GATES Initiative : PhD pathways in partnership with UGA

Finn Sombrutzki conducts his research in collaboration with the Institut de Biologie Structurale (IBS – CEA/CNRS/UGA), focusing on the early steps leading to amyloid formation, specifically exploring protein and hydration water dynamics.

Following a biotechnology diploma (BTA Ausbildung) in Neumünster, Germany, and a Service Civique in Grenoble, Finn pursued a Chemistry degree at the University of Freiburg, and later completed a Master’s in Structural Biology in Grenoble—paving the way for his current doctoral work launched in November 2023.

In biological systems, homogenous protein solutions can spontaneously demix through liquid–liquid phase separation, generating a protein-rich dense phase and a protein-depleted dilute phase. Intrinsically disordered proteins frequently participate in liquid–liquid phase separation (LLPS). Finn’s project centers on the tau protein, which is expressed in neurons and forms insoluble fibrils—a hallmark of Alzheimer’s disease.

His objective is to study the changes in protein and hydration water dynamics during LLPS, focusing on nanosecond timescales and Ångström-length scales. To probe these fast molecular motions, he will use neutrons from ILL’s high-flux reactor to measure energy exchanges between the tau protein and its surrounding water molecules. These insights will allow him to quantify hydrogen atom diffusion and gain a deeper understanding of the biophysical mechanisms behind amyloidogenesis.

Experiments will be carried out on ILL’s IN16B backscattering spectrometer, for which Finn has been allocated beamtime in the reactor’s second cycle this year. His project is co-supervised by Yann Fichou (European Institute of Chemistry and Biology), Giorgio Schirò and Martin Weik (IBS) as well as Tilo Seydel (ILL).

Théodore Arnaud thesis is co-directed by the ILL and the Centre de Recherches sur les Macromolécules Végétales (CERMAV – CNRS/UGA), and focuses on using neutron diffraction to unravel how pathogens interact with human glycolipids.

A graduate in biology from ENS Paris-Saclay with a dual master’s degree in Biology and Health, Théodore developed a strong interest in microbiology and biochemistry through a range of research placements. These experiences inspired him to pursue a PhD at the crossroads of structural biology, microbiology, and biochemistry.

Many pathogens recognize carbohydrate molecules during the initial stages of infection, often via virulence factors or toxins that target host-cell glycolipids. Gaining a detailed structural understanding of these interactions can pave the way for designing new inhibitors as alternatives to antibiotic treatments. Launched in October 2023, Théodore’s research aims to analyse the binding of bacterial proteins to human sugars using neutron crystallography—a technique that reveals unique details about hydrogen bonding and protonation states.

His work involves the production and purification of deuterated recombinant proteins and sugars through synthetic biology. Suitable crystals have already been obtained, and structural analyses are being conducted using ILL’s state-of-the-art instruments, LADI and DALI.

Théodore is jointly supervised by Anne Imberty, research director at CERMAV, and Matthew Blakeley, instrument scientist and LADI/DALI beamline responsible at the ILL.