Braca

Nature Catalysis, Published online: 03 November 2025; doi:10.1038/s41929-025-01436-0

The creation of artificial metalloenzymes compatible with complex biological settings could enable broad applications. Now a de novo-designed artificial metalloenzyme containing an abiological ruthenium cofactor is reported and optimized for ring-closing metathesis in the cytoplasm of whole cells.

Nature Catalysis, Published online: 03 November 2025; doi:10.1038/s41929-025-01435-1

Radical repositioning to activate remote bonds is underdeveloped in synthetic biocatalysis. Now a photobiocatalytic system couples light-driven single-electron transfer and the relocation of unpaired electrons to activate remote C–C and C–H bonds for enzymatically controlled enantioselective acylation.

Nature Catalysis, Published online: 31 October 2025; doi:10.1038/s41929-025-01434-2

Constructing C(sp3)–C(sp3) bonds using non-prefunctionalized substrates as radical precursors is challenging. Now an ene-reductase and an organophotoredox catalyst work together to enable the enantiodivergent hydroalkylation of electron-deficient C(sp3)–H bonds via radical intermediates generated from carbanions.

Nickel-catalyzed alkene hydroarylation presents a promising alternative to traditional cross-coupling reactions. Currently, the predominant methods rely on reactive aryl sources such as aryl iodides and arylboronic acids. Aryl chlorides, despite being more readily available and cost-effective, are underutilized because of the high dissociation energy of the C(sp²)−Cl bond. To overcome this limitation, we developed a catalytic system that integrates visible light with nickel catalysis. This approach generates photoexcited metal intermediates capable of surmounting the activation barriers associated with aryl chloride activation. The resulting protocol enables efficient hydroarylation of alkenes using aryl chlorides, thereby facilitating the synthesis of structurally diverse 1,1-diaryl alkanes, a crucial structural motif in bioactive molecules. Notably, the incorporation of chiral ligands into the catalytic system allows for enantioselective synthesis, significantly expanding access to enantioenriched 1,1-diaryl alkanes. Comprehensive mechanistic investigations further revealed a unique photocatalytic mechanism, wherein the generation of alkyl radicals and active Ni(I) species serves as the catalytic cycle's pivotal steps. This dual activation strategy not only enhances substrate scope but also establishes a framework for sustainable cross-coupling methodologies.

Nature Biotechnology, Published online: 14 October 2025; doi:10.1038/s41587-025-02840-4

Recent patents relating to directed evolution methods and products.

Publication date: 11 December 2025

Source: Chem, Volume 11, Issue 12

Author(s): Agnieszka Bajer, Venkateswarulu Mangili, Artur R. Stefankiewicz

Nature Catalysis, Published online: 24 October 2025; doi:10.1038/s41929-025-01409-3

Darwinian evolution has shaped life on our planet through natural selection. Here, the authors report on the combination of self-replication, mutation and protometabolism in an out-of-equilibrium abiotic chemical system that can lead to natural selection for protometabolic activity.

An unexpected heme-dependent enzyme, Alp1J, was identified as the catalyst that installs N─N bond in kinamycin biosynthesis. Alp1J forms a stable complex with ferredoxin Alp1I, which is essential for activity. Together they convert l-aspartate and nitrite into a hydrazine intermediate through a four-electron reductive pathway. The discovery establishes a platform for genome mining and synthetic biology aimed at novel N─N-containing therapeutics.

Abstract

A nitrogen–nitrogen (N─N) bond is a core feature of diverse natural products with interesting structural and biological properties. Kinamycin and lomaiviticin, featuring a diazobenzo[b]fluorene core, exhibit exceptional potency as chemotherapeutic agents. However, the N─N bond forming step in their biosynthesis has remained elusive. Through extensive mutagenesis and biochemical studies, we herein report that Alp1J, belonging to a new family of heme-dependent enzymes, catalyzes the N─N bond formation in kinamycin biosynthesis. Interestingly, Alp1J forms a stable complex with its partner ferredoxin Alp1I, which can protect the cofactors and is critical for the N─N bond formation activity. With its partner ferredoxin, Alp1J catalyzes formation of the hydrazine intermediate directly from l-aspartate and nitrite by a pathway involving four-electron reduction. Our findings expand the knowledge of enzymatic N─N bond formation and show the potential for the discovery and development of novel N─N bond containing natural products through genome mining and synthetic biology.

Nature Chemistry, Published online: 21 October 2025; doi:10.1038/s41557-025-01958-x

Azetidine is a four-membered aza-cycle important in medicinal and organic chemistry. This study describes a mechanism of azetidine amino acid biosynthesis from l-isoleucine or l-valine by two non-haem Fe enzymes, PolF and PolE, in the polyoxin antifungal biosynthetic pathway.

Nature Chemistry, Published online: 20 October 2025; doi:10.1038/s41557-025-01970-1

Achieving generality in asymmetric catalysis with highly reactive radicals is a challenge. Now it is shown that a sequential copper-catalysed approach enables the efficient, enantioselective cross-coupling of over 50 diverse radicals, providing unified access to C-, P- and S-chiral products and advancing the asymmetric synthesis of challenging molecular architectures.

Science, Ahead of Print.

Nature, Published online: 15 October 2025; doi:10.1038/s41586-025-09725-1

Deaminative cross-coupling of amines by boryl radical β-scission

Nature Chemistry, Published online: 03 October 2025; doi:10.1038/s41557-025-01962-1

Selective activation of specific C–F bonds in polyfluoroarenes remains a major challenge in organic synthesis. Now, a photoexcited nickel-catalysed cross-electrophile coupling between polyfluoroarenes and aryl chlorides has been developed. This enables highly selective arylation of atypical C–F sites, facilitated by a synergistic lithium salt effect.

This review focuses on the latest research progress of mechanoenzymatic reactions and their green metrics in line with the Principles of Green Chemistry, and also discusses the challenges and prospects.

Abstract

Mechanoenzymology is a green chemistry technology that has emerged in recent years, which can efficiently promote enzymatic hydrolysis reactions through mechanical force under low-solvent conditions. Mechanoenzymatic reactions has the green metrics of reducing solvent usage, minimizing waste generation, potentially improving reaction efficiency, and mild reaction conditions, which conform to the Principles of Green Chemistry. In this review, the focus is on the latest research progress of mechanoenzymatic reactions and the green aspects based on the Principles of Green Chemistry. The challenges and prospects of mechanoenzymology are discussed to further promote its development and application.

In the framework of developing artificial metalloenzyme (ArM) prodrug therapies, two main factors need to be considered; the cancer targeting capabilities of the ArM biocatalyst and the bioorthogonal prodrug activation mechanism. In this study, both these aspects were investigated to develop an example of an anticancer ArM prodrug strategy. To address targeting, the concept of multivalent lectin-directed artificial metalloenzymes was established using a Halotag-PduU-ACG lectin fusion protein (HtPA) functionalized with a gold catalyst. Acting through multivalent binding of hexameric lectin complexes (caused by PduU oligomerization), selective binding to sialic acid-rich cancer cells was proven. To address prodrug activation, the propargylbenzoxime (PBO) group was developed to undergo gold-catalyzed hydroamination, followed by spontaneous N–O bond cleavage to release carbonyl functional groups under mild and physiological conditions. Further adaptation of the PBO group was also explored so that carbonyl release could elicit the synthesis of indole-containing molecules. HtPA-based artificial metalloenzymes were then subsequently applied in cell assays for the activation of a PBO-based prodrug to highlight this alternative approach of an ArM prodrug therapy.

Nature, Published online: 01 October 2025; doi:10.1038/s41586-025-09519-5

A two-phase machine-learning-based tool making use of high-throughput experimentation is introduced to examine the connections between chemical and protein sequence space and predict productive biocatalytic reactions among substrate and enzyme pairs.

De novo designed proteins offer a malleable platform for the development of stereoselective transformations not found in biochemistry. Here, we report the de novo design and directed evolution of helical bundle protein catalysts for enantioselective germylation through Ge-H insertion, a transformation not previously achieved by enzymatic catalysis. Comparative computational analysis revealed that, relative to Si-H insertion, the Ge-H insertion reaction proceeds through an earlier and more flexible transition state, introducing distinct challenges for stereocontrol. Using a fully de novo designed truncated four-helix bundle scaffold as the starting point, directed evolution afforded a quadruple mutant that catalyzes Ge-H insertion with high efficiency, enantioselectivity, and broad substrate scope. Molecular dynamics simulations indicated that beneficial mutations introduced from directed evolution enhanced active-site preorganization and modulated local back-bone flexibility, contributing to improved transition-state complementarity with fine-tuned binding pocket size and more stable cofactor positioning regulated by hydrogen bonding interactions. These findings showcase the excellent potential for de novo proteins to achieve stereoselective transformations previously unknown to biocatalysts and underscore the importance of active-site remodeling of de novo protein scaffolds via directed evolution in achieving selective catalysis involving flexible transition states. Table of Contents artwork O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=87 SRC="FIGDIR/small/679279v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@162187forg.highwire.dtl.DTLVardef@13665a4org.highwire.dtl.DTLVardef@4afff1org.highwire.dtl.DTLVardef@1e92f92_HPS_FORMAT_FIGEXP M_FIG C_FIG

Nature Chemistry, Published online: 30 September 2025; doi:10.1038/s41557-025-01949-y

Azetidine is a pharmacophore present in drug-related molecules. Here the authors unveil a two-metalloenzyme cascade leading to the azetidine-containing polyoximic acid, in which PolE functions as an Fe2+/pterin-dependent l-isoleucine desaturase, while PolF is a haem-oxygenase-like diiron oxidase, orchestrating the sequential desaturation and cyclization. These findings expand our knowledge of metalloenzymes.

Nature Chemistry, Published online: 25 September 2025; doi:10.1038/s41557-025-01937-2

Visible-light-driven pyridoxal radical biocatalysis offers a promising approach for developing stereoselective intermolecular radical reactions that have no known precedent in biology or chemistry. Now, building on the engineering of pyridoxal-dependent carboligases, a multienzyme photobiocatalytic cascade enables the stereoselective synthesis of polysubstituted unnatural prolines, including 2,5-anti-stereoisomers that remain challenging to access by other methods.

Science, Volume 389, Issue 6767, September 2025.