Recent  

A novel cell-free protein synthesis system called eCells produces amino acids based on specific isotopes using low-cost precursors. The system selectively labels methyl groups; i.e valine and leucine with high efficiency. eCells achieve high levels of ¹³C incorporation and deuteration in protein preparations, making them suitable for NMR experiments of large protein complexes. It is easy to prepare and can be scaled up in volume, making it a promising tool for protein production and NMR studies.

Since its discovery 65 years ago, the solid-state DNP effect has been rationalized in terms of mixing of the Zeeman energy levels. Before becoming aware of this explanation, Erb, Motchane and Uebersfeld proposed a dynamical equation to make sense of their experiments. Here we provide a formal justification of their phenomenological equation. The result is a different way of thinking about the solid-state effect with novel implications about the effect in liquids.

We show that the field profile of the solid effect in liquids is rich in dynamical information, including about time scales of molecular diffusion. We develop a general theoretical framework for extracting this information through quantitative fits to the experimental data. Unusual peaks in the enhancement field profile, which resemble thermal mixing but are not related to it, are demonstrated to arise in liquids under some conditions. These additionally restrict the dynamical parameters.