Cyclic and lipid metabolite-inspired detergents for the extraction and stabilization of membrane proteins – Cytergents

Nowadays, membrane proteins represent the majority of current therapeutic targets. Detergents are generally used to extract them from the membrane and keep them soluble for downstream in vitro studies and characterization. However, many proteins denature when extracted, losing rapidly their native structures and activities. Cytergents is a basic research project that aims at exploring new approaches in the design of detergents, at understanding more precisely the detergents / lipids / protein interactions that determine extraction and stabilization, and at evaluating their ability to maintain membrane proteins in a functional form. The originality of these detergents lies (1) in the insertion of a cyclohexyl unit in a variable position within the hydrophobic part or (2) in the insertion of a cyclopentane backbone mimicking membrane lipid metabolites. This synthesis methodology is based on a chemistry seldom used in the field of detergents. We will use a glycoside as a polar part in order to ensure good solubility of the detergent in water. The self-assembly properties of these amphiphilic molecules will be studied by various biophysical methods. We will determine the critical micellar concentration i.e. the threshold concentration of self-assembly into micelles, a crucial parameter to ensure correct protein extraction. We will also determine, the size, the shape and the composition of the micelles, properties that can affect both stability and function of the extracted proteins. Finally, the biochemical validation will be carried out on several types of proteins of fundamental and pharmaceutical interest and will make it possible to evaluate (1) the solubilizing potency, that is the potency of detergents to destabilize membranes and to extract membrane proteins, and (2) the stabilizing potency, that is the ability to keep proteins stable, functional and soluble. Cytergents is based on a complementary consortium that associates two teams of chemists, a team of biochemists and a biotechnology company specialized in therapeutic membrane targets. At the end of the project, the results obtained could be rapidly industrialized by integrating these new detergents into the internal projects of the partner company and by ensuring their marketing and worldwide distribution.