Probabilistic Modelling of the Food Matrix Effects on Curcuminoid's In Vitro Oral Bioaccessibility.

The bioaccessibility of bioactive compounds plays a major role in the nutritional value of foods, but there is a lack of systematic studies assessing the effect of the food matrix on bioaccessibility. Curcuminoids are phytochemicals extracted from that have captured public attention due to claimed health benefits. The aim of this study is to develop a mathematical model to predict curcuminoid's bioaccessibility in biscuits and custard based on different fibre type formulations.

GFOGER Peptide Modifies the Protein Content of Extracellular Vesicles and Inhibits Vascular Calcification.

Objective: Vascular calcification (VC) is an active process during which vascular smooth muscle cells (VSMCs) undergo an osteogenic switch and release extracellular vesicles (EVs). In turn, the EVs serve as calcification foci via interaction with type 1 collagen (COL1). We recently showed that a specific, six-amino-acid repeat (GFOGER) in the sequence of COL1 was involved in the latter's interaction with integrins expressed on EVs.

The Impact of Plasma Membrane Lipid Composition on Flagellum-Mediated Adhesion of Enterohemorrhagic Escherichia coli.

Enterohemorrhagic (EHEC) O157:H7 is a major cause of foodborne gastrointestinal illness. The adhesion of EHEC to host tissues is the first step enabling bacterial colonization. Adhesins such as fimbriae and flagella mediate this process.

Methylation of Salmonella Typhimurium flagella promotes bacterial adhesion and host cell invasion.

The long external filament of bacterial flagella is composed of several thousand copies of a single protein, flagellin. Here, we explore the role played by lysine methylation of flagellin in Salmonella, which requires the methylase FliB. We show that both flagellins of Salmonella enterica serovar Typhimurium, FliC and FljB, are methylated at surface-exposed lysine residues by FliB.

Synthesis and characterization of tethered lipid assemblies for membrane protein reconstitution (Review).

Biological membranes and their related molecular mechanisms are essential for all living organisms. Membranes host numerous proteins and are responsible for the exchange of molecules and ions, cell signaling, and cell compartmentation. Indeed, the plasma membrane delimits the intracellular compartment from the extracellular environment and intracellular membranes.

Oligogalacturonic Acid Inhibits Vascular Calcification by Two Mechanisms: Inhibition of Vascular Smooth Muscle Cell Osteogenic Conversion and Interaction With Collagen.

Objective: Cardiovascular diseases constitute the leading cause of mortality worldwide. Calcification of the vessel wall is associated with cardiovascular morbidity and mortality in patients having many diseases, including diabetes mellitus, atherosclerosis, and chronic kidney disease. Vascular calcification is actively regulated by inductive and inhibitory mechanisms (including vascular smooth muscle cell adaptation) and results from an active osteogenic process.

Solid-phase extraction of betanin and isobetanin from beetroot extracts using a dipicolinic acid molecularly imprinted polymer.

Betanin is a natural pigment with significant antioxidant and biological activities currently used as food colorant. The isolation of betanin is problematic due to its instability. In this work, we developed a fast and economic procedure based on molecularly imprinted solid-phase extraction (MISPE) for the selective clean-up of betanin and its stereoisomer isobetanin from beetroot extracts.

Toward a Universal Method for Preparing Molecularly Imprinted Polymer Nanoparticles with Antibody-like Affinity for Proteins.

We describe a potentially universal, simple and cheap method to prepare water-compatible molecularly imprinted polymer nanoparticles (MIP-NPs) as synthetic antibodies against proteins. The strategy is based on a solid phase synthesis approach where glass beads (GBs) are functionalized with a metal chelate, acting as a general affinity ligand to attract surface-bound histidines present on proteins. This configuration enables an oriented immobilization of the proteins, upon which thermoresponsive MIP-NPs are synthesized.

Betanin-Enriched Red Beetroot (Beta vulgaris L.) Extract Induces Apoptosis and Autophagic Cell Death in MCF-7 Cells.

Recent studies have pointed out the preventive role of beetroot extracts against cancers and their cytotoxic activity on cancer cells. Among many different natural compounds, these extracts contained betanin and its stereoisomer isobetanin, which belongs to the betalain group of highly bioavailable antioxidants. However, a precise identification of the molecules responsible for this tumor-inhibitory effect was still required.

EGFR Inhibition by Curcumin in Cancer Cells: A Dual Mode of Action.

Epidermal Growth Factor Receptor (EGFR) is an important target of anticancer therapy. Nowadays, the search for new molecules inhibiting this receptor is turning toward natural substances. One of the most promising natural compounds that have shown an anti-EGFR activity is curcumin, a polyphenol found in turmeric.

Synergism of antioxidant action of vitamins E, C and quercetin is related to formation of molecular associations in biomembranes.

Vitamins E, C and polyphenols (flavonoids and non-flavonoids) are major natural antioxidants capable of preventing damage generated by oxidative stress. Here we show the capacity of these antioxidants to form non-covalent association within lipid bilayers close to the membrane/cytosol interface. Antioxidant regeneration is significantly enhanced in these complexes.

Real-time QCM-D monitoring of cancer cell death early events in a dynamic context.

Since a few years, the acoustic sensing of whole cell is the focus of increasing interest for monitoring the cytoskeletal cellular response to morphological modulators. We aimed at illustrating the potentialities of the quartz crystal microbalance with dissipation (QCM-D) technique for the real-time detection of the earliest morphological changes that occur at the cell-substrate interface during programmed cell death. Human breast cancer cells (MCF-7) grown on serum protein-coated gold sensors were placed in dynamic conditions under a continuous medium flow.

Bordetella pertussis adenylate cyclase toxin translocation across a tethered lipid bilayer.

Numerous bacterial toxins can cross biological membranes to reach the cytosol of mammalian cells, where they exert their cytotoxic effects. Our model toxin, the adenylate cyclase (CyaA) from Bordetella pertussis, is able to invade eukaryotic cells by translocating its catalytic domain directly across the plasma membrane of target cells. To characterize its original translocation process, we designed an in vitro assay based on a biomimetic membrane model in which a tethered lipid bilayer (tBLM) is assembled on an amine-gold surface derivatized with calmodulin (CaM).

Quartz crystal microbalance immunosensor for the quantification of immunoglobulin G in bovine milk.

The development of precise and sensitive methods for milk analysis remains a challenging task in the milk quality control field. A piezoelectric immunosensor was developed for the real-time quantification of immunoglobulin G (IgG) in bovine milk and colostrum. The sensing surface was designed with rabbit antibovine IgG as the detecting molecule, coupled onto a carboxymethyl dextran-coated gold crystal.

Autophosphorylation activation and inhibition by curcumin of the epidermal growth factor receptor reconstituted in liposomes.

The epidermal growth factor receptor (EGFR) is a 170-kDa transmembrane protein with intrinsic protein kinase activity. It is involved in the regulation of essential cellular processes such as proliferation, differentiation, survival, and migration. An increase in EGFR activity has been correlated to malignant evolution of the cells.

Enhanced cellular adhesion on titanium by silk functionalized with titanium binding and RGD peptides.

Soft tissue adhesion on titanium represents a challenge for implantable materials. In order to improve adhesion at the cell/material interface we used a new approach based on the molecular recognition of titanium by specific peptides. Silk fibroin protein was chemically grafted with titanium binding peptide (TiBP) to increase adsorption of these chimeric proteins to the metal surface.

A tethered bilayer assembled on top of immobilized calmodulin to mimic cellular compartmentalization.

Background: Biomimetic membrane models tethered on solid supports are important tools for membrane protein biochemistry and biotechnology. The supported membrane systems described up to now are composed of a lipid bilayer tethered or not to a surface separating two compartments: a "trans" side, one to a few nanometer thick, located between the supporting surface and the membrane; and a "cis" side, above the synthetic membrane, exposed to the bulk medium. We describe here a novel biomimetic design composed of a tethered bilayer membrane that is assembled over a surface derivatized with a specific intracellular protein marker.

Formation of tethered bilayer lipid membranes probed by various surface sensitive techniques.

Tethered bilayer lipid membranes are promising biomimetic architectures. Their formation has been investigated using four different surface sensitive techniques, including optical, acoustic, and electrical methods. The lipid bilayers are built in a two-step procedure; the proximal layer is formed by self-assembly and is then completed to a bilayer by fusion with small vesicles.

Quantification of immunoglobulin g in bovine and caprine milk using a surface plasmon resonance-based immunosensor.

Detection of colostrum in bovine and caprine milks is essential for dairy industries to avoid negative economical and technological consequences. One of the best markers of the presence of colostrum is immunoglobulin G (IgG). Two quantification methods have been evaluated for IgG in bovine or caprine milk, based on the real-time immunodetection of IgG by surface plasmon resonance (SPR) spectroscopy.

Exploring the membrane mechanism of the bioactive peptaibol ampullosporin a using lipid monolayers and supported biomimetic membranes.

Ampullosporin A is an antimicrobial, neuroleptic peptaibol, the behavior of which was investigated in different membrane mimetic environments made of egg yolk L-α-phosphatidylcholine. In monolayers, the peptaibol adopted a mixed α/3(10)-helical structure with an in-plane orientation. The binding step was followed by the peptide insertion into the lipid monolayer core.

Application of the Doehlert experimental design to molecularly imprinted polymers: surface response optimization of specific template recognition as a function of the type and degree of cross-linking.

We propose the use of Doehlert's experimental design, a second-order uniform shell design, for the optimization of molecularly imprinted polymers (MIPs). We have chosen a simple model system where the influence of kind and degree of cross-linking on template recognition was studied using S-propranolol as the template. We found that Doehlert's design allows--with very few experiments--one to screen the evolution of the binding capacity of a MIP as a function the different parameters, and thus appears to be a powerful means to screen for the best composition and synthesis method for MIPs.

Biomimetic tethered lipid membranes designed for membrane-protein interaction studies.

The complexity of the biological membranes restricts their direct investigation at the nanoscale. Lipid bilayer membranes have been developed as a model of biological membranes in order to allow the interaction and insertion of peptides and membrane proteins in a functional manner. Promising models have been developed in the past two decades and tethered bilayer design traduces constant improvement of membrane models.

Surface response methodology for the study of supported membrane formation.

We report on the investigations of the formation of the tethered lipid bilayer by vesicle deposition on amine-functionalized surfaces. The tethered bilayer was created by the deposition of egg-PC vesicles containing 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly-(ethyleneglycol)-N-hydroxysuccinimide as anchoring molecules on an amine-coated surface. This approach is an easy route for the formation of a biomimetic-supported membrane.

Voltage-dependent anion channel transports calcium ions through biomimetic membranes.

The mitochondrial outer membrane channel (VDAC), a central player in mitochondria and cell death, was reconstituted in polymer-supported phospholipid bilayers. Highly purified VDAC was first reconstituted in vesicles; channel properties and NADH-ferricyanide reductase activity were ascertained before deposition onto solid substrates. 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine/1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-N-hydroxysuccinimide mixed vesicles containing VDAC were linked onto amine-grafted surfaces (glass and gold) and disrupted to form a VDAC-containing polymer-tethered planar bilayer.