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Ganglioside GM3 stimulates lipid-protein co-assembly in α-synuclein amyloid formation

Parkinson's disease is characterized by the aggregation of the presynaptic protein α-synuclein (αSyn), and its co-assembly with lipids and other cellular matter in the brain. Here we investigated lipid-protein co-assembly in a system composed of αSyn and model membranes containing the glycolipid ganglioside GM3. We quantified the uptake of lipids into the co-assembled aggregates and investigated h

Hydrophobic homopolymers of native α-L-amino acids at the air-water interface : A study by circular dichroism spectroscopy, atomic force microscopy, and surface balance experiments

Films of poly-L-leucine, poly-L-valine, and poly-L-isoleucine have been studied at the air-water interface by surface balance experiments. In addition, Langmuir-Blodgett (LB) films of these polypeptides deposited onto quartz and mica have been studied by circular dichroism (CD) spectroscopy and atomic force microscopy (AFM) to elucidate the effects of polypeptide conformation and spreading agent (

AFM study of lipid monolayers : III. Phase behavior of ceramides, cholesterol and fatty acids

The outer part of the skin, stratum corneum, is essential to the skin's barrier function. Monolayer and bulk phase behavior of stratum corneum model lipids have thus been studied. Domain formation in Langmuir-Blodgett monolayers of synthetic ceramides (C16CerIII and C24CerIII), cholesterol, and free fatty acids (lignoceric acid, C24:0, and palmitic acid, C16:0) were investigated by atomic force mi

Responding phospholipid membranes : Interplay between hydration and permeability

Osmotic forces are important in regulating a number of physiological membrane processes. The effect of osmotic pressure on lipid phase behavior is of utmost importance for the extracellular lipids in stratum corneum (the outer part of human skin), due to the large gradient in water chemical potential between the water-rich tissue on the inside, and the relative dry environment on the outside of th

Diffusion through a responding lamellar liquid crystal : A model of molecular transport across stratum corneum

The outer part of the skin, stratum corneum, has an architecture of keratin filled cells, the corneocytes, embedded in stacked lipid bilayers. The lamellar structure provides an effective barrier to passive diffusion of small molecules and prevents uncontrolled water loss. In this paper, we present a theoretical model for molecular diffusional transport over an oriented stack of liquid crystalline

Rectangular solid domains in ceramide-cholesterol monolayers - 2D crystals

Very small rectangular domains were observed by atomic force microscopy in binary monolayers of synthetic ceramides and cholesterol. When the cholesterol content is increased the domains are bigger although the rectangular shape is retained. The almost perfect shape of the domains indicates two-dimensional single ceramide crystals. Lipid domains in monolayers of this particular shape and size have

The skin barrier from a lipid perspective

This contribution summarises the results from a number of investigations undertaken in the spirit of the Domain Mosaic Model proposed by Forslind in 1994. Atomic Force Microscopy (AFM) studies on the two-dimensional phase behaviour of some stratum corneum lipids revealed phase separation of the lipids in the typical case and the ability of cholesterol to reduce the line tension between phases. A t

Development of supramolecular structure through alkylation of pendant pyridyl functionality

The complex 12+ which has two pendant 4-pyridyl substituents may be viewed as a metal-containing analogue of 4,4′-bipyridine. The complex undergoes N-alkylation reactions with a variety of alkylating agents to give more highly functionalised tetracationic complexes which may be termed metalloviologens by analogy with viologens. These complexes may also be prepared by alkylation of the free ligands

Reaction of [Os3H2(CO)10] with the diyne Me3SiC2C2SiMe3 and the reactivity of the products towards [Co2(CO)8] : The X-ray structures of [Os3(μ-H)(CO)10 {μ-η12-HC2 (SiMe3)C2(SiMe3)}],[Os3

The reaction of [Os3H2(CO)10] with Me3SiC2C2SiMe3 affords both [Os3(μ-H) (CO)10{μ-η1-η2-HC 2(SiMe3)C2(SiMe3)}] (1) and [Os3(μ-CO)(CO)9(μ3-η 2-Me3SiC2C2SiMe3)] (2) in good yield, 2 being favoured with an excess of diyne. In 1, one edge of the triosmium unit is bridged by the vinyl moiety of a transformed bis(trimethylsilyl)-1,4-butadiyne ligand that has undergone a hydride transfer and a 1,2-trimet

AFM study of lipid monolayers. 2. Effect of cholesterol on fatty acids

In this study the effect of cholesterol in Langmuir-Blodgett monolayers of fatty acids of varying chain lengths was investigated by atomic force microscopy (AFM). Domain formation due to lateral phase separation was studied at different lipid compositions and surface pressures. A small amount of cholesterol is miscible with palmitic acid (C16:0) and forms a flat monolayer while excess cholesterol

AFM study of lipid monolayers. 1. Pressure-induced phase behavior of single and mixed fatty acids

Monolayers of palmitic (C16:0) and lignoceric acid (C24:0) and their equimolar mixture were transferred to a hydrophilic mica substrate at various surface pressures and investigated by means of atomic force microscopy (AFM) in contact and lateral force modes. The first-order transition of lignoceric acid gives a plateau region, representing a liquid expanded to liquid condensed phase transition in

Dear territory or dear partner? Causes and consequences of breeding dispersal in a highly territorial bird of prey with a strong pair bond

Abstract: Territorial species are unlikely to show extensive movements between breeding seasons. This is especially true for long-lived species, which often have strong pair bonding and can occupy the same territory for years. However, also in such species, individuals may face situations that can lead to a territory shift. Here, we use a comprehensive dataset documenting 40 years of breeding beha

Impacts of large-scale Saharan solar farms on the global terrestrial carbon cycle

Amassing the available solar energy over the Sahara desert, through the installation of a large-scale solar farm, would satisfy the world’s current electricity needs. However, such land use changes may affect the global carbon cycle, possibly offsetting mitigation efforts. Here a fully coupled Earth System model EC-Earth was used to investigate the impact of a Saharan solar farm on the terrestrial

Metoprolol disrupts inflammatory response of human cardiomyocytes via β-arrestin2 biased agonism and NF-κB signaling modulation

Aims: Recent evidence supports non-class cardioprotective effects of metoprolol against neutrophil-mediated ischemia-reperfusion injury during exacerbated inflammation. Whether metoprolol exerts direct anti-inflammatory effect on cardiomyocytes is unknown. Accordingly, we aimed to investigate the direct anti-inflammatory effects of metoprolol in a cellular model of human induced pluripotent stem c

Influence of genetic variants and sialylation of purified κ-casein on peptide release during in vitro digestion

In the present study, digestion pattern of purified bovine κ-casein (κ-CN) variants A, B, E as well as desialylated variant B, using INFOGEST 2.0 in vitro gastrointestinal digestion were investigated using peptidomics. Peptide profiles of the digests were identified and quantified using ion abundancies by liquid chromatography electrospray quadropole time of flight mass spectrometry (LC-ESI/Q-TOF

Sintering in seconds, elucidated by millisecond in situ diffraction

Materials, when sintered at high temperatures, undergo structural changes on multiple, hierarchical length scales but getting realtime information on these changes is difficult. To address this challenge, we developed a custom-built sample environment that allows us to investigate the structural evolution of materials during sintering using high-energy two-dimensional synchrotron X-ray diffraction

In vivo hepatic flow distribution by computational fluid dynamics can predict pulmonary flow distribution in patients with Fontan circulation

In Fontan patients, a lung deprived of hepatic blood may develop pulmonary arterio-venous malformations (PAVMs) resulting in shunting, reduced pulmonary vascular resistance (PVR) and decreased oxygenation. To provide guidance for corrective invasive interventions, we aimed to non-invasively determine how the hepatic to pulmonary blood flow balance correlates with pulmonary flow, PVR, and with oxyg