshmi, Selvakumar; Sabapathi, Gopal; Nehru, Selvan; Venuvanalingam, Ponnambalam; Arunachalam, Sankaralingam

    2017-05-01

    To develop surfactant-based metallodrugs, it is very important to know about their hydrophobicity, micelle forming capacity, their interaction with biomacromolecules such as proteins and nucleic acids, and biological activities. Here, diethylenetriamine (dien) and tetradecylamine ligand (TA) based surfactant-cobalt(III) complexes with single chain domain, [Co(dien)(TA)Cl 2 ]ClO 4 (1) and double chain domain [Co(dien)(TA) 2 Cl](ClO 4 ) 2 (2) were chosen to study the effect of hydrophobicity on the interaction with human serum albumin and calf thymus DNA. The obtained results showed that (i) single chain surfactant-cobalt(III) complex (1) interact with HSA and DNA via electrostatic interaction and groove binding, respectively; (ii) double chain surfactant-cobalt(III) complex (2) interact with HSA and DNA via hydrophobic interaction and partial intercalation, respectively, due to the play of hydrophobicity by single and double chain domains. Further it is noted that, double chain surfactant-cobalt(III) complex interact strongly with HSA and DNA, compared single chain surfactant-cobalt(III) complex due to their more hydrophobicity nature. DFT and molecular docking studies offer insights into the mechanism and mode of binding towards the molecular target CT-DNA and HSA. Hence, the present findings will create new avenue towards the use of hydrophobic metallodrugs for various therapeutic applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A liquid CO2-compatible hydrocarbon surfactant: experiment and modelling

    NARCIS (Netherlands)

    Banerjee, S.; Kleijn, J.M.; Cohen Stuart, M.A.; Leermakers, F.A.M.

    2013-01-01

    Surfactants soluble in liquid CO2 are rare and knowledge on interfacial and self-assembly behaviour is fragmented. We found that polyoxyethylene (5) isooctylphenyl ether is interfacially active at the water–liquid CO2 interface. Water–liquid CO2 interfacial tension was measured at various surfactant

  16. Binding of alkylpyridinium chloride surfactants to sodium polystyrene sulfonate

    NARCIS (Netherlands)

    Ishiguro, M.; Koopal, L.K.

    2009-01-01

    Binding of cationic surfactants to anionic polymers is well studied. However, the surfactant binding characteristics at very low concentration near the start of binding and at high concentration, where charge compensation may Occur. are less well known. Therefore, the binding characteristics of

  17. Nonionic surfactant Brij35 effects on toluene biodegradation in a ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... behaviors of toluene in a composite bead biofilter were investigated. The toluene dissolved in the water phase was enhanced by the addition of surfactant into aqueous solution and the enhancing effect was more pronounced in the surfactant concentration less than critical micelle concentration. For the.

  18. New mechanisms for phase separation in polymer-surfactant mixtures