Design of Chemical Shift-Switching¹⁹F Magnetic Resonance Imaging Probe for Specific Detection of Human Monoamine Oxidase A

Abstract

Monoamine oxidase (MAO) A is a flavoenzyme that catalyzes the oxidation of biologically important monoamines and is thought to be associated with psychiatric disorders. Here, we report a strategy for rationally designing a (19)F magnetic resonance imaging probe for the specific detection of human MAO-A (hMAO-A) activity. Our designed (19)F probe was oxidized expeditiously by hMAO-A to produce 2-fluoro-4-nitrophenol via a spontaneous β-elimination mechanism. Concomitant with the structural change of the probe to the product, the (19)F chemical shift changed by 4.2 ppm, which was enough to visualize the probe and enzymatic product separately. Importantly, our probe achieved excellent discrimination of hMAO-A from its isoform hMAO-B.

Ultrahigh 19F Loaded Cu1.75S Nanoprobes for Simultaneous 19F Magnetic Resonance Imaging and Photothermal Therapy

“…1,2 19 F MRI is anticipated to be a promising alternative to conventional 1 H MRI because of its high sensitivity (0.83 relative to 1 H), 3–6 negligible background signals, 7 and cost-effectiveness, which allows direct detection of 19 F-labeled probes such as cells 6,8 and drug capsules 9 for unambiguous identification and quantification, unlike typical metal-based contrast agents. 10,11 In order to obtain highly sensitive 19 F MRI probes for their practical implications, it is important to increase the number of fluorine atoms in the MRI probes.…”

Simple and inexpensive incorporation of 19F-Tryptophan for protein NMR spectroscopy

“…2 Amino acid analogues containing fluorine are powerful tools for protein NMR spectroscopy. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] The 19 F nucleus (spin 1/2, 100% isotopic abundance) is highly sensitive and does not occur naturally in biomacromolecules, leading to facile spectral interpretation. Fluorine-containing proteins have found numerous applications including the study of high molecular weight proteins, 12,17 protein folding, 6,[9][10][11]14 domain swapping, 19 and protein-ligand binding.…”

New frontiers and developing applications in 19F NMR

“…Recent reports have shown evolution of both color pigment or fluorescence and 19 F NMR signal [109, 184, 185]. New β-gal (β-galactosidase) reporters simultaneously show 19 F chemical shift and 1 H contrast effects [186, 187].…”