Preprints  

Nanometer distance measurements between spin labels by pulse EPR techniques yield structural information on the molecular level. Here, backed by experimental data, we derive a description for the total signal of the single frequency technique for refocusing dipolar couplings (SIFTER) showing how the different spin-spin interactions give rise to dipolar signal and background – the latter has thus far been unknown.

Dynamic nuclear polarization requires a wave guide that connects the cold (1–10 K) sample space to the outside. To reduce the heating of the sample, the wave guide is produced from steel which has low thermal conductivity but attenuates the micro waves. Therefore, the inside of the wave guide should be plated with silver to reduce the electrical losses. We show a new simple way to electroplate such wave guides with a thin silver layer and show that this improves the experimental performance.

Could the gesture of an ancient artist applying a paint layer be reconstructed using EPR analysis? In the case of an inorganic pigment widely used in antiquity, Egyptian blue, where the anisotropy of the Cu2+ EPR signal reflects the symmetry of the pigment crystallites, we have shown that the orientation distribution of the grains, as revealed by simulation of EPR spectra, is indeed influenced by the nature of the gesture.

Providing evidence that proteins are dynamical molecules is a major contribution of solution NMR to structural biology. But the classical experiments to measure dynamics can only be applied to small proteins. This is regretful, because larger proteins often display conformational changes in which dynamics plays a functional role. We show here that dynamic information can be extracted from HSQC NMR spectra using a computational approach. Such spectra are widely available also for larger proteins.

We show here that information about protein molecular dynamics can be directly extracted out of a single NMR spectrum. Understanding protein dynamics is essential to understanding its function, energetics and biology. We hope that this contribution helps bring this insight to a much broader application field and audience community than previously possible.

The demonstration of the Finite Pulse Radio Frequency Driven Recoupling experiment was firstly published over the past 20 years. Since it has become one of the used experiments. In this article we consider that experiment using other theoretical and simulated approaches with respect to the previous works. These approaches help us to understand more clearly the influence of each part of that experiment and to see how exactly the spin system is evaluated during it.

We recently added 2D NMR spectroscopy to the well-established techniques able to obtain information on the process of unfolding using resonances of residues in the hydrophobic core of a protein. We asked whether a detailed analysis of the individual stability curves could provide additional site-specific information. By monitoring both cold and heat denaturation of individual residues we convincingly demonstrate that the two unfolding processes are intrinsically different.

Nowadays, almost all MRI technique used in clinical applications are based on a Fourier transformation of the raw data. Alternative non-Fourier magnetic resonance imaging techniques can offer some advantages under certain conditions. SPatio-temporal ENcoding (SPEN) is a non-Fourier method that usually employs frequency-swept radio frequency pulses and can give good images in inhomogeneous magnetic fields. In this work we show how one can improve this technique by using quadratic gradients.