Biological function results from time-dependent interactions between biomolecules. NMR spectroscopy is the only experimental method, which yields both structural and dynamical information on biomolecules at atomic resolution with minimal invasiveness and at close to natural conditions. However, it is limited in the molecular size and sensitivity. In the last years we have combined NMR, cryo-EM, single-molecule FRET and other biophysical techniques to derive mechanistic insights at the atomic level into the function and interactions of a number of disease-relevant protein systems. In the next years we want to further develop and conclude several of these projects, which address (1) G protein-coupled receptors (GPCRs), (2) Abelson kinase, (3) c-di-GMP binding proteins, and (4) NMR technology.
Subproject (1) addresses the further dynamical characterization by NMR and other techniques of the function of the beta1-adrenergic receptor (b1AR), which is one of the main targets of beta-blockers, as well as the characterization of functional complexes by cryo-EM and NMR of the human chemokine receptor CCR5, which is also the coreceptor for HIV.
Subproject (2) addresses the further dynamical characterization by single-molecule FRET and NMR of Abelson kinase (Abl), which is a large multi-domain protein and important leukemia drug target. We have now established labeling with fluorophore pairs at arbitrary sites by using unnatural amino acid technology. We want to use this development to study the dynamical behavior of single Abl molecules within (cancer) cells by FRET and combine the obtained information with high-resolution NMR.
Subproject (3) addresses the interactions of the bacterial virulence factor cyclic di-guanosine-monophosphate (c-di-GMP). We have determined the NMR structure and dynamics of several complexes of c-di-GMP binding proteins and want to continue to develop a genetically encodable c-di-GMP fluorescence sensor based on our structural data.
Subproject (4) foresees further developments in NMR technology addressing the rapid assignment of large proteins and the improvement of isotope labeling techniques in higher eukaryotes.