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This paper explores a method for determining the solution structure of a solvent-exposed polypeptide segment (the L3 loop), which is next to the active site of the penicillin-degrading enzyme IMP-1. Tagging three different sites on the protein with paramagnetic metal ions allowed positioning of the L3 loop with atomic resolution. It was found that the method was more robust when omitting data obtained with different metal ions if obtained with the same tag at the same tagging site.

We present the ongoing work of a large, community initiative to establish standards for the processing of nonuniformly sampled NMR experiments. The NUScon software, contest, and archive of spectral evaluation data provide a comprehensive platform for addressing the most challenging questions related to NUS experiments. We will run annual contests and generate a database of results, which will empower us in guiding the NUS community towards a set of best practices.

We demonstrate the formation of spin noise echoes which occur after the application of opposite sign magnetic field gradients to an ensemble of spins. Exploiting this phenomenon, diffusion and spin relaxation parameters in concentrated samples can be determined from nuclear spin noise spectra acquired after tailored sequences of pulsed magnetic field gradients. These methods do not require any excitation from a radio frequency source.

To increase experimental efficiency, information can be encoded in parallel by taking advantage of highly resolved NMR spectra. Here we demonstrate parallel encoding of optimal diffusion parameters by selectively using a resonance for each molecule in the sample. This yields a factor of n decrease in experimental time since n experiments can be encoded into a single measurement. This principle can be extended to additional experimental parameters as a means to further improve measurement time.

The signals that are attainable in conventional NMR are tiny, and consequentially, NMR is often slow and insensitive. The intensity may be increased by hyperpolarization, provided that the spectral quality is essentially preserved. We have recently reported a potentially powerful hyperpolarization scheme, named bullet-DNP (dynamic nuclear polarization). Here, we report a 10-fold improvement in resolution for that method, which may enable new applications in metabolomics and drug discovery.

Fluorine NMR was used to study the interaction between a proline-rich peptide and a SH3 domain using 4S- and 4R-fluorinated prolines whose potential as NMR probes has not been exploited yet. We present a comprehensive study addressing several aspects to be considered when using these residues as NMR probes, including relaxation and dynamics. We show that their conformational bias may be used to modulate the kinetics of protein binding to proline-rich motifs.

We describe a suite of experiments that exploit field-dependent relaxation measurements of four-spin transitions in methyl groups to characterise chemical exchange processes and which can be used as an alternative or complement to CPMG relaxation dispersion measurements. We show that these four-spin transitions benefit from the methyl TROSY effect and so provide a unique combination of slow intrinsic relaxation and high sensitivity to chemical exchange.

The Biological Magnetic Resonance Data Bank (BMRB) has been used to identify overall trends, for example, the relationship between chemical shift and backbone conformation. The BMRB archive has grown so that statistical outliers are sufficiently numerous to afford insights into unusual or unique structural features in proteins. We analyze amide proton chemical shift outliers to gain insights into the occurrence of hydrogen bonds between an amide NH and the p-pi cloud of aromatic sidechains.

Quantum-rotor-induced polarization, also called the Haupt effect, is a hyperpolarization technique in NMR relying on the coupling of nuclear spin states to rotational quantum states. The classic molecule showing this effect is γ-picoline. One might assume that many other molecules carrying a methyl group might also show this effect. Here we explore, using a heuristic approach, other molecules which appear to be promising candidates.