Signal-enhanced real-time magnetic resonance of enzymatic reactions at millitesla fields

Abstract

The phenomenon of nuclear magnetic resonance (NMR) is widely applied in biomedical and biological science to study structures and dynamics of proteins and their reactions. Despite its impact, NMR is...

Characterization of Protocatechuate 4,5-Dioxygenase from Pseudarthrobacter phenanthrenivorans Sphe3 and In Situ Reaction Monitoring in the NMR Tube

“…19 F and 31 P NMR require the presence of the appropriate isotope in the ligands. 13 C NMR requires selectively enrichment in 13 C ligands and/or the use of hyperpolarization methods which require specialized NMR instrumentation [67]. The advantage of the present in situ monitoring approach of an enzymatic reaction by free enzyme in the NMR tube is that the complete characterization can be achieved by the combined use of 1D, 2D, 1 H-1 H, and 1 H- 13 C HSQC and HMBC NMR spectroscopy.…”

Rapidly Signal‐enhanced Metabolites for Atomic Scale Monitoring of Living Cells with Magnetic Resonance

“…Although NMR has found such a wide applicability, it is inherently insensitive. To overcome this challenge, signal‐enhancement or hyperpolarization strategies have been developed, leading to amplifications of over 10,000‐fold of the NMR signal [4–45] . One key application of hyperpolarization is the real‐time detection of metabolic conversion allowing to probe metabolic dysfunction in, for example, cancer [4–8] .…”

“…The most prominent hyperpolarization technique is dissolution DNP (dynamic nuclear polarization), which is, however, only available to a few sites due to its high instrumentation complexity, high costs, and the production of hyperpolarized compounds takes long times (tens of minutes to hours) [4–13] . Para ‐hydrogen‐based techniques promise to be a solution for the fast (seconds) production of hyperpolarized compounds in easy‐to‐use devices that can also be mobile [14–31] . To obtain enhanced and 13 C‐labelled metabolites such as pyruvate, para ‐hydrogen is reacted with an unsaturated metabolite precursor, the polarization is subsequently transferred to a 13 C atom of interest in the metabolite, followed by rapid conversion of the precursor into the desired metabolite [21] .…”

Lanthanide DO3A-Complexes Bearing Peptide Substrates: The Effect of Peptidic Side Chains on Metal Coordination and Relaxivity

“…Such amplification is particularly important in Magnetic Resonance Imaging (MRI), which suffers from intrinsic low sensitivity. Many pathologies are characterized by abnormal enzymatic activities, and the last two decades have seen very important chemistry efforts towards the development of chemical probes allowing for molecular imaging detection of a large variety of enzymes [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Given its high resolution, unlimited tissue penetration and non-invasiveness, MRI is particularly interesting for in vivo monitoring of enzymatic activities.…”

“…A great number of enzyme-responsive T 1 and CEST probes have been proposed in the last two decades [ 2 , 3 , 4 , 14 , 15 ]. Some very recent studies report on hyperpolarized probes dedicated to enzymatic detection [ 6 , 8 ]. Gadolinium-free probes are also explored [ 7 ].…”