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The development of synthetic molecules able to transport ions through lipid bilayer membranes is of growing interest in the field of supramolecular chemistry. The balance of anions and cations has an important role in the biology of all living organisms. This thesis will focus on the development of copper(I) transporters, the methodologies developed to study them, and their biological applications. The first part of this thesis is focused on the development of copper(I) transmembrane transporters and the methodology required for their study. These transporters were developed for a potential therapeutic application, with the idea that synthetic copper(I) transporters could replace dysfunctional copper(I) transport proteins, which are responsible for distributing copper(I) within cells. Dysfunction of these proteins is the cause of Wilson and Menkes diseases.Calix4arene functionalised with two imidazole groups can strongly bind copper(I) through a linear coordination motif. This ability and their high lipophilicity made them good candidates to transport copper(I) through bilayer membranes. For that, a new assay was developed using liposomes as model systems for membranes, in which a phenanthroline based copper(I) sensitive dye is encapsulated. The changes in fluorescence as monitored by spectroscopy allowed for the observation of copper(I) transport. Most of these results are reported in the publication: “Transmembrane transport of copper(I) by imidazole-functionalised calix[4]arenes” N. Renier, O. Reinaud, I. Jabin, and H. Valkenier. Chem. Commun. 2020, 56, 8206-8209. The improvement and limitations of the transport assay are also described. In the second part, the development of a deliverable copper(I) transporter is described along with the biological effects of the compound on various biological systems. A new transporter was synthesised and shown to be able to reach liposomes membrane when added from an organic solution or from other liposomes, which was not th, Doctorat en Sciences de l'ingénieur et technologie, info:eu-repo/semantics/nonPublished

The essential cellular functions of the mitochondrion require the exchange of a wide variety of molecules across its two membranes, which is carried out by different membrane proteins.The Voltage-Dependent Anion Channel (VDAC) located in the mitochondrial outer membrane (MOM) is responsible for the passage of various ions and small molecules to and from the intermembrane space. It is also involved in the regulation of cellular processes through its interactions with lipids or other proteins.At the MOM level, we studied the transport, through VDAC, of small inorganic ions and of thiamine pyrophosphate (TPP), an essential cofactor. Using different simulation methods such as Brownian dynamics (BD), All-Atom (AA) molecular dynamics (MD) and Coarse-Grained (CG) MD, we investigated the effect of two factors on the regulation of VDAC ion selectivity: ionic strength and membrane lipid composition. All simulation types show that VDAC becomes less selective towards anions with increasing salt concentration. The simulations further suggest that the selectivity mechanism occurs due to the filtering of some basic residues that point into the pore lumen. Furthermore, MD simulations show that the lipid composition of the membrane modulates the distribution of ions inside VDAC. In a comparison of POPE versus POPC bilayer, this regulation occurs through the more persistent interactions of some acidic residues located on both edges of the β-barrel with POPE head groups which, in turn, alters the electrostatic potential in the lumen which consequently affects the pore selectivity. CG MD simulations show that this mechanism also occurs in a mixed POPE/POPC bilayer by an enrichment of POPE on VDAC surface.In order to simulate the transport of the TPP, force field parameters have been developed and validated. Simulations of the translocation of TPP through VDAC show analogies with the mechanism used by other previously studied metabolites, in particular with ATP. At the mitochondrial inn, Doctorat en Sciences, info:eu-repo/semantics/nonPublished

Hybrid free-standing biomimetic materials are developed by integrating the VDAC36 ß-barrel protein into robust and flexible three-layered polymer nanomembranes. The first and third layers are prepared by spin-coating a mixture of poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA). PVA nanofeatures are transformed into controlled nanoperforations by solvent-etching. The two nanoperforated PLA layers are separated by an electroactive layer, which is successfully electropolymerized by introducing a conducting sacrificial substrate under the first PLA nanosheet. Finally, the nanomaterial is consolidated by immobilizing the VDAC36 protein, active as an ion channel, into the nanoperforations of the upper layer. The integration of the protein causes a significant reduction of the material resistance, which decreases from 21.9 to 3.9 kO cm2. Electrochemical impedance spectroscopy studies using inorganic ions and molecular metabolites (i.e.L-lysine and ATP) not only reveal that the hybrid films behave as electrochemical supercapacitors but also indicate the most appropriate conditions to obtain selective responses against molecular ions as a function of their charge. The combination of polymers and proteins is promising for the development of new devices for engineering, biotechnological and biomedical applications.Hybrid free-standing biomimetic materials are developed by integrating the VDAC36 ß-barrel protein into robust and flexible three-layered polymer nanomembranes. The first and third layers are prepared by spin-coating a mixture of poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA). PVA nanofeatures are transformed into controlled nanoperforations by solvent-etching. The two nanoperforated PLA layers are separated by an electroactive layer, which is successfully electropolymerized by introducing a conducting sacrificial substrate under the first PLA nanosheet. Finally, the nanomaterial is consolidated by immobilizing the VDAC36 protein, active as an ion channe, Peer Reviewed, Postprint (author's final draft)