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Nanomaterials excel in mimicking the structure and function of natural enzymes while being far more interesting in terms of structural stability, functional versatility, recyclability, and large‐scale preparation. Herein, the story assembles hemin, histidine analogs, and G‐quadruplex DNA in a catalytically competent supramolecular assembly referred to as assembly‐activated hemin enzyme (AA‐heminzyme). The catalytic properties of AA‐heminzyme are investigated both in silico (by molecular docking and quantum chemical calculations) and in vitro (notably through a systematic comparison with its natural counterpart horseradish peroxidase, HRP). It is found that this artificial system is not only as efficient as HRP to oxidize various substrates (with a turnover number kcat of 115 s−1) but also more practically convenient (displaying better thermal stability, recoverability, and editability) and more economically viable, with a catalytic cost amounting to <10% of that of HRP. The strategic interest of AA‐heminzyme is further demonstrated for both industrial wastewater remediation and biomarker detection (notably glutathione, for which the cost is decreased by 98% as compared to commercial kits). [ABSTRACT FROM AUTHOR]

The introduction of an abiological catalytic group into the binding pocket of a protein host allows for the expansion of enzyme chemistries. Here, we report the generation of an artificial enzyme by genetic encoding of a non‐canonical amino acid that contains a secondary amine side chain. The non‐canonical amino acid and the binding pocket function synergistically to catalyze the asymmetric nitrocyclopropanation of α,β‐unsaturated aldehydes by the iminium activation mechanism. The designer enzyme was evolved to an optimal variant that catalyzes the reaction at high conversions with high diastereo‐ and enantioselectivity. This work demonstrates the application of genetic code expansion in enzyme design and expands the scope of enzyme‐catalyzed abiological reactions. [ABSTRACT FROM AUTHOR]

Enzymes have gained their unique efficiency and catalytic activity through billions of years of evolution, perfecting their active site to a desired reaction. Inspired by nature, a novel enzyme‐mimicking platform is designed based on stable protein 1 (SP1) to create a nano‐compartment that mimics peroxidase activity. The biohybrid reveals enhanced activity over the hemin cofactor alone and improved stability in organic solvents in comparison to native peroxidase. Furthermore, the utilization of the obtained biohybrid in an optical glucose biosensing platform is shown. The biohybrid crystallographic structure is solved, indicating that the SP1 structure is not affected by the hemin coordination. This work opens the path for developing new cofactor binding centers in engineered protein scaffolds for various artificial catalytic processes. [ABSTRACT FROM AUTHOR]

Secondary amines, due to their reactivity, can transform protein templates into catalytically active entities, accelerating the development of artificial enzymes. However, existing methods, predominantly reliant on modified ligands or N‐terminal prolines, impose significant limitations on template selection. In this study, genetic code expansion was used to break this boundary, enabling secondary amines to be incorporated into alternative proteins and positions of choice. Pyrrolysine analogues carrying different secondary amines could be incorporated into superfolder green fluorescent protein (sfGFP), multidrug‐binding LmrR and nucleotide‐binding dihydrofolate reductase (DHFR). Notably, the analogue containing a D‐proline moiety demonstrated both proteolytic stability and catalytic activity, conferring LmrR and DHFR with the desired transfer hydrogenation activity. While the LmrR variants were confined to the biomimetic 1‐benzyl‐1,4‐dihydronicotinamide (BNAH) as the hydride source, the optimal DHFR variant favorably used the pro‐R hydride from NADPH for stereoselective reactions (e.r. up to 92 : 8), highlighting that a switch of protein template could broaden the nucleophile option for catalysis. Owing to the cofactor compatibility, the DHFR‐based secondary amine catalysis could be integrated into an enzymatic recycling scheme. This established method shows substantial potential in enzyme design, applicable from studies on enzyme evolution to the development of new biocatalysts. [ABSTRACT FROM AUTHOR]

Abstract Nanomaterials excel in mimicking the structure and function of natural enzymes while being far more interesting in terms of structural stability, functional versatility, recyclability, and large‐scale preparation. Herein, the story assembles hemin, histidine analogs, and G‐quadruplex DNA in a catalytically competent supramolecular assembly referred to as assembly‐activated hemin enzyme (AA‐heminzyme). The catalytic properties of AA‐heminzyme are investigated both in silico (by molecular docking and quantum chemical calculations) and in vitro (notably through a systematic comparison with its natural counterpart horseradish peroxidase, HRP). It is found that this artificial system is not only as efficient as HRP to oxidize various substrates (with a turnover number kcat of 115 s−1) but also more practically convenient (displaying better thermal stability, recoverability, and editability) and more economically viable, with a catalytic cost amounting to

The folding of proteins into intricate three‐dimensional structures to achieve biological functions, such as catalysis, is governed by both kinetic and thermodynamic controls. The quest to design artificial enzymes using minimalist peptides seeks to emulate supramolecular structures existing in a catalytically active state. Drawing inspiration from the nuanced process of protein folding, our study explores the enzyme‐like activity of amphiphilic peptide nanosystems in both equilibrium and non‐equilibrium states, featuring the formation of supramolecular nanofibrils and nanosheets. In contrast to thermodynamically stable nanosheets, the kinetically trapped nanofibrils exhibit dynamic characteristics (e.g. rapid molecular exchange and relatively weak intermolecular packing), resulting in a higher hydrolase‐mimicking activity. We emphasize that a supramolecular microenvironment characterized by an optimal local polarity, microviscosity, and β‐sheet hydrogen bonding is conducive to both substrate binding and ester bond hydrolysis. Our work underscores the pivotal role of both thermodynamic and kinetic control in impacting biomimetic catalysis and sheds a light on the development of artificial enzymes. [ABSTRACT FROM AUTHOR]

Enzymes have gained their unique efficiency and catalytic activity through billions of years of evolution, perfecting their active site to a desired reaction. Inspired by nature, a novel enzyme‐mimicking platform is designed based on stable protein 1 (SP1) to create a nano‐compartment that mimics peroxidase activity. The biohybrid reveals enhanced activity over the hemin cofactor alone and improved stability in organic solvents in comparison to native peroxidase. Furthermore, the utilization of the obtained biohybrid in an optical glucose biosensing platform is shown. The biohybrid crystallographic structure is solved, indicating that the SP1 structure is not affected by the hemin coordination. This work opens the path for developing new cofactor binding centers in engineered protein scaffolds for various artificial catalytic processes.

Engineering metallobiocatalysts is a promising approach to addressing challenges in energy-relevant electrocatalysis and photocatalysis. The design freedom provided by semisynthetic and fully synthetic approaches to catalyst design allows researchers to demonstrate how structural modifications can improve selectivity and activity of biocatalysts. Furthermore, the provision of a superstructure in many metallobiocatalysts facilitates active-site microenvironment engineering. Recurring themes include the role of the biomolecular scaffold in enhancing reactivity in water and catalyst robustness, the impact of the outer sphere on reactivity, and the importance of tuning system components in full system optimization. In this perspective, recent strategies to design and modify novel biocatalysts, understand proton and electron transfer mechanisms, and tune system activity by modifying catalysts and system conditions are highlighted within the field of energy-related catalysis. Opportunities in this field include developing robust structure-function relationships to support approaches to engineering second-sphere interactions and identifying ways to enhance biocatalyst activity over time., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Rationally-engineered functional biomaterials offer the opportunity to interface with complex biology in a predictive, precise, yet dynamic way to reprogram their behaviour and correct shortcomings. Success here may lead to a desired therapeutic effect against life-threatening diseases, such as cancer. Here, we engineered "Crab"-like artificial ribonucleases through coupling of peptide and nucleic acid building blocks, capable of operating alongside and synergistically with intracellular enzymes (RNase H and AGO2) for potent destruction of oncogenic microRNAs. "Crab"-like configuration of two catalytic peptides ("pincers") flanking the recognition oligonucleotide was instrumental here in providing increased catalytic turnover, leading to ≈30-fold decrease in miRNA half-life as compared with that for " single-pincer" conjugates. Dynamic modeling of miRNA cleavage illustrated how such design enabled "Crabs" to drive catalytic turnover through simultaneous attacks at different locations of the RNA-DNA heteroduplex, presumably by producing smaller cleavage products and by providing toeholds for competitive displacement by intact miRNA strands. miRNA cleavage at the 5′-site, spreading further into double-stranded region, likely provided a synergy for RNase H1 through demolition of its loading region, thus facilitating enzyme turnover. Such synergy was critical for sustaining persistent disposal of continually-emerging oncogenic miRNAs. A single exposure to the best structural variant (Crab-p-21) prior to transplantation into mice suppressed their malignant properties and reduced primary tumor volume (by 85 %) in MCF-7 murine xenograft models. [Display omitted] [ABSTRACT FROM AUTHOR]

• CuBSA (Cu-bovine serum albumin nanoenzymes) was prepared by binding BSA to Cu2+. • CuBSA has a natural superoxide dismutase-like structure and excellent antioxidant capacity. • CuBSA has good bactericidal properties and is biocompatible. • Antimicrobial and antioxidant capabilities were obtained for composite films containing CuBSA. As monofunctional packaging becomes less able to satisfy the need for environmentally friendly convenience, functionalized packaging is becoming more and more significant in food applications. In this study, a biomimetic artificial nano-enzyme, bovine serum albumin (BSA) chelated with copper ions (CuBSA), was constructed by imitating the structure of natural superoxide dismutase (SOD). This novel CuBSA metallo-nanoenzyme possesses distinct SOD-like enzyme activity, antibacterial capabilities, as well as thermal stability and biocompatibility. With CuBSA as excellent filler, the carrageenan-based nanocomposite films were obtained, showing excellent performance in retarding enzymatic browning and inhibiting microbial attack on fresh-cut apples and figs, even stored at room temperature. More importantly, this new composite film is low-cost and simple to be synthesized for large-scale use. [ABSTRACT FROM AUTHOR]

Development of hetero-atom rich porous organic polymers (POPs) in facile and easy accessible methods are of significant importance to broad application potentials and enrich diversity of such materials. Here, a bidirectional adjustment strategy, starting with amino and aldehyde monomers, concurrently, was used for the rational preparation of N-rich aminal-linked POPs with customized structure and function. Five novel ferrocene-based aminal-linked POPs, were facilely fabricated via the one-pot catalyst-free Schiff base polycondensation between the 1,1′-Ferrocene dicarboxaldehyde and different types of triazine-bearing monomers with diverse geometrical features and functions (Porphyrin, cationic viologen, Ferrocene, 1,4,7,10-tetraazacyclododecane, and benzyl). The concurrent introduction of Ferrocene (redox-active) and triazine-Porphyrin (photoactive) endowed remarkable mimicking peroxidase-like activity and excellent photothermal and photodynamic activity with Fc-TDPP, which could be used as a broad spectrum fungicide, exerting photothermal enhanced photodynamic and enzyme antibacterial therapy. Notably, in vitro and in vivo experiments confirmed Fc-TDPP could not only kill S. aureus and E. coli quickly and efficiently, but also significantly accelerate the repairing of open wounds with S. aureus -infection. The as-proposed strategy are available for the low-cost constructing N-rich POPs with specific structure and functions targeted for wide potential applications in various fields. • Bidirectionally regulated strategy is adopted to develop porous PPANs. • Ferrocene-based aminal-linked PPANs with POD enzyme activity is prepared. • Fc-TDPP amalgamated the Ferrocene and Porphyrin repeated unites. • Fc-TDPP featured remarkable POD activity and excellent photo activity. • Fc-TDPP exerted photothermal-amplified synergistic antibacterial therapy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Homopolymers and copolymers with histidine COOH, CONH 2 , and NH 2 were synthesized. • The polymers were incubated with bovine serum albumin and analyzed by SDS-PAGE. • Polymers with histidine COOH cleaved bovine serum albumin at pH 4.2 and pH 7.4. • Several polymers with specific histidine densities showed activity at pH 8.0. • Polymers with specific COOH density exhibited varying digestion patterns based on pH. Artificial enzymes with serine, aspartic acid, and histidine that mimic the catalytic triad of serine proteases have been studied. However, they were mainly investigated for their cleavage activity on low molecular-weight esters and amides, and there has been a lack of knowledge about their protein cleavage activity. We previously found that not only ternary polyacrylamides with serine, aspartic acid, and histidine but also homo-polyacrylamides with a single type of amino acid cleaved bovine and human serum albumins. These results suggested that the carboxy group, a common functional group in active polymers, may be involved in the expression of activity. In this study, we synthesized histidine polymers in which the carboxy group was changed to a carboxamido or amino group and investigated the relationships between structure and activity. Histidine homopolymers and histidine-acrylamide copolymers were incubated with bovine serum albumin at 37 °C for one week under different pH conditions and then analyzed by sodium dodecyl-sulfate polyacrylamide gel electrophoresis. In the case of histidine homopolymers, the carboxy-type homopolymers were active under weakly acidic to neutral conditions, while the carboxamido- and amino-type homopolymers were not active regardless of liquid properties. In the case of histidine-acrylamide copolymers, their activity was essentially the same as that of each type of histidine homopolymer, but for all types of copolymers, activity appeared under weakly basic conditions when the histidine monomer units were of a specific density. The carboxy-type copolymers with dual-mode activity showed different degradation patterns of bovine serum albumin under acidic and basic conditions. The structural features common to the active homopolymers and copolymers suggested that the carboxy group contributes to the activity under weakly acidic to neutral conditions, while the imidazole group of the histidine side chain and its density contribute to the activity under weakly basic conditions. [ABSTRACT FROM AUTHOR]

A proline-based artificial enzyme is prepared by grafting the l-proline moieties onto the surface of bovine serum albumin (BSA) protein through atom transfer radical polymerization (ATRP). The artificial enzyme, the BSA-PolyProline conjugate, prefers to catalyze the formation of unsaturated ketones rather than β-hydroxy ketones in the reaction between acetone and aldehydes, which is difficult to achieve in free-proline catalysis. The altered reaction selectivity is ascribed to the locally concentrated l-proline moieties surrounding the BSA molecule, indicating a microenvironmental effect-induced switching of the reaction mechanism. Taking advantage of this selectivity, we used this artificial enzyme in conjunction with a natural enzyme, old yellow enzyme 1 (OYE1), to demonstrate a simple synthesis of different aliphatic ketones from acetone and aldehydes via tandem catalysis.