Allostery in ion channels controls activation coupled inactivation and partly controls mean open time. Solid state NMR experiments on full length wild type channel in proteoliposomes provide evidence for evacuation of ions from the selectivity filter during inactivation and strong coupling between opening and ion affinity. Furthermore, a number of site specific mutants altered in their...
G protein-coupled receptors (GPCRs) are physiologically important transmembrane signaling proteins that elicit intracellular responses upon binding of ligands on the extracellular site. Breakthroughs in crystallography have provided a wealth of static GPCR structures ranging from ligand-bound inactive receptors to fully active receptors in complex with intracellular binding partners such as...
The behaviour of side chains is fundamental to the biology and pathology of proteins. They play essential roles in processes as diverse as folding, catalysis, binding and allosteric regulation, and it is clear that in many cases their function is as much linked to their dynamic behaviour as their structure. Despite their significance, methods probing the behaviour of side chains are limited,...
NMR studies of large proteins, over 100 kDa, in solution are technically challenging and thereby of considerable interest in the NMR field. This is primarily due to slowing of molecular tumbling in solution as molecular mass increases. Typical 1H-13C or 1H-15N correlation spectra using 13C- or 15N uniformly labeled proteins show severe line-broadening and signal overlap. It is well known that...
Lanthanide ions accelerate nuclear spin relaxation by two primary mechanisms: dipolar and Curie. Both are commonly assumed to depend on the length of the lanthanide-nucleus vector, but not on its direction. In this communication, we demonstrate experimentally and verify theoretically that this is wrong – careful proton relaxation data analysis in a series of isostructural lanthanide complexes...
The glucocorticoid receptor (GR) binds steroid hormones, leading to structural rearrangements that drive DNA binding, recruitment of coregulator proteins, and ultimately gene regulation. Different receptor-ligand complexes have distinct interactions with coregulators, resulting in differential gene regulation. The allosteric mechanism within the ligand-binding domain (LBD) has remained...
Rheo NMR has been applied to investigate the effect of external shear on the aggregation and on the chain dynamics of polymers. A Couette cell with the polymer melt or solution in the gap is applied. To get further insight, oscillating rotation in addition to continuous rotation has been applied.
An in-house built rheo NMR system using a servo motor, avoiding any vibrations has been used on a...
With the advent of site-specific isotope labeling and deuteration, the study of local dynamics in biological macromolecules, has reached levels of unprecedented accuracy. There are, however, many cases in e.g. soft materials science, where such strategies are not feasible. While classical carbon-13-based solid-state NMR techniques are often possible, they nevertheless suffer from low...
Higher magnetic fields lead to higher sensitivity and higher resolution. Reaching higher fields is key to study biomolecular systems of increasing complexity. Yet, higher fields are not optimal for all applications of NMR, neither for all nuclei. For instance, the chemical shift anisotropies of carbon-13 nuclei in many chemical entities, or that of fluorine-19 lead to transverse relaxation...