ERC FUNDED PROJECTS

The emergence of life is one of the most fascinating and yet largely unsolved questions in the natural sciences, and thus a significant challenge for scientists from many disciplines. There is growing evidence that ribonucleic acid (RNA) polymers, which are capable of genetic information storage and self-catalysis, were involved in the early forms of life. But despite recent progress, RNA synthesis without biological machineries is very challenging. The current project aims at understanding how to synthesize RNA in abiotic conditions. I will solve problems associated with three critical aspects of RNA formation that I will rationalize at a molecular level: (i) accumulation of precursors, (ii) formation of a chemical bond between RNA monomers, and (iii) tolerance for alternative backbone sugars or linkages. Because I will study problems ranging from the formation of chemical bonds up to the stability of large biopolymers, I propose an original computational multi-scale approach combining techniques that range from quantum calculations to large-scale all-atom simulations, employed together with efficient enhanced-sampling algorithms, forcefield improvement, cutting-edge analysis methods and model development. My objectives are the following: 1 • To explain why the poorly-understood thermally-driven process of thermophoresis can contribute to the accumulation of dilute precursors. 2 • To understand why linking RNA monomers with phosphoester bonds is so difficult, to understand the molecular mechanism of possible catalysts and to suggest key improvements. 3 • To rationalize the molecular basis for RNA tolerance for alternative backbone sugars or linkages that have probably been incorporated in abiotic conditions. This unique in-silico laboratory setup should significantly impact our comprehension of life’s origin by overcoming major obstacles to RNA abiotic formation, and in addition will reveal significant orthogonal outcomes for (bio)technological applications.

1 497 031 €

Start date: 2018-02-01, End date: 2023-01-31

Microporous materials are an important class of solid; the two main members of this family are zeolites and metal-organic frameworks (MOFs). Zeolites are industrial solids whose applications range from catalysis, through ion exchange and adsorption technologies to medicine. MOFs are some of the most exciting new materials to have been developed over the last two decades, and they are just beginning to be applied commercially. Over recent years the applicant’s group has developed new synthetic strategies to prepare microporous materials, called the Assembly-Disassembly-Organisation-Reassembly (ADOR) process. In significant preliminary work the ADOR process has shown to be an extremely important new synthetic methodology that differs fundamentally from traditional solvothermal methods. In this project I will look to overturn the conventional thinking in materials science by developing methodologies that can target both zeolites and MOF materials that are difficult to prepare using traditional methods – the so-called ‘unfeasible’ materials. The importance of such a new methodology is that it will open up routes to materials that have different properties (both chemical and topological) to those we currently have. Since zeolites and MOFs have so many actual and potential uses, the preparation of materials with different properties has a high chance of leading to new technologies in the medium/long term. To complete the major objective I will look to complete four closely linked activities covering the development of design strategies for zeolites and MOFs (activities 1 & 2), mechanistic studies to understand the process at the molecular level using in situ characterisation techniques (activity 3) and an exploration of potential applied science for the prepared materials (activity 4).

2 489 220 €

Start date: 2018-10-01, End date: 2023-09-30

Applied electrochemistry plays a key role in many technologies, such as batteries, fuel cells, supercapacitors or solar cells. It is therefore at the core of many research programs all over the world. Yet, fundamental electrochemical investigations remain scarce. In particular, electrochemistry is among the fields for which the gap between theory and experiment is the largest. From the computational point of view, there is no molecular dynamics (MD) software devoted to the simulation of electrochemical systems while other fields such as biochemistry (GROMACS) or material science (LAMMPS) have dedicated tools. This is due to the difficulty of accounting for complex effects arising from (i) the degree of metallicity of the electrode (i.e. from semimetals to perfect conductors), (ii) the mutual polarization occurring at the electrode/electrolyte interface and (iii) the redox reactivity through explicit electron transfers. Current understanding therefore relies on standard theories that derive from an inaccurate molecular-scale picture. My objective is to fill this gap by introducing a whole set of new methods for simulating electrochemical systems. They will be provided to the computational electrochemistry community as a cutting-edge MD software adapted to supercomputers. First applications will aim at the discovery of new electrolytes for energy storage. Here I will focus on (1) ‘‘water-in-salts’’ to understand why these revolutionary liquids enable much higher voltage than conventional solutions (2) redox reactions inside a nanoporous electrode to support the development of future capacitive energy storage devices. These selected applications are timely and rely on collaborations with leading experimental partners. The results are expected to shed an unprecedented light on the importance of polarization effects on the structure and the reactivity of electrode/electrolyte interfaces, establishing MD as a prominent tool for solving complex electrochemistry problems.

1 588 769 €

Start date: 2018-04-01, End date: 2023-03-31

The description of high pressure phases or polymorphism of molecular solids represents a significant scientific challenge both for experiment and theory. Theoretical methods that are currently used struggle to describe the tiny energy differences between different phases. It is the aim of this project to develop a scheme that would allow accurate and reliable predictions of the binding energies of molecular solids and of the energy differences between different phases. To reach the required accuracy, we will combine the coupled cluster approach, widely used for reference quality calculations for molecules, with the random phase approximation (RPA) within periodic boundary conditions. As I have recently shown, RPA-based approaches are already some of the most accurate and practically usable methods for the description of extended systems. However, reliability is not only a question of accuracy. Reliable data need to be precise, that is, converged with the numerical parameters so that they are reproducible by other researchers. Reproducibility is already a growing concern in the field. It is likely to become a considerable issue for highly accurate methods as the calculated energies have a stronger dependence on the simulation parameters such as the basis set size. Two main approaches will be explored to assure precision. First, we will develop the so-called asymptotic correction scheme to speed-up the convergence of the correlation energies with the basis set size. Second, we will directly compare the lattice energies from periodic and finite cluster based calculations. Both should yield identical answers, but if and how the agreement can be reached for general system is currently far from being understood for methods such as coupled cluster. Reliable data will allow us to answer some of the open questions regarding the stability of polymorphs and high pressure phases, such as the possibility of existence of high pressure ionic phases of water and ammonia.

924 375 €

Start date: 2018-01-01, End date: 2022-12-31

It is a basic textbook notion that the plasma membranes of virtually all organisms display an asymmetric lipid distribution between inner and outer leaflets far removed from thermodynamic equilibrium. As a fundamental biological principle, lipid asymmetry has been linked to numerous cellular processes. However, a clear mechanistic justification for the continued existence of lipid asymmetry throughout evolution has yet to be established. We propose here that lipid asymmetry serves as a store of potential energy that is used to fuel energy-intense membrane remodelling and signalling events for instance during membrane fusion and fission. This implies that rapid, local changes of trans-membrane lipid distribution rather than a continuously maintained out-of-equilibrium situation are crucial for cellular function. Consequently, new methods for quantifying the kinetics of lipid trans-bilayer movement are required, as traditional approaches are mostly suited for analysing quasi-steady-state conditions. Addressing this need, we will develop and employ novel photochemical lipid probes and lipid biosensors to quantify localized trans-bilayer lipid movement. We will use these tools for identifying yet unknown protein components of the lipid asymmetry regulating machinery and analyse their function with regard to membrane dynamics and signalling in cell motility. Focussing on cell motility enables targeted chemical and genetic perturbations while monitoring lipid dynamics on timescales and in membrane structures that are well suited for light microscopy. Ultimately, we aim to reconstitute lipid asymmetry as a driving force for membrane remodelling in vitro. We expect that our work will break new ground in explaining one of the least understood features of the plasma membrane and pave the way for a new, dynamic membrane model. Since the plasma membrane serves as the major signalling hub, this will have impact in almost every area of the life sciences.

1 500 000 €

Start date: 2018-01-01, End date: 2022-12-31

The goal of ATOMICAR is to achieve the ultimate sensitivity limit in heterogeneous catalysis: Quantitative measurement of chemical turnover on a single catalytic nanoparticle. Most heterogeneous catalysis occurs on metal nanoparticle in the size range of 3 nm - 10 nm. Model studies have established that there is often a strong coupling between nanoparticle size & shape - and catalytic activity. The strong structure-activity coupling renders it probable that “super-active” nanoparticles exist. However, since there is no way to measure catalytic activity of less than ca 1 million nanoparticles at a time, any super-activity will always be hidden by “ensemble smearing” since one million nanoparticles of exactly identical size and shape cannot be made. The state-of-the-art in catalysis benchmarking is microfabricated flow reactors with mass-spectrometric detection, but the sensitivity of this approach cannot be incrementally improved by six orders of magnitude. This calls for a new measurement paradigm where the activity of a single nanoparticle can be benchmarked – the ultimate limit for catalytic measurement. A tiny batch reactor is the solution, but there are three key problems: How to seal it; how to track catalytic turnover inside it; and how to see the nanoparticle inside it? Graphene solves all three problems: A microfabricated cavity with a thin SixNy bottom window, a single catalytic nanoparticle inside, and a graphene seal forms a gas tight batch reactor since graphene has zero gas permeability. Catalysis is then tracked as an internal pressure change via the stress & deflection of the graphene seal. Crucially, the electron-transparency of graphene and SixNy enables subsequent transmission electron microscope access with atomic resolution so that active nanoparticles can be studied in full detail. ATOMICAR will re-define the experimental limits of catalyst benchmarking and lift the field of basic catalysis research into the single-nanoparticle age.

1 496 000 €

Start date: 2018-02-01, End date: 2023-01-31

One of the ultimate goals in cell biology is to understand how cells determine their shape. In bacteria, the cell wall and the actin-like (MreB) cytoskeleton are major determinants of cell shape. As a hallmark of microbial life, the external cell wall is the most conspicuous macromolecule expanding in concert with cell growth and one of the most prominent targets for antibiotics. Despite decades of study, the mechanism of cell wall morphogenesis remains poorly understood. In rod-shaped bacteria, actin-like MreB proteins assemble into disconnected membrane-associated structures (patches) that move processively around the cell periphery and are thought to control shape by spatiotemporally organizing macromolecular machineries that effect sidewall elongation. However, the ultrastructure of MreB assemblies and the mechanistic details underlying their morphogenetic function remain to be elucidated. The aim of this project is to combine ground-breaking light microscopy and spectroscopy techniques with cutting-edge genetic, biochemical and systems biology approaches available in the model rod-shaped bacterium Bacillus subtilis to elucidate how MreB and cell wall biosynthetic enzymes collectively act to build a cell. Within this context, new features of MreB assemblies will be determined in vivo and in vitro, and a “toolbox” of approaches to determine the modes of action of antibiotics targeting cell wall processes will be developed. Parameters measured by the different approaches will be used to refine a mathematical model aiming to quantitatively describe the features of bacterial cell wall growth. The long-term goals of BActin are to understand general principles of bacterial cell morphogenesis and to provide mechanistic templates and new reporters for the screening of novel antibiotics.

1 902 195 €

Start date: 2019-02-01, End date: 2024-01-31

Despite that C–H functionalization represents a paradigm shift from the standard logic of organic synthesis, the selective activation of non-functionalized alkanes has puzzled chemists for centuries and is always referred to one of the remaining major challenges in chemical sciences. Alkanes are inert compounds representing the major constituents of natural gas and petroleum. Converting these cheap and widely available hydrocarbon feedstocks into added-value intermediates would tremendously affect the field of chemistry. For long saturated hydrocarbons, one must distinguish between non-equivalent but chemically very similar alkane substrate C−H bonds, and for functionalization at the terminus position, one must favor activation of the stronger, primary C−H bonds at the expense of weaker and numerous secondary C-H bonds. The goal of this work is to develop a general principle in organic synthesis for the preparation of a wide variety of more complex molecular architectures from saturated hydrocarbons. In our approach, the alkane will first be transformed into an alkene that will subsequently be engaged in a metal-catalyzed hydrometalation/migration sequence. The first step of the sequence, ideally represented by the removal of two hydrogen atoms, will be performed by the use of a mutated strain of Rhodococcus. The position and geometry of the formed double bond has no effect on the second step of the reaction as the metal-catalyzed hydrometalation/migration will isomerize the double bond along the carbon skeleton to selectively produce the primary organometallic species. Trapping the resulting organometallic derivatives with a large variety of electrophiles will provide the desired functionalized alkane. This work will lead to the invention of new, selective and efficient processes for the utilization of simple hydrocarbons and valorize the synthetic potential of raw hydrocarbon feedstock for the environmentally benign production of new compounds and new materials.

2 499 375 €

Start date: 2018-11-01, End date: 2023-10-31

Intercellular communication is critical for multicellularity. It coordinates the activities within individual cells to support the function of an organism as a whole. Plants have developed remarkable cellular machines -the Plasmodesmata (PD) pores- which interconnect every single cell within the plant body, establishing direct membrane and cytoplasmic continuity, a situation unique to plants. PD are indispensable for plant life. They control the flux of molecules between cells and are decisive for development, environmental adaptation and defence signalling. However, how PD integrate signalling to coordinate responses at a multicellular level remains unclear. A striking feature of PD organisation, setting them apart from animal cell junctions, is a strand of endoplasmic reticulum (ER) running through the pore, tethered extremely tight (~10nm) to the plasma membrane (PM) by unidentified “spokes”. To date, the function of ER-PM contacts at PD remains a complete enigma. We don’t know how and why the two organelles come together at PD cellular junctions. I recently proposed that ER-PM tethering is in fact central to PD function. In this project I will investigate the question of how integrated cellular responses benefit from organelle cross-talk at PD. The project integrates proteomic/bioinformatic approaches, biophysical/modelling methods and ultra-high resolution 3D imaging into molecular cell biology of plant cell-to-cell communication and will, for the first time, directly address the mechanism and function of ER-PM contacts at PD. We will pursue three complementary objectives to attain our goal: 1) Identify the mechanisms of PD membrane-tethering at the molecular level 2) Elucidate the dynamics and 3D architecture of ER-PM contact sites at PD 3) Uncover the function of ER-PM apposition for plant intercellular communication. Overall, the project will pioneer a radically new perspective on PD-mediated cell-to-cell communication, a fundamental aspect of plant biology

1 999 840 €

Start date: 2018-06-01, End date: 2023-05-31