Research
Research
Main areas of research focus are enzymes and proteins involved in neurological disorders on the one hand and bacterial virulence and persistence pathways on the other hand. The insights we obtain are subsequently being used to devise new strategies to fight human disease.
To unravel these enzyme mechanisms at an atomic level and to understand the way they operate in the context of biological pathways, we use an integrated approach of structural biology methods (cryo-EM, X-ray crystallography, SAXS), protein engineering, biochemistry/biophysics and detailed steady-state and pre-steady-state kinetics. Conformation-specific Nanobodies are used throughout as versatile tools to stabilize flexible proteins or subunits from large protein complexes and/or to modulate their activity.
Unravelling the structure, function and (mis)regulation of Parkinson’s disease-associated proteins
Brain disorders, including Alzheimer’s disease, Parkinson’s disease, epilepsy and stroke, are one of the greatest health challenges today. Parkinson’s disease (PD) is the second most common neurodegenerative disorder and affects millions of people worldwide. Nevertheless, a curative treatment is still lacking. Mutations in more than 20 genes cause familial PD. Many of the corresponding proteins seem to play roles in protein homeostasis and the endo-lysosomal pathway. To gain a deeper insight in these processes and their mis-regulation by PD mutations, an important line of research in our lab evolves around the elucidation of the structure, mechanism and regulation of a subset of these proteins. In the past few years this research has already led to important breakthroughs in our understanding of Synaptojanin 1 (Synj1) and Leucine-Rich Repeat Kinase 2 (LRRK2). Apart from these PD-linked proteins we previously also worked on a number of proteins involved in other neurological disorders, such as TBC1D24-associated epilepsy/DOORS syndrome.
Allosteric targeting of PD-associated enzymes using conformation-specific Nanobodies
Pathogenic mutations in PD-associated proteins/enzymes typically lead to a decreased conformational stability or loss/gain of enzymatic activity. Conformation-specific Nanobodies (single domain fragments of camelid heavy-chain antibodies) form exquisite tools to stabilize and modulate the activity of these affected enzymes. As an important proof-of-principle for this approach, we recently succeeded in developing and characterizing Nanobodies that can either increase the GTPase activity or inhibit the kinase activity of LRRK2, thereby restoring the effect of the most common PD mutations.
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An atomic resolution view on the pathways leading to bacterial persistence and virulence
Due to the development of resistance mechanisms to antibiotics, bacterial infections are becoming more life-threatening every year. It is expected that by 2050, 10 million people per year will die from infections by antibiotic-resistant bacteria. Besides resistance, bacterial persistence offers a means to avoid clearance of infections. Persisters are formed by phenotypic switching to an antibiotic-tolerant state, rendering a small subset of cells within an isogenic population capable of surviving antibiotic treatment, which can subsequently also lead to the development of resistance.
To gain more insight into the mechanisms of persistence, we want to unravel the associated molecular pathways down to atomic resolution. One master regulator of persistence is the multi-domain GTPase Obg. We are therefore studying the structure and function of this protein and its protein-protein interactions within the persistence pathways. Another multi-domain GTPase under study is MnmE. MnmE forms a very intriguing protein-protein complex with its partner in crime, MnmG. The MnmEG complex catalyzes a tRNA modification reaction and was identified as an important determinant of bacterial virulence. Moreover, mutations in the human orthologs of MnmE and MnmG (GTPBP3 and Mto1) are associated with severe mitochondrial diseases.
