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surfactant peptide

Kuan-Hung Lin, Shu-Ting Hong, Hsiang-Tsui Wang, Yu-Li Lo, Anya Maan-Yuh Lin, James Chih-Hsin Yang
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI), such as gefitinib, have been demonstrated to effectively treat the patients of extracranial non-small cell lung cancer (NSCLC). However, these patients often develop brain metastasis (BM) during their disease course. The major obstacle to treat BM is the limited penetration of anticancer drugs across the blood-brain barrier (BBB). In the present study, we utilized gefitinib-loaded liposomes with different modifications to improve gefitinib delivery across the in vitro BBB model of bEnd...
November 29, 2016: International Journal of Molecular Sciences
Prabhu Dhasaiyan, Bhagavatula L V Prasad
The current buzzword in science and technology is self-assembly and molecular self-assembly is one of the most prominent fields as far as research in chemical and biological sciences is concerned. Generally, self-assembly of molecules occurs through weak non-covalent interactions like hydrogen bonding, π-π stacking, hydrophobic effects, etc. Inspired by many natural systems consisting of self-assembled structures, scientists have been trying to understand their formation and mimic such processes in the laboratory to create functional "smart" materials, which respond to temperature, light, pH, electromagnetic field, mechanical stress, and/or chemical stimuli...
November 25, 2016: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
Joshua Ravensdale, Zachary Wong, Frances O'Brien, Keith Gregg
Clinical application of antimicrobial peptides (AMPs), as with conventional antibiotics, may be compromised by the development of bacterial resistance. This study investigated AMP resistance in methicillin resistant Staphylococcus aureus, including aspects related to the resilience of the resistant bacteria toward the peptides, the stability of resistance when selection pressures are removed, and whether resistance can be overcome by using the peptides with other membrane-permeabilising agents. Genotypically variant strains of S...
2016: Frontiers in Microbiology
Qianqian Chen, Bo Liu, Jieping Wang, Jianmei Che, Guohong Liu, Xiong Guan
This study aimed to develop biocontrol Bacillus and explore bacterial biocontrol substances. According to the blood agar test, strain FJAT-14262 was screened as a biosurfactant-producer. The biosurfactant-producing ability of FJAT-14262 was further confirmed by the oil spreading tests because of its amphipathic character. Furthermore, its fermentation supernatant could decrease the surface tension from 74.1 to 32.7 mN m(-1). Fourier transform infrared spectroscopy (FT-IR) analysis indicated that the biosurfactant produced by the strain FJAT-14262 was a kind of lipopeptides...
November 16, 2016: Applied Biochemistry and Biotechnology
Koji Kinoshita, Elisa Parra, David Needham
Currently available dynamic surface tension (DST) measurement methods, such as Wilhelmy plate, droplet- or bubble-based methods, still have various experimental limitations such as the large size of the interface, convection in the solution, or a certain "dead time" at initial measurement. These limitations create inconsistencies for the kinetic analysis of surfactant adsorption/desorption, especially significant for ionic surfactants. Here, the "micropipette interfacial area-expansion method" was introduced and validated as a new DST measurement having a high enough sensitivity to detect diffusion controlled molecular adsorption at the air-water interfaces...
February 15, 2017: Journal of Colloid and Interface Science
Robert H Notter, Rohun Gupta, Adrian L Schwan, Zhengdong Wang, Mohanad Gh Shkoor, Frans J Walther
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)...
2016: PeerJ
Mao-Wei Ni, Lu Wang, Wei Chen, Han-Zhou Mou, Jie Zhou, Zhi-Guo Zheng
RATIONALE: Mass spectrometry-based protein identification depends mainly on protein extraction and digestion. Although sodium dodecyl sulfate (SDS) can preclude enzymatic digestion and interfere with mass spectrometry analysis, it is still the most widely used surfactant in these steps. To overcome these disadvantages, a SDS-compatible proteomic technique for SDS removal prior to mass-spectrometry-based analyses was developed, namely filter-aided sample preparation (FASP). METHODS: Herein, based on the effectiveness of sodium deoxycholate and detergent removal spin column, we developed a modified FASP (mFASP) method and compared its overall performance, total number of peptides and proteins identified for shotgun proteomic experiments with that of FASP method...
October 29, 2016: Rapid Communications in Mass Spectrometry: RCM
Ronivaldo Rodrigues da Silva, Lilian Caroline Gonçalves de Oliveira, Maria Aparecida Juliano, Luiz Juliano, Jose C Rosa, Hamilton Cabral
Peptidases are enzymes that catalyze the rupture of peptide bonds. Catalytic specificity studies of these enzymes have illuminated their modes of action and preferred hydrolysis targets. We describe the biochemical characteristics and catalytic specificity of a lysine-dependent peptidase secreted by the basidiomycete fungus Phanerochaete chrysosporium. We attained 5.7-fold purification of a ∼23-kDa neutral peptidase using size-exclusion (Sephadex G-50 resin) and ion-exchange (Source 15S resin) chromatography...
October 19, 2016: International Journal of Biological Macromolecules
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...
December 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...
August 18, 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, Jael Miranda, Perla Yaceli 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...
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...
July 29, 2016: Nature Communications
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