On average a human being has about 160 species of bacteria in the gut. The objectives of our project are to define the structural parameters that drive bacterial adhesion and balance the composition of the microbiome to maintain a healthy gut. The receptors of bacterial adhesins are dynamically glycosylated proteins or lipids involved in poorly defined signalling pathways that serve both host and bacterium in a fragile symbiotic relationship.
The identification of mucosal glycan receptors for adhesins is examplary on shotgun glycan arrays and artificial designed glycan-modified interfaces. The picked-up glycosylated receptors are structurally characterized using mass spectrometry and nuclear magnetic resonance in the laboratory skilled for glycobiology. Their energy of interaction is calculated in quantum mechanical interaction models and validated in surface plasmon resonance and calorimetric measurements. Crystallography and different light scattering techniques in solution (SAXS, DLS, MALLS) of the adhesin-receptor complexes form the central work horse to unite the approaches and detail the selecting factors of specificity and geometry in multivalence-induced aggregative bacterial adhesion in the competitive and collaborative world of the microbiome in mucosae. This research helps the design of agonistic and antagonistic drugs favoring gut health.