Publications by authors named "J Defaye"

Introduction: The production of highly vigorous seeds with high longevity is an important lever to increase crop production efficiency, but its acquisition during seed maturation is strongly influenced by the growth environment.

Methods: An association rule learning approach discovered MtABI4, a known longevity regulator, as a gene with transcript levels associated with the environmentally-induced change in longevity. To understand the environmental sensitivity of transcription, Yeast One-Hybrid identified a class I BASIC PENTACYSTEINE (MtBPC1) transcription factor as a putative upstream regulator.

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A collection of homologous monodisperse facial amphiphiles consisting of an α-, β- or γ-cyclodextrin (α, β or γCD) platform exposing a multivalent display of cationic groups at the primary rim and bearing hexanoyl chains at the secondary hydroxyls have been prepared to assess the influence of the cyclooligosaccharide core size in their ability to complex, compact and protect pDNA and in the efficiency of the resulting nanocondensates (CDplexes) to deliver DNA into cells and promote transfection in the presence of serum. All the polycationic amphiphilic CDs (paCDs) were able to self-assemble in the presence of the plasmid and produce transfectious nanoparticles at nitrogen/phosphorous ratios ≥5. CDplexes obtained from βCD derivatives generally exhibited higher transfection capabilities, which can be ascribed to their ability to form inclusion complexes with cholesterol, thereby enhancing biological membrane permeability.

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Selective chemical functionalization of cyclodextrins (CDs) is a readily amenable methodology to produce amphiphilic macromolecules endowed with modulable self-organizing capabilities. Herein, the synthesis of well-defined amphiphilic CD derivatives, with a "skirt-type" architecture, that incorporate long-chain fatty esters at the secondary hydroxyl rim and a variety of chemical functionalities (e. g.

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Fully homogeneous facial amphiphiles consisting in a cyclodextrin (CD) platform onto which a polycationic cluster and a multi-tail hydrophobic moiety have been installed (polycationic amphiphilic CDs; paCDs) self-organized in the presence of plasmid DNA to form nanometric complexes (CDplexes) which exhibit broad-range transfection capabilities. We hypothesized that biorecognizable moieties located at the hydrophilic rim in the CD scaffold would be exposed at the surface of the corresponding nanoparticles after DNA-promoted aggregation, endowing the system with molecular recognition abilities towards cell receptors. This concept has been demonstrated by developing an efficient synthetic strategy for the preparation of multivalent polycationic glyco-amphiphilic CDs (pGaCDs).

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Article Synopsis
  • The study uses molecular dynamics simulations to analyze how p-toluenesulfonyl chloride (TsCl) interacts with β-cyclodextrin (βCD) in both a vacuum and a water environment, focusing on energy pathways for insertion.
  • Results indicate that TsCl prefers to enter the βCD cavity with its sulfonyl chloride group oriented toward the primary hydroxyls, with notable energy minima detected in vacuum correlating with findings from NMR spectroscopy.
  • When water is introduced, these energy minima merge, and the calculated association constant for TsCl and βCD aligns closely with NMR results, allowing for a method to activate βCD using a temporary Cu(2+) chelate in a single step process.
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