Increasing attention is being focused on the role of protein structural dynamics in crucial cellular signaling pathways and modulating structural dynamics is becoming an important avenue of exploitation for the discovery of new therapeutic compounds. However, there remains a serious paucity of experimental techniques that permit one to obtain relevant data related to structural dynamics on appropriate timescales. New approaches are needed to both elucidate and measure physical properties directly related to structural dynamics. Various physical chemical methods have been used to probe the structural dynamics, but each technique has it own limitations. So the search for new methods, complementary to existing ones, is still underway. In this proposal, our primary objective is to develop THz/far infrared absorption spectroscopy for the ligand binding events. Ligand binding will influence the underlying collective motions in this frequency range, which can be captured by far-IR experiments and interpreted through molecular simulations and structural analysis. Previously, we combined far-IR and molecular dynamics simulations to study the response of a PDZ domain to the binding of a small peptide ligand to elucidate the mechanism of allostery. We showed that exploitable information concerning changes in low frequency collective motions could be obtained even for proteins where there is no substantial conformational change upon ligand binding. This integrated approach allowed us to quantify a mechanism of allostery in a PDZ domain. In this project, we aim to enlarge the field of application and characterize the allosteric behavior in nuclear receptor (NR) proteins, which constitute a superfamily of proteins that function as DNA-binding, ligand dependent transcription factors. Being a larger, more complex protein than the one used in our preliminary study, they are implicated in the transcriptional cascade underlying many physiological phenomena making them one of the major signal transduction paradigms in metazoans. Indeed, evidence suggests that there exist multiple mechanisms exploiting structural dynamics and allostery that implicate ligand, DNA, co-activator and co-repressor binding, as well as post-translational modifications. Central to these mechanisms is the ligand binding domain (LBD), which acts as an allosteric hub, transmitting binding events to other protein interfaces and domains. We will focus on Peroxisome Proliferator-Activated Receptor gamma (PPAR-gamma) and its heterodimeric partner, RXRa, a nuclear receptor complex that is a particularly important target for development of therapeutic compounds for multiple diseases, including diabetes and cancer. Our project will begin with a study of the LDBs in both wild-type and mutant forms. We will characterize the effects of ligands, including agonists, antagonists and co-regulator peptides by far infrared absorption spectroscopy, molecular dynamics simulations and biophysical/structural characterization and interpret the results in the context of allosteric effects. Following the study of the LDB, we will expand our study towards heterodimer structures. A second objective is to gain molecular insight into the mechanisms of selective modulation of NRs activity by small-molecule ligands and ultimately make the link with their pharmacological profile. The consortium is comprised of members complementary in their expertise coming from fields of physical and computational chemistry, biophysics and structural biology. Through the fundamental research to be carried out by this high-level multi-disciplinary unit, a novel approach for the study of ligand binding in biomolecular systems will emerge. This, we believe, makes it a completely original methodological approach that we plan to further develop in the context of this call.

Post-translational modifications dramatically expand the chemical repertoire of ribosome-synthesised polypeptides and enable otherwise inaccessible molecular functionalities. Some of them are remarkably conserved. For example, the universal ribosomal protein uS11, which in humans is involved in incurable ribosomopathies, undergoes isoaspartylation (i.e. conversion of an asparagine or an aspartate residue into a ß-connected isoaspartate) in most living organisms. Spontaneous isoaspartylation, which kinks the polypeptide chain, is extremely damaging for most proteins and is associated with severe human diseases. However, in uS11 this modification is functionally essential and strictly required for the assembly of the small ribosomal subunit in nearly all species, from E. coli to humans. We identified two families of ancient, deeply conserved enzymes that are most likely responsible for the installation of this unusual modification in bacterial- and eukaryotic/archaeal-type ribosomes. In this ambitious, interdisciplinary project, bringing together experts in bacterial, mitochondrial, eukaryotic RNA biology and ribosome assembly on the one side and those in peptide chemistry and proteomics of post-translational modifications on the other, we will use a wide palette of chemical, biochemical, mass spectrometry, structural, genetic, and physiological approaches to understand the how and why of this unique modification. More specifically, we will undertake a detailed and comprehensive analysis of uS11 isoaspartylation across the tree of life (including model bacteria, archaea, yeast, human cells, protists, and plants). We will decipher the detailed enzymatic mechanisms and idiosyncrasies of this modification. Finally, we will rationalise the essential role of uS11 isoaspartylation in central biological functions of universal significance, including ribosome assembly, protein synthesis, respiration, growth and proliferation.

The aim of the CDeePL project is to design new biocompatible Porous Liquids (PLs) able of selectively dissolving target molecules. These innovative materials will be obtained by dispersing Cyclodextrin-Metal-Organic Frameworks (CD-MOFs) in Deep Eutectic Solvents (DESs). The use of biocompatible starting materials (CD-MOFs and DESs) will enlarge the range of applications of PLs, as smart delivery platforms, within the food, pharmaceutical and cosmetic sectors. The originality of our approach lies on the never explored combination of the recognized properties of CDs and MOFs, as hosts, with DESs, as liquid media, to form fluids with permanent porosity. These new hybrid materials will be fully characterized by combining structural techniques, analytical investigations, thermodynamics and computational studies. The ability of these novel PLs to act as delivery platforms will be investigated by evaluating their biocompatibility and stability. They will be then evaluated for their ability to solubilize poorly aqueous soluble (i.e. quercetin, resveratrol, ibuprofen) or volatile (i.e. trans-anethole, sevoflurane) molecules used as model bioactive compounds. The release profile of the solubilized compounds will be further examined. The molecular mechanisms involved in the selective solvation of the bioactive compounds will be also assessed theoretically by state-of-the-art molecular simulations. The findings of this project will encourage the use of the obtained tailorable hybrid materials, toward specific applications, notably those that require biocompatibility.

BattAllox aims at targeting multiple electron transfer and tuneable redox properties for enhanced energy storage systems. Using bioinspired design principles and molecular engineering, this project focuses on interfacing redox-active isoalloxazine and alloxazine units with coordination chemistry to deliver highly tuneable and versatile redox systems. Redox behaviour at the molecular and higher levels will be studied on small-molecule organic units, organometallic complexes and Coordination Polymers. These redox species will be the basis of a new class of robust multi-electron transfer materials, for electrode materials, for example, and will be incorporated in redox-flow batteries. This multi-scale and multidisciplinary approach bring together molecular design, electrochemical studies, coordination networks and redox-flow batteries.

Organic Light-Emitting Diodes (OLEDs) are revolutionizing display market technology. Also, they are appealing for other applications, including lightweight and flexible devices operating at high brightness under low power. Yet, there are still key-challenges that need be tackled, e.g. efficient and robust, rare metal-free materials and suitable device engineering. The project BOOSTOLED aims at purely organic, thermally-activated delayed fluorescence-active (TADF) materials for efficient deep-red to NIR OLEDs for biomedical applications. The project challenges innovative donor-acceptor (D-A) systems that combine narrow bandgap, high photoluminescence quantum yield and balanced charge transport. BOOSTOLED will explore different material engineering strategies, including intra- and through-space TADF materials. Energy-efficient flexible/stretchable tandem OLEDs will be developed that can simultaneously achieve high external quantum efficiency >60%, brightness >10^5cd/m2 and long lifetime.