References of "Nasir, Mehmet Nail"
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See detailMembrane interactions of cyclic lipodepsipeptides from the viscosin group
Geudens, Niels; Feher, Krisztina; De Vleeschouwer et al

Poster (2014, June)

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See detailModeling of the Iturinic Antimicrobial Lipopeptide Mycosubtilin at Interfaces
Loison, Claire; Nasir, Mehmet Nail ULg; Benichou, Emmanuel et al

Conference (2014, June)

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See detailInteractions between new phenolic glycolipids and model membrane
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Crowet, Jean-Marc ULg et al

Poster (2014, February 07)

Model membrane based on phospholipids (PL) layers are useful to mimic properties of plasma membranes. The interactions between new synthesized phenolic glycolipids (PGL) and biological membrane are ... [more ▼]

Model membrane based on phospholipids (PL) layers are useful to mimic properties of plasma membranes. The interactions between new synthesized phenolic glycolipids (PGL) and biological membrane are crucial to determine their potential as drug candidates and their cytotoxicity . [less ▲]

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See detailInteractions of a potential plant elicitor mannolipid with plant model membranes
Polo Lozano, Damien ULg; Lins, Laurence ULg; Ongena, Marc ULg et al

Poster (2014, February 07)

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act ... [more ▼]

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act on the plants by inducing systemic resistance against diseases caused by fungal, viral, bacterial agents and insects. The target of the elicitors is supposed to be the plant plasma membranes (PPM). The main mechanisms of interaction of many elicitors involve proteic receptors but lipid-based elicitors (LBE) may preferably interact with the lipidic fractions of PPM. However there is no detailed information at the molecular level on the PPM-LBE interactions. Our work is focused on a original synthetic LBE composed of a mannoside linked to a myristic acid. It has potential elicitor activities as shown by the assays on tobacco root cells. These activities could be related to its interaction with the lipidic phase of PPM. Since PPM are complex entities, the analyses of the PPM- molecule interactions are quite difficult. In this context, these interactions were carried out using biomimetic membranes of PPM such as Langmuir monolayers and multilayers. The effects of our molecule on these membranar systems were investigated by biophysical and in silico approaches. [less ▲]

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See detailNew alternatives to chemical pesticides: deciphering the action mechanisms of lipid based plant elicitors via complementary biophysical and biological approaches.
Nasir, Mehmet Nail ULg; Polo Lozano, Damien ULg; Luzuriaga Loaiza, Walter ULg et al

Poster (2014, February)

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among ... [more ▼]

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among biopesticides, elicitor molecules which are able to trigger immune defense responses in plants are one of the most promising options. Although numerous elicitors have been discovered, the mechanisms involved in the perception, by plants, of only a few molecules have been identified. These elicitors usually interact with proteic receptors but we have recently shown that they may also act on the lipid phase of the plasma membrane. This project first aims to improve our understanding of the molecular mechanisms involved in the recognition of specific lipid based elicitors (LBE). On that basis, the FIELD project will contribute to the design and the development of innovative compounds derived natural LBE. A multi-disciplinary approach, based on chemistry, bio-physics, bio-chemistry, and phytopathology will be followed by a consortium of different research groups from Gembloux Agro-Bio Tech in close collaboration with teams from foreign institutions. [less ▲]

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See detailExploration on structure activity relation of natural, self-assembling cyclic lipodepsipeptides
Geudens, Niels; Feher, Kristina; De Vleeschouwer, Matthias et al

Poster (2014, February)

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See detailInteraction of fengycin with stratum corneum mimicking model membranes: a calorimetry study
Eeman, Marc; Oloffson, Gerd; Sparr, Emma et al

in Colloids and Surfaces B : Biointerfaces (2014), In Press

Based on its outstanding antifungal properties, it is reasonable to believe that fengycin might be efficient to topically treat localized dermatomycoses. Since most of the fungi species involved in the ... [more ▼]

Based on its outstanding antifungal properties, it is reasonable to believe that fengycin might be efficient to topically treat localized dermatomycoses. Since most of the fungi species involved in the formation of those mycotic skin diseases colonize primarily the stratum corneum (SC), studying the interaction between fengycin and SC-mimicking lipid membranes is a primary step to determine the potential of fengycin to overcome the physical barrier of the skin. In this respect, multilamellar lipid vesicles (MLVs), with a lipid composition mimicking that of the SC, were prepared and characterized by differential scanning calorimetry (DSC). The critical micelle concentration (CMC) of fengycin was also assessed under skin conditions and found to be 1.2 ± 0.1 μM. The molecular interactions of fengycin with SC-mimicking MLVs were investigated by both DSC and isothermal titration calorimetry (ITC). Results showed that the interactions were considerably affected by changes in lipid phase behaviour. At 40 °C and below, fengycin induced exothermic changes in the lipid structures suggesting that less-ordered lipid domains became more-ordered in presence of fengycin. At 60 °C, clearly endothermic interaction enthalpies were observed, which could arise from the “melting” of remaining solid domains enriched in high melting lipids that without fengycin melt at higher temperatures. [less ▲]

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See detailSpectroscopic analysis of the remorin-lipid interactions at the moleculaer level
Nasir, Mehmet Nail ULg; Perraki, Artemis; Mongrand, Sébastien et al

Poster (2014)

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See detailMulti-scale modeling of mycosubtilin lipopeptides at the air/water interface: structure and optical second harmonic generation
Loison, Claire; Nasir, Mehmet Nail ULg; Benichou, Emmanuel et al

in Physical Chemistry Chemical Physics [=PCCP] (2014), 16

Monolayers of the lipopeptide mycosubtilin are studied at the air/water interface. Their structure is investigated using molecular dynamics simulations. All-atom models suggest that the lipopeptide is ... [more ▼]

Monolayers of the lipopeptide mycosubtilin are studied at the air/water interface. Their structure is investigated using molecular dynamics simulations. All-atom models suggest that the lipopeptide is flexible and aggregates at the interface. To achieve simulation times of several microseconds, a coarse-grained (CG) model based on the MARTINI force field was also used. These CG simulations describe the formation of half-micelles at the interface for surface densities up to 1 lipopeptide per nm2. In these aggregates, the tyrosine side chain orientation is found to be constrained: on average, its main axis, as defined along the C–OH bond, aligns along the interface normal and points towards the air side. The origin of the optical second harmonic generation (SHG) from mycosubtilin monolayers at the air/water interface is also investigated. The molecular hyperpolarizability of the lipopeptide is obtained from quantum chemistry calculations. The tyrosine side chain contribution to the hyperpolarizability is found to be dominant. The orientation distribution of tyrosine, associated with a dominant hyperpolarizability component along the C–OH bond of the tyrosine, yields a ratio of the susceptibility elements χ(2)ZZZ/χ(2)ZXX consistent with the experimental measurements recently reported by M. N. Nasir et al. [Phys. Chem. Chem. Phys., 2013, 15, 19919]. [less ▲]

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See detailReorientation of the helix of the tryptophan-rich gp41W peptide from HIV-1 at interfaces
Matar, Gladys; Benichou, Emmanuel; Nasir, Mehmet Nail ULg et al

in Journal of Chemical Physics (2013), 139

The glycoprotein gp41 from the Human Immunodeficiency Virus type 1 (HIV-1) has an amino acid sequence enriched in tryptophan residues, the so-called gp41W peptide (i.e., KWASLWNWFNITNWLWYIK) and plays a ... [more ▼]

The glycoprotein gp41 from the Human Immunodeficiency Virus type 1 (HIV-1) has an amino acid sequence enriched in tryptophan residues, the so-called gp41W peptide (i.e., KWASLWNWFNITNWLWYIK) and plays a crucial role in HIV-1 host cell infection. Using the coupling of Second Harmonic Generation targeting the tryptophan residues with lateral surface tension measurements, we investigate the interaction of gp41W with a neat air/water and a lipid/water interfaces. At the air/water interface, gp41W presents a well-defined orientation and this orientation is strongly modified at the lipid/water interface, depending on the surface pressure. These results show that this strategy is well suited to monitor tryptophan containing α-helices orientation at lipid/water interfaces. [less ▲]

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See detailLIPID INTERACTION PROPERTIES OF NOVEL RHAMNOLIPIDS
Nasir, Mehmet Nail ULg; Crowet, Jean-Marc ULg; Lins, Laurence ULg et al

Conference (2013, November)

Biosurfactants which are surface active molecules produced by micro-organisms present a wide structural diversity (glycolipids, lipoaminoacids, lipopeptides, polymers,...) and numerous advantages compared ... [more ▼]

Biosurfactants which are surface active molecules produced by micro-organisms present a wide structural diversity (glycolipids, lipoaminoacids, lipopeptides, polymers,...) and numerous advantages compared to their chemically synthesized counterparts. Among glycolipids, rhamnolipids which are secondary metabolites produced mainly by strains of Pseudomonas aeruginosa, have drawn particular attention as they have several interesting biological properties such as antimicrobial, antiphytoviral, zoosporicidal and plant defense elicitor activities [1-3]. It is generally recognized that these activities must be linked to the interaction of these molecules with constituents of biological membranes [4] but the detailed mechanism is far from being fully understood. In our laboratory, new rhamnolipids with various chain lengths and with or without a terminal carboxylic acid function were obtained via the development of a synthesis procedure consisting of two biocatalyzed steps involving naringinase and lipase [5]. The objective of this work was to investigate their interaction with model membranes in relation with their structure in order to give insight about the mechanism of their biological action. A range of complementary experimental and modelling methods was used to analyze their interaction with membrane models. Results reveal differential interaction with lipids according to the structure of the rhamnolipid. The nature of the lipid is also a key parameter for the ınteractions. [less ▲]

Detailed reference viewed: 56 (18 ULg)