Themed collection Natural and artificial metalloenzymes

This paper overviews the final remarks lecture delivered (by K. D. K.) at the end of this bioinorganic chemistry Faraday Discussion, held online for a worldwide audience from January 31 – February 3, 2022.

An efficient electrochemical method for the selective oxidation of alcohols to their corresponding aldehydes/ketones using a biomimetic iron complex, [(bTAML)Fe^III–OH₂]⁻, as the redox mediator in an undivided electrochemical cell with inexpensive carbon and nickel electrodes using water as an oxygen source is reported.

Density functional theory calculations reveal subtle differences between the mechanism of asymmetric transfer hydrogenation of a ketone by half-sandwich Ru(II) and Os(II) arene catalysts with 5 chiral centres with formate as the hydride source.

A Cu(III) intermediate, A^DBPD, effects novel dehalogenation–hydroxylations of exogenous phenolates; it is best formulated as containing 2 phenolates/Cu₂O₂ core.

Two-dimensional ¹³C HYSCORE spectroscopy, in conjunction with QM/MM and DFT, indicates that methanol binds to the Mn₄Ca-oxo cluster in the S₂ state of D1-N87A photosystem II from Synechocystis sp. PCC 6803.

The unique spectroscopic features of metalloenzymes reflect novel geometric and electronic structures imposed by the protein activating the metal sites for efficient biological function.

X-ray absorption spectroelectrochemistry has the potential to provide insight into enzyme mechanisms. However, protein loading on the electrode surface must be optimized and controls in place to differentiate electrochemically driven changes from beam induced damage.

In this paper, we discuss for the first time that copper vanadate (CuV₂O₆) can not only release NO from S-nitrosothiols but can also control ROS levels by functionally mimicking the antioxidant enzyme glutathione peroxidase at physiological pH..

The performance for H₂ production of a bio-inspired CoFe complex was evaluated and compared to its two efficient FeFe and NiFe analogs. Unexpectedly, it did not show any electrocatalytic activity for H₂ production.

We here demonstrate the interest of incorporating substrate diffusion tools in multiscale modelling of artificial metalloenzymes.

Ab initio CASSCF/NEVPT2 calculations were utilised to offer a multiconfigurational perspective on the high-valent metal–oxo species that exist beyond the oxo-wall.

The iron(IV)-oxido-chlorido complex shown has an S = 1 ground state and is the most reactive nonheme iron oxidant. It is shown that the reactivity relates to the energy of the d_x²−y² orbital and therefore to the ligand field strength of the co-ligand.

Iron porphyrins are synthesized by systematically introducing electron withdrawing groups (EWGs) on pyrroles to evaluate the relationship between rate (k) and overpotential (η).

A synthetic mimic for the putative Fe^IV₂O₂ diamond core of sMMOH-Q.

Mechanistic pathways in sensitised lanthanide luminescence.

Using a combination of CW-EPR X-band spectroscopy and DFT calculations, we show that the active site of a chitin-active AA10 lytic polysaccharide monooxygenase can exist in three different protonation states, representing the ionisation of the coordinating groups.

A new artificial metalloenzyme for the transfer hydrogenation reaction of cyclic imines following a supramolecular anchoring strategy of the Ir-based metal catalyst to a natural alcohol hydrogenase supported by computational modelling from the start.

We have found that CYP152A1 possesses catalase activity, which competes with the hydroxylation of long-chain fatty acids, the oxidation of non-native substrates, and haem degradation.

A detailed kinetics and mechanistic study on the reactivity of nonheme iron(iv)-oxo complexes for the dehalogenation reactions with halophenols reveals that the reaction proceeds via initial H-atom abstraction. The product distribution indicates that more than one reaction pathway is plausible.

Copper(I) complexes with macrocyclic thioether ligands reacted with ozone to form labile “dioxygen adduct” complexes.