Granular architecture of lotus seed starch and its impact on physicochemical properties.

Lotus seed starch has high apparent amylose content (AAM). A representative definition of its granular architecture (e.g., lamellar structure) remained absent. This study defined the granular shape, crystalline and lamellar structures, and digestibility of twenty-two samples of lotus seed starch (LS) by comparing with those of potato and maize starches. LS granules had more elongated shape and longer repeat distance of lamellae than potato and maize starch granules. The enzymatic susceptibility of LS granules was more affected by AAM than granular architecture. Using these LSs as a model system, the relationships between lamellar structure of starch granules and properties of their gelatinized counterparts were investigated. In LSs, thinner amorphous lamella and thicker crystalline lamella were associated with higher swelling power and yield stress. The relationships were found to be connected via certain structural characteristics of amylopectin.

In Situ Ultra-Small- and Small-Angle X-ray Scattering Study of ZnO Nanoparticle Formation and Growth through Chemical Bath Deposition in the Presence of Polyvinylpyrrolidone.

ZnO inverse opals combine the outstanding properties of the semiconductor ZnO with the high surface area of the open-porous framework, making them valuable photonic and catalysis support materials. One route to produce inverse opals is to mineralize the voids of close-packed polymer nanoparticle templates by chemical bath deposition (CBD) using a ZnO precursor solution, followed by template removal. To ensure synthesis control, the formation and growth of ZnO nanoparticles in a precursor solution containing the organic additive polyvinylpyrrolidone (PVP) was investigated by in situ ultra-small- and small-angle X-ray scattering (USAXS/SAXS). Before that, we studied the precursor solution by in-house SAXS at T = 25 °C, revealing the presence of a PVP network with semiflexible chain behavior. Heating the precursor solution to 58 °C or 63 °C initiates the formation of small ZnO nanoparticles that cluster together, as shown by complementary transmission electron microscopy images (TEM) taken after synthesis. The underlying kinetics of this process could be deciphered by quantitatively analyzing the USAXS/SAXS data considering the scattering contributions of particles, clusters, and the PVP network. A nearly quantitative description of both the nucleation and growth period could be achieved using the two-step Finke-Watzky model with slow, continuous nucleation followed by autocatalytic growth.

Critical nanomaterial attributes of iron-carbohydrate nanoparticles: Leveraging orthogonal methods to resolve the 3-dimensional structure.

Intravenous iron-carbohydrate nanomedicines are widely used to treat iron deficiency and iron deficiency anemia across a wide breadth of patient populations. These colloidal solutions of nanoparticles are complex drugs which inherently makes physicochemical characterization more challenging than small molecule drugs. There have been advancements in physicochemical characterization techniques such as dynamic light scattering and zeta potential measurement, that have provided a better understanding of the physical structure of these drug products in vitro. However, establishment and validation of complementary and orthogonal approaches are necessary to better understand the 3-dimensional physical structure of the iron-carbohydrate complexes, particularly with regard to their physical state in the context of the nanoparticle interaction with biological components such as whole blood (i.e. the nano-bio interface).

Unorthodox PCNA Binding by Chromatin Assembly Factor 1.

The eukaryotic DNA replication fork is a hub of enzymes that continuously act to synthesize DNA, propagate DNA methylation and other epigenetic marks, perform quality control, repair nascent DNA, and package this DNA into chromatin. Many of the enzymes involved in these spatiotemporally correlated processes perform their functions by binding to proliferating cell nuclear antigen (PCNA). A long-standing question has been how the plethora of PCNA-binding enzymes exert their activities without interfering with each other. As a first step towards deciphering this complex regulation, we studied how Chromatin Assembly Factor 1 (CAF-1) binds to PCNA. We demonstrate that CAF-1 binds to PCNA in a heretofore uncharacterized manner that depends upon a cation-pi (π) interaction. An arginine residue, conserved among CAF-1 homologs but absent from other PCNA-binding proteins, inserts into the hydrophobic pocket normally occupied by proteins that contain canonical PCNA interaction peptides (PIPs). Mutation of this arginine disrupts the ability of CAF-1 to bind PCNA and to assemble chromatin. The PIP of the CAF-1 p150 subunit resides at the extreme C-terminus of an apparent long α-helix (119 amino acids) that has been reported to bind DNA. The length of that helix and the presence of a PIP at the C-terminus are evolutionarily conserved among numerous species, ranging from yeast to humans. This arrangement of a very long DNA-binding coiled-coil that terminates in PIPs may serve to coordinate DNA and PCNA binding by CAF-1.

The development of new oral vaccines using porous silica.

Ordered mesoporous silica (OMS) was proved to be an efficient oral adjuvant capable to deliver a wide in size variety of different antigens, promoting efficient immunogenicity. This material can be used in single or polivalent vaccines, which have been developed by a group of Brazilian scientists. The experiments performed with the model protein Bovine Serum Albumin (BSA) gave the first promissing results, that were also achieved by testing the virus like particle surface antigen of hepatitis B (HBsAg) and diphtheria anatoxin (dANA). Nanostructured OMS, SBA-15 type, with bi-dimensional hexagonal porous symmetry was used to encapsulate the antigens either in the mesoporous (pore diameter ∼ 10 nm) or macroporous (pore diameter > 50 nm) regions. This silica vehicle proved to be capable to create an inflammatory response, did not exhibit toxicity, being effective to induce immunity in high and low responder mice towards antibody production. The silica particles are in the range of micrometer size, leaving no trace in mice organs due to its easy expulsion by faeces. The methods of physics, usually employed to characterize the structure, composition and morphology of materials are of fundamental importance to develop proper oral vaccines in order to state the ideal antigen load to avoid clustering and to determine the rate of antigen release in different media mimicking body fluids.

Computational and SAXS-based structure insights of pectin acetyl esterase (CtPae12B) of family 12 carbohydrate esterase from Clostridium thermocellum ATCC 27405.

Pectin is a complex form of polysaccharide and is composed of several structural components that require the concerted action of several pectinases for its complete degradation. In this study, in silico and solution structure of a pectin acetyl esterase (CtPae12B) of family 12 carbohydrate esterase (CE12) from Clostridium thermocellum was determined. The CtPae12B modelled structure, showed a new α/ß hydrolase fold, similar to the fold found in the crystal structures of its nearest homologues from CE12 family, which differed from α/ß hydrolase fold found in glycoside hydrolases. In the active site of CtPae12B, two loops (loop1 and loop6) play an important role in the formation of a catalytic triad Ser15-Asp187-His190, where Ser15 acts as a nucleophile. The structural stability of CtPae12B and its catalytic site was detected by performing molecular dynamic (MD) simulation which showed stable and compact conformation of the structure. Molecular docking method was employed to analyse the conformations of various suitable ligands docked at the active site of CtPae12B. The stability and structural specificity of the catalytic residues with the ligand, 4-nitrophenyl acetate (4-NPA) was confirmed by MD simulation of CtPae12B-4NPA docked complex. Moreover, it was found that the nucleophile Ser15, forms hydrophobic interaction with 4-NPA in the active site to complete covalent catalysis. Small angle X-ray scattering analysis of CtPae12B at 3 mg/mL displayed elongated, compact and monodispersed nature in solution. The ab initio derived dummy model showed that CtPae12B exists as a homotrimer at 3 mg/mL which was also confirmed by dynamic light scattering.Communicated by Ramaswamy H. Sarma.

Integrated Structural Studies for Elucidating Carotenoid-Protein Interactions.

Carotenoids are ancient pigment molecules that, when associated with proteins, have a tremendous range of functional properties. Unlike most protein prosthetic groups, there are no recognizable primary structure motifs that predict carotenoid binding, hence the structural details of their amino acid interactions in proteins must be worked out empirically. Here we describe our recent efforts to combine complementary biophysical methods to elucidate the precise details of protein-carotenoid interactions in the Orange Carotenoid Protein and its evolutionary antecedents, the Helical Carotenoid Proteins (HCPs), CTD-like carotenoid proteins (CCPs).

Influence of humectants on the thermotropic behaviour and nanostructure of fully hydrated lecithin bilayers.

Humectants are used widely in topical formulations as they provide cosmetic and health benefits to skin. Of particular interest to our laboratories is the interaction of humectants in phospholipid based topical skin care formulations. This study probed the effects of three exemplary humectants on a fully hydrated lecithin system (DPPC) by use of X-ray scattering and differential scanning calorimetry. While the three humectants affected the nanostructure of 1, 2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC, bilayers in a similar manner, leading to an increased membrane order, differences in the effect on the thermal behaviour of DPPC suggest that betaine and sarcosine interacted via a different mechanism compared to acetic monoethanolamide, AMEA. At concentrations above 0.4 M, betaine and sarcosine stabilised the gel phase by depletion of the interfacial water via the preferential exclusion mechanism. At the same time, a slight increase in the rigidity of the membrane was observed with an increase in the membrane thickness. Overall, the addition of betaine or sarcosine resulted in an increase in the pre- and main transition temperatures of DPPC. AMEA, on the other hand, decreases both transition temperatures, and although the interlamellar water layer was also decreased, there was evidence from the altered lipid chain packing, that AMEA molecules are present also at the bilayer interface, at least at high concentrations. Above the melting point in the fluid lamellar phase, none of the humectants induced significant structural changes, neither concerning the bilayer stacking order nor its overall membrane fluidity. An humectant-induced increase in the Hamaker constant is the most plausible explanation for the observed reduction of the inter-bilayer distances, both in the gel and fluid phase.

The Cytoplasmic Tail of Influenza A Virus Hemagglutinin and Membrane Lipid Composition Change the Mode of M1 Protein Association with the Lipid Bilayer.

Influenza A virus envelope contains lipid molecules of the host cell and three integral viral proteins: major hemagglutinin, neuraminidase, and minor M2 protein. Membrane-associated M1 matrix protein is thought to interact with the lipid bilayer and cytoplasmic domains of integral viral proteins to form infectious virus progeny. We used small-angle X-ray scattering (SAXS) and complementary techniques to analyze the interactions of different components of the viral envelope with M1 matrix protein. Small unilamellar liposomes composed of various mixtures of synthetic or "native" lipids extracted from Influenza A/Puerto Rico/8/34 (H1N1) virions as well as proteoliposomes built from the viral lipids and anchored peptides of integral viral proteins (mainly, hemagglutinin) were incubated with isolated M1 and measured using SAXS. The results imply that M1 interaction with phosphatidylserine leads to condensation of the lipid in the protein-contacting monolayer, thus resulting in formation of lipid tubules. This effect vanishes in the presence of the liquid-ordered (raft-forming) constituents (sphingomyelin and cholesterol) regardless of their proportion in the lipid bilayer. We also detected a specific role of the hemagglutinin anchoring peptides in ordering of viral lipid membrane into the raft-like one. These peptides stimulate the oligomerization of M1 on the membrane to form a viral scaffold for subsequent budding of the virion from the plasma membrane of the infected cell.

Multiscale and multimodal X-ray analysis: Quantifying phase orientation and morphology of mineralized turkey leg tendons.

Fibrous biocomposites like bone and tendons exhibit a hierarchical arrangement of their components ranging from the macroscale down to the molecular level. The multiscale complex morphology, together with the correlated orientation of their constituents, contributes significantly to the outstanding mechanical properties of these biomaterials. In this study, a systematic road map is provided to quantify the hierarchical structure of a mineralized turkey leg tendon (MTLT) in a holistic multiscale evaluation by combining micro-Computed Tomography (micro-CT), small-angle X-ray scattering (SAXS), and wide-angle X-ray diffraction (WAXD). We quantify the interplay of the main MTLT components with respect to highly ordered organic parts such as fibrous collagen integrating inorganic components like hydroxyapatite (HA). The microscale fibrous morphology revealing different types of porous features and their orientation was quantified based on micro-CT investigations. The quantitative analysis of the alignment of collagen fibrils and HA crystallites was established from the streak-like signal in SAXS using the Ruland approach and the broadening of azimuthal profiles of the small and wide-angle diffraction peaks. It has been in general agreement that HA crystallites are co-aligned with the nanostructure of mineralized tissue. However, we observe relatively lower degree of orientation of HA crystallites compared to the collagen fibrils, which supports the recent findings of the structural interrelations within mineralized tissues. The generic multiscale characterization approach of this study is relevant to any hierarchically structured biomaterials or bioinspired materials from the µm-nm-Å scale. Hence, it gives the basis for future structure-property relationship investigations and simulations for a wide range of hierarchically structured materials. STATEMENT OF SIGNIFICANCE: Many fibrous biocomposites such as tendon, bone, and wood possess multiscale hierarchical structures, responsible for their exceptional mechanical properties. In this study, the 3-dimensional hierarchical structure, the degree of orientation and composition of mineralized tendon extracted from a turkey leg were quantified using a multimodal X-ray based approach combining small-angle X-ray scattering and wide-angle X-ray diffraction with micro-Computed Tomography. We demonstrate that hydroxyapatite (HA) domains are co-aligned with the nanostructure of mineralized tissue. However, the lower degree of orientation of HA crystallites was observed when compared to the collagen fibrils. The generic multiscale characterization approach of this study is relevant to any hierarchically structured biomaterials or bioinspired materials from the micrometer over the nanometer to the Angström scale level.

Evaluation of novobiocin and telmisartan for anti-CHIKV activity.

Chikungunya has re-emerged as an epidemic with global distribution and high morbidity, necessitating the need for effective therapeutics. We utilized already approved drugs with a good safety profile used in other diseases for their new property of anti-chikungunya activity. It provides a base for a fast and efficient approach to bring a novel therapy from bench to bedside by the process of drug-repositioning. We utilized an in-silico drug screening with FDA approved molecule library to identify inhibitors of the chikungunya nsP2 protease, a multifunctional and essential non-structural protein required for virus replication. Telmisartan, an anti-hypertension drug, and the antibiotic novobiocin emerged among top hits on the screen. Further, SPR experiments revealed strong in-vitro binding of telmisartan and novobiocin to nsP2 protein. Additionally, small angle x-ray scattering suggested binding of molecules to nsP2 and post-binding compaction and retention of monomeric state in the protein-inhibitor complex. Protease activity measurement revealed that both compounds inhibited nsP2 protease activity with IC50 values in the low micromolar range. More importantly, plaque formation assays could show the effectiveness of these drugs in suppressing virus propagation in host cells. We propose novobiocin and telmisartan as potential inhibitors of chikungunya replication. Further research is required to establish the molecules as antivirals of clinical relevance against chikungunya.

A novel experimental approach for nanostructure analysis: simultaneous small-angle X-ray and neutron scattering.

Exploiting small-angle X-ray and neutron scattering (SAXS/SANS) on the same sample volume at the same time provides complementary nanoscale structural information in two different contrast situations. Unlike an independent experimental approach, the truly combined SAXS/SANS experimental approach ensures the exactness of the probed samples, particularly for in situ studies. Here, an advanced portable SAXS system that is dimensionally suitable for installation in the D22 zone of ILL is introduced. The SAXS apparatus is based on a Rigaku switchable copper/molybdenum microfocus rotating-anode X-ray generator and a DECTRIS detector with a changeable sample-to-detector distance of up to 1.6 m in a vacuum chamber. A case study is presented to demonstrate the uniqueness of the newly established method. Temporal structural rearrangements of both the organic stabilizing agent and organically capped gold colloidal particles during gold nanoparticle growth are simultaneously probed, enabling the immediate acquisition of correlated structural information. The new nano-analytical method will open the way for real-time investigations of a wide range of innovative nanomaterials and will enable comprehensive in situ studies on biological systems. The potential development of a fully automated SAXS/SANS system with a common control environment and additional sample environments, permitting a continual and efficient operation of the system by ILL users, is also introduced.

Topotecan effect on the structure of normal and cancer plasma membrane lipid models: A multi-model approach.

Topotecan is a relatively large, planar, asymmetric and polar molecule with a lactone moiety. In neutral or basic aqueous solutions, this ring opens forming the carboxylate form of Topotecan that is biologically inactive and uncapable of passively cross membranes. Nevertheless, despite this inability to cross membranes at this form, Topotecan may still be able to interact with phospholipid bilayers, disturbing them. In this context, phospholipid models, mimicking normal (DMPC at pH 7.4) and cancer cell lipid membranes (DMPC:DMPS (5:1) at pH 6.5), were used to assess structural modifications upon interaction with Topotecan. Langmuir isotherms of monolayers coupled with Brewster angle microscopy, differential scanning calorimetry of liposomes and X-ray scattering of small and wide angle of stacked multilayers were used as complementary techniques. The overall results show that the interaction of Topotecan with lipid membranes is deeply conditioned by their composition and that Topotecan seems to have a preferential interaction with the glycerol backbone of phosphatidylcholine phospholipids.

Identification of a novel tetrameric structure for human apolipoprotein-D.

Apolipoprotein-D is a 25 kDa glycosylated member of the lipocalin family that folds into an eight-stranded ß-barrel with a single adjacent α-helix. Apolipoprotein-D specifically binds a range of small hydrophobic ligands such as progesterone and arachidonic acid and has an antioxidant function that is in part due to the reduction of peroxidised lipids by methionine-93. Therefore, apolipoprotein-D plays multiple roles throughout the body and is protective in Alzheimer's disease, where apolipoprotein-D overexpression reduces the amyloid-ß burden in Alzheimer's disease mouse models. Oligomerisation is a common feature of lipocalins that can influence ligand binding. The native structure of apolipoprotein-D, however, has not been conclusively defined. Apolipoprotein-D is generally described as a monomeric protein, although it dimerises when reducing peroxidised lipids. Here, we investigated the native structure of apolipoprotein-D derived from plasma, breast cyst fluid (BCF) and cerebrospinal fluid. In plasma and cerebrospinal fluid, apolipoprotein-D was present in high-molecular weight complexes, potentially in association with lipoproteins. In contrast, apolipoprotein-D in BCF formed distinct oligomeric species. We assessed apolipoprotein-D oligomerisation using native apolipoprotein-D purified from BCF and a suite of complementary methods, including multi-angle laser light scattering, analytical ultracentrifugation and small-angle X-ray scattering. Our analyses showed that apolipoprotein-D predominantly forms a ∼95 to ∼100 kDa tetramer. Small-angle X-ray scattering analysis confirmed these findings and provided a structural model for apolipoprotein-D tetramer. These data indicate apolipoprotein-D rarely exists as a free monomer under physiological conditions and provide insights into novel native structures of apolipoprotein-D and into oligomerisation behaviour in the lipocalin family.

A trapped human PPM1A-phosphopeptide complex reveals structural features critical for regulation of PPM protein phosphatase activity.

Metal-dependent protein phosphatases (PPM) are evolutionarily unrelated to other serine/threonine protein phosphatases and are characterized by their requirement for supplementation with millimolar concentrations of Mg2+ or Mn2+ ions for activity in vitro The crystal structure of human PPM1A (also known as PP2Cα), the first PPM structure determined, displays two tightly bound Mn2+ ions in the active site and a small subdomain, termed the Flap, located adjacent to the active site. Some recent crystal structures of bacterial or plant PPM phosphatases have disclosed two tightly bound metal ions and an additional third metal ion in the active site. Here, the crystal structure of the catalytic domain of human PPM1A, PPM1Acat, complexed with a cyclic phosphopeptide, c(MpSIpYVA), a cyclized variant of the activation loop of p38 MAPK (a physiological substrate of PPM1A), revealed three metal ions in the active site. The PPM1Acat D146E-c(MpSIpYVA) complex confirmed the presence of the anticipated third metal ion in the active site of metazoan PPM phosphatases. Biophysical and computational methods suggested that complex formation results in a slightly more compact solution conformation through reduced conformational flexibility of the Flap subdomain. We also observed that the position of the substrate in the active site allows solvent access to the labile third metal-binding site. Enzyme kinetics of PPM1Acat toward a phosphopeptide substrate supported a random-order, bi-substrate mechanism, with substantial interaction between the bound substrate and the labile metal ion. This work illuminates the structural and thermodynamic basis of an innate mechanism regulating the activity of PPM phosphatases.

Time-Resolved Small-Angle X-ray Scattering Reveals Millisecond Transitions of a DNA Origami Switch.

Self-assembled DNA structures enable creation of specific shapes at the nanometer-micrometer scale with molecular resolution. The construction of functional DNA assemblies will likely require dynamic structures that can undergo controllable conformational changes. DNA devices based on shape complementary stacking interactions have been demonstrated to undergo reversible conformational changes triggered by changes in ionic environment or temperature. An experimentally unexplored aspect is how quickly conformational transitions of large synthetic DNA origami structures can actually occur. Here, we use time-resolved small-angle X-ray scattering to monitor large-scale conformational transitions of a two-state DNA origami switch in free solution. We show that the DNA device switches from its open to its closed conformation upon addition of MgCl2 in milliseconds, which is close to the theoretical diffusive speed limit. In contrast, measurements of the dimerization of DNA origami bricks reveal much slower and concentration-dependent assembly kinetics. DNA brick dimerization occurs on a time scale of minutes to hours suggesting that the kinetics depend on local concentration and molecular alignment.

Reverse micelles as nanocarriers of nisin against foodborne pathogens.

Reverse micelles (RMs) as nanocarriers of nisin were optimized for the highest water and bacteriocin content. RMs formulated with either refined olive oil or sunflower oil, distilled monoglycerides, ethanol, and water were effectively designed. Structural characterization of the RMs was assessed using Electron Paramagnetic Resonance Spectroscopy and Small Angle X-ray Scattering in the presence and absence of nisin. No conformational changes occurred in the presence of nisin for the nanocarriers. To assess efficacy of the loaded systems, their antimicrobial activity against Staphylococcus aureus and Listeria monocytogenes was tested in lettuce leaves and minced meat, respectively. Antimicrobial activity was evident in both cases. Interestingly, a synergistic antimicrobial effect was observed in lettuce leaves and to a lesser extent in minced meat between nisin and some of the nanocarriers' constituents (probably ethanol). Our findings suggest complex interactions that take place when RMs are applied in different food matrices.

Hybrid Methods for Modeling Protein Structures Using Molecular Dynamics Simulations and Small-Angle X-Ray Scattering Data.

Small-angle X-ray scattering (SAXS) is an efficient experimental tool to measure the overall shape of macromolecular structures in solution. However, due to the low resolution of SAXS data, high-resolution data obtained from X-ray crystallography or NMR and computational methods such as molecular dynamics (MD) simulations are complementary to SAXS data for understanding protein functions based on their structures at atomic resolution. Because MD simulations provide a physicochemically proper structural ensemble for flexible proteins in solution and a precise description of solvent effects, the hybrid analysis of SAXS and MD simulations is a promising method to estimate reasonable solution structures and structural ensembles in solution. Here, we review typical and useful in silico methods for modeling three dimensional protein structures, calculating theoretical SAXS profiles, and analyzing ensemble structures consistent with experimental SAXS profiles. We also review two examples of the hybrid analysis, termed MD-SAXS method in which MD simulations are carried out without any knowledge of experimental SAXS data, and the experimental SAXS data are used only to assess the consistency of the solution model from MD simulations with those observed in experiments. One example is an investigation of the intrinsic dynamics of EcoO109I using the computational method to obtain a theoretical profile from the trajectory of an MD simulation. The other example is a structural investigation of the vitamin D receptor ligand-binding domain using snapshots generated by MD simulations and assessment of the snapshots by experimental SAXS data.

Microstructure evaluation of dermally applicable liquid crystals as a function of water content and temperature: Can electron paramagnetic resonance provide complementary data?

Insight into the microstructure of lyotropic liquid crystals (LCs) is of crucial importance for development of novel dermal delivery systems. Our aim was to evaluate the phase behaviour of dermally applicable LCs composed of isopropyl myristate/Tween 80/lecithin/water, along the dilution line, where phase transitions are predominantly driven by increased water content. Additionally, identification of LC temperature dependence is of great importance for skin application. Selected LCs were evaluated using electron paramagnetic resonance (EPR) plus conventionally used methods of polarization microscopy, small-angle X-ray scattering, differential scanning calorimetry, and rheological measurements. Depending on water content, LCs formed diverse microstructures, from (pseudo)hexagonal (LC1) and lamellar (LC2-LC7) liquid crystalline phases that possibly co-exist with rod-like micelles (LC4-LC7), to a transitional micellar phase (LC8). Furthermore, the LCs microstructure remained unaltered within the tested temperature range. EPR was shown to detect microstructural transitions of LCs and to provide complementary data to other techniques. These data thus confirm the applicability of EPR as a complementary technique for better understanding of LC microstructural transitions that are expected to contribute greatly to studies oriented towards the drug release characteristics from such systems.

Micellization in vegetable oils: A structural characterisation.

The solubilisation of polar and polyphenol antioxidant in vegetable oils was studied. It was shown that the use of a polyglyceryl-3-diisostearate (PG3DS), a bio-sourced emulsifier well known in cosmetics, increases the yield of solubilisation thanks to some aggregation properties analysed using x-ray scattering technique. We show indeed that PG3DS forms reverse aggregates with a critical concentration that depends on the oil polarity. PG3DS reverse aggregates are elongated with a polar core and cannot be really swollen by addition of water. This supramolecular organisation allows however an efficient solubilisation of polar antioxidants in vegetable oils.