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•Design of artificial metalloenzymes has achieved significant progress in the last decade.•Artificial metalloenzymes were designed from single to multiple active sites in native or de ...novo proteins.•Artificial metalloenzymes exhibit diverse functions, even beyond those of natural metalloenzymes.•The progress elucidates the structure-function relationship of natural metalloenzymes.•The progress provides clues for design of advanced artificial metalloenzymes with potential applications.
Artificial metalloenzymes combine the advantages of both natural enzymes and chemically synthesized models, which have achieved significant progress in the last decade. This review summarizes the recent achievements in rational design of metalloenzymes from single to multiple active sites in natural or de novo protein scaffolds, with a diverse range of functionalities, even beyond those of natural metalloenzymes. These achievements include construction of mononuclear active site by metal substitution or incorporation, design of homo- or hetero-dinuclear site, introduction of Fe-sulfur or other metal clusters, reconstitution of metallo-porphyrins or other metal complexes, and design of dual or multiple active sites in single, dimeric proteins, de novo proteins, protein-protein interfaces, as well as protein oligomers and polymers. Other new trends in recent designs are also discussed. The progress not only elucidates the structural and functional relationship of natural metalloenzymes, but also provides practical clues for design of advanced artificial metalloenzymes with potential applications.
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•Biodegradation of environmental pollutants has been favored for decades.•Significant progress has been made in the biodegradation of aromatic pollutants by metalloenzymes.•Both ...native and artificial metalloenzymes have been applied for biodegradation.•The progress sheds light on the structure-function relationship of metalloenzymes.•The progress provides clues for applications of metalloenzymes in environmental protection.
Environmental security is closely related to public health. Aromatic pollutants constitute a class of hazardous environmental chemicals, such as halophenols and polycyclic aromatic hydrocarbons. Biodegradation of environmental pollutants has been favored for decades. As reviewed herein, significant progress has been made in biodegradation of aromatic pollutants by native metalloenzymes, including heme enzymes (peroxidases and cytochrome P450s), non-heme iron-containing enzymes (Rieske dioxygenases), and copper-containing enzymes (catechol oxidase, tyrosinase, and laccase), and artificial metalloenzymes, including engineered myoglobins, designed manganese peroxidase and de novo designed metalloenzymes, such as those in helical bundles and peptide assemblies, as well as synthetic structural and functional models of natural enzymes. These advances shed light on the structure–function relationship of metalloenzymes, providing clues for potential applications in environmental protection. Future directions for making full use of native and artificial metalloenzymes in environmental science are also prospected.
In this work, several commonly used conductive substrates as electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under alkaline conditions were studied, ...including nickel foam (Ni foam), copper foam (Cu foam), nickel mesh (Ni mesh) and stainless steel mesh (SS mesh). Ni foam and SS mesh are demonstrated as high-performance and stable electrocatalysts for HER and OER, respectively. For HER, Ni foam exhibited an overpotential of 0.217 V at a current density of 10 mA cm
−2
with a Tafel slope of 130 mV dec
−1
, which were larger than that of the commercial Pt/C catalyst, but smaller than that of the other conductive substrates. Meanwhile, the SS mesh showed the best electrocatalytic performance for OER with an overpotential of 0.277 V at a current density of 10 mA cm
−2
and a Tafel slope of 51 mV dec
−1
. Its electrocatalytic performance not only exceeded those of the other conductive substrates but also the commercial RuO
2
catalyst. Moreover, both Ni foam and SS mesh exhibited high stability during HER and OER, respectively. Furthermore, in the two-electrode system with Ni foam used as the cathode and SS mesh used as the anode, they enable a current density of 10 mA cm
−2
at a small cell voltage of 1.74 V. This value is comparable to or exceeding the values of previously reported electrocatalysts for overall water splitting. In addition, NiO on the surface of Ni foam may be the real active species for HER, NiO and FeO
x
on the surface of SS mesh may be the active species for OER. The abundant and commercial availability, long-term stability and low-cost property of nickel foam and stainless steel mesh enable their large-scale practical application in water splitting.
Efficient electrocatalytic overall water splitting is achieved with commercially-available and low-cost nickel foam and stainless steel mesh as cathode and anode electrodes.
Heme proteins are crucial for biological systems by performing diverse functions. Nature has evolved diverse approaches to fine-tune the structure and function of heme proteins, of which ...post-translational modification (PTM) is a primary method. As reviewed herein, a multitude of PTMs have been discovered for heme proteins in the last several decades, including heme-protein cross-links with heme side chains (Cys-heme, Tyr-heme and Asp/Glu-heme, etc) or porphyrin ring (Lys-heme and Tyr-heme, etc), heme modifications (sulfheme and nitriheme, etc), amino acids cross-links between two or among multiple residues (Cys-Cys, Tyr-His, Tyr-Cys, Met-Tyr-Trp, etc), and amino acids modifications by oxidation, nitration, phosphorylation and glycation, etc. With the development of research methods and advances in research techniques, deep insights have been obtained for the formation mechanisms of PTMs, as well as their effects on the structure and function of heme proteins. Moreover, some positive PTMs have been successfully applied to create artificial heme proteins with advanced functions, whereas some negative PTMs have been regulated by rational design of inhibitors. The tremendous progress, together with those ongoing, will make it possible to rationally control the diverse PTMs of heme proteins, especially those associated with human diseases, toward our desired goals for a better life.
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•A multitude of post-translational modifications (PTMs) have been discovered for heme proteins.•Deep insights have been obtained for PTMs and their structural and functional consequences.•Positive PTMs have been applied to create functional artificial heme proteins.•Negative PTMs have been regulated by rational design of inhibitors.•It is possible to control the diverse PTMs of heme proteins toward our desired goals.
Environmental pollutants, such as industrial dyes and halophenols, are harmful to human health, which urgently demand degradation. Bioremediation has been shown to be a cost‐effective and ecofriendly ...approach. As reviewed herein, significant progress has been made in the last decade for biodegradation of both industrial dyes and halophenols, by engineering of native dye‐decolorizing peroxidases (DyPs) and dehaloperoxidases (DHPs), and by design of artificial heme enzymes in both native and de novo protein scaffolds. The catalytic efficiency of artificial DyPs and DHPs can be rationally designed comparable to or even beyond those of natural counterparts. The enzymes are on their way from laboratory to industry and will play more crucial roles in environmental protection toward a green future.
Metalloproteins and metalloenzymes play important roles in biological systems by using the limited metal ions, complexes, and clusters that are associated with the protein matrix. The design of ...artificial metalloproteins and metalloenzymes not only reveals the structure and function relationship of natural proteins, but also enables the synthesis of artificial proteins and enzymes with improved properties and functions. Acknowledging the progress in rational design from single to multiple active sites, this review focuses on recent achievements in the design of artificial metalloproteins and metalloenzymes with metal clusters, including zinc clusters, cadmium clusters, iron-sulfur clusters, and copper-sulfur clusters, as well as noble metal clusters and others. These metal clusters were designed in both native and de novo protein scaffolds for structural roles, electron transfer, or catalysis. Some synthetic metal clusters as functional models of native enzymes are also discussed. These achievements provide valuable insights for deep understanding of the natural proteins and enzymes, and practical clues for the further design of artificial enzymes with functions comparable or even beyond those of natural counterparts.
Globins, such as myoglobin (Mb) and neuroglobin (Ngb), are ideal protein scaffolds for the design of functional metalloenzymes. To date, numerous approaches have been developed for enzyme design. ...This review presents a summary of the progress made in the design of functional metalloenzymes based on Mb and Ngb, with a focus on the exploitation of covalent interactions, including coordination bonds and covalent modifications. These include the construction of a metal-binding site, the incorporation of a non-native metal cofactor, the formation of Cys/Tyr-heme covalent links, and the design of disulfide bonds, as well as other Cys-covalent modifications. As exemplified by recent studies from our group and others, the designed metalloenzymes have potential applications in biocatalysis and bioconversions. Furthermore, we discuss the current trends in the design of functional metalloenzymes and highlight the importance of covalent interactions in the design of functional metalloenzymes.
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•Progress has been made in the design of functional metalloenzymes based on myoglobin (Mb)/Neuroglobin (Ngb) by exploring covalent interactions.•A metal-binding site has been constructed in Mb to generate enzymes with a hetero-dinuclear center.•Mb has been reconstituted with non-native metal cofactor to generate artificial enzymes.•The formation of Cys/Tyr-heme covalent links regulates the structure and function of Mb/Ngb.•The design of disulfide bonds in Mb/Ngb confers functional heme enzymes for biocatalysis.
Noncovalent weak interactions hydrophobic interaction and hydrogen (H)-bond play crucial roles in controlling the functions of biomolecules, and thus have been used to design artificial ...metalloproteins/metalloenzymes during the past few decades. In this review, we focus on the recent progresses in protein design by tuning the noncovalent interactions, including hydrophobic and H-bonding interactions. The topics include redesign and reuse of the heme pocket and other protein scaffolds, design of the heme protein interface, and de novo design of metalloproteins. The informations not only give insights into the metalloenzyme reaction mechanisms but also provide new reactions for future applications.
A mild and eco-friendly visible-light-induced decarboxylative acylation of quinoxalin-2(1
H
)-ones and α-oxo carboxylic acids with ambient air as the sole oxidant at room temperature was established. ...The reaction proceeded efficiently without any metal catalysts, strong oxidants or external-photosensitizers, ultimately reducing the generation of waste.
An eco-friendly visible-light-induced decarboxylative acylation of quinoxalin-2(1
H
)-ones and α-oxo carboxylic acids with air as the oxidant under external-photocatalyst-free conditions was established.
IMPORTANCE: The antiepileptic drug phenytoin can cause cutaneous adverse reactions, ranging from maculopapular exanthema to severe cutaneous adverse reactions, which include drug reactions with ...eosinophilia and systemic symptoms, Stevens-Johnson syndrome, and toxic epidermal necrolysis. The pharmacogenomic basis of phenytoin-related severe cutaneous adverse reactions remains unknown. OBJECTIVE: To investigate the genetic factors associated with phenytoin-related severe cutaneous adverse reactions. DESIGN, SETTING, AND PARTICIPANTS: Case-control study conducted in 2002-2014 among 105 cases with phenytoin-related severe cutaneous adverse reactions (n=61 Stevens-Johnson syndrome/toxic epidermal necrolysis and n=44 drug reactions with eosinophilia and systemic symptoms), 78 cases with maculopapular exanthema, 130 phenytoin-tolerant control participants, and 3655 population controls from Taiwan, Japan, and Malaysia. A genome-wide association study (GWAS), direct sequencing of the associated loci, and replication analysis were conducted using the samples from Taiwan. The initial GWAS included samples of 60 cases with phenytoin-related severe cutaneous adverse reactions and 412 population controls from Taiwan. The results were validated in (1) 30 cases with severe cutaneous adverse reactions and 130 phenytoin-tolerant controls from Taiwan, (2) 9 patients with Stevens-Johnson syndrome/toxic epidermal necrolysis and 2869 population controls from Japan, and (3) 6 cases and 374 population controls from Malaysia. MAIN OUTCOMES AND MEASURES: Specific genetic factors associated with phenytoin-related severe cutaneous adverse reactions. RESULTS: The GWAS discovered a cluster of 16 single-nucleotide polymorphisms in CYP2C genes at 10q23.33 that reached genome-wide significance. Direct sequencing of CYP2C identified missense variant rs1057910 (CYP2C9*3) that showed significant association with phenytoin-related severe cutaneous adverse reactions (odds ratio, 12; 95% CI, 6.6-20; P=1.1 × 10−17). The statistically significant association between CYP2C9*3 and phenytoin-related severe cutaneous adverse reactions was observed in additional samples from Taiwan, Japan, and Malaysia. A meta-analysis using the data from the 3 populations showed an overall odds ratio of 11 (95% CI, 6.2-18; z=8.58; P < .00001) for CYP2C9*3 association with phenytoin-related severe cutaneous adverse reactions. Delayed clearance of plasma phenytoin was detected in patients with severe cutaneous adverse reactions, especially CYP2C9*3 carriers, providing a functional link of the associated variants to the disease. CONCLUSIONS AND RELEVANCE: This study identified CYP2C variants, including CYP2C9*3, known to reduce drug clearance, as important genetic factors associated with phenytoin-related severe cutaneous adverse reactions.
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