RESEARCH >> Theme: ion transport across lipid bilayers

ION TRANSPORT ACROSS LIPID BILAYERS

 

A new research project developed in the EMNS Lab deals with ion transport across lipid membranes using supramolecular carriers.

#1 Anion transport across lipid membranes by supramolecular receptors

 

Channel-forming membrane proteins are responsible for the transport of charged species through cell membranes. Dysfunction in ion transport is the cause of numerous diseases, of which cystic fibrosis is probably the most well-known. It is possible to compensate for the defect or under-expressed membrane protein channel activity by using synthetic molecules which can carry anions through the lipid bilayer. Our goal is to study the thermodynamics, kinetics, and structural parameters of anion carriers inside lipid bilayer membranes in order to highlight the key parameters governing the efficiency of organic receptors as transporters. We use both state-of-the-art physical organic chemistry and biophysical methods, such as advanced NMR techniques, microcalorimetry and fluorescence spectroscopy, to obtain an extensive understanding of the transport phenomenon and propose new rules for the design of the next generation of anion transporters.

 

 

Heads: Dr Hennie Valkenier & Prof. Kristin Bartik

Co-workers/researchers: Ir Glenn Grauwels, Mr Nathan Renier

Collaborations: Prof. Tony Davis (University of Bristol), Prof. Ivan Jabin (ULB),
Prof. Vladimir Sindelar (Masaryk University, Brno)

Funding: FNRS (Post-doctoral and PhD fellowships)

Publications:

Repositioning Chloride Transmembrane Transporters: Transport of Organic Ion Pairs

Grauwels G., Valkenier H., Davis A. P., Jabin I., & Bartik K., Angewandte Chemie International Ed. 58, 6921-6925 (2019).

 

Fluorinated Bambusurils as Highly Effective and Selective Transmembrane Cl/HCO3 Antiporters

Valkenier H., Akrawi O., Jurček P., Sleziaková K., Lízal T., Bartik K. and Šindelář V., Chem 5(2), 429-444 (2019) - Download post-print.

 

 

#2 transport OF ORGANOPHOSPHATES ACROSS MEMBRANES (ORGANITRA)

 

Membranes function as impermeable barriers for ionic and hydrophilic species which can only cross the membrane with the aid of dedicated membrane proteins. For biotechnological and biophysical applications, the development of anion carriers that can bind an anion and transport it across the lipid bilayer could be of great relevance.

In this project, synthetic anion receptors will be developed to bind biologically relevant organic phosphorylated compounds, like nucleotides. Dynamic combinatorial chemistry will be used to synthesise and identify efficient receptors. These will then be used to transport the organophosphates across membranes. Liposomes will be used as model systems to study the transport process.

 

 

 

Head: Dr Hennie Valkenier

Co-workers/researchers: Dr Luis Martinez Crespo, Mr Lau Halgreeen, Mr Anurag Singh, Mr Alessio Cataldo

Funding: This project has received funding from the FNRS (H.V. is a Chercheuse Qualifiée of the Fonds de la Recherche Scientifique–FNRS) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 802727).

 

 

#3 TRANSMEMBRANE TRANSPORT OF COPPER(I) CATIONS BY SYNTHETIC RECEPTORS

 

This project addresses transmembrane transport of copper(I) cations. Different proteins transport copper(I) ions across the membranes of organelles and cells, while problems with these proteins is the cause of various diseases.

The aim of this project is to develop and study synthetic molecules which are able to selectively bind and transport copper(I) ions through lipid bilayer membranes. These molecules are integrated in the membrane and behave as mobile carriers by diffusing across the bilayer. Such molecules may have potential for the treatment of diseases related to disruption of copper homeostasis.

 

 

 

Head: Dr Hennie Valkenier

Co-worker/researcher: Mr Nathan Renier

Collaboration: Prof. Ivan Jabin (ULB, Laboratory of Organic Chemistry)

Funding: FNRS (FRIA PhD fellowship)

 

Publication:

Transmembrane transport of copper(I) by imidazole-functionalised calix[4]arenes

Renier N., Reinaud O., Jabin I. & Valkenier H., Chemical Communication (2020 - Accepted). Download pre-print.

 

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