Small ~8.5 nm discs formed spontaneously when and dimyristoyl phosphatidylcholine (DMPC) large unilamellar vesicles (LUVs) were incubated with apolipoprotein A-I (apoA-I) (100:1 molar ratio). However, in a time course study, the transient production of ~11 nm large discs was detected and isolated by gel filtration. ...

We have synthesized a model lipid-associating peptide of 20 residues (LAP-20) and studied its association with the phospholipid dimyristoyl phosphatidylcholine (DMPC) and its activation of the plasma enzyme lecithin:cholesterol acyl-transferase (EC 2.3.1.43). The lipid-associating behavior of LAP-20 is similar to that of well-characterized native plasma apolipoproteins after ...

Incubation of a major subfraction, HDL/sub 2b/(d 1.063-1.100 g/ml), with single-bilayer liposomes of dimyristoylphosphatidylcholine (DMPC) resulted in uptake of DMPC by the HDL/sub 2b/ and dissociation of lipid-free apolipoprotein A-I (apoA-I). In the presence of excess DMPC, the dissociated ...

Differential scanning calorimetry, Fourier transformed infrared (FTIR) spectroscopy and small angle scattering of synchrotron radiation have been used to analyse the influence of zwitterionic surfactant (3-(N-hexylmorpholine)-1-propansulfonate) on the conformational dynamics of CH2 and CH3 groups of 1,2-dimyrilstoyl-sn-glycero-3-phosphocholine (DMPC) and ...

Fourier transformed infrared (FTIR) spectroscopy and small-angle scattering of synchrotron radiation have been used to analyze the influence of two zwitterionic surfactants of the sulfobetaine structure (3-(N-decylmorpholine)-1-propansulfonate and 3-(N-tetradecylmorpholine)-1-propansulfonate) on the conformational dynamics of CH2 and O-P-O groups of ...

Apolipoprotein A-I-Milano(AIM), a natural variant, not only inhibits the initiation and progression of atherosclerosis, but also makes the preexisting atherosclerotic lesions regress. AIM gene, at which N-terminal codens were optimized, was subcloned into the expression vector of pET22b. Recombiant plasmids were transformed into E. coli strain BL21 (DE3) and induced with IPTG. ...

The delivery of genes or viruses via liposomes is a common approach used to enhance delivery efficiency. In the current study, to enhance delivery efficiency, proteoliposomes (PLs) containing adenovirus (Ad) were synthesized with dimyristoylphosphatidylcholine (DMPC), cholesterol, and apolipoprotein A-I (apoA-I). Wildtype ...

phospholipid vesicles (SUV and LUV) as model membranes. Af shows a high membrane affinity with a partition with DMPC SUV. These properties are due to the phospholipid-like conformation of Af and the more extended of Vesicles. Unilamellar vesicles were pre- pared by either sonication for small unilamellar vesicles (SUV

Because of its role in reverse cholesterol transport, human apolipoprotein A-I is the most widely studied exchangeable apolipoprotein. Residues 1-43 of human apoA-I, encoded by exon 3 of the gene, are highly conserved and less well understood than residues 44-243, encoded by exon 4. In contrast to residues 44-243, residues 1-43 do not contain the 22 amino ...

Charge density measurements and polarization modulation infrared reflection absorption spectroscopy were employed to investigate the spreading of small unilamellar vesicles of a dimyristoylphosphatidylcholine (DMPC)/cholesterol (7:3 molar ratio) mixture onto an Au (111) electrode surface. The electrochemical experiments demonstrated that vesicles fuse and ...

We examined how electrostatic shielding affects the formation of two-dimensional (2D) crystals of bacteriorhodopsin (bR) in reconstituted dimyristoylphosphatidylcholine (DMPC) membranes by varying the sodium chloride (NaCl) concentration. The 2D crystalline array of bR formed in the gel phase of DMPC membranes was characterized by a symmetric bipolar ...

We have studied how local anesthetics influence the structural and dynamical properties of model bio-membranes. The measurements of small-angle neutron scattering have been performed on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) unilamellar vesicles with different concentrations of lidocaine in D2O to determine the bilayer thickness as a function ...

To address the question of how local anesthetics influences the structural and dynamical properties of bio-membranes, neutron-spin echo spectroscopy (NSE) has been performed on 1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine (DMPC) unilamellar vesicles (ULV) with different concentrations of Lidocaine in D2O to study the influence of Lidocaine on the bending elasticity of ...

An image-based technique of fluorescence recovery after photobleaching (video-FRAP) was used to measure the lateral diffusion coefficients of a series of nine fluorescent probes in two model lipid bilayer systems, dimyristoylphosphatidylcholine (DMPC) and DMPC/cholesterol (40 mol%), as well as in human stratum corneum-extracted lipids. The probes were all ...

The report, part of major A.I.D. stock-taking of its experience with microenterprises, describes the composition and growth potential of Malawi's small enterprise sector, followed by an evaluation of the institutions - the Development of Malawi Traders Tr...

We report on the formation of bicelles from a mixture of dimyristoylphosphatidylcholine (DMPC) and the chelator-lipid dimyristoylphosphatidylethanolamine-diethylenetriaminepentaacetate (DMPE-DTPA) with complexed lanthanides, either thulium (Tm(3+)) or lanthanum (La(3+)). The two phospholipids used have the same acyl-chain length but differ in headgroup size and chemical ...

We studied the influence of 5 kDa poly(acrylic acid) (PAA) on the phase state, thermal properties, and lateral diffusion in bilayered systems of dimyristoylphosphatidylcholine (DMPC) using (31)P NMR spectroscopy, differential scanning calorimetry (DSC), (1)H NMR with a pulsed field gradient, and (1)H nuclear Overhauser enhancement spectroscopy (NOESY). The presence of PAA does ...

Ultrathin titanium layers when deposited on the surface of gold can be successfully applied for infrared reflection absorption spectroscopy (IRRAS) investigations. It was shown that the reflectivity, the phase shift, and the mean square electric field of the p- and s-polarized IR radiation in up to 20 nm thick titanium layers covered with a 3-4 nm thick layer of native oxide are comparable to ...

Nanometer scale apolipoprotein A-I stabilized phospholipid disk complexes (nanodisks; ND) have been formulated with the polyene antibiotic amphotericin B (AMB). The present studies were designed to evaluate if a peptide can substitute for the function of the apolipoprotein component of ND with respect to particle formation and stability. An 18-residue synthetic amphipathic ...

The stabilizing or disturbing effect of different surfactants on the bicellar phase of phospholipids significantly depends on their type. The effect of different surfactants on the bicellar structure made of a mixture of phospholipids 1,2-dimyristoyl-sn-glycero-3-phosphocholine and 1,2-dihexanoyl-sn-glycero-3-phospho-choline (DMPC/DHPC) has been studied by the ...

X-ray diffraction data taken at high instrumental resolution were obtained for EPC and DMPC under various osmotic pressures, primarily at T = 30�C. The headgroup thickness D_HH was obtained from relative electron density profiles. By using volumetric results and by comparing to gel phase DPPC we obtain areas AEPCF=69.4�1.1?2 and ADMPCF=59.7�0.2?2. ...

A study of the fractal dimension of the aggregation of three different types of large unilamellar vesicles, formed by egg yolk phosphatidylcholine (EYPC), dimyristoyl-phosphocholine (DMPC), and dipalmitoyl-phosphocholine (DPPC), in the presence of La3+ , is presented. Aggregate liposome fractal dimensions were calculated by two methods, aggregation kinetics, using the ...

The sequences of the plasma apolipoproteins have a high degree of internal homology as they contain several 22-mer internal repeats. These amphipathic helical repeats are considered as the structural and functional units of this class of proteins. We proposed that the 22-mer repeats of the plasma apolipoproteins consist of 17-mer helical segments separated by extended beta-strands comprising five ...

Investigation of the deuterium (2H) nuclear magnetic resonance (NMR) relaxation rates of lipid bilayers containing cholesterol can yield new insights regarding its role in membrane function and dynamics. Spin-lattice (R1Z) and quadrupolar order (R1Q) 2H NMR relaxation rates were measured at 46.1 and 76.8 MHz for macroscopically oriented bilayers of ...

Apolipoprotein A-I (apoA-I), the major protein component of plasma high-density lipoprotein (HDL), exists in alternate lipid-free and lipid-bound states. Among various species, chicken apoA-I possesses unique structural properties: it is a monomer in the lipid-free state and it is virtually the sole protein component of HDL. Near-UV ...

The contribution of the upper atmosphere to small effects in the hard component of cosmic rays during chromospheric flares. Author: Kuzmin, A. I. ...

... tendency to align along the IV- curve in the quasistatic / limit for small D. / A. I- V curves , The averaged velocity vo = I f vdt over a basic period .... ...

Using molecular dynamics (MD) simulations, we studied the structure and dynamics of two dimyristoylphosphatidylcholine (DMPC):cholesterol bilayers at concentrations representative of the ocular lens (ratios of 1:1 and 1:2). These MD simulations agree well with experimental deuterium order parameters and bilayer peak-to-peak distances. Although it is known that the average ...

Mixed vesicles of dimyristoylphosphatidylcholine (DMPC) and a polymerizable lipid containing one diene group per chain are studied by freeze fracture electron microscopy and by the photobleaching (fluorescence recovery after photobleaching) technique. Large thin-walled vesicles of some micron in diameter become more stable after photochemical polymerization. Before ...

We report the modification of the bending elastic modulus k_c of lipid bilayers (here DMPC) by small amounts (c leq 5 mol %) of (i) small amphiphiles which exchange between the bilayer and the aqueous phase (e.g. the ion carrier valinomycin and the Ca^{++} carrier A23187) and (ii) amphiphiles solubilized in the membrane (cholanic ...

Fourier transform infrared (FTIR) attenuated total reflection (ATR) spectroscopy was used to elucidate the hydration behavior and molecular order of phospholipid/ganglioside bilayers. We examined dry and hydrated films of the gangliosides GM1, deacetyl-GM1, lyso-GM1, deacetyllyso-GM1, and GM3 and oriented mixed films of these gangliosides with 1,2-dimyristoyl-sn-glycero-3-phosphorylcholine ...

Contents: 'Small Farmer Agricultural Credit in Ivory Coast' by The Staff of the National Bank for Agricultural Development; 'National Center for Promotion of Cooperative Enterprises in Ivory Coast' by Samuel Nnebe; 'Institutional Credit for Smallholder Fa...

Nanometric bilayer-based self-assembled micelles commonly named as bicelles, formed with a mixture of long and short chains phosphatidylcholine lipids (PC), are known to orient spontaneously in a magnetic field. This field-induced orientational order strongly depends on the molecular structure of the phospholipids. Using small-angle X-ray scattering (SAXS), we performed ...

The ripple structure was studied as a function of temperature in fully hydrated dimyristoylphosphatidylcholine (DMPC)/cholesterol multibilayers using synchrotron x-ray small-angle diffraction and freeze-fracture electron microscopy. In the presence of cholesterol, the ripple structure appears below the pretransition temperature of pure ...

The major protein of bovine seminal plasma, PDC-109 binds to choline phospholipids present on the sperm plasma membrane upon ejaculation and plays a crucial role in the subsequent events leading to fertilization. PDC-109 also shares significant similarities with small heat shock proteins and exhibits chaperone-like activity (CLA). Although the polydisperse nature of this ...

The contribution of ABCA1-mediated efflux of cellular phospholipid (PL) and cholesterol to human apolipoprotein A-I (apoA-I) to the formation of pre?1-HDL (or lipid-poor apoA-I) is not well defined. To explore this issue, we characterized the nascent HDL particles formed when lipid-free apoA-I was incubated with ...

ObjectiveTo investigate the interaction of SAA and SR-BI in remodeling of acute phase HDL (AP HDL).Methods and ResultsWe used SAA and SR-BI adenoviral vector expression models to study the interaction between these entities. SR-BI processing of mouse AP HDL generated progressively smaller discreet HDL particles with distinct apolipoprotein compositions. SR-BI actions segregated apolipoproteins ...

Cholesterol Orientation and Tilt Modulus in DMPC Bilayers George Khelashvili,*, Georg Pabst- toylphosphatidylcholine (DMPC) and cholesterol at various ratios, to study the effect of cholesterol concentration on its orientation, and to characterize the link between cholesterol tilt and overall phospholipid membrane

This volume consists of four separate reports describing the program characteristics, evaluation and role of technical assistance regarding farm credit as it is institutionalized and practiced in Pakistan. The titles and authors of these reports are as fo...

This volume consists of three separate reports describing the program characteristics, evaluation and role of technical assistance regarding farm credit as it is institutionalized and practiced in Thailand. The titles and authors of these reports are as f...

The volume consists of five separate reports describing the program characteristics, evaluation and role of technical assistance of farm credit as it is institutionalized and practiced in various countries in West Asia. The titles and authors of these rep...

The volume consists of four separate reports describing the program characteristics, evaluation and role of technical assistance regarding farm credit as it is institutionalized and practiced in Ecuador. The titles and authors of these reports are as foll...

The volume consists of four separate reports describing the program characteristics, evaluation and role of technical assistance regarding farm credit as it is institutionalized and practiced in four countries in South America. The titles and authors of t...

Using neutron diffraction and a specially constructed high pressure cell suitable for aligned multibilayer systems, we have studied, as a function of pressure, the much observed anomalous swelling regime in dimyristoyl- and dilauroyl-phosphatidylcholine bilayers, DMPC and DLPC, respectively. We have also reanalyzed data from a number of previously published experiments and ...

In atherosclerotic artery walls, mast cells, an inflammatory cell, are activated and secrete some proteases including chymase. Chymase, a chymotrypsin-like protease, cleaves the C-terminus of apolipoprotein A-I (apoA-I) at Phe225. This cleavage reduces the ability of apoA-I to promote the efflux of cellular cholesterol. The aim of this study is to detect ...

PHOTW3A PHXC RECORHIIFG,OF SMALL MOTIONS. By. F. H. ~OrtO~,. ~fficist,. AerodyninriioulLdmratory, N. A, C. A.I- k@ey. Field,Va. November,1920. ...

Citation, Bus, S., Binzel, R. P. Small Main-belt Asteroid Spectroscopic Survey, Phase II. EAR-A-I0028-4-SBN0001/SMASSII-V1.0. NASA Planetary Data System, ...

Hematoporphyrin is being used as a photosensitizer in photodynamic therapy of tumors, as well as of other clinical cases. Many classes of tetrapyrroles, including hematoporphyrin, are partitioning quite easily into the external cytoplasmic membrane as the mechanism of cellular uptake. Several chemical and physical parameters of the membrane were studied for their effect on the extent of ...

Phospholipid bicelles were employed as a membrane bilayer model in the conformational studies of two lipophilic cannabinoids, delta(8)-THC and its O-methyl ether analogue, Me-Delta(8)-THC using conventional high-resolution NMR. A preparation of 8% (w/v) phospholipid concentration and a high DMPC/DHPC ratio (q = 2.0) was found to be optimal for not only effectively ...

This article describes efforts to build a model biological membrane at a surface of a gold electrode. In this architecture, the membrane may be exposed to static electric fields on the order of 10(7) to 10(8) V m(-1). These fields are comparable in magnitude to the static electric field acting on a natural biological membrane. The field may be conveniently used to manipulate organic molecules ...

Stopped-flow fluorometry has been employed to study the effects of melittin, the major protein component of bee venom, on dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC) small unilamellar vesicles (SUVs) on the millisecond time scale, before melittin-induced vesicle fusion takes place. Use is made of ...

The relationship between molecular architecture and the nature of interactions with lipid bilayers has been studied for a series of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers using small-angle X-ray scattering (SAXS) and thermal analysis (differential scanning calorimetry, DSC). The number of molecular repeat units in ...

Two-dimensional electrophoretic analysis of plasma lipoproteins from male Osborne-Mendel rats consistently reveals three isoforms of apolipoprotein A-I (apo-A-I) with the following apparent pI values and quantitative distribution: isoform 3, pI = 5.68, 69%; isoform 4, pI = 5.55, 29%; isoform 5, pI = 5.44, 2%. The two major isoforms were obtained by ...

Bicellar model membranes composed of 1,2-dimyristoylphosphatidylcholine (DMPC) and 1,2-dihexanoylphosphatidylcholine (DHPC), with a DMPC/DHPC molar ratio of 5, and doped with the negatively charged lipid 1,2-dimyristoylphosphatidylglycerol (DMPG), at DMPG/DMPC molar ratios of 0.02 or 0.1, were examined using small ...

The lateral distribution of 1-palmitoyl-2-(10-(1-pyrenyl)decanoyl)phosphatidylcholine (PyrPC) was studied in small unilamellar vesicles of 1,2-dipalmitoyl-, 1,2-dimyristoyl-, and 1-palmitoyl-2-oleoyl-phosphatidylcholine (DPPC, DMPC, and POPC, respectively) under anaerobic conditions. The DPPC and DMPC experiments were carried out over ...

Three structurally related crown compounds and cryptands have been synthesized that differ by the number and linkage of coronand units and anthracene moieties. The interaction of the fluorescent dyes with sonicated dimyristoylphosphatidylcholine (DMPC) vesicles is characterized by the relative quantum yields, uptake kinetics, binding curves, lifetimes, fluorescence titrations ...

The report explores the constraints and opportunities facing the development of the private sector in Uzbekistan and presents a strategy for the Agency for International Development (A.I.D.) response. Part 1 examines the national context for small enterpr...

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Can labor-intensive (pick and shovel) construction of market access roads in the mountainous regions of Colombia result in significant improvements in the welfare of local campesinos. This document assesses the impact of one such effort--The A.I.D.'s Smal...

The purpose of this review is to highlight recent advances toward the refinement of a three-dimensional structure for lipid-bound apolipoprotein A-I (apoA-I) on recombinant HDL. Recently, X-ray crystallography has yielded a new structure for full-length, lipid-free apoA-I. Although this approach has not yet been successful in solving ...

The purpose of this review is to highlight recent advances toward the refinement of a three-dimensional structure for lipid-bound apolipoprotein A-I (apoA-I) on recombinant HDL. Recently, X-ray crystallography has yielded a new structure for full-length, lipid-free apoA-I. Although this approach has not yet been successful in solving ...

The major apoprotein of high density lipoprotein is apolipoprotein A-I (ApoA-I). In addition to being a structural component of this class of lipoproteins, ApoA-I also has a physiologic role as an activator of lecithin-cholesterol acyl transferase, an enzyme important in the metabolism of all lipoproteins.To measure ...

In a previous study, we observed a series of dips in the plot of E/M (the ratio of excimer to monomer fluorescence intensity) versus the mole fraction of 1-palmitoyl-2-(10-pyrenyl)decanoyl-sn-glycerol-3-phosphatidylcholine (Pyr-PC) in Pyr-PC/DMPC binary mixtures at 30 degrees C. In the present study, we have characterized the physical nature of E/M dips in ...

The first step in reverse cholesterol transport is the movement of cholesterol out of cells onto lipoprotein acceptors in the interstitial fluid. The contribution of specific lipoprotein components to this process remains to be established. In this study, the role of human apolipoproteins (apo) A-I and A-II in the efflux of cellular cholesterol was investigated in transgenic ...

SummaryRecent models of lipid-free apolipoprotein A-I, including a cross-link/homology model and an x-ray crystal structure have identified two potential functionally relevant �patches� on the protein surface. The first is a hydrophobic surface patch composed of leucine residues 42, 44, 46, and 47 and the second a negatively charged patch composed of glutamic acid residues ...

The volume brings together a number of studies used in the Spring Review. The Whitaker paper presents tentative results from an ongoing AID/GOC quantitative evaluation of the INCORA small farmer credit program in Colombia. The Ribeiro/Wharton and Tendler ...

'The Agricultural Credit Project of the Agricultural Sector Program of Costa Rica' by Albert L. Brown describes a search for changes in credit policy and practice which will assure availability of credit to small farmers. A joint fund provides money which...

We investigated the thermotropic behavior of fully hydrated saturated cationic lipid mixture of DMPC/DMTAP (dimyristoylphosphatidyl-choline/dimyristoyl-trimethyl-am monium propane) complexed with DNA. Using simultaneous small- and wide-angle X-ray scattering, we found two condensed lamellar phases, a fluid Lc?- and a gel-state Lc?'-phase. The chain-melting ...

Antimicrobial peptides (AMPs) are a class of small (less than100 residues) host defense peptides that induce selective membrane lytic activity against microbes. To understand the mechanism of membrane disruption by AMPs, we investigated, via atomic force microscopy, topological changes in supported phospholipid bilayers induced by protegrin-1 (PG-1). We have observed that PG-1 ...

Structural phase diagram of a phospholipid mixture composed of dimyristoyl phosphatidylcholine (DMPC), dihexanoyl phosphatidylcholine (DHPC) and dimyristoyl phosphatidylglycerol (DMPG) contains many rich morphologies, e.g., nanodiscs also known as "bicelles", bilayered ribbons, unilamellar vesicles (ULVs), multi-lamellar vesicles (MLVs) and perforated lamellae. In this report, ...

The partitioning of apolipoprotein A-I (apoA-I) molecules in plasma between HDL-bound and -unbound states is an integral part of HDL metabolism. We used the surface plasmon resonance (SPR) technique to monitor in real time the reversible binding of apoA-I to HDL. Biotinylated human HDL(2) and HDL(3) were immobilized on a streptavidin-coated SPR sensor ...

The partitioning of apolipoprotein A-I (apoA-I) molecules in plasma between HDL-bound and -unbound states is an integral part of HDL metabolism. We used the surface plasmon resonance (SPR) technique to monitor in real time the reversible binding of apoA-I to HDL. Biotinylated human HDL₂ and HDL₃ were ...

Kinetic turnover studies of apolipoprotein metabolism often utilize radioiodinated tracers. These studies rely on the tracer assumption that the modified tracer is physiologically and metabolically identical with the native unmodified tracer. This paper addresses the validity of this assumption on the basis of the examination of the state of self-association and binding properties with egg yolk ...

SUMMARYHigh-density lipoproteins (HDL) are complexes of proteins (mainly apoA-I and apoA-II) and lipids that remove cholesterol and prevent atherosclerosis. Understanding distinct properties of the heterogeneous HDL population may help develop new diagnostic tools and therapies for atherosclerosis. Mature human HDL form two major subclasses differing in particle diameter and ...

Whereas hepatocytes secrete the major human plasma high density lipoproteins (HDL)-protein, apo A-I, as lipid-free and lipidated species, the biogenic itineraries of apo A-II and apo E are unknown. Human plasma and HepG2 cell-derived apo A-II and apo E occur as monomers, homodimers and heterodimers. Dimerization of apo A-II, which is more lipophilic than apo ...

The tertiary structure of apolipoprotein (apo) A-I and the contributions of structural domains to the properties of the protein molecule are not well defined. We used a series of engineered human and mouse apoA-I molecules in a range of physical-biochemical measurements to address this issue. Circular dichroism measurements of alpha-helix thermal unfolding ...

The lipophilic dye merocyanine 540 (MC540) was used to model small molecule-membrane interactions using micropatterned lipid bilayer arrays (MLBAs) prepared using a 3D Continuous Flow Microspotter (CFM). Fluorescence microscopy was used to monitor MC540 binding to fifteen different bilayer compositions simultaneously. MC540 fluorescence was two times greater for bilayers ...

Shape transformations of vesicles of dimyristoylphosphatidylcholine (= DMPC) and palmitoyloleylphosphatidylcholine (= POPC) in ion-free water were induced by changing the area-to-volume ratio via temperature variations. Depending on the pretreatment we find several types of shape changes for DMPC (in pure water) at increasing area-to-volume ratio: (a) ...

Membrane fusion is an important event in many biological processes and is characterized by several intermediate steps of which content mixing between the two fusing vesicles signals the completion of the process. Fusion induced solely by small drug molecules is not a common event. Non Steroidal Anti-Inflammatory Drugs (NSAIDs), that control pain and inflammation, are also ...

A lipid bilayer deposited on an electrode surface can serve as a benchmark system to investigate lipid-protein interactions in the presence of physiological electric fields. Recoverin and myelin-associated glycoprotein (MAG) are used to study the impact of strong and weak protein-lipid interactions on the structure of model lipid bilayers, respectively. The structural changes in lipid bilayers are ...

Aqueous phospholipid mixtures that form bilayered micelles (bicelles) have gained wide use by molecular biophysicists during the past 20 years for spectroscopic studies of membrane-bound peptides and structural refinement of soluble protein structures. Nonetheless, the utility of bicelle systems may be compromised by considerations of cost, chemical stability, and preservation of the bicelle ...

We present results of molecular dynamics simulations of fully hydrated DMPC bilayers performed on graphics processing units (GPUs) using current state-of-the-art non-polarizable force fields and a local GPU-enabled molecular dynamics code named FEN ZI. We treat the conditionally convergent electrostatic interaction energy exactly using the particle mesh Ewald method (PME) for ...

Ultrasonic relaxation measurement was employed for confirmation of the interaction between dimyristoylphosphatidylcholine (DMPC) membrane and a soluble protein, carbonic anhydrase II (CA II). The enhancement of the fluctuation of DMPC membrane structure was observed in the presence of CA II under acidic condition, pH 3.6-4, indicating the interaction ...

Characterization of the transport and release of phospholipids from a silicone hydrogel contact lens is required to assess the possible use of these lenses for phospholipid delivery to increase patient comfort. Contact lenses of silicone hydrogel composition were loaded with varying amounts of radiolabeled 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) from a solution of ...

Anionic lipids are key components in the cell membranes. Many cell-regulatory and signaling mechanisms depend upon a complicated interplay between them and membrane-bound proteins. Phospholipid bilayers are commonly used as model systems in experimental or theoretical studies to gain insight into the structure and dynamics of biological membranes. We report here 200-ns-long MD simulations of pure ...

With molecular dynamics simulations of phospholipid membranes becoming a reality, there is a growing need for experiments that provide the molecular details necessary to test these computational results. Pyridine is used here to explore the interaction of planar aromatic groups with the water-lipid interface of membranes. It is shown by magic angle spinning 13C nuclear magnetic resonance (NMR) to ...

Equinatoxin II (EqtII) is a pore-forming protein from Actinia equina that lyses red blood cell and model membranes. Lysis is dependent on the presence of sphingomyelin (SM) and is greatest for vesicles composed of equimolar SM and phosphatidylcholine (PC). Since SM and cholesterol (Chol) interact strongly, forming domains or "rafts" in PC membranes, (31)P and (2)H solid-state NMR were used to ...

The present results report for the first time a systematic study of the effect of arbutin on the dipole potential of lipid membranes. The dipole potential and the area per lipid were measured in monolayers of dimyristoylphosphatidylcholine (DMPC), 1,2-di-O-tetradecyl-sn-glycero-3-phosphocholine (dietherPC), dimyristoylphosphatidylethanolamine (DMPE) and ...

For several decades, the standard model for high density lipoprotein (HDL) particles reconstituted from apolipoprotein A-I (apoA-I) and phospholipid (apoA-I/HDL) has been a discoidal particle ?100 ? in diameter and the thickness of a phospholipid bilayer. Recently, Wu et al. (Wu, Z., Gogonea, V., Lee, X., Wagner, M. A., Li, X. M., ...

Optical-trapping confocal Raman microscopy enhances the capabilities of traditional Raman spectroscopy for the analysis of small particles by significantly reducing the sampling volume and minimizing background signal from the particle surroundings. Chemical composition and structural information can be obtained from optically trapped particles in aqueous solution without the ...

The influence of dimethyl sulfoxide (CH3)2SO (DMSO) on the structure of membranes of 1,2-dimiristoyl- sn-glycero-3-phosphatidylcholine (DMPC) in an excess of a water-DMSO solvent is investigated over a wide range of DMSO molar concentrations 0.0 ? X DMSO ? 1.0 at temperatures T = 12.5 and 55�C. The dependences of the repeat distance d of multilamellar membranes and the ...

Lipid bilayers have long been considered simple homogeneous passive barriers. However, there is a growing consensus that bilayer composition and properties impact their role in membrane function. One molecule which participates in lipid bilayers is ethanol. Ethanol is principally known to increase membrane permeability, serving as a model drug enhancer. While bilayer permeability was thought to ...

Spontaneous cholesterol exchange between small unilamellar vesicles comprised of different phospholipids and their binary mixtures has been studied in order to understand the factors involved in the establishment and maintenance of intracellular cholesterol distributions. Exchange was performed from neutral donor vesicles containing different cholesterol concentrations, traces ...

Spontaneously forming small unilamellar vesicles (SULVs) are easy to prepare and show great promise for use in delivering therapeutic payloads. We report of SULVs made up of the ternary phospholipid mixture, dimyristoyl-phosphatidylcholine (DMPC), dihexanoyl-phosphatidylcholine (DHPC) and dimyristoyl-phosphatidylglycerol (DMPG), which have been ...

The local lipid composition near a transmembrane helical peptide in mixed-lipid bilayers has been studied using a mixed molecular dynamics (MD) and configuration-bias Monte Carlo method that allows the lateral distribution of lipids to equilibrate much more quickly than is possible by diffusive mixing alone. Gramicidin-A peptide was embedded in bilayer mixtures of DMPC with ...

The impact evaluation examines policy reform programs supported by the Agency for International Development (A.I.D.) in two small Caribbean island countries, Dominica and Grenada. Dominica now has in place a tax system that provides good economic incentiv...

Field research was conducted from 1986 to 1989 to determine the effect of traditional land tenure/allocation arrangements on agricultural performance in the Agency for International Development's (A.I.D.'s) village-level irrigated perimeters project in Ba...

PDSS...1..484B %A Bus, S.;Binzel, R. P. %H %T 2625 Jack London CCD Spectrum %X EAR-A-I0028-4-SBN0001/SMASSII-V1.0[2625JACKLO01] %D Year of acceptance into ...

A one-dimensional magnetophotonic crystal (1D-MPC) with a granular magnetic film has a large Faraday rotation angle at a localized photonic state inside a photonic forbidden band gap. The great advantage of using the granular magnetic film is that a thermal annealing process is unnecessary, which is in contrast to a 1D-MPC with a Bi:YIG film. We describe ...

�ciently small #21; > 0, d = 1 : hhw; (#21; L) 1 wii #21; C#21; 1=4 ; (1.16) d = 2 : hhw 1 ; (#21; L) 1 w 1 ii #21; C #12; #12; log hhu 2 ; wii = hhw; (#21; L n ) 1 wii. For example hhw; h #21; S +A #3; + (#21; S) 1 A+ i 1 wii =hhw; (#21; L 3 ) 1 wii: (2.14) hhw; h #21; S +A #3; + #26; #21; S +A #3; + (#21; S) 1 A+ #27; 1 ...

The rates of spontaneous interbilayer and transbilayer exchange of ({sup 3}H)dimyristoylphosphatidylcholine (({sup 3}H)DMPC) were examined in the DMPC and DMPC/dimyristoylphosphatidylethanolamine (DMPE) large unilamellar vesicles in the liquid-crystalline-, gel-, and mixed-phase states. DMPC desorption rates from ...

... investigation of how the acvl chain length of the non-polymerizable lipid affect the ... DMPC and DPPC was due to the long acyl chains of these lipids. ...

The number of water molecules bound to the dimyristoylphosphatidylcholine (DMPC) interface was investigated both in the fluid (L(alpha)) and gel (L(beta')) phases by solid state deuterium NMR of D2O. We determined that each DMPC molecule binds 9.7 +/- 0.5 and less than 4.3 +/- 0.5 D2O in the fluid and gel phases respectively. These results are accounted ...

Apolipophorin III (apoLp-III) from Locusta migratoria was employed as a model apolipoprotein to gain insight into binding interactions with lipid vesicles. Differential scanning calorimetry (DSC) was used to measure the binding interaction of apoLp-III with liposomes composed of mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and sphingomyelin (SM). Association ...

The role of lipid domain size and protein-lipid interfaces in the thermotropic phase transition of dipalmitoyl phosphatidylcholine (DPPC) and dimyristoyl phosphatidylcholine (DMPC) bilayers in Nanodiscs was studied using small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and generalized polarization (GP) of the lipophilic probe ...

Model-membrane systems composed of liquid-crystalline bicellar phases can be uniaxially oriented with respect to a magnetic field, thereby facilitating structural and dynamics studies of membrane-associated proteins. Here we quantitatively characterize a method that allows the manipulation of the direction of this uniaxial orientation. Bicelles formed from DMPC/DHPC are ...

Chronic usage of Non-steroidal anti-inflammatory drugs(NSAIDs) leads to gastrointestinal toxicity and clinical evidences point the cause to direct interactions between NSAIDs and phospholipid membranes. Also, NSAIDs pre-associated with phospholipid vesicles are shown to be safer and therapeutically more effective than unmodified ones. Our initial experiments and simulations on the partitioning of ...

We present a grazing-incidence small-angle X-ray scattering (GISAXS) study on 2D assembly of cowpea mosaic virus (CPMV) under a mixed cationic-zwitterionic (DMTAP^+-DMPC) lipid monolayer at the air-water interface. The inter-particle and particle-lipid electrostatic interactions were varied by controlling the subphase pH and the membrane charge density. ...

A phospholipid mixture consisting of dimyristoyl phosphatidylcholine (DMPC), dihexanoyl phosphatidylcholine (DHPC), and the negatively charged dimyristoyl phosphatidylglycerol (DMPG) lipid is found to spontaneously form uniform-size unilamellar vesicles (ULVs). Small angle neutron scattering (SANS) is used to examine ULV size as a function of net charge, ...

The potential physiological relevance of liquid-liquid phase separation in lipid membranes to the formation and stability of "lipid rafts" in cellular plasma membranes has prompted extensive investigation of the physical chemistry underlying these phenomena. In this contribution, the line tension (gamma) and dipole density differences ( micro) between demixed fluid phases of monolayers comprised ...

Phospholipid single bilayers supported on a hydrophilic solid substrate are extensively used in the study of the interaction between model membranes and proteins or polypeptides. In this article, the formation of a single dimyristoylphosphatidylcholine (DMPC) bilayer under an octadecyltrimethoxysilane (OTMS) polymerized Langmuir monolayer at the air-water interface is followed ...

The extent to which plasma HDL concentration regulates reverse cholesterol transport (RCT) is not known. The principal acceptors of unesterified cholesterol (UC) from cultured cells are small pre-beta-HDL, which we have shown increase in plasma during intravenous infusion of apolipoprotein A-I/phosphatidylcholine (apoA-I/PC) discs in ...

The in vivo metabolism of high density lipoprotein (HDL), labeled by incorporation of /sup 125/I-apolipoprotein (apo) A-IV, was studied in the rat and compared with the metabolism of HDL labeled with 131I-apo A-I. The /sup 125/I-apo A-IV labeled HDL was obtained by adding small amounts of radioiodinated apo A-IV to rat serum, followed by separation of the ...

The effects of different acylglycerides on the conformation and charge of apolipoprotein A-I (apoA-I) have been investigated in reconstituted high density lipoproteins (LpA-I). Various amounts of diacylglycerol (DG) and triacylglycerol (TG) were incorporated into sonicated spherical LpA-I particles containing 2 ...

Our aim was to characterize HDL subspecies and fat-soluble vitamin levels in a kindred with familial apolipoprotein A-I (apoA-I) deficiency. Sequencing of the APOA1 gene revealed a nonsense mutation at codon -2, Q[-2]X, with two documented homozygotes, eight heterozygotes, and two normal subjects in the kindred. Homozygotes presented markedly decreased HDL ...