Controlled Uptake of an Iridium Complex inside Engineered apo‐Ferritin Nanocages: Study of Structure and Catalysis

• Published in: Angewandte Chemie International Edition Vol. 61; no. 13; pp. e202116623 - n/a
• Main Authors: Taher, Mohd, Maity, Basudev, Nakane, Taiki, Abe, Satoshi, Ueno, Takafumi, Mazumdar, Shyamalava
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 21-03-2022
• Edition: International ed. in English
• Subjects: Alcohols; Artificial Enzyme Catalysis; Catalysis; Enantiomers; Ferritin; Ferritins - chemistry; Ferritins - genetics; Hybrid Bio-nanocage; Hydrogenation; IrCp; Iridium; Iridium - chemistry; Iridium compounds; Molecular docking; Molecular Docking Simulation; Mutation; Stereoisomerism; Substrates; Transfer Hydrogenation; Transfer Hydrogenation; Artificial Enzyme Catalysis; IrCp; Hybrid Bio-nanocage; Ferritin
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202116623

The effect of the mutation at the core of the ferritin nanocage (apo‐rHLFr) on the uptake of IrCp* has been investigated by structural and spectroscopic methods. Site‐specific mutations of two polar residues viz., Asp38 and Arg52 were investigated. The uptake of IrCp* was increased by about 1.5‐fold on mutation of Arg52 by His compared to the wild‐type variant, while mutation of Asp38 by His had no effect on the uptake. All the variants of the Ir‐embedded ferritin cages remained as stable as the wild‐type analogue. These hybrid bio‐nanocages of ferritin were found to efficiently catalyze transfer hydrogenation of various substituted acetophenones forming the corresponding chiral alcohols with up to 88 % conversion and 70 % enantioselectivity. An electron‐withdrawing substituent on the reactant enhanced the Turnover frequency of the reaction. Molecular docking analyses suggested that the substrate binds in different orientations at the active site in different mutants of the nanocage.
A stable hybrid bio‐nanocage with selective immobilization of an iridium complex inside the self‐assembly protein, ferritin has been developed. These hybrid bio‐catalysts reduce substituted acetophenones into the corresponding chiral alcohols with high enantioselectivity.