Reversible Enzymatic Switching of the Oxidation State of a Eu III/II Complex Controls Relaxivity
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide We show that europium trisbipyridyl cryptate exhibits an electrochemically reversible Eu III/II redox couple at −360 mV vs the standard hydrogen electrode (SHE) and is susceptible to reduction or oxidation by a range of redox enzymes or biological small molecule redox agents. Modulation of the europium oxidation state can be used to achieve dramatic changes in the T 1 relaxation time of bulk water in solutions containing these complexes: in the reduced form, the complex exhibits high relaxivity (3.08 mM –1 s –1 at 499.9 MHz) comparable with that of commercial MRI contrast media, while the oxidized form has negligible relaxivity, illustrating the scope for application in imaging reducing environments in biological systems.
DOI: 10.1021/jacs.5c13447
Authors: Euan T. Sarson, Saul M. Cooper, Adam C. Sedgwick, Amy-Grace Berger, Sophie A. Twigger, Ester M. Hammond, Kylie A. Vincent, Stephen Faulkner
Institution: University of Oxford
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: EPSRC Centre for Doctoral Training in Inorganic Chemistry for Future Manufacturing (OxICFM), Chemical biology tools for investigating the chemistry of cellular REDOX stress, NextGen Structural Biology under Electrochemical Control: Filling in Missing Intermediates in Metalloenzyme Catalytic Cycles, Biocatalysis for Sustainable Chemistry – Understanding Oxidation/Reduction of Small Molecules by Redox Metalloenzymes via a Suite of Steady State and Transient Infrared Electrochemical Methods
OpenAlex ID: W4415251052