Laboratoire de Biologie Physico-Chimique des Protéines Membranaires

The LBPC-PM is organized into 4 topics (no teams) :

→ Theme 1. Bruno Miroux, Karine Moncoq, Daniel Picot and Francesca Zito, Manuela Zoonens :
Energy coupling and supramolecular organization of respiratory complexes

Structural bioenergetics : It combines i) a methodological approach to the crystallography of membrane proteins and ii) a study of electron transfer chain in photosynthesis and respiration, centred on the linchpin joint complex: the complex Rieske/cytochrome b. It includes studies of the possible source of ROS production and the organization of the different complexes of the electron transfer chain in supercomplexes.

Mitochondrial bioenergetics: it focuses on the structure-function relationships of mitochondrial uncoupling proteins and other carriers in connection with mitochondrial metabolism. The role of fatty acid in transport mechanisms will be more specifically investigated.

→ Theme 2. Valérie Biou and Laurent Catoire :
Molecular signalling of GPCRs

We use NMR and X-ray crystallography combined with other biophysical methods to study the various actors involved in signal transduction by G protein-coupled receptors: ligands, receptors and intracellular effectors. We are presently focussing on lipid signalling (leukotriene receptors) and the Hedgehog signalling pathway. Obtaining various proteins necessarily implies an important activity of molecular biology and biochemistry. Downstream biophysical studies also include methodological development.

→ Theme 3. Philippe Delepelaire and Dror Warschawski :
Transport and membrane dynamics in bacteria

Through various methods, ranging from microbial physiology to solid state NMR, we study model systems recognition phenomena and substrate transport across the bacterial envelope, and related signaling pathways.

Within this framework, we study the transport of porphyrins across the bacterial envelope, and the bacterial response to mechanical stress. Since solid-state NMR allows the study of membrane proteins inserted into membranes, we favor the study of samples either in model lipid membranes, or directly in native bacterial membranes.

→ Theme 4, transversal. Fabrice Giusti, Bruno Miroux, Jean-Luc Popot, Dror Warschawski, Francesca Zito and Manuela Zoonens :
A toolbox for the chemistry of membrane proteins

This theme contains methodological developments necessary to the other three themes :
(1) Production of membrane proteins : approaches to bacterial molecular genetics and chemistry of surfactants are being developed for membrane protein production in vivo and in vitro with particular attention to strategies for isotopic labeling.

(2) Chemical ligands and surfactants : this module includes :

a) the synthesis and validation of amphipols functionalized so-called second generation (deuteration, biotin, polyhistidine, imidazole, oligonucleotides, different fluorescent labels...) for stabilization and purification and vectorization of membrane proteins

b) the synthesis of photoactivatable ligands and substrates for structural and functional studies