Enzyme Control Over Ferric Iron Magnetostructural Properties. (2nd December 2021)

• Record Type: Journal Article
• Authors: Wang, Huan; Cleary, Michael B.; Lewis, Luke C.; Bacon, Jeffrey W.; Caravan, Peter; Shafaat, Hannah S.; Gale, Eric M.
• Is Part Of: Angewandte Chemie. Volume 134:Number 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-02
• Subjects: Bioresponsive -- Imaging -- Iron -- Magnetic resonance -- Sensors; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202114019
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Fe 3+ complexes in aqueous solution can exist as discrete mononuclear species or multinuclear magnetically coupled species. Stimuli‐driven change to Fe 3+ speciation represents a powerful mechanistic basis for magnetic resonance sensor technology, but ligand design strategies to exert precision control of aqueous Fe 3+ magnetostructural properties are entirely underexplored. In pursuit of this objective, we rationally designed a ligand to strongly favor a dinuclear μ‐oxo‐bridged and antiferromagnetically coupled complex, but which undergoes carboxylesterase mediated transformation to a mononuclear high‐spin Fe 3+ chelate resulting in substantial T1 ‐relaxivity increase. The data communicated demonstrate proof of concept for a novel and effective strategy to exert biochemical control over aqueous Fe 3+ magnetic, structural, and relaxometric properties. Abstract : We introduce a first‐in‐class stimuli responsive Fe 3+ complex that is switched between discrete antiferromagnetically coupled and high‐spin paramagnetic species through the action of a carboxylesterase enzyme. We also demonstrate how enzyme‐mediated switching of Fe 3+ magnetic properties offers a mechanistic foundation for new bioresponsive magnetic resonance sensor technology.