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surfactant peptide

Tien-Sheng Tseng, Shih-Han Wang, Ting-Wei Chang, Hung-Mu Wei, Yu-June Wang, Keng-Chang Tsai, You-Di Liao, Chinpan Chen
The emergence of antibiotic-resistant microbial strains has become a public health issue and there is an urgent need to develop new anti-infective molecules. Although natural antimicrobial peptides (AMPs) can exert bactericidal activities, they have not shown clinical efficacy. The limitations of native peptides may be overcome with rational design and synthesis. Here, we provide evidence that the bactericidal activity of a synthetic peptide, GW-Q6, against Pseudomonas aeruginosa is mediated through outer membrane protein OprI...
2016: PloS One
Smeeta Sardesai, Manoj Biniwale, Fiona Wertheimer, Arlene Garingo, Rangasamy Ramanathan
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...
October 5, 2016: Pediatric Research
Wenpin Wang, Zongxia Guo, Jing Sun, Zhibo Li
The comprehensive understanding of disassembly mechanism of amyloid fibrils requires nano-scale characterization of the mechanical properties of amyloid fibrils during the disassembly process. In this work, gemini surfactant C12 C6 C12 Br2 micelles were used as a probe to disassemble Aβ(1-40) fibrils. The microstructure evolution and nano-mechanical properties of Aβ(1-40) fibrils during the disassembly process were systematically investigated by the Peak Force Quantitative Nano-mechanical (PF-QNM) technique...
October 1, 2016: Biopolymers
Alan J Waring, Monik Gupta, Larry M Gordon, Gary Fujii, Frans J Walther
Surfactant protein B (SP-B; 79 residues) is a member of the saposin superfamily and plays a pivotal role in lung function. The N- and C-terminal regions of SP-B, cross-linked by two disulfides, were theoretically predicted to fold as charged amphipathic helices, suggesting participation in surfactant activities. Previous studies with oxidized Super Mini-B (SMB), a construct based on the N- and C-regions of SP-B (i.e., residues 1-25 and 63-78) joined with a designer turn (-PKGG-) and two disulfides, indicated that freshly prepared SMB in lipids folded as a surface active, α-helix-hairpin...
September 21, 2016: Biochimica et Biophysica Acta
Ian W Hamley, Jessica Hutchinson, Steven Kirkham, Valeria Castelletto, Amanpreet Kaur, Mehedi Reza, Janne Ruokolainen
The surfactant-like peptide (Ala)6-(Asp) (A6D) is shown to self-assemble into ultrathin (3 nm thick) nanosheets in aqueous solution above a critical aggregation concentration. A combination of circular dichroism and FTIR spectroscopy and X-ray diffraction shows that the nanosheets comprise interdigitated bilayers of the peptide with β-sheet conformation. The self-assembly can be modulated by addition of hexamethylenediamine which is expected to interact with the anionic C terminus (and C-terminal D residue) of the peptide...
October 11, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Masahide Shibata, Shuhei Koeda, Tomoyasu Noji, Keisuke Kawakami, Yuya Ido, Yuichi Amano, Naoki Umezawa, Tsunehiko Higuchi, Takehisa Dewa, Shigeru Itoh, Nobuo Kamiya, Toshihisa Mizuno
The development of additional extraction surfactants for membrane proteins is necessary for membrane protein research, since optimal combinations for the successful extraction of target membrane proteins from biological membranes that minimize protein denaturation are hard to predict. In particular, those that have a unique basal molecular framework are quite attractive and highly desired in this research field. In this study, we successfully constructed a new extraction surfactant for membrane proteins, NPDGC12KK, from the peptide-gemini-surfactant (PG-surfactant) molecular framework...
August 29, 2016: Bioconjugate Chemistry
Létitia Jean, Chiu Fan Lee, Peter Hodder, Nick Hawkins, David J Vaux
Many chronic degenerative diseases result from aggregation of misfolded polypeptides to form amyloids. Many amyloidogenic polypeptides are surfactants and their assembly can be catalysed by hydrophobic-hydrophilic interfaces (an air-water interface in-vitro or membranes in-vivo). We recently demonstrated the specificity of surface-induced amyloidogenesis but the mechanisms of amyloidogenesis and more specifically of adsorption at hydrophobic-hydrophilic interfaces remain poorly understood. Thus, it is critical to determine how amyloidogenic polypeptides behave at interfaces...
2016: Scientific Reports
J I Paredes, S Villar-Rodil
Direct liquid-phase exfoliation of layered materials by means of ultrasound, shear forces or electrochemical intercalation holds enormous promise as a convenient, cost-effective approach to the mass production of two-dimensional (2D) materials, particularly in the form of colloidal suspensions of high quality and micrometer- and submicrometer-sized flakes. Of special relevance due to environmental and practical reasons is the production of 2D materials in aqueous medium, which generally requires the use of certain additives (surfactants and other types of dispersants) to assist in the exfoliation and colloidal stabilization processes...
August 25, 2016: Nanoscale
Lorenza González-Mariscal, Yanahi Posadas-Torrentera, Jael Miranda, Perla Uc, José Mario Ortega-Olvera, Sandra Hernández
Ions and molecules move across epithelial barriers by two pathways, the transcellular and the paracellular. The former is taken by lipophilic compounds, or by ions and molecules that move across the plasma membrane through pumps, carriers or exchangers. The second route is regulated by the tight junction (TJ) that through paracellular channels, allows the transport of ions across epithelial barriers. Since, a wide variety of bioactive molecules like peptides, proteins and oligonucleotides cannot use the transcellular route, due to their hydrophilic nature, interest has arisen in devising procedures to open the TJ in a reversible manner for paracellular drug delivery...
July 20, 2016: Current Pharmaceutical Design
Ronald Domalaon, Brandon Findlay, Makanjuola Ogunsina, Gilbert Arthur, Frank Schweizer
Peptides present an attractive scaffold for the development of new anticancer lead agents due to their accessibility and ease of modification. Synthetic ultrashort cationic lipopeptides, with four amino acids or less conjugated to a fatty acid, were developed to retain the biological activity of longer peptides in a smaller molecular size. Herein, we report the activity of amphiphilic lipotripeptides, lipotripeptoids and lipotetrapeptides against breast (MDA-MB-231, JIMT-1), prostate (DU145) and pancreas (MiaPaCa2) epithelial cancer cell lines...
October 2016: Peptides
Sonia M Aguilera-Segura, Vanessa Núñez Vélez, Luke Achenie, Oscar Álvarez Solano, Rodrigo Torres, Andrés Fernando González Barrios
Recent research efforts have focused on the production of environmentally nonthreatening products, including identifying biosurfactants that can replace conventional surfactants. In order to utilize biosurfactants in different industries such as cosmetic, food or petroleum, it is necessary to understand the underpinnings behind the interactions that could take place for biosurfactants which display potential for interface activity. This work aimed to use molecular dynamics simulations to understand the interactions of rationally obtained peptide sequences from the original sequence of the OmpA gene in Escherichia coli, based on the free energy change (ΔG) during peptide insertion at the water-dodecane interface...
July 2016: Journal of Molecular Graphics & Modelling
Dennis Hanzelmann, Hwang-Soo Joo, Mirita Franz-Wachtel, Tobias Hertlein, Stefan Stevanovic, Boris Macek, Christiane Wolz, Friedrich Götz, Michael Otto, Dorothee Kretschmer, Andreas Peschel
Sepsis caused by Gram-positive bacterial pathogens is a major fatal disease but its molecular basis remains elusive. Toll-like receptor 2 (TLR2) has been implicated in the orchestration of inflammation and sepsis but its role appears to vary for different pathogen species and clones. Accordingly, Staphylococcus aureus clinical isolates differ substantially in their capacity to activate TLR2. Here we show that strong TLR2 stimulation depends on high-level production of phenol-soluble modulin (PSM) peptides in response to the global virulence activator Agr...
2016: Nature Communications
Dharana Jayawardane, Fang Pan, Jian R Lu, Xiubo Zhao
Regenerated silk fibroin (RSF) is a Food and Drug Administration-approved material and has been widely used in many biomedical and cosmetic applications. Because of the amphiphilic nature of the primary repeat amino acid sequence (e.g., AGAGAS), RSF peptides can significantly reduce the water surface tension and therefore have the potential to be used as a surface active component for many applications, particularly in the biomedical, cosmetic, pharmaceutical, and food industries. In this paper, the adsorption of RSF peptides separated into molecular fractions of 5-30, 30-300, and >300 kDa has been studied at the solid-water interface by neutron reflection and spectroscopic ellipsometry to assess its surface active behavior...
August 16, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Caiyun Liao, Fangfang Li, Shanshan Huang, Baozhan Zheng, Juan Du, Dan Xiao
It is still a challenge for clinical diagnostics to design non-toxic and selective sensors for a specific analyte in blood serum, which contains a large number of proteins, small molecules, and ions. Herein, H1, a synthetic hybrid of green fluorescent protein (GFP) chromophore and peptide for human serum albumin (HSA) detection via obvious fluorescence enhancement was reported. The fluorescence response was caused by the non-covalent binding between H1 and the subdomain IIA cavity of HSA, and this specific binding behavior can be confirmed by the decrease of fluorescence intensity of the sole tryptophan residue (Trp-214) located in the same subdomain...
December 15, 2016: Biosensors & Bioelectronics
Sébastien Gélis-Jeanvoine, Alexis Canette, Michel Gohar, Thibault Caradec, Christelle Lemy, Myriam Gominet, Philippe Jacques, Didier Lereclus, Leyla Slamti
Bacteria of the Bacillus genus are able to synthesize several families of lipopeptides. These small molecules are the product of non-ribosomal peptide synthetases. In 2000, it was found that Bacillus thuringiensis, an entomopathogenic bacterium of the Bacillus cereus group, produced a previously unknown lipopeptide: kurstakin. Genomic analyses reveal that the krs locus, encoding the kurstakin synthetases, is specific to the B. cereus group, but is unevenly distributed within this group. Previous work showed that krs transcription requires the necrotrophism quorum-sensor NprR...
June 25, 2016: Research in Microbiology
Jiayuan Sheng, Joseph Stevens, Xueyang Feng
Fatty alcohols are value-added chemicals and important components of a variety of industries, which have a >3 billion-dollar global market annually. Long chain fatty alcohols (>C12) are mainly used in surfactants, lubricants, detergents, pharmaceuticals and cosmetics while medium chain fatty alcohols (C6-C12) could be used as diesel-like biofuels. Microbial production of fatty alcohols from renewable feedstock stands as a promising strategy to enable sustainable supply of fatty alcohols. In this study, we report, for the first time, that medium chain fatty alcohols could be produced in yeast via targeted expression of a fatty acyl-CoA reductase (TaFAR) in the peroxisome of Saccharomyces cerevisiae...
2016: Scientific Reports
Yue Xiao, Qiongsi Zhang, Yiquan Luo, Ying Zhang, Xi Luo, Yuchuan Wang, Weiguo Cao, Vito De Pinto, Qiuyun Liu, Gang Li
Cellulases that endure extreme conditions are essential in various industrial sectors. This study reports a mini-cellulase gene tox-1 from Neurospora crassa. The gene tox-1 was cloned in Escherichia coli after chimerization with the YebF gene and substitutions of certain isoleucine and valine with leucine residues. The yeast transformants could grow on rice straw-agar medium. The 44-amino acid peptide and its two mutant variants displayed potent cellulase activities in Congo Red assay and enzymatic assays. Conservative replacements with leucine have substantially increased the stabilities and half-lives of the peptides at alkaline pH and low and high temperatures and also the tolerance to organic solvents and surfactants, on the basis of activities toward cellose...
June 15, 2016: Journal of Agricultural and Food Chemistry
Toru Suzuki, Alexander Lyon, Rajeev Saggar, Liam M Heaney, Kenichi Aizawa, Antonio Cittadini, Ciro Mauro, Rodolfo Citro, Giuseppe Limongelli, Francesco Ferrara, Olga Vriz, Andrew Morley-Smith, Paolo Calabrò, Eduardo Bossone
Acute cardiothoracic and respiratory diseases frequently remain a challenge to diagnose and differentiate in the emergency setting. The main diseases that manifest with chest pain include ischaemic heart disease, myocarditis, acute pericarditis, aortic dissection/rupture and pulmonary embolism (PE). Diseases that primarily present with dyspnoea include heart failure (HF), acute respiratory distress syndrome (ARDS), pneumonia, asthma exacerbations and chronic obstructive pulmonary disease. Pre-test probabilities of clinical findings play a vital part in diagnostic decisions, and the use of a Bayesian approach to these greatly improves the ability to stratify patients more accurately...
September 2016: European Heart Journal. Acute Cardiovascular Care
Sudipta Bag, Susmitnarayan Chaudhury, Dibyendu Pramanik, Sunando DasGupta, Swagata Dasgupta
The amyloid β-peptide fragment comprising residues 25-35 (Aβ25-35 ) is known to be the most toxic fragment of the full length Aβ peptide which undergoes fibrillation very rapidly. In the present work, we have investigated the effects of the micellar environment (cationic, anionic, and nonionic) on preformed Aβ25-35 fibrils. The amyloid fibrils have been prepared and characterized by several biophysical and microscopic techniques. Effects of cationic dodecyl trimethyl ammonium bromide (DTAB), cetyl trimethylammonium bromide (CTAB), anionic sodium dodecyl sulfate (SDS), and nonionic polyoxyethyleneoctyl phenyl ether (Triton X-100 or TX) on fibrils have been studied by Thioflavin T fluorescence, UV-vis spectroscopy based turbidity assay and microscopic analyses...
September 2016: Proteins
Mays A Al-Dulaymi, Jackson M Chitanda, Waleed Mohammed-Saeid, Hessamaddin Younesi Araghi, Ronald E Verrall, Pawel Grochulski, Ildiko Badea
The aim of this work was to elucidate the structure-activity relationship of new peptide-modified gemini surfactant-based carriers. Glycyl-lysine modified gemini surfactants that differ in the length and degree of unsaturation of their alkyl tail were used to engineer DNA nano-assemblies. To probe the optimal nitrogen to phosphate (N/P) ratio in the presence of helper lipid, in vitro gene expression and cell toxicity measurements were carried out. Characterization of the nano-assemblies was accomplished by measuring the particle size and surface charge...
September 2016: AAPS Journal
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