Protein and peptide interactions are characterized in the liquid state by multidimensional NMR spectroscopy experiments, which can take hours to record. We show that starting from hyperpolarized HDO, two-dimensional (2D) proton correlation maps of a peptide, either free in solution or interacting with liposomes, can be acquired in less than 60 s. In standard 2D NMR spectroscopy without hyperpolarization, the acquisition time required for similar spectral correlations is on the order of hours. This hyperpolarized experiment enables the identification of amino acids featuring solvent-interacting hydrogens and provides fast spectroscopic analysis of peptide conformers. Sensitivityenhanced 2D proton correlation spectroscopy is a useful and straightforward tool for biochemistry and structural biology, as it does not recur to nitrogen-15 or carbon-13 isotope enrichment.

The isomerisation of 6-phosphogluconolactones and their hydrolyses into 6-phosphogluconic acid form a non enzymatic side cycle of the pentose-phosphate pathway (PPP) in cells. Dissolution dynamic nuclear polarisation can be used for determining the kinetic rates of the involved transformations in real time. It is found that the hydrolysis of both lactones is significantly slower than the isomerisation process, thereby shedding new light onto this subtle chemical process.

We present novel means to hyperpolarize deuterium nuclei in CD groups at cryogenic temperatures. The method is based on cross-polarization from H toC and does not require any radio-frequency fields applied to the deuterium nuclei. After rapid dissolution, a new class of long-lived spin states can be detected indirectly by C NMR in solution. These long-lived states result from a sextet-triplet imbalance (STI) that involves the two equivalent deuterons with spin I = 1. An STI has similar properties as a triplet-singlet imbalance that can occur in systems with two equivalent I = 12 spins. Although the lifetimes T are shorter than T(C), they can exceed the life-time T(D) of deuterium Zeeman magnetization by a factor of more than 20.