Drug Screening Boosted by Hyperpolarized Long‐Lived States in NMR

Abstract

Transverse and longitudinal relaxation times (T1ρ and T1) have been widely exploited in NMR to probe the binding of ligands and putative drugs to target proteins. We have shown recently that long-lived states (LLS) can be more sensitive to ligand binding. LLS can be excited if the ligand comprises at least two coupled spins. Herein we broaden the scope of ligand screening by LLS to arbitrary ligands by covalent attachment of a functional group, which comprises a pair of coupled protons that are isolated from neighboring magnetic nuclei. The resulting functionalized ligands have longitudinal relaxation times T1(1H) that are sufficiently long to allow the powerful combination of LLS with dissolution dynamic nuclear polarization (D-DNP). Hyperpolarized weak “spy ligands” can be displaced by high-affinity competitors. Hyperpolarized LLS allow one to decrease both protein and ligand concentrations to micromolar levels and to significantly increase sample throughput.

Optimizing dissolution dynamic nuclear polarization

“…High contrast-to-noise images can be obtained in a fraction of seconds [31]. In our laboratory, 1 H d-DNP was combined with long-lived proton states to enhanced both the sensitivity and contrast in drug screening experiments [32], and hyperpolarized water was used for protein-ligand interaction studies in combination with the so called WaterLOGSY technique [33].…”

Dynamic Nuclear Polarization of Long-Lived Nuclear Spin States in Methyl Groups

“…Potential applications of the LLS concept include drug screening, molecular imaging and reaction monitoring. [7][8][9] LLS have been used as a carrier of hyperpolarisation. [10][11][12][13][14][15] Molecular scaffolds have been designed to minimise the relaxation rates of singlet order, with reported lifetimes of over an hour.…”

Rapid-melt Dynamic Nuclear Polarization

“…Other applications include biomolecular NMR [63,64], biological assays [65,66], detection of reaction intermediates having low concentrations [67], protein folding [68], and drug screening [69]. The use of dissolution DNP in a clinical environment is under development [70].…”