A Library of ROS‐Catalytic Metalloenzyme Mimics with Atomic Metal Centers

Abstract

MetalN-coordinated centers supported by carbonaceous substrates have emerged as promising artificial metalloenzymes (AMEs) to mimic the biocatalytic effects of their natural counterparts. However, the synthesis of well-defined AMEs that contain different atomic metalN centers but present similar physicochemical and coordination structures remains a substantial challenge. Here, 20 different types of AMEs with similar geometries and welldefined atomic metalN-coordinated centers are synthesized to compare and disclose the catalytic activities, substrate selectivities, kinetics, and reactive oxygen species (ROS) products. Their oxidase (OXD)-, peroxidase (POD)-, and halogen peroxidase (HPO)-mimetic catalytic behaviors are systematically explored. The Fe-AME shows the highest OXD-and HPO-mimetic activities compared to the other AMEs due to its high v max (0.927 × 10 −6 m s −1 ) and low K m (1.070 × 10 −3 m), while the Cu-AME displays the best POD-like performance. Furthermore, theoretical calculation reveals that the ROS-catalytic paths and activities are highly related to the electronic structures of the metal centers. Benefiting from its facile adsorption of H 2 O 2 molecule and lower energy barrier to generating •O 2 − , the Fe-AME displays higher ROS-catalytic performances than the Mn-AME. The engineered AMEs show not only remarkably high ROS-catalytic performances but also provide new guidance toward developing metalN-coordinated biocatalysts for broad application fields.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202200255.

Highly Antibacterial and Adhesive Hyaluronic Acid Hydrogel for Wound Repair

“…Therefore, the measurement of singlet oxygen yield is crucial to evaluate the antibacterial efficiency of hydrogels. Because TPP is hydrophobic, an amphiphilic copolymer (PEO- b -PDLA, M w = 3700) was used to encapsulate TPP to form nanoparticles (TPP-PEO- b -PDLA) for the singlet oxygen yield determination according to previous work. − In Figure a, TPP nanoparticles (TPP-PEO-b-PDLA) and TPP hydrogels (HAMA-TPP-DMA) with the same TPP content (1 mg/mL) exhibit weak absorption at 650, 590, 550, and 516 nm (Q-band absorption) and strong absorption at 420 nm (S-band absorption). 1, 3-Diphenylisobenzofuran (DPBF) was used as a probe to estimate the capability of TPP-PEO- b -PDLA and HAMA-TPP-DMA to produce singlet oxygen.…”

Multifaceted Catalytic ROS‐Scavenging via Electronic Modulated Metal Oxides for Regulating Stem Cell Fate

“…The Co 2p spectrum of Co 3 O 4 displays two major peaks around 795 and 780 eV, [47,48] which match well to the Co 2p 1/2 and Co 2p 3/2 spin-orbit peaks of Co 3 O 4 (Figure 4f). The Co 2p 3/2 can be deconvoluted to binding energies of Co 3+ (780.04 eV) and Co 2+ (781.60 eV); [49,50] the ratio of Co 2+ increases with the higher content of Mn atoms. [47,51] The Mn 2p spectra in Figure 4g show that all Mn species (Mn 2+ , Mn 3+ , and Mn 4+ ) shift to the higher binding energy of Mn-Co 3 O 4 compared to the bare Mn 3 O 4 .…”

Insights on catalytic mechanism of CeO2 as multiple nanozymes

“…The concept of nanozymes is an interdisciplinary field, which bridges the disciplines of enzymology and heterogeneous catalysis. To date, the catalytic performance of nanozymes is generally analyzed by the Michaelis-Menten equation, in which two parameters of k cat and K m are used to describe the catalytic reaction rate and adsorption affinity of substrates on the surfaces of nanozymes, respectively [7,[26][27][28][29][30]. This method is practically adopted to understand the catalytic kinetics of natural enzymes, which cannot accurately reflect the catalytic mechanism of nanozymes.…”